Analog device and method of transition resistance under power distribution network cyber-physical system

Abstract

This invention provides a simulation device and method for transition resistance in a distribution network cyber-physical system. The simulation device includes a rectifier module, a switching module, and a control module. The switching module includes multiple simulated loads connected in series. The DC side of the rectifier module is connected to the switching module to provide DC voltage to the switching module. The control module is connected to the switching module and simulates the transition resistance by adjusting the number of simulated loads connected. This invention controls the switching module through the control module, enabling the simulation of not only fixed-value transition resistance but also variable-value transition resistance. It can also reflect the change process of the transition resistance value, and the simulation results are highly accurate. This invention can provide a basis for the simulation of short-circuit faults and the setting design of relay protection devices in a distribution network cyber-physical system.

Description

Technical Field

[0001] This invention relates to the field of power distribution network technology, and specifically to a device and method for simulating transition resistance in a power distribution network cyber-physical system. Background Technology

[0002] When a distribution network experiences a short-circuit fault, such as a single-phase ground fault, a two-phase short-circuit fault, or a three-phase short-circuit fault, a large short-circuit current is generated. By verifying the short-circuit current, a theoretical basis can be provided for the design of the setting values ​​of the distribution network relay protection device, and a reference standard can be provided for the design of the distribution network line capacity.

[0003] Single-phase ground faults are the most frequent faults in distribution networks. However, when a single-phase ground fault occurs in a distribution network, the transition resistance at the short-circuit point may be a fixed value or a variable value. Improving the simulation accuracy of fixed-value transition resistances can provide a basis for the design of setting values ​​for distribution network relay protection devices and the design of distribution network line capacity. For distribution network cable lines, the process from insulation damage to final insulation breakdown is usually a long and slow one. During this process, the transition resistance changes when a single-phase ground fault occurs in the cable line. Before insulation breakdown, the transition resistance is relatively high, and once insulation breakdown occurs, the resistance decreases rapidly, showing a phenomenon of initially high and then low resistance.

[0004] Existing fault simulation methods can only simulate transition resistors with fixed resistance values, and only reflect the resistance values ​​at different times in a step-like manner, failing to reflect the change process of the transition resistor value, resulting in low accuracy of simulation results. Summary of the Invention

[0005] To overcome the shortcomings of low accuracy in simulation results in the prior art, the present invention provides a simulation device for transition resistance in a distribution network cyber-physical system, including a rectifier module, a switching module, and a control module; the switching module includes multiple simulated loads connected in series.

[0006] The DC side of the rectifier module is connected to the switching module and is used to provide DC voltage to the switching module;

[0007] The control module is connected to the switching module, and it simulates the transition resistance by simulating the number of loads being switched on.

[0008] Each simulated load includes a load resistor and a bidirectional thyristor switch; the load resistor and the bidirectional thyristor switch are connected in parallel;

[0009] Furthermore, the load resistor value is the same in each simulated load.

[0010] The rectifier module includes a filter inductor, an H-bridge structure, a DC support capacitor, and a voltage sensor PT1;

[0011] The filter inductor is located on the AC side of the H-bridge structure, and the DC support capacitor and voltage sensor PT1 are both located on the DC side of the H-bridge structure.

[0012] The voltage sensor PT1 is used to collect the effective value of the DC voltage on the rectifier module.

[0013] It also includes a power module;

[0014] The power supply module is connected to the AC side of the rectifier module and is used to provide AC voltage to the rectifier module.

[0015] The power module includes an AC power supply, a voltage sensor PT2, and a current sensor CT.

[0016] Both the voltage sensor PT2 and the current sensor CT are located at the output end of the AC power supply.

[0017] The voltage sensor PT2 is used to collect the effective value of the voltage output by the AC power supply;

[0018] The current sensor CT is used to collect the effective value of the current output by the AC power supply.

[0019] The effective value of the AC power output voltage collected by voltage sensor PT2 is less than the effective value of the DC side voltage of the rectifier module collected by voltage sensor PT1.

[0020] On the other hand, the present invention also provides a method for simulating transition resistance in a distribution network cyber-physical system, comprising:

[0021] The rectifier module determines the equivalent load resistance value as seen from the load end of the rectifier module based on the value of the transition resistance to be simulated.

[0022] The control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thereby simulating the transition resistance.

[0023] The equivalent load resistance value viewed from the load terminal of the rectifier module is determined by the following formula:

[0024]

[0025] In the formula, R load R is the resistance value of the equivalent load resistance seen from the load terminal of the rectifier module. S U is the resistance value of the transition resistor to be simulated. dc Voltage sensor PT1, installed on the DC side of the rectifier module, collects the effective value of the DC voltage on the rectifier module. SThe voltage sensor PT2, installed at the output terminal of the power module, collects the effective value of the voltage output by the power module, and U S <U dc .

[0026] When simulating a transition resistance with a fixed resistance value, the control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thereby simulating the transition resistance, including:

[0027] Based on the number of load resistors connected, the control module sends control commands to the corresponding bidirectional thyristor switches in the switching module through the distribution network cyber-physical system, so that the bidirectional thyristor switches are completely turned off.

[0028] When simulating a variable resistance transition resistor, the control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thereby simulating the transition resistor, including:

[0029] Based on the number of load resistors connected, the control module sends control commands to the corresponding bidirectional thyristor switches in the switching module through the distribution network cyber-physical system, so that the bidirectional thyristor switches are completely turned off.

[0030] The control module sends control commands to the corresponding bidirectional thyristor switches in the switching module based on the load resistor's activation time, causing the bidirectional thyristor switches to change from being completely off to being completely on.

[0031] The technical solution provided by this invention has the following beneficial effects:

[0032] The simulation device for transition resistance in a distribution network cyber-physical system provided by this invention includes a rectifier module, a switching module, and a control module. The switching module includes multiple simulated loads connected in series. The DC side of the rectifier module is connected to the switching module to provide DC voltage to the switching module. The control module is connected to the switching module and simulates the transition resistance by controlling the number of simulated loads connected. This invention controls the switching module through the control module to simulate the transition resistance with fixed or variable values, which can reflect the change process of the transition resistance value and has high simulation accuracy.

[0033] The switching module in this invention uses multiple bidirectional thyristor switches connected in series, which can not only simulate the fixed resistance transition resistance, but also realize the simulation of the variable resistance transition resistance.

[0034] The technical solution provided by this invention provides a basis for simulating short-circuit faults and setting design of relay protection devices in the cyber-physical system of distribution networks. Attached Figure Description

[0035] Figure 1This is a block diagram of a simulation device for transition resistance in a distribution network cyber-physical system according to an embodiment of the present invention;

[0036] Figure 2 This is a structural diagram of a simulation device for transition resistance in a distribution network cyber-physical system according to an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the control strategy of the rectifier module controller in an embodiment of the present invention;

[0038] Figure 4 This is a flowchart of the simulation method for transition resistance in the cyber-physical system of the distribution network in this embodiment of the invention;

[0039] Figure 5 This is a schematic diagram of a bidirectional thyristor switch switching the load resistor when simulating a fixed resistance transition resistor and needing to apply a load resistor in an embodiment of the present invention.

[0040] Figure 6 This is a schematic diagram of a bidirectional thyristor switch switching the load resistor when simulating a fixed resistance transition resistor and not requiring the load resistor to be applied, as described in an embodiment of the present invention.

[0041] Figure 7 This is a schematic diagram of a bidirectional thyristor switch switching the load resistor when simulating a variable resistance transition resistor and requiring the load resistor to be applied in an embodiment of the present invention.

[0042] Figure 8 This is a schematic diagram of a bidirectional thyristor switch switching the load resistor when simulating a variable resistance transition resistor and not requiring the load resistor to be applied, as described in an embodiment of the present invention.

[0043] Figure 9 This is a voltage waveform diagram of the power module output when a fixed resistance of 300Ω is simulated in an embodiment of the present invention.

[0044] Figure 10 This is a current waveform diagram of the power module output when a fixed resistance of 300Ω is simulated in an embodiment of the present invention.

[0045] Figure 11 This is a waveform diagram of the DC side voltage of the rectifier module when a fixed resistance of 300Ω is used as a transition resistor in an embodiment of the present invention. Detailed Implementation

[0046] The present invention will now be described in further detail with reference to the accompanying drawings.

[0047] Example 1

[0048] Embodiment 1 of the present invention provides a simulation device for transition resistance in a distribution network cyber-physical system (CPS), such as... Figure 1As shown, it includes a rectifier module, a switching module, and a control module; the switching module includes multiple analog loads connected in series.

[0049] The DC side of the rectifier module is connected to the switching module to provide DC voltage to the switching module;

[0050] The control module is connected to the switching module.

[0051] The control module simulates the transition resistance by simulating the number of loads being applied.

[0052] The structural diagram of the simulation device for transition resistance in the cyber-physical system of the power distribution network is shown below. Figure 2 As shown, Figure 2 Middle,U s I represents the effective value of the voltage output by the power module. s PT2 is the effective value of the current output by the power module, CT is a voltage sensor located at the AC power output terminal, CT is a current sensor located at the AC power output terminal, PT1 is a voltage sensor located on the DC side of the rectifier module, and L is the effective value of the current output by the power module. f The filter inductor of the rectifier module, IGBT1, IGBT2, IGBT3, and IGBT4 form the H-bridge structure in the rectifier module, C is the DC support capacitor located on the DC side of the rectifier module, and U... dc I is the voltage on the DC side of the rectifier module. load For the current flowing through the switching module, R A R B R C R D R E For load resistance; SCR A1 SCR B1 SCR C1 SCR D1 SCR E1 This is a bidirectional thyristor switch. MN is the AC side of the rectifier module, and PQ is the DC side of the rectifier module. In Embodiment 1 of this invention, L f Take 10mH, C takes 2mF, R A R B R C R D R E Using 300Ω for all values, it can simulate a fixed transition resistance from 0 to 1500Ω, or it can simulate a variable transition resistance within this range in any way.

[0053] like Figure 2As shown, each simulated load includes a load resistor and a bidirectional thyristor switch; the load resistor and the bidirectional thyristor switch are connected in parallel; and the load resistor in each simulated load has the same resistance value. That is, the switching module includes multiple load resistors and multiple bidirectional thyristor switches. The multiple load resistors are connected in series to form a resistor branch, and the multiple bidirectional thyristor switches are connected in series to form a switch branch. Each load resistor is connected in parallel with one bidirectional thyristor switch. After the resistor branch and the switch branch are connected in parallel, they are connected to the DC side of the rectifier module. In Embodiment 1 of this invention, R is provided. A R B R C R D R E There are a total of 5 load resistors, and SCR is also set. A1 SCR B1 SCR C1 SCR D1 SCR E1 There are a total of 5 bidirectional thyristor switches.

[0054] Because the switching module uses multiple bidirectional thyristor switches connected in series, it can not only simulate the fixed resistance transition resistance, but also simulate the variable resistance transition resistance.

[0055] The rectifier module includes a filter inductor, an H-bridge structure, a DC support capacitor, and a voltage sensor PT1;

[0056] The filter inductor is located on the AC side of the H-bridge structure, and the DC support capacitor and voltage sensor PT1 are both located on the DC side of the H-bridge structure.

[0057] Voltage sensor PT1 is used to collect the effective value of the DC voltage on the rectifier module.

[0058] The simulation device for transition resistance in the cyber-physical system of the distribution network provided in Embodiment 1 of the present invention further includes a power supply module; the power supply module is a power supply for a single-phase line of the distribution network or a simulated distribution network, and the power supply module is connected to the AC side of the rectifier module to provide AC voltage to the rectifier module.

[0059] The power module includes an AC power supply, a voltage sensor PT2, and a current sensor CT;

[0060] Both the voltage sensor PT2 and the current sensor CT are located at the output of the AC power supply.

[0061] The voltage sensor PT2 is used to collect the effective value of the voltage output by the AC power supply;

[0062] The current sensor CT is used to acquire the effective value of the current output by the AC power supply.

[0063] The effective value of the AC power output voltage collected by voltage sensor PT2 is less than the effective value of the DC side voltage of the rectifier module collected by voltage sensor PT1.

[0064] In Embodiment 1 of this invention, the rectifier module adopts a control strategy of DC voltage outer loop + current inner loop, such as... Figure 3 As shown, Figure 3 middle, Indicates the DC voltage setting value, i d and i q They represent I respectively S d-axis current and q-axis current in a synchronously rotating coordinate system along the dq axes and Representing i respectively d and i q The setting value, setting To enable the rectifier module to operate in unity power factor rectification mode, U sm U represents the peak value of the AC input voltage of the rectifier module. d and U q They represent U respectively S The d-axis and q-axis voltages are located in a synchronously rotating coordinate system. Trigger pulses for IGBT1, IGBT2, IGBT3, and IGBT4 are output via an SPWM modulation stage.

[0065] Example 2

[0066] With the construction of smart distribution networks and ubiquitous power Internet of Things (IoT), a large number of sensing devices, computing units, control systems, and communication networks are integrated with the distribution physical network, forming a distribution network cyber-physical system (CPS). The characteristics of the distribution network CPS include state awareness, real-time analysis, precise control, and scientific processing. Embodiment 2 of this invention provides a method for simulating the transition resistance in a distribution network CPS. This method can simulate the resistance value of the transition resistance in the distribution network CPS, and it can simulate not only transition resistances with fixed resistance values ​​but also transition resistances with variable resistance values.

[0067] The specific flowchart of the simulation method for transition resistance in the cyber-physical system of the distribution network provided in Embodiment 2 of the present invention is as follows: Figure 4 As shown, the specific process is as follows:

[0068] S101: Rectification is based on the value of the transition resistor to be simulated, which determines the equivalent load resistance value seen from the load end of the rectifier module.

[0069] S102: The control module controls the switching module based on the resistance value of the equivalent load resistance seen from the load end of the rectifier module, thereby simulating the transition resistance.

[0070] The equivalent load resistance seen from the load terminal of the rectifier module is determined by the following formula:

[0071]

[0072] In the formula, R load R is the resistance value of the equivalent load resistance seen from the load terminal of the rectifier module. S U is the resistance value of the transition resistor to be simulated. dc Voltage sensor PT1, installed on the DC side of the rectifier module, collects the effective value of the DC voltage on the rectifier module. S The voltage sensor PT2, installed at the output terminal of the power module, collects the effective value of the voltage output by the power module, and U S <U dc .

[0073] When simulating a fixed-value transition resistance (overhead line), the control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thus simulating the transition resistance, including:

[0074] Based on the number of load resistors connected, the control module sends control commands to the corresponding bidirectional thyristor switches in the switching module through the distribution network cyber-physical system, so that the bidirectional thyristor switches are completely turned off.

[0075] Specifically, the control module selects the number of load resistors to be connected. When load resistors need to be connected, the control module, based on the number of load resistors to be connected, sends control commands to the corresponding bidirectional thyristor switches in the switching module through the distribution network cyber-physical system. Specifically, the controller sets the trigger angle of the bidirectional thyristor switches connected in parallel across the two ends of the bidirectional thyristor switches to 180°, so that the bidirectional thyristor switches are completely turned off. Figure 5 As shown, when the number of load resistors that do not need to be connected is 0, the controller sets the trigger angle of the bidirectional thyristor switch connected in parallel across the two ends of the bidirectional thyristor switch to 0°, meaning the bidirectional thyristor switch is fully turned on. Figure 6 As shown, Figure 5 and Figure 6 In this context, α is the thyristor firing angle, and n = A, B, C, D, E.

[0076] When simulating a variable resistance transition resistor (cable line), the control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thereby simulating the transition resistance, including:

[0077] Based on the number of load resistors connected, the control module sends control commands to the corresponding bidirectional thyristor switches in the switching module through the distribution network cyber-physical system, so that the bidirectional thyristor switches are completely turned off.

[0078] The control module sends control commands to the corresponding bidirectional thyristor switches in the switching module based on the load resistor's activation time, causing the bidirectional thyristor switches to change from being completely off to being completely on.

[0079] Specifically: The number and timing of load resistor activation are selected. When load resistors need to be activated, the control module, based on the number of load resistors activated, sends control commands to the corresponding bidirectional thyristor switches in the switching module via the distribution network cyber-physical system. That is, the controller sets the firing angle of the bidirectional thyristor switches connected in parallel across the two ends of the bidirectional thyristor switches to 180°, causing the bidirectional thyristor switches to be completely off. The control module then sends control commands to the corresponding bidirectional thyristor switches in the switching module based on the timing of load resistor activation. That is, the controller sets the firing angle of the bidirectional thyristor switches to change from 180° to 0° at the transition time point, meaning the bidirectional thyristor switches change from completely off to completely on. Figure 7 As shown; when the number of load resistors that do not need to be connected is 0, the control module issues a control command to the corresponding bidirectional thyristor switch in the switching module based on the connection time of the load resistors. That is, the controller sets the firing angle of the bidirectional thyristor switch connected in parallel across the two ends of the bidirectional thyristor switch to 0°, meaning the bidirectional thyristor switch is fully turned on. According to the required simulated transition time, the controller sets the firing angle of the bidirectional thyristor switch to change from 0° to 180° at the transition time point, meaning the bidirectional thyristor switch changes from fully turned on to fully turned off. Figure 8 As shown. Figure 7 and Figure 8 In this context, α is the thyristor firing angle, and t r Let n be the transition time, where n = A, B, C, D, E.

[0080] To verify the effectiveness of the simulation method for transition resistance in the distribution network cyber-physical system provided in Embodiment 2 of the present invention, U is taken as... s Pick U dc Using a 10kV voltage, two scenarios were selected: a fixed-resistance transition resistor simulation and a variable-resistance transition resistor simulation, to simulate the control effect of the invented method. Simultaneously, based on... It can be seen that, under the given scenario, R s and R load satisfy

[0081] (1) Simulate a fixed-value transition resistor and set R. s =300Ω. According to It can be seen that R should be set. load =900Ω. Choose to input R A R B and R C , will R A R B and R CThe trigger angle of the bidirectional thyristor switches at both ends is set to 180°; R D and R E When not in operation, the trigger angle of the bidirectional thyristor switches at both ends is set to 0°. The voltage and current waveforms of the power supply module output and the DC-side voltage waveform of the rectifier module are shown below. Figure 9 , Figure 10 and Figure 11 As shown, Figures 9-11 In the middle, the horizontal axis represents time, from... Figures 9-11 It can be seen that the rectifier module operates in unity power factor rectification mode, and the average DC side voltage of the rectifier module is the set value of 10kV. dc The double power frequency fluctuation is due to the H-bridge rectifier being a single-phase circuit, which generates double frequency power during operation; this is a normal phenomenon. s and I s In phase, I s The peak value is approximately 27.19 A. Since the H-bridge rectifier operates in unity power factor rectification mode, the peak value can be calculated based on the simulation results. Consistent with the theoretical results, the simulation of a fixed-value transition resistor was successfully achieved.

[0082] (2) Simulate a variable resistance transition resistor and set R. s The Ω is changed from 500Ω to 100Ω, with a change interval of 100Ω and a transition time of 1 second. According to... It can be seen that setting R load The Ω is changed from 1500Ω to 300Ω, with a change interval of 300Ω and a transition time of 1 second.

[0083] Simulation time 0s~1s, R s =500Ω, R A R B R C R D and R E All are engaged, and the trigger angle of the bidirectional thyristor switches at both ends is set to 180°;

[0084] Simulation time 1s~2s, R s =400Ω, R A R B R C R D The bidirectional thyristor switching trigger angle at both ends is set to 180°, R E When not in use, the trigger angle of the bidirectional thyristor switches at both ends is set to 0°;

[0085] Simulation time 2s~3s, R s =300Ω, R A R B RC The bidirectional thyristor switching trigger angle at both ends is set to 180°, R D and R E When not in use, the trigger angle of the bidirectional thyristor switches at both ends is set to 0°;

[0086] Simulation time 3s~4s, R s =200Ω, R A R B The bidirectional thyristor switching trigger angle at both ends is set to 180°, R C R D and R E When not in use, the trigger angle of the bidirectional thyristor switches at both ends is set to 0°;

[0087] Simulation time 4s~5s, R s =100Ω, R A The bidirectional thyristor switching trigger angle at both ends is set to 180°, R B R C R D and R E When not in use, the trigger angle of the bidirectional thyristor switches at both ends is set to 0°.

[0088] The rectifier module operates in unity power factor rectification mode, U s and I s In phase. Since the H-bridge rectifier operates in unity power factor rectification mode, the following can be calculated based on simulation results:

[0089] During the period from 0s to 1s, I s The peak value was 16.53A.

[0090] During 1s to 2s, I s The peak value was 20.63A.

[0091] During 2s to 3s, I s The peak value was 27.19A.

[0092] During the 3s to 4s interval, I s The peak value was 40.94A.

[0093] At 4s to 5s, I s The peak value is 81.76A.

[0094] Consistent with the theoretical results, the simulation of the transition resistance with varying resistance values ​​was achieved.

[0095] For ease of description, the various parts of the device described above are divided into modules or units according to their functions. Of course, in implementing this application, the functions of each module or unit can be implemented in one or more software or hardware components.

[0096] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0097] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0098] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0099] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of the present invention by referring to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the present invention pending approval.

Claims

1. A method for simulating transition resistance in a distribution network cyber-physical system, characterized in that, include: The rectifier module determines the equivalent load resistance value as seen from the load end of the rectifier module based on the value of the transition resistance to be simulated. The control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thus simulating the transition resistance; the value of the equivalent load resistance seen from the load end of the rectifier module is determined by the following formula: In the formula, This is the resistance value of the equivalent load resistance seen from the load side of the rectifier module. The resistance value of the transition resistor to be simulated is... A voltage sensor PT1, installed on the DC side of the rectifier module, collects the effective value of the DC voltage on the rectifier module. The voltage sensor PT2, installed at the output terminal of the power module, collects the effective value of the voltage output by the power module, and ; The simulation device for implementing the simulation method includes a rectification module, a switching module, and a control module; the switching module includes multiple simulated loads connected in series. The DC side of the rectifier module is connected to the switching module and is used to provide DC voltage to the switching module; When simulating a transition resistance with a fixed resistance value, the control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thereby simulating the transition resistance, including: Based on the number of load resistors connected, the control module sends control commands to the corresponding bidirectional thyristor switches in the switching module through the distribution network cyber-physical system, so that the bidirectional thyristor switches are completely turned off. When simulating a variable resistance transition resistor, the control module controls the switching module based on the equivalent load resistance seen from the load end of the rectifier module, thereby simulating the transition resistor, including: Based on the number of load resistors connected, the control module sends control commands to the corresponding bidirectional thyristor switches in the switching module through the distribution network cyber-physical system, so that the bidirectional thyristor switches are completely turned off. The control module sends control commands to the corresponding bidirectional thyristor switches in the switching module based on the load resistor's input time, causing the bidirectional thyristor switches to change from being completely off to being completely on. The rectifier module includes a filter inductor, an H-bridge structure, a DC support capacitor, and a voltage sensor PT1; The filter inductor is located on the AC side of the H-bridge structure, and the DC support capacitor and voltage sensor PT1 are both located on the DC side of the H-bridge structure. The voltage sensor PT1 is used to collect the effective value of the DC voltage on the rectifier module.

2. The method for simulating transition resistance in a distribution network cyber-physical system according to claim 1, characterized in that, Each simulated load includes a load resistor and a bidirectional thyristor switch; the load resistor and the bidirectional thyristor switch are connected in parallel; Furthermore, the load resistor value is the same in each simulated load.

3. The method for simulating transition resistance in a distribution network cyber-physical system according to claim 1, characterized in that, The power module includes an AC power supply, a voltage sensor PT2, and a current sensor CT. Both the voltage sensor PT2 and the current sensor CT are located at the output end of the AC power supply. The voltage sensor PT2 is used to collect the effective value of the voltage output by the AC power supply; The current sensor CT is used to collect the effective value of the current output by the AC power supply.

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