Power supply system fault section judgment method and device, electronic equipment and storage medium

Abstract

The application provides a power supply system fault interval judgment method and device, electronic equipment and storage medium, and belongs to the field of power system fault monitoring. The method comprises the following steps: calculating the power frequency transient information of all devices in the power supply system that has occurred a fault; performing frequency domain transformation on the power frequency transient information of each device to obtain corresponding frequency information, and determining the frequency with the maximum frequency domain amplitude in the frequency information of each device; if the difference between the frequencies with the maximum frequency domain amplitudes of two adjacent devices is greater than or equal to a first threshold value, it is determined that the fault interval of the power supply system is between the two devices. The device comprises a power frequency transient calculation module, a Fourier transform module and a fault interval judgment module. The application is not limited to the position of the fault, and the fault initial phase angle and the transition impedance of the fault point can all be used for fault interval judgment by using the power frequency transient information.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of power system fault monitoring, and particularly relates to a power supply system fault interval determination method and device, an electronic device and a storage medium. BACKGROUND

[0002] The distribution network affects the production and learning of the subordinate loads of the distribution network, and the 10kV self-closing through system affects the safe and reliable operation of the corresponding high-speed railway trains, so the safe operation of both the existing distribution network and the 10kV self-closing through line is crucial.

[0003] In the prior art, the traveling wave method is usually used for traveling wave fault location for the distribution network. When dealing with high-load lines, the traveling wave fault location fault monitoring device can realize fault monitoring of the line, but when dealing with multi-branch lines of the distribution network, the traveling wave fault location cannot effectively realize the main branch determination of the line, especially when dealing with the self-closing through line with long cable overhead mixed frame, the load current at the end thereof is small, and the influence of the length of the multi-section overhead cable mixed frame cable even cannot determine the fault interval.

[0004] When determining the fault of the self-closing through line, the method of the power frequency steady-state size or direction is usually used in the prior art. Since the structure of the self-closing through line itself is a cable overhead mixed frame and the line is long, the load thereof is low, and the system load current at the end of the line is low, there is an unstable situation when determining the size or direction, so there is the problem of inaccurate fault interval determination in the prior art. SUMMARY

[0005] Based on the above technical problems, the application provides a power supply system fault interval determination method, device, electronic device and storage medium.

[0006] In a first aspect, the application provides a power supply system fault interval determination method, comprising:

[0007] calculating power frequency transient information of all devices in the power supply system that has failed;

[0008] performing frequency domain transformation on the power frequency transient information of each device to obtain corresponding frequency information, and determining the frequency with the largest frequency domain amplitude in the frequency information of each device;

[0009] if the difference between the frequencies with the largest frequency domain amplitudes of two adjacent devices is greater than or equal to a first threshold value, it is determined that the fault interval of the power supply system is between the two devices.

[0010] The calculation of the power frequency transient information of all devices in the power supply system that has failed comprises:

[0011] The power frequency transient information is calculated based on the grounding resistance of the power supply system being less than or equal to a second threshold value or greater than a third threshold value.

[0012] The power supply system fault interval determination method further includes:

[0013] The line between the two devices is determined as a fault line, and the fault frequency of the fault line is between the series resonance frequencies corresponding to the frequencies with the maximum frequency domain amplitude of the two devices.

[0014] The series resonance frequency is calculated as follows:

[0015]

[0016] Where ω ks is the series resonance frequency of line k at different impedance angles, fault transition impedance or fault distance, L K is the zero sequence inductance of line k, and C K is the zero sequence capacitance of line k.

[0017] The power supply system fault interval determination method further includes:

[0018] In the two devices with the maximum frequency difference greater than or equal to a first threshold value, the device with the larger time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is determined as the post-fault device, and the device with the smaller time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is determined as the pre-fault device.

[0019] The time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is obtained by integrating the frequency with the maximum frequency domain amplitude.

[0020] The power frequency transient information of each device is frequency domain transformed to obtain corresponding frequency information, and the frequency with the maximum frequency domain amplitude in the frequency information of each device is determined, including:

[0021] The power frequency transient information of each device is frequency domain transformed using Fourier transform to obtain corresponding frequency information, and the frequency with the maximum frequency domain amplitude in the frequency information of each device is determined.

[0022] In a second aspect, the application provides a power distribution network fault interval determination device, including: a power frequency transient calculation module, a Fourier transform module, and a fault interval determination module.

[0023] The power frequency transient calculation module is configured to calculate the power frequency transient information of all devices in the power supply system that has failed;

[0024] The Fourier transform module is configured to frequency domain transform the power frequency transient information of each device to obtain corresponding frequency information, and determine the frequency with the maximum frequency domain amplitude in the frequency information of each device;

[0025] The fault interval determination module is configured to determine that the fault interval of the power supply system is between the two devices if the difference between the maximum frequency of the adjacent two devices is greater than or equal to the first threshold value.

[0026] In a third aspect, the present application provides an electronic device, comprising: one or more processors, and a memory, the memory storing instructions which, when executed by the one or more processors, cause the one or more processors to perform the power supply system fault interval determination method.

[0027] In a fourth aspect, the present application provides a computer-readable storage medium storing executable instructions which, when executed, cause a machine to perform the power supply system fault interval determination method.

[0028] Advantages:

[0029] The present application provides a power supply system fault interval determination method, device, electronic device and storage medium, which utilizes power frequency transient information to determine the fault interval, and presents obvious differences before and after the fault point. The present application is not limited to the location of the fault, and the fault initial phase angle, fault point transition impedance, and frequency distribution can all achieve fault interval determination for the neutral point non-effective grounding mode of the single power supply system. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 A power distribution network fault interval determination method flowchart of an embodiment of the present application;

[0031] Figure 2 A power distribution network fault interval determination method device principle diagram of an embodiment of the present application;

[0032] Figure 3 A single power supply system power supply equivalent circuit diagram of an embodiment of the present application;

[0033] Figure 4 A single power supply model small resistance grounding system equivalent circuit diagram of an embodiment of the present application;

[0034] Figure 5 A single power supply model large resistance grounding system equivalent circuit diagram of an embodiment of the present application;

[0035] Figure 6 A transient frequency distribution schematic diagram of an embodiment of the present application;

[0036] Figure 7 A simulated fault schematic diagram of an embodiment of the present application;

[0037] Figure 8Fig. 1 is a schematic diagram of the influence of the initial phase angle of a fault on the frequency spectrum according to an embodiment of the present application; wherein (a) is a schematic diagram of the current before a 2 ohm 2 km fault point; (b) is a schematic diagram of the current after a 2 ohm 2 km fault point; (c) is a schematic diagram of the current before a 2 ohm 8 km fault point; and (d) is a schematic diagram of the current after a 2 ohm 8 km fault point.

[0038] Figure 9 Fig. 2 is a schematic diagram of the influence of the fault distance on the frequency spectrum according to an embodiment of the present application; wherein (a) is a schematic diagram of the current before a 2 ohm 0 degree fault point; and (b) is a schematic diagram of the current after a 2 ohm 0 degree fault point.

[0039] Figure 10 Fig. 3 is a schematic diagram of the influence of the fault resistance on the frequency spectrum according to an embodiment of the present application; wherein (a) is a schematic diagram of the current before a 2 km fault point; (b) is a schematic diagram of the current after a 2 km fault point; (c) is a schematic diagram of the current before an 8 km fault point; and (d) is a schematic diagram of the current after an 8 km fault point. DETAILED DESCRIPTION

[0040] The present disclosure will be further described below with reference to the embodiments shown in the drawings.

[0041] The power distribution network affects the production and learning of the lower-level loads of the power distribution network, and the 10 kV self-closing through system affects the safe and reliable operation of the corresponding high-speed railway trains, so the safe operation of both the existing power distribution network and the 10 kV self-closing through line is crucial.

[0042] In the prior art, the traveling wave method is usually used for traveling wave fault location for the power distribution network. When dealing with high-load lines, the traveling wave fault location fault monitoring device can achieve fault monitoring of the line, but when dealing with multi-branch lines of the power distribution network, the traveling wave fault location cannot effectively achieve main branch determination of the line, especially when dealing with self-closing through lines with long cable overhead mixed racks, the load current at the end is small, and the influence of the length of the multi-section overhead cable mixed rack cable even cannot determine the fault interval.

[0043] When determining the fault of the self-closing through line, the method of the power frequency steady-state size or direction is usually used in the prior art. Since the structure of the self-closing through line itself is a cable overhead mixed rack and the line is long, the load is low, and it is a radiating structure, the load current of the system at the end of the line is low, and there is an unstable situation when determining the size or direction, so there is a problem of inaccurate fault interval determination in the prior art.

[0044] In the prior art, for the neutral point non-effective grounding mode power supply line such as distribution network and 10kV self-closing through line, the fault indicator is used for fault line selection and fault interval determination. The principle is that when the line fails, the current before the fault point is much larger than the current after the fault point, so the threshold setting of the fault indicator is used for fault determination. The fault indicator cannot realize fault line selection. For transient single-phase grounding, the fault indicator is prone to false alarm. For high resistance grounding, the fault indicator is prone to miss report.

[0045] Therefore, the application provides a power supply system fault interval determination method and device, electronic equipment and storage medium, which can effectively identify the fault interval of the power supply system based on the fault frequency distribution.

[0046] Embodiment one:

[0047] The embodiment provides a power supply system fault interval determination method, as shown in Figure 1 , which comprises the following steps:

[0048] Step S1: Calculate the power frequency transient information of all devices in the power supply system that has failed;

[0049] The embodiment takes a single power supply system as an example to elaborate the fault interval determination method of the application. The application will not be repeated for other types of power supply systems.

[0050] Based on the fact that the grounding resistance of the power supply system is less than or equal to a second threshold or greater than a third threshold, the power frequency transient information is calculated, and the specific implementation mode is as follows:

[0051] For a single power supply system, the equivalent circuit diagram is as shown in Figure 3 ;

[0052] In some cases, when the grounding resistance of the single power supply system is small, i.e. less than or equal to the second threshold, the corresponding equivalent circuit can be simplified as shown in Figure 4 , based on this equivalent circuit diagram, the first calculation formula is used to calculate the power frequency transient information under this condition;

[0053] The power frequency transient information includes current and voltage under power frequency transient state. In this embodiment, the power frequency transient characteristics of the current are used as the power frequency transient information. In other embodiments, the power frequency transient characteristics of the voltage can also be used. The first calculation formula is as follows:

[0054]

[0055]

[0056] Wherein, R0 is the equivalent resistance of the line, L0 is the equivalent inductance of the line, C0 is the equivalent capacitance of the line grounding, i cU is the current in the entire grounding loop when a ground fault occurs. m ω represents the amplitude of the system power supply voltage, and ω represents the system angular velocity. Let ω be the initial phase angle of the system. f Let τ be the equivalent system resonant frequency, e be the natural logarithm, and τ be the t-value. c C0 is the system equivalent capacitance, C0 is the charging time, and τ is the charging time. L Let L0 be the system equivalent inductance, and L0 be the charging time. d For reactive current, i Cm i is the reactive current of the system capacitor. Lm This represents the reactive current of the system inductor.

[0057] In other cases, the grounding resistance of a single-power supply system is relatively large, exceeding the third threshold. Its equivalent circuit diagram is shown below. Figure 5 As shown, based on this equivalent circuit diagram, the power frequency transient information is calculated using the second calculation formula, which is as follows:

[0058]

[0059] Where R0 is the equivalent resistance of the line, L0 is the equivalent inductive reactance of the line, C0 is the equivalent capacitive reactance of the line grounding, i0 is the equivalent system current of the single-power supply system after the fault, and U m ω represents the amplitude of the system power supply voltage, and ω represents the system angular velocity. This is the initial phase angle of the system.

[0060] Step S2: Perform frequency domain transformation on the power frequency transient information of each device to obtain the corresponding frequency information, and determine the frequency with the largest frequency domain amplitude in the frequency information of each device;

[0061] This embodiment utilizes Fourier transform to perform frequency domain transformation on the power frequency transient information of each device to obtain the corresponding frequency information, and determines the frequency with the largest frequency domain amplitude in the frequency information of each device. The frequency with the largest frequency domain amplitude in the frequency information of each device is the main frequency after Fourier transform of the power frequency transient information of each device. All calculated main frequencies should fall within the series resonant frequency distribution range. Using Fourier transform to obtain the main frequency is common knowledge to those skilled in the art, and this application will not elaborate further.

[0062] Step S3: If the frequency difference between the two adjacent devices with the largest frequency domain amplitude is greater than or equal to the first threshold, then the fault interval of the power supply system is determined to be between the two devices.

[0063] In this embodiment, if the difference in the main frequency after Fourier transform of two adjacent devices is greater than or equal to the first threshold, the fault range of the power supply system is determined to be between the two adjacent devices.

[0064] The aforementioned method for determining fault zones in a power supply system further includes:

[0065] determining that a line between the two devices is a fault line, a fault frequency of the fault line being between series resonance frequencies corresponding to the two device main frequencies, as shown in Figure 6

[0066] The series resonance frequency is calculated as follows:

[0067]

[0068] where ω ks is the series resonance frequency of line k at different impedance angles, fault transition impedances or fault distances, L K is the zero sequence inductance of line k, and C K is the zero sequence capacitance of line k.

[0069] The power supply system fault interval determination method further comprises:

[0070] Among the two devices whose main frequency difference is greater than or equal to the first threshold, the device with a large time domain amplitude corresponding to the main frequency is determined as the post-fault device, and the device with a small time domain amplitude corresponding to the main frequency is determined as the pre-fault device.

[0071] As shown in Figure 6 , the horizontal axis represents the frequency distribution of resonance under different fault impedances, different fault distances and different fault initial phase angles, and the vertical axis represents the frequency distribution of resonance, f1 is the main frequency of the pre-fault device after Fourier transform of the power frequency transient information, and f2 is the main frequency of the post-fault device after Fourier transform of the power frequency transient information. The main frequency f1 of the pre-fault device after Fourier transform of the power frequency transient information is much smaller than the main frequency f2 of the post-fault device after Fourier transform of the power frequency transient information.

[0072] The time domain amplitude corresponding to the frequency with the largest frequency domain amplitude is obtained by integrating the frequency with the largest frequency domain amplitude.

[0073] As shown in Figure 7 , G is the fault point, f1 is the main frequency of the power frequency transient information of device 1 after Fourier transform, f2 is the main frequency of the power frequency transient information of device 2 after Fourier transform, f3 is the main frequency of the power frequency transient information of device 3 after Fourier transform, and f4 is the main frequency of the power frequency transient information of device 4 after Fourier transform. The pre-fault device, the main frequency f2 is much smaller than the post-fault main frequency f3.

[0074] The frequency difference corresponding to the maximum integral value solved by all monitoring terminals before the fault point is basically 0 (f1-f2), and the frequency difference corresponding to the maximum integral value solved after the fault point is basically 0 (f3-f4), but f2 and f3 are obviously different, as shown in Figure 8 ​(a) f2 is 1500 Hz, as shown in Figure 8 (b) f3 is 3800 Hz.

[0075] The fault interval can be determined by the frequency difference. The place with obvious difference is the fault interval, that is Figure 8 (a) f2 and f3 shown in Figure 8 (b).

[0076] Similarly, the impedance angle, fault transition impedance, and fault distance have the same rule, that is, the present application is not limited to the impedance angle, fault transition impedance, and fault distance. The fault interval can be determined by the difference between the maximum frequency of the adjacent two equipment frequency domain amplitudes. The following simulation results show the above conclusions:

[0077] The influence of fault initial phase angle on frequency spectrum, as shown in Figure 8 (a), (b), (c), (d), the following rules are obtained: (1) In each feeder, the amplitude difference of each frequency band spectrum component is large. The fault line has the maximum spectrum amplitude. In the normal line, the spectrum amplitude of overhead line is much lower than that of mixed line and cable line. (2) When the fault initial phase angle is small, the fault line contains a large component of direct current component, that is, inductance current component, while the direct current component in the non-fault line is small, that is, without inductance current. (3) With the increase of fault initial phase angle, the content of direct current component gradually decreases, that is, the inductance current component gradually decreases, which is consistent with the theoretical analysis conclusion. (4) The frequency transient information after Fourier transform is mainly concentrated in 1000HZ, which increases with the increase of fault initial phase angle.

[0078] The influence of fault distance on frequency spectrum, as shown in Figure 9 (a), Figure 9 (b), the following rules can be seen: the closer the fault point to the bus, the lower the main component of the frequency transient information after Fourier transform. When the fault point is at the end of the line, the main component of the frequency spectrum is about 1000HZ, and when it is close to the head end, it is reduced to about 300HZ. When the line head end is faulty, the main component of the frequency spectrum of the pure overhead line moves to the high frequency band. The amplitude of the main component of the frequency spectrum slightly decreases with the decrease of fault distance.

[0079] The influence of fault resistance on frequency spectrum, as shown in Figure 10(a), 10(b), 10(c), 10(d), it can be seen that the following rules, (1) when the fault resistance is small, the frequency spectrum of the frequency transient information after Fourier transform is mainly composed of high frequency components around 1000 Hz. (2) When the fault resistance increases, the frequency spectrum of the frequency transient information after Fourier transform moves to the low frequency band, and the amplitude gradually becomes smaller. (3) When the fault resistance increases, the inductance branch of the arc suppression coil cannot be ignored, and the frequency spectrum of the frequency transient information after Fourier transform is close to the power frequency. For this resonant grounding system, when the fault resistance reaches 2kΩ, the main component of the frequency spectrum tends to the power frequency, and in the time domain, it is manifested as the slow rise of the amplitude of the zero sequence current of each feeder.

[0080] In this embodiment, the power frequency transient information of all devices in the single power supply system is calculated. The Fourier transform of the power frequency transient information of each device is performed to obtain the corresponding frequency information, and the frequency with the maximum frequency domain amplitude in the frequency information of each device is determined. That is, after the Fourier transform of the power frequency transient information of each device, the main frequency after Fourier transform is obtained. If the difference between the main frequencies after Fourier transform of two adjacent devices is greater than or equal to a first threshold value, it is determined that the fault interval of the power supply system is between the two devices, and the line between the two devices is determined as the fault line. The fault frequency of the fault line is between the series resonance frequencies corresponding to the main frequencies after Fourier transform of the two devices. In this embodiment, simulation results are used as evidence to prove the effectiveness of this embodiment. From the simulation results, this embodiment is not limited to the location of the fault, and the fault initial phase angle and the fault point transition impedance can all be used to determine the fault interval by using the power frequency transient information.

[0081] Embodiment two:

[0082] This embodiment proposes a device for judging the fault interval of a power distribution network, as shown in Figure 2 The device includes a power frequency transient calculation module, a Fourier transform module, and a fault interval judgment module.

[0083] The power frequency transient calculation module is used to calculate the power frequency transient information of all devices in the power supply system that has occurred a fault.

[0084] The Fourier transform module is used to perform frequency domain transformation on the power frequency transient information of each device to obtain the corresponding frequency information, and determine the frequency with the maximum frequency domain amplitude in the frequency information of each device.

[0085] The fault interval judgment module is used to determine that the fault interval of the power supply system is between two adjacent devices if the difference between the frequencies with the maximum frequency domain amplitudes of the two devices is greater than or equal to a first threshold value.

[0086] The power frequency transient information of all devices in the power supply system that has occurred a fault includes:

[0087] The power frequency transient information is calculated based on the ground resistance of the power supply system being less than or equal to a second threshold value or greater than a third threshold value.

[0088] The power supply system fault interval determination method further includes:

[0089] The line between the two devices is determined as a fault line, and the fault frequency of the fault line is between the series resonance frequency corresponding to the frequency with the maximum frequency domain amplitude of the two devices.

[0090] The series resonance frequency is calculated as follows:

[0091]

[0092] Where ω ks is the series resonance frequency of line k at different impedance angles, fault transition impedance or fault distance, L K is the zero sequence inductance of line k, and C K is the zero sequence capacitance of line k.

[0093] The power supply system fault interval determination method further includes:

[0094] In the two devices with the largest frequency difference greater than or equal to a first threshold value, the device with the largest time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is determined as the post-fault device, and the device with the smallest time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is determined as the pre-fault device.

[0095] The time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is obtained by integrating the frequency with the maximum frequency domain amplitude.

[0096] The power frequency transient information of each device is frequency domain transformed to obtain corresponding frequency information, and the frequency with the maximum frequency domain amplitude in the frequency information of each device is determined, including:

[0097] The power frequency transient information of each device is frequency domain transformed using Fourier transform to obtain corresponding frequency information, and the frequency with the maximum frequency domain amplitude in the frequency information of each device is determined.

[0098] The embodiment proposes a power distribution network fault interval determination device, a power frequency transient calculation module, a Fourier transform module, and a fault interval determination module, which cooperate with each other. Regardless of the location of the fault, the fault initial phase angle, and the fault point transition impedance, the power frequency transient information can be used to determine the fault interval.

[0099] Embodiment three:

[0100] The embodiment provides an electronic device, comprising one or more processors and a memory storing instructions which, when executed by the one or more processors, cause the one or more processors to perform the power supply system fault interval determination method.

[0101] The power supply system fault interval determination method comprises the following steps.

[0102] Step S1: calculating power frequency transient information of all devices in the power supply system in which a fault occurs.

[0103] Step S2: performing frequency domain transformation on the power frequency transient information of each device to obtain corresponding frequency information, and determining a frequency with the maximum frequency domain amplitude in the frequency information of each device.

[0104] Step S2: if a difference between the frequencies with the maximum frequency domain amplitude of two adjacent devices is greater than or equal to a first threshold value, it is determined that the fault interval of the power supply system is between the two devices.

[0105] The power frequency transient information of all devices in the power supply system in which a fault occurs comprises the following steps.

[0106] The power frequency transient information is calculated based on the fact that the grounding resistance of the power supply system is less than or equal to a second threshold value or greater than a third threshold value.

[0107] The power supply system fault interval determination method further comprises the following steps.

[0108] The line between the two devices is determined as a fault line, and a fault frequency of the fault line is between the series resonance frequencies corresponding to the frequencies with the maximum frequency domain amplitude of the two devices.

[0109] The series resonance frequency is calculated according to the following formula.

[0110]

[0111] wherein ω ks is a series resonance frequency of the line k under different impedance angles, fault transition impedances or fault distances, L K is a zero sequence inductance of the line k, and C K is a zero sequence capacitance of the line k.

[0112] The power supply system fault interval determination method further comprises the following steps.

[0113] In the two devices with the maximum frequency difference greater than or equal to the first threshold value, a device with a large time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is determined as a post-fault device, and a device with a small time domain amplitude corresponding to the frequency with the maximum frequency domain amplitude is determined as a pre-fault device.

[0114] The time domain amplitude corresponding to the frequency with the largest frequency domain amplitude is obtained by integrating the frequency with the largest frequency domain amplitude.

[0115] The power frequency transient information of each device is subjected to frequency domain transformation to obtain corresponding frequency information, and the frequency with the largest frequency domain amplitude in the frequency information of each device is determined.

[0116] The power frequency transient information of each device is subjected to frequency domain transformation to obtain corresponding frequency information, and the frequency with the largest frequency domain amplitude in the frequency information of each device is determined.

[0117] The electronic device can be a mobile phone, a computer, or a tablet computer, etc., comprising a memory and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor to implement the power supply system fault interval determination method as described in the embodiments. It can be understood that the electronic device can further comprise an input / output (I / O) interface and a communication component.

[0118] The processor is configured to execute all or part of the steps of the power supply system fault interval determination method as described in the above embodiments. The memory is configured to store various types of data, which can include, for example, instructions of any application program or method in the electronic device, and application program related data.

[0119] The processor can be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic elements, and is configured to execute the power supply system fault interval determination method as described in the above embodiments.

[0120] Embodiment Four

[0121] The embodiment provides a computer readable storage medium storing executable instructions, wherein the instructions, when executed, cause a machine to execute the power supply system fault interval determination method.

[0122] The power supply system fault interval determination method comprises:

[0123] Step S1: calculating power frequency transient information of all devices in the power supply system that has failed;

[0124] Step S2: performing frequency domain transformation on the power frequency transient information of each device to obtain corresponding frequency information, and determining the frequency with the largest frequency domain amplitude in the frequency information of each device;

[0125] Step S2: if the difference between the frequencies with the largest frequency domain amplitudes of the two adjacent devices is greater than or equal to the first threshold value, determining that the fault interval of the power supply system is between the two devices.

[0126] The power frequency transient information of all devices in the power supply system that has failed is calculated, including:

[0127] The power frequency transient information is calculated based on the grounding resistance of the power supply system being less than or equal to a second threshold value or greater than a third threshold value.

[0128] The power supply system fault interval determination method further includes:

[0129] The line between the two devices is determined as a fault line, and the fault frequency of the fault line is between the series resonance frequencies corresponding to the frequencies with the largest frequency domain amplitudes of the two devices.

[0130] The series resonance frequency is calculated as follows:

[0131]

[0132] where ω ks is the series resonance frequency of line k under different impedance angles, fault transient impedance or fault distance, L K is the zero sequence inductance of line k, and C K is the zero sequence capacitance of line k.

[0133] The power supply system fault interval determination method further includes:

[0134] Among the two devices with the largest frequency difference greater than or equal to the first threshold value, the device with the larger time domain amplitude corresponding to the frequency with the largest frequency domain amplitude is determined as the post-fault device, and the device with the smaller time domain amplitude corresponding to the frequency with the largest frequency domain amplitude is determined as the pre-fault device.

[0135] The time domain amplitude corresponding to the frequency with the largest frequency domain amplitude is obtained by integrating the frequency with the largest frequency domain amplitude.

[0136] The power frequency transient information of each device is transformed into frequency domain to obtain corresponding frequency information, and the frequency with the largest frequency domain amplitude in the frequency information of each device is determined, including:

[0137] The power frequency transient information of each device is transformed into frequency domain using Fourier transform to obtain corresponding frequency information, and the frequency with the largest frequency domain amplitude in the frequency information of each device is determined.

[0138] Based on such understanding, the technical solution of the present application, essentially or the part that contributes to the prior art, or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the power supply system fault interval determination method described in various embodiments of the present application.

[0139] The aforementioned storage medium includes a flash memory, a hard disk, a multimedia card, a card-type memory (such as an SD (Secure Digital Memory Card) or a DX (Memory Data Register, MDR) memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, a server, an APP (Application) application store, and various media that can store program check codes, on which a computer program is stored, and the computer program can implement each step of the power supply system fault interval determination method when executed by a processor.

[0140] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0141] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the described device embodiment is merely illustrative. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0142] In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, and the like, unless otherwise explicitly and specifically limited. All directional indications (such as upper, lower, left, right, front, rear, top, bottom, etc.) in the embodiments of the present application are intended to facilitate the understanding of relative positions, movement conditions, and the like between components, and are not intended to indicate the specific posture of the components. If the specific posture changes, the directional indications also change accordingly. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes other steps or units not listed or optionally includes other steps or units inherent to such processes, methods, products or devices.

[0143] In addition, the reference to "embodiments" in this document means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0144] The above merely describes a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims. The above merely describes a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, etc. made within the spirit and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for determining fault zones in a power supply system, characterized in that, include: Calculate the power frequency transient information of all equipment in the power supply system where the fault occurred; The power frequency transient information of each device is transformed in the frequency domain to obtain the corresponding frequency information, and the frequency with the largest frequency domain amplitude in the frequency information of each device is determined. If the frequency difference between the two adjacent devices with the largest frequency domain amplitude is greater than or equal to the first threshold, then the fault interval of the power supply system is determined to be between the two devices. Also includes: The line between the two devices is identified as a faulty line, and the fault frequency of the faulty line is between the series resonant frequencies corresponding to the frequencies with the largest frequency domain amplitudes of the two devices. The series resonant frequency is calculated as follows: in, Let k be the series resonant frequency of line k under different impedance angles, fault transition impedances, or fault distances. Let k be the zero-sequence inductance of line k. Let be the zero-sequence capacitance of line k; Also includes: Among two devices whose maximum frequency difference is greater than or equal to the first threshold, the device with the largest time-domain amplitude corresponding to the frequency with the largest frequency-domain amplitude is identified as the device after the fault point, and the device with the smaller time-domain amplitude corresponding to the frequency with the largest frequency-domain amplitude is identified as the device before the fault point.

2. The method for determining fault zones in a power supply system as described in claim 1, characterized in that, The calculation of power frequency transient information for all equipment in the power supply system where the fault occurred includes: The power frequency transient information is calculated based on the grounding resistance of the power supply system being less than or equal to the second threshold or greater than the third threshold.

3. The method for determining fault zones in a power supply system as described in claim 1, characterized in that, The time-domain amplitude corresponding to the frequency with the largest frequency domain amplitude is obtained by integrating the frequency with the largest frequency domain amplitude.

4. The method for determining fault zones in a power supply system as described in claim 1, characterized in that, The step of performing frequency domain transformation on the power frequency transient information of each device to obtain the corresponding frequency information, and determining the frequency with the largest frequency domain amplitude in the frequency information of each device, includes: The power frequency transient information of each device is transformed in the frequency domain using Fourier transform to obtain the corresponding frequency information, and the frequency with the largest frequency domain amplitude in the frequency information of each device is determined.

5. A device for determining fault sections in a distribution network for implementing the power supply system fault section determination method according to any one of claims 1-4, characterized in that, include: Power frequency transient calculation module, Fourier transform module, fault interval judgment module; The power frequency transient calculation module is used to calculate the power frequency transient information of all equipment in the power supply system in the event of a fault. The Fourier transform module is used to perform frequency domain transformation on the power frequency transient information of each device to obtain the corresponding frequency information, and to determine the frequency with the largest frequency domain amplitude in the frequency information of each device. The fault interval determination module is used to determine that the fault interval of the power supply system is between the two devices if the difference between the frequencies with the largest frequency domain amplitude of two adjacent devices is greater than or equal to a first threshold.

6. An electronic device, characterized in that, include: One or more processors, and a memory storing instructions that, when executed by the one or more processors, cause the one or more processors to perform the power supply system fault range determination method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, It stores executable instructions, which, when executed, cause the machine to perform the power supply system fault zone determination method according to any one of claims 1 to 4.

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