Control circuit of double static var generators of power supply system

Abstract

The utility model discloses a control circuit of a double static var generator of a power supply system, and relates to the technical field of power supply systems. According to the utility model, the first controller of the first static var generator can convert an electric signal into an optical signal through the first optical fiber transmitting module and transmit the optical signal to the second optical fiber receiving module of the second static var generator through the optical fiber; the second optical fiber receiving module converts the optical signal into an electric signal and transmits the electric signal to a second controller of a second static var generator; the second controller of the second static var generator can convert the electric signal into an optical signal through the second optical fiber transmitting module and transmit the optical signal to the first optical fiber receiving module of the first static var generator through the optical fiber; the first optical fiber receiving module converts the optical signal into an electric signal and transmits the electric signal to a first controller of the first static var generator; and bidirectional optical communication between the two static var generators is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply systems, in particular to a control circuit for a dual static var generator in a power supply system. Background Art

[0002] In the field of power supply, each of the two power supply buses (such as 110 kV) of the power supply system of some high-voltage electrical equipment (such as subways) is equipped with a static var generator (SVG). Under normal circumstances, the two SVG units independently perform reactive power compensation for their respective power supply buses. However, in some cases, it is necessary for the two SVG units to perform reactive power compensation for one of the power supply buses together, which requires two-way communication between the two SVG units. At present, however, two-way communication between the two SVG units in the power supply system cannot be achieved, affecting the dual-machine interconnection and collaborative compensation function of the two SVG units. Content of the Utility Model

[0003] The utility model solves the technical problem of how to achieve two-way communication between two SVG units in a power supply system by providing a control circuit for a dual static var generator in a power supply system.

[0004] The utility model provides the following technical solutions:

[0005] A control circuit for a dual static var generator in a power supply system includes a first controller, a first optical fiber transmitting module, and a first optical fiber receiving module deployed on a first static var generator, and a second controller, a second optical fiber transmitting module, and a second optical fiber receiving module deployed on a second static var generator;

[0006] The first controller is respectively communicatively connected to the first optical fiber transmitting module and the first optical fiber receiving module, the second controller is respectively communicatively connected to the second optical fiber transmitting module and the second optical fiber receiving module, the first optical fiber transmitting module is connected to the second optical fiber receiving module through an optical fiber, and the second optical fiber transmitting module is connected to the second optical fiber receiving module through an optical fiber.

[0007] Optionally, the first optical fiber transmitting module includes a gate driver and an optical fiber transmitter;

[0008] The first controller is connected to the input end of the gate driver, the output end of the gate driver is connected to the optical fiber transmitter, and the optical fiber transmitter is connected to the second optical fiber receiving module through an optical fiber.

[0009] Optionally, when a high level is input to the input end of the gate driver, its output end outputs a low level, and when a low level is input to the input end of the gate driver, its output end outputs a high level.

[0010] Optionally, the model of the optical fiber transmitter is T-1521.

[0011] Optionally, the circuit structure of the second optical fiber transmitting module is the same as that of the first optical fiber transmitting module.

[0012] Optionally, the second optical fiber receiving module includes an optical fiber receiver and an inverter;

[0013] The first optical fiber transmitting module is connected to the optical fiber receiver through an optical fiber. The output end of the optical fiber receiver is connected to the input end of the inverter, and the output end of the inverter is connected to the second controller.

[0014] Optionally, the optical fiber receiver outputs a high level when receiving an optical signal and outputs a low level when not receiving an optical signal.

[0015] Optionally, the model of the optical fiber receiver is R-2521.

[0016] Optionally, the circuit structure of the first optical fiber receiving module is the same as that of the second optical fiber receiving module.

[0017] Optionally, the control circuit further includes a DC power supply and an intermediate relay;

[0018] The coil of the intermediate relay is connected in series with the normally open auxiliary contact of the circuit breaker in the power supply system. The DC power supply is connected to the first controller and the second controller through the normally open contact of the intermediate relay.

[0019] The technical solution provided by the present utility model has at least the following technical effects or advantages:

[0020] The first controller of the first static var generator of the present utility model can convert an electrical signal into an optical signal through the first optical fiber transmitting module and transmit it to the second optical fiber receiving module of the second static var generator through an optical fiber. The second optical fiber receiving module then converts the optical signal into an electrical signal and transmits it to the second controller of the second static var generator; the second controller of the second static var generator can convert an electrical signal into an optical signal through the second optical fiber transmitting module and transmit it to the first optical fiber receiving module of the first static var generator through an optical fiber. The first optical fiber receiving module then converts the optical signal into an electrical signal and transmits it to the first controller of the first static var generator; realizing bidirectional optical communication between two static var generators. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a schematic diagram of the power supply system in the embodiment of the present utility model;

[0023] Figure 2 It is a schematic diagram of the control circuit of the dual static var generator of the power supply system in the embodiment of the present utility model;

[0024] Figure 3 It is another schematic diagram of the control circuit of the dual static var generator of the power supply system in the embodiment of the present utility model;

[0025] Figure 4 It is the circuit diagram of the first optical fiber transmitting module in the embodiment of the present utility model;

[0026] Figure 5 It is the circuit diagram of the second optical fiber receiving module in the embodiment of the present utility model;

[0027] Figure 6 It is another schematic diagram of the control circuit of the dual static var generator of the power supply system in the embodiment of the present utility model. Detailed implementation manners

[0028] The embodiment of the present utility model provides a control circuit for a dual static var generator of a power supply system, and solves the technical problem of how to achieve two-way communication between two SVG devices in the power supply system.

[0029] In order to better understand the technical solution of the present utility model, the technical solution of the present utility model will be described in detail below in conjunction with the specification drawings and specific implementation manners.

[0030] Such as Figure 1As shown in the figure, the power supply system of the embodiment of the present utility model includes two sections of first power supply buses, two sections of second power supply buses and two static var generators. The two sections of second power supply buses are connected by a first circuit breaker. The first section of the first power supply bus is connected to the first section of the second power supply bus through a series-connected second circuit breaker and a transformer. The first section of the second power supply bus is connected to the first static var generator through a series-connected fourth circuit breaker and a transformer. The second section of the first power supply bus is connected to the second section of the second power supply bus through a series-connected third circuit breaker and a transformer. The second section of the second power supply bus is connected to the second static var generator through a series-connected fifth circuit breaker and a transformer. Both ends of the two sections of second power supply buses are also respectively connected to a traction rectifier substation and a reactor, and the reactor is used to provide fixed reactive power. The voltage level of the first power supply bus can be 110 kV, the voltage level of the second power supply bus can be 35 kV, and the voltage level of the two static var generators can be 10 kV. Then, the transformers between the first section of the first power supply bus and the first section of the second power supply bus, and between the second section of the first power supply bus and the second section of the second power supply bus are all 110 / 35 kV transformers. The transformers between the first section of the second power supply bus and the first static var generator, and between the second section of the second power supply bus and the second static var generator are all 35 / 10 kV transformers.

[0031] Generally, when both sections of the first power supply buses are normal, the first circuit breaker will be in the open state, and the second, third, fourth, and fifth circuit breakers will all be in the closed state; when one of the first power supply buses is abnormal, for example, when the first section of the first power supply bus is abnormal, the first circuit breaker will become closed and the second circuit breaker will become open. When the second section of the first power supply bus is abnormal, the first circuit breaker will become closed and the third circuit breaker will become open. Generally, the switching states of the first, second, third, fourth, and fifth circuit breakers are judged manually. If it is judged manually that the first circuit breaker is in the open state and the second, third, fourth, and fifth circuit breakers are all in the closed state, then control both static var generators to work in the constant power factor mode; if it is judged manually that the first circuit breaker is in the closed state, one of the second and third circuit breakers is in the open state and the other is in the closed state, and the fourth and fifth circuit breakers are all in the closed state, then control one static var generator to work in the constant power factor mode and the other static var generator to work in the constant reactive power mode. The static var generator working in the constant power factor mode is the main machine, and the static var generator working in the constant reactive power mode is the slave machine. The main machine needs to allocate half of the required reactive power of the power supply system to the slave machine, which requires communication between the main and slave machines. And both static var generators will act as the main or slave machine, which requires two-way communication between the main and slave machines.

[0032] AsFigure 2 As shown in the figure, the control circuit of the dual static var generator of the power supply system according to the embodiment of the present utility model includes a first controller, a first optical fiber transmitting module, and a first optical fiber receiving module deployed on the first static var generator, and a second controller, a second optical fiber transmitting module, and a second optical fiber receiving module deployed on the second static var generator;

[0033] The first controller is respectively communicatively connected to the first optical fiber transmitting module and the first optical fiber receiving module, the second controller is respectively communicatively connected to the second optical fiber transmitting module and the second optical fiber receiving module, the first optical fiber transmitting module is connected to the second optical fiber receiving module through an optical fiber, and the second optical fiber transmitting module is connected to the second optical fiber receiving module through an optical fiber.

[0034] Among them, the first controller and the second controller are used to output electrical signals, the first optical fiber transmitting module and the second optical fiber transmitting module are used to convert the electrical signals into optical signals, the optical signals are transmitted in the optical fiber, and the first optical fiber receiving module and the second optical fiber receiving module are used to convert the optical signals into electrical signals. In this way, the first controller of the first static var generator can convert the electrical signal into an optical signal through the first optical fiber transmitting module and transmit it to the second optical fiber receiving module of the second static var generator through the optical fiber, and the second optical fiber receiving module then converts the optical signal into an electrical signal and transmits it to the second controller of the second static var generator; the second controller of the second static var generator can convert the electrical signal into an optical signal through the second optical fiber transmitting module and transmit it to the first optical fiber receiving module of the first static var generator through the optical fiber, and the first optical fiber receiving module then converts the optical signal into an electrical signal and transmits it to the first controller of the first static var generator; realizing bidirectional optical communication between the two static var generators.

[0035] Specifically, as Figure 3 shown, the first optical fiber transmitting module may include a gate driver and an optical fiber transmitter; the first controller is connected to the input end of the gate driver, the output end of the gate driver is connected to the optical fiber transmitter, and the optical fiber transmitter is connected to the second optical fiber receiving module through an optical fiber. Among them, the gate driver is used to drive the optical fiber transmitter to emit an optical signal. When a high level is input to the input end of the gate driver, its output end outputs a low level, and when a low level is input to the input end of the gate driver, its output end outputs a high level.

[0036] Specifically, as Figure 3 shown, the second optical fiber receiving module may include an optical fiber receiver and an inverter; the first optical fiber transmitting module is connected to the optical fiber receiver through an optical fiber, the output end of the optical fiber receiver is connected to the input end of the inverter, and the output end of the inverter is connected to the second controller. Among them, the optical fiber receiver outputs a high level when receiving an optical signal and outputs a low level when not receiving an optical signal.

[0037] Taking the model number of the gate driver as SN75451BD, the model number of the fiber optic transmitter as T-1521, the model number of the fiber optic receiver as R-2521, and the model number of the inverter as 74LS14 as an example, the fiber optic transmitter is connected to the fiber optic receiver through a fiber optic cable, as Figure 4 and Figure 5 shown. The electrical signal output by the first controller is GX_OTS2, and GX_OTS2 can be a square wave with a frequency of 5M and an amplitude of 5V.

[0038] When the electrical signal output by the first controller is at a high level, the 1A pin of the gate driver U5 of the first fiber optic transmission module inputs a high level, the 1Y pin of the gate driver U5 outputs a low level, the 1 and 2 pins of the fiber optic transmitter U7 are connected, the fiber optic transmitter U7 emits an optical signal, the optical signal is transmitted through the fiber optic cable to the fiber optic receiver U9 of the second fiber optic reception module, the 1 and 3 pins of the fiber optic receiver U9 are conducted, and the electrical signal GX_IRS0_A0 output by the fiber optic receiver U9 is at a high level and given to the 4A pin of the inverter U31. The electrical signal GX_IRS0 output by the 4Y pin of the inverter U31 is at a low level and given to the second controller, completing the transmission of the high-level signal from the first controller to the second controller.

[0039] When the electrical signal output by the first controller is at a low level, the 1A pin of the gate driver U5 of the first fiber optic transmission module inputs a low level, the 1Y pin of the gate driver U5 outputs a high level, the 1 and 2 pins of the fiber optic transmitter U7 are disconnected, the fiber optic transmitter U7 does not emit an optical signal, the 1 and 3 pins of the fiber optic receiver U9 are disconnected when the fiber optic receiver U9 does not receive an optical signal, the electrical signal GX_IRS0_A0 output by the fiber optic receiver U9 is at a low level and given to the 4A pin of the inverter U31. The electrical signal GX_IRS0 output by the 4Y pin of the inverter U31 is at a high level and given to the second controller, completing the transmission of the low-level signal from the first controller to the second controller.

[0040] Furthermore, the circuit structure of the second fiber optic transmission module can be the same as that of the first fiber optic transmission module, and the circuit structure of the first fiber optic reception module can be the same as that of the second fiber optic reception module, which will not be repeated here.

[0041] As mentioned above, it is generally necessary for manual judgment of the switch states of the first circuit breaker, the second circuit breaker, the third circuit breaker, the fourth circuit breaker, and the fifth circuit breaker, and the efficiency of detecting the switch states of the circuit breakers is low. To improve the detection efficiency of the switch states of the circuit breakers, as Figure 6As shown, the control circuit of the embodiment of the present invention may further include a DC power supply and an intermediate relay; the coil of the intermediate relay is connected in series with the normally open auxiliary contact of the circuit breaker in the power supply system, and the DC power supply is connected to the first controller and the second controller through the normally open contact of the intermediate relay. Among them, the circuit breaker can be any one of the first circuit breaker, the second circuit breaker, the third circuit breaker, the fourth circuit breaker and the fifth circuit breaker; the normally open auxiliary contact of the circuit breaker is consistent with the switch state of the circuit breaker; the coil of the intermediate relay is connected in series with the normally open auxiliary contact of the circuit breaker in the power supply system, which means that the coil of the intermediate relay is energized when the normally open auxiliary contact of the circuit breaker is closed and the coil of the intermediate relay is de-energized when the normally open auxiliary contact of the circuit breaker is opened; the voltage output by the DC power supply can be 24V.

[0042] When the circuit breaker is open, the normally open auxiliary contact of the circuit breaker is open, the coil of the intermediate relay is de-energized, the normally open contact of the intermediate relay is open, and the DC power supply does not supply power to the first controller and the second controller. The first controller and the second controller can thus determine that the circuit breaker is in the open state. When the circuit breaker is closed, the normally open auxiliary contact of the circuit breaker is closed, the coil of the intermediate relay is energized, the normally open contact of the intermediate relay is closed, and the DC power supply supplies power to the first controller and the second controller through the normally open contact of the intermediate relay. The first controller and the second controller can thus determine that the circuit breaker is in the closed state. Thus, the switch state of the circuit breaker in the power supply system can be automatically detected, improving the detection efficiency.

[0043] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0044] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A control circuit for a dual static var generator of a power supply system, characterized in that, It includes a first controller, a first optical fiber transmitting module, and a first optical fiber receiving module deployed on the first static var generator, as well as a second controller, a second optical fiber transmitting module, and a second optical fiber receiving module deployed on the second static var generator; The first controller is respectively communicatively connected to the first optical fiber transmitting module and the first optical fiber receiving module. The second controller is respectively communicatively connected to the second optical fiber transmitting module and the second optical fiber receiving module. The first optical fiber transmitting module is connected to the second optical fiber receiving module through an optical fiber, and the second optical fiber transmitting module is connected to the second optical fiber receiving module through an optical fiber.

2. The control circuit of the dual static var generator of the power supply system according to claim 1, characterized in that, The first optical fiber transmitting module includes a gate driver and an optical fiber transmitter; The first controller is connected to the input end of the gate driver. The output end of the gate driver is connected to the optical fiber transmitter, and the optical fiber transmitter is connected to the second optical fiber receiving module through an optical fiber.

3. The control circuit of the dual static var generator of the power supply system according to claim 2, wherein When a high level is input to the input end of the gate driver, its output end outputs a low level. When a low level is input to the input end of the gate driver, its output end outputs a high level.

4. The control circuit of the dual static var generator of the power supply system according to claim 3, characterized in that The model of the optical fiber transmitter is T-1521.

5. The control circuit of the dual static var generator of the power supply system according to any one of claims 1-4, characterized in that, The circuit structure of the second optical fiber transmitting module is the same as that of the first optical fiber transmitting module.

6. The control circuit of the dual static var generator of the power supply system according to claim 1, characterized in that, The second optical fiber receiving module includes an optical fiber receiver and an inverter; The first optical fiber transmitting module is connected to the optical fiber receiver through an optical fiber. The output end of the optical fiber receiver is connected to the input end of the inverter, and the output end of the inverter is connected to the second controller.

7. The control circuit of the dual static var generator of the power supply system according to claim 6, characterized in that, The optical fiber receiver outputs a high level when it receives an optical signal and outputs a low level when it does not receive an optical signal.

8. The control circuit of the dual static var generator of the power supply system according to claim 7, characterized in that, The model of the optical fiber receiver is R-2521.

9. The control circuit of the dual static var generator of the power supply system according to any one of claims 6-8, characterized in that, The circuit structure of the first optical fiber receiving module is the same as that of the second optical fiber receiving module.

10. The control circuit of the dual static var generator of the power supply system according to claim 1, characterized in that, The control circuit further includes a DC power supply and an intermediate relay; The coil of the intermediate relay is connected in series with the normally open auxiliary contact of the circuit breaker in the power supply system. The DC power supply is connected to the first controller and the second controller through the normally open contact of the intermediate relay.

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