A relay protection device automatic test system and a test method thereof

Abstract

This application relates to the field of relay protection device testing technology, and proposes an automatic testing system and method for relay protection devices, including: acquiring the three-phase current and three-phase voltage of the relay protection device from the output port of the tester; marking the target current phase protection current and the target current phase test current, and calculating the single-phase correction factor of the target current phase protection current; selecting the target current phase and the comparison current phase from the three-phase current, and calculating the phase-to-phase correction factor between the target current phase and the comparison current phase; calculating the correction value of the current of the target current phase to complete the correction of the three-phase current; realizing the correction of the three-phase voltage based on the output port of the tester and the three-phase voltage of the relay protection device; and completing the testing of the relay protection device based on the corrected current and voltage. This application can improve the accuracy of the performance evaluation results of relay protection devices.

Description

Technical Field

[0001] This application relates to the field of relay protection device testing technology, specifically to an automatic testing system and testing method for relay protection devices. Background Technology

[0002] Relay protection devices are core safety protection equipment in substations, capable of rapidly responding to power grid faults and executing protective actions. Their reliability and accuracy are key indicators for ensuring the safe operation of substations; therefore, comprehensive and accurate performance testing must be conducted before commissioning. Evaluation of test results is a crucial step in relay protection automation testing, directly determining the accuracy of device performance assessment. Current general testing standards clearly stipulate that the operating time error of relay protection devices must be controlled within ±1% of the calibrated value, and the amplitude accuracy error of current, voltage, and other protection actions must be controlled within ±5% of the calibrated value. The fault recording module inside the relay protection device can collect waveform data before and after a fault, and through data analysis and calculation, obtain the protection action value to complete performance assessment.

[0003] However, the fault simulation data used in the test contains a large number of high-frequency transient components. These components can cause magnetic saturation in the test circuit, interfering with the data acquisition process of the fault recording module and resulting in distortion and deformation of the acquired waveform data. Distorted data cannot accurately reflect the operating status of the device under fault conditions, significantly reducing the calculation accuracy of protection action values, causing distortion in the performance evaluation results of the relay protection device, and making it impossible to accurately determine the actual working performance of the device. Summary of the Invention

[0004] This application provides an automatic testing system and method for relay protection devices to solve the problem that the high-frequency transient components of fault simulation data cause data distortion in relay protection testing, leading to inaccurate performance evaluation results of relay protection devices. The specific technical solution adopted is as follows:

[0005] In a first aspect, one embodiment of this application provides an automatic testing method for a relay protection device, the method comprising the following steps:

[0006] Collect the three-phase current and three-phase voltage of the tester output port and the relay protection device within a preset time period before the relay protection device performs its protection action;

[0007] The current of any phase of the relay protection device is recorded as the target phase protection current. The current of the tester output port that is in the same phase as the target phase protection current is recorded as the target phase test current. Any acquisition time is recorded as the target acquisition time. A time window for the target acquisition time is constructed. Based on the difference in amplitude of the target phase test current and the difference in amplitude of the target phase protection current within the time window of the target acquisition time, the single-phase correction factor of the target phase protection current at the target acquisition time is calculated.

[0008] Select the target current phase and the comparison current phase in the three-phase current. Based on the difference between the current at the output port of the tester and the current of the relay protection device in the same phase within the time window of the target acquisition time, calculate the current difference of the same phase at the target acquisition time. Combine the correlation of the current differences of the target current phase and the comparison current phase at each acquisition time within the time window of the target acquisition time, calculate the phase correction factor between the target current phase and the comparison current phase at the target acquisition time.

[0009] Based on the value of the target current phase protection current at the target acquisition time, the single-phase correction factor of the target current phase protection current, and the phase-to-phase correction factor between the target current phase and the comparison current phase, the correction value of the target current phase current at the target acquisition time is calculated to complete the correction of the three-phase current. Based on the output port of the tester and the three-phase voltage of the relay protection device, the correction of the three-phase voltage is realized. Based on the corrected current and voltage, the test of the relay protection device is completed.

[0010] Furthermore, the specific method for calculating the single-phase correction factor of the target current phase protection current at the target acquisition time based on the difference in amplitude of the target current phase test current and the difference in amplitude of the target current phase protection current within the time window of the target acquisition time includes:

[0011] Based on the difference in amplitude between the target current phase test current and the target current phase protection current within the time window of the target acquisition time, the local energy deviation of the target current phase protection current at the target acquisition time is calculated.

[0012] Based on the first-order forward difference of the amplitudes of the target current phase test current and the target current phase protection current within the time window of the target acquisition time, calculate the local fluctuation deviation of the target current phase protection current at the target acquisition time.

[0013] The weighted sum of the local energy deviation and local fluctuation deviation of the target current phase protection current at the target acquisition time is denoted as the single-phase correction factor of the target current phase protection current at the target acquisition time, and the weighted sum of the local energy deviation and local fluctuation deviation is 1.

[0014] Furthermore, the local energy deviation of the target current phase protection current at the target acquisition time is: the ratio of the root mean square of the amplitude of the target current phase test current to the root mean square of the amplitude of the target current phase protection current within the time window of the target acquisition time.

[0015] Furthermore, the specific calculation method for the local fluctuation deviation of the target current phase protection current at the target acquisition time is as follows:

[0016] Calculate the mean absolute value of the first forward difference of the amplitude of the target current phase test current within the time window of the target acquisition time, and the mean absolute value of the first forward difference of the amplitude of the target current phase protection current within the time window of the target acquisition time. Record these as the first mean and the second mean within the time window of the target acquisition time. Record the ratio of the first mean to the second mean within the time window of the target acquisition time as the local fluctuation deviation of the target current phase protection current at the target acquisition time.

[0017] Furthermore, the current difference of the same phase at the target acquisition time is: the difference between the current at the output port of the tester at the target acquisition time and the current of the same phase of the relay protection device.

[0018] Furthermore, the method for calculating the inter-phase correction factor between the target current phase and the comparison current phase at the target acquisition time is as follows:

[0019] Based on the current difference between the target current phase and the comparison current phase at all acquisition times within the time window of the target acquisition time, calculate the error synchronization index between the target current phase and the comparison current phase at the target acquisition time.

[0020] The difference between the absolute values ​​of the current differences between the comparison current phase and the target current phase at the target acquisition time and the maximum value of the number 0 are selected and denoted as the interphase coupling transmission error between the target current phase and the comparison current phase at the target acquisition time. The product of the interphase coupling transmission error between the target current phase and the comparison current phase at the target acquisition time and the error synchronization index is denoted as the interphase correction factor between the target current phase and the comparison current phase at the target acquisition time.

[0021] Furthermore, the specific method for determining the error synchronization index between the target current phase and the comparison current phase at the target acquisition time is as follows:

[0022] Establish the current difference sequence of each current phase at the target acquisition time, and denote the absolute value of the Pearson correlation coefficient between the current difference sequences of the target current phase and the comparison current phase at the target acquisition time as the error synchronization index between the target current phase and the comparison current phase at the target acquisition time.

[0023] Furthermore, the method for calculating the correction value of the target current phase at the target acquisition time is as follows:

[0024] Based on the numerical relationship between the target current phase protection current and the digital 0 at the target acquisition time, the data polarity coefficient of the target current phase at the target acquisition time is assigned to 1, -1 or 0; combined with the phase-to-phase correction factor of the target current phase and the comparison current phase at the target acquisition time, the phase-to-phase correction value of the target current phase at the target acquisition time is calculated.

[0025] The sum of the product of the single-phase correction factor of the target current phase protection current at the target acquisition time and the target current phase protection current and the phase-to-phase correction value is used as the correction value of the target current phase current at the target acquisition time.

[0026] Furthermore, the phase correction value of the target current phase at the target acquisition time is: the product of the average of the phase correction factors of the target current phase and the two comparison current phases at the target acquisition time and the data polarity coefficient of the target current phase at the target acquisition time.

[0027] Secondly, embodiments of this application also provide an automatic testing system for relay protection devices, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of any of the methods described above.

[0028] The beneficial effects of this application are:

[0029] This application, based on the characteristic that the transient components of fault simulation electrical quantity signals cause differences between the test current and the protection current of the target current phase, calculates the single-phase correction factor of the protection current of the target current phase at the target acquisition time, based on amplitude attenuation loss and waveform attenuation distortion. Due to the influence of inter-phase electromagnetic coupling of the fault signal, the fault waveform data includes errors from the single-phase sampling link itself, and is further compounded by additional errors from inter-phase coupling crosstalk. Therefore, by quantifying the response correlation and response error amplitude between each phase electrical quantity signal, the inter-phase correction factor between the target current phase and the comparison current phase at the target acquisition time is calculated. The larger the inter-phase correction factor between the target current phase and the comparison current phase at the target acquisition time, the better the synchronization and phase relationship of the current errors within the time window of the comparison current phase and the target current phase at the target acquisition time. The greater the degree of correction and adjustment of the target current phase current due to the inter-coupling conduction error, the more significant the waveform distortion effect caused by the fault transient component will be. Therefore, based on the value of the target current phase protection current at the target acquisition time, the single-phase correction factor of the target current phase protection current, and the inter-phase correction factor between the target current phase and the comparison current phase, the correction value of the target current phase current at the target acquisition time is calculated to complete the correction of the three-phase current. At the same time, based on the output port of the tester and the three-phase voltage of the relay protection device, the correction of the three-phase voltage is realized. Based on the corrected current and voltage, the test of the relay protection device is completed, solving the problem that the high-frequency transient component of the fault contained in the fault analog data distorts the data acquired by the relay protection test, resulting in the distortion of the performance evaluation results of the relay protection device. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating an automatic testing method for a relay protection device provided in one embodiment of this application. Detailed Implementation

[0031] Please see Figure 1 The diagram illustrates an automatic testing method for a relay protection device according to an embodiment of this application. The method includes the following steps:

[0032] Step S001: Collect the three-phase current and three-phase voltage of the tester output port and the relay protection device within a preset time period before the relay protection device performs its protection action.

[0033] After the relay protection device performs its protection action, the three-phase current and three-phase voltage will return to normal. Therefore, based on the automatic testing system for the relay protection device, the three-phase current and three-phase voltage of the tester output port, as well as the three-phase current and three-phase voltage of the relay protection device, are collected during a preset period before the relay protection device performs its protection action.

[0034] The preset time is an integer multiple of the frequency before the relay protection device performs the protection action. In this embodiment, the preset time is 60ms, which is 3 times the frequency of 20ms. In this embodiment, the sampling frequency of the tester output port and the three-phase current and three-phase voltage of the relay protection device are both set to 10kHz.

[0035] The three-phase current and three-phase voltage of the relay protection device are the fault recording data.

[0036] At this point, the three-phase current and three-phase voltage of the tester output port and the relay protection device are obtained.

[0037] Step S002: Record any phase current of the relay protection device as the target phase protection current, record the current at the output port of the tester that is in the same phase as the target phase protection current as the target phase test current, record any acquisition time as the target acquisition time, construct a time window for the target acquisition time, and calculate the single-phase correction factor of the target phase protection current at the target acquisition time based on the difference in amplitude of the target phase test current and the difference in amplitude of the target phase protection current within the time window of the target acquisition time.

[0038] During the testing of relay protection devices, the relay protection tester outputs fault simulation electrical quantity signals to the relay protection device. These signals include current and voltage information under both steady-state and fault conditions of the local substation lines, specifically three-phase current and three-phase voltage. The transition phase from fault occurrence to fault stabilization generates significant fault transient components, primarily consisting of high-frequency transient pulse components and DC attenuation components caused by sudden fault changes. These transient components are characterized by rapid amplitude changes and complex frequency compositions, and also exhibit three-phase electromagnetic coupling. When the transient signals corresponding to these components are fed into the internal sampling circuit of the relay protection device, they can easily cause magnetic saturation in the circuit's electromagnetic components. After magnetic saturation occurs, the amplitude of the secondary electrical quantity sampled by the device no longer increases linearly with the original electrical quantity output by the tester; instead, the amplitude gradually becomes constant or even decreases, causing weakening and clipping distortion in the fault waveform. Therefore, a data deviation occurs between the fault waveform data and the standard fault simulation electrical quantities. Relying on fault recording data with deviations, the operating current and operating voltage at the moment of protection action are calculated. However, the calculation results also have errors and cannot truly reflect the actual action response characteristics of the relay protection device. At the same time, when comparing the calculated action quantity with the device setting value, it is difficult to achieve an accurate assessment of the true performance of the relay protection device.

[0039] The current of any one phase in the three-phase current of the relay protection device is recorded as the target phase protection current. The current in the three-phase current at the output port of the tester that is in the same phase as the target phase protection current is recorded as the target phase test current. Any acquisition time is recorded as the target acquisition time. A time window of a preset length is established with the target acquisition time as the center. The ratio of the root mean square of the amplitude of the target phase test current to the root mean square of the amplitude of the target phase protection current within the time window of the target acquisition time is recorded as the local energy deviation of the target phase protection current at the target acquisition time.

[0040] The length of the time window for the target phase current should be an odd number that is greater than or equal to 5 and less than or equal to 11. Considering the presence of local abnormal noise disturbances and zero-crossing data in the target phase current, this embodiment sets the preset length to 7.

[0041] The fault transient component contained in the fault simulation electrical quantity signal will cause a difference between the target current phase test current and the target current phase protection current. When the local energy deviation is greater than 1 and the larger the value, the greater the amplitude attenuation loss of the corresponding target current phase protection current due to the transient component, and the more amplitude compensation should be applied to the target current phase protection current.

[0042] Calculate the mean absolute value of the first forward difference of the amplitude of the target current phase test current within the time window of the target acquisition time, and the mean absolute value of the first forward difference of the amplitude of the target current phase protection current within the time window of the target acquisition time. Record these as the first mean and the second mean within the time window of the target acquisition time. Record the ratio of the first mean to the second mean within the time window of the target acquisition time as the local fluctuation deviation of the target current phase protection current at the target acquisition time.

[0043] Local fluctuation deviation is used to evaluate the difference in dynamic change capability between the target current phase test current and the target current phase protection current within a time window. When the local fluctuation deviation is greater than 1 and the larger the value, the greater the fluctuation rate of the target current phase test current is than that of the target current phase protection current. The waveform attenuation and distortion of the target current phase protection current caused by transient components are more significant, and more compensation should be applied to the target current phase protection current.

[0044] Specifically, when the second mean is equal to 0, the corresponding local fluctuation deviation is directly assigned the value of 0.

[0045] The weighted sum of the local energy deviation and local fluctuation deviation of the target current phase protection current at the target acquisition time is denoted as the single-phase correction factor of the target current phase protection current at the target acquisition time. The weighted sum of the local energy deviation and local fluctuation deviation is 1. The formula for calculating the weight of the local energy deviation is:

[0046]

[0047] in, This indicates the order of the target acquisition time within a preset time period. This indicates that the target current phase protection current is within the preset time period. The weight of the local energy deviation at each acquisition moment; This indicates that the target current phase protection current is within the preset time period. The weight of local fluctuation deviation at each acquisition time; This indicates the total number of data collection moments within the preset time period.

[0048] As the fault develops, the influence of the fault transient component gradually stabilizes. The calculation method of the weights of local energy deviation and local fluctuation deviation can make the compensation correction gradually biased towards the local energy deviation of the target current phase protection current as the fault develops.

[0049] The same method can be used to obtain the single-phase correction factor of each phase current in the three-phase current of the relay protection device at each acquisition time within a preset period before the relay protection device performs the protection action.

[0050] Thus, the single-phase correction factor of each phase current of the relay protection device at each acquisition time is obtained.

[0051] Step S003: Select the target current phase and the comparison current phase among the three-phase currents. Based on the difference between the current at the output port of the tester and the current of the relay protection device in the same phase within the time window of the target acquisition time, calculate the current difference of the same phase at the target acquisition time. Combining the correlation of the current differences of the target current phase and the comparison current phase at each acquisition time within the time window of the target acquisition time, calculate the phase correction factor between the target current phase and the comparison current phase at the target acquisition time.

[0052] The fault recording function of relay protection devices samples the electrical quantities of each phase separately through independent channels. However, fault signals inherently suffer from inter-phase conducted coupling interference. When the electrical quantity of one phase fluctuates drastically, the transient coupling effect causes the other phases to respond synchronously. Due to the influence of inter-phase electromagnetic coupling of the fault signal, the fault recording data not only includes errors from the single-phase sampling link itself but also additional errors from inter-phase coupling crosstalk, resulting in deviations between the fault recording data and the three-phase current and three-phase voltage measured by the relay protection tester. Therefore, it is necessary to analyze the response correlation and response error amplitude between the electrical quantity signals of each phase to compensate for and correct the inter-phase coupling error. The electrical quantity signals include three-phase current and three-phase voltage.

[0053] The current phase corresponding to the test current of the target current phase is denoted as the target current phase. The difference between the current at the output port of the tester of the target current phase at the target acquisition time and the current of the relay protection device is denoted as the current difference of the target current phase at the target acquisition time. The current differences of all acquisition times within the time window of the target acquisition time are arranged in chronological order to obtain the current difference sequence of the target current phase at the target acquisition time.

[0054] The same method can be used to obtain the current difference sequence of each phase current at each sampling time within a preset period before the relay protection device performs the protection action.

[0055] The current of any phase that is different from the target current phase test current is denoted as the comparison current phase. The absolute value of the Pearson correlation coefficient of the current difference sequence between the target current phase and the comparison current phase at the target acquisition time is denoted as the error synchronization index between the target current phase and the comparison current phase at the target acquisition time.

[0056] The calculation of the Pearson correlation coefficient is a well-known technique and will not be elaborated further.

[0057] Errors generated by transient fault components can induce electromagnetic crosstalk of opposite polarity in adjacent phases through the common magnetic circuit, i.e., reverse mutual inductance. Therefore, in calculating the error synchronization index, the absolute value of the Pearson correlation coefficient is taken. The larger the error synchronization index, the stronger the consistency of error fluctuations between the target current phase and the comparison current phase, and the stronger the coupling interference between the target current phase and the comparison current phase.

[0058] The difference between the absolute values ​​of the current differences between the comparison current phase and the target current phase at the target acquisition time and the maximum value of the number 0 are selected and denoted as the interphase coupling transmission error between the target current phase and the comparison current phase at the target acquisition time. The product of the interphase coupling transmission error between the target current phase and the comparison current phase at the target acquisition time and the error synchronization index is denoted as the interphase correction factor between the target current phase and the comparison current phase at the target acquisition time.

[0059] When the difference between the current in the comparison current phase and the target current phase at the target acquisition time is greater than 0, the error amplitude in the comparison current phase is greater than the error amplitude in the target current phase. The comparison current phase is more likely to generate interphase coupling and conduction interference to the target current phase as a fault source. Based on the degree of conduction influence between the error in the comparison current phase and the error in the target current phase, the degree of correction and compensation for the target current phase should be greater.

[0060] The larger the phase-to-phase correction factor between the target current phase and the comparison current phase at the target acquisition time, the greater the degree of correction and adjustment of the current of the target current phase based on the synchronicity of the current error and the phase-to-phase coupling transmission error between the comparison current phase and the target current phase within the time window at the target acquisition time.

[0061] The same method can be used to obtain the phase correction factor for each pair of phases in the three-phase current at each acquisition time within a preset period before the relay protection device performs the protection action.

[0062] Thus, the phase correction factors for different phases in the three-phase current at each acquisition time are obtained.

[0063] Step S004: Based on the value of the target current phase protection current at the target acquisition time, the single-phase correction factor of the target current phase protection current, and the phase-to-phase correction factor between the target current phase and the comparison current phase, calculate the correction value of the current of the target current phase at the target acquisition time, complete the correction of the three-phase current, and realize the correction of the three-phase voltage based on the output port of the tester and the three-phase voltage of the relay protection device. Based on the corrected current and voltage, complete the test of the relay protection device.

[0064] The waveform distortion caused by the transient component of the fault varies depending on the current's polarity range. When the current is in the positive half-cycle of the waveform, the sampling polarity is positive, and the transient distortion reduces the current amplitude. When the current is in the negative half-cycle of the waveform, the sampling polarity is negative, and the current amplitude increases under the same distortion effect. Based on these characteristics, the data polarity coefficient is directly assigned a value to aid in the subsequent correction of the current value.

[0065] When the protection current of the target current phase is greater than 0 at the target acquisition time, the data polarity coefficient of the target current phase at the target acquisition time is assigned to 1; when the protection current of the target current phase is less than 0 at the target acquisition time, the data polarity coefficient of the target current phase at the target acquisition time is assigned to -1; when the protection current of the target current phase is equal to 0 at the target acquisition time, the data polarity coefficient of the target current phase at the target acquisition time is assigned to 0.

[0066] The product of the average of the interphase correction factors of the target current phase and the two comparison current phases at the target acquisition time and the data polarity coefficient of the target current phase at the target acquisition time is denoted as the interphase correction value of the target current phase at the target acquisition time; the sum of the product of the single-phase correction factor of the protection current of the target current phase at the target acquisition time and the protection current of the target current phase and the interphase correction value is taken as the correction value of the current of the target current phase at the target acquisition time.

[0067] The same method can be used to obtain the correction values ​​of the three-phase current at each sampling time within a preset period before the relay protection device performs the protection action, thereby realizing the correction of the three-phase current.

[0068] The method of correcting the three-phase current based on the output port of the tester and the three-phase current of the relay protection device is used to correct the three-phase voltage based on the output port of the tester and the three-phase voltage of the relay protection device. The specific steps are as follows.

[0069] The voltage of any one phase of the three-phase voltage of the relay protection device is recorded as the target phase protection voltage. The voltage of the same phase as the target phase protection voltage in the three-phase voltage of the tester output port is recorded as the target phase test voltage. The ratio of the root mean square of the amplitude of the target phase test voltage to the root mean square of the amplitude of the target phase protection voltage within the time window of the target acquisition time is recorded as the local energy deviation of the target phase protection voltage at the target acquisition time.

[0070] Calculate the mean absolute value of the first forward difference of the amplitude of the target phase test voltage and the mean absolute value of the first forward difference of the amplitude of the target phase protection voltage within the time window of the target acquisition time, respectively. Record these as the first mean and the second mean within the time window of the target acquisition time. Record the ratio of the first mean to the second mean within the time window of the target acquisition time as the local fluctuation deviation of the target phase protection voltage at the target acquisition time.

[0071] Specifically, when the second mean is equal to 0, the corresponding local fluctuation deviation is directly assigned the value of 0.

[0072] The weighted sum of the local energy deviation and local fluctuation deviation of the target phase protection voltage at the target acquisition time is denoted as the single-phase correction factor of the target phase protection voltage at the target acquisition time. The weighted sum of the local energy deviation and local fluctuation deviation is 1. The formula for calculating the weight of the local energy deviation is:

[0073]

[0074] in, This indicates that the target phase protection voltage is within the preset time period. The weight of the local energy deviation at each acquisition moment; This indicates that the target phase protection voltage is within the preset time period. The weight of local fluctuation deviation at each acquisition time.

[0075] The same method can be used to obtain the single-phase correction factor of each phase voltage in the three-phase voltage of the relay protection device at each acquisition time within a preset period before the relay protection device performs the protection action.

[0076] The voltage phase corresponding to the target voltage phase test voltage is denoted as the target voltage phase. The difference between the voltage at the output port of the tester of the target voltage phase at the target acquisition time and the voltage of the relay protection device is denoted as the voltage difference of the target voltage phase at the target acquisition time. The voltage differences of all acquisition times within the time window of the target acquisition time are arranged in chronological order to obtain the voltage difference sequence of the target voltage phase at the target acquisition time.

[0077] The same method can be used to obtain the voltage difference sequence of each phase voltage at each sampling time within a preset period before the relay protection device performs the protection action.

[0078] The voltage of any phase that is different from the target voltage phase is denoted as the comparison voltage phase. The absolute value of the Pearson correlation coefficient of the voltage difference sequence between the target voltage phase and the comparison voltage phase at the target acquisition time is denoted as the error synchronization index between the target voltage phase and the comparison voltage phase at the target acquisition time.

[0079] The maximum value between the voltage difference between the comparison voltage phase and the target voltage phase at the target acquisition time and the digit 0 is selected and denoted as the interphase coupling conduction error between the target voltage phase and the comparison voltage phase at the target acquisition time. The relationship between the interphase coupling conduction error between the target voltage phase and the comparison voltage phase at the target acquisition time and the error synchronization index is denoted as the interphase correction factor between the target voltage phase and the comparison voltage phase at the target acquisition time.

[0080] The same method can be used to obtain the phase correction factor for each pair of phases in the three-phase voltage at each sampling time within a preset period before the relay protection device performs the protection action.

[0081] When the protection voltage of the target phase at the target acquisition time is greater than 0, the data polarity coefficient of the target phase at the target acquisition time is assigned a value of 1; when the protection voltage of the target phase at the target acquisition time is less than 0, the data polarity coefficient of the target phase at the target acquisition time is assigned a value of -1; when the protection voltage of the target phase at the target acquisition time is equal to 0, the data polarity coefficient of the target phase at the target acquisition time is assigned a value of 0.

[0082] The product of the average of the phase-to-phase correction factors of the target phase and the two comparison phases at the target acquisition time and the data polarity coefficient of the target phase at the target acquisition time is recorded as the phase-to-phase correction value of the target phase at the target acquisition time; the sum of the product of the single-phase correction factor of the target phase protection voltage at the target acquisition time and the target phase protection voltage and the phase-to-phase correction value is used as the correction value of the voltage of the target phase at the target acquisition time.

[0083] The same method can be used to obtain the correction values ​​of the three-phase voltage at each sampling time within a preset period before the relay protection device performs the protection action, thereby realizing the correction of the three-phase voltage.

[0084] Based on the corrected values ​​of current and voltage collected at each time point within a preset period before the relay protection device performs its protection action, the relay protection device is tested, and its qualification is determined based on the test results.

[0085] The process of testing relay protection devices based on current and voltage and determining whether the relay protection devices are qualified is a well-known technology and will not be described in detail here.

[0086] This completes the testing of the relay protection device.

[0087] Based on the same inventive concept as the above method, this application embodiment also provides an automatic testing system for relay protection devices, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-described automatic testing methods for relay protection devices.

[0088] The automatic testing system for relay protection devices includes a parameter configuration module, a test instantiation module, a test instrument control module, an automated test process control module, and an information display module.

[0089] The parameter configuration module is used to complete all basic parameter settings before testing. Based on the human-computer interface, the parameter configuration module enables basic parameter configuration using the CMS protocol. Configuration content includes offline full-site configuration description file parameters, report control block instance numbers, other report control block related parameters, automatic waveform file recall configuration, and remote control function configuration.

[0090] The test instantiation module generates test cases, which are simulated electrical parameters of faults issued to the relay protection device. It parses a template dictionary containing information such as logical nodes and dataset names, relying on a general test template and supporting fuzzy matching to achieve compatibility and decoupling with capability description files from different manufacturers. The module can add corresponding protection type test cases with a single click based on the fault type. After confirming the model of the relay protection device under test, it instantiates a general test model into test cases adapted to the current device under test.

[0091] The test instrument control module is responsible for sending increment files to the relay protection tester and receiving test results. It also sends test cases generated by the test instantiation module to the relay protection tester, driving the tester to execute the test cases on the relay protection device under test. The module collects test data generated in real time from the relay protection device's response to the test cases. This test data includes protection action duration and protection action accuracy data, providing data support for subsequent test evaluation.

[0092] The automated test process control module is the core scheduling module, automatically completing all test procedures based on the model of the relay protection device under test, the full-site configuration description file, and the test cases. The automated test process control module first establishes a communication link with the relay protection tester according to the project configuration, loading and executing all test case scripts within the project sequentially without manual intervention. During execution, it uniformly controls the tester to apply analog signals, issue remote control commands, read and write device settings, read event sequence records and fault waveform data, send interactive requests to the relay protection device under test, and simultaneously collect feedback data from the tester and response information from the relay protection device. After a single test case is completed, the actual response data of the relay protection device is summarized, and the actual response results are compared with the expected standard results to determine whether the current test case meets the protection action index requirements of the relay protection device.

[0093] The information display module is used to display information about the entire testing process, including communication connection status, file operation records, comprehensive operation information, key event information, and test result reports.

Claims

1. An automatic testing method for relay protection devices, characterized in that, The method includes the following steps: Collect the three-phase current and three-phase voltage of the tester output port and the relay protection device within a preset time period before the relay protection device performs its protection action; The current of any phase of the relay protection device is denoted as the target phase protection current. The current at the output port of the tester that is in the same phase as the target phase protection current is denoted as the target phase test current. Any acquisition time is denoted as the target acquisition time. A time window for the target acquisition time is constructed. The ratio of the root mean square of the amplitude of the target phase test current to the root mean square of the amplitude of the target phase protection current within the time window of the target acquisition time is denoted as the local energy deviation of the target phase protection current at the target acquisition time. Combining the first-order forward difference of the amplitudes of the target phase test current and the target phase protection current within the time window of the target acquisition time, the single-phase correction factor of the target phase protection current at the target acquisition time is calculated. Select the target current phase and the comparison current phase in the three-phase current. Based on the difference between the current at the output port of the tester and the current of the relay protection device in the same phase within the time window of the target acquisition time, calculate the current difference of the same phase at the target acquisition time. Combine the correlation of the current differences of the target current phase and the comparison current phase at each acquisition time within the time window of the target acquisition time, calculate the phase correction factor between the target current phase and the comparison current phase at the target acquisition time. Based on the value of the target current phase protection current at the target acquisition time, the single-phase correction factor of the target current phase protection current, and the phase-to-phase correction factor between the target current phase and the comparison current phase, the correction value of the target current phase current at the target acquisition time is calculated to complete the correction of the three-phase current. Following the method of correcting the three-phase current based on the output port of the tester and the three-phase current of the relay protection device, the correction of the three-phase voltage is achieved based on the output port of the tester and the three-phase voltage of the relay protection device. Based on the corrected current and voltage, the test of the relay protection device is completed. The calculation method for the single-phase correction factor of the target current phase protection current at the target acquisition time is as follows: based on the first-order forward difference value of the amplitude of the target current phase test current and the target current phase protection current within the time window of the target acquisition time, calculate the local fluctuation deviation of the target current phase protection current at the target acquisition time. The weighted sum of the local energy deviation and local fluctuation deviation of the target current phase protection current at the target acquisition time is denoted as the single-phase correction factor of the target current phase protection current at the target acquisition time, and the weighted sum of the local energy deviation and local fluctuation deviation is 1.

2. The automatic testing method for a relay protection device according to claim 1, characterized in that, The specific calculation method for the local fluctuation deviation of the target current phase protection current at the target acquisition time is as follows: Calculate the mean absolute value of the first forward difference of the amplitude of the target current phase test current within the time window of the target acquisition time, and the mean absolute value of the first forward difference of the amplitude of the target current phase protection current within the time window of the target acquisition time. Record these as the first mean and the second mean within the time window of the target acquisition time. Record the ratio of the first mean to the second mean within the time window of the target acquisition time as the local fluctuation deviation of the target current phase protection current at the target acquisition time.

3. The automatic testing method for a relay protection device according to claim 1, characterized in that, The current difference of the same phase at the target acquisition time is: the difference between the current at the output port of the tester at the target acquisition time and the current of the same phase of the relay protection device.

4. The automatic testing method for a relay protection device according to claim 1, characterized in that, The method for calculating the interphase correction factor between the target current phase and the comparison current phase at the target acquisition time is as follows: Establish the current difference sequence of each current phase at the target acquisition time, and denote the absolute value of the Pearson correlation coefficient between the current difference sequences of the target current phase and the comparison current phase at the target acquisition time as the error synchronization index between the target current phase and the comparison current phase at the target acquisition time. The difference between the absolute values ​​of the current differences between the comparison current phase and the target current phase at the target acquisition time and the maximum value of the number 0 are selected and denoted as the interphase coupling propagation error between the target current phase and the comparison current phase at the target acquisition time. The product of the interphase coupling conduction error and the error synchronization index between the target current phase and the comparison current phase at the target acquisition time is denoted as the interphase correction factor between the target current phase and the comparison current phase at the target acquisition time.

5. The automatic testing method for a relay protection device according to claim 1, characterized in that, The method for calculating the correction value of the target current phase at the target acquisition time is as follows: When the protection current of the target current phase is greater than 0 at the target acquisition time, the data polarity coefficient of the target current phase at the target acquisition time is assigned to 1; when the protection current of the target current phase is less than 0 at the target acquisition time, the data polarity coefficient of the target current phase at the target acquisition time is assigned to -1. When the target current phase protection current is equal to 0 at the target acquisition time, the data polarity coefficient of the target current phase at the target acquisition time is set to 0. By combining the phase-to-phase correction factors of the target current phase and the comparison current phase at the target acquisition time, the phase-to-phase correction value of the target current phase at the target acquisition time is calculated. The sum of the product of the single-phase correction factor of the target current phase protection current at the target acquisition time and the target current phase protection current and the phase-to-phase correction value is used as the correction value of the target current phase current at the target acquisition time.

6. The automatic testing method for a relay protection device according to claim 5, characterized in that, The phase-to-phase correction value of the target current phase at the target acquisition time is the product of the mean of the phase-to-phase correction factors of the target current phase and the two comparison current phases at the target acquisition time and the data polarity coefficient of the target current phase at the target acquisition time.

7. An automatic testing system for relay protection devices, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as claimed in any one of claims 1-6.

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