Active power distribution network fault simulation experiment platform

Abstract

The utility model discloses an active power distribution network fault simulation experiment platform which comprises a public network power supply module, a line switch module, a power distribution network line section module and a plug panel which are connected in sequence, and a wave recording detection and relay protection module, a fault simulation module, a distributed power supply module and a load module which are connected with the plug panel, the public network power supply module and the line switch module are connected with the plug panel. The public network power supply module comprises a switch control circuit, a power supply side circuit breaker, a control contactor, a transformer and a distribution network side circuit breaker which are connected in sequence; the transformer is connected with an arc suppression coil, and the arc suppression coil is connected with the plug panel. The device is novel and reasonable in design and convenient to operate, realizes simulation experiments of different normal operation modes and different fault types in the active power distribution network by setting different topological structures and adjusting the fault types, realizes acquisition of characteristic signals in faults for fault characteristic signal analysis, and is good in safety performance and high in reliability. And an experimenter can conveniently carry out a simulation experiment.

Description

Technical Field

[0001] This utility model belongs to the field of active power distribution network operation experiment technology, specifically relating to an active power distribution network fault simulation experiment platform. Background Technology

[0002] Distributed photovoltaic (PV) and other new energy power generation technologies are developing rapidly as important sources of renewable and clean electricity. Distributed PV is typically connected to the distribution network via inverters, transforming a single-source distribution network into an active distribution network with multiple sources. With the large-scale integration of these PV inverter-type distributed power sources, the grid connection, operation, and fault protection of new active distribution networks have become research hotspots.

[0003] From the perspectives of scientific research, technological equipment development, engineering design, and operation and maintenance, experimental research is an important way to clarify the operating status of this new type of active distribution network; and the construction of an experimental system platform is the core of experimental research. In particular, the construction of an active distribution network experimental platform is especially important for the study of the operating characteristics and mechanisms of active distribution networks, the feasibility of inverter power supply control and grid connection, and the testing and inspection of fault protection equipment.

[0004] Conducting experiments directly on the power distribution network presents significant challenges. Firstly, connecting experimental equipment requires a system power outage, disrupting user power supply. Secondly, the high voltage levels of actual power grids pose considerable risks, particularly for fault experiments which carry the risk of overcurrent. Therefore, current preliminary theoretical research primarily utilizes digital simulations. Compared to physical experiments, simulations employ digital mathematical models, leading to conclusions that may differ from actual conditions. More importantly, some fault detection devices require laboratory testing before practical application; furthermore, the control methods and protection feasibility of inverters also necessitate experimental verification. Thus, an active power distribution network system experimental platform effectively addresses these issues.

[0005] From the perspective of the characteristics of active power distribution networks, actual systems have different network topologies (such as radial networks and ring networks), inverters have different control methods, access methods and locations, faults have different types, and systems have different operating modes. A practical experimental platform should be able to meet the experimental objectives of different active power distribution networks and easily adapt to combinations and changes in network topology, inverters, and operating modes.

[0006] Therefore, there is an urgent need for an active power distribution network fault simulation experimental platform that is simple in structure, novel and reasonable in design, convenient in operation, and whose network topology, inverter power supply type and access location, operation mode and fault type can be changed according to the user's needs. Summary of the Invention

[0007] The technical problem to be solved by this utility model is to provide an active power distribution network fault simulation experimental platform to address the shortcomings of the prior art. The platform has a simple structure, a novel and reasonable design, and is easy to operate. By setting different topologies and adjusting fault types, it can realize simulation experiments of different normal operating modes and different fault types in the active power distribution network. It can also collect characteristic signals in the fault and perform fault characteristic signal analysis. It has good safety performance, is convenient for experimenters to conduct simulation experiments, is highly practical, and is easy to promote and use.

[0008] To solve the above technical problems, the technical solution adopted by this utility model is: an active power distribution network fault simulation experimental platform, including a public power supply module, a line switch module, a distribution network line segment module and a plug-in panel connected in sequence, as well as a waveform recording and relay protection module, a fault simulation module, a distributed power supply module and a load module connected to the plug-in panel, wherein the public power supply module and the line switch module are both connected to the plug-in panel;

[0009] The public power module includes a switch control circuit for switching on and off the public power supply and emergency stop in case of faults and emergencies, a power-side circuit breaker for switching on and off the public power supply and providing overcurrent protection, a control contactor, a transformer, and a distribution-side circuit breaker for distribution network access, connected in sequence. The transformer is equipped with an arc suppression coil, which is connected to a plug-in panel.

[0010] In the aforementioned active power distribution network fault simulation experimental platform, the arc suppression coil is a variable arc suppression coil with multiple taps, and the multiple taps are respectively connected to multiple sockets on the plug panel.

[0011] The above-mentioned active power distribution network fault simulation experimental platform includes a switch control circuit comprising a control contactor KM0 and an emergency stop button K0. The power supply side circuit breaker is a circuit breaker QF01, the control contactor is contactor KM0, the transformer is transformer T1, and the distribution network side circuit breaker is circuit breaker QF02. The circuit breaker QF01, contactor KM0, transformer T1, and circuit breaker QF02 are connected in sequence and then connected to an ammeter in series and a voltmeter in parallel.

[0012] The aforementioned active power distribution network fault simulation experimental platform includes a line switch module comprising multiple circuit breakers for controlling the access of multiple line segments.

[0013] The aforementioned active power distribution network fault simulation experimental platform includes eight molded case circuit breakers (QF1 to QF8), which are used to control the connection of eight lines (L1 to L8). One end of the main contact of each of the molded case circuit breakers (QF1 to QF8) is connected to multiple sockets on the plug-in panel, and the auxiliary normally open contacts of each of the molded case circuit breakers (QF1 to QF8) are connected to indicator lights (HL1 to HL8).

[0014] The aforementioned active power distribution network fault simulation experimental platform includes a power distribution network line segment module comprising multiple three-phase π-type line models, with both ends of the π-type line models connected to multiple sockets on a plug-in panel.

[0015] The aforementioned active power distribution network fault simulation experimental platform includes a distributed power supply module comprising a PQ-controlled undervoltage protection inverter, a PQ-controlled undervoltage ride-through inverter, and a VF-controlled inverter. Each inverter is connected to multiple sockets on a plug-in panel via connectors as needed, enabling the access of different types of new energy inverters in the active power distribution network.

[0016] The above-mentioned active power distribution network fault simulation experimental platform includes a load module comprising multiple sets of motors and multiple sets of RL-type loads.

[0017] The aforementioned active power distribution network fault simulation experimental platform includes a waveform recording and relay protection module comprising multiple current transformers, multiple voltage transformers, a data acquisition card, a computer, and a relay protection device. When the voltage transformers and current transformers are connected to the relay protection device, they are used to test the relay protection function of the active power distribution network. When the wiring of the plug-in panel passes through the current transformer, the main circuit current is measured. The voltage transformers are connected to the sockets at different positions on the plug-in panel through the wiring terminals to measure the voltage at different positions.

[0018] The aforementioned active power distribution network fault simulation experimental platform includes a fault simulation module for simulating different types of faults. This module comprises a fault main circuit and a fault occurrence control circuit. The different fault types include three-phase short-circuit faults, two-phase-to-phase short-circuit faults, two-phase-to-ground short-circuit faults, and single-phase-to-ground faults. The fault main circuit includes the main contact portion of contactor KM2 and a variable resistor box. The two ends of the main contact of contactor KM2 are connected to the sockets on the plug-in panel, allowing for the simulation of faults at different locations. The variable resistor box includes a three-phase variable resistor and a grounding switch SA2. As needed, it is connected to the sockets of the main contact of contactor KM2 on the plug-in panel via wiring terminals to achieve fault type conversion. The fault occurrence control circuit controls the occurrence of faults and includes an emergency stop button SB2, a fault command switch SA1, a fault indicator light HL9, and the coil portion of contactor KM2. The emergency stop button SB2, fault command switch SA1, and fault indicator light HL9 are connected in series, while contactor KM2 and fault indicator light HL9 are connected in parallel.

[0019] The aforementioned active power distribution network fault simulation experimental platform includes a plug-in panel with multiple sockets. Different connection methods of the sockets enable the selection and access of power distribution network operation mode, network structure, inverter power supply type, fault mode, and test waveform. The sockets include arc suppression coil inductance change sockets, switch port sockets, fault unit connection and type selection sockets, and line segment sockets. The plug-in panel is also equipped with switch on / off indicator lights HL1-HL8, power emergency stop button K0, fault emergency stop button SB2, fault command switch SA1, and fault indicator light HL9.

[0020] This utility model has the following advantages compared with the prior art:

[0021] 1. This utility model has a simple structure and reasonable design. By using connecting wires to connect the plug-in holes of the distribution network line segment module on the plug-in panel, it can realize various required power grid topologies such as radial structure and ring network structure of the distribution network. The operation is simple and convenient.

[0022] 2. This utility model achieves the following: by using connecting wires to connect the plug holes of the distribution network line segment modules on the plug panel, distributed power sources can be connected to the plug holes of the distribution network line segment modules on the plug panel under radial and ring network structures. This allows the inverter power source to be connected to the distribution network at different locations, such as the power supply side of the bus system, the T-shaped connection in the middle of the line, the load end, and different lines. Since the distributed power source uses three different types of inverter power sources, namely PQ-controlled undervoltage protection inverter power source, PQ-controlled low-voltage ride-through inverter power source, and VF-controlled inverter power source, it can also simulate different types of active distribution networks as needed, providing high flexibility.

[0023] 3. This utility model can realize traditional distribution network mode, distribution network mode with distributed power source and microgrid island operation mode by opening and closing QF02 and connecting inverter power supply with different control methods according to actual needs, and has wide applicability.

[0024] 4. This utility model can change the operation mode of the distribution network center point by changing the wiring of the arc suppression coil socket, that is, the neutral point is not connected to ground, the neutral point is grounded through the arc suppression coil, and different compensation degrees (under-compensation, over-compensation, resonance), etc., which is highly practical.

[0025] The five utility models can simulate three-phase short circuits, phase-to-phase short circuits, two-phase ground faults, and single-phase ground faults in active power distribution networks through a fault simulation module, making it convenient to conduct simulation experiments on active power distribution network faults. In emergency situations, it can achieve emergency stop of faults, making the experiment safe, automatic, and convenient.

[0026] 6. Because this utility model can change the access location of distributed power sources, it can not only simulate faults in active distribution networks, but also simulate faults in traditional distribution networks, and can also conduct experiments on active distribution network connection, thus having a wider range of applications.

[0027] 7. This utility model device can accurately simulate phase-to-phase short-circuit faults in active distribution networks, and can change the type of sensor to collect more fault characteristics, providing a basis for protection methods of active distribution networks, improving the safety performance of active distribution network tests, and is reliable and easy to promote and use.

[0028] 8. This utility model can conveniently collect the required experimental data for scientific research, and can also test the performance of protective devices for engineering testing. It has rich functions and high practicality.

[0029] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] Figure 1 This is a circuit block diagram of the present invention;

[0031] Figure 2 This is a circuit block diagram of the public grid power module of this utility model;

[0032] Figure 3 This is the circuit schematic diagram of the public grid power module of this utility model;

[0033] Figure 4 This is the circuit diagram of the power distribution line switch module of this utility model;

[0034] Figure 5 and Figure 6 This is the circuit schematic diagram of the line segment module of this utility model;

[0035] Figure 7 This utility model relates to an inverter power supply module;

[0036] Figure 8 This is the circuit schematic diagram of the load module of this utility model;

[0037] Figure 9 This is the circuit schematic diagram of the waveform recording detection and relay protection module of this utility model;

[0038] Figure 10 The circuit principle of the fault generation module of this utility model;

[0039] Figure 11 This is a diagram of the plug-in panel of this utility model.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1—Public power supply module; 1-1—Switch control circuit; 1-2—Power supply side circuit breaker; 1-3—Control contactor; 1-4—Transformer; 1-5—Distribution network side circuit breaker; 1-6—Arc suppression coil; 1-7—Ammeter; 1-8—Voltmeter; 2—Line switch module; 3—Distribution network line segment module; 4—Distributed power supply module; 5—Load module; 6—Voltage recording and relay protection module; 7—Fault simulation module; 8—Plug-in panel. Detailed Implementation

[0042] like Figure 1 As shown, the active power distribution network fault simulation experimental platform of this utility model includes a public power supply module 1, a line switch module 2, a distribution network line segment module 3 and a plug-in panel 8 connected in sequence, as well as a waveform recording detection and relay protection module 6, a fault simulation module 7, a distributed power supply module 4 and a load module 5 connected to the plug-in panel 8. The public power supply module 1 and the line switch module 2 are both connected to the plug-in panel 8.

[0043] like Figure 2 and Figure 3 As shown, the public power module 1 includes a switch control circuit 1-1 for switching on and off the public power supply and emergency stop in case of faults and emergencies, a power supply side circuit breaker 1-2 for switching on and off the public power supply and providing overcurrent protection, a control contactor 1-3, a transformer 1-4, and a distribution network side circuit breaker 1-5 for distribution network access, connected in sequence. An arc suppression coil 1-6 is connected to the transformer 1-4, and the arc suppression coil 1-6 is connected to the plug-in panel 8.

[0044] By changing the wiring of arc suppression coils 1-6, the power distribution network can operate in various modes, including ungrounded neutral point operation, over-compensated operation, under-compensated operation, and resonant operation with the neutral point grounded via the arc suppression coil.

[0045] In this embodiment, the arc suppression coils 1-6 are variable arc suppression coils with multiple taps, which are respectively connected to multiple sockets on the plug-in panel 8. The magnitude of the arc suppression compensation inductance can be changed by connecting different taps of the arc suppression coils 1-6.

[0046] In this embodiment, the switch control circuit 1-1 includes a control contactor KM0 and an emergency stop button K0. The power supply side circuit breaker 1-2 is a circuit breaker QF01. The control contactor 1-3 is a contactor KM0. The transformer 1-4 is a transformer T1. The distribution network side circuit breaker 1-5 is a circuit breaker QF02. The circuit breaker QF01, contactor KM0, transformer T1, and circuit breaker QF02 are connected in sequence and then connected to an ammeter 1-7 in series and a voltmeter 1-8 in parallel.

[0047] Contactor KM0 and emergency stop button K0 together form the control part for the connection of public power supply to the active distribution network, realizing the switching on and off of public power supply and emergency stop in case of faults and emergencies.

[0048] In this embodiment, the line switch module 2 includes multiple circuit breakers, each used to control the access of multiple line segments.

[0049] In this embodiment, as Figure 4 As shown, the circuit breaker consists of eight molded case circuit breakers QF1 to QF8, which are used to control the connection of eight lines L1 to L8. One end of the main contact of each of the molded case circuit breakers QF1 to QF8 is connected to multiple sockets on the plug-in panel 8. The auxiliary normally open contacts of the molded case circuit breakers QF1 to QF8 are connected to indicator lights HL1 to HL8, which are used to indicate the connection status of lines L1 to L8.

[0050] In this embodiment, as Figure 5 and Figure 6 As shown, the distribution network line segment module 3 includes multiple three-phase π-type line models, with both ends of each π-type line model connected to multiple sockets on the plug-in panel 8. Different line network topologies can be formed through the connections between the sockets, simulating different network configurations; and it can also connect to the load module 5 and the distributed power supply module 4 to enable the access of different inverter power supplies.

[0051] In practice, the number of three-phase π-type line models is 8.

[0052] In this embodiment, as Figure 7 As shown, the distributed power module 4 includes a PQ-controlled undervoltage protection inverter, a PQ-controlled undervoltage ride-through inverter, and a VF-controlled inverter. Each inverter is connected to multiple sockets on the plug panel 8 as needed via wiring terminals to enable the access of different types of new energy inverters in the active power distribution network.

[0053] In specific implementation, the number of PQ-controlled undervoltage protection inverters is 2, the number of PQ-controlled low-voltage ride-through inverters is 2, and the number of VF-controlled inverters is 1.

[0054] In this embodiment, as Figure 8 As shown, the load module 5 includes multiple sets of motors and multiple sets of RL-type loads.

[0055] In specific implementation, the number of motors is 4 sets, and the number of RL type loads is 4 sets.

[0056] In this embodiment, as Figure 9 As shown, the waveform recording and relay protection module 6 includes multiple current transformers, multiple voltage transformers, a data acquisition card, a computer, and a relay protection device. When the voltage transformers and current transformers are connected to the relay protection device, they are used to test the relay protection function of the active power distribution network. When the wiring of the plug panel 8 passes through the current transformer, the main circuit current is measured. The voltage transformers are connected to the sockets at different positions on the plug panel through the wiring terminals to measure the voltage at different positions.

[0057] In specific implementation, the number of current transformers is 13, including current transformers TA1-TA13; the number of voltage transformers is 3, including voltage transformers TV1-TV3; and it can realize the acquisition and recording of up to 16 channels of signals.

[0058] In this embodiment, as Figure 10 As shown, the fault simulation module 7 is used to simulate different types of faults, including a fault main circuit and a fault occurrence control circuit. The different types of faults include three-phase short circuit faults, two-phase phase-to-phase short circuit faults, two-phase ground short circuit faults, and single-phase ground faults. The fault main circuit includes the main contact part of contactor KM2 and a variable resistor box. The two ends of the main contact of contactor KM2 are connected to the socket of the plug panel 8, and the simulation of faults in different locations can be realized through the socket. The variable resistor box includes a three-phase variable resistor and a grounding switch SA2. As needed, it is connected to the socket of the main contact of contactor KM2 on the plug panel through the wiring terminal to realize the conversion of fault types. The fault occurrence control circuit is used to control the occurrence of faults, including a fault emergency stop button SB2, a fault command switch SA1, a fault indicator light HL9, and the coil part of contactor KM2. The fault emergency stop button SB2, the fault command switch SA1, and the fault indicator light HL9 are connected in series, and the contactor KM2 and the fault indicator light HL9 are connected in parallel.

[0059] In this embodiment, as Figure 11As shown, the plug-in panel 8 includes multiple sockets. Different connection methods of the sockets can realize the selection and access of distribution network operation mode, network structure, inverter power supply type, fault mode, and test waveform. The sockets include arc suppression coil inductance change sockets, switch port sockets, fault unit connection and type selection sockets, and line segment sockets. The plug-in panel 8 is also equipped with switch on / off indicator lights HL1-HL8, power emergency stop button K0, fault emergency stop button SB2, fault command switch SA1, and fault indicator light HL9.

[0060] In use, this invention allows for various power grid topologies, such as radial and ring networks, to be achieved by connecting the plug-in holes of the distribution network segment modules on the plug-in panel using connecting cables. With radial and ring network structures implemented, distributed generation can connect to the distribution network segment modules on the plug-in panel via plugs, enabling the inverter to access the distribution network at different locations, including the power supply side of the bus system, T-shaped connections in the middle of the line, near the load end, and on different lines. Because the distributed generation uses three different types of inverters—PQ-controlled undervoltage protection inverters, PQ-controlled low-voltage ride-through inverters, and VF-controlled inverters—it can also simulate different types of active distribution networks as needed. Furthermore, it allows for the switching of QF02 according to actual requirements. It integrates and connects inverters with different control methods to realize traditional distribution network mode, distribution network mode with distributed power source, and microgrid island operation mode; by changing the wiring of the arc suppression coil socket, it realizes the change of the operation mode of the distribution network center point, that is, the center point is not grounded, and the neutral point is grounded through the arc suppression coil with different compensation degrees (undercompensation, overcompensation, resonance), etc.; through the fault simulation module, it can realize three-phase short circuit, phase-to-phase short circuit, two-phase ground short circuit and single-phase ground fault in active distribution network, which can facilitate the simulation experiment of active distribution network faults, and can realize emergency stop in case of fault; because it can change the connection position of distributed power source, it can not only simulate faults of active distribution network, but also simulate faults of traditional distribution network, and can also conduct experiments on active distribution network grid connection.

[0061] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. An active power distribution network fault simulation experimental platform, characterized in that: It includes a public power supply module (1), a line switch module (2), a distribution network line segment module (3) and a plug-in panel (8) connected in sequence, as well as a waveform recording and relay protection module (6), a fault simulation module (7), a distributed power supply module (4) and a load module (5) connected to the plug-in panel (8). The public power supply module (1) and the line switch module (2) are both connected to the plug-in panel (8). The public power supply module (1) includes a switch control circuit (1-1) for opening and closing the public power supply and emergency stop in case of faults and emergencies, a power supply side circuit breaker (1-2) for opening and closing the public power supply and providing overcurrent protection, a control contactor (1-3), a transformer (1-4), and a distribution network side circuit breaker (1-5) for connecting to the distribution network. An arc suppression coil (1-6) is connected to the transformer (1-4), and the arc suppression coil (1-6) is connected to the plug-in panel (8).

2. The active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The arc suppression coil (1-6) is a variable arc suppression coil with multiple taps, and the multiple taps are respectively connected to multiple sockets of the plug panel (8).

3. The active power distribution network fault simulation experimental platform according to claim 2, characterized in that: The switch control circuit (1-1) includes a control contactor KM0 and an emergency stop button K0. The power supply side circuit breaker (1-2) is circuit breaker QF01. The control contactor (1-3) is contactor KM0. The transformer (1-4) is transformer T1. The distribution network side circuit breaker (1-5) is circuit breaker QF02. The circuit breaker QF01, contactor KM0, transformer T1, and circuit breaker QF02 are connected in sequence and then connected to an ammeter (1-7) in series and a voltmeter (1-8) in parallel.

4. The active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The line switch module (2) includes multiple circuit breakers, each used to control the access of multiple line segments.

5. An active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The circuit breaker consists of eight molded case circuit breakers QF1 to QF8, which are used to control the access of eight lines L1 to L8. One end of the main contact of each of the molded case circuit breakers QF1 to QF8 is connected to multiple sockets of the plug panel (8). The auxiliary normally open contacts of the molded case circuit breakers QF1 to QF8 are connected to indicator lights HL1 to HL8.

6. An active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The distribution network line segment module (3) includes multiple three-phase π-type line models, and the two ends of the π-type line models are respectively connected to multiple sockets of the plug panel (8).

7. An active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The distributed power module (4) includes a PQ-controlled undervoltage protection inverter, a PQ-controlled undervoltage ride-through inverter, and a VF-controlled inverter. Each inverter is connected to multiple sockets on the plug panel (8) as needed via a connector to enable different types of new energy inverters to access the active power distribution network.

8. An active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The load module (5) includes multiple sets of motors and multiple sets of RL-type loads.

9. An active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The waveform recording and relay protection module (6) includes multiple current transformers, multiple voltage transformers, a data acquisition card, a computer, and a relay protection device. When the voltage transformers and current transformers are connected to the relay protection device, they are used to test the relay protection function of the active power distribution network. When the wiring of the plug panel (8) passes through the current transformer, the main circuit current is measured. The voltage transformers are connected to the plug holes at different positions on the plug panel through the wiring terminals to measure the voltage at different positions.

10. An active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The fault simulation module (7) is used to simulate different types of faults, including a fault main circuit and a fault occurrence control circuit. The different types of faults include three-phase short circuit faults, two-phase short circuit faults, two-phase ground short circuit faults, and single-phase ground faults. The fault main circuit includes the main contact part of contactor KM2 and a variable resistor box. The two ends of the main contact of contactor KM2 are connected to the socket of the plug panel (8). The simulation of faults in different locations can be realized through the socket. The variable resistor box includes a three-phase variable resistor and a grounding switch SA2. It is connected to the socket of the main contact of contactor KM2 on the plug panel as needed to realize the conversion of fault types. The fault occurrence control circuit is used to control the occurrence of faults, including a fault emergency stop button SB2, a fault command switch SA1, a fault indicator light HL9, and the coil part of contactor KM2. The fault emergency stop button SB2, the fault command switch SA1, and the fault indicator light HL9 are connected in series, and the contactor KM2 and the fault indicator light HL9 are connected in parallel.

11. An active power distribution network fault simulation experimental platform according to claim 1, characterized in that: The plug panel (8) includes multiple sockets. Different connection methods of the sockets can realize the selection and access of distribution network operation mode, network structure, inverter power supply type, fault mode, test waveform selection and access. The sockets include arc suppression coil inductance change socket, switch port socket, fault unit connection and type selection socket and line segment socket. The plug panel (8) is also equipped with switch on / off indicator lights HL1-HL8, power emergency stop button K0, fault emergency stop button SB2, fault command switch SA1 and fault indicator light HL9.

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