A protection test device and control method for a large-area power supply system of a subway

Abstract

The present invention discloses a protection test device for a large-area power supply system of a subway and a control method thereof, comprising: a relay protection tester, a voltage shunt module, a current shunt module, a protection device to be tested, and a monitoring module. The voltage shunt module comprises: a plurality of contactors, the input ends of which are connected in parallel to the three-phase voltage of the output end of the relay protection tester, and the output ends thereof are respectively connected to the protection devices to be tested at each interval on the same bus; the current shunt module comprises: a plurality of single-pole double-throw switches connected in series to the current loop of the protection device to be tested, the fault ends of which are short-circuited and connected to the current common end of the relay protection tester; the monitoring module determines whether the subway protection has determined and isolated the fault section according to the protection device action time recorded by the relay protection tester and the protection device action message received.

Description

Technical Field

[0001] The present invention relates to the technical field of power system testing, and in particular to a protection testing device for a large-area power supply system of a subway and a control method thereof. Background Art

[0002] With the prosperity of cities and economic development, urban traffic congestion is accompanied. The main way to improve urban public transportation conditions is to adopt a rail transit system with a large passenger volume. The power source of the rail transit system is the urban rail transit power supply system. In recent years, in order to reduce the investment in ring network cables and the comprehensive cost, large-district rail transit power supply systems have gradually become a trend. The rail transit power supply system is different from the conventional distribution network power supply system, and its safe and stable operation is crucial. Various types of short-circuit faults are one of the biggest hidden dangers for the safe operation of the rail transit power supply system, especially fires caused by short-circuit faults often cause serious casualties. In order to ensure the safe and reliable operation of the large-district power supply system of the subway, the optimization of the urban rail transit protection scheme and the corresponding protection technology have been the focus of research in the domestic and foreign industries in recent years. Foreign manufacturers rely on their strong technical strength to almost occupy the entire domestic urban rail transit protection equipment market. In order to break the monopoly of foreign manufacturers on the market, promote the localization of equipment, and ensure the feasibility, reliability and accuracy of the protection scheme of the large-district power supply system of the subway, system-level testing and verification must be carried out.

[0003] When testing the protection system level of the large-area power supply system of the subway, it is necessary to build a typical power supply area. According to the operation mode and the location of the fault point, the fault voltage and fault current are applied to the protection devices of multiple substations in the power supply area. In order to truly simulate the actual working conditions, many sets of independent voltages and currents need to be applied. At present, a relay protection tester cannot provide so many voltage and current channels. Multiple relay protection tests face problems such as data synchronization between testers and high equipment investment costs. When testing the subway power supply system, it is mainly achieved by constantly replacing the test line. On the one hand, it cannot truly simulate the distribution and changes of the fault voltage and current. On the other hand, different fault points need to constantly replace the wiring, and the test efficiency is low.

[0004] There are two existing technical solutions: one is to use the RTDS simulator to build a simulation model of the large-area power supply system of the subway, form a closed-loop test environment with the help of the interface board and the equipment under test, and simulate various faults in the system to achieve the purpose of evaluating the equipment under test. The RTDS simulator is expensive and cannot be equipped in general laboratories. The test environment is relatively complicated to set up and cannot meet the requirements of test convenience and test efficiency during the research and development test process. The second is to use multiple relay protection testers to provide more voltage sources and current sources. Different testers are connected to different intervals, and the faults are simulated through the coordination between the state sequences of the testers to evaluate the equipment under test. On the one hand, multiple relay protection testers cannot achieve unified and precise control of multiple clients, and it is difficult to ensure the timing of simulated faults. On the other hand, it is difficult to synchronize data between different testers. Summary of the invention

[0005] The purpose of the embodiment of the present invention is to provide a protection test device for a large-area power supply system of a subway and a control method thereof. The voltage source and current source of a relay protection tester are expanded through a voltage shunt circuit and a current shunt circuit, thereby solving the problem of insufficient number of voltage and current sources of the relay protection tester during the protection test of the large-area power supply system of the subway. The device can truly simulate the changes in the bus voltage and current of each substation after faults occur in different operating modes and locations of the power supply system and the protection action trips the circuit breaker. The device has the characteristics of not requiring wiring to be replaced during the test, being economical and reliable, and being applicable to various protection tests of the large-area power supply system of the subway.

[0006] In order to solve the above technical problems, a first aspect of an embodiment of the present invention provides a protection test device for a large-area power supply system of a subway, comprising: a relay protection tester, a voltage shunt module, a current shunt module, a protection device to be tested, and a monitoring module;

[0007] The voltage shunt module comprises: a plurality of contactor groups, the input ends of the plurality of contactor groups are connected in parallel to the three-phase voltage of the output end of the relay protection tester, and the output ends thereof are respectively connected to the protection devices to be tested at each interval on the same bus;

[0008] The current shunt module comprises: a plurality of groups of single-pole double-throw switches connected in series to the current loop of the protection device under test, the fault ends of which are short-circuited and connected to the current common end of the relay protection tester;

[0009] The monitoring module determines whether the subway protection has identified and isolated the fault section based on the protection device action time recorded by the relay protection tester and the protection device action message received.

[0010] Further, the protection interval is provided with a simulated circuit breaker;

[0011] The tripping / closing output of the protection device is connected to the tripping / closing coil of the simulated circuit breaker of the corresponding interval, and the tripping / closing input of the protection device is connected to the tripping / closing contacts of the simulated circuit breaker of the corresponding interval.

[0012] Furthermore, the three-phase main contact input end of the contactor is connected in parallel to the three-phase voltage of the relay protection tester, and its main contact output end is respectively connected to each interval protection device under test connected on the same bus, one end of the coil of the contactor is short-circuited and connected to the positive power supply, and the other end of the coil is connected in series with an output of the tester and then connected to the negative power supply.

[0013] Furthermore, the current output by the relay protection tester is connected in series with the current loop of the protection device under test in each of the intervals in sequence according to the power supply direction, and then connected in series with a single-pole double-throw switch. When the current is connected in series with the single-pole double-throw switch, it is connected from its input end and output from its normal operating end. The fault end of the single-pole double-throw switch is short-circuited and then connected to the current common end of the relay protection tester.

[0014] Furthermore, the subway large-area power supply system protection test device also includes: a clock source, which is respectively connected to all the protection devices and sends clock signals to all the protection devices.

[0015] Accordingly, a first aspect of an embodiment of the present invention provides a method for controlling a large-area power supply system protection test device for a subway, which is used to control any of the above-mentioned large-area power supply system protection test devices for a subway, and comprises the following steps:

[0016] When simulating a fault, the operating states of several groups of single-pole double-throw switches are set in the current shunt device according to the location of the fault point and the type of fault;

[0017] Predict the bus voltage of each section and the fault current of each interval according to the test items, and set the voltage and current values ​​in the relay protection tester according to the prediction results;

[0018] In each state sequence, a plurality of groups of contactor coils connected in series are arranged to form the output state of the relay protection tester;

[0019] The action time of the protection device recorded by the relay protection tester and the action message of the protection device sent to the monitoring module are used to determine whether the subway protection has identified and isolated the fault section.

[0020] The above technical solution of the embodiment of the present invention has the following beneficial technical effects:

[0021] The voltage source and current source of the relay protection tester are expanded through voltage shunt circuit and current shunt circuit, which solves the problem of insufficient voltage and current sources of the relay protection tester during protection testing of large-area power supply systems in subways. It can truly simulate the changes in bus voltage and current of each substation and each interval after faults occur in different operating modes and locations of the power supply system and the protection action trips the circuit breaker. It has the characteristics of not requiring wiring replacement during the test, being economical and reliable, and being applicable to various protection tests of large-area power supply systems in subways. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a protection test device for a large-area power supply system of a subway provided by an embodiment of the present invention;

[0023] Figure 2 It is a large-area power supply system and protection configuration diagram provided by an embodiment of the present invention;

[0024] Figure 3 It is the principle and wiring diagram of the voltage splitting device provided by the embodiment of the present invention;

[0025] Figure 4 It is the principle and wiring diagram of the current shunt device provided by the embodiment of the present invention;

[0026] Figure 5 It is a flow chart of a control method of a protection test device for a large-area power supply system of a subway provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0028] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4The first aspect of the embodiment of the present invention provides a protection test device for a large-area power supply system of a subway, including: a relay protection tester, a voltage shunt module, a current shunt module, a protection device under test, and a monitoring module. The voltage shunt module includes: a plurality of contactors, the input ends of which are connected in parallel to the three-phase voltage of the output end of the relay protection tester, and the output ends thereof are respectively connected to the protection devices under test at each interval on the same bus; the current shunt module includes: a plurality of single-pole double-throw switches connected in series to the current loop of the protection device under test, the fault ends of which are short-circuited and connected to the current common end In of the relay protection tester; the monitoring module determines whether the subway protection has determined and isolated the fault section according to the protection device action time recorded by the relay protection tester and the protection device action message received.

[0029] According to the operation mode and direction of the power supply system, the currents of the protection devices at each interval from the same power source during normal operation are connected in series in sequence through the current shunt device, and the voltages of the protection devices at each interval connected on the same bus are connected in parallel after passing through the voltage shunt device.

[0030] Among them, the current shunt module is composed of several groups of single-pole double-throw switches. The current output by the tester is connected in series to the current loop of the protection device of each interval in the power supply direction, and then connected in series to the single-pole double-throw switch (Single Pole Double Throw, hereinafter referred to as SPDT). When the current is connected in series to the SPDT, it is connected through the SPDT input terminal and output through the first output terminal of the SPDT (i.e., the normal operation terminal). The second output terminal (i.e., the fault terminal) of each group of SPDT is short-circuited and connected to the tester In.

[0031] The voltage shunt device is composed of multiple groups of contactors. The three-phase main contact input end of each group of contactors is connected in parallel to the three-phase voltage of the tester, and the main contact output end is connected to each interval protection device connected on the same bus. One end of each group of contactor coils is short-circuited and connected to the positive power supply, and the other end is connected in series with the output of a tester and then connected to the negative power supply, so as to control the opening and closing of the contactor main contacts and simulate whether each bus has voltage.

[0032] In a specific implementation of an embodiment of the present invention, in order to avoid the test system being too large, the protection device is configured at the minimum scale that can comprehensively evaluate the protection plan of the large-area power supply system of the subway: the protection device is configured according to the three substations in the power supply area, of which the second substation is configured with all the protection devices, and the other substations are only configured with incoming and outgoing line protection devices and only configured on the I mother. Interlocking signals and fiber optic channels are connected between protection devices. All protection devices are connected to the monitoring background and receive synchronization signals from the same GPS clock. The simulated large-area power supply system and protection configuration are as follows: Figure 2As shown, protection is configured for incoming and outgoing line bays 1 to 8, busbar bay 9, and feeder bay 10. All interlocking signals between devices (including start interlocking, failure start, inter-tripping, device abnormality, etc.) are connected according to the requirements of the protection scheme.

[0033] The voltage shunt module consists of multiple groups of contactors, such as Figure 3 As shown, the three-phase main contact input terminals of each group of contactors are connected in parallel to the three-phase voltage of the tester, and the main contact output terminals are respectively connected to the interval protection devices connected on the same bus. One end of each group of contactor coils is short-circuited and connected to the positive power supply, and the other end is connected in series with a tester output and then connected to the negative power supply. When the incoming circuit breakers of each bus are in the closed position, the voltage of each bus is the output voltage of the tester, and the output state of the tester connected in series with each contactor coil is set to the closed state; when the incoming circuit breaker on a certain section of the bus is tripped, the voltage of the bus and all subsequent buses in the power supply direction is 0, and the output state of the tester connected in series with the contactor coils corresponding to the bus and subsequent sections of the bus is set to the disconnected state. Through the setting of the tester output state, the main contacts of the contactor can be independently controlled to open and close, simulating the effect of whether each bus has pressure.

[0034] According to the operation mode and direction of the power supply system, the currents of the various interval protection devices that come from the same power supply during normal operation are connected in series in sequence through the current shunt device. Figure 4 As shown, the current shunt device is composed of multiple groups of SPDs. The current output by the tester is connected in series to the current loop of the protection device of each interval in the power supply direction, and then connected in series to the SPDT. When the current is connected in series to the SPDT, it is connected through the SPDT input terminal and output through the first output terminal of the SPDT (i.e. normal operation). The second output terminal (i.e. fault) of each group of SPDT is short-circuited and connected to the tester In. In normal operation, the SPDT is set to the normal operating position, and the same current flows through all the incoming and outgoing line intervals; in the event of a fault, the SPDT of the corresponding interval is set to the fault position, and the current flows directly back to the tester, and the fault phase of each protection device after the SPDT has no current. This can achieve the effect of truly simulating the fault phase current of the interval after the fault point in the power supply direction to be 0.

[0035] When simulating a fault, set the position of each group of SPDT in the current shunt device according to the location of the fault point and the type of fault (normal operation / fault); predict the voltage of each section of the busbar and the fault current of each interval according to the test items, set the corresponding voltage and current values ​​in the tester state sequence according to the prediction results, and set the tester output state of each group of contactor coils in series in each state sequence. For example, if you simulate the AN fault at K5 point, press Figure 2The operation mode and power supply direction shown in the figure, first put the A phase of the SPDT corresponding to the bay 2 in the current shunt device in the fault position; set the voltage and current values ​​under different test states in the tester state sequence, and before the bay 2 circuit breaker is tripped, the tester output state of each group of contactor coils in series is closed. When the bay 2 and bay 3 protections operate correctly and trip the corresponding circuit breakers, the tester output state of the series of the Ⅰ bus contactor coils of the substation 2 is disconnected, and the Ⅰ bus of the substation 2 is without pressure. At this time, the Ⅱ bus voltage of the substation 2 is normal, and the bus coupling bay 9 is automatically closed to realize the power supply from the power supply 2 to the Ⅰ bus and Ⅱ bus loads of the substation 2 and the subsequent substations.

[0036] After the settings are completed, the test begins. By recording the action time of each protection device through the relay protection tester and the protection device action message sent to the monitoring background, it is assessed whether the subway protection can quickly and selectively identify and isolate the faulty section.

[0037] The above-mentioned subway large-area power supply system protection test device expands the voltage source and current source of the relay protection tester through the voltage shunt device and the current shunt device, so as to achieve the purpose of testing all intervals in the subway large-area power supply system with a single relay protection tester; through the state sequence of the relay protection tester and the SPDT control of the current shunt device, the effect of truly simulating the distribution and change of fault voltage and current is achieved; the voltage shunt device and the current shunt device can be flexibly expanded according to the operating mode and the number of intervals of the subway power supply system, and have high applicability.

[0038] Accordingly, please refer to Figure 5 A second aspect of an embodiment of the present invention provides a method for controlling a large-area power supply system protection test device for a subway, which is used to control any of the above-mentioned large-area power supply system protection test devices for a subway, and includes the following steps:

[0039] Step S100, when simulating a fault, setting a plurality of groups of single-pole double-throw tank-opening operation states in the current shunt device according to the location of the fault point and the type of the fault.

[0040] Step S200, predicting the bus voltage of each section and the fault current of each interval according to the test items, and setting the voltage value and current value in the relay protection tester according to the prediction results.

[0041] Step S300, setting the output quantity states of several groups of relay protection testers with contactor coils connected in series in each state sequence.

[0042] Step S400, judging whether the subway protection has identified and isolated the fault section through the action time of the protection device recorded by the relay protection tester and the protection device action message sent to the monitoring module.

[0043] The embodiment of the present invention aims to protect a protection test device for a large-area power supply system of a subway and a control method thereof, including: a relay protection tester, a voltage shunt module, a current shunt module, a protection device under test, and a monitoring module. The voltage shunt module includes: a plurality of groups of contactors, the input ends of the plurality of groups of contactors are connected in parallel to the three-phase voltage at the output end of the relay protection tester, and the output ends thereof are respectively connected to the protection devices under test at each interval on the same bus; the current shunt module includes: a plurality of groups of single-pole double-throw switches connected in series to the current loop of the protection device under test, and the fault ends thereof are short-circuited and connected to the current common end of the relay protection tester; the monitoring module determines whether the subway protection has determined and isolated the faulty section according to the protection device action time recorded by the relay protection tester and the protection device action message received. The above technical scheme has the following effects:

[0044] By using voltage shunt devices and current shunt devices to divide the voltage and current output by a relay protection tester into multiple groups of controllable voltages and currents and apply them to multiple protection devices of each substation in a large area, it is possible to truly simulate the changes in bus voltages and interval currents in different operating modes and locations of the power supply system, as well as faults and protection actions that trip the circuit breaker. This solves the problems of insufficient number of voltage and current sources of the relay protection tester during protection testing of the subway large-area power supply system, inability to truly simulate the distribution and changes of fault voltage and current, the need to constantly replace wiring for different operating modes and different fault points, and low testing efficiency.

[0045] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A protection test device for a large-area power supply system in a subway, characterized in that: include: Relay protection tester, voltage shunt module, current shunt module, tested protection device, monitoring module; The voltage shunt module comprises: a plurality of contactor groups, the input ends of the plurality of contactor groups are connected in parallel to the three-phase voltage of the output end of the relay protection tester, and the output ends thereof are respectively connected to the protection devices to be tested at each interval on the same bus; The current shunt module comprises: a plurality of groups of single-pole double-throw switches connected in series to the current loop of the protection device under test, the fault ends of which are short-circuited and connected to the current common end of the relay protection tester; The monitoring module determines whether the subway protection has determined and isolated the fault section according to the protection device action time recorded by the relay protection tester and the protection device action message received; The protection interval is provided with a simulated circuit breaker; The tripping / closing output of the protection device is connected to the tripping / closing coil of the simulated circuit breaker of the corresponding interval, and the tripping / closing input of the protection device is connected to the tripping / closing contact of the simulated circuit breaker of the corresponding interval; The three-phase main contact input end of the contactor is connected in parallel to the three-phase voltage of the relay protection tester, and the main contact output end is respectively connected to each interval protection device under test connected to the same busbar, one end of the coil of the contactor is short-circuited and then connected to the positive power supply, and the other end of the coil is respectively connected in series with an output of the tester and then connected to the negative power supply; The current output by the relay protection tester is connected in series with the current loop of the protection device under test in each of the intervals in the power supply direction and then connected in series with a single-pole double-throw switch. When the current is connected in series with the single-pole double-throw switch, it is connected from its input end and output from its normal operating end. The fault end of the single-pole double-throw switch is short-circuited and connected to the current common end of the relay protection tester.

2. The protection test device for a large-area power supply system of a subway according to claim 1 is characterized in that: Also includes: A clock source is connected to all the protection devices respectively and sends a clock signal to all the protection devices.

3. A control method for a large-area power supply system protection test device for a subway, characterized in that: The device for controlling the protection test of the large-area power supply system of a subway according to claim 1 or 2 comprises the following steps: When simulating a fault, the operating states of several groups of single-pole double-throw switches are set in the current shunt device according to the location of the fault point and the type of fault; Predict the bus voltage of each section and the fault current of each interval according to the test items, and set the voltage and current values ​​in the relay protection tester according to the prediction results; In each state sequence, a plurality of groups of contactor coils connected in series are arranged to form the output state of the relay protection tester; The action time of the protection device recorded by the relay protection tester and the action message of the protection device sent to the monitoring module are used to determine whether the subway protection has identified and isolated the fault section.

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