Automatic test system for distribution terminal full channel comparison and fault backtracking

Abstract

This invention discloses an automated testing system for full-channel comparison and fault backtracking of power distribution terminals. The system includes a longitudinal differential protection module, a channel quality identification module, a harmonic analysis and processing module, a forward-disturbance-reverse linkage detection module, a full-channel comparison module, and a fault backtracking module, all connected or associated sequentially. The system generates protection action criteria signals through the longitudinal differential protection module, evaluates transmission quality through the channel quality identification module, extracts harmonic parameters through the harmonic analysis and processing module, generates linkage detection results through the forward-disturbance-reverse linkage detection module, compares parameters and outputs deviation data through the full-channel comparison module, and locates the fault by combining the relevant results with the system's analysis. This system integrates multiple algorithms and models to achieve multi-dimensional comprehensive evaluation, accurately pinpointing faults and solving problems such as partial detection and delayed backtracking in existing technologies. It improves fault handling efficiency and reliability and is suitable for full-channel testing and fault handling of power distribution terminals.

Description

Technical Field

[0001] This invention relates to the field of automated testing of power distribution terminals, and in particular to an automated testing system for full-channel comparison and fault tracing of power distribution terminals. Background Technology

[0002] With the rapid development of power systems towards intelligence and automation, distribution terminals, as key nodes in the power network, directly impact the safe and reliable operation of the entire power grid through their operational stability and fault handling efficiency. Current distribution network structures are becoming increasingly complex, with a significant increase in the number of terminal devices and a surge in data transmission between channels. Issues such as channel quality fluctuations and harmonic interference are frequent, easily leading to terminal malfunctions or failures. To achieve comprehensive monitoring, accurate comparison, and rapid fault tracing of the operational status of each channel of the distribution terminal, it is urgently necessary to construct an automated testing system integrating multiple professional algorithms and multi-module collaborative operation to meet the high-precision requirements for evaluating the operational status of all channels of the distribution terminal and locating faults in complex power grid environments.

[0003] Existing technologies have significant shortcomings in power distribution terminal channel testing and fault tracing. On the one hand, existing systems mostly use single algorithms or independent modules for local detection, lacking deep integration of multiple technologies such as longitudinal differential protection, channel quality identification, and harmonic analysis. This makes it difficult to comprehensively assess the channel's operating status, resulting in limited ability to identify complex faults. On the other hand, existing fault tracing mechanisms mostly rely on single parameter comparisons or simple logical judgments, failing to establish an integrated linkage detection system of forward simulation-disturbance coupling-reverse fault tolerance. This makes it impossible to accurately trace the specific channel location and time of the fault occurrence, and there is a lag in channel parameter deviation analysis and historical data correlation, affecting the timeliness and accuracy of fault handling. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of existing technologies, this invention provides an automated testing system for full-channel comparison and fault tracing of power distribution terminals.

[0005] The technical solution adopted in this invention is an automated testing system for full-channel comparison and fault tracing of power distribution terminals, including a longitudinal differential protection module, a channel quality identification module, a harmonic analysis and processing module, a forward-disturbance-reverse linkage detection module, a full-channel comparison module, and a fault tracing module; the output terminal of the longitudinal differential protection module is connected to the input terminal of the channel quality identification module, the output terminal of the channel quality identification module is connected to the input terminal of the harmonic analysis and processing module, and the output terminal of the harmonic analysis and processing module is connected to the input terminal of the forward-disturbance-reverse linkage detection module. The output of the disturbance-reverse linkage detection module is connected to the input of the full-channel comparison module and the first input of the fault backtracking module, respectively. The output of the full-channel comparison module is connected to the second input of the fault backtracking module. The longitudinal differential protection module generates a longitudinal differential protection action criterion signal based on the real-time current and voltage signals transmitted by each channel of the distribution terminal by calculating the current difference and voltage difference of each channel. The channel quality identification module receives the longitudinal differential protection action criterion signal and, combined with the signal transmission delay, bit error rate, and signal strength parameters of each channel, performs longitudinal differential protection. The dynamic protection and channel quality identification algorithm quantifies and evaluates the transmission quality of each channel, outputting channel quality evaluation results. The harmonic analysis processing module receives the channel quality evaluation results, extracts harmonic components from the transmitted signals of each channel, calculates the harmonic amplitude, phase, and harmonic order using a harmonic analysis model, and outputs harmonic analysis data. The forward-disturbance-reverse linkage detection module receives the harmonic analysis data and employs a forward simulation-disturbance coupling-reverse fault tolerance integrated linkage detection algorithm. First, it performs forward simulation on the normal operating state of each channel to generate a reference signal. Then, it applies a preset disturbance to the reference signal to generate a disturbance signal. Finally, it performs reverse fault tolerance verification on the disturbance signal to generate linkage detection results. The full-channel comparison module receives the linkage detection results, compares the real-time transmission parameters of each channel with the reference parameters in the linkage detection results one by one, calculates the parameter deviation value, and outputs channel comparison data. The fault backtracking module receives the linkage detection results and channel comparison data. Based on the deviation value exceeding a preset threshold in the channel comparison data, combined with the disturbance response characteristics in the linkage detection results, it locates the channel location and time node where the fault occurred and outputs fault backtracking information.

[0006] Furthermore, when the longitudinal differential protection module and the channel quality identification module work together, the comprehensive channel quality assessment value is calculated using the following model formula: in, This is a comprehensive evaluation value for channel quality. The weighting coefficients and , This is the measured value of the longitudinal differential current. The threshold value for setting the longitudinal differential current is... This is the measured value of signal transmission delay. This is the allowable threshold for signal transmission delay. This is the measured bit error rate. This represents the maximum permissible bit error rate.

[0007] Furthermore, when the harmonic analysis and processing module processes harmonic components using a harmonic analysis model, it calculates the harmonic distortion rate using the following model formula: in, Total harmonic distortion (THD) For harmonic order, The highest harmonic order, For the first The amplitude of the second harmonic. This represents the amplitude of the fundamental frequency.

[0008] Furthermore, during the forward simulation process, the forward-disturbance-reverse linkage detection module generates a reference signal using the following model formula: in, for The reference signal at time, for The original input signal at time 10:00. Number the influencing factors. The total number of influencing factors. for Time of the first Signal bias caused by various influencing factors For the first Correction coefficients for each influencing factor.

[0009] Furthermore, the forward-disturbance-reverse linkage detection module generates a disturbance signal during the disturbance coupling process using the following model formula: in, for The disturbance signal at any given moment. for The reference signal at time, For the disturbance amplitude coefficient, The perturbation angular frequency, This represents the initial phase of the disturbance.

[0010] Furthermore, when performing parameter comparison, the full-channel comparison module calculates the channel parameter deviation using the following model formula: in, For the first The parameter deviation of each channel As parameter number, For the total number of parameters, For the first The first channel Measured values ​​of each parameter For the first The baseline values ​​for each parameter, This is the average of the baseline values ​​for all parameters.

[0011] Furthermore, the harmonic analysis and processing module includes a harmonic component extraction unit, a harmonic parameter calculation unit, a harmonic data integration unit, and a harmonic feature output unit. The harmonic component extraction unit receives the channel quality assessment results, performs Fourier transform on the transmitted signals of each channel, decomposes the signals into components of different frequencies, and separates the fundamental component and each harmonic component. The harmonic parameter calculation unit analyzes each separated harmonic component, calculates the amplitude, phase, and frequency parameters of each harmonic, wherein the amplitude is determined by calculating the ratio of the peak value to the effective value of the harmonic component, and the phase is determined by calculating the phase difference by comparing it with the fundamental phase. The harmonic data integration unit sorts the parameters of each harmonic according to the harmonic order to form a structured harmonic data set, and associates it with the corresponding channel identification information. The harmonic feature output unit performs format conversion on the integrated harmonic data set, generates harmonic analysis data that meets the input requirements of the forward-disturbance-reverse linkage detection module, and transmits it.

[0012] Furthermore, the forward-disturbance-reverse linkage detection module includes a forward simulation unit, a disturbance coupling unit, a reverse fault-tolerant verification unit, and a linkage result generation unit. The forward simulation unit receives harmonic analysis data, establishes a normal operating state model based on the historical operating parameters of each channel of the power distribution terminal, inputs the harmonic analysis data into the model for simulation calculation, and generates a reference signal for each channel under normal conditions. The disturbance coupling unit calls the disturbance type and parameters from a preset disturbance parameter library, superimposes the disturbance parameters and the reference signal according to preset coupling rules, and generates a disturbance signal containing disturbance characteristics. The reverse fault-tolerant verification unit performs reverse deduction on the disturbance signal, and determines whether the disturbance signal can be corrected by the fault-tolerant mechanism during transmission by comparing the deviation between the deduction result and the reference signal, and records the signal change data during the fault-tolerant verification process. The linkage result generation unit integrates the reference signal from forward simulation, the disturbance signal from disturbance coupling, and the signal change data from reverse fault-tolerant verification to form a linkage detection result, which is then transmitted to the full-channel comparison module and the fault backtracking module, respectively.

[0013] Furthermore, the full-channel comparison module includes a parameter acquisition unit, a reference parameter retrieval unit, a parameter comparison unit, and a comparison data output unit. The parameter acquisition unit collects the transmission parameters of each power distribution terminal channel in real time, including signal transmission rate, signal attenuation, and data integrity indicators, and marks the collected parameters according to timestamps. The reference parameter retrieval unit receives the linkage detection results from the forward-disturbance-reverse linkage detection module, extracts the reference parameters corresponding to each channel, establishes a reference parameter database, and associates it with the channel number. The parameter comparison unit compares the real-time parameters collected by the parameter acquisition unit with the reference parameters of the corresponding channels in the reference parameter database point by point, calculates the absolute deviation value and relative deviation value of each parameter, and marks the parameters that exceed the allowable deviation range. The comparison data output unit summarizes the deviation values, out-of-tolerance parameter identifiers, and corresponding channel information after comparison, generates channel comparison data, and transmits it to the fault backtracking module.

[0014] An automated testing system for full-channel comparison and fault tracing of power distribution terminals. The system operation includes the following steps: Step S1: Continuously monitor the current and voltage signals of each channel of the power distribution terminal through the longitudinal differential protection module, calculate the current difference and voltage difference and generate the corresponding protection action criterion signal; Step S2: Transmit the protection action criterion signal to the channel quality identification module. Combine the signal transmission delay, bit error rate, and signal strength parameters of each channel, use the longitudinal differential protection and channel quality identification algorithm to quantitatively evaluate the transmission quality of each channel and output the evaluation results. Step S3: Transmit the evaluation results to the harmonic analysis and processing module, extract the harmonic components in each channel signal, calculate the harmonic amplitude, phase and order through the harmonic analysis model, and output the harmonic analysis data; Step S4: Transmit the harmonic analysis data to the forward-disturbance-reverse linkage detection module. First, generate a reference signal through forward simulation, then apply a preset disturbance to generate a disturbance signal, and finally perform reverse fault tolerance verification to generate the linkage detection result. Step S5: Transmit the linkage detection results to the full-channel comparison module, compare them one by one with the real-time transmission parameters of each channel, calculate the parameter deviation value and output the channel comparison data. Step S6: Transmit the linkage detection results and channel comparison data to the fault backtracking module. Based on the over-threshold deviation value and disturbance response characteristics, locate the fault channel location and time node and output fault backtracking information.

[0015] Beneficial Effects: This invention proposes an automated testing system for full-channel comparison and fault backtracking of power distribution terminals. Through multi-module collaboration and multi-algorithm integration, it comprehensively improves the efficiency of power distribution terminal channel testing and fault handling. It integrates technologies such as longitudinal differential protection, channel quality identification, and harmonic analysis. By leveraging the linkage between the longitudinal differential protection module and the channel quality identification module, combined with the accurate analysis of harmonic components by the harmonic analysis module, it achieves a comprehensive evaluation of the channel's operating status. This overcomes the limitations of existing technologies that rely on single algorithms or independent modules for local detection, significantly improving the ability to identify complex faults. Simultaneously, by constructing an integrated detection system through a forward-disturbance-reverse linkage detection module, and combining parameter comparison by the full-channel comparison module with feature analysis by the fault backtracking module, it can accurately locate the fault channel position and time point. This solves the problem of existing technologies relying on single parameters or simple logic for fault backtracking, and the lag in correlation analysis, effectively improving the timeliness and accuracy of fault handling, and providing a reliable guarantee for the stable operation of the power system. Attached Figure Description

[0016] Figure 1 This is a diagram showing the system module composition of the present invention; Figure 2 This is a flowchart of the system operation of the present invention. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, the automated testing system for full-channel comparison and fault tracing of power distribution terminals includes a longitudinal differential protection module, a channel quality identification module, a harmonic analysis and processing module, a forward-disturbance-reverse linkage detection module, a full-channel comparison module, and a fault tracing module. The output of the longitudinal differential protection module is connected to the input of the channel quality identification module. The output of the channel quality identification module is connected to the input of the harmonic analysis and processing module. The output of the harmonic analysis and processing module is connected to the input of the forward-disturbance-reverse linkage detection module. The output of the forward-disturbance-reverse linkage detection module is connected to the input of the full-channel comparison module and the first input of the fault backtracking module, respectively. The output of the full-channel comparison module is connected to the second input of the fault backtracking module. The longitudinal differential protection module generates a longitudinal differential protection action criterion signal by calculating the current difference and voltage difference of each channel based on the real-time current and voltage signals transmitted by each channel of the power distribution terminal. Specifically, the longitudinal differential protection module is a fundamental component of the automated testing system for full-channel comparison and fault backtracking of power distribution terminals. Its core function is to monitor and analyze the real-time current and voltage signals transmitted through each channel of the power distribution terminal, providing initial protection action basis for subsequent channel quality assessment and harmonic analysis. The technical parameters relied upon by this module mainly include current difference threshold, voltage difference threshold, and signal sampling frequency. The current difference threshold is typically set between 5% and 15% of the rated current, and the voltage difference threshold is set between 2% and 8% of the rated voltage. The signal sampling frequency is determined based on the communication rate of the power distribution terminal, generally between 50Hz and 2000Hz, to ensure timely detection of subtle changes in current and voltage. These parameter settings directly affect the accuracy of the longitudinal differential protection action criteria signal, and their significance lies in quickly identifying potential faults such as short circuits and overloads in each channel of the power distribution terminal, providing the first line of defense for the stable operation of the entire system.

[0019] In practical implementation, the longitudinal differential protection module first continuously collects current and voltage signals from each channel of the distribution terminal according to the set signal sampling frequency. The collected signals are temporarily stored digitally in the module's buffer unit. Then, the module calculates the difference between the current signals of different channels at the same time, i.e., it calculates the current difference between any two channels and compares this difference with a preset current difference threshold. Simultaneously, the same process is performed on the voltage signals, calculating the voltage difference and comparing it with a voltage difference threshold. When the current difference or voltage difference of a certain channel exceeds the corresponding threshold, the module immediately activates the protection action logic, generating a longitudinal differential protection action criterion signal. This signal contains the identification information of the faulty channel, the timestamp of the fault occurrence, and the specific value of the current or voltage difference. The generated criterion signal is transmitted to the channel quality identification module through the module's output interface, providing a clear direction of suspected fault for subsequent channel quality assessment. Throughout the process, the module stores the collected raw signals and calculated difference data in real time for 24 hours, so that the original data can be retrieved for verification during subsequent fault backtracking.

[0020] The channel quality identification module receives the longitudinal differential protection action criterion signal, combines the signal transmission delay, bit error rate, and signal strength parameters of each channel, and uses the longitudinal differential protection and channel quality identification algorithm to quantitatively evaluate the transmission quality of each channel and output the channel quality evaluation result. Specifically, the channel quality identification module receives the protection action criterion signal from the longitudinal differential protection module. Its main function is to quantitatively evaluate the transmission quality of each channel by combining the relevant parameters of signal transmission in each channel of the distribution terminal, providing a channel-level quality basis for subsequent harmonic analysis and processing. Key technical parameters involved in this module include signal transmission delay, bit error rate, and signal strength. Signal transmission delay is typically required to be controlled within 10ms, the bit error rate must be below 10^-6, and signal strength is measured by the power of the received signal, generally not lower than -85dBm. These parameters reflect the channel transmission performance from different dimensions. Their significance lies in the fact that by analyzing these parameters, it is possible to accurately determine whether the channel is in a stable transmission state and whether channel problems have caused distortion or delay in the protection action criterion signal, thus providing a reliable channel quality reference for subsequent module processing.

[0021] In practical implementation, after receiving the longitudinal differential protection action criterion signal, the channel quality identification module first extracts the identification information of the faulty channel from the signal. Then, for the channel corresponding to the identification and other related channels, it initiates a parameter acquisition process. The module collects the signal transmission delay of each channel in real time through the communication interface with the power distribution terminal. The acquisition method involves sending 10 test data packets every 100ms, calculating the time difference between the transmission and reception of the data packets, and taking the average value as the transmission delay for that period. For bit error rate (BER) acquisition, the module calculates the ratio of the number of erroneous bits in the received data packets to the total number of bits within one minute. Signal strength is monitored in real time through the module's built-in signal detection circuit, recording the power value of the received signal every 50ms. After acquisition, the module calls the longitudinal differential protection and channel quality identification algorithm to compare the acquired transmission delay, BER, and signal strength with their respective preset thresholds, calculates the deviation of each parameter, and then calculates the comprehensive channel quality evaluation value for each channel based on the weights of each parameter (transmission delay weight 0.4, BER weight 0.3, signal strength weight 0.3). Channels with an evaluation score higher than 80 (out of 100) are considered to have good transmission quality, those between 60 and 80 are considered basically qualified, and those below 60 are considered unqualified. Finally, the module compiles the evaluation results of each channel, the specific values ​​of each parameter, and the channel identification information into a channel quality evaluation result, which is then transmitted to the harmonic analysis and processing module through the output terminal.

[0022] The harmonic analysis and processing module receives the channel quality assessment results, extracts the harmonic components in the transmitted signals of each channel, calculates the harmonic amplitude, phase and harmonic order through the harmonic analysis model, and outputs harmonic analysis data. Specifically, the harmonic analysis and processing module receives the channel quality assessment results output by the channel quality identification module. Its core task is to conduct in-depth analysis of the harmonic components in the transmitted signals of each channel, extract relevant parameters, and provide harmonic-level characteristic data for the forward-disturbance-reverse linkage detection module. The technical parameters this module focuses on mainly include harmonic order, harmonic amplitude, and harmonic phase. Harmonic order analysis typically extends to the 50th order. Harmonic amplitude is expressed as a percentage of the fundamental frequency amplitude, generally requiring the sum of all harmonic amplitudes to not exceed 20% of the fundamental frequency amplitude. Harmonic phase is measured by the difference between the harmonic phase and the fundamental frequency phase, ranging from 0° to 360°. The significance of these parameters lies in the fact that the presence of harmonics affects the accuracy and stability of signal transmission in the power distribution terminal. By extracting and analyzing harmonic parameters, the degree of harmonic interference to each channel signal can be determined, providing a targeted processing basis for subsequent linkage detection.

[0023] In the specific implementation process, the harmonic analysis and processing module first analyzes the received channel quality assessment results, selecting channels that meet or exceed the assessment results as key analysis targets. Channels that fail the assessment are also recorded for subsequent investigation. Subsequently, the module intercepts the signals transmitted through these channels for 10 seconds, maintaining the sampling frequency consistent with the longitudinal differential protection module to ensure signal continuity. After interception, the module performs a Fourier transform on the signal, converting the time-domain signal to a frequency-domain signal, thereby separating the fundamental component and each harmonic component. For each separated harmonic, the module calculates its amplitude by measuring the peak value of the harmonic signal and comparing it with the peak value of the fundamental signal, obtaining the harmonic amplitude as a percentage of the fundamental amplitude. When calculating the harmonic phase, the fundamental phase is used as a reference, and the phase difference measurement circuit obtains the phase difference between each harmonic and the fundamental. Simultaneously, the module records the frequency corresponding to each harmonic, i.e., integer multiples of the fundamental frequency, to determine the harmonic order. After completing all parameter calculations, the module categorizes and organizes the harmonic order, harmonic amplitude, harmonic phase, and other parameters of each channel according to the channel identifier, forming structured harmonic analysis data. The data format adopts the standard power system data exchange format so that the forward-disturbance-reverse linkage detection module can directly read and process it. Finally, the organized harmonic analysis data is transmitted out through the output terminal.

[0024] The forward-disturbance-reverse linkage detection module receives harmonic analysis data and adopts a forward simulation-disturbance coupling-reverse fault tolerance integrated linkage detection algorithm. First, it performs forward simulation on the normal operation state of each channel to generate a reference signal. Then, it applies a preset disturbance to the reference signal to generate a disturbance signal. Finally, it performs reverse fault tolerance verification on the disturbance signal to generate linkage detection results. Specifically, the forward-disturbance-reverse linkage detection module receives harmonic analysis data from the harmonic analysis and processing module. Its main function is to use a forward simulation-disturbance coupling-reverse fault-tolerance integrated linkage detection algorithm to comprehensively detect the operating status of each channel in the power distribution terminal, generate linkage detection results, and provide key detection data for full-channel comparison and fault backtracking. The technical parameters involved in this module include the reference signal deviation range, disturbance type and intensity, and fault tolerance verification threshold. The reference signal deviation range is typically controlled within ±2%, and disturbance types include voltage fluctuations and frequency offsets. The voltage fluctuation amplitude is set to ±5% of the rated voltage, the frequency offset range is ±0.5Hz, and the fault tolerance verification threshold is set according to the importance of the signal: ±1% for critical signals and ±3% for general signals. The significance of these parameter settings is that by simulating normal conditions, applying disturbances, and performing fault tolerance verification, the performance of the channel under different operating conditions can be comprehensively tested, determining whether the channel has the ability to resist disturbances and self-repair, providing a comprehensive detection basis for accurately assessing channel quality.

[0025] In practical implementation, the forward-disturbance-reverse linkage detection module first performs a forward simulation process. Based on the fundamental and harmonic parameters of each channel in the harmonic analysis data, and combined with the rated operating parameters of the power distribution terminal, the module constructs a normal operating state model for each channel. The model input consists of parameters such as the fundamental amplitude and frequency from the harmonic analysis data. The model generates a reference signal for each channel under normal operating conditions through calculation. The duration of this reference signal is 5 minutes, and all parameters must be controlled within a preset deviation range. If the deviation exceeds the range, the model parameters are readjusted and recalculated. Next, a disturbance coupling process is performed. The module selects a suitable disturbance type from a preset disturbance parameter library. For voltage fluctuation disturbances, the voltage parameters of the reference signal are adjusted according to the set amplitude, such as adjusting a signal with a rated voltage of 220V to 209V and 231V respectively; for frequency offset disturbances, the frequency of the reference signal is adjusted from 50Hz to 49.5Hz and 50.5Hz respectively. These disturbance parameters are superimposed on the reference signal according to a time series to generate a disturbance signal containing disturbance characteristics. The duration of the disturbance signal is the same as that of the reference signal. Finally, a reverse fault-tolerant verification process is performed. The module inputs the disturbance signal into the simulated channel transmission system, receives the transmitted signal, compares it with the reference signal, and calculates the signal deviation. For critical signals, if the deviation is within ±1%, the fault-tolerant verification is considered passed; for general signals, a deviation within ±3% is considered passed. The module records the changes in signal deviation during the verification process, integrates the reference signal, disturbance signal, and fault-tolerant verification results to form a linked detection result, which is then transmitted to the full-channel comparison module and the fault backtracking module, respectively.

[0026] The full-channel comparison module receives the linkage detection results, compares the real-time transmission parameters of each channel with the benchmark parameters in the linkage detection results one by one, calculates the parameter deviation value, and outputs the channel comparison data. Specifically, the full-channel comparison module receives the linkage detection results output by the forward-disturbance-reverse linkage detection module. Its main function is to compare the real-time transmission parameters of each channel with the benchmark parameters in the linkage detection results, calculate the parameter deviation value, and provide comparative data support for fault backtracking. The technical parameters involved in this module include parameter comparison accuracy, deviation threshold, and comparison cycle. The parameter comparison accuracy requirement is 0.1%, and the deviation threshold is set according to the parameter type, such as ±3% of rated current for current parameters and ±2% of rated voltage for voltage parameters. The comparison cycle is set to once per minute. The significance of these parameters is that through high-precision, periodic comparisons, deviations between the parameters of each channel and the benchmark parameters can be detected in a timely manner, accurately determining whether there are abnormalities in the channels, and providing precise comparative basis for fault location.

[0027] In the specific implementation process, the full-channel comparison module first extracts the reference parameters of each channel from the linkage detection results, including reference current, reference voltage, reference frequency, etc., and stores these parameters in the reference parameter database according to the channel number. Subsequently, the module starts a real-time parameter acquisition program, connecting to the sensor interface of the power distribution terminal, and acquires the real-time transmission parameters of each channel every minute. The acquired parameter types are consistent with the reference parameters, such as real-time current, real-time voltage, and real-time frequency. The accuracy of the acquired data is controlled within 0.1% to ensure the accuracy of the comparison. After acquisition, the module compares the real-time parameters of each channel with the corresponding reference parameters in the reference parameter database one by one. The comparison method is to calculate the absolute difference and relative difference between the real-time parameters and the reference parameters. For example, for a channel with a rated current of 100A and a reference current of 100A, if the real-time current is 102A, the absolute difference is 2A, and the relative difference is 2%. The calculated relative difference is compared with a preset deviation threshold. For example, if the relative difference of the current parameter is less than ±3% of the threshold (2%), it is considered normal. If the real-time voltage of a channel is 225V and the reference voltage is 220V, and the relative difference is 2.27%, exceeding the ±2% threshold, it is marked as an out-of-tolerance parameter. The module summarizes the parameter deviation values, out-of-tolerance parameter identifiers, and corresponding channel information for all channels to form channel comparison data, which is transmitted to the fault backtracking module through the output terminal. Simultaneously, the module stores each comparison result in a local database for 30 days for subsequent querying and analysis.

[0028] The fault backtracking module receives the linkage detection results and channel comparison data. Based on the deviation value exceeding the preset threshold in the channel comparison data, combined with the disturbance response characteristics in the linkage detection results, it locates the channel location and time node where the fault occurred and outputs fault backtracking information.

[0029] Specifically, the fault tracing module receives the linkage detection results from the forward-disturbance-reverse linkage detection module and the channel comparison data from the full-channel comparison module. Its core function is to locate the channel location and time node where the fault occurred based on this data, and output fault tracing information to provide accurate basis for fault handling in the power distribution terminal. The technical parameters involved in this module include fault judgment threshold, timestamp accuracy, and tracing depth. The fault judgment threshold is consistent with the deviation threshold of the full-channel comparison module, the timestamp accuracy is required to be at the millisecond level, and the tracing depth is set to the operating data within the most recent 24 hours. The significance of these parameters is that, through clear fault judgment standards, accurate time recording, and sufficient tracing depth, the source and development process of the fault can be accurately traced, providing detailed information support for rapid fault elimination.

[0030] In practice, the fault backtracking module first analyzes the received channel comparison data, filtering out channel information corresponding to deviation values ​​exceeding a preset threshold; these channels are identified as suspected fault channels. Simultaneously, the module extracts signal characteristic data from the linkage detection results for these suspected channels during forward simulation, disturbance coupling, and reverse fault tolerance verification processes, including the parameters of the reference signal, the response of the disturbance signal, and the deviation records of the fault tolerance verification. Next, the module performs correlation analysis between the real-time parameter deviation data of the suspected channels and the signal characteristic data in the linkage detection results. By comparing the similarity between the real-time deviation value and the disturbance response characteristics, it determines whether the fault is caused by a disturbance. For example, if the real-time voltage deviation of a channel is consistent with the response characteristics of the voltage fluctuation disturbance applied during disturbance coupling, it is preliminarily determined that the fault is related to voltage fluctuations. After determining the suspected cause of the fault, the module retrieves the timestamp data of these channels before and after the fault occurrence period, with timestamp accuracy down to milliseconds. By analyzing the parameter change trends on the time series, it determines the specific time node where the fault occurred, i.e., the moment when the parameter first exceeded the threshold. Subsequently, based on the required backtracking depth, the module retrieves operational data for the channel within the 24 hours prior to the fault, including longitudinal differential protection signals, channel quality assessment results, and harmonic analysis data, constructing a timeline of fault development and recording detailed parameter changes at each stage. Finally, the module compiles the fault channel identifier, the time of fault occurrence, fault characteristic parameters, and associated historical data into fault backtracking information, outputting it to the power distribution terminal's monitoring system to provide maintenance personnel with a clear and detailed fault tracing report.

[0031] Preferably, when the longitudinal differential protection module and the channel quality identification module work together, the comprehensive channel quality assessment value is calculated using the following model formula: in, This is a comprehensive evaluation value for channel quality. The weighting coefficients and , This is the measured value of the longitudinal differential current. The threshold value for setting the longitudinal differential current is... This is the measured value of signal transmission delay. This is the allowable threshold for signal transmission delay. This is the measured bit error rate. This represents the maximum permissible bit error rate.

[0032] Specifically, the collaborative operation of the longitudinal differential protection module and the channel quality identification module hinges on deriving a comprehensive channel quality assessment value through a specific calculation method, thus fully reflecting the transmission performance of the distribution terminal channel. This assessment value comprehensively considers key parameters such as longitudinal differential current, signal transmission delay, and bit error rate. The weighting of each parameter has been verified through extensive experiments, accurately reflecting the degree of influence of different parameters on channel quality. Specifically, the ratio of the measured longitudinal differential current to the setting threshold reflects the deviation of the current signal; a smaller ratio indicates a more stable current. The ratio of the measured signal transmission delay to the allowable threshold reflects the timeliness of signal transmission; a smaller ratio indicates that the delay meets requirements. The ratio of the measured bit error rate to the maximum allowable bit error rate considers the accuracy of data transmission; a larger value indicates a less severe bit error situation. During implementation, the longitudinal differential protection module continuously collects current signals from each channel, calculates the measured value of the longitudinal differential current, and compares it with a preset setting threshold to obtain the corresponding ratio. The channel quality identification module monitors signal transmission delay and bit error rate in real time, calculating the ratio of these two parameters to their respective thresholds. Subsequently, these three ratios are weighted and summed according to set weighting coefficients to obtain a comprehensive channel quality evaluation value. A high evaluation value indicates good channel quality, ensuring stable signal transmission; a low evaluation value indicates a transmission problem in the channel, requiring further investigation. This collaborative calculation method organically combines the current signal characteristics of the longitudinal differential protection with the channel transmission quality parameters, achieving a more comprehensive and accurate evaluation of channel quality. This provides a reliable channel quality basis for subsequent harmonic analysis and processing, ensuring that the entire automated testing system can accurately identify channel anomalies and improve the system's ability to predict faults.

[0033] Preferably, when the harmonic analysis processing module processes harmonic components using a harmonic analysis model, it calculates the harmonic distortion rate using the following model formula: in, Total harmonic distortion (THD) For harmonic order, The highest harmonic order, For the first The amplitude of the second harmonic. This represents the amplitude of the fundamental frequency.

[0034] Specifically, the harmonic analysis processing module calculates the total harmonic distortion (THD) using a harmonic analysis model. This parameter is a crucial indicator for measuring the degree of harmonic interference in the transmitted signal of a power distribution terminal channel, and it is of key significance for evaluating signal quality. The THD calculation is based on the relationship between the amplitude of each harmonic and the fundamental frequency amplitude. By converting the ratio of the square root of the sum of the squares of each harmonic amplitude to the fundamental frequency amplitude as a percentage, the influence of harmonic components on the fundamental signal can be intuitively reflected. Regarding technical parameters, the harmonic order is typically analyzed up to the 50th order. This is because higher-order harmonics have smaller amplitudes and relatively limited impact on signal quality, while the first 50 harmonics cover the vast majority of harmonic components that may significantly interfere with signal transmission. The fundamental frequency amplitude serves as a reference, and its accuracy directly affects the calculation accuracy of the THD. Therefore, high-precision detection equipment must be used during the measurement process to ensure that the measurement error of the fundamental frequency amplitude is controlled within a small range. In terms of implementation, the harmonic analysis and processing module first performs a Fourier transform on the received signal, converting the time-domain signal into a frequency-domain signal, thereby separating the fundamental component and each harmonic component. Then, the amplitude of each harmonic is measured one by one, and its square value is calculated. These squared values ​​are then summed and the square root is taken to obtain the comprehensive harmonic amplitude value. This comprehensive value is then compared with the fundamental amplitude and converted to a percentage to obtain the total harmonic distortion rate (THD). Generally, the THD needs to be controlled within a certain range. If it exceeds the preset standard, it indicates that the signal is severely affected by harmonic interference, which may affect the normal operation of the power distribution terminal. Through this calculation process, the degree of harmonic interference can be accurately quantified, providing detailed harmonic characteristic data for subsequent forward-disturbance-reverse linkage detection. This allows the linkage detection module to specifically simulate the channel operating state under different harmonic interference conditions, improving the system's ability to detect harmonic-related faults.

[0035] Preferably, the forward-disturbance-reverse linkage detection module generates a reference signal during the forward simulation process using the following model formula: in, for The reference signal at time, for The original input signal at time 10:00. Number the influencing factors. The total number of influencing factors. for Time of the first Signal bias caused by various influencing factors For the first Correction coefficients for each influencing factor.

[0036] Specifically, the process of generating a reference signal during the forward simulation of the forward-disturbance-reverse linkage detection module is crucial. This reference signal serves as the standard for subsequent disturbance coupling and reverse fault tolerance verification, and its accuracy and reliability directly impact the overall linkage detection effect. The core of this process lies in comprehensively considering the original input signal and signal deviations caused by various influencing factors, and adjusting these deviations using correction coefficients to generate a reference signal that accurately reflects the normal operating state of the channel. Regarding technical parameters, the number of influencing factors is determined based on the actual operating environment of the power distribution terminal, typically including common factors such as temperature, humidity, and power fluctuations. Each influencing factor corresponds to a specific correction coefficient, derived through long-term monitoring and data analysis, accurately reflecting the degree of influence of that factor on the signal. The acquisition frequency of the original input signal is consistent with that of the longitudinal differential protection module to ensure signal continuity and consistency. During implementation, the forward simulation unit first receives harmonic analysis data from the harmonic analysis processing module, extracting the original input signal, which contains the characteristic information of the fundamental frequency and each harmonic. Subsequently, various factors affecting channel signal transmission are identified, and for each influencing factor, the resulting signal deviation is calculated based on its specific value under the current operating environment. Next, the signal deviation of each influencing factor is multiplied by its corresponding correction coefficient to obtain the corrected deviation value. Then, all corrected deviation values ​​are summed and added to the original input signal to generate the reference signal. During the generation process, various parameters of the reference signal need to be monitored in real time to ensure they are within the preset deviation range. If they exceed the range, the correction coefficients of the influencing factors are readjusted until the reference signal meets the requirements. The duration of the generated reference signal is typically set to 5 minutes to cover a sufficient number of signal cycles and comprehensively reflect the normal operating characteristics of the channel. The reference signal generated in this way can comprehensively consider the influence of various environmental factors and the signal's own characteristics, providing a reliable reference for subsequent disturbance coupling. This makes the generation of disturbance signals more targeted, thereby improving the accuracy of reverse fault tolerance verification and ensuring that the linkage detection results can truly reflect the channel's operating performance under normal and disturbance conditions.

[0037] Preferably, the forward-disturbance-reverse linkage detection module generates a disturbance signal during the disturbance coupling process using the following model formula: in, for The disturbance signal at any given moment. for The reference signal at time, For the disturbance amplitude coefficient, The perturbation angular frequency, This represents the initial phase of the disturbance.

[0038] Specifically, the forward-disturbance-reverse linkage detection module generates a disturbance signal during disturbance coupling. This signal generation aims to simulate various interference scenarios that may occur in actual operation, verifying the channel's resistance and fault tolerance. This process is achieved by superimposing a specific disturbance function onto a reference signal. The parameter settings of the disturbance function directly determine the type, intensity, and variation pattern of the disturbance. Regarding technical parameters, the disturbance amplitude coefficient determines the magnitude of the disturbance, typically set based on the anti-interference capability of the distribution terminal and the actual range of possible interference intensity, generally between 0.01 and 0.1, to ensure that the disturbance simulates actual interference without causing excessive damage to the channel. The disturbance angular frequency reflects the rate of change of the disturbance, and its value is related to the power system's power frequency and the frequencies of common interference sources, usually selected within the range of 5-50Hz to cover most possible disturbance frequencies. The initial disturbance phase is used to adjust the initial state of the disturbance signal, ensuring the consistency and repeatability of the disturbance applied at different time points. During implementation, the perturbation coupling unit first obtains a reference signal generated by the forward simulation unit. This signal has undergone rigorous verification and can represent the normal operating state of the channel. Then, based on preset perturbation parameters, the specific values ​​of the perturbation amplitude coefficient, angular frequency, and initial phase are determined. A perturbation function is constructed in the form of a sine function. Multiplying the reference signal by the perturbation function yields the perturbation signal. During generation, it is necessary to ensure that the perturbation signal and the reference signal are synchronized in time; that is, the reference signal at the same moment corresponds to the perturbation signal at the same moment. The duration of the perturbation signal is the same as that of the reference signal to ensure that the channel is perturbed within the same time range. The generated perturbation signal needs to undergo preliminary verification to check whether its amplitude variation conforms to the preset perturbation intensity and whether the frequency variation is within the set angular frequency range. If deviations are found, the corresponding parameters are adjusted and the signal is regenerated. The disturbance signal generated in this way can realistically simulate common disturbances such as voltage fluctuations and frequency shifts, providing a suitable test signal for subsequent reverse fault tolerance verification. This enables the verification process to accurately evaluate the transmission performance and fault tolerance capability of the channel when subjected to disturbances, thereby improving the detection and location accuracy of disturbance-related faults in the entire system.

[0039] Preferably, when the full-channel comparison module performs parameter comparison, it calculates the channel parameter deviation using the following model formula: in, For the first The parameter deviation of each channel As parameter number, For the total number of parameters, For the first The first channel Measured values ​​of each parameter For the first The baseline values ​​for each parameter, This is the average of the baseline values ​​for all parameters.

[0040] Specifically, the process of calculating the channel parameter deviation for the full-channel comparison module is crucial. Parameter deviation is an important indicator that measures the degree of deviation between the real-time transmission parameters of each channel and the reference parameters. This indicator enables rapid identification of abnormal channels and provides key comparative data for fault tracing. The calculation process comprehensively considers the absolute deviation between the measured values ​​of each parameter and the reference values, and normalizes them using average values ​​to eliminate the influence of differences in the magnitude of different parameters, ensuring comparability of the deviations. Regarding technical parameters, the total number of parameters is determined based on the specific functions of the distribution terminal, typically including key parameters such as current, voltage, frequency, and signal strength. Each parameter has a corresponding reference value, which comes from the linkage detection results generated by the forward-disturbance-reverse linkage detection module. These reference values ​​undergo rigorous verification and correction to ensure their accuracy. The calculation accuracy of the parameter deviation is required to reach 0.1% to ensure that subtle parameter changes can be captured. During implementation, the full-channel comparison module first retrieves the corresponding reference parameters for each channel from the reference parameter database, and simultaneously starts the real-time parameter acquisition program to obtain the real-time transmission parameters of each channel. For each channel, the absolute difference between the measured value and the baseline value of each parameter is calculated one by one, and these absolute differences are summed. Then, the average value of all baseline values ​​is calculated as a reference for normalization. Dividing the summed absolute differences by the product of the total number of parameters and the average value of the baseline values ​​yields the parameter deviation for that channel. During the calculation process, it is necessary to ensure that the acquisition time of the real-time parameters and the baseline parameters are consistent to avoid errors in deviation calculation caused by time differences. The calculated parameter deviation is compared with a preset deviation threshold. If it exceeds the threshold, the channel is marked as an abnormal channel, and the specific deviation of the relevant parameters is recorded. This calculation method can comprehensively and objectively reflect the parameter deviation of each channel, uniformly quantifying the deviation of different types of parameters into a deviation degree. This allows staff to intuitively compare the operating status of each channel, quickly identify abnormal channels, provide accurate comparative data for the fault backtracking module, and improve the efficiency and accuracy of fault location. At the same time, the calculation process of this deviation degree is repeatable and consistent, ensuring that the deviation evaluation standard is uniform across different times and channels, providing a reliable guarantee for the stable operation of the system.

[0041] Preferably, the harmonic analysis and processing module includes a harmonic component extraction unit, a harmonic parameter calculation unit, a harmonic data integration unit, and a harmonic feature output unit. The harmonic component extraction unit receives channel quality assessment results, performs Fourier transform on the transmitted signals of each channel, decomposes the signals into components of different frequencies, and separates the fundamental component and each harmonic component. The harmonic parameter calculation unit analyzes each separated harmonic component, calculating the amplitude, phase, and frequency parameters of each harmonic. The amplitude is determined by calculating the ratio of the peak value to the effective value of the harmonic component, and the phase is determined by calculating the phase difference with the fundamental phase. The harmonic data integration unit sorts the parameters of each harmonic according to its harmonic order, forming a structured harmonic data set, and associates it with the corresponding channel identification information. The harmonic feature output unit performs format conversion on the integrated harmonic data set, generates harmonic analysis data that meets the input requirements of the forward-disturbance-reverse linkage detection module, and transmits it.

[0042] Specifically, the harmonic analysis and processing module comprises four units that work closely together to extract, analyze, and process harmonic components in the power distribution terminal channel signals, providing accurate harmonic characteristic data for subsequent modules. The harmonic component extraction unit, as the first step, focuses on decomposing complex signals into components of different frequencies. This process relies on a high-precision Fourier transform algorithm, converting the time-domain signal into a frequency-domain signal to effectively separate the fundamental wave from each harmonic. The unit's technical parameters include the number of transform points and frequency resolution. The number of transform points is typically set to 1024 to ensure a frequency resolution of 0.5Hz, enabling clear differentiation of adjacent harmonic components. In implementation, after receiving the channel quality assessment results, the unit prioritizes processing the channel signals that have passed the assessment. It performs Fourier transforms according to the set number of transform points, identifying and separating the fundamental wave and each harmonic one by one, laying the foundation for subsequent parameter calculations. The harmonic parameter calculation unit focuses on the specific characteristics of each harmonic. It acquires the amplitude, phase, and frequency of harmonics through dedicated measurement circuits. Amplitude measurement uses peak detection, with an error controlled within ±0.5%. Phase measurement, through comparison with the fundamental phase, achieves an accuracy of ±1°. Frequency measurement relies on a highly stable clock source, ensuring an error of no more than 0.1Hz. During implementation, the unit analyzes each separated harmonic component, performs a preliminary comparison of the calculated parameters with preset standard ranges, and identifies and marks abnormal harmonic parameters. The harmonic data integration unit systematizes the dispersed harmonic parameters, arranging them in ascending order of harmonic order, and associating them with corresponding channel numbers, acquisition times, and other identifying information to form a structured dataset. This unit has a data storage capacity of at least 1GB, meeting the harmonic data storage requirements for 24 consecutive hours. A circular storage mechanism is used during implementation; when storage space is insufficient, the oldest data is automatically overwritten. The harmonic feature output unit is responsible for data format conversion, transforming the integrated harmonic data into a format that conforms to the interface requirements of the forward-disturbance-reverse linkage detection module, typically the IEEE standard COMTRADE format, ensuring seamless data reception and processing. During implementation, the unit verifies the converted data, checking its integrity and format correctness before transmitting it to the next module. The collaborative operation of these four units realizes the entire process from harmonic extraction to feature output, providing high-quality harmonic data support for subsequent linkage detection and ensuring accurate identification of harmonic-related faults.

[0043] Preferably, the forward-disturbance-reverse linkage detection module includes a forward simulation unit, a disturbance coupling unit, a reverse fault-tolerant verification unit, and a linkage result generation unit. The forward simulation unit receives harmonic analysis data, establishes a normal operating state model based on the historical operating parameters of each channel of the power distribution terminal, inputs the harmonic analysis data into the model for simulation calculation, and generates a reference signal for each channel under normal conditions. The disturbance coupling unit calls the disturbance type and parameters from a preset disturbance parameter library, superimposes the disturbance parameters and the reference signal according to preset coupling rules, and generates a disturbance signal containing disturbance characteristics. The reverse fault-tolerant verification unit performs reverse deduction on the disturbance signal, and determines whether the disturbance signal can be corrected by the fault-tolerant mechanism during transmission by comparing the deviation between the deduction result and the reference signal, and records the signal change data during the fault-tolerant verification process. The linkage result generation unit integrates the reference signal from forward simulation, the disturbance signal from disturbance coupling, and the signal change data from reverse fault-tolerant verification to form a linkage detection result, which is then transmitted to the full-channel comparison module and the fault backtracking module, respectively.

[0044] Specifically, the four units of the forward-disturbance-reverse linkage detection module, and the functions and implementation methods of each unit in the detection process, comprehensively evaluate the channel's operational performance through a coherent operation of forward simulation, disturbance coupling, and reverse fault-tolerant verification. The forward simulation unit is the starting point of the entire detection process. Its core is to construct a reference signal that conforms to the actual operating state. This unit relies on a historical operating database, which stores the normal operating parameters of each channel over the past six months, covering signal characteristics under different loads and environmental conditions. In terms of technical parameters, the sampling frequency of the analog signal is consistent with the power distribution terminal, at 2kHz, and the signal duration is set to 5 minutes to include sufficient signal cycles. During implementation, after receiving harmonic analysis data, the unit extracts the key parameters of the fundamental and harmonic frequencies, combines them with similar operating condition data from the historical database, constructs a normal operating state model, inputs the parameters into the model for simulation calculation, and generates the reference signal. During the generation process, the amplitude, frequency, and other parameters of the signal are monitored in real time to ensure that their fluctuation range does not exceed ±2%. If it exceeds the range, the parameter weights in the model are adjusted, and the calculation is recalculated until the requirements are met. The function of the disturbance coupling unit is to introduce interference into the reference signal to simulate abnormal conditions in actual operation. This unit's disturbance parameter library contains 10 common disturbance types, such as voltage sags, frequency shifts, and harmonic injection, with each disturbance type corresponding to 3-5 different intensity levels. During implementation, the unit selects an appropriate disturbance type and intensity from the disturbance parameter library according to a preset detection strategy. For example, it selects a voltage sag disturbance, setting the sag amplitude to 10% and the duration to 0.5 seconds. The disturbance parameters are then superimposed on the reference signal according to a time sequence to generate a disturbance signal. During the superposition process, a synchronous triggering mechanism is used to ensure that the disturbance application time is accurate to the millisecond level, avoiding the influence of time deviation on the detection results. The reverse fault-tolerant verification unit is used to evaluate the channel's fault tolerance capability to disturbances. This unit is equipped with an analog transmission channel whose transmission characteristics are consistent with actual power distribution terminal channels, including parameters such as signal attenuation and delay. Technically, the verification sampling frequency is 4kHz, higher than the actual signal frequency, to capture subtle signal changes, and the fault tolerance judgment response time does not exceed 10ms. During implementation, the unit inputs the disturbance signal into the analog transmission channel, receives the transmitted signal, and compares it point-by-point with the reference signal to calculate the deviation value. For critical signal parameters, such as the effective values ​​of current and voltage, the deviation threshold is set to ±1%, while for general parameters it is set to ±3%. The verification is passed based on whether the deviation value is within the threshold range, and the signal fluctuation curve during the verification process is recorded in detail. The linkage result generation unit is responsible for integrating the data from each stage, summarizing the waveform data of the reference signal, the parameter configuration of the disturbance signal, and the deviation records of the fault tolerance verification, forming a linkage detection result containing more than 200 parameters. The data transmission rate of this unit is no less than 10Mbps to ensure that the results can be quickly transmitted to the full-channel comparison module and the fault backtracking module.During implementation, each unit performs a completeness check on the aggregated data, supplementing any missing key data using interpolation algorithms to ensure the completeness and accuracy of the results. The coordinated collaboration of these four units constructs a comprehensive, interconnected detection system. By simulating signal characteristics under various operating conditions, it comprehensively verifies the stability and fault tolerance of the channels, providing ample detection data for fault location.

[0045] Preferably, the full-channel comparison module includes a parameter acquisition unit, a reference parameter retrieval unit, a parameter comparison unit, and a comparison data output unit. The parameter acquisition unit collects the transmission parameters of each power distribution terminal channel in real time, including signal transmission rate, signal attenuation, and data integrity indicators, and marks the collected parameters according to timestamps. The reference parameter retrieval unit receives the linkage detection results from the forward-disturbance-reverse linkage detection module, extracts the reference parameters corresponding to each channel, establishes a reference parameter database, and associates it with the channel number. The parameter comparison unit compares the real-time parameters collected by the parameter acquisition unit with the reference parameters of the corresponding channels in the reference parameter database point by point, calculates the absolute deviation value and relative deviation value of each parameter, and marks the parameters that exceed the allowable deviation range. The comparison data output unit summarizes the deviation values, out-of-tolerance parameter identifiers, and corresponding channel information after comparison, generates channel comparison data, and transmits it to the fault backtracking module.

[0046] Specifically, the four units of the full-channel comparison module operate in the processes of parameter acquisition, benchmark retrieval, comparison analysis, and data output. Through high-precision parameter comparison, they provide accurate deviation data for fault tracing. The parameter acquisition unit is the data source, responsible for acquiring the transmission parameters of each channel in real time. This unit is equipped with multiple acquisition interfaces and can simultaneously acquire parameters from eight channels. Acquired parameters include signal transmission rate (unit: Mbps), signal attenuation (unit: dB), and data integrity index (unit: %). In terms of technical parameters, the acquisition frequency is set to once per minute to ensure timely capture of parameter changes, with an acquisition accuracy of 0.1%. The measurement error of signal transmission rate does not exceed 0.01 Mbps, and the measurement error of signal attenuation is controlled within ±0.1 dB. During implementation, the unit establishes a connection with the power distribution terminal through a communication interface and cyclically acquires parameters according to the set frequency. After each set of data is acquired, a timestamp accurate to milliseconds is immediately added and stored in a temporary cache with a capacity of 64 MB, which can temporarily store 24 hours of acquired data. The baseline parameter retrieval unit provides a reference standard for comparison. This unit maintains real-time communication with the forward-disturbance-reverse linkage detection module. Upon generation of the linkage detection results, it immediately extracts the baseline parameters for each channel, including baseline transmission rate, baseline attenuation, and baseline integrity indicators, to construct a baseline parameter database. The database employs a distributed storage architecture with a capacity of at least 500GB, supports concurrent reading, and has a response time of no more than 100ms. In implementation, the unit categorizes and stores baseline parameters according to channel number, performs hourly database backups to prevent data loss, and periodically synchronizes data with the linkage detection module to ensure the timeliness of the baseline parameters. The parameter comparison unit is the core of the entire module, responsible for calculating the deviation between real-time parameters and baseline parameters. This unit uses a dedicated comparison algorithm, supports multi-parameter parallel calculation, and can complete 100 parameter comparisons per second. Technically, the deviation calculation accuracy reaches 0.01%, capable of identifying minute parameter changes, and the response time for out-of-tolerance judgment is no more than 50ms. During implementation, the unit retrieves real-time parameters from a temporary cache and simultaneously obtains the corresponding channel's baseline parameters from the baseline database. It calculates the absolute and relative deviations for each parameter type. For example, for transmission rate, if the real-time value is 10.2 Mbps and the baseline value is 10 Mbps, the absolute deviation is 0.2 Mbps and the relative deviation is 2%. The relative deviation is compared to a preset threshold (transmission rate threshold is ±5%). If it exceeds the threshold, it is marked as an out-of-tolerance parameter, and the time and specific value of the out-of-tolerance are recorded. The comparison data output unit is responsible for organizing and outputting the comparison results. This unit supports multiple data format outputs, including CSV and XML, to meet the different data requirements of the fault backtracking module. Technically, the data output rate is no less than 5 Mbps to ensure rapid transmission of large amounts of comparison data, achieving 100% accuracy in the output data with no errors or omissions.During implementation, the unit prioritizes processing the marked out-of-tolerance parameters, integrating them with corresponding channel information, timestamps, and deviation values ​​to form structured channel comparison data. This data is validated before output to check the correctness of the data format and content. After validation, it is transmitted to the fault backtracking module, and the complete comparison results are stored on a local server for at least 30 days for subsequent query and analysis. The collaborative work of these four units achieves fully automated comparison from parameter acquisition to result output, providing accurate and detailed deviation data for fault backtracking and ensuring rapid location of abnormal channels.

[0047] The longitudinal differential protection and channel quality identification algorithm is the core algorithm in this invention used to evaluate the transmission quality of distribution terminal channels and the protection action criteria. Specifically, it combines the current and voltage signals of each channel in the distribution terminal with channel transmission parameters to comprehensively evaluate the channel's operating status and transmission quality. In terms of implementation, the longitudinal differential protection module first collects the current and voltage signals of each channel in real time, calculates the current difference and voltage difference, and generates a longitudinal differential protection action criterion signal. This signal reflects whether there are potential faults such as short circuits or overloads in the channel. Subsequently, the channel quality identification module receives this criterion signal and, combined with parameters such as signal transmission delay, bit error rate, and signal strength of each channel, performs quantitative analysis on these parameters through specific algorithmic logic to calculate a comprehensive channel quality evaluation value. The calculation of the current difference and voltage difference is based on the rated value, with corresponding threshold ranges set. When the threshold is exceeded, the protection action criterion is triggered. The channel quality evaluation is obtained by comparing the transmission delay, bit error rate, and signal strength with their respective thresholds, combined with weight allocation, to arrive at a comprehensive evaluation result. The algorithm provides initial protection data and channel quality references for subsequent harmonic analysis and linkage detection, ensuring the system can promptly identify suspected channel faults and transmission quality issues. Its significance lies in combining the electrical quantity analysis of longitudinal differential protection with channel transmission quality assessment, overcoming the limitations of single-parameter detection and achieving multi-dimensional evaluation of channel operating status. This lays the foundation for accurate detection in the entire automated testing system, improving the system's fault prediction capabilities and reliability.

[0048] The harmonic analysis model is the key model in this invention used to analyze harmonic components in the power distribution terminal channel signal. Specifically, it extracts, calculates parameters, and analyzes the characteristics of the fundamental wave and each harmonic in the channel transmission signal to quantitatively assess the degree of harmonic interference on signal transmission. In terms of implementation, firstly, the harmonic component extraction unit performs a Fourier transform on the received signal, converting the time-domain signal into a frequency-domain signal, thereby separating the fundamental wave component and each harmonic component. The number of transform points is typically set to 1024 points to ensure a frequency resolution of 0.5Hz. Next, the harmonic parameter calculation unit analyzes the separated harmonic components, using peak detection to measure the harmonic amplitude, with an error controlled within ±0.5%. The phase difference is obtained by comparing it with the fundamental wave phase, achieving an accuracy of ±1°. Frequency is measured using a high-stability clock source, with an error not exceeding 0.1Hz. Then, the harmonic data integration unit sorts these parameters by harmonic order, associates them with channel identifiers and acquisition time, forming a structured dataset with a storage capacity of no less than 1GB, employing a circular storage mechanism to meet 24-hour data requirements. Finally, the harmonic characteristic output unit converts the integrated data into the IEEE standard COMTRADE format, verifies it, and then transmits it to the next module. The model's function is to provide detailed harmonic characteristic data for the forward-disturbance-reverse linkage detection module, enabling the linkage detection to specifically simulate the channel state under harmonic interference. Its significance lies in accurately quantifying the degree of harmonic interference, helping the system identify channel anomalies caused by harmonics, improving the detection accuracy of harmonic-related faults, and ensuring the accuracy and stability of signal transmission in the power distribution terminal.

[0049] The integrated forward simulation-disturbance coupling-reverse fault tolerance detection algorithm is the core algorithm in this invention used to comprehensively evaluate the operating performance of power distribution terminal channels under different operating conditions. Specifically, it involves a coherent process of generating a reference signal through forward simulation, applying a disturbance to generate a disturbance signal, and then using reverse fault tolerance verification to assess the channel's fault tolerance capability, thereby detecting the channel's stability and anti-interference ability. In terms of implementation, the forward simulation unit relies on a historical database containing parameters from the past six months of normal operation, combined with harmonic analysis data to construct a model, generating a 5-minute reference signal at a 2kHz sampling frequency, ensuring that parameter fluctuations do not exceed ±2%. The disturbance coupling unit selects the type and intensity from a parameter library containing 10 disturbance types, such as a 10% voltage sag lasting 0.5 seconds, and superimposes the disturbance with the reference signal through a synchronous triggering mechanism to generate a disturbance signal. The reverse fault tolerance verification unit inputs the disturbance signal into the analog transmission channel, collects the transmitted signal at a 4kHz sampling frequency, compares it with the reference signal, sets the deviation threshold for key parameters to ±1%, and for general parameters to ±3%, with a response time not exceeding 10ms, and records the fluctuation curve. Finally, the linkage result generation unit integrates the data to form a detection result containing over 200 parameters, transmitted at a rate of no less than 10Mbps. The algorithm simulates various normal and abnormal operating conditions to comprehensively test the channel's operational performance and fault tolerance, providing crucial detection data for full-channel comparison and fault backtracking. Its significance lies in constructing a complete linkage detection system, overcoming the limitations of static detection, realizing the evaluation of channel dynamic performance, improving the system's ability to identify complex faults and its reliability, providing rich evidence for fault location, and ensuring the stable operation of the power distribution terminal in actual operation.

[0050] like Figure 2 As shown, the automated testing system for full-channel comparison and fault backtracking of power distribution terminals includes the following steps in its operation: Step S1: Continuously monitor the current and voltage signals of each channel of the power distribution terminal through the longitudinal differential protection module, calculate the current difference and voltage difference and generate the corresponding protection action criterion signal; Step S2: Transmit the protection action criterion signal to the channel quality identification module. Combine the signal transmission delay, bit error rate, and signal strength parameters of each channel, use the longitudinal differential protection and channel quality identification algorithm to quantitatively evaluate the transmission quality of each channel and output the evaluation results. Step S3: Transmit the evaluation results to the harmonic analysis and processing module, extract the harmonic components in each channel signal, calculate the harmonic amplitude, phase and order through the harmonic analysis model, and output the harmonic analysis data; Step S4: Transmit the harmonic analysis data to the forward-disturbance-reverse linkage detection module. First, generate a reference signal through forward simulation, then apply a preset disturbance to generate a disturbance signal, and finally perform reverse fault tolerance verification to generate the linkage detection result. Step S5: Transmit the linkage detection results to the full-channel comparison module, compare them one by one with the real-time transmission parameters of each channel, calculate the parameter deviation value and output the channel comparison data. Step S6: Transmit the linkage detection results and channel comparison data to the fault backtracking module. Based on the over-threshold deviation value and disturbance response characteristics, locate the fault channel location and time node and output fault backtracking information.

[0051] This automated testing system for full-channel comparison and fault tracing of power distribution terminals boasts the primary advantage of deep integration of multiple technologies and efficient collaboration of multiple modules, comprehensively overcoming the limitations of existing single-mode detection technologies. Through the tight connection of the longitudinal differential protection module and the channel quality identification module, it combines current and voltage signal analysis with channel transmission quality assessment. Furthermore, with the precise analysis of harmonic components by the harmonic analysis and processing module, a comprehensive evaluation system covering multiple dimensions such as signal characteristics, transmission quality, and harmonic interference is formed. This integrated approach changes the situation where each detection link is independent in existing technologies, enabling a comprehensive scan of the channel's operating status. This effectively overcomes the shortcomings of single algorithms or independent modules that can only perform localized detection and are unable to handle complex faults.

[0052] Secondly, the system innovatively adopts a forward simulation-disturbance coupling-reverse fault tolerance integrated linkage detection mechanism, which significantly improves the accuracy of fault identification and location. The forward-disturbance-reverse linkage detection module first simulates the normal state to generate a reference signal, then applies a disturbance to generate a disturbance signal, and finally captures the signal response characteristics through reverse fault tolerance verification. This process completely restores the channel's operating characteristics under different working conditions. Combined with the full-channel comparison module's detailed comparison of real-time parameters with reference parameters, and the fault backtracking module's correlation analysis of over-threshold deviation and disturbance response, the system can accurately pinpoint the channel location and time of the fault, solving the problem of lagging fault backtracking and correlation analysis relying on single parameters or simple logic in existing technologies.

[0053] Furthermore, the system significantly improves the timeliness and reliability of fault handling through the orderly connection of its modules and the efficient flow of data. The action criteria generated by the longitudinal differential protection module provide the initial basis for subsequent detection, the channel quality assessment results guide the focus of harmonic analysis, and the linkage detection results provide key references for full-channel comparison and fault backtracking. Data is seamlessly transmitted and mutually supportive at each stage. This efficient collaborative mechanism ensures efficient operation throughout the entire process from signal acquisition, analysis and evaluation to fault location. Compared with the lag in data processing and information transmission of existing technologies, it can respond to channel anomalies more quickly, providing a more solid technical guarantee for the stable operation of the power system.

[0054] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0055] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various equivalent changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automated testing system for full-channel comparison and fault tracing of power distribution terminals, characterized in that, include: Longitudinal differential protection module, channel quality identification module, harmonic analysis and processing module, forward-disturbance-reverse linkage detection module, full-channel comparison module, and fault backtracking module; The output of the longitudinal differential protection module is connected to the input of the channel quality identification module. The output of the channel quality identification module is connected to the input of the harmonic analysis and processing module. The output of the harmonic analysis and processing module is connected to the input of the forward-disturbance-reverse linkage detection module. The output of the forward-disturbance-reverse linkage detection module is connected to the input of the full-channel comparison module and the first input of the fault backtracking module, respectively. The output of the full-channel comparison module is connected to the second input of the fault backtracking module. The longitudinal differential protection module is based on the real-time current and voltage signals transmitted by each channel of the power distribution terminal. The system generates a longitudinal differential protection action criterion signal by calculating the current and voltage differences between each channel. The channel quality identification module receives the longitudinal differential protection action criterion signal and, in conjunction with the signal transmission delay, bit error rate, and signal strength parameters of each channel, performs a quantitative evaluation of the transmission quality of each channel using the longitudinal differential protection and channel quality identification algorithm, outputting the channel quality evaluation result. The harmonic analysis and processing module receives the channel quality evaluation result, extracts the harmonic components in the transmitted signals of each channel, calculates the harmonic amplitude, phase, and harmonic order using a harmonic analysis model, and outputs harmonic analysis data.

2. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, The forward-disturbance-reverse linkage detection module receives harmonic analysis data and adopts a forward simulation-disturbance coupling-reverse fault tolerance integrated linkage detection algorithm. First, it performs forward simulation on the normal operation state of each channel to generate a reference signal. Then, it applies a preset disturbance to the reference signal to generate a disturbance signal. Finally, it performs reverse fault tolerance verification on the disturbance signal to generate linkage detection results. The full-channel comparison module receives the linkage detection results, compares the real-time transmission parameters of each channel with the benchmark parameters in the linkage detection results one by one, calculates the parameter deviation value, and outputs the channel comparison data. The fault backtracking module receives the linkage detection results and channel comparison data. Based on the deviation value exceeding the preset threshold in the channel comparison data, combined with the disturbance response characteristics in the linkage detection results, it locates the channel location and time node where the fault occurred and outputs fault backtracking information. When the longitudinal differential protection module and the channel quality identification module work together, the comprehensive channel quality assessment value is calculated using the following model formula: in, This is a comprehensive evaluation value for channel quality. The weighting coefficients and , This is the measured value of the longitudinal differential current. The threshold value for setting the longitudinal differential current is... This is the measured value of signal transmission delay. This is the allowable threshold for signal transmission delay. This is the measured bit error rate. This represents the maximum permissible bit error rate.

3. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, When the harmonic analysis and processing module processes harmonic components using a harmonic analysis model, it calculates the harmonic distortion rate using the following model formula: in, Total harmonic distortion (THD) For harmonic order, The highest harmonic order, For the first The amplitude of the second harmonic. This represents the amplitude of the fundamental frequency.

4. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, During the forward simulation process, the forward-disturbance-reverse linkage detection module generates a reference signal using the following model formula: in, for The reference signal at time, for The original input signal at time 10:

00. Number the influencing factors. The total number of influencing factors. for Time of the first Signal bias caused by various influencing factors For the first Correction coefficients for each influencing factor.

5. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, The forward-disturbance-reverse linkage detection module generates a disturbance signal during the disturbance coupling process using the following model formula: in, for The disturbance signal at any given moment. for The reference signal at time, For the disturbance amplitude coefficient, The perturbation angular frequency, This represents the initial phase of the disturbance.

6. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, When performing parameter comparison, the full-channel comparison module calculates the channel parameter deviation using the following model formula: in, For the first The parameter deviation of each channel As parameter number, For the total number of parameters, For the first The first channel Measured values ​​of each parameter For the first The baseline values ​​for each parameter, This is the average of the baseline values ​​for all parameters.

7. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, The harmonic analysis and processing module includes a harmonic component extraction unit, a harmonic parameter calculation unit, a harmonic data integration unit, and a harmonic feature output unit. The harmonic component extraction unit receives the channel quality assessment results, performs Fourier transform on the transmitted signals of each channel, decomposes the signals into components of different frequencies, and separates the fundamental component and each harmonic component from them. The harmonic parameter calculation unit analyzes the separated harmonic components and calculates the amplitude, phase, and frequency parameters of each harmonic. The amplitude is determined by calculating the ratio of the peak value to the effective value of the harmonic component, and the phase is determined by calculating the phase difference by comparing it with the fundamental phase. The harmonic data integration unit sorts the parameters of each harmonic according to the harmonic order to form a structured harmonic data set, and associates it with the corresponding channel identification information. The harmonic feature output unit converts the format of the integrated harmonic data set, generates harmonic analysis data that meets the input requirements of the forward-disturbance-reverse linkage detection module, and transmits it.

8. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, The forward-disturbance-reverse linkage detection module includes a forward simulation unit, a disturbance coupling unit, a reverse fault-tolerant verification unit, and a linkage result generation unit. The forward simulation unit receives harmonic analysis data, establishes a normal operating state model based on the historical operating parameters of each channel of the power distribution terminal, inputs the harmonic analysis data into the model for simulation calculation, and generates a reference signal for each channel under normal conditions. The disturbance coupling unit calls disturbance types and parameters from a preset disturbance parameter library, superimposes the disturbance parameters and the reference signal according to preset coupling rules, and generates a disturbance signal containing disturbance characteristics. The reverse fault-tolerant verification unit performs reverse deduction on the disturbance signal, and determines whether the disturbance signal can be corrected by the fault-tolerant mechanism during transmission by comparing the deviation between the deduction result and the reference signal, and records the signal change data during the fault-tolerant verification process. The linkage result generation unit integrates the reference signal from forward simulation, the disturbance signal from disturbance coupling, and the signal change data from reverse fault-tolerant verification to form a linkage detection result, which is then transmitted to the full-channel comparison module and the fault backtracking module, respectively.

9. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to claim 1, characterized in that, The full-channel comparison module includes a parameter acquisition unit, a reference parameter retrieval unit, a parameter comparison unit, and a comparison data output unit. The parameter acquisition unit collects the transmission parameters of each power distribution terminal channel in real time, including signal transmission rate, signal attenuation, and data integrity indicators, and marks the collected parameters according to timestamps. The reference parameter retrieval unit receives the linkage detection results from the forward-disturbance-reverse linkage detection module, extracts the reference parameters corresponding to each channel, establishes a reference parameter database, and associates them with the channel numbers. The parameter comparison unit compares the real-time parameters collected by the parameter acquisition unit with the reference parameters of the corresponding channels in the reference parameter database point by point, calculates the absolute deviation value and relative deviation value of each parameter, and marks the parameters that exceed the allowable deviation range. The comparison data output unit summarizes the deviation values, out-of-tolerance parameter identifiers, and corresponding channel information after comparison, generates channel comparison data, and transmits it to the fault backtracking module.

10. The automated testing system for full-channel comparison and fault tracing of power distribution terminals according to any one of claims 1-9, characterized in that, The system operation includes the following steps: Step S1: Continuously monitor the current and voltage signals of each channel of the power distribution terminal through the longitudinal differential protection module, calculate the current difference and voltage difference and generate the corresponding protection action criterion signal; Step S2: Transmit the protection action criterion signal to the channel quality identification module. Combine the signal transmission delay, bit error rate, and signal strength parameters of each channel, use the longitudinal differential protection and channel quality identification algorithm to quantitatively evaluate the transmission quality of each channel and output the evaluation results. Step S3: Transmit the evaluation results to the harmonic analysis and processing module, extract the harmonic components in each channel signal, calculate the harmonic amplitude, phase and order through the harmonic analysis model, and output the harmonic analysis data; Step S4: Transmit the harmonic analysis data to the forward-disturbance-reverse linkage detection module. First, generate a reference signal through forward simulation, then apply a preset disturbance to generate a disturbance signal, and finally perform reverse fault tolerance verification to generate the linkage detection result. Step S5: Transmit the linkage detection results to the full-channel comparison module, compare them one by one with the real-time transmission parameters of each channel, calculate the parameter deviation value and output the channel comparison data. Step S6: Transmit the linkage detection results and channel comparison data to the fault backtracking module. Based on the over-threshold deviation value and disturbance response characteristics, locate the fault channel location and time node and output fault backtracking information.

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