Nonlinear circuit simulation method considering arc time-varying inductance and capacitance effect

Abstract

The invention discloses a nonlinear circuit simulation method considering arc time-varying inductance and capacitance effects, and relates to the field of circuit simulation. Comprising the steps of establishing a dynamic arc comprehensive equivalent model, innovatively introducing time-varying arc inductance and time-varying gap capacitance on the basis of a traditional time-varying arc resistance model, comprehensively representing dynamic physical characteristics of an arc, and dynamically coupling parameters of the time-varying inductance and the time-varying capacitance with mechanical motion characteristics of a disconnecting switch contact; controlling the reignition and extinguishing process of the arc by adopting a mixed criterion: taking a gas dielectric theory as an arc ignition criterion, and taking an energy balance theory as an arc extinguishing criterion; based on general electromagnetic simulation software, dynamic simulation of multiple breakdown processes is realized through a circuit, and time domain waveform and spectral characteristics of the VFTO are acquired and analyzed, so that more accurate prediction and analysis of the VFTO are realized, and the problem that an existing arc model is insufficient in very fast transient overvoltage simulation precision in GIS isolation switch operation is solved.

Description

Technical Field

[0001] This invention relates to the field of simulation technology, and in particular to a nonlinear circuit simulation method that takes into account the time-varying inductance and capacitance effects of electric arcs. Background Technology

[0002] In gas-insulated metal-enclosed switchgear (GIS), very fast transient overvoltages (VFTOs) are generated during the operation of disconnecting switches. This is an electromagnetic transient phenomenon caused by repeated breakdowns and arc extinctions between contacts. The cause lies in the relatively slow contact movement during the opening and closing of the disconnecting switch, leading to multiple breakdowns of the gap. Each breakdown generates a nanosecond-level extremely steep wavefront voltage pulse, which undergoes complex reflections and refractions through the GIS's piping structure, forming an overvoltage oscillation containing extremely high-frequency components. The hazards of VFTOs are mainly manifested in two aspects: first, their extremely steep wavefront and abundant high-frequency components can cause extremely uneven voltage distribution between turns, posing a serious threat to the insulation of primary equipment, especially longitudinal insulation; second, their powerful high-frequency electromagnetic field can couple to the secondary system through grounding wires or spatial radiation, potentially causing malfunctions or damage to protection and control equipment, posing a potential risk to the safe and stable operation of the GIS, and seriously threatening the reliable operation of the power system.

[0003] Currently, most simulation studies on VFTO are based on simplified arc models. These models are difficult to accurately describe the dynamic nonlinear process of multiple arc reignitions. In particular, they lack segmented and refined simulations of different physical characteristics throughout the entire arc cycle (pre-breakdown, stable arcing, and arc extinction). This results in discrepancies between the simulation results and measured data in terms of amplitude and spectral characteristics, making it impossible to provide sufficiently accurate references for engineering design.

[0004] Therefore, a nonlinear circuit simulation method that takes into account the time-varying inductance and capacitance effects of electric arc is provided to solve the above problems. Summary of the Invention

[0005] To address the aforementioned challenges, this invention provides a nonlinear circuit simulation method that considers the time-varying inductance and capacitance effects of the arc. By innovatively introducing time-varying arc inductance and time-varying gap capacitance on the basis of the traditional time-varying arc resistance model, it can more comprehensively characterize the dynamic physical characteristics of the arc, thereby achieving more accurate prediction and analysis of VFTO.

[0006] To achieve the above objectives, the present invention provides a nonlinear circuit simulation method that considers the time-varying inductance and capacitance effects of electric arcs, comprising the following steps: S1: Establish a dynamic arc comprehensive equivalent model, including time-varying arc resistance, time-varying arc inductance, and time-varying gap capacitance; S2: Dynamically couple the time-varying arc inductance and time-varying gap capacitance with the mechanical motion characteristics of the disconnecting switch contacts, wherein the mechanical motion characteristics include contact movement speed, movement time, and gap distance; S3: The reignition and extinction process of the electric arc is controlled by a hybrid criterion: the reignition of the electric arc is determined based on the gas dielectric theory, and the extinction of the electric arc is determined based on the energy balance theory. S4: Construct a simulation circuit in electromagnetic transient simulation software that includes the dynamic arc comprehensive equivalent model to simulate multiple breakdown phenomena during the operation of the disconnecting switch; S5: Acquire and analyze the time-domain waveform and spectral characteristics of ultra-fast transient overvoltages to achieve accurate prediction and analysis of VFTO.

[0007] Preferably, the time-varying arc resistance is modeled using a piecewise approach, specifically including: A hyperbolic resistance model is used in the pre-breakdown stage; A fixed-value resistor model is used in the stable arc-burning stage; The Mayr model is used during the arc extinction phase.

[0008] Preferably, the time-varying arc inductance is modeled using Martin's formula, expressed as: ; in, The arc path length varies with time and is equal to the gap distance between the moving and stationary contacts of the disconnecting switch, and is determined by the movement speed of the contacts and time.

[0009] Preferably, the arc channel length Specifically, it is expressed as follows: During the tripping operation: ; During the closing operation: ; in, The opening speed of the moving contact. The closing speed of the moving contact. This refers to the initial distance between the moving and stationary contacts of the isolating switch.

[0010] Preferably, the time-varying gap capacitance is expressed as: ; in, This represents the duration of the contact movement process.

[0011] Preferably, the method of determining whether an electric arc reignites based on the gas dielectric theory specifically includes: Real-time calculation of the recovery voltage of the disconnector contact gap Critical breakdown voltage at the current gap distance ; Compare the recovery voltage with the critical breakdown voltage; When the condition is met If the arc reignites, it is determined that the arc has reignited; otherwise, the arc remains extinguished. Among them, the critical breakdown voltage It is linearly proportional to the gap length of the disconnecting switch contacts.

[0012] Preferably, during the disconnection switch opening operation, the critical breakdown voltage is... Represented as: ; in, This refers to the breakdown voltage per unit length of the disconnector gap. For the operating speed of the disconnect switch, For time.

[0013] Preferably, during the closing operation of the disconnecting switch, the critical breakdown voltage is... Represented as: ; in, This represents the maximum opening distance of the switch contacts.

[0014] Preferably, the method of determining whether an electric arc has been extinguished based on the energy balance theory includes: Real-time monitoring of the current flowing through the arc channel ; Set current change rate threshold ; An electric arc is considered extinguished when all of the following conditions are met: (1) Current zero-crossing condition: ,in, This is the simulation time step; (2) Current change rate condition: .

[0015] Preferably, the electromagnetic transient simulation software is ATP-EMTP, and the dynamic control and logical judgment of arc resistance, inductance and capacitance are realized through the MODELS module.

[0016] Therefore, this invention employs a nonlinear circuit simulation method that considers the time-varying inductance and capacitance effects of the arc. By establishing a dynamic comprehensive equivalent model of the arc, it innovatively introduces time-varying arc inductance and time-varying gap capacitance on the basis of the traditional time-varying arc resistance model, to more comprehensively characterize the dynamic physical characteristics of the arc. A hybrid criterion is used to control the reignition and extinction processes of the arc: gas dielectric theory is used as the arc ignition criterion, and energy balance theory is used as the arc extinguishing criterion. Based on general electromagnetic simulation software, the circuit dynamically simulates multiple breakdown processes, acquiring and analyzing the time-domain waveform and spectral characteristics of VFTO, thereby achieving more accurate prediction and analysis of VFTO. This solves the problem of insufficient simulation accuracy of existing arc models (such as models that only consider resistance) for ultra-fast transient overvoltages in GIS disconnector operation, and provides relevant data references for the insulation coordination and electromagnetic compatibility design of GIS equipment.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of a nonlinear circuit simulation method that takes into account the time-varying inductance and capacitance effects of an electric arc according to the present invention. Figure 2 This is a schematic diagram of the GIS circuit model topology in an embodiment of the present invention; Figure 3 This is a schematic diagram of the GIS simulation circuit in an embodiment of the present invention; Figure 4 This is a schematic diagram of the arc control model in an embodiment of the present invention; Figure 5 This is a timing diagram of the arc reignition control signal in an embodiment of the present invention, wherein, Figure 5 (a) is a diagram of the input and output signals of the SR latch during a single arc ignition. Figure 5 (b) is a diagram of the Q1 signal during the entire closing operation; Figure 6 This is a timing diagram of operation commands and timing signals in an embodiment of the present invention, wherein, Figure 6 (a) is a diagram of the Q2 signal during the entire closing operation. Figure 6 (b) Q3 signal diagram of the entire closing operation process; Figure 7 This is a graph showing the change in arc resistance in an embodiment of the present invention, wherein, Figure 7 (a) is a graph showing the change in arc resistance during a single arc ignition. Figure 7 (b) is a graph showing the change in arc resistance during the entire closing operation; Figure 8 This is a VFTO characteristic analysis diagram of the closing operation in an embodiment of the present invention, wherein, Figure 8(a) is a time-domain signal diagram of VFTO during the closing operation. Figure 8 (b) is a frequency domain signal diagram of the closing operation; Figure 9 This is a VFTO characteristic analysis diagram of a single breakdown during closing in an embodiment of the present invention, wherein, Figure 9 (a) is the VFTO time-domain signal diagram of a single breakdown during closing. Figure 9 (b) is a frequency domain signal diagram of VFTO during a single breakdown when the circuit is closed; Figure 10 This is a VFTO characteristic analysis diagram of the tripping operation in an embodiment of the present invention, wherein, Figure 10 (a) is a time-domain signal diagram of VFTO during the tripping operation. Figure 10 (b) is a frequency domain signal diagram of the VFTO operation; Figure 11 This is a VFTO characteristic analysis diagram of a single breakdown during circuit breaker tripping in an embodiment of the present invention, wherein, Figure 11 (a) is the VFTO time-domain signal diagram of a single breakdown during circuit breaker tripping. Figure 11 (b) is a frequency domain signal diagram of VFTO during a single breakdown when the circuit breaker is tripped. Detailed Implementation

[0019] The following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0021] The terms "comprising" or "including" as used in this invention mean that the element preceding the term encompasses the element listed after the term, and do not exclude the possibility of encompassing other elements. Terms such as "inner," "outer," "upper," and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In this invention, unless otherwise explicitly specified and limited, the term "attached" and similar terms should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Example: A nonlinear circuit simulation method that considers the time-varying inductance and capacitance effects of electric arcs, such as... Figure 1 As shown, it includes the following steps: S1: Establish a dynamic arc comprehensive equivalent model, including time-varying arc resistance, time-varying arc inductance, and time-varying gap capacitance; The time-varying arc resistance is modeled using a piecewise approach, specifically including: A hyperbolic resistance model is used in the pre-breakdown stage; A fixed-value resistor model is used in the stable arc-burning stage; The Mayr model is used during the arc extinction phase.

[0023] The time-varying arc inductance is modeled using Martin's formula, and is expressed as: ; in, The arc path length varies with time and is equal to the gap distance between the moving and stationary contacts of the disconnecting switch, and is determined by the movement speed of the contacts and time.

[0024] Arc channel length Specifically, it is expressed as follows: During the tripping operation: ; During the closing operation: ; in, The opening speed of the moving contact. The closing speed of the moving contact. This refers to the initial distance between the moving and stationary contacts of the isolating switch.

[0025] The time-varying gap capacitance is expressed as: ; in, This represents the duration of the contact movement process.

[0026] S2: Dynamically couple the time-varying arc inductance and time-varying gap capacitance with the mechanical motion characteristics of the disconnecting switch contacts, wherein the mechanical motion characteristics include contact movement speed, movement time, and gap distance; S3: The reignition and extinction process of the electric arc is controlled by a hybrid criterion: the reignition of the electric arc is determined based on the gas dielectric theory, and the extinction of the electric arc is determined based on the energy balance theory. Determining whether an electric arc will reignite based on the gas dielectric theory specifically includes: Real-time calculation of the recovery voltage of the disconnector contact gap Critical breakdown voltage at the current gap distance ; Compare the recovery voltage with the critical breakdown voltage; When the condition is met If the arc reignites, it is determined that the arc has reignited; otherwise, the arc remains extinguished. Among them, the critical breakdown voltage It is linearly proportional to the gap length of the disconnecting switch contacts.

[0027] Critical breakdown voltage Specifically, it is expressed as follows: When the disconnector is tripped, it is indicated as follows: ; When closing the disconnector switch, it is indicated as follows: ; in, This represents the breakdown field strength per unit length of the disconnector gap. For the operating speed of the disconnect switch, This is the maximum opening distance of the switch contacts. For time.

[0028] Determining whether an electric arc has extinguished based on energy balance theory specifically includes: Real-time monitoring of the current flowing through the arc channel ; Set current change rate threshold ; An electric arc is considered extinguished when all of the following conditions are met: (1) Current zero-crossing condition: ,in, This is the simulation time step; (2) Current change rate condition: .

[0029] S4: Construct a simulation circuit in electromagnetic transient simulation software that includes the dynamic arc comprehensive equivalent model to simulate multiple breakdown phenomena during the operation of the disconnecting switch; The electromagnetic transient simulation software is ATP-EMTP, and the dynamic control and logical judgment of arc resistance, inductance and capacitance are realized through the MODELS module.

[0030] S5: Acquire and analyze the time-domain waveform and spectral characteristics of ultra-fast transient overvoltages to achieve accurate prediction and analysis of VFTO.

[0031] Example 1: This embodiment only models GIS switchgear and does not consider the impact of transformer equipment. Figure 2 In this diagram, L1 and L2 represent GIS busbars, C1 is the equivalent ground capacitance of the incoming bushing, C2 is the equivalent ground capacitance of the insulator near the disconnecting switch, C3 is the equivalent ground capacitance of the circuit breaker, and C4 is the equivalent ground capacitance of the outgoing bushing. L ECT and C EVT Let represent the equivalent inductance and equivalent capacitance of the current sensor, respectively. The voltage and current sensors are placed at the outlet bushing to measure the voltage and current at this location. Based on the above circuit model topology and the arc reignition model, a circuit is established using the electromagnetic transient software PSCAD / EMTDC as follows: Figure 3 A GIS electromagnetic transient simulation model.

[0032] like Figure 4 For the entire arc control module, the `choose1` signal controls the opening and closing selection of the entire system. When `choose1` is 1, the system closes the isolating switch; when `choose1` is 0, the system opens the isolating switch. The following example uses arc resistance control during closing. A two-input comparator and edge detector 1 are used to compare the voltage difference between the moving and stationary contacts of the isolating switch with the SF6 breakdown voltage between the moving and stationary contacts. The signal S1 output by edge detector 1 serves as the set signal S of the SR latch. A current zero-crossing detector and edge detector 2 are used to detect the current. The signal R1 output by edge detector 2 serves as the reset signal R of the SR latch. The SR latch output signal Q1 is initially set to 0. Figure 5As shown in (a), when the voltage difference between the moving and stationary contacts is greater than the SF6 breakdown voltage between them, S1 will output a pulse with an amplitude of 1. At this time, R1 is 0, and Q1 is set to 1, thus initiating the pre-breakdown and stable arc-burning stage of the arc. Until the arc current crosses zero, R1 outputs a pulse with an amplitude of 1. At this time, S1 is 0, and Q1 is reset to 0 again, marking the end of stable arc-burning and the beginning of the arc-extinguishing stage. After the arc extinguishing is complete, the system waits for the next S1 to output a set signal. The waveform of the Q1 signal during the entire closing process is as follows: Figure 5 As shown in (b), each pulse represents one arc combustion.

[0033] Each rising edge of Q1 occurs when the voltage difference between the moving and stationary contacts of the disconnector begins to exceed the SF6 breakdown voltage between them. Q1 then outputs Q3 via the reset system. Figure 6 As shown in (b), Q3 is reset to a time signal starting from 0 at each rising edge of Q1. Figure 6 As shown in (a), Q2 changes from low level to high level at 0.1s, at which time the switch begins to close.

[0034] Use Q3 as the time input signal for calculating the arc resistance value, such as Figure 7 (a) shows the resistance change curve of the arc during a single arc ignition. At the rising edge of Q1, the pre-breakdown stage begins. When the calculated pre-breakdown arc resistance is greater than 10... 12 When Ω, the arc resistance remains at 10. 12 Ω, when the calculated pre-breakdown arc resistance is less than 10 12 Afterward, the arc resistance value drops rapidly, reaching 0.5Ω, at which point it enters the stable arc-burning stage and remains constant at 0.5Ω. This continues until the falling edge of Q1 arrives, at which point the arc resistance at the time of arc extinction is called back, until the arc resistance rises to 10Ω. 12 At Ω, the single arcing process ends, maintaining an arc resistance of 10. 12 Ω remains unchanged, waiting for the next rising edge of Q1 to enter the next arc pre-breakdown. The entire process repeats until the disconnecting switch stops operating. Figure 7 As shown in (b).

[0035] Example 2: Simulation was performed on the established GIS model. The VFTO waveform at the outgoing bushing during closing is as follows: Figure 8 As shown in (a), as the distance between the moving and stationary contacts gradually decreases during closing, the breakdown voltage of the SF6 gas gradually decreases, the number of gas breakdowns increases accordingly, and the number of pulses increases accordingly. The overall voltage waveform shows a continuous stepped shape, and the pulse sequence distribution shows a characteristic of being sparse at the beginning and dense at the end. A total of 22 obvious air gap breakdowns occurred during the entire closing process, and the maximum amplitude of VFTO was 430.34kV. Figure 8 (b) It can be seen that the main electromagnetic interference frequencies of VFTO during the closing process are concentrated at 2.7MHz, 7.2MHz, 30.1MHz, and 42.9MHz.

[0036] Amplifying the breakdown with the largest VFTO amplitude during the closing operation yields the following result: Figure 9 The voltage waveform shown in (a) is a damped oscillating wave, where the VFTO waveform of a single arc is a voltage waveform. Figure 9 (b) It can be seen that the signal spectrum of a single breakdown mainly has peaks at 2.9MHz and 7.1MHz.

[0037] The VFTO waveform of the outgoing bushing during tripping is as follows: Figure 10 As shown in (a), when the disconnecting switch is opened, the moving contact begins to move away from the stationary contact, and the air gap distance between them gradually increases, causing the breakdown voltage of the gap to gradually rise. The number of gas breakdowns decreases accordingly, and the pulse sequence distribution shows a denser initial phase followed by a sparser later phase. A total of 19 significant air gap breakdowns occur during the entire opening process. Similar to the closing process, the overall voltage waveform during opening also exhibits a continuous stepped shape. The maximum amplitude of VFTO during opening is 440.13kV. Figure 10 (b) It can be seen that the spectrum of VFTO during the opening of the circuit breaker has peaks at 2.7MHz, 7.2MHz, 30MHz and 42.9MHz.

[0038] Similarly, by amplifying the breakdown with the largest VFTO amplitude during the tripping operation, we can obtain the following: Figure 11 The voltage waveform shown in (a) is compared with the voltage waveform of a single arc ignition during closing. Except for the difference in voltage amplitude, the two waveforms show roughly the same trend. Figure 11 (b) It can be seen that the signal spectrum of a single breakdown during the opening has peaks at 2.5MHz and 7.1MHz, which is lower than the main frequency during the closing.

[0039] The time intervals between the first ten breakdowns when the disconnecting switch is closed and the time intervals between the last ten breakdowns when it is opened are statistically analyzed. The interval number 1 represents the time from the first breakdown to the second breakdown when the switch is closed and the time from the second-to-last breakdown to the last breakdown when the switch is opened. The results are shown in Table 1.

[0040] Table 1. Statistical table of time intervals between different breakdowns of disconnecting switches.

[0041] As shown in Table 1, the time interval between each breakdown during closing is significantly shorter than the time interval between each breakdown during opening. This is because the gas breakdown voltage in the disconnector gap is greater in the later stage of opening than in the early stage of closing. At this time, the voltage difference between the moving and stationary contacts needs a longer time to exceed the breakdown voltage of the SF6 gas. Therefore, the gas breakdown interval during opening is longer than that during closing, which is also the reason why the total gas breakdown time during opening is longer than that during closing.

[0042] Therefore, this invention employs a nonlinear circuit simulation method that considers the time-varying inductance and capacitance effects of the arc. By constructing a dynamic arc equivalent model integrating resistance, inductance, and capacitance, and dynamically coupling electrical parameters with the mechanical motion characteristics of the disconnecting switch, it precisely controls the reignition and extinction processes of the arc using a hybrid criterion based on gas dielectric theory and energy balance theory. This achieves a more accurate and comprehensive simulation and prediction of the ultra-fast transient overvoltage (VFTO) generated by the operation of GIS disconnecting switches. This effectively overcomes the shortcomings of traditional models that only consider arc resistance or static parameters, providing crucial technical support and a reliable data foundation for the insulation coordination design of GIS equipment, electromagnetic compatibility assessment, and anti-interference optimization of secondary equipment in smart substations.

[0043] 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 nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of electric arcs, characterized in that, Includes the following steps: S1: Establish a dynamic arc comprehensive equivalent model, including time-varying arc resistance, time-varying arc inductance, and time-varying gap capacitance; S2: Dynamically couple the time-varying arc inductance and time-varying gap capacitance with the mechanical motion characteristics of the disconnecting switch contacts, wherein the mechanical motion characteristics include contact movement speed, movement time, and gap distance; S3: The reignition and extinction process of the electric arc is controlled by a hybrid criterion: the reignition of the electric arc is determined based on the gas dielectric theory, and the extinction of the electric arc is determined based on the energy balance theory. S4: Construct a simulation circuit in electromagnetic transient simulation software that includes the dynamic arc comprehensive equivalent model to simulate multiple breakdown phenomena during the operation of the disconnecting switch; S5: Acquire and analyze the time-domain waveform and spectral characteristics of ultra-fast transient overvoltages to achieve accurate prediction and analysis of VFTO.

2. The nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 1, characterized in that, The time-varying arc resistance is modeled using a piecewise approach, specifically including: A hyperbolic resistance model is used in the pre-breakdown stage; A fixed-value resistor model is used in the stable arc-burning stage; The Mayr model is used during the arc extinction phase.

3. The nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 2, characterized in that, The time-varying arc inductance is modeled using Martin's formula, and is expressed as: ； in, The arc path length varies with time and is equal to the gap distance between the moving and stationary contacts of the disconnecting switch, and is determined by the movement speed of the contacts and time.

4. The nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 3, characterized in that, Arc channel length Specifically, it is expressed as follows: During the tripping operation: ; During the closing operation: ; in, The opening speed of the moving contact. The closing speed of the moving contact. This refers to the initial distance between the moving and stationary contacts of the isolating switch.

5. The nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 4, characterized in that, The time-varying gap capacitance is expressed as: ； in, This represents the duration of the contact movement process.

6. The nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 5, characterized in that, Determining whether an electric arc will reignite based on the gas dielectric theory specifically includes: Real-time calculation of the recovery voltage of the disconnector contact gap Critical breakdown voltage at the current gap distance ; Compare the recovery voltage with the critical breakdown voltage; When the condition is met If the arc reignites, it is determined that the arc has reignited; otherwise, the arc remains extinguished. Among them, the critical breakdown voltage It is linearly proportional to the gap length of the disconnecting switch contacts.

7. The nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 6, characterized in that, During the disconnection switch tripping operation, the critical breakdown voltage is... Represented as: ； in, This refers to the breakdown voltage per unit length of the disconnector gap. For the operating speed of the disconnect switch, For time.

8. The nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 7, characterized in that, During the closing operation of the disconnecting switch, the critical breakdown voltage Represented as: ； in, This represents the maximum opening distance of the switch contacts.

9. A nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 8, characterized in that, Determining whether an electric arc has extinguished based on energy balance theory specifically includes: Real-time monitoring of the current flowing through the arc channel ; Set current change rate threshold ; An electric arc is considered extinguished when all of the following conditions are met: (1) Current zero-crossing condition: ,in, This is the simulation time step; (2) Current change rate condition: .

10. A nonlinear circuit simulation method considering the time-varying inductance and capacitance effects of an electric arc as described in claim 9, characterized in that: The electromagnetic transient simulation software is ATP-EMTP, and the dynamic control and logical judgment of arc resistance, inductance and capacitance are realized through the MODELS module.

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