Ground fault arc flash level analysis method and device

Abstract

The invention provides a ground fault arc flash level analysis method and device which can be used in the technical field of electronic power, and the method comprises the steps: determining a symmetric current signal and an asymmetric current signal from an obtained ground fault current; generating a current value of the asymmetric current signal according to the current value of the symmetric current signal and the obtained reactance-resistance ratio; an arc flash level is analyzed using the current value of the asymmetric current signal and the current value of the symmetric current signal. According to the ground fault arc flash level analysis method and device provided by the invention, the stability and safety of a power system in different grounding modes are ensured, and the fault processing accuracy is improved.

Description

Technical Field

[0001] The present application relates to the technical field of relay protection for electric power systems, and in particular to a method and device for analyzing arc flash levels of ground faults. Background Art

[0002] An arc flash is a dangerous or even deadly event that can occur during a short circuit. The temperature can reach up to four times the temperature of the sun's surface and produce an explosive pressure wave that can reach speeds of more than 1,000 kilometers per hour. Arc flashes can be caused by a variety of factors, including accidental contact with conductors, component failure, lack of maintenance, cable corrosion, and aging of equipment or components. The level of hazard from an arc flash depends primarily on the energy of the event, which is usually measured in calories per square centimeter (cal / cm 2 ) is measured in units of . The energy of an accident is affected by several factors, the most important of which include the fault clearing time, the magnitude of the ground fault current and the system voltage.

[0003] Statistics show that about 95% of industrial equipment short circuit accidents are triggered by ground faults. The ground fault current level is crucial in arc flash calculations because the higher the current value, the greater the energy level of the arc flash. Therefore, choosing a suitable grounding method is of great significance to reducing the accident energy during a ground fault.

[0004] To solve the problems existing in ungrounded systems, grounded neutral technology came into being. IEEE Std.242-2001 specifies four commonly used system grounding methods in industrial and commercial power systems: solid grounding, high resistance grounding (HRG), low resistance grounding (LRG) and ungrounded systems. Among these methods, the correct selection and application of grounded neutral can significantly affect the level of accident energy.

[0005] However, in the calculation of arc flash energy, if there is an error, it will be difficult to demonstrate an effective energy reduction method. The IEEE 1584-2018 standard only discusses the use of symmetrical RMS (Root Mean Square) current values ​​to estimate arc flash, but the accuracy and reliability of this estimation method needs to be improved. Summary of the invention

[0006] In view of the problems in the prior art, the embodiments of the present application provide a method and device for analyzing the arc flash level of a ground fault, which can at least partially solve the problems in the prior art.

[0007] In a first aspect, the present application provides a ground fault arc flash level analysis method, comprising:

[0008] determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current;

[0009] generating a current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio;

[0010] The arc flash level is analyzed using the current value of the asymmetric current signal and the current value of the symmetric current signal.

[0011] Further, determining the symmetrical current signal and the asymmetrical current signal from the acquired ground fault current includes:

[0012] identifying different current states from the ground fault current;

[0013] The symmetrical current signal and the asymmetrical current signal are identified according to different current states.

[0014] Further, the generating the current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio includes:

[0015] Determining a corresponding asymmetry factor according to the reactance-resistance ratio;

[0016] The current value of the asymmetric current signal is calculated using the asymmetry factor and the current value of the symmetric current signal.

[0017] Further, the analyzing the arc flash level by using the current value of the asymmetric current signal and the current value of the symmetric current signal includes:

[0018] Calculating respectively using the current value of the asymmetric current signal and the current value of the symmetric current signal to obtain the corresponding incident energy of the arc flash;

[0019] The different incident energies were compared and the arc flash levels were analyzed.

[0020] Furthermore, it also includes:

[0021] The corresponding ground fault current is simulated according to different grounding methods to analyze the arc flash level.

[0022] In a second aspect, the present application provides a ground fault arc flash level analysis device, comprising:

[0023] A current determination unit, used for determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current;

[0024] a current value generating unit, configured to generate a current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio;

[0025] The arc flash analysis unit is used to analyze the arc flash level by using the current value of the asymmetric current signal and the current value of the symmetric current signal.

[0026] Furthermore, the current determination unit includes:

[0027] A current state identification module, used for identifying different current states from the ground fault current;

[0028] The current determination module is used to identify the symmetrical current signal and the asymmetrical current signal according to different current states.

[0029] Furthermore, the current value generating unit includes:

[0030] A factor determination module, used to determine a corresponding asymmetry factor according to the reactance-resistance ratio;

[0031] The current value calculation module is used to calculate the current value of the asymmetric current signal by using the asymmetry factor and the current value of the symmetric current signal.

[0032] Further, the arc flash analysis unit comprises:

[0033] An incident energy calculation module, used to calculate the current value of the asymmetric current signal and the current value of the symmetric current signal respectively to obtain the corresponding incident energy of the arc flash;

[0034] The arc flash analysis module is used to compare the different incident energies and analyze the arc flash level.

[0035] Furthermore, it also includes:

[0036] The simulation unit is used to simulate the corresponding ground fault current according to different grounding modes to analyze the arc flash level.

[0037] In a third aspect, the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any one of the above embodiments when executing the computer program.

[0038] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described in any of the above embodiments is implemented.

[0039] In a fifth aspect, the present application provides a computer program product, wherein the computer program product includes a computer program, and when the computer program is executed by a processor, the method described in any of the above embodiments is implemented.

[0040] The ground fault arc flash level analysis method and device provided in the present application, by determining the symmetrical current signal and the asymmetrical current signal from the acquired ground fault current; generating the current value of the asymmetrical current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; analyzing the arc flash level using the current value of the asymmetrical current signal and the current value of the symmetrical current signal, achieves the goal of ensuring the stability and safety of the power system under different grounding modes and improving the accuracy of fault handling. Among them, by using the current value of the asymmetrical current signal and the current value of the symmetrical current signal to analyze the arc flash level, the accuracy of arc energy analysis during the ground fault can be significantly improved; by using high resistance grounding (HRG), the risk of accidents can be further reduced, the incident energy of the arc flash is effectively reduced, and the safety and reliability of the power system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a flow chart of a ground fault arc flash level analysis method provided by an embodiment of the present application;

[0043] Figure 2 It is a flow chart of a ground fault arc flash level analysis method provided by an embodiment of the present application;

[0044] Figure 3 It is a flow chart of a ground fault arc flash level analysis method provided by an embodiment of the present application;

[0045] Figure 4 It is a flow chart of a ground fault arc flash level analysis method provided by an embodiment of the present application;

[0046] Figure 5 It is a structural schematic diagram of a ground fault arc flash level analysis device provided by an embodiment of the present application;

[0047] Figure 6 It is a structural schematic diagram of a ground fault arc flash level analysis device provided by an embodiment of the present application;

[0048] Figure 7 It is a structural schematic diagram of a ground fault arc flash level analysis device provided by an embodiment of the present application;

[0049] Figure 8It is a structural schematic diagram of a ground fault arc flash level analysis device provided by an embodiment of the present application;

[0050] Fig. 9 It is a structural schematic diagram of a ground fault arc flash level analysis device provided by an embodiment of the present application;

[0051] Fig.10 is a schematic diagram of the physical structure of an electronic device provided in one embodiment of the present application;

[0052] Fig.11 is a waveform diagram of an asymmetric current provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not intended to limit the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

[0054] The following uses a server as an example of an execution subject to illustrate the specific implementation process of the ground fault arc flash level analysis method provided in the embodiment of the present application.

[0055] Figure 1 FIG. 1 is a flow chart of a method for analyzing ground fault arc flash level provided by an embodiment of the present application. Figure 1 As shown, the ground fault arc flash level analysis method provided by the present application includes:

[0056] S101: determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current;

[0057] S102: generating a current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio;

[0058] S103: Analyze the arc flash level using the current value of the asymmetric current signal and the current value of the symmetric current signal.

[0059] from Figure 1It can be seen from the process shown that the ground fault arc flash level analysis method and device provided in the present application, by determining the symmetrical current signal and the asymmetrical current signal from the acquired ground fault current; generating the current value of the asymmetrical current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; and analyzing the arc flash level using the current value of the asymmetrical current signal and the current value of the symmetrical current signal, achieves the goal of ensuring the stability and safety of the power system under different grounding methods and improving the accuracy of fault handling.

[0060] Each step is explained in detail below.

[0061] S101: determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current;

[0062] Specifically, in a short circuit fault, the current goes through different phases. In order to analyze the arc flash level of the ground fault, the server obtains the ground fault current and determines the symmetrical current and the asymmetrical current therefrom, the symmetrical current and the asymmetrical current being determined according to the different phases of the ground fault current.

[0063] Figure 2 FIG. 1 is a flow chart of a method for analyzing ground fault arc flash level provided by an embodiment of the present application. Figure 2 As shown, S101 includes:

[0064] S201: identifying different current states from the ground fault current;

[0065] Specifically, the server identifies the ground fault current and finds that in the first half cycle of the current wave, the short-circuit current reaches its maximum value, and this stage is the ultra-transient state of the fault. Subsequently, the ground fault current enters a transition state and gradually stabilizes within a certain period. Finally, the current enters a steady state, reaches a minimum value, and maintains this state until the fault is cleared. The server identifies the ultra-transient state, transition state, and steady state from the ground fault current to determine the symmetrical current and the asymmetrical current.

[0066] S202: Identify the symmetrical current signal and the asymmetrical current signal according to different current states.

[0067] Specifically, the server identifies the ground fault current and finds that in the super transient and transient state of the short-circuit current, the current waveform will be asymmetric, resulting in the generation of a DC component. This phenomenon is called asymmetric current, and its waveform is as follows: Fig.11 As shown, the short-circuit current is asymmetrical in the ultra-transient and transient states, and symmetrical in the steady state.

[0068] S102: generating a current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio;

[0069] Specifically, the magnitude and duration of the asymmetric current depend on two main factors: the phase angle of the voltage when the fault occurs and the system's reactance-resistance (X / R) ratio. The phase angle of the voltage determines the magnitude of the asymmetric current. If the phase angle is close to or equal to zero, the magnitude of the asymmetric current is large; conversely, a larger phase angle reduces the magnitude of the asymmetric current. The server calculates the current value (asymmetric component) of the asymmetric current based on the symmetrical current and the system's reactance-resistance (X / R) ratio.

[0070] Figure 3 FIG. 1 is a flow chart of a method for analyzing ground fault arc flash level provided by an embodiment of the present application. Figure 3 As shown, S102 includes:

[0071] S301: Determine a corresponding asymmetry factor according to the reactance-resistance ratio;

[0072] Specifically, the X / R ratio is positively correlated with the duration of the asymmetric current. In other words, the higher the X / R ratio, the longer it takes for the system current to gradually transition from the asymmetric state at the beginning of the fault to the steady state. Since the system's reactance-resistance ratio directly affects the speed of change of the current waveform, a higher X / R ratio will cause the current to exhibit more obvious attenuation characteristics at the beginning of the short circuit, extending the duration of the asymmetric current.

[0073] In order to accurately calculate the magnitude of the asymmetric current, an asymmetry factor is required. The asymmetry factor is a key parameter used to quantify the degree of current asymmetry in a system, and it varies according to the X / R ratio of the system. The higher the X / R ratio, the larger the asymmetry factor, which means that the initial peak value of the asymmetric current will increase accordingly, which will have a significant impact on the short-circuit current characteristics of the entire system.

[0074] When the server performs arc flash calculations, it first determines the corresponding asymmetry factor based on the X / R ratio of the power system. By combining the X / R ratio with the asymmetry factor, the server can accurately calculate the initial asymmetric component of the short-circuit current and further evaluate the energy level that may be generated during the arc flash process based on this value. The above method ensures the accuracy of the calculation results, especially when dealing with current fluctuations in the early stage of short-circuit faults, which can be effectively captured.

[0075] In one embodiment, the relationship between the X / R ratio and the asymmetry factor is shown in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] S302: Calculate the current value of the asymmetric current signal using the asymmetry factor and the current value of the symmetric current signal.

[0080] Specifically, after the server determines the corresponding asymmetry factor based on the system's reactance-resistance (X / R) ratio, it multiplies the symmetrical current by the asymmetry factor corresponding to the system's X / R ratio to calculate the asymmetric current component under short-circuit conditions. Among them, the asymmetry factor is a key parameter that reflects the degree of current asymmetry in the system, and it varies according to the X / R ratio. The asymmetric current component is the offset of the symmetrical current and contains the DC component caused by the voltage phase angle or other system characteristics at the initial stage of the fault. By considering the asymmetry factor, the server can more accurately reflect the true waveform of the current under short-circuit fault conditions.

[0081] S103: Analyze the arc flash level using the current value of the asymmetric current signal and the current value of the symmetric current signal.

[0082] Specifically, arc flash refers to the phenomenon that when an electrical fault occurs, an arc radiates heat energy in the form of radiation, convection, and conduction. The incident energy of an arc flash is measured in J / cm 2 or cal / cm 2 The arc flash incident energy level is affected by many factors, including short-circuit symmetrical current and fault clearing time. The operating voltage level of the power grid, the configuration and separation distance of the electrodes, the working distance, and the size of the equipment cabinet also affect the arc flash incident energy level. The server uses the current value of the asymmetrical current and the current value of the symmetrical current to analyze the arc flash level.

[0083] Figure 4 FIG. 1 is a flow chart of a method for analyzing ground fault arc flash level provided by an embodiment of the present application. Figure 4 As shown, S103 includes:

[0084] S401: Calculating the current value of the asymmetric current signal and the current value of the symmetric current signal to obtain the corresponding incident energy of the arc flash;

[0085] Specifically, the server calculates the incident energy of the arc flash using the ground fault current (the current value of the symmetrical current or the current value of the asymmetrical current), first calculates the arc current based on the ground fault current, then determines the arc duration based on the clearing time, and finally calculates the incident energy of the arc flash based on the arc current and the arc duration.

[0086] In one embodiment, the arc current I is calculated based on the ground fault current arc The expression is:

[0087]

[0088] In the formula, I f represents the ground fault current, V represents the nominal voltage of the system, and K1 and K2 are empirical coefficients.

[0089] In one embodiment, the incident energy E of the arc flash is calculated based on the arc current and the arc duration. arc The expression is:

[0090]

[0091] In the formula, I arc represents the arc current, t arc represents the arc duration, D is the distance from the arc to the working position, x is an empirical value, and K is a constant.

[0092] In one embodiment, the incident energy calculated using the symmetrical current is shown in Table 2.

[0093] Table 2

[0094]

[0095] In one embodiment, the incident energy calculated using the asymmetric current obtained according to different X / R ratios is shown in Table 3.

[0096] Table 3

[0097]

[0098] S402: Compare the different incident energies to analyze arc flash levels.

[0099] Specifically, the results of the server calculating the incident energy using the current value of the symmetrical current show that the incident energy level fluctuates significantly with the change of the short-circuit current size and the fault clearing time. Although the IEEE 1584 standard recommends the use of symmetrical current when calculating the incident energy, in actual situations, the symmetrical current may not be sufficient to accurately reflect the actual energy release level during the arc flash process. This is because in the early stage of the fault, the asymmetrical current will appear in the first few cycles, and its amplitude and duration will be affected by the system's reactance to resistance (X / R) ratio.

[0100] In this case, the amplitude of the asymmetric current is sometimes significantly higher than the symmetrical current, and because its impact is not fully considered in the traditional symmetrical current calculation, the calculated result of the incident energy may underestimate the actual risk. Therefore, when the server performs arc flash energy assessment, it comprehensively considers the system's X / R ratio and introduces the impact of asymmetric current. By using asymmetric current for incident energy calculation, the server is able to more accurately predict the energy level of the arc flash, thereby improving the accuracy of risk assessment and the effectiveness of safety protection. This method provides more reliable data support for safety designs related to arc flash, ensures that energy calculations are more in line with actual operating conditions, and reduces the errors that may be caused by traditional calculation methods.

[0101] In one embodiment, the arc current value of the busbar is relatively high, but the incident energy is relatively low due to its extremely short clearing time.

[0102] In one embodiment, there is a significant difference between the calculation results in Table 3 and Table 2. When the X / R ratio is determined, the incident energy calculated based on the asymmetric current is higher than the incident energy calculated based on the symmetric current. As the X / R ratio increases, the incident energy level also increases. Therefore, the asymmetric current and the X / R ratio of the system have a significant impact on the incident energy level of the arc flash.

[0103] In one embodiment, the ground fault arc flash level analysis method further includes:

[0104] The corresponding ground fault current is simulated according to different grounding methods to analyze the arc flash level.

[0105] Specifically, ungrounded systems offer significant advantages in dealing with arc flash, especially in the event of a ground fault, where the short-circuit current is very low due to the lack of a zero-sequence path, typically only manifesting as a charging current in the system. However, ungrounded systems are susceptible to damage to equipment during steady-state and transient overvoltages, so grounding methods are often used in modern power systems to increase reliability.

[0106] In a solid grounding system, the neutral point of the system is directly grounded, so no overvoltage will occur during a ground fault. Since the neutral point always remains at ground potential, the risk of neutral shift is avoided. However, solid grounding systems also have their disadvantages, mainly in the form of higher ground fault currents. Due to the low zero-sequence impedance of the system, the ground fault current is often greater than the positive and negative sequence fault currents, increasing the risk of arc faults. Especially in low-voltage systems of 480V and 600V, ground faults may escalate to phase-to-phase or three-phase arc faults, posing a threat to the stability and safety of the system.

[0107] The high resistance grounding system limits the ground fault current by connecting a high impedance resistor between the neutral point and the ground. This method effectively reduces the probability of overvoltage while allowing the system to continue to operate during the ground fault. Although a certain overvoltage may occur in the healthy phase, especially in systems above 5kV, this overvoltage will not develop into a serious fault. Therefore, the high resistance grounding (HRG) system is not recommended for use in systems above 5kV. In addition, the high resistance grounding (HRG) system also needs to be installed with a fault detection system so that the operator can quickly locate the fault and repair it.

[0108] The server simulated the ground fault current according to different grounding methods and found that the use of high resistance grounding (HRG) can significantly reduce the incident energy because the ground fault current is limited to a few amperes by the resistance. Under ground fault conditions, the arc flash phenomenon is easier to suppress due to the low short-circuit current. Therefore, the application of HRG technology significantly improves the reliability and safety of the system.

[0109] In one embodiment, the server performs a short circuit analysis based on the IEEE 242 system, and uses simulation software to simulate the changes in fault current and voltage. The analysis results show that in a solid grounding system, the ground fault current increases significantly, especially on the busbars closer to the power source. In the HRG system, the ground fault current is limited to about 10A, but the overvoltage of the healthy phase reaches 173% of the line-to-neutral voltage. This result demonstrates the advantages of the HRG system in limiting fault current, but also emphasizes its limitations in high-voltage applications.

[0110] The present application provides a method for analyzing arc flash level of ground fault, by determining symmetrical current signal and asymmetrical current signal from the acquired ground fault current; generating the current value of the asymmetrical current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; analyzing arc flash level by using the current value of the asymmetrical current signal and the current value of the symmetrical current signal, thereby ensuring the stability and safety of the power system under different grounding modes and improving the accuracy of fault handling. Among them, by analyzing arc flash level by using the current value of the asymmetrical current signal and the current value of the symmetrical current signal, the accuracy of arc energy analysis during ground fault can be significantly improved; by using high resistance grounding (HRG), the risk of accidents can be further reduced, the incident energy of arc flash can be effectively reduced, and the safety and reliability of the power system can be improved.

[0111] Based on the same inventive concept, the embodiment of the present application also provides a ground fault arc flash level analysis device, which can be used to implement the method described in the above embodiment, as described in the following embodiment. Since the principle of solving the problem by the ground fault arc flash level analysis device is similar to that of the ground fault arc flash level analysis method, the implementation of the ground fault arc flash level analysis device can refer to the implementation of the method based on software performance benchmark determination, and the repeated parts will not be repeated. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiment is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0112] Figure 5 is a schematic diagram of the structure of a ground fault arc flash level analysis device provided by an embodiment of the present application, such as Figure 5 As shown, the device comprises:

[0113] A current determination unit 501, configured to determine a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current;

[0114] Specifically, in a short circuit fault, the current goes through different stages. In order to analyze the arc flash level of the ground fault, the current determination unit 501 obtains the ground fault current and determines the symmetrical current and the asymmetrical current therefrom, wherein the symmetrical current and the asymmetrical current are determined according to the different stages of the ground fault current.

[0115] A current value generating unit 502, configured to generate a current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio;

[0116] Specifically, the amplitude and duration of the asymmetric current depend on two main factors: the phase angle of the voltage when the fault occurs and the ratio of the reactance resistance (X / R) of the system. The phase angle of the voltage determines the amplitude of the asymmetric current. If the phase angle is close to or equal to zero, the amplitude of the asymmetric current is large; on the contrary, a larger phase angle will reduce the amplitude of the asymmetric current. The current value generating unit 502 calculates the current value (asymmetric component) of the asymmetric current according to the symmetric current and the ratio of the reactance resistance (X / R) of the system.

[0117] The arc flash analysis unit 503 is used to analyze the arc flash level by using the current value of the asymmetric current signal and the current value of the symmetric current signal.

[0118] Specifically, arc flash refers to the phenomenon that when an electrical fault occurs, an arc radiates heat energy in the form of radiation, convection, and conduction. The incident energy of an arc flash is measured in J / cm 2 or cal / cm 2The arc flash analysis unit 503 analyzes the arc flash level using the current value of the asymmetrical current and the current value of the symmetrical current.

[0119] Figure 6 is a schematic diagram of the structure of a ground fault arc flash level analysis device provided by an embodiment of the present application. Figure 5 Based on the embodiment, further, Figure 6 As shown, the ground fault arc flash level analysis device provided by the present application also includes:

[0120] A current state identification module 601, used to identify different current states from the ground fault current;

[0121] The current determination module 602 is used to identify the symmetrical current signal and the asymmetrical current signal according to different current states.

[0122] Figure 7 is a schematic diagram of the structure of a ground fault arc flash level analysis device provided by an embodiment of the present application. Figure 5 Based on the embodiment, further, Figure 7 As shown, the ground fault arc flash level analysis device provided by the present application also includes:

[0123] A factor determination module 701, configured to determine a corresponding asymmetry factor according to the reactance-resistance ratio;

[0124] The current value calculation module 702 is used to calculate the current value of the asymmetric current signal by using the asymmetry factor and the current value of the symmetric current signal.

[0125] Figure 8 is a schematic diagram of the structure of a ground fault arc flash level analysis device provided by an embodiment of the present application. Figure 5 Based on the embodiment, further, Figure 8 As shown, the ground fault arc flash level analysis device provided by the present application also includes:

[0126] An incident energy calculation module 801, configured to calculate the current value of the asymmetric current signal and the current value of the symmetric current signal to obtain the corresponding incident energy of the arc flash;

[0127] The arc flash analysis module 802 is used to compare the different incident energies and analyze the arc flash level.

[0128] Fig. 9is a schematic diagram of the structure of a ground fault arc flash level analysis device provided by an embodiment of the present application. Figure 5 Based on the embodiment, further, Fig. 9 As shown, the ground fault arc flash level analysis device provided by the present application also includes:

[0129] The simulation unit 901 is used to simulate the corresponding ground fault current according to different grounding modes to analyze the arc flash level.

[0130] The present application provides a method and device for analyzing the arc flash level of a ground fault, which determines a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current; generates the current value of the asymmetrical current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; and analyzes the arc flash level using the current value of the asymmetrical current signal and the current value of the symmetrical current signal, thereby ensuring the stability and safety of the power system under different grounding modes and improving the accuracy of fault handling. Among them, by analyzing the arc flash level using the current value of the asymmetrical current signal and the current value of the symmetrical current signal, the accuracy of arc energy analysis during a ground fault can be significantly improved; by using high resistance grounding (HRG), the risk of accidents can be further reduced, the incident energy of the arc flash can be effectively reduced, and the safety and reliability of the power system can be improved.

[0131] Fig.10 is a schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application, such as Fig.10 As shown, the electronic device may include: a processor 1001, a communication interface 1002, a memory 1003 and a communication bus 1004, wherein the processor 1001, the communication interface 1002 and the memory 1003 communicate with each other through the communication bus 1004. The processor 1001 may call the logic instructions in the memory 1003 to execute the following method: determine a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current; generate a current value of the asymmetrical current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; and analyze the arc flash level using the current value of the asymmetrical current signal and the current value of the symmetrical current signal.

[0132] In addition, the logic instructions in the above-mentioned memory 1003 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk.

[0133] The present embodiment discloses a computer program product, which includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the methods provided by the above-mentioned method embodiments, for example, including: determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current; generating a current value of the asymmetrical current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; and analyzing an arc flash level using the current value of the asymmetrical current signal and the current value of the symmetrical current signal.

[0134] The present embodiment provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program enables the computer to execute the methods provided by the above-mentioned method embodiments, for example, including: determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current; generating a current value of the asymmetrical current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; and analyzing an arc flash level using the current value of the asymmetrical current signal and the current value of the symmetrical current signal.

[0135] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0136] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0137] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0138] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0139] In the description of this specification, the description with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0140] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for analyzing ground fault arc flash levels, characterized in that: include: determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current; generating a current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; The arc flash level is analyzed using the current value of the asymmetric current signal and the current value of the symmetric current signal.

2. The ground fault arc flash level analysis method according to claim 1, characterized in that: The step of determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current includes: identifying different current states from the ground fault current; The symmetrical current signal and the asymmetrical current signal are identified according to different current states.

3. The ground fault arc flash level analysis method according to claim 1, characterized in that: The step of generating the current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio includes: Determining a corresponding asymmetry factor according to the reactance-resistance ratio; The current value of the asymmetric current signal is calculated using the asymmetry factor and the current value of the symmetric current signal.

4. The ground fault arc flash level analysis method according to claim 1, characterized in that: The analyzing the arc flash level by using the current value of the asymmetric current signal and the current value of the symmetric current signal comprises: Calculating respectively using the current value of the asymmetric current signal and the current value of the symmetric current signal to obtain the corresponding incident energy of the arc flash; The different incident energies were compared and the arc flash levels were analyzed.

5. The ground fault arc flash level analysis method according to claim 1, characterized in that: Also includes: The corresponding ground fault current is simulated according to different grounding methods to analyze the arc flash level.

6. A ground fault arc flash level analysis device, characterized in that: include: A current determination unit, used for determining a symmetrical current signal and an asymmetrical current signal from the acquired ground fault current; a current value generating unit, configured to generate a current value of the asymmetric current signal according to the current value of the symmetrical current signal and the acquired reactance-resistance ratio; The arc flash analysis unit is used to analyze the arc flash level by using the current value of the asymmetric current signal and the current value of the symmetric current signal.

7. The ground fault arc flash level analysis device according to claim 6, characterized in that: The current determination unit comprises: A current state identification module, used for identifying different current states from the ground fault current; The current determination module is used to identify the symmetrical current signal and the asymmetrical current signal according to different current states.

8. The ground fault arc flash level analysis device according to claim 6, characterized in that: The current value generating unit comprises: A factor determination module, used to determine a corresponding asymmetry factor according to the reactance-resistance ratio; The current value calculation module is used to calculate the current value of the asymmetric current signal by using the asymmetry factor and the current value of the symmetric current signal.

9. The ground fault arc flash level analysis device according to claim 6, characterized in that: The arc flash analysis unit comprises: An incident energy calculation module, used to calculate the current value of the asymmetric current signal and the current value of the symmetric current signal respectively to obtain the corresponding incident energy of the arc flash; The arc flash analysis module is used to compare the different incident energies and analyze the arc flash level.

10. The ground fault arc flash level analysis device according to claim 6, characterized in that: Also includes: The simulation unit is used to simulate the corresponding ground fault current according to different grounding modes to analyze the arc flash level.

11. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 5 is implemented.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

13. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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