Paralleling reactor overvoltage analogue simulation method, system, equipment and medium

Abstract

The invention discloses a shunt reactor overvoltage simulation method, system and device and a medium, and belongs to the field of shunt reactor overvoltage simulation, and the method comprises the following steps: S1, building a vacuum circuit breaker simulation model based on an ATP-EMTP software platform by considering a breaker on-off process, a medium dynamic insulation strength recovery process and an arc reignition judgment mechanism; s2, establishing a paralleling reactor simulation model by utilizing an ATP-EMTP software platform and combining system parameters based on the vacuum circuit breaker simulation model; and S3, simulating behaviors of a vacuum circuit breaker by using the vacuum circuit breaker simulation model, performing first open phase continuous reignition, equivalent cutoff simulation and continuous reignition to equivalent cutoff simulation on the shunt reactor simulation model, and outputting a simulation result. By adopting the shunt reactor overvoltage analogue simulation method, system and equipment and the medium, the main cause of overvoltage is revealed by performing analogue simulation on the on-off process of the vacuum circuit breaker.

Description

Technical Field

[0001] The present invention relates to the technical field of shunt reactor overvoltage simulation, and in particular to a shunt reactor overvoltage simulation method, system, equipment and medium. Background Art

[0002] Shunt reactors are mainly used in power systems to compensate for capacitive reactive power of lines and stabilize system voltage. Since the load of the power system changes over time, shunt reactors must be frequently switched on and off to compensate for reactive power. However, during the switching process of shunt reactors, overvoltage may occur, which poses a threat to the safe operation of the power system.

[0003] In the distribution network, vacuum circuit breakers are generally selected for switching shunt reactors. The advantages of vacuum circuit breakers are high electrical recovery strength, good arc extinguishing ability and good frequent operation characteristics, etc. However, vacuum circuit breakers also have a current cutoff effect, which can easily cause overvoltage problems, seriously threatening the insulation safety of equipment and affecting the safe and stable operation of the power system.

[0004] In recent years, when using vacuum circuit breakers to cut off 35kV shunt reactors, there have been many failures such as reactor switch cabinet burnout or internal breakdown caused by operating overvoltage. Therefore, the existing technology has conducted the following research on overvoltage line type:

[0005] Previous studies have mostly believed that the overvoltage phenomenon is caused by the cutoff during the breaking process, and when the cutoff value is near 3A, the cutoff phenomenon of the vacuum circuit breaker has a relatively small impact on the overvoltage amplitude, but as the cutoff value increases, the cutoff overvoltage multiple increases significantly. And when the system is an empty busbar with no outgoing lines, the busbar side will oscillate greatly due to the small capacitance to ground and the resistance to the re-ignition caused by the breaking. At the same time, due to the instability of the vacuum arc, the cutoff phenomenon is difficult to avoid in the process of breaking all small current loads, and the current cutoff value is less than 5A, which has little impact on the recovery voltage of the break at both ends of the circuit breaker, so it is not the root cause of the subsequent serious overvoltage.

[0006] In summary, reignition is inevitable, but the reignition overvoltage caused by reignition of a phase current is not strong. Repeated reignition will lead to continuous replenishment of energy and cause voltage rise effect. However, the overvoltage of the other two phases relative to the ground and between the phases is not large at this time, which cannot explain some phase-to-phase overvoltage accidents.

[0007] At present, the cause of overvoltage in 35kV shunt reactor is explained as repeated reignition of the first-opened phase, which then causes equivalent current-cutting overvoltage in the next two phases (the currents of each phase differ by 120°, so when the circuit breaker is commanded to open at a certain moment, there must be a phase current that crosses zero first and extinguishes the arc. This phase is called the first-opened phase, and the two phases that subsequently cross zero are called the next-opened phases). The reignition of the first-opened phase is due to the fact that the growth rate of the insulation strength at both ends of the vacuum circuit breaker is much lower than the rising rate of the break recovery voltage.

[0008] For example, if Figure 1 As shown in the figure, the current of the first phase B passes through zero within 575ms-576ms and then reignites for about 3.5ms, and the voltage step-up effect brought by the reignition of the first phase B is very significant. With the repeated reignition, the oscillation becomes more and more intense. At this time, although the A and C phases have not passed zero, the high-frequency transient current is coupled to the current of the next two phases A and C through the phase-to-phase coupling, so the high-frequency oscillation of the current also occurs. At this time, when the high frequency passes through the zero point, the circuit breaker extinguishes the arc in advance, which leads to the situation that the power frequency current of the next two phases has not passed zero, but is forced to be disconnected. At this time, the magnetic field energy of the cut-off value of the A and C phases will be converted into the electric field energy of the capacitance to the ground on the parallel resistance side, so when the cut-off value is in an extreme situation, the overvoltage is very serious.

[0009] In summary, the mechanism of equivalent cutoff overvoltage is: when the first phase is reignited, the transient current is superimposed on the current of the last two phases that has not yet passed zero due to the coupling between the three phases. After the reignition occurs, the intensity of the break voltage increases, and the transient oscillation continues to increase, causing the current of the last two phases to have a high-frequency zero-crossing point. The circuit breaker can break the high-frequency current after continuous processing, so the high-frequency current is cut off, and the effect of its overvoltage is similar to the power frequency cutoff effect of the circuit breaker. However, for the circuit breaker, this cutoff is the high-frequency current zero-crossing arc extinguishing, and there is no power frequency cutoff. And because the break is open, the current only oscillates between the capacitor and the reactance inductor on the parallel side, and energy is exchanged, thus producing the same effect as the cutoff overvoltage, which is called the equivalent cutoff overvoltage.

[0010] However, since the circuit breaker can break down hundreds of times in a few milliseconds, it is impossible to use a simple switch model to simulate the continuous breakdown process of the load. Summary of the invention

[0011] The purpose of the present invention is to provide a method, system, device and medium for simulating overvoltage of a shunt reactor to solve the above-mentioned technical problems.

[0012] To achieve the above object, the present invention provides a shunt reactor overvoltage simulation method, comprising the following steps:

[0013] S1. Considering the circuit breaker breaking process, the dielectric dynamic insulation strength recovery process, and the arc restrike judgment mechanism, a vacuum circuit breaker simulation model is constructed based on the ATP-EMTP software platform;

[0014] S2. Using the ATP-EMTP software platform, and based on the vacuum circuit breaker simulation model constructed in step S1 and combining system parameters, establish a shunt reactor simulation model;

[0015] S3. Use the vacuum circuit breaker simulation model constructed in step S1 to simulate the behavior of the vacuum circuit breaker, perform first-phase continuous re-ignition, equivalent cutoff simulation and continuous re-ignition to equivalent cutoff simulation on the shunt reactor simulation model described in step S2, and output the simulation results.

[0016] Preferably, the vacuum circuit breaker simulation model described in step S1 includes a MODEL module and a SW-TACS switch; wherein the MODEL module is used to judge the behavior of the simulated circuit breaker under different working conditions through input quantities, and the SW-TACS switch is used to simulate the operation of the actual circuit breaker based on the switch control signal output by the MODEL module;

[0017] The input quantities of the MODEL module are the voltage across the vacuum circuit breaker, the current flowing through the vacuum circuit breaker, the current zero-crossing judgment, and the rate of change of the current with respect to time. The data output quantities of the MODEL module include the break recovery voltage and the break dielectric insulation strength. The MODEL module also outputs a switch control signal for controlling the closing and opening of the SW-TACS switch.

[0018] Preferably, in step S1, the ATP-EMTP software platform is used to establish the simulation of zero-crossing breaking and arc restrike of the vacuum circuit breaker, and the control and switch programs are written in Fortran language to obtain the simulation model of the vacuum circuit breaker and simulate the working process of the vacuum circuit breaker.

[0019] Preferably, the shunt reactor simulation model described in step S2 includes a 35kV bus, an operating line connected to the 35kV bus, and the vacuum circuit breaker simulation model, shunt reactor and lightning arrester described in step S1 connected to the 35kV bus in sequence, wherein both ends of the vacuum circuit breaker simulation model are grounded via distributed capacitors, and the vacuum circuit breaker is connected to the shunt reactor via a cable;

[0020] The system parameters are as follows: Shunt reactor: rated voltage 35kV, rated capacity 3.34Mvar, inductance per phase 380mH, winding resistance 1.2Ω;

[0021] Cable: single-core cable, length 100m, inductance per unit length 0.38μH / m, single-phase capacitance to ground 22nF;

[0022] Lightning arrester: zinc oxide lightning arrester, voltage level 35kV, rated voltage 51kV, DC 1mA reference voltage 75.3kV.

[0023] Preferably, step S3 specifically includes the following steps:

[0024] S31, using the MODEL module to issue a disconnection command;

[0025] S32, determine whether the current I flowing through the vacuum circuit breaker is less than the cut-off current I mar If yes, it indicates that the vacuum circuit breaker starts to break, and the process goes to step S33; otherwise, the process goes to wait;

[0026] S33, the vacuum circuit breaker enters the breaking state, the arc gap of the vacuum circuit breaker is transformed into an insulating medium, a piecewise fitting function between the vacuum circuit breaker breaking time and the dynamic insulation strength is constructed, and then the zero-crossing time is input into the piecewise fitting function to obtain the dynamic insulation strength u d ;

[0027] S34. Determine the dynamic insulation strength u d Is it less than the break recovery voltage u f If yes, the vacuum circuit breaker is closed to simulate the continuous re-ignition and equivalent cutoff of the first-open phase, otherwise the vacuum circuit breaker enters the breaking state described in step S33;

[0028] S35, determine whether the breaking condition is met, if so, enter the breaking state described in step S33, and simulate continuous re-ignition to equivalent cutoff in this process, if not, maintain the closed state.

[0029] Preferably, the piecewise fitting function expression in step S33 is as follows:

[0030]

[0031] Where, t d Indicates the breaking time of the vacuum circuit breaker in ms.

[0032] Preferably, the breaking condition described in step S35 includes simultaneously satisfying the current zero-crossing condition, the high-frequency current zero-crossing arc-extinguishing capability condition and the minimum arcing time condition;

[0033] The current zero-crossing condition is as follows: Collect the current signal I flowing through the vacuum circuit breaker at time t t , and collect the current signal I output after a delay of Δt t-Δt , if the current I at time t t ×I t-Δt <0, the current is judged to be zero-crossing;

[0034] The conditions for the high-frequency current zero-crossing arc extinguishing capability are as follows: If the rate of change of the current flowing through the Where λ represents the set threshold;

[0035] The minimum arcing time condition is as follows: T>T s , where T s is the minimum arcing time, and T is the arcing time.

[0036] A shunt reactor overvoltage simulation system is used to execute a shunt reactor overvoltage simulation method, which includes a parameter setting module, a simulation model building module, a data acquisition module and a simulation result output display module;

[0037] Among them, the parameter setting module is used to set the model parameters;

[0038] The simulation model building module is used to build a shunt reactor simulation model according to the set model parameters;

[0039] The data acquisition module is used to collect simulation results of the shunt reactor simulation model;

[0040] The simulation result output display module is used to output and display the simulation results.

[0041] A computer device comprises a memory, a processor and a computer program stored in the memory and running on the processor. When the processor executes the computer program, a method for simulating overvoltage of a shunt reactor is implemented.

[0042] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements a method for simulating overvoltage of a shunt reactor.

[0043] Therefore, the present invention adopts the above-mentioned shunt reactor overvoltage simulation method, system, device and medium, which has the following beneficial effects:

[0044] By simulating the opening and closing process of the vacuum circuit breaker, the main causes of overvoltage are revealed, thereby revealing the overvoltage generation mechanism of the 35kV shunt reactor during the switching process, providing reliable support for subsequent research.

[0045] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is the equivalent cut-off waveform diagram of a power supply company;

[0047] Figure 2 A flow chart of a shunt reactor overvoltage simulation method according to the present invention;

[0048] Figure 3A shunt reactor simulation model configuration diagram of a shunt reactor overvoltage simulation method of the present invention;

[0049] Figure 4 A schematic diagram of a shunt reactor simulation model of a shunt reactor overvoltage simulation method of the present invention;

[0050] Figure 5 A schematic diagram of a vacuum circuit breaker simulation model of a shunt reactor overvoltage simulation method of the present invention;

[0051] Figure 6 The shunt reactor current waveform diagram when the vacuum circuit breaker described in the simulation experiment is disconnected; (a) is the shunt reactor current waveform diagram when the first phase is normally disconnected; (b) is the shunt reactor current waveform diagram when the first phase is continuously reignited;

[0052] Figure 7 The waveform diagram of the first open phase when the re-ignition occurs continuously in the simulation experiment; (a) is the A current waveform diagram; (b) is the B phase current waveform diagram; (c) is the C phase current waveform diagram;

[0053] Figure 8 The bus side overvoltage waveform diagram described in the simulation experiment; (a) is the bus side relative overvoltage waveform diagram; (b) is the bus side phase-to-phase overvoltage waveform diagram;

[0054] Fig. 9 The overvoltage waveforms of the shunt reactor side described in the simulation experiment; (a) is the overvoltage waveform of the shunt reactor side relative to ground; (b) is the overvoltage waveform of the shunt reactor side between phases; (c) is the overvoltage waveform of the shunt reactor turn-to-turn. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not used to limit the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions.

[0056] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or devices.

[0057] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0058] like Figure 2-Figure 5 As shown, a method for simulating overvoltage of a shunt reactor comprises the following steps:

[0059] S1. Considering the circuit breaker breaking process, the dielectric dynamic insulation strength recovery process, and the arc restrike judgment mechanism, a vacuum circuit breaker simulation model is constructed based on the ATP-EMTP software platform;

[0060] The vacuum circuit breaker simulation model described in step S1 includes a MODEL module and a SW-TACS switch; wherein the MODEL module is used to judge the behavior of the simulated circuit breaker under different working conditions through input quantities, and the SW-TACS switch is used to simulate the operation of the actual circuit breaker based on the switch control signal output by the MODEL module;

[0061] The input quantities of the MODEL module are the voltage across the vacuum circuit breaker, the current flowing through the vacuum circuit breaker, the current zero-crossing judgment, and the rate of change of the current with respect to time. The data output quantities of the MODEL module include the break recovery voltage and the break dielectric insulation strength. The MODEL module also outputs a switch control signal for controlling the closing and opening of the SW-TACS switch.

[0062] In step S1, the ATP-EMTP software platform is used to establish the simulation of zero-crossing breaking and arc restrike of the vacuum circuit breaker, and the control and switch programs are written in Fortran language to obtain the simulation model of the vacuum circuit breaker and simulate the working process of the vacuum circuit breaker.

[0063] S2. Using the ATP-EMTP software platform, and based on the vacuum circuit breaker simulation model constructed in step S1 and combining system parameters, establish a shunt reactor simulation model;

[0064] The shunt reactor simulation model described in step S2 includes a 35kV bus, a running line connected to the 35kV bus, and the vacuum circuit breaker simulation model, shunt reactor and lightning arrester described in step S1 connected to the 35kV bus in sequence, wherein both ends of the vacuum circuit breaker simulation model are grounded via distributed capacitors, and the vacuum circuit breaker is connected to the shunt reactor via a cable;

[0065] The system parameters are as follows: Shunt reactor: rated voltage 35kV, rated capacity 3.34Mvar, inductance per phase 380mH, winding resistance 1.2Ω;

[0066] Cable: single-core cable, length 100m, inductance per unit length 0.38μH / m, single-phase capacitance to ground 22nF;

[0067] Lightning arrester: zinc oxide lightning arrester, voltage level 35kV, rated voltage 51kV, DC 1mA reference voltage 75.3kV.

[0068] S3. Use the vacuum circuit breaker simulation model constructed in step S1 to simulate the behavior of the vacuum circuit breaker, perform first-phase continuous re-ignition, equivalent cutoff simulation and continuous re-ignition to equivalent cutoff simulation on the shunt reactor simulation model described in step S2, and output the simulation results.

[0069] Step S3 specifically includes the following steps:

[0070] S31, using the MODEL module to issue a disconnection command;

[0071] S32, determine whether the current I flowing through the vacuum circuit breaker is less than the cut-off current I mar If yes, it indicates that the vacuum circuit breaker starts to break, and execute step S33; otherwise, execute waiting. mar <5A; that is, because at the power frequency moment, when the current is about to pass through the first zero crossing point, the current will fluctuate, and the process of being cut off after the oscillation is relatively complicated. It is difficult to simulate its specific changes in the simulation, and the impact on the accuracy of the simulation is small. Therefore, the cut-off is directly defined in the simulation as jumping to zero when it is less than the set cut-off value.

[0072] S33, the vacuum circuit breaker enters the breaking state, the arc gap of the vacuum circuit breaker is transformed into an insulating medium, a piecewise fitting function between the vacuum circuit breaker breaking time and the dynamic insulation strength is constructed, and then the zero-crossing time is input into the piecewise fitting function to obtain the dynamic insulation strength u d ;

[0073] The piecewise fitting function expression in step S33 is as follows:

[0074]

[0075] Where, t d Indicates the breaking time of the vacuum circuit breaker in ms, t d The range is 0-3.33ms.

[0076] S34. After the circuit breaker is turned into the open state, the insulation medium recovery strength between the vacuum circuit breaker breaks increases with the increase of the break distance. At the same time, the circuit breaker break recovery voltage also increases. Therefore, the dynamic insulation strength u d Is it less than the break recovery voltage u f If yes, the vacuum circuit breaker is closed to simulate the continuous re-ignition and equivalent cutoff of the first-open phase, otherwise the vacuum circuit breaker enters the breaking state described in step S33;

[0077] S35, determine whether the breaking condition is met, if so, enter the breaking state described in step S33, and simulate continuous re-ignition to equivalent cutoff in this process, if not, maintain the closed state.

[0078] The breaking conditions in step S35 include simultaneously satisfying the current zero-crossing condition, the high-frequency current zero-crossing arc-extinguishing capability condition and the minimum arcing time condition;

[0079] The current zero-crossing condition is as follows: Collect the current signal I flowing through the vacuum circuit breaker at time t t , and collect the current signal I output after a delay of Δt t-Δt (The current signal is output after being delayed by Δt through a delay device). If the current I t ×I t-Δt <0, the current is judged to have passed through zero point; that is, the change of the positive and negative signs of the current value is used to judge whether the current has passed through zero point.

[0080] The conditions for the high-frequency current zero-crossing arc extinguishing capability are as follows: Since the vacuum circuit breaker's ability to extinguish arcs when the high-frequency current crosses zero is related to the rate of change of the current over time near the zero-crossing point, if the rate of change of the current over time is Where λ represents the set threshold, and the value range of λ is 50A / us-300A / us;

[0081] The minimum arcing time condition is as follows: T>T s , where T s is the minimum arcing time, and T is the arcing time.

[0082] A shunt reactor overvoltage simulation system is used to execute a shunt reactor overvoltage simulation method, which includes a parameter setting module, a simulation model building module, a data acquisition module and a simulation result output display module; wherein the parameter setting module is used to set model parameters; the simulation model building module is used to establish a shunt reactor simulation model according to the set model parameters; the data acquisition module is used to collect simulation results of the shunt reactor simulation model; and the simulation result output display module is used to output and display the simulation results.

[0083] A computer device comprises a memory, a processor and a computer program stored in the memory and running on the processor. When the processor executes the computer program, a method for simulating overvoltage of a shunt reactor is implemented.

[0084] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements a method for simulating overvoltage of a shunt reactor.

[0085] Simulation experiment

[0086] Parameter configuration: λ=300A / us, I mar =3A, t d =1.5ms; Reactor: rated voltage 35kV, rated capacity 3.34Mvar, inductance per phase 380mH, winding resistance 1.2 ohms. And the distributed capacitance is set to 500pF according to the dry air-core reactor capacitance value. Cable: Single-core cable model is YJV22-35kV 1×300, length is 100m, unit length inductance is about 0.38μH / m, single-phase capacitance of the cable to ground is 22nF, equivalent to 183pF / m. Arrester model is Y10W1-51 / 134, and the volt-ampere characteristics are shown in the following table.

[0087] Table 1 volt-ampere characteristic parameters of lightning arrester

[0088] I(A) 0.001 250 500 1000 2500 5000 10000 20000 U(kV) 75.3 102.4 105.2 110 117.2 124.1 133.2 143.8

[0089] Based on the above configuration and the method of the present invention, the following simulation is performed:

[0090] The simulated waveform of the current flowing through the shunt reactor when the shunt reactor is normally disconnected and the first phase is continuously reignited is as follows: Figure 6 As shown. Figure 6 As shown in Figure (a), after the shunt reactor is normally disconnected, a low-damped free oscillation current of about 10A appears in the shunt reactor. Figure 6 As can be seen from Figure (b), each time the vacuum circuit breaker reignites, the energy of the shunt reactor is replenished, and the current increases by several amperes. After the high-frequency transient current extinguishes the arc, the current of the shunt reactor is able to charge the distributed capacitance to the ground on the shunt side, and the recovery voltage rises more rapidly. The break is broken down again, entering a "reignition-breakdown" cycle, and the current of the shunt reactor is continuously raised.

[0091] Equivalent cutoff simulation

[0092] like Figure 7 As shown in the figure, when the first phase reignites continuously, equivalent current cutoff will occur in the next two phases, and when equivalent current cutoff occurs almost simultaneously in the next two phases, phase B and phase C, at about 12.5ms, their currents are basically equal in magnitude and opposite in direction, so the polarity of the equivalent current cutoff overvoltage induced is also opposite.

[0093] In summary, during the interruption of the 35kV shunt reactor, when the equivalent current of the two phases of the latter phase is cut off, the current during the cut-off can be as high as 100A or more, which causes a strong equivalent current cut-off overvoltage. That is, the combined effect of the continuous re-ignition of the first phase and the equivalent current cut-off leads to the overvoltage during the interruption.

[0094] Simulation of continuous re-ignition to equivalent cutoff

[0095] When the first phase is continuously reignited and the two phases are equivalently cut off, strong phase-to-ground and phase-to-phase overvoltages will appear on the shunt side. Therefore, the phase-to-ground, phase-to-phase and turn-to-turn overvoltages on the shunt side are considered in the simulation. In addition, when the vacuum circuit breaker switches the shunt reactor, the three-phase-to-ground and phase-to-phase overvoltages on the bus side are also calculated.

[0096] Table 2 Calculation results of overvoltage for breaking 35kV shunt reactor

[0097]

[0098] like Figure 8 As shown, when the busbar and the arrester operate normally, the overvoltage on the busbar side relative to the ground is about 93.8 kV (2.83 pu), and the overvoltage between phases is about 147.5 kV (4.46 pu).

[0099] like Fig. 9 As shown, the relative overvoltage on the shunt reactor side is 97.3 kV (2.94 pu), the phase-to-phase overvoltage on the shunt reactor side is around 170.5 kV (5.15 pu), and the turn-to-turn overvoltage of the shunt reactor is 110.7 kV (3.34 pu).

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for simulating overvoltage of a shunt reactor, characterized in that: The following steps are involved: S1. Considering the circuit breaker breaking process, the dielectric dynamic insulation strength recovery process, and the arc restrike judgment mechanism, a vacuum circuit breaker simulation model is constructed based on the ATP-EMTP software platform; S2. Using the ATP-EMTP software platform, and based on the vacuum circuit breaker simulation model constructed in step S1 and combining system parameters, establish a shunt reactor simulation model; S3. Use the vacuum circuit breaker simulation model constructed in step S1 to simulate the behavior of the vacuum circuit breaker, perform first-phase continuous re-ignition, equivalent cutoff simulation and continuous re-ignition to equivalent cutoff simulation on the shunt reactor simulation model described in step S2, and output the simulation results.

2. The method for simulating overvoltage of a shunt reactor according to claim 1, characterized in that: The vacuum circuit breaker simulation model described in step S1 includes a MODEL module and a SW-TACS switch; wherein the MODEL module is used to judge the behavior of the simulated circuit breaker under different working conditions through input quantities, and the SW-TACS switch is used to simulate the operation of the actual circuit breaker based on the switch control signal output by the MODEL module; The input quantities of the MODEL module are the voltage across the vacuum circuit breaker, the current flowing through the vacuum circuit breaker, the current zero-crossing judgment, and the rate of change of the current with respect to time. The data output quantities of the MODEL module include the break recovery voltage and the break dielectric insulation strength. The MODEL module also outputs a switch control signal for controlling the closing and opening of the SW-TACS switch.

3. A shunt reactor overvoltage simulation method according to claim 2, characterized in that: In step S1, the ATP-EMTP software platform is used to establish the simulation of zero-crossing breaking and arc restrike of the vacuum circuit breaker, and the control and switch programs are written in Fortran language to obtain the simulation model of the vacuum circuit breaker and simulate the working process of the vacuum circuit breaker.

4. A shunt reactor overvoltage simulation method according to claim 3, characterized in that: The shunt reactor simulation model described in step S2 includes a 35kV bus, a running line connected to the 35kV bus, and the vacuum circuit breaker simulation model, shunt reactor and lightning arrester described in step S1 connected to the 35kV bus in sequence, wherein both ends of the vacuum circuit breaker simulation model are grounded via distributed capacitors, and the vacuum circuit breaker is connected to the shunt reactor via a cable; The system parameters are as follows: Shunt reactor: rated voltage 35kV, rated capacity 3.34Mvar, inductance per phase 380mH, winding resistance 1.2Ω; Cable: single-core cable, length 100m, inductance per unit length 0.38μH / m, single-phase capacitance to ground 22nF; Lightning arrester: zinc oxide lightning arrester, voltage level 35kV, rated voltage 51kV, DC 1mA reference voltage 75.3kV.

5. A method for simulating overvoltage of a shunt reactor according to claim 4, characterized in that: Step S3 specifically includes the following steps: S31, using the MODEL module to issue a disconnection command; S32, determine whether the current I flowing through the vacuum circuit breaker is less than the cut-off current I mar If yes, it indicates that the vacuum circuit breaker starts to break, and the process goes to step S33; otherwise, the process goes to wait; S33, the vacuum circuit breaker enters the breaking state, the arc gap of the vacuum circuit breaker is transformed into an insulating medium, a piecewise fitting function between the vacuum circuit breaker breaking time and the dynamic insulation strength is constructed, and then the zero-crossing time is input into the piecewise fitting function to obtain the dynamic insulation strength u d ; S34. Determine the dynamic insulation strength u d Is it less than the break recovery voltage u f If yes, the vacuum circuit breaker is closed to simulate the continuous re-ignition and equivalent cutoff of the first-open phase, otherwise the vacuum circuit breaker enters the breaking state described in step S33; S35, determine whether the breaking condition is met, if so, enter the breaking state described in step S33, and simulate continuous re-ignition to equivalent cutoff in this process, if not, maintain the closed state.

6. A method for simulating overvoltage of a shunt reactor according to claim 5, characterized in that: The piecewise fitting function expression in step S33 is as follows: Where, t d Indicates the breaking time of the vacuum circuit breaker in ms.

7. A shunt reactor overvoltage simulation method according to claim 6, characterized in that: The breaking conditions in step S35 include simultaneously satisfying the current zero-crossing condition, the high-frequency current zero-crossing arc-extinguishing capability condition and the minimum arcing time condition; The current zero-crossing condition is as follows: Collect the current signal I flowing through the vacuum circuit breaker at time t t , and collect the current signal I output after a delay of Δt t-Δt , if the current I at time t t ×I t-Δt <0, the current is judged to be zero-crossing; The conditions for the high-frequency current zero-crossing arc extinguishing capability are as follows: If the rate of change of the current flowing through the Where λ represents the set threshold; The minimum arcing time condition is as follows: T>T s , where T s is the minimum arcing time, and T is the arcing time.

8. A shunt reactor overvoltage simulation system, characterized in that: A method for simulating overvoltage of a shunt reactor according to any one of claims 1 to 7, comprising a parameter setting module, a simulation model building module, a data acquisition module and a simulation result output display module; Among them, the parameter setting module is used to set the model parameters; The simulation model building module is used to build a shunt reactor simulation model according to the set model parameters; The data acquisition module is used to collect simulation results of the shunt reactor simulation model; The simulation result output display module is used to output and display the simulation results.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, it implements the method for simulating overvoltage of a shunt reactor as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for simulating overvoltage of a shunt reactor as described in any one of claims 1 to 7 is implemented.

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