A shunt reactor overvoltage simulation method, system, device and medium

Abstract

The application discloses a kind of shunt reactor overvoltage simulation simulation method, system, equipment and medium, belong to shunt reactor overvoltage simulation field, comprising the following steps: S1, considering the breaking process of circuit breaker, dielectric dynamic insulation strength recovery process, arc reignition judgment mechanism, based on ATP-EMTP software platform, constructs vacuum circuit breaker simulation model;S2, using ATP-EMTP software platform, and based on vacuum circuit breaker simulation model is combined with system parameters, establishes shunt reactor simulation model;S3, the behavior of vacuum circuit breaker is simulated using vacuum circuit breaker simulation model, respectively to the first open phase continuous reignition of shunt reactor simulation model, equivalent current interruption simulation and continuous reignition to equivalent current interruption simulation, and output simulation result.The shunt reactor overvoltage simulation simulation method, system, equipment and medium described above, by simulating the breaking process of vacuum circuit breaker, reveals the main cause of overvoltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shunt reactor overvoltage simulation, and particularly relates to a shunt reactor overvoltage simulation method, system, device and medium. BACKGROUND

[0002] The shunt reactor is mainly used for compensating the capacitive reactive power of a line and stabilizing system voltage in a power system. Since the load of the power system changes over time, the shunt reactor also needs to be frequently switched on and off in order to compensate for the reactive power. However, overvoltage may occur during the switching on and off of the shunt reactor, which poses a threat to the safe operation of the power system.

[0003] In a distribution network, a vacuum circuit breaker is generally selected for switching on and off the shunt reactor. The vacuum circuit breaker has the advantages of high electrical recovery strength, good arc extinguishing capability and good frequent operation characteristics, etc. However, the vacuum circuit breaker also has a current chopping effect, which easily causes overvoltage problems, seriously threatens the insulation safety of equipment and affects the safe and stable operation of the power system.

[0004] In recent years, when a vacuum circuit breaker is used to cut off a 35kV shunt reactor, the reactor switch cabinet is burned or internally broken down due to operation overvoltage multiple times. Therefore, the prior art has made the following research on the overvoltage line type:

[0005] Past researches believe that the overvoltage phenomenon is caused by current chopping during breaking. When the current chopping value is near 3A, the current chopping phenomenon of the vacuum circuit breaker has little effect on the overvoltage amplitude. However, as the current chopping value increases, the chopping overvoltage multiple increases significantly. When the system is an empty bus without outgoing lines, the bus side has a small capacitance to ground, and the rekindling caused by breaking will cause a large oscillation on the bus side. At the same time, due to the instability of the vacuum arc, the current chopping phenomenon is difficult to avoid during breaking of all small current loads. Moreover, the current chopping value is less than 5A, and has little effect on the recovery voltage of the two ends of the circuit breaker, so it is not the root cause of the subsequent serious overvoltage.

[0006] As can be seen from the above, rekindling is unavoidable, and the rekindling overvoltage caused by the rekindling of a certain phase current is not strong. Multiple repeated rekindling will cause continuous energy supplement and induce voltage level rise effect. However, at this time, the relative ground and inter-phase overvoltage of the other two phases is not large, which cannot explain some inter-phase overvoltage accidents.

[0007] The current explanation of the cause of the overvoltage of the 35kV shunt reactor is that the first phase repeatedly reignites, and then the equivalent chopped current overvoltage of the last two phases occurs (the phase currents are 120° apart, so at a certain moment after the breaker is opened, there must be a phase current that first crosses the zero point and extinguishes the arc, and this phase is called the first opening phase, and the two phases that follow are called the last opening phase), and the reignition of the first opening phase is due to the fact that the growth rate of the insulation strength at both ends of the vacuum breaker is much smaller than the rising rate of the recovery voltage at the break.

[0008] For example, as shown in Figure 1 the first opening phase B phase current crosses zero at 575ms-576ms and then continuously reignites for about 3.5ms, and the voltage level rising effect caused by the reignition of the first opening phase B phase is very significant, and with the repeated occurrence of the reignition, the oscillation becomes more and more intense. At this time, although the A and C phases have not crossed zero, the high-frequency transient current is coupled to the currents of the last two phases A and C through the interphase coupling, so high-frequency oscillation of the current also occurs, and when the high-frequency crosses the zero point, the breaker extinguishes the arc in advance, i.e. the last two phases of the power frequency current have not crossed zero, but are forced to be opened, at this time, the magnetic field energy of the chopped current value will be converted into the electric field energy of the shunt side-to-ground capacitance, so the overvoltage is very serious when the chopped current value is in an extreme case.

[0009] In summary, the mechanism of the equivalent chopped current overvoltage is that when the first opening phase reignites, the transient current is superimposed on the currents of the last two phases that have not crossed zero due to the coupling among the three phases. After the reignition occurs, the strength of the break voltage is enhanced, and the transient oscillation is continuously enhanced, causing the last two phases of the current to appear high-frequency zero points, and the breaker can open the high-frequency current after continuous processing, so the high-frequency current is cut off, and the overvoltage produced by the high-frequency current is similar to the effect of the chopped current overvoltage of the breaker. However, this chopped current is a high-frequency current over-zero arc extinguishing, and does not occur at the power frequency, and because the break is open, the current only oscillates between the shunt side capacitance and the reactor inductance, and exchanges energy, so the same effect as the chopped current overvoltage occurs, which is called the equivalent chopped current overvoltage.

[0010] However, because the breaker can continuously break through hundreds of times within a few milliseconds, it is impossible to simulate the continuous breakdown process of the load by using a simple switch model. SUMMARY

[0011] The purpose of the present application is to provide a shunt reactor overvoltage simulation method, system, device and medium, which solves the above technical problems.

[0012] To achieve the above purpose, the present application provides a shunt reactor overvoltage simulation method, which comprises the following steps:

[0013] S1, considering the breaking process of the circuit breaker, the recovery process of the dielectric dynamic insulation strength, and the arc reignition judgment mechanism, a simulation model of the vacuum circuit breaker is built based on an ATP-EMTP software platform;

[0014] S2, a simulation model of the shunt reactor is built by using the ATP-EMTP software platform, based on the simulation model of the vacuum circuit breaker built in step S1, and combined with system parameters;

[0015] S3, the behavior of the vacuum circuit breaker is simulated by using the simulation model of the vacuum circuit breaker built in step S1, and the simulation model of the shunt reactor described in step S2 is subjected to continuous reignition of the first opening phase, equivalent current interruption simulation, and continuous reignition to equivalent current interruption simulation, respectively, and the simulation results are output.

[0016] Preferably, the simulation model of the vacuum circuit breaker described in step S1 comprises 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 by 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 respectively 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 recovery voltage of the contact and the dielectric insulation strength of the contact, and 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 simulation of the zero-crossing breaking and arc reignition of the vacuum circuit breaker is established by using the ATP-EMTP software platform, and the control and switch programs are written in Fortran language to obtain the simulation model of the vacuum circuit breaker, which simulates the working process of the vacuum circuit breaker.

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

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

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

[0022] Surge arrester: Zinc oxide surge arrester, voltage level 35kV, rated voltage 51kV, DC 1mA reference voltage 75.3kV.

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

[0024] S31. Use the MODEL module to issue an on / off command;

[0025] S32. Determine whether the current I flowing through the vacuum circuit breaker is less than the cutoff current I. mar If yes, it indicates that the vacuum circuit breaker has started to open, and step S33 is executed; otherwise, wait is executed.

[0026] S33. When the vacuum circuit breaker enters the breaking state, the arc gap of the vacuum circuit breaker transforms into an insulating medium. A piecewise fitting function is constructed between the breaking time of the vacuum circuit breaker and the dynamic insulation strength. The zero-crossing time is then 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 so, the vacuum circuit breaker closes to simulate continuous reignition of the first open phase and equivalent current cut-off; otherwise, the vacuum circuit breaker enters the interruption state described in step S33.

[0028] S35. Determine whether the interruption condition is met. If yes, proceed to the interruption state described in step S33, and simulate continuous reignition to equivalent throttling during this process. If not, maintain the closed state.

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

[0030]

[0031] In the formula, t d This indicates the breaking time of the vacuum circuit breaker, in milliseconds (ms).

[0032] Preferably, the interruption conditions described 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.

[0033] The current zero-crossing condition is as follows: The current signal I flowing through the vacuum circuit breaker at time t is collected. t And acquire the current signal I output after a delay of Δt. t-Δt If the current I at time t t ×I t-Δt If the value is less than 0, then the current is determined to be at zero-crossing point;

[0034] The conditions for high-frequency current zero-crossing arc extinction capability are as follows: if the rate of change of the flowing current with respect to time... wherein λ represents a set threshold value;

[0035] The minimum arc burning time condition is as follows: T > T s wherein T s is the minimum arc burning time, and T is the arc burning time.

[0036] A shunt reactor overvoltage simulation system for performing a shunt reactor overvoltage simulation method, comprising a parameter setting module, a simulation model establishing module, a data acquisition module and a simulation result output display module.

[0037] The parameter setting module is configured to set model parameters.

[0038] The simulation model establishing module is configured to establish a shunt reactor simulation model according to the set model parameters.

[0039] The data acquisition module is configured to acquire simulation results of the shunt reactor simulation model.

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

[0041] A computer device comprising a memory, a processor and a computer program stored on the memory and running on the processor, wherein the processor implements a shunt reactor overvoltage simulation method when executing the computer program.

[0042] A computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement a shunt reactor overvoltage simulation method.

[0043] Therefore, the shunt reactor overvoltage simulation method, system, device and medium have the following beneficial effects:

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

[0045] The technical solutions of the present application will be further described in detail below with reference to the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is an equivalent current interruption waveform diagram of a certain power supply company;

[0047] Figure 2 is a flowchart of the shunt reactor overvoltage simulation method of the present application;

[0048] Figure 3A parallel reactor simulation model configuration diagram for a parallel reactor overvoltage simulation and simulation method of the present application;

[0049] Figure 4 A parallel reactor simulation model schematic diagram for a parallel reactor overvoltage simulation and simulation method of the present application;

[0050] Figure 5 A vacuum circuit breaker simulation model schematic diagram for a parallel reactor overvoltage simulation and simulation method of the present application;

[0051] Figure 6 A parallel reactor current waveform diagram when the vacuum circuit breaker is opened for simulation experiments; wherein (a) is a parallel reactor current waveform diagram when the first open phase is normally opened; (b) is a parallel reactor current waveform diagram when the first open phase continuously reignites;

[0052] Figure 7 A waveform diagram when the first open phase continuously reignites for simulation experiments; wherein (a) is an A current waveform diagram; (b) is a B phase current waveform diagram; (c) is a C phase current waveform diagram;

[0053] Figure 8 A bus side overvoltage waveform diagram for simulation experiments; wherein (a) is a bus side relative ground overvoltage waveform diagram; (b) is a bus side interphase overvoltage waveform diagram;

[0054] Figure 9 A parallel reactor side overvoltage waveform diagram for simulation experiments; wherein (a) is a parallel reactor side relative ground overvoltage waveform diagram; (b) is a parallel reactor side interphase overvoltage waveform diagram; (c) is a parallel reactor interturn overvoltage waveform diagram. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application are further described in detail below in combination with the drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present application and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout.

[0056] It is to be understood that the terms "including", "comprising", "having" and their conjugates mean "including but not limited to", e.g. a process, method, object, or apparatus that includes a list of steps or elements is not necessarily limited to those specifically listed and can include other steps or elements not expressly listed or inherent to such process, method, object, or apparatus.

[0057] The embodiments of the present application will be described in detail below with reference to the drawings.

[0058] As shown in the figure, a shunt reactor overvoltage simulation method comprises the following steps: Figures 2-5

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

[0060] The vacuum circuit breaker simulation model of step S1 comprises 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 conditions through input variables, 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 variables 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, and the data output variables of the MODEL module include the recovery voltage of the contact and the dielectric insulation strength of the contact medium, and 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 a simulation of the vacuum circuit breaker zero-crossing breaking and arc reignition, and a Fortran language is used to write a control and switch program to obtain a vacuum circuit breaker simulation model for simulating the working process of the vacuum circuit breaker.

[0063] S2, using the ATP-EMTP software platform and the vacuum circuit breaker simulation model constructed based on step S1 in combination with system parameters, a shunt reactor simulation model is established;

[0064] The shunt reactor simulation model of step S2 comprises a 35kV bus, an operating line connected to the 35kV bus, and in turn, the vacuum circuit breaker simulation model of step S1, the shunt reactor, and the surge arrester connected to the 35kV bus, wherein both ends of the vacuum circuit breaker simulation model are grounded through a distributed capacitor, and the vacuum circuit breaker is connected to the shunt reactor through a cable.

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

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

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

[0068] S3, simulating the behavior of the vacuum circuit breaker by using the vacuum circuit breaker simulation model constructed in step S1, performing first open-phase continuous reignition, equivalent current interruption simulation and continuous reignition to equivalent current interruption simulation on the shunt reactor simulation model described in step S2 respectively, and outputting simulation results.

[0069] Step S3 specifically includes the following steps:

[0070] S31, issuing an open command by using the MODEL module;

[0071] S32, judging whether the current I flowing through the vacuum circuit breaker is less than the cutoff current I mar , if yes, indicating that the vacuum circuit breaker starts to open, executing step S33, otherwise, executing waiting, I mar < 5 A; that is, because at the time of power frequency, the current will fluctuate when it is about to pass through the first zero point, the process of oscillation and current interruption is relatively complex, it is difficult to simulate the specific changes in the simulation, and the influence on the accuracy of the simulation is small, therefore, the current interruption is directly defined as less than the set current interruption value in the simulation to jump to zero.

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

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

[0074]

[0075] In the formula, t d represents the breaking time of the vacuum circuit breaker, and the unit is ms, t d ranges from 0 to 3.33 ms.

[0076] S34, since the vacuum circuit breaker becomes open state, the recovery strength of the insulating medium between the vacuum circuit breaker breaks increases with the increase of the break opening distance, at the same time, the recovery voltage of the circuit breaker break is also enhanced, so the dynamic insulation strength u d is less than the break recovery voltage u f , if yes, the vacuum circuit breaker is closed to simulate the continuous reignition and equivalent current interruption of the first open phase, otherwise the vacuum circuit breaker enters the open state described in step S33;

[0077] S35, determine whether the opening condition is met, if yes, enter the open state described in step S33, and simulate the continuous reignition to the equivalent current interruption in the process, if not, keep the closed state.

[0078] The opening condition described in step S35 includes simultaneously meeting the current zero crossing condition, the high frequency current zero crossing arc extinguishing ability condition and the minimum arc time condition;

[0079] The current zero crossing condition is as follows: the current signal I t flowing through the vacuum circuit breaker at time t is collected t-Δt , and the current signal I t output after a delay Δt (the current signal is output after a delay Δt through a time delay) is collected, if the current I t-Δt at time t is zero, it is determined that the current zero point is crossed; that is, the change of the positive and negative signs of the current value is used to determine whether the current zero point is crossed.

[0080] The high frequency current zero crossing arc extinguishing ability condition is as follows: since the ability of the vacuum circuit breaker to extinguish the arc of the high frequency current zero crossing is related to the rate of change of the current with respect to time near the zero crossing point, if the rate of change of the current with respect to time where λ represents a set threshold, and λ takes a value in the range of 50A / us-300A / us;

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

[0082] A shunt reactor overvoltage simulation system for performing a shunt reactor overvoltage simulation method, which comprises a parameter setting module, a simulation model establishing module, a data acquisition module and a simulation result output display module; wherein the parameter setting module is used to set the model parameters; the simulation model establishing module is used to establish a shunt reactor simulation model according to the set model parameters; the data acquisition module is used to acquire the 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 on the memory and running on the processor, and the processor implements a parallel reactor overvoltage simulation method when executing the computer program.

[0084] A computer readable storage medium has a computer program stored thereon, and the computer program implements a parallel reactor overvoltage simulation method when executed by a processor.

[0085] Simulation experiment

[0086] Parameter configuration: λ = 300 A / us, I mar = 3 A, t d = 1.5 ms; Reactor: rated voltage 35 kV, rated capacity 3.34 Mvar, inductance per phase 380 mH, winding resistance 1.2 ohms. And the distributed capacitance is set to 500 pF according to the dry-type air-core reactor capacitance value. Cable: single-core cable model YJV22-35 kV 1x300, length 100 m, inductance per unit length about 0.38 μH / m, single-phase-to-ground capacitance of the cable is 22 nF, equivalent to 183 pF / m. Arrester model Y10W1-51 / 134, the volt-ampere characteristic is shown in the following table.

[0087] Table 1 volt-ampere characteristic parameters of the 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, the method described in the application is simulated as follows:

[0090] The current simulation waveform of the parallel reactor when the parallel reactor is normally opened and the first open phase continuously reignites is shown in Figure 6 As shown in Figure 6 (a), after the normal opening of the parallel reactor, a low-damping free oscillation current of about 10 A appears in the parallel reactor; as shown in Figure 6 (b), each time the vacuum circuit breaker reignites, the energy of the parallel reactor is replenished, the current increases by several amperes, after the high-frequency transient current arcs, the ability of the current of the parallel reactor to charge the distributed capacitance of the ground on the parallel reactor side is strengthened, and the recovery voltage rises more quickly, the gap is broken down again, and enters the "reignition-breakdown" cycle, and the current of the parallel reactor is continuously raised.

[0091] Equivalent current interruption simulation

[0092] As shown in Figure 7 , when the first open phase continuously reignites, it will cause the occurrence of equivalent current interruption of the latter two phases, and when the latter two phases B and C almost simultaneously occur at about 12.5 ms, the current size is basically equal and the direction is opposite, so the polarity of the equivalent current interruption overvoltage caused is also opposite.

[0093] In summary, during the interruption process of a 35kV shunt reactor, when the equivalent current cutoff occurs in the two phases of the later-opening phase, the current during the cutoff can reach as high as 100A or more, thus triggering a strong equivalent current-cutoff overvoltage. That is, the combined effect of the continuous reignition of the first-opening phase and the equivalent current-cutoff leads to the overvoltage during reactor interruption.

[0094] Continuous reignition to equivalent cutoff simulation

[0095] When the first phase reignites continuously and the two phases are equivalently cut off, strong phase-to-ground and phase-to-phase overvoltages will occur on the shunt side. Therefore, 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 when interrupting a 35kV parallel reactor.

[0097]

[0098] like Figure 8 As shown, under normal operation of the busbar and surge arrester, the phase-to-ground overvoltage on the busbar side is about 93.8kV (2.83pu), and the phase-to-phase overvoltage is about 147.5kV (4.46pu).

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

[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. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for simulating overvoltage of a shunt reactor, characterized in that: Includes the following steps: S1. Considering the circuit breaker breaking process, the dynamic insulation strength recovery process of the medium, and the arc reignition judgment mechanism, a simulation model of a vacuum circuit breaker 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, combined with the system parameters, establish a parallel reactor simulation model. S3. Using the vacuum circuit breaker simulation model constructed in step S1, simulate the behavior of the vacuum circuit breaker. Perform simulations of continuous reignition of the first open phase, equivalent current throttling, and continuous reignition to equivalent current throttling on the parallel reactor simulation model described in step S2, and output the simulation results. Step S3 specifically includes the following steps: S31. Use the MODEL module to issue an on / off command; S32. Determine whether the current I flowing through the vacuum circuit breaker is less than the cutoff current I. mar If yes, it indicates that the vacuum circuit breaker has started to open, and step S33 is executed; otherwise, wait is executed. S33. When the vacuum circuit breaker enters the breaking state, the arc gap of the vacuum circuit breaker transforms into an insulating medium. A piecewise fitting function is constructed between the breaking time of the vacuum circuit breaker and the dynamic insulation strength. The zero-crossing time is then 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 so, the vacuum circuit breaker closes to simulate continuous reignition of the first open phase and equivalent current cut-off; otherwise, the vacuum circuit breaker enters the interruption state described in step S33. S35. Determine whether the interruption condition is met. If yes, proceed to the interruption state described in step S33, and simulate continuous reignition to equivalent throttling during this process. If not, maintain the closed state.

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 determine the behavior of the simulated circuit breaker under different operating 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 inputs to 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 current with respect to time. The data outputs of the MODEL module include the break recovery voltage and the dielectric insulation strength of the break. The MODEL module also outputs switch control signals to control the closing and opening of the SW-TACS switch.

3. The method for simulating overvoltage of a parallel reactor according to claim 2, characterized in that: In step S1, the ATP-EMTP software platform is used to establish a simulation of the vacuum circuit breaker's zero-crossing interruption and arc reignition. The control and switching programs are written in Fortran language to obtain a simulation model of the vacuum circuit breaker and to simulate the working process of the vacuum circuit breaker.

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

5. The method for simulating overvoltage of a shunt reactor according to claim 1, characterized in that: The expression for the piecewise fitting function described in step S33 is as follows: In the formula, t d This indicates the breaking time of the vacuum circuit breaker, in milliseconds (ms).

6. The method for simulating overvoltage of a shunt reactor according to claim 5, characterized in that: The interruption conditions described 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: The current signal I flowing through the vacuum circuit breaker at time t is collected. t And acquire the current signal I output after a delay of Δt. t-Δt If the current I at time t t ×I t-Δt If the value is less than 0, then the current is determined to be at zero-crossing point; The conditions for high-frequency current zero-crossing arc extinction capability are as follows: if the rate of change of the flowing current with respect to time... Where λ represents the set threshold; The minimum arcing time condition is as follows: T > T s , among which, T s Let T be the minimum arcing time, and T be the arcing time.

7. A simulation system for overvoltage of a shunt reactor, characterized in that: A method for simulating overvoltage of a shunt reactor as described in any one of claims 1-6, comprising a parameter setting module, a simulation model establishment module, a data acquisition module, and a simulation result output and display module; The parameter setting module is used to set model parameters; The simulation model building module is used to build a simulation model of the shunt reactor based on the set model parameters; The data acquisition module is used to collect the simulation results of the parallel reactor simulation model; The simulation result output and display module is used to output and display the simulation results.

8. 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 a computer program, it implements the overvoltage simulation method for a parallel reactor as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the overvoltage simulation method for a parallel reactor as described in any one of claims 1-6.

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