CN115693765A - Active power reverse transmission control system and control method for urban rail transit - Google Patents

Abstract

The invention discloses an active power reverse transmission control system for urban rail transit, which comprises a control center, a subway energy feedback device, a main transformer station and N traction transformer stations, wherein N is more than or equal to 2; the control center is located in the main transformer substation, and the subway energy feedback device is located in the traction transformer substation. The active power reverse transmission control method comprises the following steps: the control center respectively monitors the active power of the I section bus and the II section bus of the main transformer station; if active power reverse transmission occurs in a certain section of bus, the subway energy feedback device is controlled to feed back the starting threshold, the feedback power is transferred to another section of bus, and the active power reverse transmission phenomenon of the section of bus is inhibited. The invention balances the loads of the I section bus and the II section bus of the main transformer station by adopting a feedback power transfer mode, can still effectively inhibit the main and all power transmission phenomena under the condition that the on-board resistance of the whole subway train is cancelled, and improves the energy-saving effect of the urban rail power supply system.

Description

A kind of control system and control method for active power reversing of urban rail transit

technical field

The invention relates to an active power reversing control system, in particular to an active power reversing control system and a control method for urban rail transit.

Background technique

At present, the on-board resistance of subway trains brings problems such as loss, heat generation, noise, and elevated tunnel ambient temperature. It has become a major trend to cancel the on-board resistance of all trains. After canceling the on-board resistance of all trains, the braking energy generated when the subway train brakes cannot be consumed, and the power fed back to the power grid through the subway energy device continues to increase. In the early stage of subway operation and for suburban lines, due to the low load of the main substation and the large feedback power of the subway energy feedback device, active power reversion of the main substation frequently occurs, and the active power reversion accounts for a large proportion of the total energy feedback of the entire subway line. Since the power transferred by the active power of the main substation cannot be measured, it will greatly reduce the energy-saving benefits of the subway company and reduce the energy-saving indicators of the urban rail power supply system.

In the prior art, in order to solve the problem of active power transfer in the main substation of the urban rail power supply system, there are mainly two solutions: limiting the power of the subway energy feedback device and setting up an energy storage device. For example, in the method proposed by the patent CN111490535A, when the active power transfer occurs in the main substation, the power of the subway energy feedback device is limited, the excess feedback power is consumed through the on-board resistance, and the main power transfer power is reduced, but on the one hand, this method causes energy The loss is not energy-saving and uneconomical, and on the other hand, it is not suitable for lines that cancel the on-board resistance of the entire line of trains. The scheme of installing energy storage devices in the main substation or the traction substation increases the equipment investment on the one hand, and on the other hand, it is difficult to implement the transformation for the lines that have been put into operation.

Contents of the invention

Object of the invention: The object of the present invention is to provide an urban rail transit active power transfer control system and control method that can effectively suppress the active power transfer phenomenon of the main substation without causing energy loss.

Technical solution: The urban rail transit active power transfer control system of the present invention includes a control center, N subway energy feedback devices, a main substation, N traction substations and a DC power supply network, N≥2;

The main substation adopts a single-female segmented wiring mode to connect the grid incoming line and the medium-voltage power supply network; the N traction substations adopt a single-female segmented wiring mode to connect the medium-voltage power supply network and the DC power supply network;

The control center is located in the main substation, and monitors the active power of the I-section busbar and the II-section busbar of the main substation in real time; each traction substation is equipped with a set of traction rectifier units and a subway energy feedback device, and the subway energy of the adjacent traction substation The feedback device is connected to the bus bars of different sections of the traction substation; the DC power supply network is mainly composed of catenary and rails, and the positive and negative poles of each traction substation are respectively connected to the catenary and the rails.

Further, the control center communicates with each subway energy feedback device through a real-time communication network.

Further, the control center adjusts the activation threshold of each subway energy feedback device in real time through the communication network.

The control method of the above-mentioned urban rail transit active power reversing control system comprises the following steps:

S1, the control center monitors the active power of the first-section busbar and the second-section busbar of the main substation in real time, and obtains the feedback power and start-up threshold of each subway energy feedback device in real time;

S2, when the control center monitors that active power reversing occurs in a certain section of the bus, according to the feedback power of the subway energy feedback device, determine the subway energy feedback device that needs to participate in active power reversing;

S3, the control center increases the starting threshold of the subway energy feedback device participating in the active power reverse transmission, and lowers the starting threshold of the subway energy feedback device of its adjacent traction substation, so that the feedback power is transferred to the subway energy feedback device of its adjacent traction substation, It is sent to the corresponding load of the other section of the bus in the main substation;

S4, when the control center detects that the phenomenon of active power reversing disappears, gradually restore the activation threshold of the subway energy feedback device participating in active power reversing to the initial value.

Further, in step S2, when the control center detects active power reversing in a certain section of the busbar, the subway energy feedback device whose feedback power is greater than K times the rated power is determined as participating in active power reversing, and the value of K ranges from 0.2 to 1.

Further, in step S3, the control center gradually increases the starting threshold of the subway energy feedback device participating in the active power transfer, and the upper limit does not exceed the set voltage for safe operation of the train; at the same time, gradually reduces the starting threshold of the subway energy feedback device at its adjacent station , the lower limit is not lower than the set no-load grid voltage of the traction rectifier unit.

The present invention compares with prior art, and its remarkable effect is as follows:

By adopting the method of feedback power transfer, the loads of the I-section busbar and II-section busbar of the main substation are balanced, and the problem of active power reversing in the main substation is effectively solved in the case of canceling the on-board resistance of the train on the whole line, and the energy-saving benefits of the urban rail power supply system are improved. Adding additional energy storage equipment, the implementation of the overall scheme has little change, and it is easy to apply and promote.

Description of drawings

Fig. 1 is the topological schematic diagram of the urban rail transit active power reversing control system of the present invention;

Fig. 2 is the schematic diagram of the control method of the urban rail transit active power reversing control system of the present invention;

Explanation of symbols in the figure: 1. Transformer of the first main substation; 2. Transformer of the second main substation; 3. Control center; 4. First traction rectifier unit; 5. First subway energy feedback device; 6. Second subway energy feedback 7. The second traction rectifier unit; 8. The Nth traction rectifier unit; 9. The Nth subway energy feedback device; 10. The 110kV incoming line of section I of the first main substation; 11. The 110kV bus tie switch of the first main substation; 12. The 110kV incoming line of the second main substation II section; 13. The main substation; 14. The 35kV I section bus of the first traction substation; 15. The 35kV bus tie switch of the first traction substation; 16. The 35kV II section bus of the first traction substation; 17. The 35kV section I busbar of the second traction substation; 18. The 35kV bus tie switch of the second traction substation; 19. The 35kV section II busbar of the second traction substation; 20. The 35kV section I busbar of the Nth traction substation; 21. The Nth traction substation 35kV bus tie switch; 22. 35kV II section bus of the Nth traction substation; 23. The first traction substation; 24. The second traction substation; 25. The Nth traction substation; 26. DC catenary; 27. Rails.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

The active power transfer control system of the present invention includes a control center 3, N subway energy feedback devices, a main substation 13 and N traction substations, where N≥2. The control center 3 and each subway energy feedback device communicate with each other through the real-time communication network. At the same time, the control center 3 adjusts the activation threshold of each subway energy feedback device in real time through the communication network. The main substation adopts a single-female segmented wiring mode to connect the grid incoming line and the medium-voltage power supply network; the N traction substations adopt a single-female segmented wiring mode to connect the medium-voltage power supply network and the DC power supply network. The control center is located in the main substation, and monitors the active power of the first-section busbar and the second-section busbar of the main substation in real time; each traction substation is equipped with a set of traction rectifier units and a subway energy feedback device, and the subway energy feedback device of the adjacent traction substation Connected to different sections of busbars in the traction substation; the DC power supply network is mainly composed of catenary and rails, and the positive and negative poles of each traction substation are connected to the catenary and rails respectively.

As shown in Figure 1, the active power reverse transmission control system of the present invention includes a control center 3, a first subway energy feedback device 5, a second subway energy feedback device 6, an Nth subway energy feedback device 9, a main substation 13, a first traction A substation 23 , a second traction substation 24 and an Nth traction substation 25 . The first traction substation 23 is provided with the first traction rectifier unit 4 and the first subway energy feedback device 5, the second traction substation 24 is provided with the second subway energy feedback device 6 and the second traction rectifier unit 7, and the Nth traction substation The Nth traction rectifier unit 8 and the Nth subway energy feedback device 9 are arranged in the 25 . The 110kV incoming line 10 of section I of the first main substation is connected with the 110kV incoming line 12 of section II of the second main substation through the 110kV bus tie switch 11 of the first main substation, and the 35kV section I busbar 14 of the first traction substation is connected with the 35kV section II of the first traction substation The busbar 16 is connected through the 35kV bus tie switch 15 of the first traction substation; The first traction rectifier unit 4 is connected to the 35kV section bus 14 of the first traction substation, the first subway energy feedback device 5 is connected to the 35kV II section bus 16 of the first traction substation; the second subway energy feedback device 6 is connected to the second traction substation 35kV I Section bus 17 is connected, the second traction rectifier unit 7 is connected with the second traction substation 35kV II section bus 19; the Nth traction rectifier unit 8 is connected with the Nth traction substation 35kV I section bus 20, the Nth subway energy feedback device 9 is connected with the No. N traction substation 35kV II section bus 22 connection.

The incoming line side of the main substation 13 is connected to the 110kV incoming line 10 of the main substation I section and the 110kV incoming line 12 of the main substation II section, and the outgoing line side is connected to the 35kV I section bus bar 14 of the first traction substation and the 35kV II section bus bar 16 of the first traction substation. The single-female segmented wiring method is adopted to connect the grid incoming line and the medium-voltage power supply network. Taking the first traction substation 23 as an example, the incoming line side is connected to the first traction substation 35kV Section I busbar 14 and the first traction substation 35kV Section II busbar 16. The side bus adopts the single bus segment connection mode.

The transformer 1 of the first main substation, the transformer 2 of the second main substation and the control center 3 are located in the main substation 13. The control center 3 simultaneously monitors the 110kV incoming line 10 of the main substation I section and the 110kV incoming line 12 of the main substation II section corresponding to the high voltage side of the main transformer Active power; the first subway energy feedback device 5 is located in the first traction substation 23, and the adjacent second subway energy feedback device 6 is located in the second traction substation 24, and is alternately connected to the first traction substation 35kV I section 14 and the first traction substation. 35kV Section II busbar 16 in the traction substation;

The control center 3 communicates with the first subway energy feedback device 5, the second subway energy feedback device 6, ..., the Nth subway energy feedback device 9, and obtains the feedback power value and the start threshold parameter of each station subway energy feedback device in real time. The initial value of the starting threshold of each subway energy feedback device is 1750V.

As shown in Figure 2, the control center 3 of the present invention performs the active power reverse transmission suppression of the main substation according to the following steps:

Step 1, when the control center 3 monitors that the active power corresponding to the 110kV incoming line 10 of section I of the first main substation is less than 0, immediately check the feedback work of the subway energy feedback device corresponding to the 110kV incoming line 10 of section I of the first main substation; determine the feedback power A subway energy feedback device with a power greater than 0.5 times the rated power is a subway energy feedback device that participates in active power reversing;

Step 2. Gradually increase the start-up threshold of the subway energy feedback device participating in active power reverse transmission. The upper limit should not exceed the train’s safe operating voltage of 1800V; at the same time, gradually reduce the start-up threshold of the subway energy feedback device in its adjacent stations. The lower limit should not be lower than the traction rectifier unit The no-load network voltage is 1680V.

Step 3: When the control center monitors that the active power of the 110kV incoming line 10 of section I of the first main substation is greater than 0, gradually restore the activation threshold of the subway energy feedback devices participating in active power transfer and adjacent stations to the initial value of 1750V.

The above embodiments are only used to illustrate the technical solution of the present invention rather than limit it, and various modifications or changes made with reference to the above embodiments are within the protection scope of the present invention.

Claims (6)

1. An urban rail transit active power transfer control system, characterized in that it comprises a control center, N subway energy feedback devices, a main substation, N traction substations and a DC power supply network, N≥2; The main substation adopts a single-female segmented wiring mode to connect the grid incoming line and the medium-voltage power supply network; the N traction substations adopt a single-female segmented wiring mode to connect the medium-voltage power supply network and the DC power supply network; The control center is located in the main substation, and monitors the active power of the I-section busbar and the II-section busbar of the main substation in real time; each traction substation is equipped with a set of traction rectifier units and a subway energy feedback device, and the subway energy of the adjacent traction substation The feedback device is connected to the bus bars of different sections of the traction substation; the DC power supply network is mainly composed of catenary and rails, and the positive and negative poles of each traction substation are respectively connected to the catenary and the rails. 2. The urban rail transit active power transfer system according to claim 1, wherein the control center communicates with each subway energy feedback device through a real-time communication network. 3. The urban rail transit active power reversing system according to claim 1, wherein the control center adjusts the activation threshold of each subway energy feedback device in real time through the communication network. 4. the control method of the urban rail transit active power reversing control system as described in any one of claim 1-3, is characterized in that, comprises the steps: S1, the control center monitors the active power of the first-section busbar and the second-section busbar of the main substation in real time, and obtains the feedback power and start-up threshold of each subway energy feedback device in real time; S2, when the control center monitors that active power reversing occurs in a certain section of the bus, according to the feedback power of the subway energy feedback device, determine the subway energy feedback device that needs to participate in active power reversing; S3, the control center increases the starting threshold of the subway energy feedback device participating in the active power reverse transmission, and lowers the starting threshold of the subway energy feedback device of its adjacent traction substation, so that the feedback power is transferred to the subway energy feedback device of its adjacent traction substation, It is sent to the corresponding load of the other section of the bus in the main substation; S4, when the control center detects that the phenomenon of active power reversing disappears, gradually restore the activation threshold of the subway energy feedback device participating in active power reversing to the initial value. 5. The control method of the urban rail transit active power reversing control system according to claim 4, characterized in that, in step S2, when the control center detects that a certain section of the busbar has active power reversing, the feedback power is greater than K times the rated power The subway energy feedback device with high power is determined to participate in the active power transfer, and the value of K ranges from 0.2 to 1. 6. The control method of the urban rail transit active power reversing control system according to claim 4, characterized in that, in step S3, the control center gradually increases the starting threshold of the subway energy feedback device participating in active reversing, and the upper limit is not Exceed the set voltage for safe operation of the train; at the same time, gradually lower the start-up threshold of the subway energy feedback device at its adjacent station, and the lower limit shall not be lower than the set no-load network voltage of the traction rectifier unit.

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