Section data output method and device for fault simulation of intelligent circuit breaker

Abstract

The invention discloses a section data output method and device for fault simulation of an intelligent circuit breaker. The method comprises the following steps: building a low-voltage power distribution system simulation model with various fault simulation functions; simulation of various types of conventional faults is carried out, short circuit, grounding, overvoltage and undervoltage fault voltage and current under different system grounding modes, different fault positions, different fault phases and different transition resistors are output, and a Comtrade wave recording file is generated according to a simulation result; performing different types of residual current fault simulation, outputting residual current containing different proportions of capacitive components and resistive components, and generating a Comtrade wave recording file according to a simulation result; simulation of various series arc faults of the low-voltage distribution line is carried out, series fault arc voltages and currents under different load characteristics are output, and a Comtrade wave recording file is generated according to simulation results; and according to a COMTRADE recording file generated according to the simulation result, outputting section data of fault simulation of the intelligent circuit breaker of each node in the low-voltage power distribution system. According to the fault simulation section data of the intelligent circuit breaker, comprehensive testing of various protection and fault detection functions of the intelligent circuit breaker can be realized.

Description

Technical Field

[0001] This invention belongs to the field of fault simulation technology for low-voltage power distribution systems, and relates to a method and device for outputting cross-sectional data, particularly a method and device for outputting cross-sectional data for simulating faults in intelligent circuit breakers. Background Technology

[0002] Intelligent circuit breakers are key equipment in low-voltage distribution networks. Common faults in low-voltage distribution lines include short circuits, grounding faults, leakage current, and arcing. Distribution lines have complex topologies, characterized by numerous points, long lines, and wide coverage. The principles and coordinated interlocking actions for fault detection, fault isolation, and power restoration differ across different types of distribution network systems. To ensure the correctness and reliability of the actions of various types of distribution network systems, an effective testing method is needed to comprehensively test the fault detection and protection functions of low-voltage circuit breakers for different types of faults. In the prior art, patent CN202110821684.1, "A Full-Element Panoramic Simulation Test Platform for Low-Voltage Distribution Network and Its Test Method," proposes a full-element panoramic simulation test platform for low-voltage distribution networks and its test method, which can shorten the test time, but its simulation capability for different faults and system structures is limited. Patent CN202411234704.5, "A Typical Fault Simulation Test Platform for Low-Voltage Distribution Network and Its Test Method," provides a typical fault simulation test platform for low-voltage distribution networks, which can realistically simulate the operating state of low-voltage distribution networks and reproduce various typical faults of low-voltage distribution networks, but its comprehensiveness, flexibility, and efficiency in fault simulation are lacking.

[0003] The protective operation performance and reliability of low-voltage intelligent circuit breakers are directly related to the power supply safety of low-voltage distribution substations. Traditional intelligent circuit breaker fault detection often only tests by applying fault signals such as overcurrent and overvoltage using a tester, but cannot systematically detect the sensitivity of current and voltage protection under different grounding methods, the impact of harmonic interference injected by distributed source loads on protection, the impact of different residual current generation mechanisms on residual current detection function, and the impact of series arc faults on arc protection function under different loads. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a method and apparatus for outputting cross-sectional data for simulating faults in intelligent circuit breakers, which can achieve comprehensive testing of various protection and fault detection functions of intelligent circuit breakers.

[0005] The above-mentioned objective of this invention is achieved through the following technical solution:

[0006] A method for outputting cross-sectional data for fault simulation of smart circuit breakers includes the following steps:

[0007] A simulation model of a low-voltage power distribution system with various fault simulation functions was built using simulation software.

[0008] Based on the established low-voltage power distribution system simulation model, simulations of different types of common faults such as short circuit, grounding, undervoltage, and overvoltage are conducted. These different types of faults need to be simulated separately under different system grounding methods, different fault locations, different fault phases, different transition resistances, and different occurrence times to evaluate the speed, reliability, selectivity, and sensitivity of the intelligent circuit breaker's protection against short circuit, grounding, undervoltage, and overvoltage.

[0009] Based on the simulation results of various types of common faults, a Comtrade waveform file is generated.

[0010] Based on the established low-voltage power distribution system simulation model, further simulations of different types of residual current faults are conducted, and residual currents containing capacitive and resistive components in different proportions are output.

[0011] Based on the simulation results of residual current faults, a Comtrade waveform file is generated;

[0012] Based on the established simulation model of the low-voltage power distribution system, various series arc faults of the low-voltage power distribution line are further simulated, and the series fault arc voltage and current under different load characteristics are output.

[0013] Based on the simulation results of series arc fault, a Comtrade waveform file is generated;

[0014] Comtrade waveform files generated from the simulations of conventional faults, residual current faults, and arc faults are combined to finally output cross-sectional data of fault simulation of smart circuit breakers at each node in the low-voltage power distribution system.

[0015] The low-voltage power distribution system simulation model includes simulation components such as power frequency power supply, harmonic power supply of different frequencies, line impedance, different types of loads, three-phase ground distributed capacitance and insulation resistance, and fault arc model, and can simulate different grounding methods such as IT / TT / TN.

[0016] Among them, the power frequency voltage source is used to simulate the output voltage of the distribution transformer and provide power frequency fault voltage and current for various faults; the harmonic power supply is used to simulate the generation of different frequency harmonics injected by distributed source and load; the three-phase ground distributed capacitance and insulation resistance are used to simulate different residual current generation mechanisms and to generate resistive and capacitive residual currents with different components; different types of loads, including resistive loads, inductive loads and capacitive loads, are used in conjunction with the fault arc model to simulate the generation of series arc fault currents under different load characteristics; at the same time, it can simulate the different characteristics of the same fault under different grounding methods such as IT / TT / TN, different fault locations, different transition resistances and different occurrence times. This simulation model comprehensively covers the needs and scenarios of intelligent circuit breaker fault simulation.

[0017] Furthermore, the different types of conventional faults include: single-phase ground fault, two-phase ground fault, two-phase short-circuit fault and three-phase short-circuit fault. The system grounding method, fault location, transition resistance and fault occurrence time can be changed to evaluate the speed, reliability, selectivity and sensitivity of the short-circuit, ground, undervoltage and overvoltage protection of the intelligent circuit breaker.

[0018] Furthermore, the specific method for generating Comtrade waveform files based on simulation results of various types of conventional faults is as follows:

[0019] After completing the simulation of each fault, the three-phase voltage and three-phase current data output from the simulation are exported to the MATLAB workspace via the ToWorkspace component (Simulink component name). The output data is then further generated into a Comtrade waveform file.

[0020] Furthermore, the specific method for further simulating different types of residual current faults based on the established low-voltage power distribution system simulation model, and outputting residual currents containing capacitive and resistive components in different proportions, is as follows:

[0021] On the constructed low-voltage power distribution system simulation model, different residual current generation mechanisms are simulated by changing the distributed capacitance C and the insulation resistance to ground R of the three phases. The parameters of the harmonic voltage source are changed to simulate different harmonic interference operating conditions. The residual current containing capacitive and resistive components in different proportions is output to evaluate the calculation accuracy and protection capability of the intelligent circuit breaker residual current protection for the full-wave RMS value and full-wave resistive RMS value of the residual current.

[0022] Furthermore, the specific method for generating Comtrade waveform files based on residual current fault simulation results is as follows:

[0023] After each residual current fault simulation is completed, the simulation output of three-phase voltage, three-phase current and total residual current data is output to the work area via the ToWorkspace component and further generated into a Comtrade waveform file.

[0024] Furthermore, based on the established low-voltage power distribution system simulation model, the specific method for further simulating various series arc faults in low-voltage power distribution lines and outputting the series fault arc voltage and current under different load characteristics is as follows:

[0025] Based on the constructed low-voltage power distribution system simulation model, the series arc fault simulation model proposed in this invention is applied to a certain phase in series. The improved Cassie model parameters or Mayr model parameters are selected, and the nature of the load is changed respectively. The series fault arc voltage and current under different load characteristics are output to evaluate the ability of the intelligent circuit breaker arc fault protection to identify the fault arc.

[0026] Furthermore, the specific method for generating Comtrade waveform files based on the simulation results of series arc faults is as follows:

[0027] After each series arc fault simulation is completed, the three-phase voltage and three-phase current data output from the simulation are output to the work area via the ToWorkspace component and further generated into a Comtrade waveform file.

[0028] Comtrade waveform files generated from the simulations of conventional faults, residual current faults, and arc faults are combined to finally output cross-sectional data of fault simulations of smart circuit breakers at each node in the low-voltage power distribution system. These data are then used to comprehensively test the fault detection capabilities of the smart circuit breakers through waveform playback.

[0029] A cross-sectional data output device for simulating faults in smart circuit breakers, comprising:

[0030] The low-voltage power distribution system simulation model building module uses simulation software to build a low-voltage power distribution system simulation model with various fault simulation functions.

[0031] The conventional fault simulation module, based on the established low-voltage power distribution system simulation model, simulates different types of conventional faults, including short circuits, grounding faults, undervoltage faults, and overvoltage faults. These different fault types further require simulation under different system grounding methods, fault locations, fault phases, transition resistances, and occurrence times. This is used to evaluate the speed, reliability, selectivity, and sensitivity of the intelligent circuit breaker's short-circuit, grounding, undervoltage, and overvoltage protection.

[0032] The module for generating waveform files from simulation results of common faults generates Comtrade waveform files based on simulation results of various types of common faults.

[0033] The residual current fault simulation module, based on the established low-voltage power distribution system simulation model, further simulates different types of residual current faults and outputs residual currents containing capacitive and resistive components in different proportions.

[0034] The residual current fault simulation result waveform file generation module generates Comtrade waveform files based on the residual current fault simulation results.

[0035] The series arc fault simulation module, based on the established low-voltage power distribution system simulation model, further simulates various series arc faults in low-voltage power distribution lines and outputs series fault arc voltage and current under different load characteristics.

[0036] The module for generating waveform files from simulation results of series arc faults generates Comtrade waveform files based on the simulation results of series arc faults.

[0037] The cross-sectional data generation module for intelligent circuit breaker fault simulation integrates the COMTRADE waveform files generated from the simulations of conventional faults, residual current faults, and arc faults, and finally outputs the cross-sectional data of intelligent circuit breaker fault simulation at each node in the low-voltage power distribution system.

[0038] The low-voltage power distribution system simulation model includes simulation components such as power frequency power supply, harmonic power supply of different frequencies, line impedance, different types of loads, three-phase ground distributed capacitance and insulation resistance, and fault arc model, and can simulate different grounding methods such as IT / TT / TN.

[0039] Among them, the power frequency voltage source is used to simulate the output voltage of the distribution transformer and provide power frequency fault voltage and current for various faults; the harmonic power supply is used to simulate the generation of different frequency harmonics injected by distributed source and load; the three-phase ground distributed capacitance and insulation resistance are used to simulate different residual current generation mechanisms and to generate resistive and capacitive residual currents with different components; different types of loads, including resistive loads, inductive loads and capacitive loads, are used in conjunction with the fault arc model to simulate the generation of series arc fault currents with different characteristics; at the same time, it simulates the different characteristics of the same fault under different grounding methods such as IT / TT / TN, different fault locations, different transition resistances and different occurrence times. This simulation model comprehensively covers the needs and scenarios of intelligent circuit breaker fault simulation.

[0040] A computer-readable storage medium having program instructions stored thereon, which, when executed by a processor, implement a method for outputting cross-sectional data for simulating faults in a smart circuit breaker.

[0041] The advantages and positive effects of this invention are as follows:

[0042] 1. This invention proposes a method and device for outputting cross-sectional data for intelligent circuit breaker fault simulation. Using Matlab / Simulink simulation tools, various grounding methods and fault conditions of low-voltage power distribution systems are uniformly modeled, and a primary-side low-voltage power distribution network close to the real system is constructed. Cross-sectional data of the intelligent circuit breaker is output through simulation, and a Comtrade waveform file is generated. This results in an effective, convenient, and low-cost method and device for outputting cross-sectional data for intelligent circuit breaker fault simulation.

[0043] 2. This invention uses Matlab / Simulink simulation modeling to simulate low-voltage power distribution systems with different grounding methods such as IT / TT / TN, and has the simulation cross-section data output function required for short circuit, grounding, overvoltage, and undervoltage protection function tests required by conventional intelligent circuit breakers.

[0044] 3. The simulation model of this invention has the function of parameter modeling for different distributed capacitance and insulation resistance to ground, and can generate residual current of RC mixture under different harmonic interference, which meets the output function of simulation cross-section data required for testing of intelligent circuit breakers with residual current protection function.

[0045] 4. The simulation model of this invention combines simulation modeling of series arc faults under different load characteristics, which can generate series fault arc current and voltage under different loads and different mathematical models, and meet the output function of simulation cross-section data required for testing of intelligent circuit breakers with fault arc protection function.

[0046] 5. The cross-sectional data generated by this invention adopts the Comtrade standard waveform file, which has good universality, is convenient for software reading and fault inversion based on the test instrument, and is conducive to promotion and application. Attached Figure Description

[0047] Figure 1 This is a Matlab / Simulink simulation model diagram of the low-voltage power distribution system of the present invention;

[0048] Figure 2 This is a schematic diagram of the grounding method of the low-voltage power distribution system of the present invention;

[0049] Figure 3 The figure shows the Cassie / Mayr arc fault simulation model based on Matlab / Simulink of this invention;

[0050] Figure 4 The simulation output waveforms of the three-phase total residual current and resistive residual current when phase A leakage occurs are shown in the present invention.

[0051] Figure 5 The image shows the arc current and voltage waveforms output from the simulation of the Cassie model and a purely resistive load according to the present invention.

[0052] Figure 6 The image shows the arc current and voltage waveforms output from the simulation of the Cassie model with a resistive-inductive load according to the present invention.

[0053] Figure 7 The waveforms of arc current and voltage output from the simulation of the Cassie model and resistive-capacitive load of this invention are shown.

[0054] Figure 8 This is a flowchart of the processing of the present invention. Detailed Implementation

[0055] The structure of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that these embodiments are descriptive and not limiting.

[0056] A method for outputting cross-sectional data for fault simulation of smart circuit breakers, such as Figure 8 As shown, it includes the following steps:

[0057] Step 1: Build a low-voltage power distribution system simulation model with various fault simulation functions using Matlab / Simulink;

[0058] The low-voltage power distribution system simulation model in step 1 includes simulation components such as power frequency power supply, harmonic power supply, line impedance, different types of loads, three-phase ground distributed capacitance and insulation resistance, and fault arc model, and can simulate different grounding methods such as IT / TT / TN.

[0059] Step 2: Based on the low-voltage power distribution system simulation model constructed in Step 1, perform simulations of different types of common faults;

[0060] The different types of conventional faults in step 2 include: single-phase ground fault, two-phase ground fault, two-phase short-circuit fault and three-phase short-circuit fault. The system grounding method, fault location, transition resistance and fault occurrence time can be changed to evaluate the speed, reliability, selectivity and sensitivity of the intelligent circuit breaker's protection against short circuit, ground, undervoltage and overvoltage.

[0061] Step 3: Based on the simulation results from Step 2, generate a Comtrade waveform file;

[0062] The specific method for step 3 is as follows:

[0063] After completing the simulation of each type of conventional fault described in step 2, the simulation output of three-phase voltage and three-phase current data is output to the work area via the ToWorkspace component and further generated into a Comtrade waveform file.

[0064] Step 4: Based on the low-voltage power distribution system simulation model constructed in Step 1, perform simulations of different types of residual current faults and output residual currents containing capacitive and resistive components in different proportions.

[0065] The specific method for step 4 is as follows:

[0066] In the low-voltage power distribution system simulation model constructed in step 1, different residual current generation mechanisms are simulated by changing the distributed capacitance C and the insulation resistance to ground R of the three phases. The parameters of the harmonic voltage source are changed to simulate different harmonic interference operating conditions. The residual current containing capacitive and resistive components in different proportions is output to evaluate the calculation accuracy and protection capability of the intelligent circuit breaker residual current protection for the full-wave RMS value and full-wave resistive RMS value of the residual current.

[0067] Step 5: Based on the simulation results in Step 4, generate a Comtrade waveform file;

[0068] The specific method for step 5 is as follows:

[0069] After each residual current fault simulation is completed, the simulation output of three-phase voltage, three-phase current and total residual current data is output to the work area via the ToWorkspace component and further generated into a Comtrade waveform file.

[0070] Figure 4 This invention provides simulated output waveform data for the total residual current and resistive residual current when a phase A leakage occurs under unbalanced three-phase distributed capacitance with voltage sources containing 3rd and 5th harmonics. It demonstrates that the simulation model proposed in this invention possesses the ability to simulate leakage faults and output cross-sectional data under different residual current generation mechanisms.

[0071] Step 6: Based on the low-voltage power distribution system simulation model constructed in Step 1, perform simulations of various series arc faults in the low-voltage power distribution line, and output the series fault arc voltage and current under different load characteristics.

[0072] The specific method for step 6 is as follows:

[0073] Based on the low-voltage power distribution system simulation model constructed in step 1, the series arc fault simulation model proposed in this invention is connected in series with a certain phase (e.g., phase A) on this model. The improved Cassie model parameters or Mayr model parameters are selected, and the nature of the load (pure resistive, RC, RC) is changed respectively. The series fault arc voltage and current under different load characteristics are output to evaluate the ability of the intelligent circuit breaker arc fault protection to identify the fault arc.

[0074] Step 7: Based on the simulation results from Step 6, generate a Comtrade waveform file;

[0075] The specific method for step 7 is as follows:

[0076] After each series arc fault simulation is completed, the three-phase voltage and three-phase current data output from the simulation are output to the work area via the ToWorkspace component and further generated into a Comtrade waveform file.

[0077] Figure 5 The simulation output includes arc current and voltage waveform data under the Cassie model and a purely resistive load.

[0078] Figure 6 The simulation output includes arc current and voltage waveform data under the Cassie model and resistive-inductive load.

[0079] Figure 7 This provides the arc current and voltage waveform data from the simulation output under the Cassie model and resistive-capacitive load.

[0080] As can be seen, the simulation model proposed in this invention has the functions of simulating series arc faults under different load characteristics and outputting cross-sectional data.

[0081] Step 8: Combining the COMTRADE waveform files generated from the simulations of conventional faults, residual current faults, and arc faults, the final output is the cross-sectional data of the fault simulation of the intelligent circuit breakers at each node in the low-voltage power distribution system.

[0082] The working principle of this invention is:

[0083] A method for outputting cross-sectional data for fault simulation of smart circuit breakers includes the following steps:

[0084] 1. The low-voltage power distribution system was modeled using a phase-by-phase modeling method. Each phase included components such as the power frequency voltage source, harmonic voltage source 1, harmonic voltage source 2, ..., harmonic voltage source N, line impedance, line distributed capacitance, load impedance, three-phase voltmeters at the location of the intelligent circuit breaker, three-phase ammeters, and residual ammeters, etc. Figure 1 As shown;

[0085] 2. The three-phase amplitude of the power frequency voltage source is set to 220V, the frequency is set to 50Hz, and the phases are 0°, 240°, and 120° respectively. The three-phase amplitude, frequency, and phase of harmonic voltage source 1, harmonic voltage source 2, ... harmonic voltage source N can be flexibly set according to the simulation needs to simulate different operating conditions of power frequency + harmonic interference superposition.

[0086] 3. The grounding method of the low-voltage power distribution system can be determined according to... Figure 2The schematic diagram simulates three typical grounding methods by controlling the opening and closing of three switches K1, K2, and K3. In the IT method: K1 is open, K2 is open, and K3 is closed; in the TT method: K1 is closed, K2 is closed, and K3 is open; in the TN method: K1 is closed, K2 is open, and K3 is closed.

[0087] 4. Line impedance can be simulated using RLC elements, typically with C set to 0F. The distributed capacitance of the line is simulated using independent RC parallel elements, where C represents the distributed capacitance and R represents the insulation resistance of the three-phase line. Different values ​​of the three-phase-to-ground distributed capacitance Ca, Cb, and Cc can simulate the unbalanced operating condition of the three-phase distributed capacitance, thus generating a capacitive component in the total residual current of the three-phase RCD (Residual Current Device, a type of intelligent circuit breaker). The three-phase-to-ground insulation resistance values ​​Ra, Rb, and Rc can be set to different values ​​as needed to simulate the failure of the insulation resistance of any phase line, thus generating a resistive component in the total residual current of the three-phase RCD.

[0088] 5. The line load is also simulated using RLC components. Depending on the simulation requirements, it can be set to R as a purely resistive load, RC as a resistive-capacitive load, or RL as a resistive-inductive load.

[0089] 6. A simulation method for series arc faults based on an improved Cassie / Mayr model is proposed to simulate series arc faults in low-voltage distribution lines. Depending on the simulation requirements, either the improved Cassie model or the improved Mayr model can be selected to simulate the arc fault. The basic principle of the Cassie / Mayr model is as follows:

[0090] In the Cassie arc model, the temperature across the arc cross-section is assumed to be uniformly distributed, and the boundary of the channel, i.e., its diameter, is relatively well-defined, with very high impedance outside the diameter. Assuming that the current magnitude in the generated arc is constantly changing, according to the Cassie model, the arc temperature is relatively stable in time and space, without significant variations. However, the boundary of the gas channel changes with the current magnitude, i.e., the channel diameter changes, leading to energy dissipation. In power frequency electricity, the arc voltage gradient remains essentially constant; therefore, under the Cassie model, the energy dissipation rate is directly proportional to the change in the arc column's cross-section.

[0091] The mathematical equations for the Cassie arc model are:

[0092]

[0093] In the formula:

[0094] g—Arc conductivity;

[0095] τ—Arc time constant;

[0096] u h —Instantaneous value of arc voltage gradient;

[0097] u c — Arc voltage constant.

[0098] The Mayr arc model assumes that the boundary of the arc gas channel, i.e., its diameter, is constant. Energy is lost through thermal conduction and radial diffusion. The Mayr arc model assumes that this energy loss is constant, while the arc temperature changes with the radial distance from the axis of the cylindrical channel and time. Therefore, the arc power dissipation under the Mayr arc model is constant.

[0099] The mathematical equations for the Mayr arc model are:

[0100]

[0101] In the formula:

[0102] P h —Arc input power;

[0103] P l —Power dissipated by electric arc.

[0104] 7. A system was built using Matlab / Simulink, such as... Figure 3 The Cassie / Mayr arc fault simulation model shown contains a mathematical model module that implements the differential equation solving algorithms for the two mathematical models mentioned above. This invention makes the following improvements to the initial values ​​and constants of the differential equation algorithm to avoid divergence that may occur during the simulation process.

[0105] Under the Cassie model, the power supply and model parameter settings are as follows:

[0106] Power supply voltage: peak 220V, frequency 50Hz, angle 90°

[0107] Model parameters: Uc = 130V, τ = 2.25e-4 seconds = 225µs, g(0) = 1.17e-4S = 0.000117S

[0108] In the Mayr model, the power supply and model parameter settings are as follows:

[0109] Power supply voltage: peak 10000V, frequency 60Hz, angle 90°

[0110] Model parameters: P0 = 30900W, τ = 9e-5 seconds = 9us, g(0) = 1e4S = 10000S

[0111] 8. The Scope (oscilloscope) element of Matlab / Simulink is used to simulate the ADC sampling element at the installation location of the smart circuit breaker. The simulation data is saved to a .mat format file by outputting to the ToWorkSpace element. Matlab reads the file and further generates a Comtrade standard waveform file, which can be used for fault simulation testing of the smart circuit breaker.

[0112] The innovation of this invention lies in:

[0113] This invention relates to a method for outputting cross-sectional data for circuit breaker fault simulation. Its core is a simulation model of a low-voltage power distribution system based on Matlab / Simulink. This model includes simulations of IT / TT / TN grounding methods, simulations of different harmonic sources, simulations of various types of conventional faults, simulations of capacitive residual current caused by distributed capacitance and resistive residual current caused by insulation failure, as well as combinations of both, and simulations of series arc faults under different load characteristics. All simulation output cross-sectional data can be generated into a Comtrade standard waveform file for use by various protection and fault detection functions of intelligent circuit breakers.

[0114] The method of the present invention includes, but is not limited to: simultaneously detecting multiple smart circuit breakers, simulating the output of each node in different low-voltage power distribution networks, and the triggering conditions between each node can be interconnected through the network to reproduce the real situation of the entire low-voltage power distribution system to a greater extent.

[0115] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for outputting cross-sectional data for fault simulation of intelligent circuit breakers, characterized in that: Includes the following steps: A simulation model of a low-voltage power distribution system with various fault simulation functions was built using simulation software. Based on the established simulation model of the low-voltage power distribution system, simulations of different types of common faults such as short circuit, grounding, low voltage, and overvoltage are performed. These different types of common faults need to be simulated separately under different system grounding methods, different fault locations, different fault phases, and different transition resistances. Based on the results of conventional fault simulation, a common format (Comtrade) waveform file for transient data exchange in power systems is generated. Based on the established low-voltage power distribution system simulation model, further simulations of different types of residual current faults are conducted, and residual currents containing capacitive and resistive components in different proportions are output. Based on the simulation results of residual current faults, a Comtrade waveform file is generated; Based on the established simulation model of the low-voltage power distribution system, various series arc faults of the low-voltage power distribution line are further simulated, and the series fault arc voltage and current under different load characteristics are output. Based on the simulation results of series arc fault, a Comtrade waveform file is generated; Comtrade waveform files generated from the simulations of conventional faults, residual current faults, and arc faults are combined to finally output cross-sectional data of fault simulation of smart circuit breakers at each node in the low-voltage power distribution system. The low-voltage power distribution system simulation model includes the following components: power frequency power supply, harmonic power supply of different frequencies, line impedance, different types of loads, three-phase ground distributed capacitance and insulation resistance, fault arc model and other simulation elements, and can simulate different grounding methods such as IT / TT / TN (IT - Isolation-Terra System; Terra-Terra System, TN - Terra-Neutral System); Among them, the power frequency voltage source is used to simulate the output voltage of the distribution transformer and provide power frequency fault voltage and current for various faults; the harmonic power supply is used to simulate the generation of different frequency harmonics by distributed source-load injection; the three-phase ground distributed capacitance and insulation resistance are used to simulate different residual current generation mechanisms and to generate resistive and capacitive residual currents with different components; different types of loads, including resistive loads, inductive loads and capacitive loads, are used in conjunction with the fault arc model to simulate the generation of series arc fault currents under different load characteristics; at the same time, it can simulate the different characteristics of the same fault under different grounding methods such as IT / TT / TN, different fault locations, different transition resistances and different occurrence times. This simulation model comprehensively covers the needs and scenarios of intelligent circuit breaker fault simulation.

2. The method for outputting cross-sectional data for fault simulation of intelligent circuit breakers according to claim 1, characterized in that: The different types of conventional faults include: single-phase ground fault, two-phase ground fault, two-phase short-circuit fault and three-phase short-circuit fault. These different types of faults need to be simulated separately under different system grounding methods, different fault locations, different fault phases, different transition resistances and different occurrence times to evaluate the speed, reliability, selectivity and sensitivity of the intelligent circuit breaker's protection against short circuits, grounding, undervoltage and overvoltage.

3. The method for outputting cross-sectional data for fault simulation of intelligent circuit breakers according to claim 1, characterized in that: The specific method for generating Comtrade waveform files of power systems based on simulation results of various types of conventional faults is as follows: After completing the simulation of each fault, the three-phase voltage and three-phase current data output from the simulation are exported to the MATLAB workspace via the ToWorkspace component. The data is then output to the workspace and further generated into a Comtrade waveform file.

4. The method for outputting cross-sectional data for fault simulation of intelligent circuit breakers according to claim 1, characterized in that: The specific method for further simulating different types of residual current faults based on the established low-voltage power distribution system simulation model, and outputting residual currents containing capacitive and resistive components in different proportions, is as follows: On the constructed low-voltage power distribution system simulation model, different residual current generation mechanisms are simulated by changing the distributed capacitance C and the insulation resistance to ground R of the three phases. The parameters of the harmonic voltage source are changed to simulate different harmonic interference operating conditions, and the residual current containing capacitive and resistive components in different proportions is output.

5. The method for outputting cross-sectional data for fault simulation of intelligent circuit breakers according to claim 1, characterized in that: The specific method for generating Comtrade waveform files based on residual current fault simulation results is as follows: After each residual current fault simulation is completed, the simulation output of three-phase voltage, three-phase current and total residual current data is output to the work area via the ToWorkspace component and further generated into a Comtrade waveform file.

6. The method for outputting cross-sectional data for fault simulation of intelligent circuit breakers according to claim 1, characterized in that: The specific method for further simulating various series arc faults in low-voltage distribution lines based on the established low-voltage power distribution system simulation model, and outputting series fault arc voltage and current under different load characteristics, is as follows: Based on the constructed low-voltage power distribution system simulation model, the series arc fault simulation model proposed in this invention is applied to a certain phase in series. The improved Cassie model parameters or Mayr model parameters are selected, and the nature of the load is changed respectively to output the series fault arc voltage and current under different load characteristics.

7. The method for outputting cross-sectional data for fault simulation of intelligent circuit breakers according to claim 1, characterized in that: The specific method for generating Comtrade waveform files based on the simulation results of series arc faults is as follows: After each series arc fault simulation is completed, the simulation output of three-phase voltage and three-phase current data is output to the work area via the ToWorkspace component and further generated into a Comtrade waveform file. Comtrade waveform files generated from the simulations of conventional faults, residual current faults, and arc faults are combined to finally output cross-sectional data of fault simulations of smart circuit breakers at each node in the low-voltage power distribution system. These data are then used to comprehensively test the fault detection capabilities of the smart circuit breakers through waveform playback.

8. A cross-sectional data output device for simulating faults in intelligent circuit breakers, characterized in that: include: The low-voltage power distribution system simulation model building module uses simulation software to build a low-voltage power distribution system simulation model with various fault simulation functions. The conventional fault simulation module, based on the established low-voltage power distribution system simulation model, simulates different types of conventional faults such as short circuit, grounding, low voltage, and overvoltage. These different types of faults need to be simulated separately under different system grounding methods, different fault locations, different fault phases, different transition resistances, and different occurrence times. The module for generating waveform files from simulation results of common faults generates Comtrade waveform files based on simulation results of various types of common faults. The residual current fault simulation module, based on the established low-voltage power distribution system simulation model, further simulates different types of residual current faults and outputs residual currents containing capacitive and resistive components in different proportions. The residual current fault simulation result waveform file generation module generates Comtrade waveform files based on the residual current fault simulation results. The series arc fault simulation module, based on the established low-voltage power distribution system simulation model, further simulates the series arc fault of low-voltage power distribution lines and outputs the series fault arc voltage and current under different load characteristics. The module for generating waveform files from simulation results of series arc faults generates Comtrade waveform files based on the simulation results of series arc faults. The cross-sectional data generation module for intelligent circuit breaker fault simulation integrates the COMTRADE waveform files generated from the simulations of conventional faults, residual current faults, and arc faults, and finally outputs the data for each node in the low-voltage power distribution system. The low-voltage power distribution system simulation model includes: power frequency power supply, harmonic power supply of different frequencies, line impedance, different types of loads, three-phase ground distributed capacitance and insulation resistance, fault arc model and other simulation components, and can simulate different grounding methods such as IT / TT / TN. Among them, the power frequency voltage source is used to simulate the output voltage of the distribution transformer and provide power frequency fault voltage and current for various faults; the harmonic power supply is used to simulate the generation of different frequency harmonics injected by distributed source and load; the three-phase ground distributed capacitance and insulation resistance are used to simulate different residual current generation mechanisms and to generate resistive and capacitive residual currents with different components; different types of loads, including resistive loads, inductive loads and capacitive loads, are used in conjunction with the fault arc model to simulate the generation of series arc fault currents with different characteristics; at the same time, it simulates the different characteristics of the same fault under different grounding methods such as IT / TT / TN, different fault locations, different transition resistances and different occurrence times. This simulation model comprehensively covers the needs and scenarios of intelligent circuit breaker fault simulation.

9. A computer-readable storage medium having stored thereon program instructions that, when executed by a processor, implement a method for outputting cross-sectional data for simulating faults in a smart circuit breaker as described in any one of claims 1 to 7.

Images