Method, device and equipment for evaluating post-arc thermal interruption performance of circuit breaker and medium
By constructing a multi-physics coupled arc model and fitting the Mayr model, the post-arc thermal interruption performance of the circuit breaker under near-zone fault conditions is evaluated, which solves the problem of lack of theoretical basis for the optimization design of existing circuit breakers and realizes efficient performance evaluation and optimization design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-20
- Publication Date
- 2026-04-10
AI Technical Summary
Existing technologies lack effective methods to accurately evaluate the post-arc thermal interruption performance of circuit breakers under near-zone fault conditions, resulting in a lack of theoretical basis for circuit breaker optimization design.
A multiphysics coupled arc model of the circuit breaker was constructed. Arc current and voltage data were obtained through arc simulation. The Mayr model was used to fit the arc time constant and energy dissipation coefficient to predict the post-arc current value. The actual value was compared with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker.
This enables quantitative evaluation of the thermal interruption performance of circuit breakers, reduces testing costs and time, provides a theoretical basis for circuit breaker design and optimization, and improves the safety and reliability of power systems.
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Figure CN121835206A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of breaking technology of high-voltage switchgear, and in particular to a circuit breaker post-arc thermal breaking performance evaluation method, device, equipment and medium. BACKGROUND
[0002] As the main switching device for breaking and connecting electrical contact in the power system, the high-voltage gas circuit breaker shoulders the heavy responsibility of quickly and reliably cutting off the fault current, limiting the fault range and preventing large-scale power failure accidents. Its safety and reliability is crucial to the safe and stable operation of the entire power system. The breaking process of the circuit breaker usually goes through an arc burning stage and an arc recovery stage. In the arc burning stage, the arc burns fiercely under the action of large current joule heat, the arc temperature in the arc chamber is extremely high, and the energy exchange is strong. In the post-arc stage, the circuit breaker experiences a competitive process of recovery voltage rising and dielectric strength recovery.
[0003] The short-circuit fault occurring on the overhead line within a few kilometers of the circuit breaker terminal is called a short-line fault (SLF). L90 short-line fault is the worst condition for circuit breaker breaking, although its short-circuit current is slightly lower than the rated short-circuit current, but under the action of the line, a high initial recovery voltage rising rate (RRRV) will occur, which increases the post-arc current and increases the breaking risk. At present, there is a lack of an effective method to accurately evaluate the post-arc thermal breaking performance of the circuit breaker under the short-line fault, so as to provide a theoretical basis for the optimization design of the circuit breaker. SUMMARY
[0004] Therefore, it is necessary to propose a circuit breaker post-arc thermal breaking performance evaluation method, device, equipment and medium aiming at the above problems, to solve the technical problem that the post-arc thermal breaking performance of the circuit breaker under the short-line fault condition is difficult to be effectively evaluated.
[0005] The present application provides a circuit breaker post-arc thermal breaking performance evaluation method, which comprises: constructing a multi-physics field coupled arc model of the circuit breaker, and carrying out arc simulation to obtain zero-arc current and arc voltage data, wherein the multi-physics field includes temperature field, airflow field and electric field of the circuit breaker; based on the zero-arc current and arc voltage data, the Mayr model is used to fit the zero-arc time constant θ and the arc energy dissipation coefficient Q; based on the zero-arc time constant θ and the energy dissipation coefficient Q as parameters of the post-arc model, the post-arc current value under different recovery voltage rising rates is predicted; the corresponding recovery voltage rising rate when the post-arc current value does not decrease to zero within a preset time is determined as the critical recovery voltage rising rate; determine the actual recovery voltage rise rate across the circuit breaker under the near-zone fault condition based on the circuit parameters of the preset near-zone fault condition; compare the actual recovery voltage rise rate with the critical recovery voltage rise rate, and evaluate the thermal interruption performance of the circuit breaker.
[0006] Further, the determination of the actual recovery voltage rise rate across the circuit breaker under the near-zone fault condition based on the circuit parameters of the preset near-zone fault condition specifically comprises: determining a first peak peak voltage of the oscillation voltage on the line side; determining an overall recovery voltage rise time according to the power supply side time delay and the rise time of the line side to the first peak peak voltage; determining an overall recovery voltage peak value across the circuit breaker according to the sum of the power supply side recovery voltage value, the initial transient recovery voltage and the line side recovery voltage value; determining the actual recovery voltage rise rate across the circuit breaker according to the ratio of the overall recovery voltage peak value across the circuit breaker to the overall recovery voltage rise time.
[0007] Further, the first peak peak voltage of the oscillation voltage on the line side is determined according to the following formula:
[0008] wherein, is the rated voltage of the circuit breaker, is the near-zone fault breaking current, is the rated short-circuit breaking current, is a peak coefficient, is the first peak peak voltage of the oscillation voltage on the line side.
[0009] Further, the Mayr model formula is:
[0010] wherein, is the arc conductance, is the arc voltage, is the arc current, is the arc time constant, is the arc energy dissipation coefficient.
[0011] Further, the comparison of the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker comprises: comparing the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate whether the thermal breakdown of the circuit breaker occurs; if the actual recovery voltage rise rate is greater than or equal to the critical recovery voltage rise rate, the thermal breakdown occurs, and the thermal interruption of the circuit breaker fails. If the actual recovery voltage rise rate is less than the critical recovery voltage rise rate, the circuit breaker can successfully open the circuit.
[0012] Further, the overall recovery voltage rise time is determined according to the following formula:
[0013]
[0014] wherein, is the current rise rate at the zero-crossing time, Z is the line wave impedance, is the time delay on the power supply side, is the rise time of the first peak voltage on the line side, is the overall recovery voltage rise time, is the first wave peak peak voltage of the oscillation voltage on the line side.
[0015] Further, the overall recovery voltage peak value across the circuit breaker is determined according to the following formula:
[0016]
[0017] wherein, is the bus voltage drop under the initial transient recovery voltage effect, is the recovery voltage rise rate on the power supply side, is the time delay on the power supply side, is the multiplier coefficient, is the peak coefficient, is the overall recovery voltage rise time, is the first wave peak peak voltage of the oscillation voltage on the line side, is the overall recovery voltage peak value across the circuit breaker.
[0018] The embodiments of the present application also provide an evaluation device for post-arc thermal interruption performance of a circuit breaker, the device comprising: a simulation unit configured to construct a multi-physical field coupled arc model of the circuit breaker, and develop arc simulation to obtain pre-zero arc current and arc voltage data, wherein the multi-physical field comprises a temperature field, an airflow field and an electric field of the circuit breaker; a fitting unit configured to fit the pre-zero arc time constant θ and the arc energy dissipation coefficient Q based on the pre-zero arc current and arc voltage data by using a Mayr model; a prediction unit configured to predict post-arc current values under different recovery voltage rise rates based on the pre-zero arc time constant θ and the energy dissipation coefficient Q as parameters of a post-arc model. The screening unit is configured to determine a critical recovery voltage rise rate as a recovery voltage rise rate corresponding to an arc-after current value that does not decrease to zero within a preset time. The determining unit is configured to determine an actual recovery voltage rise rate across the circuit breaker under the near-zone fault condition based on circuit parameters of the preset near-zone fault condition. The evaluation unit is configured to compare the actual recovery voltage rise rate with the critical recovery voltage rise rate, and evaluate the thermal interruption performance of the circuit breaker.
[0019] The embodiments of the present application further provide a computer device, which comprises a memory and a processor, and the memory stores a computer program, and the computer program is executed by the processor to enable the processor to perform the following steps: The multi-physics field coupled arc model of the circuit breaker is constructed, and arc simulation is performed to obtain pre-zero arc current and arc voltage data, and the multi-physics field comprises a temperature field, an airflow field and an electric field of the circuit breaker. Based on the pre-zero arc current and arc voltage data, the Mayr model is adopted to fit to obtain the pre-zero arc time constant θ and the arc energy dissipation coefficient Q. Based on the pre-zero arc time constant θ and the energy dissipation coefficient Q as parameters of a post-zero arc model, the arc-after current value under different recovery voltage rise rates is predicted. The recovery voltage rise rate corresponding to an arc-after current value that does not decrease to zero within a preset time is determined as a critical recovery voltage rise rate. Based on circuit parameters of the preset near-zone fault condition, the actual recovery voltage rise rate across the circuit breaker under the near-zone fault condition is determined. The actual recovery voltage rise rate is compared with the critical recovery voltage rise rate, and the thermal interruption performance of the circuit breaker is evaluated.
[0020] The embodiments of the present application further provide a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to enable the processor to perform the following steps: The multi-physics field coupled arc model of the circuit breaker is constructed, and arc simulation is performed to obtain pre-zero arc current and arc voltage data, and the multi-physics field comprises a temperature field, an airflow field and an electric field of the circuit breaker. Based on the pre-zero arc current and arc voltage data, the Mayr model is adopted to fit to obtain the pre-zero arc time constant θ and the arc energy dissipation coefficient Q. Based on the pre-zero arc time constant θ and the energy dissipation coefficient Q as parameters of a post-zero arc model, the arc-after current value under different recovery voltage rise rates is predicted. The recovery voltage rise rate corresponding to an arc-after current value that does not decrease to zero within a preset time is determined as a critical recovery voltage rise rate. Determine the actual recovery voltage rise rate at both ends of the circuit breaker under the near-zone fault condition based on the circuit parameters of the preset near-zone fault condition; Compare the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker.
[0021] The embodiments of the present application have the following beneficial effects: The present application accurately simulates the physical phenomena in the breaking process of the circuit breaker by using the multi-physical field coupling arc model, simulates the temperature field, airflow field and electric field distribution in the breaking process of the circuit breaker, and obtains the pre-arc current and arc voltage data; the Mayr model is used to fit the pre-arc current and arc voltage data, the arc time constant and arc energy dissipation coefficient are obtained, and the accuracy of parameter determination is improved; the post-arc current and the critical recovery voltage rise rate are predicted: the post-arc current under different recovery voltage rise rates is predicted based on the fitting parameters, and the critical recovery voltage rise rate is determined; by comparing the actual recovery voltage rise rate with the critical recovery voltage rise rate, it is evaluated whether the thermal breakdown of the circuit breaker will occur, so as to judge its breaking performance; the quantitative evaluation of the thermal interruption performance of the circuit breaker is realized, which provides a theoretical basis for the design and optimization of the circuit breaker, and reduces the test cost and time. BRIEF DESCRIPTION OF DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.
[0023] Among them: Figure 1 The flowchart of the evaluation method of the post-arc thermal interruption performance of the circuit breaker in one embodiment; Figure 2 The simplified single-phase circuit diagram of the near-zone fault test in one embodiment in which the power supply side has ITRV and the line side has time delay; Figure 3 The arc simulation model diagram of the 126kV pressure gas circuit breaker in one embodiment; Figure 4 The post-arc current distribution diagram of the circuit breaker when breaking the L90 fault current in one embodiment; Figure 5 The structural diagram of the evaluation device of the post-arc thermal interruption performance of the circuit breaker in one embodiment; Figure 6 The structural diagram of the computer equipment in one embodiment; Figure 7 The structural diagram of the computer readable storage medium in one embodiment. DETAILED DESCRIPTION
[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.
[0025] In the embodiments of the present application, a method for evaluating post-arc thermal interruption performance of a circuit breaker is provided. Please refer to Figure 1 , Figure 1 FIG. 1 is a flowchart of the method for evaluating post-arc thermal interruption performance of a circuit breaker in an embodiment. The method for evaluating post-arc thermal interruption performance of a circuit breaker includes steps S1 to S6.
[0026] In step S1, a multi-physical field coupled arc model of the circuit breaker is constructed, and arc simulation is performed to obtain pre-zero arc current and arc voltage data. The multi-physical field includes a temperature field, a gas flow field and an electric field of the circuit breaker. In some embodiments, a multi-physical field coupled arc model of a gas circuit breaker is constructed, and the physical field includes a temperature field, a gas flow field and an electric field of the circuit breaker. A geometric model is constructed according to the actual structure of the circuit breaker, material properties are assigned to the geometric model, and insulation gas parameters (such as SF6 gas parameters) are imported. According to the actual working condition, the short-circuit current effective value is injected, arc simulation is performed, and pre-zero arc current and arc voltage data are obtained.
[0027] In step S2, based on the pre-zero arc current and arc voltage data, a Mayr model is used to fit to obtain the pre-zero arc time constant θ and the arc energy dissipation coefficient Q. In some embodiments, the Mayr model formula is as follows:
[0028] wherein, is the arc conductance, is the arc voltage, is the arc current, is the arc time constant, is the arc energy dissipation coefficient.
[0029] In step S3, the pre-zero arc time constant θ and the energy dissipation coefficient Q are used as parameters of a post-arc model to predict post-arc current values under different recovery voltage rise rates. In step S4, the corresponding recovery voltage rise rate at which the post-arc current value does not decrease to zero within a preset time is determined as a critical recovery voltage rise rate. Specifically, the preset time can be 20 microseconds, with an arc time constant before zero and an arc energy dissipation coefficient As a parameter of the post-arc model, the post-arc current value within 20 microseconds after the current zero is predicted by applying different rates of rise of recovery voltage (RRRV); the corresponding rate of rise of recovery voltage, at which the post-arc current does not decrease to zero within 20 microseconds, is determined as the critical rate of rise of recovery voltage.
[0030] Step S5, based on the preset circuit parameters of the near-zone fault working condition, determining the actual rate of rise of recovery voltage across the circuit breaker under the near-zone fault working condition; In some embodiments, the step of determining the actual rate of rise of recovery voltage across the circuit breaker under the near-zone fault working condition based on the preset circuit parameters of the near-zone fault working condition specifically comprises steps S51 to S54: Step S51, determining the first peak peak voltage of the line-side oscillation voltage; Specifically, the first peak peak voltage of the line-side oscillation voltage is determined according to the following formula:
[0031] wherein, is the rated voltage of the circuit breaker, is the near-zone fault breaking current, is the rated short-circuit breaking current, is the peak coefficient, is the first peak peak voltage of the line-side oscillation voltage.
[0032] Step S52, determining the overall rate of rise of recovery voltage according to the power supply side time delay and the line side rise time to the first peak peak voltage; Specifically, the overall rate of rise of recovery voltage is determined according to the following formula:
[0033]
[0034] wherein, is the current rise rate at the zero-crossing moment, and Z is the line wave impedance, is the power supply side time delay, is the line side rise time to the first peak voltage, is the overall rate of rise of recovery voltage, is the first peak peak voltage of the line-side oscillation voltage.
[0035] Step S53, determining the overall recovery voltage peak value across the circuit breaker according to the sum of the power supply side recovery voltage value, the initial transient recovery voltage and the line side recovery voltage value; Specifically, the overall recovery voltage peak value across the circuit breaker is determined according to the following formula:
[0036]
[0037] wherein, is the bus voltage drop under the initial transient recovery voltage, is the power supply side recovery voltage rise rate, is the power supply side time delay, is the multiplier coefficient, is the peak coefficient, is the overall recovery voltage rise time, is the first peak peak voltage of the line side oscillation voltage, is the overall recovery voltage peak value across the circuit breaker.
[0038] Step S54, determining the actual recovery voltage rise rate across the circuit breaker according to the ratio of the overall recovery voltage peak value across the circuit breaker and the overall recovery voltage rise time.
[0039] In some embodiments, the comparison of the actual recovery voltage rise rate and the critical recovery voltage rise rate evaluates the thermal interruption performance of the circuit breaker, including: comparing the actual recovery voltage rise rate and the critical recovery voltage rise rate to evaluate whether the thermal breakdown of the circuit breaker occurs; if the actual recovery voltage rise rate is greater than or equal to the critical recovery voltage rise rate, the thermal breakdown occurs, and the thermal interruption of the circuit breaker fails; if the actual recovery voltage rise rate is less than the critical recovery voltage rise rate, the circuit breaker can successfully thermal open.
[0040] The evaluation method of the arc-after thermal interruption performance of the circuit breaker of the present application is further verified below in combination with specific cases: The most severe near-zone fault is taken as the calculation condition, i.e. single-phase grounding in a neutral-point grounded system, and the first opening factor is equal to 1. The near-zone fault condition is L90, there is a 0.2 μs time delay on the line side, there is a 2 μs time delay on the power supply side and there is an ITRV (initial transient recovery voltage). The simplified single-phase circuit is shown in Figure 2 , Figure 2A simplified single-phase circuit diagram for near-zone fault test with ITRV on the power side and time delay on the line side is shown in one embodiment. The transient recovery voltage (TRV) of the circuit breaker under near-zone fault condition is the combination of the voltage on the power side and the voltage on the line side. Since the voltage on the power side and the voltage on the line side are in opposite directions, the TRV can be expressed by absolute value as:
[0041] The first peak voltage of the oscillating voltage on the line side can be calculated by wherein, is the rated voltage of the circuit breaker, is the near-zone fault breaking current, is the rated short-circuit breaking current, is the peak coefficient, and is the first peak voltage of the oscillating voltage on the line side. In the present case, the peak coefficient k is 1.6 when the rated voltage level is 126 kV.
[0042] The rise time of the first peak voltage on the line side is related to the line wave impedance and the current rise rate at the zero-crossing time . With the superposition of the harmonic components in the near-zone fault current, the current rise rate at the zero-crossing time is significantly increased, thereby reducing the rise time of the first peak voltage on the line side and the overall recovery voltage rise time tT.
[0043] The overall recovery voltage rise time is determined according to the following formula:
[0044]
[0045] wherein, is the current rise rate at the zero-crossing time, Z is the line wave impedance, is the time delay on the power side, is the rise time of the first peak voltage on the line side, is the overall recovery voltage rise time, is the first peak voltage of the oscillating voltage on the line side. In the present case, the line wave impedance Z is 450 Ω, and the time delay on the power side is 0.2 μs.
[0046] When breaking a 126 kV near-zone fault, the recovery voltage rise rate on the power side of the circuit breaker is 1.8 kV / μs, the duration of the initial transient recovery voltage (ITRV) is 0.4 μs, and the bus voltage drop under the ITRV is:
[0047] In this case The multiplier is equal to 0.046 kV / kA. The peak coefficient is 1.4.
[0048] The first peak voltage reached by the transient recovery voltage across the circuit breaker before the line-side oscillation voltage disappears is mainly determined by the line side. The power supply side delay is 2μs. The overall recovery voltage peak across the circuit breaker is determined using the following formula:
[0049] Therefore, the initial recovery voltage rise rate on both sides of the circuit breaker under near-zone fault conditions can be derived as follows:
[0050] in, This represents the peak value of the overall recovery voltage across the circuit breaker. The overall recovery voltage rise time.
[0051] Table 1 below shows the calculated actual recovery voltage rise rate data. When the 126kV circuit breaker interrupts the L90 near-zone fault, the actual recovery voltage rise rate is 7.02 kV / μs.
[0052] Table 1:
[0053] Furthermore, an arc simulation was conducted on a 126kV gas-fired circuit breaker, using SF6 gas as the arc-extinguishing medium, a rated short-circuit current of 40kA, and a charging pressure of 0.6MPa. The arc simulation model structure is as follows: Figure 3 The diagram shows a simulation model of an arc-generating 126kV air-cooled circuit breaker in one embodiment. Arc simulation of a near-zone fault L90 was conducted to obtain arc voltage and current data in the zero-zone. The arc time constant before zero-zone was then fitted using the Mayr model. and arc energy dissipation coefficient And predicted the post-arc current distribution of the circuit breaker as follows Figure 4 As shown, Figure 4 The image shows a simulation model of an arc in a 126kV pneumatic circuit breaker in one embodiment, where the corresponding critical RRRV is 9.19 kV / μs.
[0054] Therefore, the predicted critical recovery voltage rise rate of 9.19 kV / μs is higher than the actual recovery voltage rise rate of 7.02 kV / μs, indicating that the circuit breaker can successfully thermally interrupt the circuit.
[0055] The technical scheme of the embodiment can effectively evaluate the post-arc thermal interruption performance of the circuit breaker under the near-zone fault condition, provide a theoretical reference for the breaking performance of the gas medium and the optimal design of the circuit breaker, improve the safety and reliability of the power system, and obtain the post-arc current curve under any RRRV through only one multi-physical field simulation, thereby significantly reducing the test times and costs. The "critical RRRV" is quantitatively output, which can be directly compared with the actual RRRV of the system, the "success / failure" probability boundary is given, and the safety factor design is guided. The standard Mayr model is adopted, and the commercial CFD-EMT joint simulation platform is compatible, thereby facilitating engineering promotion.
[0056] In the embodiment of the present application, an evaluation device for post-arc thermal interruption performance of a circuit breaker is provided. Referring to Figure 5 , Figure 5 FIG. 1 is a structural diagram of an evaluation device for post-arc thermal interruption performance of a circuit breaker in an embodiment. The evaluation device for post-arc thermal interruption performance of a circuit breaker includes a simulation unit 201, a simulation unit 202, a prediction unit 203, a screening unit 204, a determination unit 205, and an evaluation unit 206.
[0057] The simulation unit 201 is configured to construct a multi-physical field coupled arc model of the circuit breaker and perform arc simulation to obtain pre-zero arc current and arc voltage data. The multi-physical field includes a temperature field, a gas flow field, and an electric field of the circuit breaker. The fitting unit 202 is configured to fit the pre-zero arc time constant θ and the arc energy dissipation coefficient Q by using a Mayr model based on the pre-zero arc current and arc voltage data. The prediction unit 203 is configured to predict the post-arc current value under different recovery voltage rise rates based on the pre-zero arc time constant θ and the energy dissipation coefficient Q as parameters of the post-arc model. The screening unit 204 is configured to determine the critical recovery voltage rise rate as the corresponding recovery voltage rise rate under which the post-arc current value does not decrease to zero within a preset time. The determination unit 205 is configured to determine the actual recovery voltage rise rate of the circuit breaker under the near-zone fault condition based on the preset circuit parameters of the near-zone fault condition. The evaluation unit 206 is configured to compare the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker.
[0058] In some embodiments, the determination unit 205 is further configured to determine a first wave peak voltage of the line side oscillation voltage. The overall recovery voltage rise time is determined according to the power source side time delay and the rise time of the line side to the first wave peak voltage. determining an overall recovery voltage peak value across the circuit breaker according to a sum of the power source side recovery voltage value, the initial transient recovery voltage, and the line side recovery voltage value; determining the actual recovery voltage rise rate across the circuit breaker according to a ratio of the overall recovery voltage peak value across the circuit breaker and the overall recovery voltage rise time.
[0059] In some embodiments, the determining unit 205 is further configured to determine the first peak value of the line side oscillation voltage according to the following formula:
[0060] wherein, is a rated voltage of the circuit breaker, is a near-zone fault breaking current, is a rated short-circuit breaking current, is a peak coefficient, is the first peak value of the line side oscillation voltage.
[0061] In some embodiments, the fitting unit 202 is further configured to determine the Mayr model formula as:
[0062] wherein, is an arc conductance, is an arc voltage, is an arc current, is an arc time constant, is an arc energy dissipation coefficient.
[0063] In some embodiments, the evaluating unit 206 is further configured to compare the actual recovery voltage rise rate with the critical recovery voltage rise rate, and evaluate whether the circuit breaker is subjected to thermal breakdown; if the actual recovery voltage rise rate is greater than or equal to the critical recovery voltage rise rate, the thermal breakdown occurs, and the circuit breaker fails in thermal interruption; if the actual recovery voltage rise rate is less than the critical recovery voltage rise rate, the circuit breaker can successfully break down thermally.
[0064] In some embodiments, the determining unit 205 is further configured to determine the overall recovery voltage rise time according to the following formula:
[0065]
[0066] wherein, is a current rise rate at a zero-crossing moment, and Z is a line wave impedance, a time delay for the power supply side, a rise time for the line side to reach the first peak voltage, a total recovery voltage rise time, a first peak voltage of the oscillating voltage on the line side.
[0067] In some embodiments, the determining unit 205 is further configured to determine the total recovery voltage peak value across the circuit breaker according to the following formula:
[0068]
[0069] wherein, a bus voltage drop under the initial transient recovery voltage effect, a recovery voltage rise rate for the power supply side, a time delay for the power supply side, a multiplier coefficient, a peak coefficient, a total recovery voltage rise time, a first peak voltage of the oscillating voltage on the line side, a total recovery voltage peak value across the circuit breaker.
[0070] Other details of the implementation of each unit in the evaluation device of the post-arc thermal interruption performance of the circuit breaker to achieve the above technical solutions can be referred to the description in the above-provided evaluation method of the post-arc thermal interruption performance of the circuit breaker, which will not be described here again.
[0071] In the embodiments of the present application, a computer device is provided, please refer to Figure 6 , Figure 6 is a structural schematic diagram of the computer device in an embodiment, the device includes a memory 301 and a processor 302, the memory 301 stores a computer program, and the computer program is executed by the processor 302, so that the processor 302 executes the following steps: constructing a multi-physics field coupled arc model of the circuit breaker, and developing arc simulation to obtain pre-zero arc current and arc voltage data, the multi-physics field includes temperature field, airflow field and electric field of the circuit breaker; based on the pre-zero arc current and arc voltage data, fitting the pre-zero arc time constant θ and the arc energy dissipation coefficient Q by using the Mayr model; based on the pre-zero arc time constant θ and the energy dissipation coefficient Q as parameters of the post-zero arc model, predicting the post-arc current value under different recovery voltage rise rates; determining the corresponding recovery voltage rise rate when the post-arc current value does not decrease to zero within a preset time as the critical recovery voltage rise rate; Determine the actual recovery voltage rise rate across the circuit breaker under the near-zone fault condition based on the circuit parameters of the preset near-zone fault condition; Compare the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker.
[0072] The processor 302 can also be called a CPU (Central Processing Unit). The processor 302 can be an integrated circuit chip including a processing unit that can process signals. The processor 302 can also be a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a FPGA (Field Programmable Gate Array), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof.
[0073] In the embodiments of the present application, a computer readable storage medium is provided. Please refer to Figure 7 , Figure 7 FIG. 1 is a structural schematic diagram of a computer readable storage medium according to an embodiment of the present application. The computer readable storage medium stores a computer program 401. The computer program 401 can be stored in the storage medium in the form of a software product, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server machine, or a network device, etc.) or a processor to perform the following steps: Construct a multi-physics field coupled arc model of the circuit breaker, and perform arc simulation to obtain pre-arc current and arc voltage data. The multi-physics field includes temperature field, airflow field, and electric field of the circuit breaker; Based on the pre-arc current and arc voltage data, a Mayr model is used to fit to obtain the pre-arc time constant θ and the arc energy dissipation coefficient Q; Based on the pre-arc time constant θ and the energy dissipation coefficient Q as parameters of the post-arc model, predict the post-arc current value under different recovery voltage rise rates; Determine the corresponding recovery voltage rise rate when the post-arc current value does not decrease to zero within a preset time as the critical recovery voltage rise rate; Determine the actual recovery voltage rise rate across the circuit breaker under the near-zone fault condition based on the circuit parameters of the preset near-zone fault condition; Compare the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker.
[0074] The storage medium described above includes a U disk, a mobile hard disk, a magnetic or optical disk, a ROM (Read-Only Memory), a RAM (Random Access Memory), and other various storage media that can store program codes, or a terminal device such as a computer, a service machine, a mobile phone, and a tablet.
[0075] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the program can be stored in a non-volatile computer readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiments. Any reference to memory, storage, database or other medium used in the embodiments provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
[0076] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.
[0077] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, some modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.
Claims
1. A method for evaluating the post-arc thermal interruption performance of a circuit breaker, characterized in that, include; A multiphysics coupled arc model of the circuit breaker is constructed, and arc simulation is carried out to obtain zero-preceding arc current and arc voltage data. The multiphysics includes the temperature field, airflow field and electric field of the circuit breaker. Based on the zero-preceding arc current and arc voltage data, the arc time constant θ and arc energy dissipation coefficient Q before zero were obtained by fitting the Mayr model. Based on the arc time constant θ and energy dissipation coefficient Q before zero as parameters of the arc model after zero, the post-arc current value is predicted under different recovery voltage rise rates. The rate of increase of recovery voltage when the post-arc current value does not drop to zero within a preset time is defined as the critical rate of increase of recovery voltage. Based on the preset circuit parameters for near-zone fault conditions, the actual recovery voltage rise rate across the circuit breaker under near-zone fault conditions is determined. The thermal interruption performance of the circuit breaker is evaluated by comparing the actual recovery voltage rise rate with the critical recovery voltage rise rate.
2. The method for evaluating the post-arc thermal interruption performance of a circuit breaker according to claim 1, characterized in that, The determination of the actual recovery voltage rise rate across the circuit breaker under near-zone fault conditions, based on preset circuit parameters, specifically includes: Determine the first peak-to-peak voltage of the line-side oscillation voltage; The overall recovery voltage rise time is determined based on the power supply side delay and the rise time of the line side to the first peak voltage. The total peak value of the recovery voltage across the circuit breaker is determined by summing the power supply side recovery voltage, the initial transient recovery voltage, and the line side recovery voltage. The actual recovery voltage rise rate across the circuit breaker is determined by the ratio of the peak value of the overall recovery voltage across the circuit breaker to the rise time of the overall recovery voltage.
3. The method for evaluating the post-arc thermal interruption performance of a circuit breaker according to claim 2, characterized in that, The first peak-to-peak voltage of the line-side oscillation voltage is determined according to the following formula: in, The rated voltage of the circuit breaker. For near-field fault interruption current, This is the rated short-circuit breaking current. Peak coefficient, This is the peak-to-peak voltage of the first wave of the line-side oscillation voltage.
4. The method for evaluating the post-arc thermal interruption performance of a circuit breaker according to claim 1, characterized in that, The Mayr model formula is: in, For arc conductivity, Arc voltage It is the arc current. The arc time constant, This is the arc energy dissipation coefficient.
5. The method for evaluating the post-arc thermal interruption performance of a circuit breaker according to claim 1, characterized in that, The comparison of the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker includes: By comparing the actual recovery voltage rise rate with the critical recovery voltage rise rate, the circuit breaker is assessed to determine whether thermal breakdown has occurred. If the actual recovery voltage rise rate is greater than or equal to the critical recovery voltage rise rate, thermal breakdown occurs and the circuit breaker fails to interrupt thermally. If the actual recovery voltage rise rate is less than the critical recovery voltage rise rate, the circuit breaker can successfully thermally interrupt the circuit.
6. The method for evaluating the post-arc thermal interruption performance of a circuit breaker according to claim 2, characterized in that, The overall recovery voltage rise time is determined using the following formula: in, Z is the rate of rise of the current at the zero crossing, and Z is the line impedance. For power supply side delay, The rise time for the line side to reach the first peak voltage. The overall recovery voltage rise time, This is the peak-to-peak voltage of the first wave of the line-side oscillation voltage.
7. The method for evaluating the post-arc thermal interruption performance of a circuit breaker according to claim 2, characterized in that, The peak value of the overall recovery voltage across the circuit breaker is determined using the following formula: in, The bus voltage drop under the initial transient recovery voltage. To restore the rate of voltage rise on the power supply side, For power supply side delay, The multiplier coefficient, Peak coefficient, The overall recovery voltage rise time, This is the first peak-to-peak voltage of the line-side oscillation voltage. This represents the peak value of the overall recovery voltage across the circuit breaker.
8. An evaluation device for the post-arc thermal interruption performance of a circuit breaker, characterized in that, The device includes; The simulation unit is used to construct a multi-physics coupled arc model of the circuit breaker and to carry out arc simulation to obtain zero-preceding arc current and arc voltage data. The multi-physics includes the temperature field, airflow field and electric field of the circuit breaker. The fitting unit is used to obtain the arc time constant θ and arc energy dissipation coefficient Q before zero based on the zero-preceding arc current and arc voltage data using the Mayr model. The prediction unit is used to predict the post-arc current value under different recovery voltage rise rates, based on the pre-zero arc time constant θ and energy dissipation coefficient Q as parameters of the post-zero arc model. The filtering unit is used to determine the rate of recovery voltage rise when the post-arc current value does not drop to zero within a preset time as the critical rate of recovery voltage rise. The determination unit, based on the circuit parameters of the preset near-zone fault condition, determines the actual recovery voltage rise rate across the circuit breaker under the near-zone fault condition. An evaluation unit is used to compare the actual recovery voltage rise rate with the critical recovery voltage rise rate to evaluate the thermal interruption performance of the circuit breaker.
9. A computer device, characterized in that, It includes a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, The device stores a computer program that, when executed by a processor, causes the processor to perform the steps of the method as described in any one of claims 1 to 7.