Power electronic access line reliable fault traveling wave identification method based on source explanation competition and related device

Abstract

The application provides a power electronic access line reliable fault traveling wave identification method based on source explanation competition and a related device, and belongs to the field of power system fault detection. The method uses a fault point direct traveling wave source explanation model and a power electronic access point secondary disturbance source explanation model, accurately quantifies the fault point source explanation degree and the access point source explanation degree based on the comprehensive deviation of the theoretical and actual arrival time of the two types of transient sources, introduces the physical state constraint information of the power electronic access point, combines the dual source explanation degree for multi-dimensional source attribute discrimination, and discriminates the real source of the transient event through the physical competition mechanism of the dual source explanation ability, thereby solving the wave head misselection problem in the distribution network containing a large number of power electronic devices from the physical nature, avoiding the fault distance calculation deviation and fault section judgment error caused by the interference wave head misjudgment, and significantly improving the accuracy and operation reliability of the fault traveling wave identification, fault distance calculation and fault section positioning.

Description

Technical Field

[0001] This invention belongs to the field of power system fault detection technology, specifically relating to a reliable fault traveling wave identification method and related device for power electronic access lines based on source interpretation competition. Background Technology

[0002] Accurately and quickly determining the location of faults is crucial for ensuring the safe and stable operation of power systems. Fault traveling wave location technology, as an important fault location method, has wide applications in the field of power system fault detection. It is based on the propagation characteristics of high-frequency transient traveling waves generated at the moment of a fault in the transmission line, and calculates the fault distance or locates the fault section by analyzing parameters such as the traveling wave propagation time.

[0003] With the deepening of the construction of new power systems, various power electronic devices are being connected to the distribution network on a large scale, completely changing the transient characteristics after line faults. After a fault, power electronic devices will exhibit a series of dynamic control behaviors, such as rapid current limiting, blocking protection, low voltage ride-through, control mode switching, and phase-locked loop adjustment. These behaviors not only generate secondary transient disturbances at their connection points and propagate to both sides of the line, but also change the reflection, refraction, and injection characteristics of transient signals through interface filters and high-frequency equivalent impedances. As a result, the transient changes detected by the measuring points no longer all correspond to the traveling waves directly excited by the fault point.

[0004] Existing traveling wave ranging and wavefront selection methods are still based on the inherent assumption of a single traditional transient source. They cannot distinguish between the direct traveling wave at the fault point and the secondary disturbance generated by the control action of power electronic equipment from a physical perspective. In distribution networks containing a large number of power electronic equipment, wavefront misselection is very likely to occur, which in turn leads to deviations in fault distance calculation and incorrect fault section judgment, seriously affecting the accuracy and reliability of traveling wave ranging. Summary of the Invention

[0005] Therefore, it is necessary to provide a reliable fault traveling wave identification method and related device for power electronic access lines based on source interpretation competition to address the above-mentioned technical problems, so as to solve the problem that wavefront misselection is very easy to occur in distribution networks containing a large number of power electronic devices, which leads to the deviation of fault distance calculation and the error of fault section judgment.

[0006] In a first aspect, the present invention provides a method for reliable fault traveling wave identification in power electronic access lines based on source interpretation competition, comprising the following steps:

[0007] In response to undetermined transient events in power electronic access lines;

[0008] The direct traveling wave source interpretation model of the fault point is used to determine the explanatory power of the fault point source. The direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation. The first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0009] The explanatory power of the access point source is determined by using the secondary disturbance source interpretation model of the power electronic access point. The secondary disturbance source interpretation model of the power electronic access point is used to quantify the explanatory power of the access point source based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that the secondary disturbance of the power electronic access point arrives at each measuring point.

[0010] Obtain physical state constraint information of power electronic access points;

[0011] By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute is determined for the transient event to be judged, and the source attribute determination result is obtained.

[0012] By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

[0013] Furthermore, using the direct traveling wave source interpretation model of the fault point, the explanatory power of the fault point source is determined, including:

[0014] Based on the line topology data, a set of candidate fault locations is obtained;

[0015] For each candidate fault location in the candidate fault location set, the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measuring point is calculated using the fault point direct traveling wave source interpretation model, when the corresponding candidate fault location is used as the fault point source, so as to obtain the first comprehensive deviation of each candidate fault location.

[0016] The candidate fault location with the smallest first comprehensive deviation is selected as the optimal fault source interpretation location.

[0017] The comprehensive deviation value corresponding to the optimal fault source explanation location is quantified as the fault source explanation degree.

[0018] Furthermore, using the power electronic access point secondary disturbance source interpretation model, the access point source explanatory power is determined, including:

[0019] Based on the line topology data and the location data of power electronic access points, a set of power electronic access points is obtained;

[0020] For each access point in the power electronic access point set, the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measurement point is calculated using the power electronic access point secondary disturbance source interpretation model, when the corresponding access point is used as a secondary disturbance source, thus obtaining the second comprehensive deviation of each access point.

[0021] The candidate access point with the smallest second comprehensive deviation is selected as the optimal access point source interpretation location.

[0022] The comprehensive deviation value corresponding to the optimal access point source interpretation location is quantified as the access point source interpretation degree.

[0023] Furthermore, for both fault source and secondary disturbance source, the comprehensive deviation between the theoretical and actual arrival times of transient events at each measuring point is calculated, including:

[0024] Based on the source location and the traveling wave propagation parameters of the line, calculate the theoretical arrival time of the transient event from the source to each measuring point; obtain the actual arrival time of the transient event from the source to each measuring point.

[0025] Calculate the single-point time residual between the theoretical arrival time and the actual arrival time for each measuring point;

[0026] The sum of squares of the single-point time residuals of all measuring points is calculated to obtain the comprehensive deviation value corresponding to the source point.

[0027] Furthermore, the overall deviation value is quantified into the source explanatory power of the corresponding source point, including:

[0028] Divide the overall deviation value by the number of measuring points to obtain the normalized value of the overall deviation;

[0029] The exponential normalization method converts the normalized value of the composite deviation into the source explanatory power of the corresponding source point; the source explanatory power is negatively correlated with the composite deviation value.

[0030] Furthermore, the physical state constraint information includes boundary state transitions; the physical state constraint information of the power electronic access point is obtained, including:

[0031] Based on the calculation results of the secondary disturbance source interpretation model of the power electronic access point, the optimal access point source interpretation location and the corresponding optimal secondary disturbance source interpretation time are determined.

[0032] Obtain boundary state data within a preset time window before and after the optimal secondary disturbance source excitation time at the optimal access point source interpretation location;

[0033] The change in boundary state data before and after the optimal excitation time of the secondary disturbance source is calculated to obtain the boundary state transition quantity.

[0034] Furthermore, the physical state constraint information also includes the verifiability of the device state; obtaining the physical state constraint information of the power electronic access point includes:

[0035] Obtain the set of device status events within a preset time window before and after the optimal secondary disturbance source excitation time at the optimal access point source interpretation location;

[0036] The verifiability of the equipment state is quantified by the type weight of each event in the equipment state event set and the time matching degree with the excitation time of the best secondary disturbance source.

[0037] Furthermore, by combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, source attribute discrimination is performed on the transient event to be judged, and the source attribute discrimination results are obtained, including:

[0038] The access point source interpretability and physical state constraint information are fused to obtain the final interpretability of the access point source.

[0039] Compare the relative magnitudes of the fault point source explanatory power and the access point source final explanatory power;

[0040] The transient event attributes are determined based on the relative size and the preset source attribute discrimination threshold, and the source attribute discrimination result is obtained.

[0041] Furthermore, it also includes:

[0042] Based on the relative size and the preset source attribute discrimination threshold, the source attribute discrimination confidence is calculated; the higher the source attribute discrimination confidence, the higher the stability of the source attribute discrimination result.

[0043] Secondly, the present invention provides a power electronic access line reliable fault traveling wave identification device based on source interpretation competition, comprising:

[0044] The transient event response module is used to respond to transient events to be identified in power electronic access lines;

[0045] The fault point source interpretation quantification module is used to determine the fault point source explanatory power using the fault point direct traveling wave source interpretation model; the fault point direct traveling wave source interpretation model is used to quantify the fault point source explanatory power based on the first comprehensive deviation; the first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0046] The access point disturbance source interpretation quantification module is used to determine the access point source explanatory power using the power electronic access point secondary disturbance source interpretation model. The power electronic access point secondary disturbance source interpretation model is used to quantify the access point source explanatory power based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming the secondary disturbance of the power electronic access point arrives at each measuring point.

[0047] The physical constraint information acquisition module is used to acquire the physical state constraint information of the power electronic access point;

[0048] The transient source attribute discrimination module is used to combine the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information to perform source attribute discrimination on the transient event to be judged, and obtain the source attribute discrimination result;

[0049] The fault traveling wave result integration module is used to integrate the source attribute discrimination results and the corresponding source interpretation degree to obtain a reliable fault traveling wave identification result indicating the transient event to be discriminated.

[0050] Thirdly, the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0051] In response to undetermined transient events in power electronic access lines;

[0052] The direct traveling wave source interpretation model of the fault point is used to determine the explanatory power of the fault point source. The direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation. The first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0053] The explanatory power of the access point source is determined by using the secondary disturbance source interpretation model of the power electronic access point. The secondary disturbance source interpretation model of the power electronic access point is used to quantify the explanatory power of the access point source based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that the secondary disturbance of the power electronic access point arrives at each measuring point.

[0054] Obtain physical state constraint information of power electronic access points;

[0055] By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute is determined for the transient event to be judged, and the source attribute determination result is obtained.

[0056] By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

[0057] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, performs the following steps:

[0058] In response to undetermined transient events in power electronic access lines;

[0059] The direct traveling wave source interpretation model of the fault point is used to determine the explanatory power of the fault point source. The direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation. The first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0060] The explanatory power of the access point source is determined by using the secondary disturbance source interpretation model of the power electronic access point. The secondary disturbance source interpretation model of the power electronic access point is used to quantify the explanatory power of the access point source based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that the secondary disturbance of the power electronic access point arrives at each measuring point.

[0061] Obtain physical state constraint information of power electronic access points;

[0062] By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute is determined for the transient event to be judged, and the source attribute determination result is obtained.

[0063] By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

[0064] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0065] In response to undetermined transient events in power electronic access lines;

[0066] The direct traveling wave source interpretation model of the fault point is used to determine the explanatory power of the fault point source. The direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation. The first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0067] The explanatory power of the access point source is determined by using the secondary disturbance source interpretation model of the power electronic access point. The secondary disturbance source interpretation model of the power electronic access point is used to quantify the explanatory power of the access point source based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that the secondary disturbance of the power electronic access point arrives at each measuring point.

[0068] Obtain physical state constraint information of power electronic access points;

[0069] By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute is determined for the transient event to be judged, and the source attribute determination result is obtained.

[0070] By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

[0071] In summary, this invention provides a reliable fault traveling wave identification method and related device for power electronic access lines based on source interpretation competition. This method utilizes a direct traveling wave source interpretation model at the fault point and a secondary disturbance source interpretation model at the power electronic access point. Based on the comprehensive deviation between the measurement point theory and actual arrival time corresponding to the two types of transient sources, it accurately quantifies the source interpretation degree of the fault point and the access point, achieving a characterization of the reliability of the line fault-induced transient and the power electronic access point secondary disturbance transient from the perspective of time-series propagation laws. Simultaneously, this invention introduces physical state constraint information of the power electronic access point and combines dual-source interpretation for multi-dimensional source attribute discrimination. Through the physical competition mechanism of dual-source interpretation capabilities, it identifies the true source of transient events, effectively eliminating interference caused by secondary disturbances of power electronic equipment, and accurately screening reliable fault traveling waves. This fundamentally solves the problem of wavefront misselection in distribution networks containing a large number of power electronic equipment, avoiding problems such as fault distance calculation deviation and fault section judgment errors caused by misjudgment of interference wavefronts. It significantly improves the accuracy and operational reliability of fault traveling wave identification, fault distance measurement, and fault section location in complex power electronic distribution network scenarios. Attached Figure Description

[0072] 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.

[0073] Figure 1 This is a flowchart illustrating a reliable fault traveling wave identification method for power electronic access lines based on source interpretation competition, as described in one embodiment of the present invention.

[0074] Figure 2 This is a flowchart of a preferred embodiment of the traveling wave identification method for reliable faults in power electronic access lines based on source interpretation competition according to the present invention.

[0075] Figure 3 This is a block diagram of a power electronic access line reliable fault traveling wave identification device based on source interpretation competition in one embodiment of the present invention;

[0076] Figure 4 This is a block diagram of a computer device according to one embodiment of the present invention. Detailed Implementation

[0077] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0078] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0079] The background technology of this invention will be further introduced below.

[0080] Power system fault traveling wave location technology relies on the propagation time difference, reflection time difference, and arrival time correlation characteristics of high-frequency transient traveling waves generated at the moment of a fault in the line to calculate fault distance and locate fault sections. It is one of the core technologies for power grid fault diagnosis. The logic of traditional traveling wave location technology is that the fault point is the sole excitation source of the transient traveling wave. The fault traveling wave propagates bidirectionally along the line from the fault point, and after reflection at line ends, busbars, branch nodes, etc., it is captured by traveling wave acquisition devices deployed along the line. Current technologies generally capture the traveling wave front through fixed threshold discrimination, wavelet transform, S-transform, modulus maxima detection, transient energy mutation identification, and first wave arrival time extraction. Combined with line length, traveling wave propagation speed, and measurement point time difference, it achieves single-end, double-end, or multi-end fault location. This type of traditional method has a mature architecture and high computational efficiency, and it has good application effects and location accuracy in traditional distribution network lines with simple line structures, significant fault traveling wave characteristics, clear wavefront mutations, and a single transient excitation source.

[0081] With the large-scale grid connection of various power electronic devices such as photovoltaic inverters, energy storage converters, flexible interconnection devices, SVG, power electronic transformers, DC charging piles, and frequency conversion loads, the transient physical processes of distribution network faults have undergone fundamental changes, posing significant challenges to traditional traveling wave ranging technology. On the one hand, power electronic devices possess characteristics such as rapid current limiting, blocking protection, low voltage ride-through, phase-locked loop dynamic adjustment, control mode switching, PWM modulation fluctuations, and dynamic response of DC bus voltage. After a line fault occurs, the transient signals collected by the measuring points not only include the original fault traveling wave directly excited by the fault point, but also the secondary transient disturbances derived from the control actions of the power electronic access point. On the other hand, the interface filters, dynamic control states, and high-frequency equivalent impedance of power electronic devices will change the traveling wave reflection, refraction, and signal injection characteristics at the access point, resulting in transient change signals detected by the measuring points not all being triggered by line faults. The closest existing technology to this invention is the "candidate traveling wave extraction plus multi-feature reliable screening" method. This type of method first extracts candidate wavefronts and transient segments through filtering, modulus transformation, time-frequency analysis, etc., and then performs comprehensive scoring and screening based on waveform features such as high-frequency energy ratio, wavefront steepness, pulse width, and propagation consistency at multiple measurement points. To a certain extent, it can avoid noise and interference from normal operating conditions. However, this type of method is essentially a waveform feature screening logic, without delving into the physical source of transient signals, without constructing a competitive discrimination mechanism between fault sources and power electronic secondary disturbance sources, and without combining the operating state constraints of power electronic equipment for discrimination. Therefore, it cannot effectively distinguish between fault-native traveling waves and power electronic secondary disturbance signals.

[0082] Existing traveling wave identification and ranging technologies suffer from several inherent technical defects, making them ill-suited for the fault diagnosis needs of power electronic distribution networks. Firstly, existing technologies generally assume that transient events are triggered by line faults, relying on this single-source assumption for the discrimination logic. This makes it impossible to physically distinguish between the traveling wave directly originating from the fault point and the secondary disturbances generated by the control actions of power electronic equipment, easily misidentifying secondary disturbance signals as fault traveling waves. Secondly, existing screening methods rely solely on waveform appearance characteristics and conventional propagation consistency for discrimination, failing to incorporate physical mechanism information such as boundary state transitions at power electronic access points, equipment action records, and control state changes. This lack of targeted physical constraints makes it impossible to verify the actual feasibility of secondary disturbance generation. Thirdly, in scenarios with superimposed multi-source transient signals, existing technologies are prone to mistakenly selecting the secondary disturbance wavefront from power electronics for fault location, completely undermining the source point assumption of the traveling wave ranging algorithm. This ultimately leads to problems such as fault distance calculation errors, misjudgments of fault sections, and unstable location results, significantly reducing the accuracy and reliability of fault location in power electronic distribution networks. To address the shortcomings of the existing technologies, this invention aims to provide a reliable fault traveling wave identification method and related apparatus for power electronic access lines based on source interpretation competition. It abandons the traditional single waveform feature screening mode, constructs a dual-competitive interpretation model of the direct traveling wave source at the fault point and the secondary disturbance source at the power electronic access point, and combines equipment physical state constraint information to complete transient source attribute discrimination, accurately screening reliable fault traveling waves. The following describes various embodiments of this invention.

[0083] Please see Figure 1 This invention first provides a method for identifying reliable fault traveling waves in power electronic access lines based on source interpretation contention, comprising the following steps:

[0084] S101: A pending transient event in response to a power electronic access line.

[0085] Among them, power electronic access lines refer to distribution lines, microgrid lines, new energy aggregation lines, AC / DC hybrid lines, or flexible interconnection distribution lines that include photovoltaic inverters, energy storage converters, flexible interconnection devices, flexible voltage regulation devices, SVG, STATCOM, power electronic transformers, DC charging piles, frequency conversion loads, or other power electronic equipment connected to the line; transient events to be judged refer to transient signal events with abrupt change characteristics collected by the measuring point when a short circuit fault, single-phase ground fault, phase-to-phase fault, high-resistance ground fault, or other fault disturbance occurs on the line, including fault traveling waves directly excited by the fault point and secondary transient disturbances generated by the power electronic access point.

[0086] It should be noted that several measuring points are determined on the power electronic access line. Each measuring point acquires voltage and current signals in real time. When the rate of change or amplitude of the signal exceeds a preset threshold, a transient event is triggered for recording. Transient events can be provided by a traveling wave acquisition terminal, a protection start-up module, a waveform recording device, an external wavefront detection module, or a manual annotation module.

[0087] S102: Determine the explanatory power of the fault point source using the direct traveling wave source interpretation model of the fault point; the direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation; the first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that is triggered by the line fault point and arrives at each measuring point.

[0088] Among them, the fault point direct traveling wave source interpretation model refers to the mathematical model used to evaluate the rationality of the assumption that "the transient event to be determined is caused by the traveling wave excited by the line fault point"; the fault point source interpretation degree refers to the credibility of the assumption, and the higher the value, the more reasonable the assumption is; the first comprehensive deviation refers to the comprehensive difference between the actual arrival time of the traveling wave detected by each measuring point and the theoretical arrival time calculated based on the line parameters when the transient event is assumed to be excited by a certain line fault point.

[0089] It should be noted that the propagation speed of traveling waves in power lines is close to the speed of light, and the time it takes for them to arrive at different measurement points is proportional to the distance between the source point and the measurement point.

[0090] Optionally, this step involves calling a pre-built fault point direct traveling wave source interpretation model, inputting the arrival time data of the traveling waves at each measurement point of the transient event to be identified and the line topology parameters, and outputting the corresponding fault point source interpretation degree.

[0091] S103: Determine the explanatory power of the access point source using the power electronic access point secondary disturbance source interpretation model; the power electronic access point secondary disturbance source interpretation model is used to quantify the explanatory power of the access point source based on the second comprehensive deviation; the second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming the secondary disturbance of the power electronic access point arrives at each measuring point.

[0092] Among them, the power electronic access point secondary disturbance source interpretation model is a mathematical model used to evaluate the rationality of the hypothesis that "the transient event to be determined is caused by the traveling wave generated by the secondary disturbance of the power electronic access point"; the access point source interpretation degree refers to the credibility of the hypothesis, and the higher the value, the more reasonable the hypothesis is; the second comprehensive deviation refers to the comprehensive difference between the actual arrival time of the traveling wave detected by each measuring point and the theoretical arrival time calculated based on the line parameters when the transient event is assumed to be excited by the secondary disturbance of a certain power electronic access point.

[0093] It should be noted that the switching, tripping, and fault ride-through processes of power electronic devices generate high-frequency transient traveling waves. These traveling waves are highly similar in waveform characteristics to those generated by line faults, which can easily lead to malfunctions of traditional traveling wave protection.

[0094] Optionally, this step involves calling a pre-built secondary disturbance source interpretation model for power electronic access points, inputting the arrival time data of traveling waves at each measurement point of the transient event to be identified, line topology parameters, and power electronic access point location data, and outputting the corresponding access point source interpretation degree.

[0095] S104: Obtain the physical state constraint information of the power electronic access point.

[0096] Among them, physical state constraint information refers to objective data that can reflect the actual operating state of the power electronic access point before and after the occurrence of a transient event, and is used to verify the physical feasibility of the hypothesis that "the transient event is caused by a secondary disturbance of the access point".

[0097] It should be noted that the operating status of power electronic devices can be monitored in real time through their own control systems, SCADA systems, PMU devices, etc. The acquired status data includes switching status, output voltage and current, power, temperature, etc., which are important bases for judging whether the device has been disturbed.

[0098] Optionally, this step involves obtaining operating status data within a preset time range before and after the occurrence of a transient event from the status monitoring system of the power electronic access point, and extracting feature information that reflects the changes in the device status as physical state constraint information.

[0099] S105: Combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, perform source attribute discrimination on the transient event to be judged, and obtain the source attribute discrimination result.

[0100] Among them, source attribute discrimination refers to the process of determining whether the source of the transient event to be judged is a line fault point or a secondary disturbance at the power electronic access point; the source attribute discrimination result refers to the final judgment on the source of the transient event, including two types: "fault traveling wave" and "secondary disturbance traveling wave".

[0101] Optionally, this step combines physical state constraint information to correct the access point source interpretability, obtains the final access point source interpretability, and then compares the fault point source interpretability with the final access point source interpretability to determine the source attribute of the transient event according to the preset discrimination rules.

[0102] S106: Integrate the source attribute discrimination results and the corresponding source interpretation degree to obtain the reliable fault traveling wave identification results that indicate the transient events to be discriminated.

[0103] Among them, the credible fault traveling wave identification result refers to the comprehensive identification result that includes the transient event source attributes and the corresponding credibility level. It can not only indicate whether the transient event is a fault traveling wave, but also give the credibility level of the judgment.

[0104] It should be noted that in power system protection applications, the reliability of the identification results is an important basis for determining whether or not protection actions are taken. Highly reliable identification results can directly trigger protection actions, while lowly reliable identification results require further verification or conservative measures.

[0105] Optionally, this step combines the source attribute discrimination result (fault traveling wave or secondary disturbance traveling wave) with the corresponding highest source interpretability to generate a reliable fault traveling wave identification result that includes at least two fields: source attribute and confidence level.

[0106] The method provided in this embodiment utilizes a direct traveling wave source interpretation model at the fault point and a secondary disturbance source interpretation model at the power electronic access point. Based on the comprehensive deviation between the measurement point theory and the actual arrival time corresponding to the two types of transient sources, it accurately quantifies the source interpretation degree of the fault point and the source interpretation degree of the access point. This enables the characterization of the credibility of the transient state triggered by the line fault and the transient state of the secondary disturbance at the power electronic access point from the perspective of time-series propagation law. At the same time, this invention introduces physical state constraint information of the power electronic access point and performs multi-dimensional source attribute discrimination in combination with the dual-source interpretation degree. Through the physical competition mechanism of dual-source interpretation capability, the true source of the transient event is determined, effectively eliminating the interference caused by the secondary disturbance of the power electronic equipment, and accurately screening out the credible fault traveling wave. This fundamentally solves the problem of wavefront misselection in distribution networks with a large number of power electronic equipment, avoids the problems of fault distance calculation deviation and fault section judgment error caused by the misjudgment of interference wavefronts, and significantly improves the accuracy and operational reliability of fault traveling wave identification, fault distance measurement and fault section location in complex power electronic distribution network scenarios.

[0107] In an exemplary embodiment, the fault point source interpretability is determined using a direct traveling wave source interpretation model, including:

[0108] S201: Based on the line topology data, obtain a set of candidate fault locations.

[0109] Among them, the line topology data refers to the dataset describing the node connection relationship, line length, line type and other information of the power line; the candidate fault location set refers to the set of line locations that may be faulted in advance, and each element in the set corresponds to a specific location on the line.

[0110] For example, the topology data of the line to be identified is first obtained. ,in, Represents the route topology diagram. Represents the set of line nodes. Denotes the set of line branches, for the th Each line segment is defined as having a length of [missing information]. The unit is meters, and its traveling wave propagation speed is... The unit is meters per second. Number the segments of the line; if the line has inductance per unit length and capacitance per unit length Given that, the propagation speed can be calculated using the following formula:

[0111] ;

[0112] in, For the first Inductance per unit length of each line segment For the first The capacitance per unit length of each line segment. If the line parameters are unknown or have significant deviations, they can also be obtained through on-site calibration, historical disturbance data, simulation identification, or correction using line parameter ledgers. .

[0113] Then, according to the preset candidate position, the distance from the walking distance is... The entire line is discretized into multiple continuous segments, with the midpoint of each segment serving as a candidate fault location. All candidate fault locations form a set of candidate fault locations. ,in, Represents the set of candidate fault locations. Indicates the first One candidate fault location, This indicates the number of candidate positions.

[0114] Preferably, for overhead lines, for For cable lines, for The candidate position is preferably the distance from the walking distance. More preferably, . The smaller the value, the higher the resolution of the fault source interpretation location, but the greater the computational load; The larger the value, the faster the calculation speed, but it may reduce the ability to distinguish source locations.

[0115] S202: For each candidate fault location in the candidate fault location set, the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measuring point is calculated using the fault point direct traveling wave source interpretation model, when the corresponding candidate fault location is used as the fault point source, to obtain the first comprehensive deviation of each candidate fault location.

[0116] The theoretical arrival time refers to the time required for a traveling wave to propagate from a candidate fault location to a measuring point when the transient event is assumed to be triggered by that location; the actual arrival time refers to the time when the transient traveling wave is actually detected at that measuring point.

[0117] It should be noted that for each candidate fault location, the theoretical propagation time from that location to each effective measuring point is calculated, and the theoretical arrival time is obtained by combining the assumed fault source excitation time; the theoretical arrival time is compared with the actual arrival time, and the comprehensive value of the time deviation of all measuring points is calculated to obtain the first comprehensive deviation corresponding to the candidate location.

[0118] S203: Select the candidate fault location with the smallest first comprehensive deviation as the optimal fault source interpretation location.

[0119] Among them, the optimal fault source interpretation location refers to the location with the strongest ability to interpret the propagation time sequence of transient events among all candidate fault locations, that is, the candidate location with the smallest first comprehensive deviation.

[0120] It should be noted that by iterating through all candidate fault locations and finding the minimum value of the first comprehensive deviation, the candidate fault location corresponding to the minimum value is the optimal fault source interpretation location, and the minimum first comprehensive deviation value corresponding to this location is recorded.

[0121] S204: Quantify the comprehensive deviation value corresponding to the optimal fault source explanation location into the fault source explanation degree.

[0122] Among them, the fault source explanatory power refers to the quantitative value obtained after converting the first comprehensive bias, which is used to represent the degree to which the fault source model explains transient events.

[0123] For example, the minimum first comprehensive deviation corresponding to the optimal fault source explanation location is normalized, and then converted into a quantized value in the range of 0 to 1 through a preset conversion function to obtain the fault source explanation degree; the smaller the comprehensive deviation value, the higher the corresponding fault source explanation degree.

[0124] This embodiment discretizes the line into a set of candidate fault locations, calculates the first comprehensive deviation of each candidate location, selects the best interpretation location, and quantifies its comprehensive deviation as the fault source explanatory power, thereby realizing the quantification of fault source explanatory power based on propagation time sequence characteristics.

[0125] In an exemplary embodiment, the source explanatory power of the access point is determined using a power electronic access point secondary disturbance source explanation model, including:

[0126] S301: Based on the line topology data and the location data of the power electronic access points, a set of power electronic access points is obtained.

[0127] Among them, power electronic access point location data refers to the specific node location information of each power electronic device in the line topology; the power electronic access point set refers to the set of all power electronic device access points on the line.

[0128] For example, let the set of power electronic access points be... ,in, Represents the set of power electronic access points. Indicates the first One power electronics access point, Indicates the number of power electronic access points. .

[0129] S302: For each access point in the power electronic access point set, the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measurement point is calculated using the power electronic access point secondary disturbance source interpretation model, when the corresponding access point is used as a secondary disturbance source, to obtain the second comprehensive deviation of each access point.

[0130] It should be noted that for each power electronic access point, the theoretical propagation time from the access point to each effective measurement point is calculated, and the theoretical arrival time is obtained by combining the assumed time of secondary disturbance. The theoretical arrival time is compared with the actual arrival time, and the comprehensive value of the time deviation of all measurement points is calculated to obtain the second comprehensive deviation corresponding to the access point.

[0131] S303: Select the candidate access point with the smallest second comprehensive deviation as the optimal access point source interpretation location.

[0132] Among them, the optimal access point source interpretation location refers to the access point with the strongest ability to interpret the propagation time sequence of transient events among all power electronic access points, that is, the access point with the smallest second comprehensive deviation.

[0133] It should be noted that by iterating through all the second comprehensive deviations corresponding to the power electronic access points, the minimum value is found. The power electronic access point corresponding to this minimum value is the optimal access point source interpretation location, and the minimum second comprehensive deviation value corresponding to this access point is recorded.

[0134] S304: Quantify the comprehensive deviation value corresponding to the optimal access point source interpretation location as the access point source interpretation degree.

[0135] The access point source explanatory power refers to the quantified value obtained after converting the second comprehensive bias, which is used to represent the degree of explanation of transient events by the access point source model from the perspective of propagation time sequence only.

[0136] It should be noted that the minimum second comprehensive deviation corresponding to the optimal access point source interpretation location is normalized, and then converted into a quantized value in the range of 0 to 1 using the same conversion function as the fault point source interpretation degree, thus obtaining the access point source interpretation degree; the smaller the comprehensive deviation value, the higher the corresponding access point source interpretation degree.

[0137] This embodiment calculates the second comprehensive deviation by traversing all power electronic access points, selects the best interpretable access point, and quantifies its comprehensive deviation as the access point source interpretability. This achieves accurate quantification of the access point source interpretability based on propagation time sequence characteristics, which, together with the fault point source interpretability, forms the basis for source interpretability competition.

[0138] In an exemplary embodiment, for both the fault source and the secondary disturbance source, the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measuring point is calculated, including:

[0139] S401: Based on the source location and the traveling wave propagation parameters of the line, calculate the theoretical arrival time of the transient event from the source to each measuring point; obtain the actual arrival time of the transient event from the source to each measuring point.

[0140] Among them, the source location refers to the location of the candidate fault point or the power electronic access point; the line traveling wave propagation parameters refer to the length of each segment of the line and the traveling wave propagation speed; the theoretical arrival time refers to the sum of the source point excitation time and the theoretical propagation time from the source point to the measuring point; and the actual arrival time refers to the actual arrival time of the transient event at each measuring point.

[0141] For example, let the set of line measurement points be... ,in, Represents the set of measurement points along the line. Indicates the first One measuring point, Indicates the number of measurement points. Preferably, When the line structure is complex, has many branches, or has many power electronic access points, it is preferred to... To improve the reliability of source attribute identification.

[0142] Define any two points on the line topology and The propagation time between them is:

[0143] ;

[0144] in, Indicates from position Arrive at the location The theoretical propagation time, Indicates from arrive The set of route segments traversed Indicates the first The length of each line segment Indicates the first The propagation speed of each line segment. If and If there are multiple reachable paths, the effective propagation path should be determined based on the actual switching status of the line, the operating mode, the protected section, or the shortest electrical propagation path.

[0145] Let the set of arrival times of a certain transient event to be judged at the effective measurement points be:

[0146] ;

[0147] in, This represents the set of arrival times of the transient events to be determined. This indicates that the transient event has reached a valid measurement point. The moment; This indicates the number of valid measurement points that detected the transient event.

[0148] Preferably, the number of effective measurement points is not less than 2; when the number of effective measurement points is 1, it is difficult to distinguish between the fault source and the power electronic access point source based on the arrival time of a single measurement point. In this case, the low confidence source attribute result can be output, or the equipment status information can be combined for auxiliary judgment.

[0149] S402: Calculate the single-point time residual between the theoretical arrival time and the actual arrival time of each measuring point.

[0150] Among them, the single-point time residual refers to the difference between the actual arrival time and the theoretical arrival time of a transient event at a single measuring point.

[0151] For example, in the direct traveling wave source interpretation model of the fault point, if the transient event to be determined is a traveling wave directly triggered by the line fault point, then there should be a certain fault location. and the triggering time of the fault source The arrival times of this transient event at each measuring point satisfy the following:

[0152] ;

[0153] in, For transient events arriving at the measuring point The actual moment, The excitation time of the direct traveling wave source at the fault point. Candidate fault location, Candidate Fault Points to the measuring point The theoretical propagation time, For measuring points Single-point time residual under the fault source model.

[0154] To ensure that a single-point residual corresponds to the subsequent population residual, the following definition is used:

[0155] ;

[0156] in, Indicates when the candidate fault location is The fault source is triggered at the following time. At that time, the first The deviation between the actual arrival time and the theoretical arrival time of each measuring point is the single-point time residual calculated based on the faulty power source.

[0157] For the interpretation model of secondary disturbance sources at power electronic access points, if the transient event to be determined is not directly triggered by the fault point, but is a secondary disturbance generated by a certain power electronic access point, then there should exist such a power electronic access point. and the time of the second disturbance The arrival times of this transient event at each measuring point satisfy the following:

[0158] ;

[0159] in, For transient events arriving at the measuring point The actual moment; The time when the secondary disturbance is generated at the power electronic access point; For the first One power electronic access point; Access point to the measuring point The theoretical propagation time; For measuring points At the access point Single-point time residual under the secondary disturbance source model.

[0160] To ensure that a single-point residual corresponds to the subsequent population residual, the following definition is used:

[0161] ;

[0162] in, This indicates that when the secondary disturbance source is the access point The time when the second disturbance is emitted is At that time, the first The deviation between the actual arrival time and the theoretical arrival time of each measurement point is the single-point time residual calculated based on the secondary disturbance source.

[0163] S403: Perform a sum of squares on the single-point time residuals of all measuring points to obtain the comprehensive deviation value corresponding to the source point.

[0164] Among them, the comprehensive deviation value refers to the minimum value of the sum of squares of the single-point time residuals of all valid measurement points, which is used to quantify the overall interpretation error of the source point model for the propagation time sequence of transient events.

[0165] For example, in a direct traveling wave source interpretation model for a fault point, for any candidate fault location... The overall interpretation residual of its fault source is defined as:

[0166] ;

[0167] Right now:

[0168] ;

[0169] in, Indicates the location of the candidate fault. The minimum value of the sum of squares of the time residuals at all valid measurement points; It represents the overall interpretation error of the transient event by the candidate fault location.

[0170] Because the above formula relates to The quadratic function has the optimal fault source activation time as:

[0171] ;

[0172] in: Indicates when the candidate fault location is The estimated fault source excitation time.

[0173] Will Substitution This yields the minimum overall interpretation residual at the candidate location, which is the comprehensive deviation value corresponding to the fault source.

[0174] Further, take the minimum value among all candidate fault locations:

[0175] ;

[0176] The corresponding optimal fault source interpretation location is:

[0177] ;

[0178] The corresponding optimal fault source activation time is:

[0179] ;

[0180] in, The minimum global interpretation residual of the direct traveling wave source model at the fault point for this transient event; Explain the location of the optimal fault source; This is the optimal time to explain the source of the fault.

[0181] The above method can determine whether the transient event can be uniformly explained by a single fault point on the line. If a candidate location exists... This ensures that the arrival times of different measuring points can all be derived from the same source time. and transmission time A good match indicates that the transient event conforms to the physical propagation law of "direct traveling wave source at the fault point". Through This explanatory power can be quantified. The smaller the value, the more complete the explanation of the fault source.

[0182] For the interpretation model of secondary disturbance sources at power electronic access points, for any power electronic access point The global interpretation residual of its secondary disturbance source is defined as:

[0183] ;

[0184] Right now:

[0185] ;

[0186] in, Indicates access point When used as a secondary disturbance source, the minimum value of the sum of squares of the single-point time residuals of all effective measurement points; It is the overall interpretation error of the access point for the transient event, that is, the comprehensive deviation source corresponding to the secondary disturbance source.

[0187] Because the above formula relates to Given a quadratic function, the optimal time for issuing the quadratic perturbation is:

[0188] ;

[0189] in, Indicates when the access point The estimated time of the secondary disturbance when used as a secondary disturbance source.

[0190] Will Substitution We obtain the minimum global interpretation residual when the access point is used as a secondary disturbance source.

[0191] Further, take the minimum value among all power electronic access points:

[0192] ;

[0193] The corresponding optimal power electronics access point is:

[0194] ;

[0195] If the optimal access point is The corresponding time of the second disturbance is:

[0196] ;

[0197] in, This represents the minimum global interpretation residual of the power electronic access point secondary disturbance source model for this transient event; Explain the location of the optimal access point source; This is the optimal time to interpret the secondary disturbance source.

[0198] The above method can determine whether the transient event can be uniformly explained by a certain known power electronic access point. If a certain access point... When used as a source, the arrival times of all measuring points can be determined by the same secondary perturbation emission time. and transmission time A good match indicates that the transient event exhibits propagation characteristics of a "secondary disturbance source at the power electronics access point." Through... It can quantify the source interpretation capability of access points. The smaller the value, the more complete the source interpretation of the access point.

[0199] This embodiment quantifies the interpretation error of the source point model by calculating the single-point time residual and performing a sum of squares operation.

[0200] In an exemplary embodiment, quantifying the comprehensive deviation value into the source explanatory power of the corresponding source point includes:

[0201] S501: Divide the overall deviation value by the number of measuring points to obtain the normalized value of the overall deviation.

[0202] The normalized value of the overall deviation refers to the interpreted residual per unit of measurement point obtained by dividing the overall deviation value by the number of effective measurement points. It is used to eliminate the influence of the number of measurement points on the overall deviation value.

[0203] For example, due to and The units are all time squared, and are related to the number of valid measurement points. Therefore, normalization is performed first.

[0204] Define the normalized fault source residual as:

[0205] ;

[0206] Define the normalized power electronics access point source residual as:

[0207] ;

[0208] in, Interpret the residuals for fault point sources in the sense of a unit measurement point; The residuals are explained for power electronic access point sources in the sense of unit measurement points.

[0209] S502: Exponential normalization method, which converts the normalized value of the composite deviation into the source explanatory power of the corresponding source point; the source explanatory power is negatively correlated with the composite deviation value.

[0210] Among them, exponential normalization refers to the method of converting the normalized value of the comprehensive deviation into a quantitative value in the range of 0 to 1 using an exponential function; source explanatory power refers to the quantitative value representing the degree of explanation of the transient event by the source point model, with a value range of 0 to 1.

[0211] For example, the residual scaling parameter is defined as follows: , The allowable overall time error is mainly determined by the sampling interval, measurement point synchronization error, line parameter error, and transient arrival time detection error.

[0212] Preferably, More preferably, When the sampling frequency is high, the synchronization accuracy of the measurement points is high, and the line parameters are accurate, A smaller value can be taken; when the power distribution line parameters are uncertain, the time synchronization error of the measuring point is large, or the detection deviation of the transient arrival time is large, A larger value can be taken.

[0213] Define the basic explanation strength of the fault point source:

[0214] ;

[0215] Define the fundamental interpretation strength of power electronic access point sources:

[0216] ;

[0217] in: This indicates the extent to which the transient event conforms to the direct traveling wave source model of the fault point only from the perspective of propagation timing; This indicates the extent to which the transient event conforms to the power electronic access point secondary disturbance source model from the perspective of propagation timing alone.

[0218] and The range of values ​​is The smaller the residual, the closer the underlying interpretation strength is to 1; the larger the residual, the closer the underlying interpretation strength is to 0.

[0219] It should be noted that, Simply stating that the "propagation timeline resembles an access point source" is insufficient to prove that the transient event is a power electronic secondary disturbance. Therefore, further investigation is needed, combining access point boundary state transitions and device state verifiability. Apply constraints.

[0220] Through the above quantification process, and Transform from "time square dimension residual" to The interpretation intensity within the range allows for comparison of fault source models and power electronic access point source models at the same scale. Due to differences in sampling frequency, synchronization error, and line parameter errors at different engineering sites, a residual scaling parameter is introduced. This can improve the method's adaptability to different field conditions.

[0221] This embodiment eliminates the influence of the number of measurement points through normalization, and then converts the comprehensive deviation value into the source explanatory power in the range of 0 to 1 through exponential normalization, realizing a quantitative comparison of the explanatory power of the two types of source models on the same scale.

[0222] In an exemplary embodiment, the physical state constraint information includes boundary state transitions; obtaining the physical state constraint information of the power electronic access point includes:

[0223] S601: Based on the calculation results of the secondary disturbance source interpretation model of the power electronic access point, determine the optimal access point source interpretation location and the corresponding optimal secondary disturbance source interpretation time.

[0224] Among them, the optimal access point source interpretation location refers to the power electronic access point with the smallest second comprehensive deviation; the optimal secondary disturbance source interpretation time refers to the optimal secondary disturbance emission time corresponding to the optimal access point source interpretation location.

[0225] S602: Obtain boundary state data of the optimal access point source interpretation location within a preset time window before and after the optimal secondary disturbance source excitation time.

[0226] Among them, boundary state data refers to state information that can reflect the boundary characteristics of the power electronics access point; the preset time window refers to the time interval centered on the optimal excitation time of the secondary disturbance source, which is used to observe the changes in the boundary state.

[0227] It should be noted that, based solely on The magnitude of the disturbance is too large to be directly attributed to a power electronic secondary disturbance. This is because while the propagation timeline of an event at a particular access point may explain the event, this does not necessarily mean that the access point physically generated a secondary disturbance. Therefore, further determination of the optimal access point is needed. At the time of the second perturbation explanation Has a change in the boundary state occurred nearby?

[0228] For example, define the best access point exist The boundary states before and after are , express Previous boundary states, express Subsequent boundary states. Boundary states can be determined by at least one of the following: normal grid connection state, current limiting state, lockout state, low voltage ride-through state, control mode switching state, PWM modulation state, grid connection switch state, filter switching state, DC bus abnormal state, and AC side current saturation state.

[0229] Let the boundary state observation time window be... Then they can be respectively in and Internal determination and .

[0230] Preferably More preferably, When the device status recording resolution is high, A smaller value can be chosen; when the device status record resolution is low or the control action is slow, A larger value can be taken.

[0231] Define the mapping function from the boundary state to the high-frequency equivalent reflection coefficient as follows: .

[0232] Then we have:

[0233] ;

[0234] ;

[0235] in, The high-frequency equivalent reflection coefficient of the optimal access point under the boundary state before disturbance; The high-frequency equivalent reflection coefficient of the optimal access point under the boundary state after disturbance is represented by the two, which together constitute the boundary state data.

[0236] In a preferred embodiment, if the boundary state The high-frequency equivalent impedance is The line surge impedance at the access point is Then the mapping function can be expressed as:

[0237] ;

[0238] in, For the optimal access point in the boundary state High-frequency equivalent impedance; The wave impedance of the branch where the optimal access point is located; This represents the high-frequency equivalent reflection coefficient corresponding to the boundary state.

[0239] If it is difficult to accurately obtain the high-frequency equivalent impedance in actual engineering, a lookup table relationship between the boundary state and the reflection coefficient can be established through equipment type, control status, manufacturer parameters, historical disturbance records, or on-site calibration. For example, normal grid connection, current limiting, blocking, low voltage ride-through, control saturation, and filter switching can be mapped to different reflection coefficient levels.

[0240] S603: Calculate the change in boundary state data before and after the optimal excitation time of the secondary disturbance source to obtain the boundary state transition.

[0241] Among them, the boundary state transition quantity refers to the quantitative value of the degree of change of the boundary state of the optimal access point before and after the second disturbance interpretation time.

[0242] For example, define boundary state transitions:

[0243] ;

[0244] in, This indicates the degree of boundary state change of the optimal power electronics access point near the time of the secondary source interpretation.

[0245] Since the reflection coefficient usually satisfies:

[0246] ;

[0247] ;

[0248] therefore:

[0249] ;

[0250] To convert the boundary transition into Constraint factors within the range, defined as:

[0251] ;

[0252] in, The confidence factor for boundary transitions; The boundary transition scale parameter.

[0253] Preferably, More preferably, .like If it is larger, then A value close to 1 indicates that the access point possesses the boundary change conditions to generate a secondary disturbance; if Smaller, then A value close to 0 indicates that even if the propagation timing is well matched, there is a lack of physical basis for the generation of secondary disturbances in power electronics.

[0254] This embodiment obtains the boundary state data of the optimal access point before and after the secondary disturbance interpretation time, maps it to the high-frequency equivalent reflection coefficient and calculates the change, and obtains the boundary state transition amount. This provides a physical boundary condition basis for the correction of the access point source interpretation degree, and can effectively eliminate false secondary disturbance interpretations that match the propagation time sequence but have no physical boundary changes.

[0255] In one exemplary embodiment, the physical state constraint information further includes device state verifiability; obtaining the physical state constraint information of the power electronic access point includes:

[0256] S701: Obtain the set of device status events within a preset time window before and after the optimal secondary disturbance source excitation time at the optimal access point source interpretation location.

[0257] Among them, the set of equipment status events refers to the set of all equipment status events that may cause secondary disturbances that occur at the optimal access point within a preset time window; equipment status events refer to events that can reflect changes in the operating status of power electronic equipment, including the time of event occurrence and event type.

[0258] For example, to further confirm the optimal access point To determine whether a device action that could potentially cause secondary disturbances has actually occurred, obtain its set of state events:

[0259] ;

[0260] in, This represents the set of state events for the optimal access point. Indicates the first A state event, Indicates the number of state events.

[0261] Each state event is represented as:

[0262] ;

[0263] in, The moment the state event occurs; This refers to the status event type. Status event types include, but are not limited to: interlocking action, current limiting start, low voltage ride-through control start, control mode switching, PLL abnormality or resynchronization, PWM modulation state change, DC bus overvoltage or undervoltage, AC side current saturation, grid-connected switch action, and filter switching action.

[0264] S702: Based on the type weight of each event in the set of equipment status events and the time matching degree with the excitation time of the best secondary disturbance source, the verifiability of the equipment status is quantified.

[0265] Among them, type weight refers to the degree of support of different types of device state events for secondary disturbances; time matching degree refers to the closeness between the time of occurrence of the device state event and the time of excitation of the optimal secondary disturbance source; device state verifiability refers to the possibility that the device state event can prove that the access point generates a secondary disturbance at that time, with a value range of 0 to 1.

[0266] For example, define a state event type weight function:

[0267] ;

[0268] in, Indicates the type of status event. The degree of support for secondary disturbances.

[0269] The preferred value range is: Locking action: ; Grid connection switch operation: Filter switching action: Rate limiting enabled: Low voltage ride-through control startup: Control mode switching: PWM modulation state change: PLL error or resynchronization: DC bus overvoltage or undervoltage: AC side current saturation: No obvious state events: The weights mentioned above can be adjusted based on the equipment manufacturer's control strategy, field test data, historical fault records, or simulation results. Generally speaking, events that can significantly change the equivalent boundary or output behavior of the access point have higher weights; events that only represent slight operational fluctuations have lower weights.

[0270] Define state event time tolerance parameters Preferably, More preferably, When the device status recording time accuracy is high, A smaller value can be chosen; when the status quantity is uploaded by the communication system or the timestamp has a large error, A larger value can be taken.

[0271] Define the optimal access point at the second perturbation interpretation time. Provability of nearby states:

[0272] ;

[0273] in: This indicates the optimal access point at the time of the second perturbation interpretation. Verifiability of the nearby state; Indicates the weight of the state event type; This represents the time difference between the moment of interpretation of the secondary disturbance and the moment of occurrence of the state event; Indicates the time tolerance of state events.

[0274] The range of values ​​is If in If there are high-weight device status events nearby, then Larger; if there are no relevant device status events nearby, the value is smaller.

[0275] The above method uses equipment status records to verify whether the interpretation of power electronic secondary disturbances has a basis for control or protection actions. If in If there are state events such as current limiting, blocking, low voltage ride-through, or control mode switching in the vicinity, it indicates that the access point may indeed generate a secondary disturbance at that moment; if there are no relevant state events, the source interpretation strength of the power electronic access point should be reduced even if the propagation timing is relatively well matched.

[0276] This embodiment obtains the set of device state events before and after the second disturbance interpretation time of the optimal access point, and combines event type weights and time matching metrics to obtain the device state verifiability, providing a basis for the correction of the access point source interpretability.

[0277] In an exemplary embodiment, by combining the fault point source interpretability, the access point source interpretability, and physical state constraint information, source attribute determination is performed on the transient event to be determined, and the source attribute determination result is obtained, including:

[0278] S801: The access point source interpretability and physical state constraint information are fused to obtain the final interpretability of the access point source.

[0279] Among them, fusion processing refers to combining the basic interpretability of the access point source with the physical state constraint information to correct the interpretability of the access point source by the physical state constraints; the final interpretability of the access point source refers to the interpretability of the access point source after correction by the physical state constraints, and the value range is 0~1.

[0280] For example, the source interpretation strength of power electronic access points is defined as:

[0281] ;

[0282] in: This indicates that the transient event is caused by the optimal power electronics access point. The explanatory strength of the secondary perturbation; This indicates the degree to which the propagation timing conforms to the power electronics access point source model; This represents the confidence factor of the boundary state transition near the secondary source time at the optimal access point; This indicates the verifiability of the optimal access point device state for secondary disturbances.

[0283] The reason for using the product form is that only when all three conditions—propagation timing matching, boundary state change, and evidence of device state—are met simultaneously is the explanation for secondary disturbances at the power electronic access point considered strong. If any one of these conditions is not met, All of these will be significantly weakened.

[0284] Furthermore, the fault source interpretation strength is defined as:

[0285] ;

[0286] in: This indicates the explanatory strength of the transient event being directly triggered by the fault point; This indicates the strength of the basic explanation of the fault source.

[0287] In the basic scheme of this implementation method, Take directly The reason is that the fault source interpretation has been constrained by the search for candidate locations on the line and the propagation residuals of multiple measurement points, and ordinary waveform features are no longer introduced to avoid degenerating this scheme into a multi-feature weighted screening.

[0288] S802: Compare the relative magnitudes of the fault point source explanatory power and the access point source final explanatory power.

[0289] For example, the difference in explanatory power between the two types of sources can be quantified using a ratio. A source attribute discriminant factor is defined to characterize their relative magnitude:

[0290] ;

[0291] in: The source attribute discrimination factor; Explain the intensity of the fault source; Explain the strength of the power electronic access point source; To prevent small positive numbers with a denominator of zero. The preferred range is More preferably .when When the value is large, it indicates that the fault source explanation is stronger than the power electronic secondary source explanation; when When the value is smaller, it indicates that the transient event is more likely to be explained by secondary disturbances at the power electronic access point.

[0292] This step transforms the fault source interpretation capability and the power electronic access point source interpretation capability into two directly comparable strength quantities. This indicates the probability that a transient event is directly triggered by the fault point. This indicates the possibility that a transient event is caused by a secondary disturbance generated by the power electronic access point. Because... Simultaneously constrained by propagation residuals, boundary state transitions, and device state verifiability, this approach avoids misjudging power electronic secondary disturbances based solely on timing matching. This step transforms source attribute discrimination into a competition between the interpretative capabilities of two physical sources, rather than relying on multi-feature weighted filtering based on ordinary waveform features.

[0293] S803: Determine the transient event attribute based on the relative size and the preset source attribute discrimination threshold, and obtain the source attribute discrimination result.

[0294] For example, let the source attribute discrimination threshold be... Preferably, More preferably, .

[0295] when If the transient event is determined to be a direct traveling wave source event of the fault point, it will be output as a reliable fault traveling wave.

[0296] when If the transient event is determined to be a secondary disturbance event at the power electronic access point or a low-confidence transient event, it will not be considered as the preferred traveling wave for subsequent fault location.

[0297] This embodiment obtains the final interpretation degree of the access point source by fusing the access point source interpretation degree with the physical state constraint information, calculates the ratio of the two types of source interpretation strengths to obtain the source attribute discrimination factor, and then compares it with a preset threshold to obtain the source attribute discrimination result, thus realizing accurate discrimination of transient event source attributes based on source interpretation competition.

[0298] In one exemplary embodiment, it further includes:

[0299] Based on the relative size and the preset source attribute discrimination threshold, the source attribute discrimination confidence is calculated; the higher the source attribute discrimination confidence, the higher the stability of the source attribute discrimination result.

[0300] For example, define the source attribute discrimination confidence level:

[0301] ;

[0302] in: Determine the confidence level for the source attribute; The source attribute discrimination factor; The threshold for determining the source attribute; To prevent small positive numbers with a denominator of zero.

[0303] The larger, the more it means The further away from the threshold, the more stable the discrimination result; The smaller, the better. When the threshold is approached, the judgment result has a certain degree of uncertainty.

[0304] This embodiment can quantify the stability of the discrimination result by calculating the discrimination confidence level, which can be used as a basis for the reliability of the discrimination result.

[0305] In one exemplary embodiment, the final output result can be determined as follows:

[0306] ;

[0307] in: The result of the source attribute discrimination; For source attribute labels; when L = direct traveling wave source of the fault point, it indicates that the transient event is a reliable fault traveling wave; when L = secondary disturbance source of the power electronic access point, it indicates that the transient event is not the preferred traveling wave for subsequent fault location. The source attribute discrimination factor; Determine the confidence level for the source attribute; Explain the location of the optimal fault source; The optimal time to explain the source of the fault; Explain the location of the optimal power electronics access point source; This is the optimal time to interpret the secondary disturbance source; Explain the intensity of the fault source; Explain the strength of the power electronic access point source; The minimum overall explained residual for the fault point source; The minimum overall explained residual for power electronic access point sources; This represents the boundary state transition value at the optimal power electronics access point. Verifiability of the optimal power electronics access point state.

[0308] If it is determined to be a reliable fault traveling wave, then it can be... As an initial estimate of the fault location:

[0309] ;

[0310] in, This indicates the initial fault location value used by the subsequent fault location module.

[0311] Alternatively, the set of arrival times of the transient event. Source attribute tag Source attribute discrimination factor Fault source explanation strength Input subsequent single-ended, double-ended, or multi-ended traveling wave ranging modules.

[0312] This embodiment is based on the source attribute discrimination factor. Provide the final source attribute label to clarify whether the transient event can be used as a reliable fault traveling wave for subsequent fault ranging or fault location. This is achieved through the output... , , , , , , , , and After obtaining the results, subsequent modules will not only be able to obtain the judgment conclusion, but also understand the basis and confidence level of the conclusion.

[0313] Please see Figure 2 , Figure 2 This paper presents a preferred implementation scheme for a reliable traveling wave identification method for power electronic access lines based on source interpretation competition. The process includes: first, obtaining the line topology, measurement points, power electronic access point locations, and the arrival times of the transient events to be identified at each measurement point as basic inputs; then, performing parallel interpretation calculations for two types of physical source models: the left branch establishes a direct traveling wave source interpretation model for the fault point, and calculates the single-point time residual and the minimum overall interpretation residual R. F The optimal fault location and time are obtained and then quantified into the fault source fundamental interpretation strength B. F And directly used as the final explanation intensity A for the fault point source. F The right branch simultaneously establishes an interpretation model for the secondary disturbance source at the power electronic access point, and calculates the minimum overall interpretation residual R. E After determining the optimal access point and the secondary source time, physical state constraints are further introduced to calculate the boundary state transition quantity J and the boundary transition reliability factor C at the optimal access point. J Equipment condition verifiability P, and the strength of the interpretation of the access point source fundamentals B. E Multiplying yields the corrected access point source final interpretation strength A. E Then, the ratio of the two types of source interpretation strengths, i.e., the source attribute discriminant factor Θ, is calculated and compared with a preset threshold Θ. th Comparison: If Θ ≥ Θ th If the wave is identified as a reliable fault and input into the subsequent ranging and positioning module, then if Θ < Θ th If the disturbance is identified as a power electronic secondary disturbance or a low-confidence transient, it will not be considered the preferred traveling wave for ranging, and the process will end.

[0314] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0315] Based on the same inventive concept, this application also provides a device for identifying reliable traveling wave faults in power electronic access lines based on source interpretation contention, for implementing the aforementioned method for identifying reliable traveling wave faults in power electronic access lines. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations in the embodiments of the device for identifying reliable traveling wave faults in power electronic access lines based on source interpretation contention provided below can be found in the limitations of the method for identifying reliable traveling wave faults in power electronic access lines based on source interpretation contention described above, and will not be repeated here.

[0316] Please see Figure 3 This invention provides a power electronic access line reliable fault traveling wave identification device based on source interpretation competition, comprising:

[0317] The transient event response module is used to respond to transient events to be identified in power electronic access lines;

[0318] The fault point source interpretation quantification module is used to determine the fault point source explanatory power using the fault point direct traveling wave source interpretation model; the fault point direct traveling wave source interpretation model is used to quantify the fault point source explanatory power based on the first comprehensive deviation; the first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0319] The access point disturbance source interpretation quantification module is used to determine the access point source explanatory power using the power electronic access point secondary disturbance source interpretation model. The power electronic access point secondary disturbance source interpretation model is used to quantify the access point source explanatory power based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming the secondary disturbance of the power electronic access point arrives at each measuring point.

[0320] The physical constraint information acquisition module is used to acquire the physical state constraint information of the power electronic access point;

[0321] The transient source attribute discrimination module is used to combine the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information to perform source attribute discrimination on the transient event to be judged, and obtain the source attribute discrimination result;

[0322] The fault traveling wave result integration module is used to integrate the source attribute discrimination results and the corresponding source interpretation degree to obtain a reliable fault traveling wave identification result indicating the transient event to be discriminated.

[0323] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0324] Reference Figure 4 This invention also provides a computer device, including: a memory and a processor, and a computer program stored in the memory. When the computer program is executed on the processor, it performs the following steps:

[0325] In response to undetermined transient events in power electronic access lines;

[0326] The direct traveling wave source interpretation model of the fault point is used to determine the explanatory power of the fault point source. The direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation. The first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0327] The explanatory power of the access point source is determined by using the secondary disturbance source interpretation model of the power electronic access point. The secondary disturbance source interpretation model of the power electronic access point is used to quantify the explanatory power of the access point source based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that the secondary disturbance of the power electronic access point arrives at each measuring point.

[0328] Obtain physical state constraint information of power electronic access points;

[0329] By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute is determined for the transient event to be judged, and the source attribute determination result is obtained.

[0330] By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

[0331] The computer device may be a desktop computer, laptop, handheld computer, or cloud server, etc. This computer device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that... Figure 4 The examples of computer devices are merely examples and do not constitute a limitation on computer devices. They may include more or fewer components than shown in the illustration, or combinations of certain components, or different components. For example, they may also include input / output devices, network access devices, etc.

[0332] The processor referred to can be a Central Processing Unit (CPU), but it can also be 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. A general-purpose processor can be a microprocessor or any conventional processor.

[0333] In some embodiments, the memory may be an internal storage unit of the computer device, such as a hard drive or RAM. In other embodiments, the memory may be an external storage device of the computer device, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory may include both internal and external storage units of the computer device. The memory is used to store the operating system, applications, boot loader, data, and other programs, such as the program code of the computer program. The memory can also be used to temporarily store data that has been output or will be output.

[0334] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, performs the following steps:

[0335] In response to undetermined transient events in power electronic access lines;

[0336] The direct traveling wave source interpretation model of the fault point is used to determine the explanatory power of the fault point source. The direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation. The first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0337] The explanatory power of the access point source is determined by using the secondary disturbance source interpretation model of the power electronic access point. The secondary disturbance source interpretation model of the power electronic access point is used to quantify the explanatory power of the access point source based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that the secondary disturbance of the power electronic access point arrives at each measuring point.

[0338] Obtain physical state constraint information of power electronic access points;

[0339] By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute is determined for the transient event to be judged, and the source attribute determination result is obtained.

[0340] By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

[0341] In this embodiment, if the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a photographing device / terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0342] This invention provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0343] In response to undetermined transient events in power electronic access lines;

[0344] The direct traveling wave source interpretation model of the fault point is used to determine the explanatory power of the fault point source. The direct traveling wave source interpretation model of the fault point is used to quantify the explanatory power of the fault point source based on the first comprehensive deviation. The first comprehensive deviation is the comprehensive deviation between the actual and theoretical time of arrival at each measuring point of the transient event assuming that is triggered by the line fault point.

[0345] The explanatory power of the access point source is determined by using the secondary disturbance source interpretation model of the power electronic access point. The secondary disturbance source interpretation model of the power electronic access point is used to quantify the explanatory power of the access point source based on the second comprehensive deviation. The second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming that the secondary disturbance of the power electronic access point arrives at each measuring point.

[0346] Obtain physical state constraint information of power electronic access points;

[0347] By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute is determined for the transient event to be judged, and the source attribute determination result is obtained.

[0348] By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

[0349] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0350] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those 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 this application.

[0351] In the embodiments disclosed in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0352] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for identifying reliable fault traveling waves in power electronic access lines based on source interpretation competition, characterized in that, Includes the following steps: In response to undetermined transient events in power electronic access lines; The fault point source explanatory power is determined using a direct traveling wave source interpretation model; the fault point source explanatory power is obtained based on a first comprehensive deviation quantization. The first comprehensive deviation is the combined deviation between the actual and theoretical time of arrival at each measuring point, assuming a transient event triggered by a line fault point. The explanatory power of the access point source is determined using a secondary disturbance source explanation model for power electronic access points; the secondary disturbance source explanation model for power electronic access points is used to obtain the explanatory power of the access point source based on the second comprehensive deviation quantization. The second comprehensive deviation is the combined deviation between the actual and theoretical time of arrival at each measuring point, assuming a transient event caused by a secondary disturbance at the power electronic access point; Obtain the physical state constraint information of the power electronic access point; By combining the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information, the source attribute of the transient event to be identified is determined, and the source attribute determination result is obtained. By integrating the source attribute discrimination results and the corresponding source interpretation degree, a reliable fault traveling wave identification result indicating the transient event to be discriminated is obtained.

2. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation contention as described in claim 1, characterized in that, Using the direct traveling wave source interpretation model at the fault point, the explanatory power of the fault point source is determined, including: Based on the line topology data, a set of candidate fault locations is obtained; For each candidate fault location in the set of candidate fault locations, the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measuring point is calculated using the direct traveling wave source interpretation model of the fault point when the corresponding candidate fault location is used as the fault point source, so as to obtain the first comprehensive deviation of each candidate fault location. The candidate fault location with the smallest first comprehensive deviation is selected as the optimal fault point source interpretation location. The comprehensive deviation value corresponding to the optimal fault source explanation location is quantified as the fault source explanation degree.

3. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation contention as described in claim 1, characterized in that, Using the power electronic access point secondary disturbance source interpretation model, the access point source explanatory power is determined, including: Based on the line topology data and the location data of power electronic access points, a set of power electronic access points is obtained; For each access point in the power electronic access point set, the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measurement point is calculated using the power electronic access point secondary disturbance source interpretation model, when the corresponding access point is used as a secondary disturbance source, to obtain the second comprehensive deviation of each access point; The candidate access point with the smallest second comprehensive deviation is selected as the optimal access point source interpretation location; The comprehensive deviation value corresponding to the optimal access point source interpretation location is quantified as the access point source interpretation degree.

4. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation contention as described in claim 2 or 3, characterized in that, For the fault source and the secondary disturbance source, calculate the comprehensive deviation between the theoretical arrival time and the actual arrival time of the transient event at each measuring point, including: Based on the source location and the traveling wave propagation parameters of the line, calculate the theoretical arrival time of the transient event from the source to each measuring point; obtain the actual arrival time of the transient event from the source to each measuring point. Calculate the single-point time residual between the theoretical arrival time and the actual arrival time for each measuring point; The sum of squares of the single-point time residuals at all measuring points is calculated to obtain the comprehensive deviation value corresponding to the source point.

5. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation competition according to claim 4, characterized in that, The comprehensive deviation value is quantified into the source explanatory power of the corresponding source point, including: Divide the comprehensive deviation value by the number of measuring points to obtain the normalized comprehensive deviation value; The exponential normalization method converts the normalized value of the composite deviation into the source explanatory power of the corresponding source point; the source explanatory power is negatively correlated with the composite deviation value.

6. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation contention as described in claim 1, characterized in that, The physical state constraint information includes boundary state transition amounts; Obtaining the physical state constraint information of the power electronic access point includes: Based on the calculation results of the power electronic access point secondary disturbance source interpretation model, the optimal access point source interpretation location and the corresponding optimal secondary disturbance source interpretation time are determined. Obtain the boundary state data of the optimal access point source interpretation location within a preset time window before and after the optimal secondary disturbance source excitation time; The change in the boundary state data before and after the optimal excitation time of the secondary disturbance source is calculated to obtain the boundary state transition amount.

7. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation contention as described in claim 6, characterized in that, The physical state constraint information also includes the verifiability of the device state; Obtaining the physical state constraint information of the power electronic access point includes: Obtain the set of device status events within a preset time window before and after the optimal secondary disturbance source excitation time for the optimal access point source interpretation location; The verifiability of the device state is quantified based on the type weight of each event in the device state event set and the time matching degree with the excitation time of the optimal secondary disturbance source.

8. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation contention as described in claim 1, characterized in that, Combining the fault point source interpretability, the access point source interpretability, and the physical state constraint information, the source attribute of the transient event to be identified is determined, and the source attribute determination result is obtained, including: The access point source interpretability and the physical state constraint information are fused to obtain the final access point source interpretability; Compare the relative magnitudes of the fault point source explanatory power and the access point source final explanatory power; The transient event attribute is determined based on the relative size and the preset source attribute discrimination threshold, and the source attribute discrimination result is obtained.

9. The method for reliable fault traveling wave identification of power electronic access lines based on source interpretation contention as described in claim 8, characterized in that, Also includes: Based on the relative size and the preset source attribute discrimination threshold, the source attribute discrimination confidence level is calculated; The higher the confidence level of the source attribute discrimination, the higher the stability of the source attribute discrimination result.

10. A power electronic access line reliable fault traveling wave identification device based on source interpretation competition, characterized in that, include: The transient event response module is used to respond to transient events to be identified in power electronic access lines; The fault point source explanation quantification module is used to determine the fault point source explanatory power using the fault point direct traveling wave source explanation model; the fault point direct traveling wave source explanation model is used to obtain the fault point source explanatory power based on the first comprehensive deviation quantization. The first comprehensive deviation is the combined deviation between the actual and theoretical time of arrival at each measuring point, assuming a transient event triggered by a line fault point. The access point disturbance source interpretation quantification module is used to determine the access point source explanatory power using the power electronic access point secondary disturbance source interpretation model; the power electronic access point secondary disturbance source interpretation model is used to quantify the access point source explanatory power based on the second comprehensive deviation; the second comprehensive deviation is the comprehensive deviation between the actual and theoretical time of the transient event assuming the secondary disturbance of the power electronic access point arrives at each measuring point; The physical constraint information acquisition module is used to acquire the physical state constraint information of the power electronic access point; The transient source attribute discrimination module is used to combine the source interpretability of the fault point, the source interpretability of the access point, and the physical state constraint information to perform source attribute discrimination on the transient event to be judged, and obtain the source attribute discrimination result. The fault traveling wave result integration module is used to integrate the source attribute discrimination results and the corresponding source explanatory power to obtain a reliable fault traveling wave identification result indicating the transient event to be discriminated.

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