A method and system for verifying the accuracy of fault location of traveling wave switches in distribution networks

Abstract

The present invention discloses a method and system for verifying the fault location accuracy of a distribution network traveling wave switch, and relates to the technical field of distribution network. The method for verifying the fault location accuracy includes: simulating an actual cable line and checking the line length, combining the transformer isolation line voltage to obtain the power required by the distribution network traveling wave switch; controlling the resistor action to simulate the line fault occurrence time, and combining the capacitor charging and discharging action to simulate the load of different users of the line, and judging the line energized or fault occurrence and power outage through the line energized indication signal; configuring the traveling wave switch based on the power required by the distribution network traveling wave switch, and verifying the fault location accuracy of the distribution network traveling wave switch in combination with the line length, the line fault occurrence time and the fault simulation result. The present invention reasonably arranges the traveling wave monitoring points according to the line length to ensure that the traveling wave signal can be quickly monitored when a fault occurs, and collects the traveling wave signal when the fault occurs and the time difference of the signal propagating to each monitoring point through the configured traveling wave switch.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution network, and in particular to a method and system for verifying the fault location accuracy of a traveling wave switch in a distribution network. Background Art

[0002] The distribution network traveling wave switch is a switching device specially used to detect and capture electromagnetic traveling wave signals in power systems. It is mainly used in fault detection and location systems, especially when a distribution network line fails, it can quickly respond to the fault and trigger the corresponding traveling wave signal acquisition. The configuration and application of the traveling wave switch helps to improve the accuracy and efficiency of fault location.

[0003] When a fault occurs in the power system, the traveling wave switch can quickly capture the traveling wave signal caused by the fault, locate the fault point by analyzing the propagation time difference of these signals and using the traveling wave fault location model. However, since the location of the fault point will be affected by factors such as equipment errors and environmental factors, positioning deviations may occur. If the fault location accuracy of the distribution network traveling wave switch cannot be verified, it will affect the accuracy of the fault location and thus fail to provide reliable fault location information.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] In view of the problems in the related art, the present invention proposes a method and system for verifying the fault location accuracy of a traveling wave switch in a distribution network to overcome the above-mentioned technical problems existing in the existing related art.

[0006] To this end, the specific technical solution adopted by the present invention is as follows:

[0007] According to one aspect of the present invention, a method for verifying the fault location accuracy of a traveling wave switch in a distribution network is provided, and the method for verifying the fault location accuracy comprises:

[0008] S1, simulate the actual cable line and check the line length, and combine the transformer isolation line voltage to obtain the power required by the distribution network traveling wave switch;

[0009] S2, control the resistor action to simulate the moment of line fault, and combine the capacitor charging and discharging action to simulate the load of different users on the line, and use the line power indication signal to determine whether the line is powered or a fault occurs and power outage occurs;

[0010] S3. Configure the traveling wave switch based on the power supply required by the distribution network traveling wave switch, and verify the fault location accuracy of the distribution network traveling wave switch in combination with the line length, the time when the line fault occurs and the fault simulation results.

[0011] Preferably, simulating an actual cable line and checking the line length, and obtaining the power required for the traveling wave switch of the distribution network in combination with the transformer isolation line voltage includes:

[0012] S11. Building a fault simulation environment based on a preset voltage level, and simulating an actual cable line through a signal line in the fault simulation environment;

[0013] S12, using time domain reflection technology to send a pulse signal to the signal line and detect the reflection time point of the pulse signal, and combining the reflection time point and wave speed of the pulse signal to check the line length;

[0014] S13, isolating the preset voltage level through a transformer to simulate the line voltage, and obtaining the power required by the traveling wave switch of the distribution network.

[0015] Preferably, using time domain reflection technology to send a pulse signal to the signal line and detect the reflection time point of the pulse signal, combining the reflection time point and wave speed of the pulse signal to check the line length includes:

[0016] S121, setting the time domain reflectometer to a pulse type matching the configuration of the signal line, connecting the signal line to the time domain reflectometer and sending a pulse signal to the signal line;

[0017] S122, collecting and recording the reflected signal and the return time point when the pulse signal propagates along the signal line to the terminal, and calculating the round-trip time of the pulse signal in combination with the transmission time point and the reflection time point;

[0018] S123. Calculate the propagation speed of the pulse signal in the signal line according to the physical characteristics of the cable, and predict the line length in combination with the round-trip time of the pulse signal.

[0019] Preferably, controlling the resistor action to simulate the line fault occurrence time, and combining the capacitor charging and discharging action to simulate the line loads of different users, and judging the line power-on or fault occurrence and power outage through the line power-on indication signal include:

[0020] S21, connecting a resistor to a signal line and controlling the resistor to trigger a fault through a relay, and recording the exact moment of the resistor action when the fault is triggered as reference time data;

[0021] S22, after the fault is triggered, using a voltage monitoring device to collect a time series signal of the capacitor voltage changing with time and use it as charging and discharging time data;

[0022] S23, synchronizing the reference time data and the charge and discharge time data according to the timestamps to ensure that the time series data remain on the same time scale;

[0023] S24, using time series analysis technology to perform time series analysis on the reference time data and the charge and discharge time data, and evaluate the time relationship between the fault simulation and the capacitor charge and discharge action;

[0024] S25. The fault simulation result is determined based on the time relationship. If the time relationship meets the preset conditions, the fault simulation result is determined to be a success state. Otherwise, the capacitor charging and discharging is determined to be a hysteresis behavior, and the hysteresis action is quantified using the hysteresis analysis technology.

[0025] Preferably, using time series analysis technology to perform time series analysis on the reference time data and the charge and discharge time data, and evaluating the time relationship between the fault simulation and the capacitor charge and discharge action includes:

[0026] S241, using a structural mutation test to identify a first optimal segmentation point in the reference time data, wherein the first optimal segmentation point represents an important time node when a resistor action triggers a fault;

[0027] S242, repeatedly performing a structural mutation test on the time series data between the starting point of the charge and discharge time data and the first optimal segmentation point to obtain a second optimal segmentation point for the charge and discharge time data;

[0028] S243, marking the time series data segment between the first optimal segmentation point and the second optimal segmentation point as a constant data segment, and performing a stationarity test on the constant data segment;

[0029] S244, adjusting the starting point of the first best segmentation point and the end point of the second best segmentation point based on the stationarity test result of the constant data segment to obtain an updated constant data segment;

[0030] S245. Repeat steps S243-S244 until the best constant data segment is found, and use the best constant data segment to describe the time relationship between the fault simulation and the capacitor charging and discharging action.

[0031] Preferably, performing a stationarity test on a constant data segment comprises:

[0032] S2431. If the constant data segment is in a stable state, it indicates that the fault simulation and the capacitor charging and discharging action are in a stable state in terms of timing, and the constant data segment is used as the final output;

[0033] S2432: If the constant data segment is in an unstable state, the constant data segment is divided into a front data segment and a rear data segment, which respectively represent the fault response stages before and after the capacitor is charged and discharged.

[0034] Preferably, configuring the traveling wave switch based on the power supply required by the traveling wave switch of the distribution network, and verifying the fault location accuracy of the traveling wave switch of the distribution network in combination with the line length, the time when the line fault occurs and the fault simulation results include:

[0035] S31, connecting the behavior switch to a preset position based on the power required by the distribution network traveling wave switch, and arranging the traveling wave monitoring points based on the line length;

[0036] S32, using the configured traveling wave switch to collect the traveling wave signal generated when the fault is triggered in real time, and calculate the time difference of the traveling wave signal propagating to each traveling wave monitoring point;

[0037] S33, fusing several time differences and using the fault location model to calculate the fault point location, repeatedly performing traveling wave acquisition at the fault point location, and eliminating abnormal points in the fault location model;

[0038] S34. Output the fault location through the fault location model and compare it with the actual fault location collected by the fault simulator, and verify the fault location accuracy of the distribution network traveling wave switch based on the comparison result.

[0039] Preferably, the fault location model is used to output the fault point location and compare it with the actual fault point collected by the fault simulator, and the fault location accuracy of the distribution network traveling wave switch is verified based on the comparison result, including:

[0040] S341, using a fault simulator to collect the actual fault point when the fault is triggered and compare it with the fault point position output by the fault location model to generate a fault location error;

[0041] S342, formulating a confidence interval of a fault location error of a distribution network traveling wave switch, and evaluating a credible range of fault location accuracy of the distribution network traveling wave switch;

[0042] S343. Optimize the fault location model parameters and adjust the layout of traveling wave monitoring points based on the credible range of fault location accuracy.

[0043] Preferably, the expression of the fault location model is: ;

[0044] In the formula, Indicates the location of the fault point; V wave represents the propagation speed of traveling waves; t i Indicates that the traveling wave signal propagates to the i The time difference of the traveling wave monitoring points; t j Indicates that the traveling wave signal propagates to the j The time difference between the traveling wave monitoring points.

[0045] According to another aspect of the present invention, a distribution network traveling wave switch fault location accuracy verification system is also provided, the fault location accuracy verification system comprising a line length verification module, a fault simulation judgment module and a fault location verification module;

[0046] The line length verification module is used to simulate the actual cable line and verify the line length, and obtain the power required by the distribution network traveling wave switch in combination with the transformer isolation line voltage;

[0047] The fault simulation judgment module is used to control the resistor action to identify the time when the line fault occurs, and obtain the line power indication signal in combination with the capacitor charging and discharging action to judge the fault simulation result;

[0048] The fault location verification module is used to configure the traveling wave switch based on the power supply required by the distribution network traveling wave switch, and verify the fault location accuracy of the distribution network traveling wave switch in combination with the line length, the time when the line fault occurs and the fault simulation results.

[0049] The beneficial effects of the present invention are:

[0050] 1. The present invention can accurately capture the moment of fault occurrence and analyze the fault trigger response by triggering faults, synchronizing time data and timing analysis technology, laying the foundation for verifying the fault location accuracy. The time series data of capacitor charging and discharging combined with the resistor action trigger time can effectively verify whether the fault simulation results meet expectations. At the same time, the data segment is automatically adjusted through structural mutation and stability inspection to improve the stability and accuracy of the analysis results. Then, the fault response stage is refined through precise time series analysis, and the distribution network traveling wave switch fault location model is further optimized.

[0051] 2. The present invention reasonably arranges traveling wave monitoring points according to the line length to ensure that the traveling wave signal can be quickly monitored when a fault occurs, and collects the traveling wave signal when the fault occurs and the time difference of the signal propagating to each monitoring point through the configured traveling wave switch, thereby ensuring a rapid response to the fault location. Using these precise time differences to input into the fault location model helps to improve the accuracy and stability of fault point location. At the same time, the fault point location output by the fault location model is compared with the actual fault point location collected by the fault simulator, thereby effectively verifying the accuracy of the fault location model and objectively verifying the fault location accuracy of the traveling wave switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 is a flow chart of a method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to an embodiment of the present invention;

[0054] Figure 2is a principle block diagram of a distribution network traveling wave switch fault location accuracy verification system according to an embodiment of the present invention;

[0055] Figure 3 is a circuit model diagram of a distribution network traveling wave switch fault location accuracy verification system according to an embodiment of the present invention;

[0056] Figure 4 is a power supply principle diagram of a distribution network traveling wave switch fault location accuracy verification system according to an embodiment of the present invention;

[0057] Figure 5 The present invention is a schematic diagram of a simulated fault of a distribution network traveling wave switch fault location accuracy verification system according to an embodiment of the present invention.

[0058] In the figure:

[0059] 1. Line length verification module; 2. Fault simulation judgment module; 3. Fault location verification module. DETAILED DESCRIPTION

[0060] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments. They can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and advantages of the present invention.

[0061] According to an embodiment of the present invention, a method and system for verifying the fault location accuracy of a traveling wave switch in a distribution network are provided.

[0062] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1 As shown, according to a method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to an embodiment of the present invention, the method for verifying the fault location accuracy includes:

[0063] S1. Simulate the actual cable line and check the line length, and combine the transformer isolation line voltage to obtain the power required by the distribution network traveling wave switch.

[0064] Among them, simulating the actual cable line and checking the line length, combining the transformer isolation line voltage to obtain the power supply required for the distribution network traveling wave switch includes:

[0065] S11. Building a fault simulation environment based on a preset voltage level, and simulating an actual cable line through a signal line in the fault simulation environment;

[0066] S12. Use time domain reflection technology to send a pulse signal to the signal line and detect the reflection time point of the pulse signal, and combine the reflection time point and wave speed of the pulse signal to check the line length.

[0067] Among them, using time domain reflection technology to send a pulse signal to the signal line and detect the reflection time point of the pulse signal, combining the reflection time point and wave speed of the pulse signal to check the line length includes:

[0068] S121, setting the time domain reflectometer to a pulse type matching the configuration of the signal line, connecting the signal line to the time domain reflectometer and sending a pulse signal to the signal line;

[0069] S122. Collect and record the reflected signal and return time point when the pulse signal propagates along the signal line to the terminal, and calculate the round-trip time of the pulse signal in combination with the transmission time point and the reflection time point.

[0070] It should be noted that the reflected signal and return time point when the pulse signal propagates along the signal line to the terminal are collected and recorded, and the round-trip time of the pulse signal is calculated in combination with the transmission time point and the reflection time point.

[0071] At the starting point of the signal line, a pulse signal is sent to the line and the transmission time point T1 is recorded; the pulse signal propagates in the signal line, and when it encounters a terminal or a discontinuity point in the line (such as impedance mismatch), a reflected signal is generated, and the reflected signal returns along the line and is finally received by the acquisition device; when the reflected signal returns to the starting point, the reflection time point T2 is recorded, which indicates the moment when the reflected signal returns to the starting position; the round-trip time of the pulse signal (i.e., the time from transmission to the return of the reflected signal) is calculated by the difference between the transmission time point and the reflection time point; if the signal propagation speed v is known, and the distance the signal traveled is calculated based on the round-trip time.

[0072] S123. Calculate the propagation speed of the pulse signal in the signal line according to the physical characteristics of the cable, and predict the line length in combination with the round-trip time of the pulse signal.

[0073] S13, isolating the preset voltage level through a transformer to simulate the line voltage, and obtaining the power required by the traveling wave switch of the distribution network.

[0074] S2. Control the resistor action to simulate the moment when a line fault occurs, and combine the capacitor charging and discharging action to simulate the loads of different users on the line. Use the line power indication signal to determine whether the line is powered or a fault occurs and cause a power outage.

[0075] Among them, controlling the action of the resistor to simulate the moment of line fault occurrence, and combining the charging and discharging action of the capacitor to simulate the load of different users on the line, judging the line power-on indication signal to determine whether the line is powered or a fault occurs and power outages include:

[0076] S21, connecting a resistor to a signal line and controlling the resistor to actuate through a relay to trigger a fault, and recording the exact moment of the resistor actuation as reference time data when the fault is triggered.

[0077] It should be noted that connecting a resistor to a signal line means connecting a controllable resistor to the signal line, which is usually controlled to be turned on or off by a relay. This resistor is used for fault simulation in order to test and analyze the fault response behavior of the system.

[0078] Triggering faults by controlling the action of resistors through relays: The role of relays is to control the access of resistors. When the relay is activated (i.e. the switch is turned on), the resistor will be connected to the line, which will cause electrical faults in the line, such as short circuits, overloads, etc. This fault is deliberately triggered to simulate real fault conditions for analysis and fault location testing.

[0079] Record the exact moment of resistor action as reference time data: When the resistor is connected to the line and triggers a fault, record the exact moment when the resistor is connected or disconnected. This time point is called the reference time and is the reference point for all subsequent time analysis. In fault location, the reference time data is the key basis for determining the time when other events (such as capacitor charging and discharging, fault response, etc.) occur.

[0080] S22. After the fault is triggered, a voltage monitoring device is used to collect a time series signal of the capacitor voltage changing with time and use it as charging and discharging time data.

[0081] It should be noted that when the resistor is connected and triggers a line fault, the capacitor in the system will undergo a charging and discharging reaction, because the capacitor is usually an energy storage element in the circuit and can alleviate sudden changes in voltage and current in the circuit.

[0082] The voltage changes of the capacitor are monitored and recorded in real time through voltage monitoring equipment (such as an oscilloscope or voltage sensor). During the charging and discharging process of the capacitor, its voltage will show a specific change pattern over time. This change process is recorded as a time series data to analyze the performance of the capacitor charging and discharging behavior during the fault period.

[0083] S23, synchronizing the reference time data and the charge and discharge time data according to the timestamps to ensure that the time series data remain on the same time scale;

[0084] S24. Use time series analysis technology to perform time series analysis on the reference time data and the charge and discharge time data to evaluate the time relationship between the fault simulation and the capacitor charge and discharge action.

[0085] Among them, the time series analysis technology is used to perform time series analysis on the reference time data and the charging and discharging time data, and the time relationship between the fault simulation and the capacitor charging and discharging action is evaluated, including:

[0086] S241. Using a structural mutation test to identify a first optimal segmentation point in the reference time data, wherein the first optimal segmentation point represents an important time node when a resistor action triggers a fault.

[0087] It should be noted that structural mutation test is a statistical method used to identify sudden changes in trends, fluctuations or distributions in time series data. In the application of power system fault location, structural mutation test helps to find significant change points in the data, called mutation points, which are usually related to sudden changes in system behavior.

[0088] The first best segmentation point is identified in the benchmark time data by using the structural mutation test, and the first best segmentation point represents the important time nodes when the resistor action triggers the fault, including:

[0089] The benchmark time data is the time series data recorded when the resistor action triggers the fault, which reflects the critical moment when the fault occurs. An obvious time node is found in these data through the structural mutation test, indicating a significant change in the data; the first best split point refers to the most significant time node found by the structural mutation test. This node represents the starting point of the fault, that is, the exact moment when the resistor action triggers the fault.

[0090] Structural mutation tests usually detect such mutation points through statistical methods, such as cumulative sum test (CUSUM), Chow test, Pettitt test, etc. In time series, these mutation points can be marked as "split points" to divide different stages of data.

[0091] S242, repeatedly performing a structural mutation test on the time series data between the starting point of the charge and discharge time data and the first optimal segmentation point to obtain a second optimal segmentation point for the charge and discharge time data;

[0092] S243, marking the time series data segment between the first optimal segmentation point and the second optimal segmentation point as a constant data segment, and performing a stationarity test on the constant data segment.

[0093] Among them, the stationarity test for the constant data segment includes:

[0094] S2431. If the constant data segment is in a stable state, it indicates that the fault simulation and the capacitor charging and discharging action are in a stable state in terms of timing, and the constant data segment is used as the final output;

[0095] S2432: If the constant data segment is in an unstable state, the constant data segment is divided into a front data segment and a rear data segment, which respectively represent the fault response stages before and after the capacitor is charged and discharged.

[0096] S244, adjusting the starting point of the first best segmentation point and the end point of the second best segmentation point based on the stationarity test result of the constant data segment to obtain an updated constant data segment;

[0097] S245. Repeat steps S243-S244 until the best constant data segment is found, and use the best constant data segment to describe the time relationship between the fault simulation and the capacitor charging and discharging action.

[0098] S25. The fault simulation result is determined based on the time relationship. If the time relationship meets the preset conditions, the fault simulation result is determined to be a success state. Otherwise, the capacitor charging and discharging is determined to be a hysteresis behavior, and the hysteresis action is quantified using the hysteresis analysis technology.

[0099] It should be noted that determining the capacitor charging and discharging as a hysteresis behavior and quantifying the hysteresis action using hysteresis analysis technology includes:

[0100] When the resistor is connected to the line to trigger the fault, the recorded reference time represents the exact moment when the fault occurs. At this time, the charging and discharging process of the capacitor should respond quickly to the fault.

[0101] If the analysis shows that the charge and discharge start time of the capacitor is later than the reference time, that is, the voltage change of the capacitor is delayed, it indicates that there is a lag in the response of the capacitor. At this time, it is necessary to determine whether this lag is within the normal range or is an abnormality caused by other reasons (such as equipment performance problems, system delays, etc.).

[0102] Hysteresis analysis technology is used to quantitatively evaluate the degree of hysteresis of capacitor charging and discharging behavior relative to the time of fault occurrence. Hysteresis analysis technology quantifies hysteresis behavior through various methods. For example:

[0103] Time series regression analysis: Use a time series regression model to analyze the correlation between charge and discharge time data and fault trigger time, and quantify the degree of capacitor response lag.

[0104] Hysteresis response model: Use specific hysteresis response models to describe the dynamic behavior of hysteresis in the system and predict the scope and impact of hysteresis.

[0105] S3. Configure the traveling wave switch based on the power supply required by the distribution network traveling wave switch, and verify the fault location accuracy of the distribution network traveling wave switch in combination with the line length, the time when the line fault occurs and the fault simulation results.

[0106] Among them, the traveling wave switch is configured based on the power supply required by the distribution network traveling wave switch, and the fault location accuracy of the distribution network traveling wave switch is verified by combining the line length, the time when the line fault occurs and the fault simulation results, including:

[0107] S31, connecting the behavior switch to a preset position based on the power required by the distribution network traveling wave switch, and arranging the traveling wave monitoring points based on the line length;

[0108] S32, using the configured traveling wave switch to collect the traveling wave signal generated when the fault is triggered in real time, and calculate the time difference of the traveling wave signal propagating to each traveling wave monitoring point;

[0109] S33, integrating several time differences and using the fault location model to calculate the fault point location, repeatedly performing traveling wave acquisition at the fault point location, and eliminating abnormal points in the fault location model.

[0110] Among them, the expression of the fault location model is: ;

[0111] In the formula, Indicates the location of the fault point; V wave represents the propagation speed of traveling waves; t i Indicates that the traveling wave signal propagates to the i The time difference of the traveling wave monitoring points; t j Indicates that the traveling wave signal propagates to the j The time difference between the traveling wave monitoring points.

[0112] S34. Output the fault location through the fault location model and compare it with the actual fault location collected by the fault simulator, and verify the fault location accuracy of the distribution network traveling wave switch based on the comparison result.

[0113] Among them, the fault location model outputs the fault point location and compares it with the actual fault point collected by the fault simulator. The fault location accuracy of the distribution network traveling wave switch is verified based on the comparison results, including:

[0114] S341, using a fault simulator to collect the actual fault point when the fault is triggered and compare it with the fault point position output by the fault location model to generate a fault location error;

[0115] S342. Develop a confidence interval for the fault location error of the distribution network traveling wave switch, and evaluate the credible range of the fault location accuracy of the distribution network traveling wave switch.

[0116] It should be noted that the confidence interval of the fault location error of the distribution network traveling wave switch is formulated, and the credible range of the fault location accuracy of the distribution network traveling wave switch is evaluated, including:

[0117] Fault location error: Fault location error refers to the difference between the fault point location calculated by the fault location model and the actual fault point location. This error comes from multiple factors, such as time synchronization error, reflection of traveling wave signals, inaccurate model parameters, etc.

[0118] Confidence interval formulation: Confidence interval is a statistical tool used to express the range of fault location error under a certain probability. The distribution of location error is statistically analyzed by analyzing a large number of fault location results and their corresponding actual fault points. Assuming that the error follows a certain distribution (such as normal distribution), the error interval is calculated at a certain confidence level (such as 95%), that is, the error value of fault location will fall within this interval with a certain probability.

[0119] S343. Optimize the fault location model parameters and adjust the layout of traveling wave monitoring points based on the credible range of fault location accuracy.

[0120] like Figure 2 As shown, according to another embodiment of the present invention, a distribution network traveling wave switch fault location accuracy verification system is also provided, the fault location accuracy verification system includes a line length verification module 1, a fault simulation judgment module 2 and a fault location verification module 3;

[0121] The line length checking module 1 is used to simulate the actual cable line and check the line length, and obtain the power required by the traveling wave switch of the distribution network in combination with the transformer isolation line voltage.

[0122] In specific applications, a 50Ω coaxial cable (signal cable) is used to simulate the actual 10kV insulated cable line with the same wave impedance, and a 750V voltage is used to simulate the 10kV line voltage through transformer isolation to provide the power required for the traveling wave test.

[0123] The fault simulation judgment module 2 is used to control the resistor action to identify the time when the line fault occurs, and obtain the line power indication signal in combination with the capacitor charging and discharging action to judge the fault simulation result.

[0124] In specific applications, the contactor is used to close and disconnect the control resistor to simulate the actual line fault occurrence moment, and the CBB capacitor parallel indicator light is used to simulate the line diagram parameters and provide the line power indication signal.

[0125] The fault location verification module 3 is used to configure the traveling wave switch based on the power supply required by the distribution network traveling wave switch, and verify the fault location accuracy of the distribution network traveling wave switch in combination with the line length, the time when the line fault occurs and the fault simulation results.

[0126] In specific applications, the distribution network traveling wave switch is connected to the corresponding switch position to simulate the corresponding fault, which can verify the fault location accuracy of the traveling wave system. By using a three-phase plug as an intermediate adapter and connecting it at any position of the line, the line fault can be simulated and the location accuracy of different fault points can be verified.

[0127] The present invention is further described in detail below in conjunction with a specific traveling wave system dynamic model test scheme:

[0128] 1. Test requirements:

[0129] 1. Use 750V voltage level to build a traveling wave test simulation environment;

[0130] 2. Use 50Ω coaxial cable to simulate the actual 10kV insulated cable line;

[0131] 3. Mainly simulate the attenuation and delay of the traveling wave signal transmission process, the total delay should be greater than 1uS;

[0132] 4. The switch grounding should be independent to avoid interference on the construction site (the distance between the grounding points should be greater than 20 meters);

[0133] 5. The power supply should be isolated from the main power supply to reduce grid interference;

[0134] 6. The analog fault circuit should be isolated from the main circuit power supply to reduce its own interference;

[0135] 7. Simulate the circuit of three or four devices;

[0136] 8. Simulate different line lengths of main line and branch line;

[0137] 9. Simulate fault points at different locations such as the beginning, middle, branch and end of the line;

[0138] 10. Set the ground fault with different resistance fault resistors;

[0139] 11.Simulate series resistance gap discharge fault.

[0140] 2. Environmental construction plan:

[0141] The environmental construction plan includes establishing a line model, implementing power supply and simulating faults. The line model diagram is as follows: Figure 3 As shown; the power supply schematic diagram is as follows Figure 4 As shown; the simulation fault schematic diagram is as follows Figure 5 shown.

[0142] 3. Test plan:

[0143] 1. Simulate power supply and verify line length;

[0144] 2. Simulate faults at different points to verify the accuracy of the system’s positioning judgment;

[0145] 3. Simulate different ground resistance faults to verify the changes in traveling wave signals;

[0146] 4. Simulate arc discharge fault to check the accuracy of system judgment.

[0147] 4. Dynamic mold test method:

[0148] 1. According to the 750V power supply plan, check the line wiring to ensure that the environment operates normally;

[0149] 2. Connect the device to the system and the device and system are running normally;

[0150] 3. Set the fault point, select the required resistor, and connect to the analog line;

[0151] 4. Power the line, close the air switch, adjust the voltage regulator to the appropriate position, press the power button, the power indicator light up, and the line parameter indicator light up;

[0152] 5. After checking that the operation is normal, turn on the battery switch and press the fault button. The fault indicator light will light up and the simulated fault is successful.

[0153] 6. Wait for data to be sent and check the system positioning and judgment situation;

[0154] 7. Record the data and continue with Test 5;

[0155] 8. If you need to change the grounding point or grounding resistance, please press the power off button to ensure that the line is powered off, and then continue with the third test;

[0156] 9. After the test is completed, press the power off button to disconnect the air switch and battery switch.

[0157] In summary, with the help of the above-mentioned technical scheme of the present invention, the present invention can accurately capture the moment of fault occurrence and analyze the fault trigger response by triggering faults, synchronizing time data and timing analysis technology, laying the foundation for verifying the accuracy of fault location, and using the time series data of capacitor charging and discharging combined with the resistor action trigger time to effectively verify whether the fault simulation results meet expectations, and automatically adjust the data segment through structural mutation and stability test to improve the stability and accuracy of the analysis results, and then refine the fault response stage through accurate time series analysis, and further optimize the distribution network traveling wave switch fault location model; the present invention reasonably arranges the traveling wave monitoring points according to the line length to ensure that the traveling wave signal can be quickly monitored when a fault occurs, and collects the traveling wave signal when the fault occurs and the time difference of the signal propagating to each monitoring point through the configured traveling wave switch, ensuring a rapid response to the fault location, and using these accurate time differences to input the fault location model helps to improve the accuracy and stability of the fault point location, and at the same time, the fault point location output by the fault location model is compared with the actual fault point location collected by the fault simulator, thereby effectively verifying the accuracy of the fault location model and objectively verifying the fault location accuracy of the traveling wave switch.

[0158] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network, characterized in that: The fault location accuracy verification method includes: S1, simulate the actual cable line and check the line length, and combine the transformer isolation line voltage to obtain the power required by the distribution network traveling wave switch; S2, control the resistor action to simulate the moment of line fault, and combine the capacitor charging and discharging action to simulate the load of different users on the line, and use the line power indication signal to determine whether the line is powered or a fault occurs and power outage occurs; S3. Configure the traveling wave switch based on the power supply required by the traveling wave switch of the distribution network, and verify the fault location accuracy of the traveling wave switch of the distribution network in combination with the line length, the time when the line fault occurs and the fault simulation results; The control resistor action simulates the moment of line fault occurrence, and combines the capacitor charging and discharging action to simulate the load of different users on the line, and uses the line power indication signal to determine whether the line is powered or a fault occurs and power outages include: S21, connecting a resistor to a signal line and controlling the resistor to trigger a fault through a relay, and recording the exact moment of the resistor action when the fault is triggered as reference time data; S22, after the fault is triggered, using a voltage monitoring device to collect a time series signal of the capacitor voltage changing with time and use it as charging and discharging time data; S23, synchronizing the reference time data and the charge and discharge time data according to the timestamps to ensure that the time series data remain on the same time scale; S24, using time series analysis technology to perform time series analysis on the reference time data and the charge and discharge time data, and evaluate the time relationship between the fault simulation and the capacitor charge and discharge action; S25. The fault simulation result is determined based on the time relationship. If the time relationship meets the preset conditions, the fault simulation result is determined to be a success state. Otherwise, the capacitor charging and discharging is determined to be a hysteresis behavior, and the hysteresis action is quantified using the hysteresis analysis technology.

2. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to claim 1, characterized in that: The simulation of the actual cable line and checking the line length, and obtaining the power required by the traveling wave switch of the distribution network in combination with the transformer isolation line voltage, comprises: S11. Building a fault simulation environment based on a preset voltage level, and simulating an actual cable line through a signal line in the fault simulation environment; S12, using time domain reflection technology to send a pulse signal to the signal line and detect the reflection time point of the pulse signal, and combining the reflection time point and wave speed of the pulse signal to check the line length; S13, isolating the preset voltage level through a transformer to simulate the line voltage, and obtaining the power required by the traveling wave switch of the distribution network.

3. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to claim 2, characterized in that: The method of using the time domain reflection technology to send a pulse signal to the signal line and detect the reflection time point of the pulse signal, and combining the reflection time point and wave speed of the pulse signal to check the line length includes: S121, setting the time domain reflectometer to a pulse type matching the configuration of the signal line, connecting the signal line to the time domain reflectometer and sending a pulse signal to the signal line; S122, collecting and recording the reflected signal and the return time point when the pulse signal propagates along the signal line to the terminal, and calculating the round-trip time of the pulse signal in combination with the transmission time point and the reflection time point; S123. Calculate the propagation speed of the pulse signal in the signal line according to the physical characteristics of the cable, and predict the line length in combination with the round-trip time of the pulse signal.

4. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to claim 3, characterized in that: The time series analysis of the reference time data and the charge and discharge time data by using the time series analysis technology to evaluate the time relationship between the fault simulation and the capacitor charge and discharge action includes: S241, using a structural mutation test to identify a first optimal segmentation point in the reference time data, wherein the first optimal segmentation point represents an important time node when a resistor action triggers a fault; S242, repeatedly performing a structural mutation test on the time series data between the starting point of the charge and discharge time data and the first optimal segmentation point to obtain a second optimal segmentation point for the charge and discharge time data; S243, marking the time series data segment between the first optimal segmentation point and the second optimal segmentation point as a constant data segment, and performing a stationarity test on the constant data segment; S244, adjusting the starting point of the first best segmentation point and the end point of the second best segmentation point based on the stationarity test result of the constant data segment to obtain an updated constant data segment; S245. Repeat steps S243-S244 until the best constant data segment is found, and use the best constant data segment to describe the time relationship between the fault simulation and the capacitor charging and discharging action.

5. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to claim 4, characterized in that: The stationarity test of the constant data segment comprises: S2431. If the constant data segment is in a stable state, it indicates that the fault simulation and the capacitor charging and discharging action are in a stable state in terms of timing, and the constant data segment is used as the final output; S2432: If the constant data segment is in an unstable state, the constant data segment is divided into a front data segment and a rear data segment, which respectively represent the fault response stages before and after the capacitor is charged and discharged.

6. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to claim 5, characterized in that: The configuration of the traveling wave switch based on the power supply required by the traveling wave switch of the distribution network and verification of the fault location accuracy of the traveling wave switch of the distribution network in combination with the line length, the time of occurrence of the line fault and the fault simulation result include: S31, connecting the behavior switch to a preset position based on the power required by the distribution network traveling wave switch, and arranging the traveling wave monitoring points based on the line length; S32, using the configured traveling wave switch to collect the traveling wave signal generated when the fault is triggered in real time, and calculate the time difference of the traveling wave signal propagating to each traveling wave monitoring point; S33, fusing several time differences and using the fault location model to calculate the fault point location, repeatedly performing traveling wave acquisition at the fault point location, and eliminating abnormal points in the fault location model; S34. Output the fault location through the fault location model and compare it with the actual fault location collected by the fault simulator, and verify the fault location accuracy of the distribution network traveling wave switch based on the comparison result.

7. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to claim 6, characterized in that: Outputting the fault location through the fault location model and comparing it with the actual fault location acquired by the fault simulator, and verifying the fault location accuracy of the distribution network traveling wave switch based on the comparison result include: S341, using a fault simulator to collect the actual fault point when the fault is triggered and compare it with the fault point position output by the fault location model to generate a fault location error; S342, formulating a confidence interval of a fault location error of a distribution network traveling wave switch, and evaluating a credible range of fault location accuracy of the distribution network traveling wave switch; S343. Optimize the fault location model parameters and adjust the layout of traveling wave monitoring points based on the credible range of fault location accuracy.

8. A method for verifying the fault location accuracy of a traveling wave switch in a distribution network according to claim 7, characterized in that: The expression of the fault location model is: ; In the formula, Indicates the location of the fault point; V wave represents the propagation speed of traveling waves; t i Indicates that the traveling wave signal propagates to the i The time difference of the traveling wave monitoring points; t j Indicates that the traveling wave signal propagates to the j The time difference between the traveling wave monitoring points.

9. A distribution network traveling wave switch fault location accuracy verification system, used to implement the distribution network traveling wave switch fault location accuracy verification method according to any one of claims 1 to 8, characterized in that: The fault location accuracy verification system includes a line length verification module, a fault simulation judgment module and a fault location verification module; The line length checking module is used to simulate the actual cable line and check the line length, and obtain the power required by the traveling wave switch of the distribution network in combination with the transformer isolation line voltage; The fault simulation judgment module is used to control the resistor action to identify the time when the line fault occurs, and obtain the line power indication signal in combination with the capacitor charging and discharging action to judge the fault simulation result; The fault location verification module is used to configure the traveling wave switch based on the power supply required by the distribution network traveling wave switch, and verify the fault location accuracy of the distribution network traveling wave switch in combination with the line length, the time when the line fault occurs and the fault simulation result.

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