Sectioned busbar system with bypass

The bypass bus system allows you to repair a machine for an hour, at any time, or replace it with a machine.

Suitable for voltages of 110 - 500 kV. BB allows you to carry out repairs without any interruption of life. SHSV (tire tire service) - without interruption of life, transfer the accessory from one tire system to another and take one of the tire systems out for repair.

Advantages:

1. In the event of a short circuit in one bus system, only half of the power supply is wasted.

2. When one bus system is taken out for repair, life is transferred to another without interrupting life.

3. If it is necessary to repair one of the equipment, it must be replaced without interruption of life.

Nedoliky:

1. In the event of a short circuit on the line of the video processor, you can perform a breaker failure (breaker failure device) and turn on all devices of the same bus system to which the faulty connection is connected.

2. In the event of a short circuit, half of the income is spent on one of the ZOSHs, and if in case of which the SHSV was released, then all the additions are lost.

Repeated busbar scheme

The scheme is also called “3/2” – 3 bonuses for 2 additions.

a) one-and-a-half scheme of busbars without drawing attached

Advantages:

1. In the event of a short circuit on one of the ZOSHs, the 1st and 3rd rows are switched on, and all accessories are lost in operation.

2. When the 1st or 2nd SSH is out for repair, no folding reconnection is required. It is necessary to turn on the chemicals of the 1st and 3rd rows.

3. In the event of a short circuit on the line, 2 switches are switched on and one of them is switched off, or the bus system is extinguished without losing power, or one line or one generator is lost.

4. When repairing one of the faults and short circuits, the other costs of life are not taken into account. However, the blocks are visible along their line.

Nedoliky:

1. More expensive, lower front schemes, because Revenge from the author times more vimikachiv.

2. Great operational costs for the use of a large number of repair robots, because when the skin is connected, 2 circuits are connected - great wear and tear on the circuits.

3. If one of the circuit breakers of the 1st or 3rd row is under repair and there is a short circuit on one of the input fields, then the other input field is wasted.

4. The relay protection is highly foldable.

b) one-and-a-half scheme with cherguvannyam prєdnan

The advantage of this scheme over the previous one lies in the fact that when repairing the 2nd row of circuit breakers and when repairing the 1st or 3rd row of circuit breakers in the event of a short circuit on the line, the amount of money spent on the block will be 2 times less. Whenever a vehicle is repaired, there will be a breakdown of the bus system and a loss of revenue when it is being repaired. However, the faulty line can be disconnected by the disconnector and the bus system can be revived once the wasted power supply is renewed.

If in the scheme the number of lanyards will be greater than 5, then the tires are recommended to be sectioned.

The high reliability and flexibility of the circuit is widely used in subdivisions (RU) of 330 – 750 kV at regular power plants.

At node substations, this scheme will stagnate when more and more people are added. With a lower number of connections, the lines are connected to the lanyard with three voltages, and the transformers are connected to the busbars without circuits that form the transformer-busbar block.

Scheme with two bus systems for three connections (scheme 4/3)

The scheme is most effective when the number of lines is 2 times less or more than the number of cores.

It has all the advantages of the one-and-a-half scheme, as well as:

1. Economical (1.33 revenue per added replacement 1.5);

2. Sectionalization of busbars is required when the number added is 15 or more;

3. The reliability of the circuits is practically not reduced if two lines and one transformer are added to the lanyard instead of one line and one transformer.

Nedoliky:

1. All shortcomings, like attached schemes 3/2;

2. In connection with this, in this scheme there are 2 times more benefits in the middle row, lower than in the 3/2 scheme, then with these benefits, the likelihood of spending another gain will be greater.

The scheme can be combined with 1, 2, 3 or 4 row layouts. The most distant is the noble growth of Vimikachi:

LR is installed to compensate for the emnestic flow that is generated by the power line at 500 kV and above.

LECTURE NOTES OF DISCIPLINES

“ELECTRICAL PART OF STATIONS and PIDSTATIONS” part 2

For bachelors directly _"Energy and electrical engineering"_140400

for profiles: “ Electric power systems and connections”, “Electric power stations”, “Relay protection and automation of electric power systems”, “Electric supply”

Art. Cashier Galkin A.I.

Novocherkassk 2014

Schemes of separate outbuildings

Previously, in the 1st part, the formulation of the subdivision (RU), as an element of the structural diagram of a power facility (stations or substations), was given.

RU - this installation is intended for receiving and distributing electrical energy on one voltage and placing switching devices (switches and switches, and at substations there may be switches and short-circuiters), neither the equipment (transformers, power supply, voltage) nor conductors that will ensure the sound language between devices.

There is a great variety of switchgear circuits, which vary in reliability, operational flexibility and, consequently, versatility. There is a place for staleness: where there is greater reliability and operational flexibility of the RU – this is where there is greater versatility. Different types are connected to RU appropriation. Before the main ones acceded to you can include: power lines ( W), power transformers ( T) that generator ( G) (as a result of the generator voltage at the thermal power plant).

All the different types of switchgear can be divided into circuits RU with collapsible tires that circuits RU without assembled tires . The rest of your money can be divided into RU for simple schemes and on RU based on ring circuits .(rich-cutters) In many switchgear circuits, it is possible to override parts of the circuit, which includes three sequentially switched on elements: disconnector ( QS1), vimicach ( Q), strumu transformer ( T.A.) and another roz'ednuvach ( QS2).

Let's look at the actions of the most extensive RU schemes in the skin of the designated groups.

RU for simpler schemes. RU behind simpler circuits are different variants of line blocks - transformer or locations, which are not typical for power plants and cause stagnation at high voltage substations with low power supply dnan. Here you can add an entry-exit diagram.

Variants of these schemes are shown in Fig. 8.1. Here the lines are shown by arrows, and the power transformers are shown by crossing (voltage regulation under voltage). Lines and power transformers are not elements of the switchgear, but are an attachment to the switchgear. The switchgear diagram shows the circuit breakers, connectors, power transformers and voltage transformers.

RU behind the circuit block line - transformer (Fig. 8.1, b) is installed at dead-end single-transformer substations like HV switchgear with one life line. At double-transformer dead-end substations with two live lines, install a switchgear behind the circuit of two line blocks - a transformer with switches and a non-automatic jumper on the side of the lines (Fig. 8.1, V).

RU behind the circuit diagram (Fig. 8.1, Gі d) be installed on the high side of transit substations, which are included in the divisions of the transit line. At the boundaries of the substation, the transit of pressure is relieved by an automatic jumper to accommodate the liquid. In addition, there are two more symbols in the township scheme. They can be installed either on the side of power transformers (Fig. 8.1, G) or on the side of the lines (Fig. 8.1, d). For an hour to repair the elements of the automatic jumper, so as not to impair the transit of tension, a non-automatic jumper (without a vimikach) was transferred, which is called a repair one.

Rice. 8.1. RU for simpler schemes:

A- block from disconnection; b- those same, ale z vimikachem; V- two blocks with switches and a non-automatic jumper on the side of the lines; G- a place with circuit breakers in the lancets of transformers and a repair jumper on the side of the transformers;

Prodovzhennya rice. 8.1:

d- a place with vimikachs in the lines and a repair jumper on the side of the lines; e- Entry-exit

At transit single-transformer substations, install the switchgear behind the input-output circuit (Fig. 8.1, e). Here there is also a repair reconnection without vimikach

RU circuits with busbars. RU with assembled tires is folded with collected tires, to which divisions are connected appropriation. Before the main ones acceded to can include: power lines, power transformers and generators (as a result of the generator voltage switchgear).

With run-flat tires Busbars of rigid or flexible construction are called that carry small electrical supports intended for connecting the power supply.

In schemes with assembled busbars, the main accessories include the following devices. A switch is installed on the side of the busbar, which is called bus, then a vimikac is installed, after the vim, a transformer is installed, and then another connector is attached to the side, which is called linear or transformer (due to d prєdnannya).

Among the faceless RUs with assembled tires you can see the following:

· switchgear circuits with one operating bus system (called sectional);

· switchgear circuits with one operating and bypass bus systems;

· switchgear circuits with two operating and bypass bus systems;

· circuits with two operating bus systems and three vibrations for two connections.

Switchgear circuit with one operating bus system It is simple, straightforward, economical, but does not have sufficient operational flexibility. When repairing a tire or other device in Lancia, the tire is consumed, and when repairing a tire or section of tires, all the parts associated with that tire (section) are consumed.

Rice. 8.2 Switchgear diagram with one operating bus system: a – non-sectional; b - sectioned with vimikach.

At power plants, such a scheme in a sectional version can be used in switchgear circuits for supplying 6 kV power demand or in a generator switchgear 6 - 10 kV at a thermal power plant.

At substations, such a circuit in a sectional version can be used in switchgear circuits on the low voltage side of 6 - 10 kV (35 kV) (PN switchgear).

Switchgear circuit with one operating and bypass bus system installed at stations and substations at a voltage of 110, 220 kV, if the number supplied is less than seven. An important advantage of this scheme is the ability to replace any (one at the moment) vimikac in the lancus acquired during any repair or revision of the vimikac ( QB1 in Fig. 8.3) without interruption of life. The struma bypasses the pump that is being repaired, it is created with the help of a bypass pump and a bypass bus system. Often the working bus system of this circuit is sectioned, as shown in the picture. In the emergency mode of operation, the bypass bus system is not under voltage and the bus connectors ( QSB) disabled. In the switched-off position there is a bypass switch and sockets in your lancet.

The main operations of replacing the vimicach in Lancus and bypassing the rules of commutation are reviewed in the vimicach application Q1 at the Lancjug line W1:

The socket should be switched on in the lancius of the bypass vimikach QB1, moreover, in the case of roses, include the one connected with the same section as W1.

Whose name should I include? QB1 And then apply voltage to the bypass bus. It is necessary to check the insulation of the bypass bus.

At the next moment turn on QB1.

Now, if the insulation level has been verified, turn on the tire outlet QSB1 at lanciusi W1.

I want to turn it on QB1.

Now we have two ways to flow through the stream in Lanzyuzi W1: one through Q1, and the other through QB1.

Now you can connect Q1 and roses in yogo lantsyugu for a vinyatka tire rosette QSB1.

However, this scheme saves the small amount that is spent during the repair of the working tire section of the connections between the attached sections. In short, a circuit with two working bus systems has been added, often using a bypass bus.

Rice. 8.3 Scheme with one operating section and bypass bus system (transformers and voltage are not shown): QSB1, QSB2, QSB3 – bus connectors of the bypass bus system are added to the lanyards; Q1 – vimikach u lanzyuzi prijednannya; QS1 and QS2 – bus and line sockets in lancus connection; QB1 - bypass device; QK1 (QK2) – sectional vimicac.

Switchgear diagram with two operating and bypass bus systems stagnates at voltage RU 110, 220 kV, if the number is not less than seven. In this scheme, part of the accessory is connected to one operating bus (K1), and part is connected to another (K2). Otherwise, the connection can be transferred using an additional QK tire changer and bus connectors connected from one operating bus system to another. (During this operation, splinotic QK And the distributors in this area are guilty of being in a switched-on state.) This should be used when repairing any working tire. The presence of the bypass circuit and the bypass bus gives the same advantages as the front circuit.

Rice. 8.4 Scheme with two working and bypass bus systems (transformers and power supply and voltage not shown): QK – bus-unit pump; QB - bypassing means; K1 – first operating tire system; K2 – another operating bus system; KV – bypass bus system.

Not many circuits, like the first ones, are deprived of those that in the event of an emergency connection, one of the working buses (for example, due to a short circuit on the bus) will be disconnected and the connections between the connected ones will be damaged. ya, tied with this tire.

Scheme with two operating bus systems and three vimikachami for two connections recommended before installation in a switchgear with a voltage of 330 - 750 kV and with a number of six or more added. This scheme achieves high operational efficiency and reliable connection between the additions for emergency and operational situations.

Between the schemes, it can be noted that during repairs or revisions of any device, all connections are lost in operation, and in the event of an emergency disconnection of one of the working buses, the connections between the connections are not lost, so how it works through a tire that was lost in the robot.

Among the shortcomings, you may notice the need for switching to be connected to two devices and the output to be increased. Moreover, in this circuit, the secondary lanyards of the transformers struma are folded, because The strum transformers are then installed in the circuits of the circuits and in order to remove the strum, it is necessary to combine (following Kirchhoff’s first law) the strums of the secondary windings of two transformers.

Rice. 8.5 One-and-a-half diagram of the switchgear (transformers and voltages are not shown): K1 and K2 – working bus systems.

RU circuits based on ring circuits (rich circuits). Get involved in switchgear 110-220 kV and more. In ring schemes (rich circuit schemes), the components connect with each other, forming a ring. A leather element - a line, a transformer - is connected between two adjacent circuits. The simplest ring diagram is the tricutaneous diagram (Fig. 8.6 a). Line W1 is connected to the circuit by circuits Q1, Q2, line W2 - by circuits Q2, Q3, transformer - by circuits Q1, Q3. The addition of more elements to the basic circuit increases the flexibility and reliability of the robot, while the number of components in the circuit does not seem to exceed the number of additions. The trikutnik scheme has three attachments - three benefits, so the scheme is economical.

In circular schemes, the revision of any chemical source is carried out without interrupting any element. So, when revising the vimikach Q1, turn on the same connectors installed on the side of the vimikach. When the damaged line and transformer are lost in operation, the circuit becomes less reliable due to ring rupture. If in this mode there is a short circuit on line W2, the switches Q2 and Q3 are switched on, as a result of which the offending lines and the transformer will be deprived of voltage. All elements of the substation will also be connected in the event of a short circuit on the line and the output of one circuit breaker: for example, in the event of a short circuit on the line W1 and the circuit breaker in the circuit breaker Q1, the circuit breakers Q2 and Q3 are switched on . Possibility of escape

Rice. 8.6 Ring circuits (rich coils) (transformers and voltages are not shown).

The deterioration of the line due to the revision of the chemical pump, as it was determined above all, should lie at the expense of the repair of the chemical pump. Increasing the turnaround time and reliability of chemicals, as well as reducing the cost of repairs, will significantly improve the reliability of the circuits.

Ring circuits are more reliable than other circuits, but there is the possibility of testing any kind of circuit during normal operation of circuits. Testing the circuit with this connection does not disrupt the operation of the connected elements and does not cause unnecessary interruptions in the circuit.

In Fig. 8.6, b A diagram of the chotirikutnik (square) is presented. This scheme is economical (even though it is used), it allows testing and auditing of any device without damaging the operation of its elements. The scheme has high reliability. The connection of all is less reliable, which can happen if the revision of one of the circuits, for example Q1, is damaged, line W2 is damaged, and the circuit of another circuit, Q4, is damaged. When repairing line W2, switch on the switches Q3, Q4 and the connectors installed near the other lines. The connections W1, T1 and T2, which were lost in the work, are added through the contacts Ql, Q2. If T1 is damaged during this period, then the Q2 switch will turn on, the other transformer and the W1 line will be lost from the work, otherwise the transit of pressure will be damaged. Installation of linear outlets QS1 and QS2 takes only a short time.

The advantage of all ring circuits is the elimination of disconnectors from repair work. The number of disconnection operations in such schemes is small.

Up to a few traces, add a folding selection of transformers to the strum, vimikacs and disconnectors. Transformers and struma are installed here, just like in the repeater circuit, in the Lanzygug of Vimikachiv

Head diagram of electrical connectionsElektrostannitziya Abo PIDSTANTSIA - the pepper of the main Elektro -Statatkavanny (generator, transformer, linії), Zbirny tires, komutatovyu, the primary Aparaturi viconasi of them in the nature of spoluki.

The choice of the main circuit is the initial step during the design of the electrical part of the power plant (substation), since it indicates the final storage of elements and connections between them. The main circuit is selected as the output for arranging the electrical connection circuit diagrams, demand circuits, secondary connection circuits, wiring diagrams, etc.

On the chair, the main circuits are displayed in a single-line diagram when all installation elements are turned off. In some cases, it is allowed to display the circuit elements in their operating position.

All elements of the circuit and the connections between them are displayed in accordance with the standards of the unified system of design documentation (USD).

Lower PS are designated for the distribution of energy along the PN limit and the creation of points of connection between the HV limit (switching points). Initially, for choosing the expansion of the PS, there is a grid scheme, for the purpose of which it is intended to live. The optimal tension and radius of the action of the PS is determined by the strength of the tension in the area of ​​its placement and the pattern of the edge of the PS. With a high density of installations, collapsible and unfolded power supply lines, consider the usefulness of a larger HV substation to increase the reliability of life and reduce the cost of maintaining the power supply line. Regulatory documents do not establish the classification of substations beyond their place and method of accession to the limit. Based on the types of network configurations that are set up (section 4.2) and possible schemes for connecting substations, they can be divided into stages (7): dead-ends - live in one (section 4.7, a) or two radial lines pit; Scheme 4.7, a is seen as the first stage of development of the boundary with further transformations into Scheme 4.7, b or 4.7, d; vіdgaluzhnі - that you will have to go through one (7, c) or two (7, d) PL on vіdgaluzhenny; Scheme 4.7, є the first stage of development with subsequent transformations in Scheme 4.7, g or d; passageways - what is needed before the road enters one line with two-way streets (7, d); vuzlov - what comes to the minimum level at the three living lines (7, f, g). The central and pass-through PSs are referred to by the term intermediate, which means the placement of the PS between two border CPUs (or node PSs).
Passage or node substations through which buses flow between adjacent crossing points are called transit. In technical literature and in various regulatory documents, the term “substation support” is sometimes used, which, as a rule, refers to a substation of a higher voltage level (for example, a 220/110 kV substation under the 110 kV threshold). However, this term is used to emphasize the operational role of the PS. Therefore, for the PS, in order to live the voltage limit, it seems necessary to completely use the term life center (LC). In the table 4.3 provides data from a statistical analysis of the frequency of stagnation of the induction of more substation connection schemes at 110–330 kV lines. It is clear from the data that most PSs come to the junction along two lines. There is a trend towards an increase in the number of such schemes due to the change in the part of the PS that is added at the first stage along one line. As a result of the increase in the tension of the junction, the frequency of dead-end and junctional PSs decreases. The widest type of substation 110-330 kV is through-passage. Table 4.3


Analysis of electrical circuit diagrams for 110-330 kV shows that up to four submarines are connected to node substations; The greater number of lines is, as a rule, an inheritance of an unceramed development of the edge, which does not allow for the choice of configuration or the accumulation of spores at the point of the edge of the HV CPU, which can be seen. Schemes for attaching a PS to a boundary, the permissible number of intermediate substations between two CPUs is selected depending on the importance and type of cooperating substations, the length of the boundary section, as seen The advantages of this section and the need to preserve the transit of tension. For certain groups of livestock (traction substations, pumping and compressor stations of main pipelines, naphtha production facilities in Zakhidny Siberia, most places) food is regulated by the authorities and regulatory documents. Recommendations for schemes for acquiring substation for typical groups of live-in residents are given below (sections 4.5–4.9). For the design of low-power substation projects, the development diagrams of power systems and electrical lines are primarily determined by: the location of the substation, the electrical distribution during the expansion periods, the voltage of the switchgear, the strength and power of the transformers, brilliance, direct tension of the line behind the tension, type and tension of the KU, rozrahunkovi values ​​of short circuit flows; recommendations for the main electrical connection diagram. The main benefits of the main electrical connection circuits: the circuit is responsible for ensuring the reliable supply of equipment in normal, repair and post-emergency modes, up to the category of importance for the reliability of electrical supply with the clarity and availability of independent reserve life resources; the scheme is responsible for ensuring the reliability of the transit of tension through the PS in normal, repair and post-emergency modes, similar to the value for the considered section of the fence; The scheme is designed to be simple, straightforward, economical and to ensure the possibility of updating the provision of food for residents in the event of an emergency using automatic means without handing over to personnel; the scheme may allow for the gradual development of RU with the transition from one stage to another without significant work with reconstruction and a break in the food supply; the number of simultaneous circuits that need to be used within one switchgear must be no more than two if the line is damaged and no more than four if the transformer is damaged. One of the most important principles is to ensure maximum reliability and minimum waste, and the unification of constructive solutions to the PS. The greatest effect can be achieved by unifying the PS of mass stagnation, which includes elements of the distribution network of energy systems. A necessary consideration for this is the typification of the basic electrical connection circuits, which signify technical solutions during the design and development of the substation. The standard schemes were approved by VAT "FGC EES" on December 20, 2007. (STO 5694700729.240.30.010-2008). The main electrical connection diagram of the substation is selected from a variety of typical switchgear circuits of 35-750 kV, which are widely used during design. Inputs from standard schemes are allowed subject to technical and economical conditions and conditions using hardening stations. In the remaining edition, the number of standard schemes has been significantly increased (from 14 to 20); Together with this date, 11 schemes have been seen that are recommended in the future. It should be noted that the promotion of low-level new schemes seems to be insufficiently motivated, as long as the principles of incentive measures are violated. For 8 installations of typical switchgear circuits 35-750 kV, and table. 4.4 - outline of the diagrams and spheres of their stagnation. Typical switchgear circuits are indicated by two numbers that indicate the voltage connections and circuit number (for example, 110-5N, 330-7 etc.). The numbers of the schemes have not been changed since the first edition of the standard schemes; Then some schemes were excluded from the number of standard ones.


During the period of the rise of electrical lines at a high rate, at the stage of “widespread electrification” (1960–1985), at 110 kV substations (often - 35 and 220 kV) with simplified circuits at HV as switching devices became widespread nyya waterproof and short-locking. The simplicity of the design and their apparent low cost, equaled with chemicals, made it possible to ensure the mass availability of PS in a short term. At the same time, these devices suffer from numerous design defects and operational deficiencies. The main few schemes with water-reinforcers and short-circuiters are those that individually create a short-circuit to connect a damaged section of the line in a non-flowing pause with the help of a water-reinforcer, which sharply increases the outer damage to the greatest extent. important minds of robots and vimikachs on sumizhnyh PSs. Therefore, at this time, the replacement of water pumps and short circuits on new substations is suspended, and during the reconstruction of existing substations, the stench must be replaced by vimikacs. Up to the numbers of standard circuits, in which hydraulic and short circuits are replaced with chemicals, add the index “H” (3H, 4H, 5H, 5AN). For RU VN, which are characterized by a smaller number of additives, as a rule, simpler schemes are used: without chemicals or with the number of chemicals one and less on the skin. For LV LV, use circuits with bus systems and with a number of outputs greater than one (up to 1.5) per connection. Table 4.4

Continued table 4.4
Continued table 4.4
Completed table 4.4


Block circuits 1, 3Н are, as a rule, the first stage of a double-transformer substation with an end circuit “double block without jumper”. Scheme 1 is stuck in the minds of a contaminated atmosphere, where it is entirely necessary to install a minimum of switching equipment, or for a 330 kV substation, which requires two short submarines. The double 3H circuit is replacing the 4H circuit in the minds of the enclosed Maidan. Local circuits 5, 5N and 5AN are widely used in the range of 110-220 kV. At the first stage, in connection with the circuit diagrams, a diagram of an enlarged block (two transformers and one submarine) or the installation of one transformer is possible; In many cases, there is a need for a number of chemicals. Scheme 6 has been reintroduced in the new edition of standard schemes and, in essence, is one of the options for the first stage. Schemes of rich cutters. Scheme 7 is installed at a voltage of 220 kV with the impossibility of vicorising circuits 5N or 5AN, and at a voltage of 330-750 kV for all substations connected to a minimum of two submarines. At a voltage of 110 kV there is little vicorization. At the first stage, with one AT, three vimics are installed. Scheme 8 (six-knot) is included in the remaining edition of the diagram replacing the expanded chotirikutnik. As a result of the government's scheme, there are 8 shortcomings (rupture of the boundary when repairing any device with automatic connection of one of the units) there is no practical stagnation. For 110-220 kV substations, preference is given to circuits with one bus system, and for 330 kV substation - to “transformer - busbar” or one-and-a-half bus schemes. Schemes with one or two busbar systems are designed for HV switchgear of substations 35-220 kV and LV switchgear (PN) substations of 330–750 kV. Scheme 9 is usually used on the MV and PN side of 110-330 kV substation. Scheme 110-12 is installed on the HV side of node substations in a 110 kV line (usually 4 VL), schemes 110-12 and 220*12 - on the MV side of substation 220 (330) /110/ LV kV and 500/110/N kV. In order to stop using circuit 12 and replace it with circuit 13, more than one radial PL is added to the skin section of the PS tires. However, as follows from paragraph 4.2, saving radial submarines over the last three hours is small. When considering the galusi of the stagnation of circuits 12–14 traces, they are covered with “Galny technical aids to the 330–750 kV substations of the new generation” (BAT “FSK IES”, 2004), therefore for 220 kV switchgear single sectional bus systems, suspended and bypass bus systems are more likely to fail with special lining, protection, or insufficiently reliable or non-redundant electrical circuits. The basis of a rational 110-220 kV distribution network is a vikoristan of closed or sub-unit radial configurations (div. p. 4.2), the main scheme that is recommended for 110-220 kV MV switchgear is a single sectional bus system (scheme 9). In these minds, the inclusion of up to the number of recommended new circuits with one bus system - with attached transformers through a plug with two circuit breakers or “supplementary” PLs through a one-and-a-half strap (schemes 9N, 9AN and 12N) - seems unmotivated, and minds of their stagnation - unimportant: doctors By selecting the voltage of transformers to ensure the life of constant pressure when they are connected (section 5.3.12), it is impossible to identify “shifts in power”, for which it is necessary to completely duplicate the MV voltage in the transformers; in a closed, separate range with changing modes and the roll of adjacent plots, it is impossible to see more and fewer subordinate lines. Transformer circuits - buses and repeaters for acquisition 15–17 to be installed for RU HV substations 330–750 kV and RU SN PS 750/330, 500/220 and 1150/500 kV. Schemes 16-17 for a voltage of 220-500 kV are usually installed on the MV side. With several ATs (schemes 15, 16) or more than six lines (schemes 16, 17), as well as the stability of the system, the need for bus sectioning is verified. RU circuits 10 (6) kV is induced at 9. A circuit with one sectional busbar system (9, 1) is interconnected with two transformers with non-split PN windings, a circuit with two sectional busbar systems (9, 2 ) - with two transformers with a split PN winding or double reactors, a circuit with three or more single sectional bus systems (9, 3 ) - with two transformers with a split PN winding and double reactors. With proper priming, the installation of another sectional pump is allowed. The synchronous compensator is attached directly to the PN AT winding behind the block diagram (9, 4) with start-up through the reactor.

Batteries of static capacitors, when connected to the PN, are connected to the RU section of the PN. For a 20 kV switchgear - a voltage with a certain increase in width (division 4.1) - it is generally recommended to use a circuit with one sectional bus system (diagram 9), for adjacent connections with dead-end single-transformer substations - a block diagram (3H). For substation with HV 35-220 kV, factory production of block complete transformer substation (KTP) – KTPB (section 5.8) has been mastered. At 10 induced circuits are produced by the KTPB 110 kV plant, and they follow simple circuits with circuit breakers at HV.

KTPB 220 kV circuits with simple circuits on the HV side are pointed to 11. The maximum strength of the 110 kV substation that goes to the substation from the HV 220 kV is pointed lower:

a) See the circuits and their meanings

The main electrical connection diagram of a power station (substations) is the totality of the main electrical installation (generators, transformers, lines), busbars, commutation and other primary equipment from the entire circuit they are naturally connected between them.

The choice of the main circuit is the initial step during the design of the electrical part of the power plant (substation), since it indicates the final storage of elements and connections between them. The main circuit is selected and is the output for arranging the electrical connection circuit diagrams, power consumption circuits, secondary connection circuits, wiring diagrams, etc.

On the chair, the main circuits are displayed in a single-line diagram when all installation elements are turned off. In some cases, it is allowed to display the circuit elements in their operating position.

All elements of the circuit and the connections between them are displayed in accordance with the standards of the unified system of design documentation (USD).

In case of operation, it is necessary to use the main circuit using simpler operating circuits, which require no basic installation. The skin change staff fills in the operational scheme and makes necessary changes before it in order to meet the conditions of the medical workers and disconnectors who are present at the hour of the skin change.

p align="justify"> When designing an electrical installation, before developing the main circuit, a block diagram of the type of electrical energy (power) is formed, which shows the main functional parts of the electrical installation (distribution devices, transformers, generators) and connections between them. Block diagrams serve for further development of more detailed and important schemes, as well as for basic understanding of the operation of the electrical installation.

b) Basic instructions for basic electrical installation diagrams

When choosing electrical installation diagrams, the following factors are to be considered:

The role of the power plant or substation is important for the energy system. Power plants that operate in parallel in the energy system must compete for their purposes. Some of them, the basic ones, carry mainly electric power, while others, peaks, operate differently at the hour of maximum power, while others carry electrical power, which is indicated by thermal generators (CHC). The importance of power plants means the importance of maintaining various electrical connection circuits in order to ensure that the same ones are used.

Substations may be used for the purpose of supplying food to several residents of a large region, for connecting parts of the power system and different power systems. The role of the substation is determined by its circuit;

the position of the power station or substation in the power system, circuits and voltages of adjacent circuits. The high-voltage buses of power plants and substations can be node points of the power system, connecting to the parallel operation of several power plants. In this case, power flows through the buses from one part of the energy system to another - power transit. When choosing schemes for such electrical installations, we are first aware of the need to save the transit of power.

Substations can be dead-end, pass-through, or feeder; The circuits of such substations will have different voltages, with the same number of transformers remaining at the same level of difficulty.

Schemes of 6-10 kV subdivisions are included in the electrical supply diagrams of the companions: power supply on single or parallel lines, the availability of reserve ones should be introduced in the companions as well;

In terms of reliability, electrical power supply can be divided into three categories.

Category I electrical appliances - electrical appliances, interruptions in power supply that can cause problems in people’s lives, significant disruption to the people’s state, damage to expensive basic equipment, massive defects in products, disruption of the technological process, disruption of function recognition of particularly important elements of communal dominion.

In this warehouse of category I electrical receivers there is a special group of electrical receivers, uninterrupted operation of which is necessary for trouble-free operation in order to avoid threats to the lives of people, victims, and... kojennyu dear possession.

For electrical supply of a special group of category I electrical receivers, an additional supply of a third independent power source is supplied. Independent life-saving devices can be local power stations, power stations of energy systems, special uninterruptible life units, rechargeable batteries, etc.

Electrical acceptors of category II - electrical acceptors, interruptions in power supply can lead to massive shortages of products, massive downtime of workers, industrial transport mechanisms, significant disruption of normal activity hundreds of small and rural bastards. These electrical devices are recommended to provide backup power to two independent motors, which mutually reserve one of each other; they are allowed to have a break for an hour, which is necessary to switch on the reserve power for the activities of casual personnel or a visiting operational team.

It is allowed to operate electrical appliances of category II on one damaged line, which ensures the possibility of carrying out emergency repairs on that line per hour no more than 1 additional time. It is allowed to live along one cable line, which consists of at least two cables connected to one sleeping device. Due to the presence of a centralized reserve of transformers and the possibility of replacing a damaged transformer in an hour of no more than 1 hour, one transformer is allowed to live.

Electrical receivers of category III - all other electrical appliances that do not fit into the designated category I and II.

For these electrical devices, the power supply can be reduced to one power supply unit in order to interrupt the power supply, which is necessary for repairing or replacing a damaged element of the power supply system, without exceeding one additional charge.

The prospect of expansion and intermediate stages of development of the power plant, substation and adjacent boundary plots. The scheme and layout of the separate structure must be chosen to accommodate a possible increase in the amount of power due to the development of the energy system. While the daily life of large power plants is carried out in stages, when choosing electrical installation schemes, a number of units and lines are taken into account that are introduced before the first, second, third stages and during the residual development of them.

To select a substation circuit, it is important to consider the strength of the high and medium voltage line, the level of its type, and then at various stages of the development of the power system, the substation circuit can be different.

The gradual development of the distribution scheme of the power plant or substation does not have to be accompanied by major reworkings. This may be less important if you choose a scheme to ensure the prospects for its development.

When choosing electrical installation diagrams, the permissible level of short-circuit currents is ensured. If necessary, power supply sections are installed, electrical installations are carried out on independent parts, and special devices are installed to separate the struts.

From the complex set of minds that go into choosing the main electrical installation circuits, you can see the main benefits of the circuits:

reliability of electricity supply for residents; Sustainability before repair work is carried out; operational flexibility of electrical circuits; economical efficiency.

Reliability - the power of the electrical installation, electrical circuit and energy system to ensure uninterrupted power supply at normal power levels. Existing equipment in any part of the circuit may not disrupt power supply, the supply of electricity to the power system, or the transit of power through the buses. The reliability of the circuits depends on the nature (category) of the residents, which determines the supply of the electrical installation.

Reliability can be assessed by the frequency and severity of power failures in the existing emergency reserves, which are necessary to ensure a given level of accident-free operation of the power system and adjacent units.

The integrity of the electrical installation before repairs is determined by the possibility of carrying out repairs without damaging or interconnecting the electrical supply. Create circuits in which, for repairing a device, it is necessary to turn on the data for the entire hour of repair; in other circuits, it is necessary to turn on several other devices for an hour to create special repair circuits; For the third, the repair of the electrical system can be carried out without damaging the electrical supply within a short period of time. Thus, the suitability for carrying out repairs of circuits can be assessed based on the frequency and average difficulty of connecting companions and life resources for repairs of equipment.

The operational flexibility of electrical circuits is determined by their adherence to the creation of necessary operating modes and the implementation of operational interconnections.

The greatest operational flexibility of the circuit is ensured when its operational switching is generated by circuit breakers and other switching devices with a remote drive. If the operation is carried out remotely, and even more so using automation, then the elimination of the emergency situation will be significantly accelerated.

Operational flexibility is assessed by the strength, complexity and complexity of operational changes.

The economical effectiveness of the schemes is assessed by the costs incurred, which include costs for the installation - capital investment, operation and possible damage due to power failure.

c) Block diagrams of power plants and substations

The structural electrical diagram is located in the storage warehouse (the number of generators, transformers), the division of generators and the distribution between separate devices (RU) of different voltages and the connection between these RU.

In Fig. 1 shows the block diagram of the TPP. If the thermal power plant is located near the constant power supply U = 6 ÷ 10 kV, a separate generator voltage device (GRU) is required. The number of generators that will be supplied to the GRU must lie at a voltage of 6-10 kV. In Fig. 1, and two generators are connected to the GRU, and one, usually a heavier one, is connected to the high-voltage distribution device (HV RU). Lines 110 - 220 kV, connected to the distribution center to make connections with the power system.

Since energy-intensive production plants are transferred near the thermal power plant, their storage can be carried out at a submarine of 35 - 110 kV. At this connection, a separate medium-voltage device (RU SN) is transferred to the TPP (Fig. 1 b). Connections between switchgear of different voltages are made using triwinding transformers or autotransformers.

With a slight increase in voltage (6-10 kV), the generators are completely connected to the moving transformers without cross-coupling on the generator voltage, which changes the short-circuit flow and allows the replacement of the expensive GRU to be replaced by a complete switchgear for the connection spozhivachiv 6-10 kV (Fig. 1 , V). Heavy-duty power units of 100 – 250 MW are connected to the HV switchgear without soldering for living quarters. The constant pressure of the TEC is drawing up the block diagram.

Malyunok 1. Structural diagrams of TPP

Malyunok 2. Structural diagrams of KES, GES, AES

Malyunok 3. Block diagrams of substations

In Fig. 2 displays of block diagrams of power plants with an important distribution of electrical energy on the driven voltage (KES, GES, AES). The presence of people living near such power plants makes it possible to suspect the GRU. All generators are connected in blocks with transformers that move them. The parallel operation of the blocks operates at high voltage, where a separate device is transferred (Fig. 2, a).

If electricity is supplied to the main and medium voltage, the connection between the switchgear is made by an autotransformer connection (Fig. 2, b) or an autotransformer installed at the block with the generator (Fig. 2, c).

In Fig. Figure 3 shows the block diagrams of the substations. At a substation with double-winding transformers (Fig. 3, a), the electricity from the power system reaches the HV switchgear, then it is transformed and distributed among the workers at the PN switchgear. At the node substations there are connections between adjacent parts of the power system and the lives of residents (Fig. 3, b). It is possible to arrange a substation with two medium voltage switchgears, HV switchgear and PN switchgear. At such substations, two autotransformers and two transformers are installed (Fig. 3, c).

The choice of both other structural diagrams of power plants and substations is carried out on the basis of a technical and economical comparison of two or three options.

ELECTRICAL DIAGRAMS ON THE 6-10 kV SIDE

a) Scheme with one busbar system

The simplest electrical installation circuit on the 6-10 kV side is a circuit with one non-sectional busbar system (Fig. 4 a).

The scheme is simple and straightforward. In Dzherela, the 6-10 kV lines are connected to the busbars with the help of distributors and disconnectors. For the skin, you need one device that can be used to switch the skin on and off in normal and emergency modes; If you need to turn off the W1 line, just turn on the Q1 line. If switch Q1 is being repaired, after switching it off, turn on the connectors: first line QS1, and then bus QS 2.

Thus, operations with disconnectors are only necessary when the connection is made with the method of ensuring a safe and secure operation. Due to the uniformity and simplicity of the operation with the disconnectors, the accident rate due to incorrect actions with them by the staff is small, so it is important to compare the schemes that are seen.

Malyunok 4. Schemes with one system of busbars, non-sectional (a) and sectioned by vimikachami (b)

The scheme with one bus system allows for the installation of complete switchgear units (SGD), which reduces the installation time, allows for widespread installation of mechanization and changes in the time of installation of the electrical installation.

Despite its advantages, the scheme with one non-sectional bus system has a low number of shortcomings. To repair busbars and busbar connectors of any kind, it is necessary to completely remove the voltage from the busbars and turn on the life supply. This is to interrupt the power supply to all people during repairs.

In case of a short circuit on the line, for example, at point K1 (Fig. 4, a), the secondary switch (Q4) will be switched on, and all other connected devices will be lost in the operation; However, when this circuit is removed, the circuit breakers of the Q5, Q6 life cycles become immobilized, as a result of which the collecting tires are deprived of tension. A short circuit on the busbars (point K2) also triggers the switching on of the life energizers, so that the electricity supply to the occupants is interrupted. The designated shortfalls are often covered with a path under the busbars in the section, the number of which indicates the number of life cycles.

In Fig. 4b shows a diagram with one busbar system. sectioned by a vimikachem. The circuit saves all the advantages of circuits with a single bus system; In addition, an accident on assembled tires can result in the shutdown of less than one vehicle and half of the passengers; another section and all the accrual before it will be forfeited from the robot.

The advantages of the circuit are simplicity, simplicity, cost-effectiveness, and high reliability, which can be confirmed by connecting the main step-down substation (GPS) to the electrical installation buses with two lines W3, W4 (Fig. 4). ,b). If one line is faulty (short circuit at point K2), switches Q2, Q3 are switched on and QB2 is automatically switched on, which is the life of the first section of the GPP line W4.

In the event of a short circuit on the busbars at point K1, switches QB1, Q6, Q3 are switched on and QB2 is automatically switched on. When one device is turned on, the life force that was lost in the work takes over.

Thus, the provision of the GPP in these emergency modes is not compromised in any way by the presence of two life lines connected to different sections of the station, the responsibility for which is insured on the outside (100% reserve at least). Due to the presence of such a reserve along the boundary, a scheme with one sectional bus system can be recommended for certain companions.

However, the scheme has a number of shortcomings.

If one section is damaged and undergoes further repairs, all the companions who live normally in both sections are lost without reserve, and the companions not reserved in the meantime are switched on for the entire hour of repair. In this mode, the life cycle connected to the section being repaired is switched off for the entire hour of repair.

The remaining part can be removed by adding up to two sections at a time, or using the folding design of a separate structure and a larger number of sections (two sections on the skin).

The above diagram (Fig. 4 b) shows the sectional circuit breaker QB1 in the normal switching mode. This mode should be adopted in power plants to ensure parallel operation of generators. At the substations, the sectional circuit breaker in normal mode is connected to the circuit of short-circuit circuits.

A scheme with one busbar system is widely used for substations with a voltage of 6-10 kV and to maintain the power needs of the station, where it is possible to overcome its transfers, especially the permanent stagnation of switchgear.

At the generator voltage of power plants, which supply most of the electricity to nearby workers, circuits can be installed with one bus system connected in a ring (Fig. 5). The busbars are divided into sections for the number of generators. The sections interconnect with each other via sectional reactors QB and sectional reactors LRB, which serve to interconnect the short-circuit flow on the busbars. Lines 6 -10 kV are connected to the switchgear busbars, which maintain life through group double reactors LR1, LR2, LR3 from the separate sections of the head distribution unit. A number of group reactors are located in a number of lines and 6-10 kV distribution lines. There is a low probability of accidents at the reactor itself and the busbar from the reactor to the main busbars and to the switchgear assemblies of the group reactor operates without a liquid pump, only the power supply is transferred to the repair shops and reactor. For lines at drops, the switchgear middles should be stagnated.

Malyunok 5. Scheme with one system of busbars connected at the ring

The skin circuit of the double reactor can be rated at 600 to 3000 A, so that several lines of 6 kV voltage can be connected to the skin circuit. In the diagram (Fig. 5) eighteen lines are connected through three group reactors; In this way, the amount of power supplied to the head busbars is changed equally from the scheme without group reactors with 15 sections, which significantly increases the reliability of the operation of the head busbars of the power plant, reducing costs increase in RU for the change in the number of reactors and change the installation time due to the installation of complete terminals for connecting lines 6-10 kV.

The life of the companions is carried out at least in two lines from different double reactors, which ensures the reliability of electrical supply.

Since the generator voltage buses are divided into three or four sections and are not connected in a ring, there is a need to verify the voltage between the sections when one generator is connected. So, when the generator G1 is turned on, the first section is required to live from the generators G2 and G3, which were lost in the operation, in which the stream from G2 passes through the reactor LRB1, and the stream from G3 passes through two reactors - LRB2 and LRB1. Due to the loss of voltage in the reactors, the voltage level in the sections will be different: the highest in section V3 and the lowest in section B1. To increase the voltage in section B1, it is necessary to shunt the LRB1 reactor, for which purpose in the transmission circuit there is a QSB1 connector that shunts. In this mode, the other shunt switch does not turn on, since it leads to parallel operation of generators G2 and G3 without a reactor between them, which is unacceptable due to the connection of a short circuit.

The order of operation of shunt switches is as follows: turn on the sectional switch QB, turn off the shunt switch QSB, turn off the sectional switch QB.

The more sections there are in a power plant, the more important it is to maintain the current level of voltage, so for three or more sections the busbar is connected at the ring. In the diagram in Fig. 5, the first section can be connected to the third section with a reactor and reactor, which creates a ring of busbars. Normally, all sectional reactors and generators operate in parallel. In the event of a short circuit in one section, the generator of this section and two sectional circuit breakers are switched on, but the parallel operation of other generators is not disrupted.

When one generator is connected to the same sections, the voltage is removed from both sides, which creates a smaller difference in voltage across the sections and allows you to select sectional reactors for a smaller flow, lower in the circuit closed bus system.

In the ring circuit, the nominal flow of sectional reactors is approximately equal to 50 - 60% of the nominal flow of the generator, and their support - 8-10%.

b) Scheme of two busbar systems

With regard to the specifics of electrical receivers (I, II categories), their electrical supply circuits (as long as there is a reserve in case of emergency), as well as a large number of busbars for the main distribution unit of the TPP during technical An economical lining can be used to transfer the circuit from two busbar systems (Fig. 6), each leather element is connected through the fork of two bus connectors, which allows the robot to operate on either one or another bus system.

Malyunok 6. Scheme h two busbar systems

In Fig. Figure 6 shows the diagram in a working state: generators G1 and G2 are connected to the first busbar system A1, which separates the life of group reactors and transformers and connections T1 and T2. The operating bus system is sectioned by both the QB and the LRB reactor, the same as in the single bus system design. The other bus system A2 is a backup one, the voltage on it is normal. Both bus systems can be connected to each other via circuit breakers QA1 and QA2 as in normal connection mode.

Another mode of operation of this circuit is possible if both bus systems are under voltage and all inputs are distributed evenly between them. This mode, called robotic operation with fixed attachments of the Lantzugs, causes the tires to stagnate under increased tension.

A scheme with two bus systems allows you to carry out repairs on one bus system, saving all the equipment needed for the robot. Thus, when repairing one section of the working bus system A1, the attached one must be transferred to the backup bus system A2, for which the following operations are carried out:

turn on the tire pump QA2 and remove the operating spring from its drive;

check that the QA2 position is turned on;

connect to the A2 bus system the outlets of all devices that are being transferred;

connect the A1 bus system to all power outlets, except the QA2 outlets and the voltage transformer;

the live voltage of the relay control system, automation and control devices is interrupted to the voltage transformer of the A2 bus system;

check the ammeter for the presence of voltage on QA2;

Apply operating fluid to the drive and turn on QA2;

Carry out preparations before repairing the A1 tire section.

In the event of a short circuit in the first section of the operating bus system A1, the generator G1, the sectional generator QB and the coupling transformer T1 are switched on.

To update the work of co-workers in this type of situation, it is necessary to cancel the following:

turn on all devices that are not connected by the relay protection (dead line devices);

connect all outlets to the damaged section;

close the connectors of all connections of the first section to the backup bus system;

turn on the transformer connection T1, supplying voltage to the backup bus system to check its validity;

inform your family members;

turn on the G1 generator and turn on the generator after synchronization;

turn on the signals of all lines that are turned on.

With this scheme it is possible to use a tire pump to replace a tire pump of any kind.

The scheme that can be seen is very good and reliable. To a small extent, it is necessary to introduce a large number of disconnectors, insulators, flux-conducting materials and chemicals, the folding design of the subdivision, leading to an increase in capital expenses for the GRU sporudzhenya. The only drawback is the use of equipment as operational equipment. The great number of operations performed by the sockets and the complex blocking between the sockets and the sockets lead to the possibility of a smooth connection to the flow of the sockets. The likelihood of accidents due to improper operation of maintenance personnel is greater in schemes with two bus systems than in schemes with one bus system.

A scheme with two bus systems may be installed at the thermal power station, which will be expanded, on which the same scheme was previously used.

ELECTRICAL DIAGRAMS ON THE 35 kV SIDE

a) Simplified switchgear circuits

With a small number of inputs for 35 - 220 kV, simpler circuits are used, which include daily busbars, the number of components is reduced. In such circuits, high voltage circuits are not transmitted. Simplified circuits allow you to change the consumption of electrical installations, waste materials, reduce the wear of the sub-unit, and speed up its installation. Such schemes have generated the greatest expansion at substations.

One of the simpler circuits is the transformer block circuit - line (Fig. 7, a). In block diagrams, electrical installation elements are sequentially connected without cross connections to other blocks.

Malyunok 7. Simple circuits on the VN boat:

a – transformer block – line with HV circuit; b - transformer-line block with branch; c - two blocks with hydraulic bridges and a non-automatic jumper; g - town with Vimikachi

The circuit has a transformer connected to line W and Q2. In case of a line failure, the Q1 switch is switched on at the end of the line (at the district substation) and Q2 on the side of the HV transformer; in case of a short circuit in the transformer, Q2 and Q3 are switched on. In blocks, the generator - transformer - power supply line Q2 is not installed, if there is a fault in the block, it is connected to the generator power supply line Q3 and at the district substation Q1.

In transformer-line blocks at substations (Fig. 7,b), QR connectors and QN short-circuit breakers are installed on the side of the high voltage. To connect the transformer in normal mode, it is enough to turn on the voltage supply than Q2 on the 6-10 kV side, and then turn on the magnetization source of the QR transformer. The permissibility of the remaining operation depends on the strength of the transformer and its rated voltage.

If there is a fault in the transformer, the relay switch turns on the Q2 switch and sends a pulse to switch on the Q1 switch at the power system substation. The high-voltage pulse can be transmitted by a specially laid cable, telephone communication lines or a high-frequency channel of a high-voltage line. Having received the TV switching pulse (TO), the Q1 switch is turned on, after which the QR is automatically turned on. The transit line to which the transformer is connected must lose voltage, so after QR is connected, the Q1 switch is automatically switched on. The pause in the automatic reclosure (AR) circuit may be adjusted to the hour of QR connection, otherwise the line will be turned on unless the transformer is faulty.

The Q1 voltage can be secured without transmitting a TV pulse. For this purpose, on the HV side of the installations there is a short circuit QN. The transformer protection, in fact, supplies an impulse to the QN drive, which, when turned on, creates a short circuit. Relay protection of line W1 is activated and activated by Q1. The need to install a short circuiter arises from the fact that the relay protection of line W1 at the power system substation may appear insensitive until a fault occurs in the middle of the transformer. However, the shutdown of short-circuits creates important problems for the circuit breaker at the live end of the line (Q1), so which circuit breaker must be switched on in case of a short circuit.

The main advantage of the circuits (Fig. 7, b) is cost-effectiveness, which has led to the widespread use of such circuits for single-transformer substations that are connected to blind connections to the transit line.

The reliability of the work of the considered circuits lies in the clarity and reliability of the work of the short-circuiters and short-circuiters, which is why it is necessary to completely replace open-air short-circuiters with SF6 gas. For the same reasons, the replacement of a clerk may be due to the installation of QW.

On the paranda -former Pidstanziyi 35-220 kV, the circuit of the Blokv - transformer - Linіya, yaki for bilshi gnuchkosti z'dnani is non -automatic worships of the cowl rose, QS4 (Fig. 7, c). In normal mode, one of the jumper connectors may be short-circuited. If nothing can be done, then in the event of a short circuit of any line (W1 or W2), the offending lines are switched on by a relay switch, destroying the power supply of all substations connected to these lines.

Transformer connections (operational and emergency) are configured in the same way as in the single block circuit (Fig. 7, b). The jumper between the two connectors is victorious when the lines are connected.

If line W1 is permanently damaged, Q1, Q3 are switched on, and the ATS operating at 6-10 kV switches on the sectional switch QB, ensuring the provision of food from T2. When the line is put out for repairs, then the line switch QS1 is switched on by the substation personnel or the operational visit team, the switch switch is turned on at the jumper and transformer T1 is placed under the control of the switch and on the side of the PN (Q3) on the further side of the sectional vimikach. This scheme has better food T1 from line W2 during the repair of line W1 (or the restoration of T2 from line W1).

At 220 kV substations, connectors are installed in front of the QR1 and QR2 disconnectors.

At the BN power station, at the first stage of its development, it is possible to stagnate the area circuit with vimikachami (Fig. 7, d) with the possibility of moving forward to the circuit with busbars.

In the circuit for four, three vimics Q1, Q2, Q3 are installed (Fig. 7, d). Normally, Q3 switches between two lines W1 and W2 (at the place) of inclusions. If the W1 line is damaged, the Q1 switch is switched on, the T1 and T2 transformers are lost from the robot, and connections to the power system are established along the W2 line. In case of damage to the transformer T1 The 6-10 kV switches Q4 and the Q1 switches and Q3 are connected. In this case, line W1 appeared to be switched on, although there are no regular faults on it, and there are not many circuit diagrams. It is important to note that emergency shutdown of transformers rarely occurs, such a small number of circuits can be tolerated, especially after connecting Q1 and Q3 and, if necessary, repairing a damaged transformer 'Ednuvach QS1 and turn on Q1, Q3, updating the work of line W1.

To save the work of both lines when revising any circuit breaker (Q1, Q2, Q3), an additional jumper is transferred from two connectors QS3, QS4. Normally, one connector QS3 jumper is switched off, all switches are switched on. To check the Q1 pump, turn on QS3 first, then turn on Q1 and the connectors on either side of the pump. As a result, transformers and offending lines were lost in operation. If one line becomes short-circuited in this mode, then Q2 will turn on, i.e. the offending line will be deprived of voltage.

To check the jumper Q3, also turn on the jumper first, then turn on Q3. This mode has the same shortcomings: when one line is short-circuited, the offending lines are switched on.

The likelihood of avoiding an accident by inspecting one of the circuits is greater than the greater the risk of repairing the circuit, since the remaining option for developing this circuit at power plants will not stagnate.

On the 35 - 220 kV side of the substation, it is allowed to install the circuits with circuit breakers in the transformer lanterns instead of water-breathers and short circuits, since the installation of the remaining ones behind climate control units is unacceptable.

b) Kilce schemes

In ring schemes (rich circuit schemes), the components connect with each other, forming a ring. A leather element - a line, a transformer - is connected between two adjacent circuits. The simplest ring diagram is the tricutaneous diagram (Fig. 8 a). Line W1 is connected to the circuit by circuits Q1, Q2, line W2 - by circuits Q2, Q3, transformer - by circuits Ql, Q3. The addition of more elements to the basic circuit increases the flexibility and reliability of the robot, while the number of components in the circuit does not seem to exceed the number of additions. The trikutnik scheme has three attachments - three benefits, so the scheme is economical.

In circular schemes, the revision of any chemical source is carried out without interrupting any element. So, when revising the vimikach Q1, turn on the same connectors installed on the side of the vimikach. If the lines and transformer are damaged, they will be lost in the robot, prot

Malyunok 8. Kilcevy schemes

The scheme becomes less reliable due to the ring breaking. If in this mode there will be a short circuit on line W2, the circuits Q2 and Q3 will be switched on, as a result of which the offending lines and the transformer will be deprived of voltage. The Vydklochennya Vykhkhkhkhdtstandsky vidu is such when KZ in the LINIA TO VIMIKACHA: So, in the way, at the KZ on LINI W1 I VIMIKOVI VIMIKACA Q1 vimikachi Q2 I Q3. The likelihood of avoiding damage on the line with the revision of the chemical pump, as it was determined, is more important than the repair of the chemical pump. Increasing the turnaround time and reliability of chemicals, as well as reducing the cost of repairs, will significantly improve the reliability of the circuits.

Ring circuits are more reliable than other circuits, but there is the possibility of testing any kind of circuit during normal operation of circuits. Testing the circuit with this connection does not disrupt the operation of the connected elements and does not cause unnecessary interruptions in the circuit.

In Fig. 8b shows a diagram of the chotirikutnik (square). This scheme is economical (even though it is used), it allows testing and auditing of any device without damaging the operation of its elements. The scheme has high reliability. The connection of all is less reliable, which can happen if the revision of one of the circuits, for example Q1, is damaged, line W2 is damaged, and the circuit of another circuit, Q4, is damaged. In lances, linear outlets are not installed, which lightens the design of the outdoor switchgear. When repairing line W2, switch on the switches Q3, Q4 and the connectors installed near the other lines. The connection to W1, T1 and T2, which was lost in the work, is carried out through contacts Q1, Q2. If T1 is damaged during this period, then the Q2 switch will turn on, the other transformer and the W1 line will be lost from the work, otherwise the transit of pressure will be damaged.

The advantage of all ring circuits is the elimination of disconnectors from repair work. The number of disconnection operations in such schemes is small.

To the few ring circuits, it is necessary to bring together a selection of transformers, reactors and disconnectors installed at the ring, the fragments are stored in the operating mode of the strum circuits, which flows through the devices, changes. For example, when revising Q1 (Fig. 8, b), in Lancusia Q2 the strum doubles in size. The relay guard may also be required to ensure that all possible modes are adjusted before the time when the circuit's chemicals are put into audit.

The chotirikutnik circuit will be installed in the switchgear of 330 kV and higher power plants as one of the stages of circuit development, as well as substations with a voltage of 220 kV and higher.

The scheme of the shestikutnik (Fig. 8, c), which contains all the features of the various schemes, was used to achieve wide stagnation. Vimics Q2 and Q5 are the weakest elements of the circuit, so they can be damaged to connect two lines W1 and W2 or W3 and W4. If these lines undergo tension transit, it is necessary to check whether the stability of the parallel operation of the power system will be damaged.

Finally, it should be noted that the constructive arrangement of the separate devices behind the ring circuits allows you to easily move from the circuits of the tributary to the circuits of the circuit, and then to the circuits of transformer blocks - busbars or to circuits with busbars .

c) Schemes with one operating and bypass bus system

One of the most important benefits of high-pressure schemes is the creation of minds for revision and testing of chemicals without interruption of work. This is clearly demonstrated by a circuit with a bypass bus system (Fig. 9). In normal mode, the AT bypass bus system is without voltage, the QSO connectors that connect the lines and transformers to the bypass bus system are connected. The circuit transmits a bypass circuit QO, which can be connected to any section by splitting two connectors. The sections are arranged parallel to each other. The QO signal can replace any other device, which requires the following operations: turn on the QO bypass device to check the functionality of the bypass bus system, turn on QO, turn on QSO, turn on QO, turn on Q1, Plug in connectors QS1 and QS2.

After the specified operations, the line outputs life through the bypass bus system and the Q0 switch from the first section (9, b). All these operations are carried out without damaging the electrical current along the line, although they are associated with a high degree of interruption.

Due to this saving, the functions of bypass and sectional devices can be connected. On the diagram in Fig. 9 and the terminal of the switch Q0 is a jumper from two sockets QS3 and QS4. In normal mode, this jumper is closed, bypassing the connections to section B2 and also the connections. In this way, sections B1 and B2 are connected to each other

Malyunok 9. Scheme with one working and bypass bus system:

a - a diagram with a mixture of bypass and sections in the transformers; b - mode of replacing the linear pump with a bypass one; c - diagram with bypass and sectional vimics

via QO, QS3, QS4, and the bypass signal downloader changes the functions of the sectional controller. When replacing any line switch bypass, you must turn on the QO, turn on the jumper connector (QS3), and then change the QO accordingly. For the entire hour of repairing the linear pump, the parallel section of the robot is then destroyed. The lances of the transformers in the circuit that can be seen have plugs installed (QW triggers can be installed). If the transformer (for example, T1) is damaged, the W1, W3 and QO switches are switched on. Once QR1 is activated, the controller will turn on automatically, resuming the work of the lines. Such a scheme will require precise automation robots.

Scheme 3 Fig. 9, A It is recommended for HV substations (110 kV) with the number of connections (lines and transformers) up to six inclusive, if the failure of the parallel operation of the line is permissible and the daily prospect of further development. If there is a prospect of expansion of the switchgear, then vimics are installed in the transformers. Circuits with transformer circuits can be installed for voltages of 110 and 220 kV on the HV and MV side of the substations.

In both of the above schemes, the repair of a connection section involves the connections of all lines connected to this section and one transformer, so such schemes can be combined with paired lines or lines that are reserved from other stations, as well as radial ones, but not more than one per section .

At power plants, it is possible to install a circuit with one sectional bus system in Fig. 9, along with additional bypass treatments on the skin section.

d) Scheme with two operating and bypass bus systems

For RU 110 - 220 kV with a large number, a circuit with two working and bypass bus systems with one circuit breaker per lance is installed (Fig. 10, a). As a rule, different bus systems operate in the robot with a fixed fixed distribution of all connections: lines W1, W3, W5 and transformer T1 are connected to the first bus system A1, lines W2, W4, W6 and transformer T1 connected to another A2 bus system, tire changer QA inclusions. This division adds to the reliability of the circuit, since in the event of a short circuit on the buses, the QA bus terminal switches on and only half of the supply voltage is switched on. If there is damage to the tire rack, then the connection that is connected must be transferred to the reference bus system. The interruption of power supply half of the power supply means that the interruption is trivial. The considered diagram is recommended for RU 110 - 220 kV on the HV and MV side of substations with the number of connections being 7-15, as well as at power stations with up to 12 connections.

Malyunok 10. Scheme with two working and bypass bus systems:

a – basic diagram; b, c - scheme options

For RU 110 kV and above all, a few of the following schemes are suitable:

In the event of an emergency, in case of an emergency all the power lines connected to a given bus system are turned on, and if there is one bus system in the robot, all connections are turned on. The elimination of the accident is delayed, because all operations involving the transition from one bus system to another involve disconnectors. Since the vitality of the turbogenerator-transformer blocks is tight, then their start-up after reducing the pressure for an hour more than 30 minutes can take a few years;

Damage to the tire pump is equivalent to a short circuit on both bus systems, so that all connections are connected;

The great number of operations performed by the diverters during inspection and repair of chemical equipment complicates the operation of the reactor plant;

The need to install tire and bypass devices and a large number of disconnectors increases the costs of RU repair.

Greater flexibility and reliability of the circuits can be achieved by sectioning one or both bus systems.

On TES and AES, with a number of 12-16 sections added, one bus system is used; with a larger number of sections, two bus systems are added.

At the substations, one bus system is sectioned at U = 220 kV with a number of inputs of 12-15 or when transformers are installed with a capacity of over 125 MVA; All bus systems 110 - 220 kV are sectioned when the number of connections exceeds 15.

Since the collection tires are sectioned, then to reduce capital costs it is possible to freeze the volumes of QOA tire and bypass devices (Fig. 10, b). In normal mode, the switches QS1, QSO, QS2 are turned on and the bypass switch takes over the role of the bus drive. If it is necessary to repair one vimicach, turn on the QOA vimicach and the QS2 connector and use the bypass vimicach for direct reasons. In circuits with a large number of lines, the number of such intermittents on the river is significant, which leads to complexity of operation, which tends to reduce the number of busbars and bypass circuits.

At the schemes with security tires at the Poskojenni on the tires of the Abo in the KZ in the LINIA, the Vimikacha is frailing 25% of the reception (for the hour of the truck), the prose in the cluser in the sequetic validity of the validity of the validity of the validity of 50% of the time.

For power plants with heavy-duty power units (300 MW or more), the reliability of the circuit can be increased by adding a core or autotransformer connection through a plug from two circuits (Fig. 10, c). In normal mode, these devices perform the functions of a tire unit. If there is a fault on either bus system, the autotransformer is lost from the robot, and the possibility of wasting both bus systems is disabled.

e) Scheme with two bus systems and three-way vimikachami for two lancets

For separate devices of 330 - 750 kV, there is a scheme consisting of two busbar systems and three circuit breakers for two lanyards. As can be seen from Fig. 11, for six you need to add nine vimikacs, so that a “repeater” of vimikac is added to the skin (this is also called another scheme: “one and a half”, or “scheme with 3/2 vimikac for lance”).

Malyunok 11. Scheme with 3/2 vimikach for acquisition

The skin is softened through two treatments. To connect line W1, you must connect switches Q1, Q2 to connect the transformer T1 - Q2, Q3.

In normal mode, all the circuits are high, and the bus systems are under voltage. To inspect any vimicach, turn on the connectors installed on the side of the vimicach. The number of operations required to enter into revision is minimal, since they only serve as a sub-department during repairs, and daily operational alternations eliminate them. The advantage of the schemes is those that, due to the revision of any kind, all the acknowledgment will be deprived of the work. Another advantage of the one-and-a-half scheme is its high reliability, since all the lances will be damaged in operation if the tires are damaged. So, for example, in the event of a short circuit on the first bus system, the circuit breakers Q3, Q6, Q9 are switched on, the buses will be deprived of voltage, otherwise all the power supply will remain in operation. However, when the life of the robot line of all lances is maintained, the current is preserved when both bus systems are connected, in which case the parallel robot on the side of the driven voltage may be damaged.

The scheme allows workers to test chemicals in operating mode without any disconnection operations. Repair of tires, cleaning of insulators, inspection of tire dispensers are carried out without damaging the work of the lancets (a series of tire dispensers are switched on), all lancets are processed in parallel through the tire system that has lost its power spring.

The number of necessary operations of disconnectors for inspection through all devices, disconnectors and busbars is significantly less than in a scheme with two working and bypass busbar systems .

To increase the reliability of circuits, the same elements are added to different bus systems: transformers T1 , TZ and line W2 – to the first bus system, lines W1, W3 – transformer T2 – to the other bus system. With such damage to any element or tire assembly, during one-hour removal of one machine and repair of another connection, no more than one line and one life line are switched on.

So, for example, when repairing Q5, a short circuit on line W1 and in the circuit breaker Q1, circuit breakers Q2, Q4, Q7 are switched on, as a result of which, in addition to the damaged line W1, another element will be connected - T2. After switching off the signal assignments, line W1 can be connected to the line connector and transformer T2 to Q4. Simultaneous emergency connection of two lines or two transformers in the considered circuit is low-voltage.

In the diagram in Fig. 11, three lanyards are attached to the collapsible tires. If there are at least five such lanyards, then it is recommended to separate the tires separately.

A few glimpses of the diagram:

connection of a short-circuit on the line of two circuits, which increases the number of illegal revisions of circuits;

the increased price of the RU design with an unpaired number is added, since one lancet must be added through two means;

Reduced reliability of circuits, since the number of lines corresponds to the number of transformers. In this combination, up to one link from three circuits, two identical elements are added, so it is possible to have an emergency connection of two lines at the same time;

folding of lanzyugs of relay protection;

an increase in the number of drugs in the scheme.

Due to the high reliability and flexibility of the scheme, it is widely used in switchgear of 330 - 750 kV at existing power plants.

At node substations, this scheme will stagnate when more and more people are added. With a smaller quantity, the line is included in the lanyard of three devices, as shown in Fig. 11 and the transformers are connected directly to the busbars, without chemicals that seal the transformer - busbar block.

TEC CIRCUIT MAINS

A) Schemes TEC with generator voltage busbars

At thermal power plants with 63 MW generators, the available electricity, distributed from a 3 - 5 km wind, can supply electricity at the generator voltage. And here at the thermal power plant there is a 6-10 kV main switchgear, that is, with one bus system. The number and strength of generators connected to the GRU are determined on the basis of the project for the supply of electricity to the residents and must be such that with the replacement of one generator that is lost, the food supply of the residents is completely ensured.

Connections to the power system and the type of excess power are made by lines of 110 and 220 kV. If a large number of 110, 220 kV lines are transferred, the thermal power plant combines a switchgear with two operating and bypass bus systems.

As thermal demand increases, turbogenerators with a capacity of 120 MW or more may be installed at thermal power plants. Such turbogenerators are not connected to the generator voltage busbars (6-10 kV), the fragments, first of all, should be sharply increased by the short-circuit current, and in another way, the nominal voltage of these generators is 15.75; 18 kV for the voltage of the separate circuits. Power generators are connected to blocks that operate on 110 – 220 kV busbars.

b) Block diagrams TEC

The increase in the single power of turbogenerators, which has become stagnant at thermal power plants (120, 250 MW), has led to a wide expansion of block diagrams. In the diagram shown in Fig. 12, for those living with 6-10 kV, the food supply is determined by the reactors of the generators G1, G2; The most remote residents live through deep-input substations running 110 kV busbars. The parallel operation of generators accumulates a high voltage, which changes the short-circuit current for 6-10 kV. As with any block diagram, such a scheme provides cost savings, and the absence of a bulky main switch makes it possible to speed up the installation of the electrical part. As soon as the switchgear is installed, there are two sections with AVR on the sectional vim. For greater reliability of electrical supply, the Q1 Q2 circuit breakers are installed in the generator lances. Transformers connections T1, T2 are insured in view of all excess active and reactive voltage and must be provided with an on-load tap-changer.

On the transformers of blocks G3, G4, an on-load tap-changer can be transferred, which makes it possible to ensure a constant voltage level on the 110 kV busbars in the presence of the reserve reactive power of the thermal power station, which operates according to the thermal curve. The presence of on-load tap-changer in these transformers allows changing the voltage supply in MV installations.

With further expansion of the thermal power plant, G5 G6 turbogenerators are installed, connected into blocks. The 220 kV lines of these blocks are connected to a large regional substation. On the 220 kV side of the TEC there are no circuit breakers installed; the line connection must be made at the regional substation. If the sensitivity of the relay protection of the substation is insufficient, before faulting the transformers T5, T6, transmit the transmission of the television pulse (TO) or install short-circuiters and water-receivers. The power supply of the generators is influenced by the pumps Q3, Q4.

The connections between the 110 and 220 kV switchgears are not transferred, which significantly simplifies the 220 kV switchgear circuit. As a matter of fact, it is acceptable that the connection between 110 and 220 kV is installed at the nearest regional substation.

Current thermal power plants (500-1000 MW) are being developed as block type. In generator-transformer units, a generator switch is installed, which increases the reliability of life of the MV and switchgear of high voltage, since this switches off the numerical operations in the switchgear of the MV from the transfer of life from the generator to the reserve transformer of the SN. In the event of a cutaneous interruption, the power unit is switched off using high-voltage circuit breakers. Don’t forget that at TPP the switching on and off of power units fluctuates much more often than at CES and AES.

Malyunok 12. Block diagram of thermal power plant

MAIN SCHEMES KES

a) Vimogi to the schemes of pressing thermal power plants

The load on generators installed at thermal power plants is inevitably increasing. Power units of 500 and 800 MW have been put into operation, units of 1200 MW are being put into operation. It has been established that the intensity of daily CES amounts to several million kilowatts. On the tires of such power plants, there is a connection between several power stations, and there is a flow of power from one part of the power system to another. All this leads to the fact that large CESs play a very important role in the energy system. Before the electrical connection diagrams of the KES there are signs:

1. The main circuit must be selected on the basis of the approved design for the development of the power system, so that the voltage on which electricity is supplied, the voltage diagrams for these voltages, the circuit diagram and the number of lines, so walking, permissible currents of short circuit on moving voltages, in order to maintain stability sectionalization of the boundary, the greatest permissible loss of power on the reserve in the power system and the capacity of the power transmission line.

2. At power plants with power units of 300 MW and more, it is not necessary to connect more than one power unit and one or more which lines, which preserves the stability of the power system. When a sectional or bus-unit pump is damaged, two power units and lines are allowed to be wasted in order to preserve the stability of the power system. If damage is avoided or one power unit is lost while another is being repaired, two power units are allowed to be wasted.

3. It is not the fault of any operator to disrupt the transit through the buses of the power plant, so that more than one line of transit is connected, since the bus consists of two parallel buses.

4. Power units, as a rule, are connected through transformers and devices on the side of the moving voltage.

5. Connections of power transmission lines must be carried out by no more than two circuit breakers, and power units, power transformers - by no more than three skin voltage circuit breakers.

6. Repair of circuit breakers with a voltage of 110 kV and higher may be possible without connecting the power supply.

7. High-voltage switchgear circuits are responsible for transferring the power of sectionalization of the circuit or under the power plant to independently operating parts using the method of interconnecting short circuit flows.

8. When two start-up power supply transformers are connected to this switchgear, the possibility of wasting both transformers in the event of damage or loss of any kind of power supply is turned off.

The remaining selection of schemes should be based on their reliability, which can be assessed mathematically by the quality of the elements. The main scheme can satisfy the regime benefits of the power system and ensure minimal expenditures.

b) Block diagrams: generator - transformer and generator - transformer - line

In a unit with a double-winding transformer, the voltage on the generator voltage is usually daily (Fig. 13 a). The switching on and off of the power unit in normal and emergency modes is determined by Q1 on the side of the moving voltage. Such a power unit is called a monoblock. The connection of the generator with a block transformer and the connection to the transformer MV are connected at current power plants with closed complete jet ducts with separated phases, which ensures high reliability of the robot, practically switching off interphase short circuits in them 'ednannyah. This type of equipment has some commutation equipment between the generator and the transformer that moves, as well as on the connection to the transformer. n. don't overdo it. The presence of a power supply in the galley to the MV makes it necessary to turn off the entire power unit when the MV transformer is damaged (Q1 is switched on, as well as the 6 kV side of the MV transformer and the AGP generator).

Malyunok 13. Generator-transformer power unit circuits:

a, d - blocks with double-winding transformers; b - block with autotransformer; c - information block; g-block with 1200 MW generator

Due to the high reliability of transformer operation and the availability of a necessary power reserve in the power system, this scheme is adopted as a standard for power units with a capacity of 160 MW or more.

In Fig. 13 b shows a diagram of a generator block with an autotransformer. This scheme is based on the presence of two voltage shifts on the CES. When the generator is faulty, the Q3 switch is switched off, and the connections between the two switchgear switchgears are saved. If there is a fault on the busbars with a voltage of 110 - 220 kV or 500 - 750 kV, Q2 or Q1 will be switched on, and the unit will no longer operate on the busbars with a voltage of 500-750 or 110 - 220 kV. Disconnections between the circuit breakers Q1, Q2, Q3 and the autotransformer are necessary for the possibility of removing the circuit breakers for repair while preserving the operation of the unit or the autotransformer.

In some cases, in order to simplify and reduce the cost of the design of the switchgear with a voltage of 330 - 750 kV, two blocks with adjacent transformers are combined under the fire generator Q1 (Fig. 13, c). The Q2, Q3 switches require the inclusion of generators in parallel to the robot and ensure great reliability, since for the maintenance of one generator, the other generator is saved in the robot.

It is important to note that the presence of generator generator defects allows the generator to be started without the need to replace the MV start-up transformer. Who has a problem with the vimikan of the vimikacha generator of life on the bus s.n. supplied through a block transformer and a working transformer s.n. After all start-up operations, the generator is synchronized and connected to Q2 (Q3).

Instead of bulky and expensive generator-voltage generators, generator voltage generators can be installed. In any case, any damage to any energy unit can be brought to the level of vimikacha Q1. After the damaged power unit is separated, the helper enters the work.

The stagnation of common power units is permissible in tight power systems that have sufficient reserve and capacity of intersystem connections, in case of complex layout problems (area is enclosed for the construction of switchgear with a voltage of 500 - 750 kV), and This means saving money on electricity, electricity and cables 'tongues of tension.

A 1200 MW generator, which generates two independent stator windings (six-phase system), is connected to a block with a moving transformer with two PN windings: one connected to the tricube, and the other to the mirror for compensation ZSUVu at 30 ° between the voltage vectors stator windings (Fig. 13, d).

At a number of falls, blocks with a generator generator are installed (Fig. 13, e). The connection and switching on of the generator depends on Q (or on QW), in which case it does not stick

Malyunok 14. CES scheme (8x300 + 1 x 1200) MW

Malyunok 15. CES scheme (6x800) MW

AES CIRCUIT MAINS

A) Special benefits to AES schemes

Like the circuits of other power plants (CHP, KES), the AES circuits must be considered as much as possible before, in terms of reliability, flexibility, ease of use, and cost-effectiveness.

The peculiarities of the technological process of the AES, the high load capacity of the reactor power units, which reaches 1500 MW at current power plants, and the supply of all the load to the power system with lines of 330 - 1150 kV provide a number of special benefits to the AES :

the main circuit of the AES is selected on the basis of the power system interconnection circuits and those sections to which the power plant is connected;

The scheme for connecting the AES to the power system must ensure that normal output modes at all stages of the AES development ensure the newly introduced power of the AES and save the stability of the robots in the power system without the influx of emergency automation during connected to any line that goes to the transformer connection;

In repair modes, as well as in case of failure or relay protection devices, the resistance of the AES must be ensured by the action of emergency automatics for the dismantling of the AES. Insurers can benefit from the fact that at the AES, starting from the first power unit introduced, the connections with the power system operate in no less than three lines.

When choosing the main AES circuit, ensure: the same tension of the units and the same number; voltages that indicate strain on the power system; the magnitude of flows between switchgears of different voltages; KZ streams for skin RU and the need for their exchange; the greatest effort that can be expended in case of any injury; the possibility of connecting one or more power units directly to the switchgear of the nearest regional substation; The voltage, as a rule, is no more than two RU displacement voltages and the possibility of connecting autotransformers between them.

Separate units 330-1150 kV AES are to be installed inclusively and reliably:

damage to any type of generator, either sectional or tire pump, is not at fault, as a rule, leading to the disconnection of more than one reactor unit and such a number of lines as is acceptable for the stability of the power system;

in case of damage to either a sectional or bus-unit pump, as well as in the event of damage or replacement of one pump while repairing the other, it is allowed to connect two reactor units and such a number of lines , which is acceptable due to the mental stability of the energy system;

Line connections, as a rule, require no more than two connections;

connection of transformers that move transformers with. n. that connection is no more than three vimikachami.

Such examples are illustrated by 4/3, 3/2 circuits for connection, block circuits of generator - transformer - line, circuits with one or two rich circuits.

The 110 - 220 kV AES sub-unit is equipped with one or two operating and bypass bus systems. The working bus system is sectioned when the number of connections exceeds 12.

b) Typical AES circuits

Highly qualified healthcare providers are able to work with AES circuits, and design organizations break down the basic electrical circuits of a specific nuclear power plant. Let us look at the most typical AES scheme with channel boiling water reactors of 1500 MW (RBMK-1500) and turbogenerators of 800 MW (Fig. 16). The type of voltage of the AES is available at voltages of 750 and 330 kV. The 330 kV switchgear is being used for the 4/3 circuit for connection. The 750 kV switchgear is located behind the circuit of two interconnected chotyrikutniks with vimikachs at the peremichkas. Generators G3, G4 and G5, G6 create enlarged power units, which allows the economical circuit of the reactor to be established after the third reactor power unit is put into operation. The fourth reactor power unit with generators G7, G8 will be connected to another 750 kV reactor. With further expansion of the nuclear power plant and the installation of the fifth reactor power unit, generators G7, G8 and newly installed G9, G10 will be combined into enlarged power units. The 750 kV lines have a capacity of approximately 2000 MW, so three lines will completely ensure the full capacity of the connected power units while ensuring possible expansion.

Shunt reactors LR1 - LR3 are connected to the line through terminals. The connection between RU 330 and 750 kV consists of a group of three single-phase autotransformers (the installation of a reserve phase is transferred). Reserve transformers s. n. connected RT1 – to the district substation 110 kV; RT2 – up to RU 330 kV; RTZ - up to the average voltage of the autotransformer connection with the possibility of interconnection at the 330 kV switchgear; RT4 - before the PN winding of the autotransformer.

Malyunok 16. Scheme of AES with 1500 MW reactor power units

MAIN DIAGRAMS OF PEDSTATIONS

Zagalnye Vidomosti

The main diagram of the electrical connections of the substation is selected from the arrangement of the electrical circuits of the power system or the electrical supply diagrams of the area.

Based on the method of connection to the junction, all substations can be divided into dead-end, sub-stations, pass-throughs, and nodes.

A dead-end substation is a substation that receives electricity from one electrical installation along one or several parallel lines.

The substation is connected with a blind solder to one or two lines that pass through.

The pass-through substation is switched on until there is one or two lines with two-way or one-way life.

A node substation is a substation to which more than two lines of life lines are connected, which come from two or more electrical installations.

The functions are divided into live and system substations.

The substation diagram is closely related to the characteristics and method of connecting the substation to the extent of life and duty:

ensure the reliability of power supply to the substation and the flow of power through intersystem or main connections in normal and post-emergency modes;

embrace the perspective of development;

allow the possibility of stepwise expansion of the RU of all voltages;

upgrade equipment to emergency automation;

to ensure the possibility of carrying out repair and operational work on adjacent elements of the circuit without connecting the vessel connections.

The number of vimikachs that can be requested at once must be no more than:

two – with a damaged line;

four - with damaged transformers with a voltage of up to 500 kV, three - 750 kV.

Apparently, it is possible to break down the typical circuits of the substations of 6 - 750 kV substations, which are responsible for the design of the substations.

The non-standard head circuit may be lined with a technical and economical design.

Schemes of dead-end and substations

Dead-end single-transformer substations on the 35 -330 kV side are connected to the transformer block circuit - a line without switching equipment or with one connector (Fig. 17 a), since the line is closed from the side of the live end to sensitivity to damage in the transformer. This scheme can also be stuck if the transmission signal is transferred to a TV connection for 330 kV substations with transformers of any strength, and for 110 - 220 kV substations with transformers more than 25 MB A. When cable is inserted into the transformer, The items are not installed.

Defenders on the 35, 110 kV side of power transformers are not victorious. At dead-end and substations up to 110 kV, it is allowed to install circuits with water reinforcers (Fig. 17, b) behind the line: substations installed in cold climate zones, as well as in the especially Ozheleditsky region; how the actions of hydraulic valves and short circuits lead to the synchronization of the synchronous motors in the companion; at substations for transport and oil and gas production; for attaching transformers with a capacity of over 25 MBA; in lancet transformers, connected to lines that can generate OAPV.

In the substation diagram shown in Fig. 17 b on the 110 kV side there is a QS switch installed, a QR distributor and in one phase - a QN short-circuit switch, on the 6-10 kV side - a Q2 switch.

In cases where the above schemes are not recommended, it is not recommended to install a standard circuit with a voltage of 35 - 500 kV (Fig. 17, c).

Malyunok 17. Schemes of transformer blocks - line:

a – without vimikacha VN; b - with VN section; c – h vimikachem VN

Schemes of pass-through substations

If it is necessary to section lines, power of transformers up to 63 MB A, including voltage 35 - 220 kV, local circuits are recommended (Fig. 18). The diagram is shown in Fig. 18 A, stagnant on the 110 kV side with transformer loads up to 25 MB A inclusive. The repair jumper with sockets QS7, QS8 is normally connected by one socket (QS7).

Vimikach Q1 at the switching point, since lines W1, W2 ensure the transit of pressure. It is necessary to turn off the parallel operation of lines W1, W2 in order to ensure that the short circuit circuits are interconnected, and the circuit breaker Q1 is switched off. When the transformer (T1) is faulty, the switch on the side of 6 (10) kV Q4 is switched on, the short-circuit switch QN1 is switched on, the switch Q2 is switched on at the live end of the line W1 and the QR1 switch is switched on, and then the QS switch is switched on 1.

Malyunok 18. Schemes of the town:

a - what is the difference between the peremichtsi and the hydraulic reinforcements in the lancets of transformers; b - with vimikachami in the lancet of the line and a repair jumper on the side of the line

If in the robotic mode it is necessary to renew line W1 in the robot, then the switch at the end of the life line and the switch at Q1 are automatically activated, so that transit along lines W1, W2 is updated. The repair jumper is tested during the revision of the switch Q1, for which QS7, Q1 and QS3, QS4 are turned on. Transit along lines W1, W2 takes place via repair jumpers and transformers. T1, T2 at the robot.

For 220 kV transformers and transformers up to 63 MB A inclusive, to increase reliability, robotic distributors should be replaced with vibration pumps Q1, Q2 (Fig. 18, b).

The repair jumper is open-circuited by QS9. Vimikac Q3 is located at the inclusion point, which will ensure transit through tightness lines W1 and W2. In case of an accident at a transformer T1 6 (10) kV switches and switches Q1 and Q3 are connected on the side. After switching on the QS3 connector, Q1 and Q3 are switched on and transit is resumed. To repair Q1, turn on the repair jumper (QS9 connector), connect Q1 and QS1 connectors to QS2. If in this mode there is an accident in T2, then Q2 and Q3 are switched on and the transformers are lost without life. It is necessary to turn on QS6 and turn on Q3 and Q2, then T1 connects to both lines. This little bit can be removed if the place and repair jumper are replaced in places. In this case, when there is damage in the transformer, one switch on the HV side of the transformer is damaged, the switch in the area is no longer switched on, and the transit of voltage W1, W2 is saved.

Since the system automation project in 220 kV lines transmits OAPV, instead of the above-mentioned circuit, a shortcut circuit is recommended.

The Chotirikutnik circuit is designed with two lines and two transformers if there is a need to section transit lines, with special conditions and voltage of transformers at a voltage of 220 kV 125 MB A and more and any tension at a voltage of 330 - 750 kV.

Schemes of pressure node substations

On the 330 - 750 kV buses of the node substations there are connections between adjacent parts of the power system or connections between two systems, so before the circuits on the HV side, displacements are hung for the sake of reliability. As a rule, in this case, use circuits with a large number of attached lines: ring circuits, 3/2 circuits on a lancet and transformer circuits - buses with attached lines through two circuits (with three or four nіyah) or with the addition of repeat lines (if p' five-six lines).

In Fig. Figure 19 shows a diagram of the powered node substation. On the 330 - 750 kV side there is a bus circuit - an autotransformer. The Lancus skin line has two vimics, autotransformers are connected to busbars without a vimic (disconnectors with a remote drive are installed). In case of injury T1 All switches connected to K1 of the 330-750 kV line are switched on without being damaged. Afterwards T1 From all sides, the QS1 connector is remotely connected, and the circuit on the side of the HV is updated to the inclusion of all devices connected to the first K1 bus system.

Depending on the number of lines 330-750 kV, it is possible to install ring circuits or 3/2 circuits per circuit.

On the side of the medium voltage 110-220 kV of pressure substations, a scheme with one working and one bypass bus system or with two working and one bypass bus system is installed.

When choosing a circuit for NP, we are faced with the supply of the circuit to the short circuit. For this purpose, you can install transformers with shifted values ​​u to, transformers with a split PN winding, or install transformer lancug reactors. In the circuit shown in Fig. 19, on the PN side there are double reactors installed. Synchronous compensators with starting reactors are connected directly to the PN connections of the autotransformers. The addition of heavy-duty GCs to 6-10 kV busbars led to an unacceptable increase in short-circuit currents.

At the autotransformer lances, linear regulating transformers JIPT can be installed on the side of the PN for independent voltage regulation.

Malyunok 19. Scheme of the node substation

Malyunok 1.15. Scheme for knitting chotirikutniks.

Vimikachi at the bridges will focus on economical displays of circuits and complicate the design of the separate structure. Therefore, with a high volume of power supply at a voltage of 330 kV, it is better to combine circuits with the same type of power supply elements.

1.6. Schemes “Napivtorn” and 4/3 (almost three)

The circuits will be installed at a voltage of 330 kV and higher with the number of incoming

there are six or more.

Small picture 1.16 shows a diagram in which the ratio of the number of recipients to the acquisition reaches 1.5 (repeats).

Malyunok 1.16. Second scheme.

A diagram is shown on baby 1.17, which ratio of the number changes -

lei to add 4/3. The principle of incentive schemes is lost by itself, the cost-effectiveness coefficient (1.33) is shorter than one and a half (1.5), but it still stagnates less often.

hoists and significantly increases the cost of outdoor switchgear design. Yakshcho vrahuvati, scho the height of the stan-

When the portals at the 500 kV GRP are set to 27 m, it becomes clear why such a structure rarely gets stuck.

This problem may be caused by the way of vikoristanny vascular connections (r

Figure 1.18), but in this case the hidden dimensions of the GRP will grow.

The width of the core of the 500 kV outdoor switchgear becomes 30 meters, and with this arrangement, the number of cores is subdivided, and the output of the outdoor switchgear doubles. This advantage is often achieved by one-and-a-half schemes.

1.7. Scheme with two vimikachami on one connection

not at a voltage of 330 kV and higher in especially unusual surges. For example, at the AES and the great EU, which operate in isolated energy systems. The loss of such an EU could lead to a complete collapse of the energy system. In the winter, such an accident could cause not only a few businesses, but also the death of people.

The circuit (magnificent little 1.19) allows you to connect repairs without connecting

be it the impurities or the collected tires. Vaughn saves everything from the robot

connection to blame for such a dangerous problem as a short circuit on assembled tires.

Malyunok 1.19. Scheme with two vimikachami on one connection.

Schemes rich in cutaneous systems and schemes with the same type of attachments barely

So, due to the uninterrupted transfers, the equalized circuits and prefabricated tires have one hidden shortcoming. In the event of a short circuit on any attached relay,

This protection applies to the connection of two devices, so the number of operations involved in turning on and connecting the devices depends on the

operating costs and expenses grow responsibly.

In addition, ring circuits extract more folding protection from directional relays.