A method, apparatus, and computer program product for determining the nature of a fault in a series of steps
By analyzing electrical quantity data in power system fault recording files and combining phase and amplitude relationships, a full-dimensional diagnosis of phase-to-phase grounding faults is achieved, solving the problem of inaccurate fault diagnosis in existing technologies and improving the accuracy of fault diagnosis and the system's rapid response capability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN POWER SUPPLY BUREAU
- Filing Date
- 2026-02-27
- Publication Date
- 2026-06-02
AI Technical Summary
Existing technologies cannot systematically analyze the transition resistance characteristics, precise spatial location, and directionality of phase-to-phase grounding faults in power systems, leading to inaccurate fault diagnosis and affecting the reliability and rapid response capability of relay protection strategy optimization and system fault diagnosis.
By acquiring three-phase voltage, current, and zero-sequence voltage and current data from power system fault recording files, and combining phase and amplitude relationships, the fault direction, nature, and location of phase-to-phase grounding faults can be determined, enabling comprehensive and accurate diagnosis of phase-to-phase grounding faults.
It enables accurate determination of phase-to-phase grounding faults, identification of fault direction, differentiation of fault nature, and qualitative judgment of fault location, improving the accuracy and reliability of fault diagnosis, supporting the optimization of relay protection devices, and meeting the needs of modern smart grids for accurate fault diagnosis and self-healing control.
Smart Images
Figure CN122131191A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power system technology, and specifically to a method, apparatus, and computer program product for determining the nature of phase-to-phase faults. Background Technology
[0002] During power system operation, various types of faults occur, primarily including single-phase grounding faults, phase-to-phase short-circuit faults, two-phase grounding faults, three-phase short-circuit faults, and open-circuit faults. When a fault occurs, relay protection professionals rely on fault recorders to record transient current and voltage waveform data. By analyzing fault reports, they diagnose the detailed characteristics of the fault, including fault type (e.g., single-phase grounding, phase-to-phase short circuit), fault nature (whether it involves a transition resistance or is a metallic fault), fault location (the beginning, middle, or end of the transmission line), and fault direction (forward or reverse). Among these, the transition resistance characteristic (reflecting the resistance value at the fault point) is a key parameter for distinguishing the severity of the fault, while the fault location and direction directly affect the operating logic and selectivity of the protection device.
[0003] However, in existing technologies, professional fault analysis is generally limited to the preliminary identification of fault categories (such as distinguishing between single-phase grounding and phase-to-phase faults), failing to systematically analyze the transition resistance characteristics, precise spatial location, and directionality of the fault. For example, existing analysis methods are usually based only on a rough comparison of waveform amplitude and phase, lacking quantitative calculation of transition resistance (such as extraction through impedance tracing or fault components), and do not combine line parameters to achieve high-precision fault location (such as using traveling wave ranging or impedance methods). This lack of analytical depth makes it impossible to accurately assess the essential characteristics of the fault (such as the impact of transition resistance on fault current), thus restricting the optimization of relay protection strategies, reducing the reliability and rapid response capability of system fault diagnosis, and making it difficult to meet the needs of modern smart grids for accurate fault diagnosis and self-healing control. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a method, device and computer program product for judging the nature of phase-to-phase faults, so as to realize the full-dimensional accurate diagnosis of phase-to-phase faults in power systems and meet the practical application needs of modern smart grids for accurate fault diagnosis and self-healing control.
[0005] To solve the above-mentioned technical problems, the present invention provides a method for determining the nature of a fault in a series of steps, comprising: Step S1: Obtain the fault recording file of the power system, and extract the three-phase voltage data, three-phase current data, zero-sequence voltage data and zero-sequence current data from the fault recording file. Step S2: Based on the extracted three-phase voltage data, three-phase current data, zero-sequence voltage data, and zero-sequence current data, determine whether a phase-to-phase grounding fault has occurred. If a phase-to-phase grounding fault is determined, then identify the faulty phase and the non-faulty phase. Step S3: Based on at least one of the following phase relationships, determine whether the fault direction of the phase-to-phase grounding fault is a positive or negative fault: the phase relationship between the fault phase current and the non-fault phase voltage, the phase relationship between the zero-sequence current and the non-fault phase voltage, and the phase relationship between the zero-sequence current and the zero-sequence voltage. Step S4: Based on the current amplitude relationship between the two faulted phases, the voltage amplitude relationship between the two faulted phases, the phase relationship between the zero-sequence voltage and the voltage of the non-faulted phase, and the phase relationship between the current of the non-faulted phase and the voltage of the non-faulted phase, determine whether the fault nature of the phase-to-phase grounding fault is a metallic grounding fault or a fault through a transition resistor. Step S5: Based on the amplitude and phase characteristics of the fault phase voltage, the amplitude characteristics of the fault phase current, and the amplitude and phase characteristics of the zero-sequence current, determine the fault location of the phase-to-phase grounding fault.
[0006] Preferably, in step S2, a phase-to-phase grounding fault is determined to have occurred when all of the following conditions are met simultaneously: Two of the three-phase voltages have decreased voltage amplitude, while the voltage amplitude and phase of the remaining phase remain unchanged, and a zero-sequence voltage appears. The amplitudes of the two phase currents corresponding to the voltage drop increase synchronously at the moment the voltage drops, and zero-sequence current appears. The current amplitude of the phase whose voltage amplitude did not decrease and whose phase did not change remained unchanged. At the same time, the two phases with decreased voltage and increased current are identified as faulty phases, while the phase with no change in voltage and current is identified as a non-faulty phase.
[0007] Preferably, in step S3, the phase-to-phase grounding fault is determined to be a positive-direction fault when any of the following conditions are met: The zero-sequence current leads the non-faulty phase voltage by 95°~110°, or the zero-sequence current leads the zero-sequence voltage by 95°~110°. The phase of the leading phase current in the two faulted phase currents leads the phase voltage of the non-faulted phase current by 150°~190°. The phase of the lagging phase current in the two faulted phase currents leads the phase voltage of the non-faulted phase by 10°~50°.
[0008] Preferably, in step S3, if any of the determination conditions for the positive direction fault are not met, the phase-to-phase fault is determined to be a reverse direction fault.
[0009] Preferably, in step S4, the phase-to-phase grounding fault is determined to be a fault via a transition resistor when any of the following conditions are met: The current amplitudes of the two faulty phases are not equal, and the current amplitude of the leading phase is greater than that of the lagging phase. The voltage amplitudes of the two faulty phases are not equal; The zero-sequence voltage is out of phase with the voltage of the non-faulty phase; The angle by which the current of the non-faulty phase lags behind the voltage of the non-faulty phase is less than 80°.
[0010] Preferably, in step S4, if any of the determination conditions for the fault via the transition resistor are not met, the phase-to-phase grounding fault is determined to be a metallic grounding fault.
[0011] Preferably, in step S5, the phase-to-phase grounding fault is determined to be a fault at the line exit when any of the following conditions are met: The voltage amplitude of the two faulty phases is zero or lower than the preset amplitude threshold, and the voltage phase of the two faulty phases is the same; The voltages of the two faulted phases are in phase with the zero-sequence current.
[0012] Preferably, in step S5, the larger the current amplitude of the two fault phases, the closer the distance between the fault point and the measurement point; the larger the amplitude of the zero-sequence current, the closer the distance between the fault point and the measurement point.
[0013] The present invention also provides a fault nature determination device in series, comprising: One or more processors; Memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, and the one or more applications are configured to perform the related fault nature determination method.
[0014] The present invention also provides a computer program product, including computer instructions, which instruct a computer device to perform operations corresponding to the related fault nature determination method.
[0015] The beneficial effects of this invention are as follows: Based on power system fault recording files, this invention sequentially completes the accurate determination of phase-to-phase grounding faults, identification of the forward and reverse directions of the fault, differentiation of the metallic nature of the fault and its location through transition resistance, and qualitative judgment of the fault location. This overcomes the limitations of existing technologies that can only preliminarily identify fault categories, achieving a systematic and comprehensive analysis of the core characteristics of phase-to-phase grounding faults. This invention integrates multi-dimensional electrical characteristics of three-phase voltage, current, and zero-sequence components to form judgment rules. From data extraction to judgment at each stage, the design revolves around the specific electrical characteristics of phase-to-phase grounding faults. It avoids false fault judgments through multi-condition cross-validation and relies on the amplitude and phase characteristics of the fault phase and zero-sequence components to achieve accurate identification of the fault direction, nature, and location, significantly improving the accuracy and reliability of phase-to-phase grounding fault diagnosis. Simultaneously, this invention provides relay protection professionals with comprehensive and accurate fault characteristic data, provides effective technical support for optimizing the operating logic of relay protection devices, enhances the rapid response capability of power system fault diagnosis, meets the actual needs of modern smart grids for accurate fault diagnosis and self-healing control, and ensures the safe and stable operation of the power system. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a flowchart illustrating a method for determining the nature of a fault in a series according to an embodiment of the present invention. Detailed Implementation
[0018] The following description of the embodiments is taken with reference to the accompanying drawings, which illustrate specific embodiments in which the invention can be implemented.
[0019] Please refer to Figure 1 As shown, an embodiment of the present invention provides a method for determining the nature of a fault in a sequential manner, comprising: Step S1: Obtain the fault recording file of the power system, and extract the three-phase voltage data, three-phase current data, zero-sequence voltage data and zero-sequence current data from the fault recording file. Step S2: Based on the extracted three-phase voltage data, three-phase current data, zero-sequence voltage data, and zero-sequence current data, determine whether a phase-to-phase grounding fault has occurred. If a phase-to-phase grounding fault is determined, then identify the faulty phase and the non-faulty phase. Step S3: Based on at least one of the following phase relationships, determine whether the fault direction of the phase-to-phase grounding fault is a positive or negative fault: the phase relationship between the fault phase current and the non-fault phase voltage, the phase relationship between the zero-sequence current and the non-fault phase voltage, and the phase relationship between the zero-sequence current and the zero-sequence voltage. Step S4: Based on the current amplitude relationship between the two faulted phases, the voltage amplitude relationship between the two faulted phases, the phase relationship between the zero-sequence voltage and the voltage of the non-faulted phase, and the phase relationship between the current of the non-faulted phase and the voltage of the non-faulted phase, determine whether the fault nature of the phase-to-phase grounding fault is a metallic grounding fault or a fault through a transition resistor. Step S5: Based on the amplitude and phase characteristics of the fault phase voltage, the amplitude characteristics of the fault phase current, and the amplitude and phase characteristics of the zero-sequence current, determine the fault location of the phase-to-phase grounding fault.
[0020] Specifically, this embodiment of the invention takes a phase-to-phase fault in phases A and B of a power system as an example to illustrate the method for judging the nature of phase-to-phase grounding faults described in this invention. For two-phase phase-to-phase faults in phases A and C or phases B and C of a power system, the judgment steps and judgment conditions of this embodiment can be followed. The method for judging the nature of phase-to-phase grounding faults of this invention is based on the fault recording file generated by the power system fault recorder. By extracting various electrical quantity data during the fault occurrence period in the fault recording file, the determination of phase-to-phase grounding faults, the judgment of fault direction, the differentiation of fault nature, and the determination of fault location are completed in sequence, ultimately realizing a systematic and precise analysis of the core characteristics of phase-to-phase grounding faults in the power system.
[0021] Step S1 is used to acquire fault waveform files and extract electrical quantity data. Specifically, the fault waveform files of the power system are acquired, and the amplitude and phase information of the three-phase phase voltages (phase A voltage, phase B voltage, and phase C voltage) and three-phase phase currents (phase A current, phase B current, and phase C current) during the fault occurrence period are extracted from the fault waveform files. At the same time, the presence or absence of zero-sequence voltage and zero-sequence current, as well as their corresponding amplitude and phase information, are extracted, providing a complete and accurate electrical quantity data foundation for fault judgment in subsequent steps.
[0022] Step S2 determines an inter-phase grounding fault and identifies the faulty and non-faulty phases. Specifically, based on the extracted three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current data, it is determined whether an inter-phase grounding fault has occurred in the power system. An inter-phase grounding fault is determined to have occurred when all of the following conditions are met, and the faulty and non-faulty phases are simultaneously identified: (1) Among the three-phase voltages A, B and C, the voltage amplitudes of phase A and phase B decreased significantly, while the voltage amplitude and phase of phase C remained almost unchanged, and zero-sequence voltage was detected in the power system. (2) The currents of phase A and phase B corresponding to the voltage drop of phase A and phase B increase synchronously at the same moment when the voltage amplitude of phase A and phase B decreases, and zero-sequence current is detected in the power system. (3) The current amplitude of the non-faulty phase C phase does not change.
[0023] When all the above conditions are met, phases A and B, where the voltage amplitude decreases and the current amplitude increases, are determined to be faulty phases, while phase C, where neither voltage nor current shows obvious abnormalities, is determined to be a non-faulty phase.
[0024] Step S3 determines the fault direction of the phase-to-phase grounding fault. Specifically, based on at least one of the phase relationships between the fault phase current and the non-fault phase voltage, the phase relationship between the zero-sequence current and the non-fault phase voltage, and the phase relationship between the zero-sequence current and the zero-sequence voltage, the fault direction of the phase-to-phase grounding fault is determined to be either a forward fault or a reverse fault.
[0025] A phase-to-phase fault is determined to be a forward fault if any of the following conditions are met; otherwise, it is determined to be a reverse fault: (1) The zero-sequence current leads the voltage of the non-faulty phase C by 95°~110°, or the zero-sequence current leads the zero-sequence voltage by 95°~110°; (2) The leading phase current in the two faulted phase currents, namely the A phase current, leads the non-faulted phase C phase voltage by 150°~190°. (3) The lagging phase current in the two fault phase currents, namely the B phase current, leads the non-fault phase C phase voltage by 10°~50°.
[0026] Step S4 determines the nature of the phase-to-phase grounding fault. Specifically, based on the current amplitude relationship between the two faulty phases, the voltage amplitude relationship between the two faulty phases, the phase relationship between the zero-sequence voltage and the voltage of the non-faulty phase, and the phase relationship between the current of the non-faulty phase and the voltage of the non-faulty phase, the nature of the phase-to-phase grounding fault is determined to be either a metallic grounding fault or a fault through a transition resistor.
[0027] A phase-to-phase ground fault is determined to be a fault through a transition resistor if any of the following conditions are met; otherwise, the phase-to-phase ground fault is determined to be a metallic ground fault: (1) The current amplitudes of the two fault phases, namely phase A and phase B, are not equal, and the current amplitude of the leading phase A is greater than that of the lagging phase B. (2) The voltage amplitudes of the two faulty phases, namely phase A and phase B, are not equal; (3) The zero-sequence voltage and the phase voltage of the non-faulty phase C are out of phase; (4) The angle by which the current of the non-faulty phase C lags behind the voltage of the non-faulty phase C is less than 80°.
[0028] Step S5 determines the location of the phase-to-phase grounding fault. Specifically, based on the amplitude and phase characteristics of the fault phase voltage, the amplitude characteristics of the fault phase current, and the amplitude and phase characteristics of the zero-sequence current, the location of the phase-to-phase grounding fault is qualitatively determined, which is divided into two parts: determining the fault location at the line exit and determining the distance to the fault point. Fault determination at the line exit: A phase-to-phase grounding fault is determined to be a fault at the transmission line exit if any of the following conditions are met: (1) The voltage amplitude of the two faulty phases, namely phase A and phase B, is zero or small (e.g., below the preset amplitude threshold), and the phases of phase A and phase B are the same. (2) The voltage and zero-sequence current of the two fault phases, namely phase A and phase B, are in phase.
[0029] Fault location proximity determination: The distance between the fault location and the measurement point is determined based on the amplitude characteristics of the fault phase current and zero-sequence current. The specific rules are as follows: (1) The larger the current amplitude of the two faulty phases, namely phase A and phase B, the closer the distance between the fault point and the measurement point; (2) The larger the amplitude of the zero-sequence current, the closer the fault point is to the measurement point.
[0030] Corresponding to the method for determining the nature of a fault in a phase-to-phase manner in Embodiment 1 of the present invention, Embodiment 2 of the present invention also provides a device for determining the nature of a fault in a phase-to-phase manner, comprising: One or more processors; Memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, and the one or more applications are configured to perform the related fault nature determination method.
[0031] Corresponding to the method for determining the nature of a fault in a related manner in Embodiment 1 of the present invention, Embodiment 3 of the present invention also provides a computer program product, including computer instructions, wherein the computer instructions instruct a computer device to perform the operation corresponding to the method for determining the nature of a fault in a related manner.
[0032] Preferably, the processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor, or the processor can be any conventional processor. The processor is the control center of the device, connecting various parts of the device through various interfaces and lines.
[0033] The memory mainly includes a program storage area and a data storage area. The program storage area can store the operating system, applications required for at least one function, etc., while the data storage area can store related data, etc. Furthermore, the memory can be a high-speed random access memory, or a non-volatile memory, such as a plug-in hard drive, a SmartMedia Card (SMC), a Secure Digital (SD) card, and a Flash Card, or other volatile solid-state storage devices.
[0034] It should be noted that the above-mentioned devices may include, but are not limited to, processors and memory, as will be understood by those skilled in the art.
[0035] For the working principle and process of the above embodiments, please refer to the description of Embodiment 1 of the present invention, which will not be repeated here.
[0036] Compared with existing technologies, this invention has the following significant advantages: Based on power system fault recording files, this invention sequentially completes the accurate determination of phase-to-phase grounding faults, identification of fault direction (forward or reverse), differentiation of fault nature (metallic or through transition resistance), and qualitative judgment of fault location. This overcomes the limitation of existing technologies, which can only preliminarily identify fault categories, and achieves a systematic and comprehensive analysis of the core characteristics of phase-to-phase grounding faults. This invention integrates multi-dimensional electrical characteristics of three-phase voltage, current, and zero-sequence components to form judgment rules. From data extraction to judgment at each stage, the design revolves around the specific electrical characteristics of phase-to-phase grounding faults. It avoids misjudgment through multi-condition cross-validation and relies on the amplitude and phase characteristics of the fault phase and zero-sequence component to achieve accurate identification of fault direction, nature, and location, significantly improving the accuracy and reliability of phase-to-phase grounding fault diagnosis. Simultaneously, this invention provides relay protection professionals with comprehensive and accurate fault characteristic data, provides effective technical support for optimizing the operating logic of relay protection devices, enhances the rapid response capability of power system fault diagnosis, meets the actual needs of modern smart grids for accurate fault diagnosis and self-healing control, and ensures the safe and stable operation of the power system.
[0037] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.
Claims
1. A method for determining the nature of a fault in a phase-to-phase manner, characterized in that, include: Step S1: Obtain the fault recording file of the power system, and extract the three-phase voltage data, three-phase current data, zero-sequence voltage data and zero-sequence current data from the fault recording file. Step S2: Based on the extracted three-phase voltage data, three-phase current data, zero-sequence voltage data, and zero-sequence current data, determine whether a phase-to-phase grounding fault has occurred. If a phase-to-phase grounding fault is determined, then identify the faulty phase and the non-faulty phase. Step S3: Based on at least one of the following phase relationships, determine whether the fault direction of the phase-to-phase grounding fault is a positive or negative fault: the phase relationship between the fault phase current and the non-fault phase voltage, the phase relationship between the zero-sequence current and the non-fault phase voltage, and the phase relationship between the zero-sequence current and the zero-sequence voltage. Step S4: Based on the current amplitude relationship between the two faulted phases, the voltage amplitude relationship between the two faulted phases, the phase relationship between the zero-sequence voltage and the voltage of the non-faulted phase, and the phase relationship between the current of the non-faulted phase and the voltage of the non-faulted phase, determine whether the fault nature of the phase-to-phase grounding fault is a metallic grounding fault or a fault through a transition resistor. Step S5: Based on the amplitude and phase characteristics of the fault phase voltage, the amplitude characteristics of the fault phase current, and the amplitude and phase characteristics of the zero-sequence current, determine the fault location of the phase-to-phase grounding fault.
2. The method according to claim 1, characterized in that, In step S2, a phase-to-phase grounding fault is determined to have occurred when all of the following conditions are met simultaneously: Two of the three-phase voltages have decreased voltage amplitude, while the voltage amplitude and phase of the remaining phase remain unchanged, and a zero-sequence voltage appears. The amplitudes of the two phase currents corresponding to the voltage drop increase synchronously at the moment the voltage drops, and zero-sequence current appears. The current amplitude of the phase whose voltage amplitude did not decrease and whose phase did not change remained unchanged. At the same time, the two phases with decreased voltage and increased current are identified as faulty phases, while the phase with no change in voltage and current is identified as a non-faulty phase.
3. The method according to claim 1, characterized in that, In step S3, the phase-to-phase grounding fault is determined to be a positive-direction fault if any of the following conditions are met: The zero-sequence current leads the non-faulty phase voltage by 95°~110°, or the zero-sequence current leads the zero-sequence voltage by 95°~110°. The phase of the leading phase current in the two faulted phase currents leads the phase voltage of the non-faulted phase current by 150°~190°. The phase of the lagging phase current in the two faulted phase currents leads the phase voltage of the non-faulted phase by 10°~50°.
4. The method according to claim 3, characterized in that, In step S3, if any of the determination conditions for the positive direction fault are not met, the phase-to-phase fault is determined to be a reverse direction fault.
5. The method according to claim 1, characterized in that, In step S4, the phase-to-phase grounding fault is determined to be a fault via a transition resistor if any of the following conditions are met: The current amplitudes of the two faulty phases are not equal, and the current amplitude of the leading phase is greater than that of the lagging phase. The voltage amplitudes of the two faulty phases are not equal; The zero-sequence voltage is out of phase with the voltage of the non-faulty phase; The angle by which the current of the non-faulty phase lags behind the voltage of the non-faulty phase is less than 80°.
6. The method according to claim 5, characterized in that, In step S4, if any of the determination conditions for the fault via the transition resistor are not met, the phase-to-phase grounding fault is determined to be a metallic grounding fault.
7. The method according to claim 1, characterized in that, In step S5, the phase-to-phase grounding fault is determined to be a fault at the line exit when any of the following conditions are met: The voltage amplitude of the two faulty phases is zero or lower than the preset amplitude threshold, and the voltage phase of the two faulty phases is the same; The voltages of the two faulted phases are in phase with the zero-sequence current.
8. The method according to claim 1, characterized in that, In step S5, the larger the current amplitude of the two fault phases, the closer the distance between the fault point and the measurement point is; the larger the amplitude of the zero-sequence current, the closer the distance between the fault point and the measurement point is.
9. A device for determining the nature of a fault in a phase-to-phase manner, characterized in that, include: One or more processors; Memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, the one or more applications being configured to perform the relative fault nature determination method as described in any one of claims 1 to 8.
10. A computer program product, characterized in that, Includes computer instructions that instruct a computer device to perform operations corresponding to the fault nature determination as described in any one of claims 1 to 8.