Mobile substation cable fault positioning method

Abstract

The invention discloses a mobile substation cable fault positioning method, and relates to the technical field of mobile substation state monitoring and operation and maintenance, and the fault positioning method comprises the steps: obtaining cable first fault transient traveling wave data collected by a vehicle-mounted measurement and control system; obtaining coarse positioning information of a cable fault point according to the first fault transient traveling wave data of the cable; according to the parking fault-tolerant window of the cable fault point coarse positioning information, triggering a vehicle-mounted partial discharge detector to acquire second fault transient traveling wave data of the cable; and coupling the first cable fault transient traveling wave data, the second cable fault transient traveling wave data and the cable fault point coarse positioning information to obtain cable fault point fine positioning information. According to the fault positioning method, the technical problem that a traditional method is poor in precision and even fails in the short cable, high-resistance grounding and parameter time-varying scenes is thoroughly solved, a technical implementation basis is provided for subsequent closed-loop verification and meter-level and even sub-meter-level precise positioning, and the emergency power supply reliability and the emergency repair efficiency are remarkably improved.

Description

Technical Field

[0001] This application relates to the field of mobile substation condition monitoring and maintenance technology, and in particular to a method for locating cable faults in mobile substations. Background Technology

[0002] There are three main methods for locating cable faults in existing mobile substations: the traditional traveling wave method, the impedance method, and the offline manual partial discharge detection method. Among them: (1) The traditional traveling wave method mainly extracts the fault traveling wave head through the vehicle-mounted measurement and control device for single-end or double-end distance measurement; (2) The impedance method mainly uses the steady-state power frequency after the fault to calculate the fault distance; (3) Some high-end mobile substations are equipped with fixed UHF and ultrasonic partial discharge detectors, and after the substation is stopped, the manual person holds the instrument and searches for the discharge source along the cable; (4) A few fault location technology solutions attempt to introduce an online monitoring system, specifically by pre-embedding sensors in the middle joint of the cable to upload partial discharge signals in real time.

[0003] However, the aforementioned existing cable fault location methods are all designed for fixed substations and are difficult to widely adopt in practical applications of mobile substations, mainly due to the following problems:

[0004] The cable lines of mobile substations are short, have many branches, and the laying method and environmental parameters change drastically with each grid connection, resulting in: (1) the wave velocity of the traveling wave method is uncertain, the reflected wave head is difficult to identify, the positioning error is often tens to hundreds of meters, and the fault location result is relatively rough; (2) the impedance method is completely ineffective when the short line is grounded with high resistance; (3) although the fault location of the partial discharge detector is relatively more precise than the traveling wave method, the fixed partial discharge detector has the defect of a very small coverage range due to the limitation of the vehicle space, while the handheld partial discharge detector has the defects of low detection efficiency, long time consumption, and the need for personnel to enter the live area, which poses a safety risk; (4) the pre-embedded sensor technology solution is costly and complex to construct, and cannot be implemented in the cables temporarily laid for emergency repairs.

[0005] Moreover, existing technologies do not utilize the unique physical characteristic of mobile substations that they can still move accurately after a fault, resulting in a serious disconnect between coarse and fine positioning, making it difficult to provide a technical basis for subsequent closed-loop verification and the realization of meter-level or even sub-meter-level accurate positioning. Summary of the Invention

[0006] In order to solve the technical problems existing in the prior art, the purpose of this application is to provide a method for locating cable faults in mobile substations, which completely solves the technical problems of poor accuracy or even failure of traditional methods in scenarios with short cables, high resistance grounding, and time-varying parameters. This provides a technical basis for subsequent closed-loop verification and the realization of meter-level or even sub-meter-level accurate positioning, and significantly improves the reliability of emergency power supply and repair efficiency.

[0007] To achieve the aforementioned objectives, the technical solution adopted in this application is as follows:

[0008] A method for locating cable faults in a mobile substation includes:

[0009] Acquire the transient traveling wave data of the first cable fault collected by the vehicle-mounted measurement and control system;

[0010] Based on the transient traveling wave data of the first cable fault, coarse location information of the cable fault point is obtained;

[0011] Based on the parking fault tolerance window of the coarse location information of the cable fault point, the on-board partial discharge detector is triggered to collect the transient traveling wave data of the second fault of the cable.

[0012] By coupling the transient traveling wave data of the first cable fault, the transient traveling wave data of the second cable fault, and the coarse location information of the cable fault point, the fine location information of the cable fault point is obtained.

[0013] Preferably, acquiring the transient traveling wave data of the cable's first fault collected by the vehicle-mounted monitoring and control system further includes, prior to:

[0014] When the fault initiation criterion is met, freeze the transient waveform data before and after the fault.

[0015] More preferably, the fault initiation criterion includes at least one of the following: single-phase grounding fault, phase-to-phase short-circuit fault, latent fault where partial discharge develops into breakdown, open-circuit fault, or high-resistance grounding fault.

[0016] Furthermore, the transient traveling wave data of the cable during the first fault includes the neutral point resistance and current of the main transformer. and cable fault traveling wave data; the coarse location information of the cable fault point includes the coarse axial distance of the cable fault point. Based on the transient traveling wave data of the first cable fault, coarse location information of the cable fault point is obtained, including:

[0017] Based on the neutral point resistance and current of the main transformer Calculate the wave velocity saturation correction coefficient Wherein, the wave velocity saturation correction coefficient The calculation formula is:

[0018] ;

[0019] In the formula, The gain coefficient is the energy-wave velocity mapping coefficient. The width of the transient energy integration window. The transient energy decay rate is... This is the resistance value at the neutral point. This is the reference value for the neutral point zero-sequence voltage. For temperature periodic modulation amplitude, For the real-time temperature of the cable, This refers to the maximum permissible temperature of the cable.

[0020] Based on cable fault traveling wave data and wave velocity saturation correction factor Calculate the axial distance for coarse localization of cable fault points. The coarse axial distance for locating the cable fault point The calculation formula is: In the formula, The nominal wave velocity in the traveling wave data of cable faults. This refers to the arrival time of the initial wavefront of the traveling wave in the traveling wave data for cable faults. This represents the initial moment of the fault in the traveling wave data of the cable fault.

[0021] Preferably, the parking tolerance window for the coarse location information of the cable fault point includes a dynamic lateral tolerance. Based on the parking fault tolerance window of the coarse location information of the cable fault point, the on-board partial discharge detector is triggered to collect the transient traveling wave data of the second cable fault, including:

[0022] Based on wave speed saturation correction coefficient Coarse axial distance for locating cable fault points Calculate the dynamic lateral allowable deviation The dynamic lateral tolerance deviation The calculation formula is: ;

[0023] In the formula, The baseline lateral tolerance. The parking window retraction sensitivity coefficient. This is the historical bias penalty coefficient. This is a rough historical distance measurement for the same route. This represents the historical standard deviation of the coarse positioning distance;

[0024] Compare the actual lateral deviation of the mobile substation when it stops with the dynamic lateral allowable deviation. :

[0025] If the actual lateral deviation of the mobile substation during shutdown is not greater than the dynamic lateral allowable deviation. This triggers the on-board partial discharge detector to collect transient traveling wave data of the second fault in the cable.

[0026] Preferably, the cable second fault transient traveling wave data includes the arrival time of the UHF signal. Time of arrival of ultrasonic signal UHF signal strength and ultrasonic signal strength The precise location information of the cable fault point includes the axial distance of the precise location of the cable fault point. ;

[0027] By coupling the transient traveling wave data of the first cable fault, the transient traveling wave data of the second cable fault, and the coarse location information of the cable fault point, fine location information of the cable fault point is obtained, including:

[0028] According to the wave speed saturation correction coefficient and dynamic lateral tolerance Calculate coarse-fine coupling weights The coarse-fine coupling weights The calculation formula is:

[0029] In the formula, This is the coupling weight adjustment coefficient. The power exponent for parking deviation;

[0030] According to the arrival time of the ultra-high frequency signal Time of arrival of ultrasonic signal and current detection height Calculate the time difference for coarse positioning wave velocity correction. ; wherein, the time difference of the inherited coarse positioning wave velocity correction The calculation formula is:

[0031] In the formula, For wave speed correction index, To detect the severity of high penalties, This represents the current detection height of the vehicle-mounted partial discharge detector. The optimal detection height for vehicle-mounted partial discharge detectors. The height is Gaussian and the width is [missing information].

[0032] According to the coarse-fine coupling weight axial distance for coarse location of cable fault point Time difference inherited from coarse positioning wave velocity correction UHF signal strength Ultrasonic signal strength Calculate the axial distance for precise location of cable fault points. The axial distance for precise positioning of the cable fault point The calculation formula is:

[0033] ;

[0034] In the formula, For real-time speed of sound, This is the signal strength gain coefficient. The reference signal strength threshold;

[0035] The real-time speed of sound The calculation formula is: ,in, To measure ambient temperature for vehicle-mounted weather stations, The vehicle-mounted weather station measures the relative humidity of the environment.

[0036] Preferably, the mobile substation cable fault location method described in this application further includes:

[0037] Based on the precise location information of the cable fault point and the transient traveling wave data of the second cable fault, the confidence level of the precise location information of the cable fault point is calculated. ;

[0038] Compare the confidence levels of the precise location information of cable fault points Compared with the preset confidence threshold :

[0039] If the confidence level of the precise location information of the cable fault point Not less than the preset confidence threshold Then, the output cable fault location information and confidence report will be provided.

[0040] Preferably, the mobile substation cable fault location method of this application further includes:

[0041] If the confidence level of the precise location information of the cable fault point Less than the preset confidence threshold If so, the fine location information of the cable fault point is defined as the benchmark for the next coarse location of the cable fault point, and the historical experience database is updated with the current coarse location information and fine location information of the cable fault point.

[0042] Preferably, if the confidence level of the precise location information of the cable fault point is... Less than the preset confidence threshold Then return to the step of obtaining coarse location information of the cable fault point based on the transient traveling wave data of the first cable fault, until the confidence level of the fine location information of the cable fault point is reached. Not less than the preset confidence threshold This achieves forced convergence.

[0043] Preferably, the confidence level P of the cable fault location information is calculated using the following formula:

[0044] In the formula, This represents the confidence level steepness coefficient.

[0045] Compared with the prior art, this application has at least the following technical effects:

[0046] The mobile substation cable fault location method proposed in this application fully utilizes the unique characteristic of mobile substations that they can still be moved in a controlled manner after a fault. It combines the traditional passive coarse location method using traveling waves with the precise location method using active partial discharge after shutdown, solving the technical problems of low accuracy or even failure of traditional traveling wave and impedance methods in short-distance, multi-branch, and time-varying parameter cable scenarios. Moreover, it eliminates the need for pre-embedded expensive sensors, significantly reducing construction and maintenance costs. It can provide the repair end with accurate fault location, greatly shortening the emergency power restoration time. The entire process does not require personnel to work close to the energized area, greatly improving the safety level of repair personnel and possessing extremely high economic value and social benefits. At the same time, it also provides a technical foundation for subsequent closed-loop verification and the realization of meter-level or even sub-meter-level accurate location. Attached Figure Description

[0047] Figure 1 A flowchart of a preferred embodiment of the mobile substation cable fault location method of this application;

[0048] Figure 2 This is a schematic diagram of a preferred embodiment of the mobile substation cable fault location device of this application.

[0049] Figure 3 This is a schematic diagram of a preferred embodiment of an electronic device according to this application. Detailed Implementation

[0050] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present application are used to explain the present application, but are not intended to limit the present application. It should be noted that all directional indicators (such as up, down, left, right, front, back, upper end, lower end, top, bottom, etc.) in the embodiments of the present application are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indicator will also change accordingly.

[0051] In this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0052] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" and "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0053] The present application will be further described in detail below with reference to the accompanying drawings.

[0054] Figure 1 The diagram illustrates the cable fault location method for mobile substations described in this application. To achieve the aforementioned objectives, the technical solution employed in this application is as follows:

[0055] A method for locating cable faults in a mobile substation includes:

[0056] S1: Acquire the transient traveling wave data of the first cable fault collected by the vehicle-mounted measurement and control system;

[0057] S2: Based on the transient traveling wave data of the first cable fault, obtain coarse location information of the cable fault point;

[0058] S3: Based on the parking fault tolerance window of the coarse location information of the cable fault point, trigger the on-board partial discharge detector to collect the transient traveling wave data of the second fault of the cable.

[0059] S4: Couple the transient traveling wave data of the first cable fault, the transient traveling wave data of the second cable fault, and the coarse location information of the cable fault point to obtain the fine location information of the cable fault point.

[0060] The mobile substation cable fault location method proposed in this application fully utilizes the unique characteristic of mobile substations that they can still be moved in a controlled manner after a fault. It combines the traditional passive coarse location method using traveling waves with the precise location method using active partial discharge after shutdown, solving the technical problem of low accuracy or even failure of traditional traveling wave and impedance methods in short-distance, multi-branch, and time-varying parameter cable scenarios. Moreover, it eliminates the need for pre-embedded expensive sensors, significantly reducing construction and maintenance costs. It can provide the repair end with accurate fault location, greatly shortening the emergency power restoration time. The entire process does not require personnel to work close to the energized area, greatly improving the safety level of repair personnel. It has extremely high economic value and social benefits. At the same time, it also provides a technical foundation for subsequent closed-loop verification and achieving meter-level or even sub-meter-level accurate location.

[0061] In some embodiments, S1: Acquiring the transient traveling wave data of the cable first fault collected by the vehicle-mounted monitoring and control system, further including:

[0062] When the fault initiation criterion is met, freeze the transient waveform data before and after the fault.

[0063] Specifically, the fault initiation criteria include at least one of the following: single-phase grounding fault, phase-to-phase short-circuit fault, latent fault where partial discharge develops into breakdown, open-circuit fault, or high-resistance grounding fault.

[0064] Any of the above faults will generate a sufficiently strong initial wavefront and neutral point transient current of the traveling wave, thereby ensuring the wave velocity saturation correction factor. Coarse axial distance from cable fault point Effective calculations help improve the rough location accuracy of cable fault points.

[0065] In some embodiments, the transient traveling wave data of the cable first fault includes, but is not limited to, the three-phase voltage and current of each outgoing line, and the neutral point resistance and current of the main transformer. and cable fault traveling wave data; the coarse location information of the cable fault point includes the coarse axial distance of the cable fault point. S2: Based on the transient traveling wave data of the first cable fault, obtain coarse location information of the cable fault point, including:

[0066] Based on the neutral point resistance and current of the main transformer Calculate the wave velocity saturation correction coefficient Wherein, the wave velocity saturation correction coefficient The calculation formula is:

[0067] ;

[0068] In the formula, The gain coefficient is the energy-wave velocity mapping coefficient. The width of the transient energy integration window. The transient energy decay rate is... This is the resistance value at the neutral point. This is the reference value for the neutral point zero-sequence voltage. For temperature periodic modulation amplitude, For the real-time temperature of the cable, This refers to the maximum permissible temperature of the cable.

[0069] Based on cable fault traveling wave data and wave velocity saturation correction factor Calculate the axial distance for coarse localization of cable fault points. The coarse axial distance for locating the cable fault point The calculation formula is: In the formula, The nominal wave velocity in the traveling wave data of cable faults. This refers to the arrival time of the initial wavefront of the traveling wave in the traveling wave data for cable faults. This represents the initial moment of the fault in the traveling wave data of the cable fault.

[0070] In some embodiments, obtaining coarse location information of the cable fault point based on the transient traveling wave data of the first cable fault further includes:

[0071] The wave velocity saturation correction coefficient and the coarse axial distance of the cable fault point are encapsulated into the same data frame in real time and broadcast synchronously to the coarse and fine coupling weight calculation unit and the parking fault tolerance calculation unit through the vehicle bus, thereby ensuring that all subsequent steps use the completely consistent coarse location result of the cable fault point.

[0072] In some embodiments, the parking tolerance window for the coarse location information of the cable fault point includes a dynamic lateral tolerance. S3: Based on the parking fault tolerance window of the coarse location information of the cable fault point, trigger the on-board partial discharge detector to collect the transient traveling wave data of the second cable fault, including:

[0073] Based on wave speed saturation correction coefficient Coarse axial distance for locating cable fault points Calculate the dynamic lateral allowable deviation The dynamic lateral tolerance deviation The calculation formula is: ;

[0074] In the formula, The baseline lateral tolerance. The parking window retraction sensitivity coefficient. This is the historical bias penalty coefficient. This is a rough historical distance measurement for the same route. The historical standard deviation of the coarse positioning distance; the dynamic lateral tolerance. It enables the stopping accuracy of mobile substations to be directly controlled by the wave velocity correction amplitude and historical deviation of the coarse positioning traveling wave.

[0075] Compare the actual lateral deviation of the mobile substation when it stops with the dynamic lateral allowable deviation. :

[0076] If the actual lateral deviation of the mobile substation during shutdown is not greater than the dynamic lateral allowable deviation. This triggers the on-board partial discharge detector to collect transient traveling wave data of the second fault in the cable.

[0077] It should be noted that this only applies when the actual lateral deviation of the mobile substation during shutdown is less than or equal to the dynamic lateral allowable deviation. At that time, the mobile substation's vehicle body locks the brakes and applies the wave velocity saturation correction coefficient. axial distance for coarse location of cable fault point and dynamic lateral tolerance Forward to the coarse-fine coupled weight calculation unit to ensure that the weight allocation in the fine positioning stage is physically consistent with the actual parking accuracy.

[0078] It should be noted that by directly writing the real-time output dynamic lateral tolerance deviation into the RTK navigation fault tolerance radius register of the mobile substation, the vehicle body of the mobile substation can be forced to travel directly above the cable with the dynamic lateral tolerance deviation as a constraint.

[0079] In some embodiments, the cable second fault transient traveling wave data includes the arrival time of the UHF signal. Time of arrival of ultrasonic signal UHF signal strength and ultrasonic signal strength The precise location information of the cable fault point includes the axial distance of the precise location of the cable fault point. ;

[0080] S4: Couple the transient traveling wave data of the first cable fault, the transient traveling wave data of the second cable fault, and the coarse location information of the cable fault point to obtain the fine location information of the cable fault point, including:

[0081] According to the wave speed saturation correction coefficient and dynamic lateral tolerance Calculate coarse-fine coupling weights The coarse-fine coupling weights The calculation formula is:

[0082] In the formula, This is the coupling weight adjustment coefficient. The power exponent for parking deviation;

[0083] According to the arrival time of the ultra-high frequency signal Time of arrival of ultrasonic signal and current detection height Calculate the time difference for coarse positioning wave velocity correction. ; wherein, the time difference of the inherited coarse positioning wave velocity correction The calculation formula is:

[0084] In the formula, For wave speed correction index, To detect the severity of high penalties, This represents the current detection height of the vehicle-mounted partial discharge detector. The optimal detection height for vehicle-mounted partial discharge detectors. The height is Gaussian and the width is [missing information].

[0085] According to the coarse-fine coupling weight axial distance for coarse location of cable fault point Time difference inherited from coarse positioning wave velocity correction UHF signal strength Ultrasonic signal strength Calculate the axial distance for precise location of cable fault points. The axial distance for precise positioning of the cable fault point The calculation formula is:

[0086] ;

[0087] In the formula, For real-time speed of sound, This is the signal strength gain coefficient. The reference signal strength threshold;

[0088] The real-time speed of sound The calculation formula is: ,in, To measure ambient temperature for vehicle-mounted weather stations, The vehicle-mounted weather station measures the relative humidity of the environment.

[0089] It should be noted that the data collected by the vehicle-mounted partial discharge detector regarding the transient traveling wave of the second fault in the cable specifically refers to:

[0090] The mobile substation confirms that its actual lateral deviation during shutdown is less than or equal to the dynamic lateral allowable deviation. At that time, the mobile substation locks onto the vehicle body and uses the vehicle body coordinates as the scanning origin to measure the real-time ultra-high frequency signal strength, ultrasonic signal strength, and the current detection height of the onboard partial discharge detector. It is sent to the input time difference correction unit at the same time.

[0091] In some embodiments, the mobile substation cable fault location method described in this application further includes:

[0092] S5: Calculate the confidence level of the cable fault location information based on the precise location information of the cable fault point and the transient traveling wave data of the second cable fault. ;

[0093] Compare the confidence levels of the precise location information of cable fault points Compared with the preset confidence threshold :

[0094] If the confidence level of the precise location information of the cable fault point Not less than the preset confidence threshold Then, the output cable fault location information and confidence report will be provided.

[0095] In some embodiments, the mobile substation cable fault location method of this application further includes:

[0096] If the confidence level of the precise location information of the cable fault point Less than the preset confidence threshold If so, the fine location information of the cable fault point is defined as the benchmark for the next coarse location of the cable fault point, and the historical experience database is updated with the current coarse location information and fine location information of the cable fault point.

[0097] Synchronously or asynchronously, if the confidence level of the precise location information of the cable fault point... Less than the preset confidence threshold Then return to the step of obtaining coarse location information of the cable fault point based on the transient traveling wave data of the first cable fault, until the confidence level of the fine location information of the cable fault point is reached. Not less than the preset confidence threshold This achieves forced convergence.

[0098] Specifically, the formula for calculating the confidence level P of the precise location information of the cable fault point is as follows:

[0099] In the formula, This represents the confidence level steepness coefficient.

[0100] By setting up a confidence-based closed-loop iteration mechanism (specifically, a forced closed-loop iteration mechanism), the coarse positioning guides the mobile substation to actively approach the cable fault point once or multiple times, and the fine positioning result corrects the target closed-loop process for the next movement. Ultimately, this achieves sub-meter-level accurate positioning of medium-voltage cable faults across all scenarios and outputs confidence scores, significantly improving the reliability of emergency power supply and the efficiency of emergency repairs.

[0101] Figure 2 This is a preferred embodiment of the mobile substation cable fault location device of this application, which includes:

[0102] The first acquisition module is used to acquire the transient traveling wave data of the first cable fault collected by the vehicle-mounted measurement and control system;

[0103] The first processing module is used to obtain coarse location information of the cable fault point based on the transient traveling wave data of the first cable fault.

[0104] The second acquisition module is used to trigger the on-board partial discharge detector to acquire the transient traveling wave data of the second fault of the cable based on the parking fault tolerance window of the coarse location information of the cable fault point.

[0105] The second processing module is used to couple the transient traveling wave data of the first cable fault, the transient traveling wave data of the second cable fault, and the coarse location information of the cable fault point to obtain the fine location information of the cable fault point.

[0106] The third processing module is used to calculate the confidence level of the cable fault location information based on the cable fault location information and the transient traveling wave data of the second cable fault; compare the confidence level of the cable fault location information with the preset confidence threshold; if the confidence level of the cable fault location information is not less than the preset confidence threshold, then output the cable fault location information and confidence report.

[0107] The various modules of the aforementioned mobile substation cable fault location device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device described in this application can be divided into different functional units or modules to complete all or part of the functions described above.

[0108] Figure 3 This application provides an electronic device, which can be a server. The electronic device includes a processor, memory, and a communication interface connected via a system bus. The processor provides computing and control capabilities. The memory can be implemented using any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: disks, optical disks, EEPROMs, EPROMs, SRAMs, ROMs, magnetic storage, flash memory, and PROMs. The memory provides an environment for the operation of the operating system and computer programs stored within it. The communication interface is a network interface used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the steps of the mobile substation cable fault location method described in the above embodiments.

[0109] This application also provides a computer-readable storage medium storing a computer program / instructions thereon, which, when executed by a processor, implements the steps of the mobile substation cable fault location method described in the above embodiments. This computer-readable storage medium includes, but is not limited to, ROM, RAM, CD-ROM, magnetic disk, and floppy disk.

[0110] This application also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the steps of the mobile substation cable fault location method described in the above embodiments.

[0111] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A mobile substation cable fault location method, characterized by, The method comprises the following steps: Obtaining cable first fault transient traveling wave data collected by a vehicle-mounted measurement and control system; Obtaining cable fault point coarse positioning information according to the cable first fault transient traveling wave data; Triggering a vehicle-mounted partial discharge detector to collect cable second fault transient traveling wave data according to a parking fault tolerance window of the cable fault point coarse positioning information; Coupling the cable first fault transient traveling wave data, the cable second fault transient traveling wave data and the cable fault point coarse positioning information to obtain cable fault point fine positioning information.

2. The mobile substation cable fault location method of claim 1, wherein, The method further comprises the following steps before obtaining the cable first fault transient traveling wave data collected by the vehicle-mounted measurement and control system: Freezing transient recording data before and after the fault when a fault starting criterion is met.

3. The mobile substation cable fault location method of claim 2, wherein, The fault starting criterion at least includes any one of single-phase ground fault, phase-to-phase short circuit fault, latent fault of partial discharge developing into breakdown, and non-grounded or high-resistance grounded line breakage.

4. The mobile substation cable fault location method of any of claims 1-3, wherein, The cable first fault transient traveling wave data includes a main transformer neutral point resistance current and cable fault traveling wave data; the cable fault point coarse positioning information includes a cable fault point coarse positioning axial distance ; The method further comprises the following steps of obtaining the cable fault point coarse positioning information according to the cable first fault transient traveling wave data: According to the resistance current of the neutral point of the main transformer , a wave velocity saturation correction coefficient is calculated ; wherein the calculation formula of the wave velocity saturation correction coefficient is: ； wherein, is an energy-wave velocity mapping gain coefficient, is a transient energy integration window width, is a transient energy exponential decay rate, is a neutral point resistance value, is a neutral point zero sequence voltage reference value, is a temperature periodic modulation amplitude, is a cable real-time temperature, is a cable maximum allowable temperature; According to the cable fault traveling wave data and the wave velocity saturation correction coefficient , the cable fault point rough positioning axial distance is calculated ; the calculation formula of the cable fault point rough positioning axial distance is: ; in the formula, is the nominal wave velocity in the cable fault traveling wave data, is the traveling wave initial wave head arrival time in the cable fault traveling wave data, is the fault initial time in the cable fault traveling wave data.

5. The mobile substation cable fault location method of claim 4, wherein, The parking fault-tolerant window of the cable fault point rough positioning information includes a dynamic lateral allowable deviation ; The method further comprises the following steps of triggering the vehicle-mounted partial discharge detector to collect the cable second fault transient traveling wave data according to the parking fault tolerance window of the cable fault point coarse positioning information: According to the wave velocity saturation correction coefficient And the cable fault point rough positioning axial distance , calculate the dynamic lateral allowable deviation ; The calculation formula of the dynamic lateral allowable deviation is: ; wherein, is the reference lateral tolerance, is the parking window contraction sensitivity coefficient, is the historical deviation penalty coefficient, is the historical coarse positioning distance on the same line, is the coarse positioning distance historical standard deviation; comparing the actual parking lateral deviation of the mobile substation with the dynamic lateral deviation tolerance : If the actual parking lateral deviation of the mobile substation is not greater than the dynamic lateral allowable deviation Then trigger the on-board partial discharge detector to collect the cable second fault transient traveling wave data.

6. The mobile substation cable fault location method of claim 5, wherein, The cable second fault transient traveling wave data includes the arrival time of the ultra-high frequency signal , the arrival time of the ultrasonic signal , the intensity of the ultra-high frequency signal , and the intensity of the ultrasonic signal ; and the cable fault point fine positioning information includes the cable fault point fine positioning axial distance ; The method further comprises the following steps of coupling the cable first fault transient traveling wave data, the cable second fault transient traveling wave data and the cable fault point coarse positioning information to obtain the cable fault point fine positioning information: According to the wave velocity saturation correction coefficient and dynamic lateral tolerance , calculate the coarse-fine coupling weight , wherein the coarse-fine coupling weight The calculation formula is: ; wherein is a coupling weight adjustment factor, is a parking deviation power index; According to the time of arrival of the very high frequency signal , the time of arrival of the ultrasonic signal , and the current detection height , a time difference of inherited coarse positioning wave velocity correction is calculated ; wherein the calculation formula of the time difference of inherited coarse positioning wave velocity correction is: ; wherein, is a wave speed correction index, is a detection height penalty magnitude, is a current detection height of the on-board partial discharge detector; is an optimal detection height of the on-board partial discharge detector, is a height Gaussian width; According to the coarse-fine coupling weight , cable fault point coarse positioning axial distance , time difference of inheriting coarse positioning wave velocity correction , ultra-high frequency signal strength , ultrasonic signal strength , calculating cable fault point fine positioning axial distance ; the calculation formula of the cable fault point fine positioning axial distance is: ； In the formula, is a real-time sound speed, is a signal intensity gain coefficient, is a reference signal intensity threshold; the real-time sound speed The calculation formula is: Wherein, is the ambient temperature measured by the vehicle-mounted meteorological station, The relative humidity of the environment measured by the vehicle-mounted meteorological station.

7. The mobile substation cable fault location method of claim 6, wherein, The method further comprises the following steps: According to the cable fault point fine positioning information and the cable second fault transient traveling wave data, a confidence degree of the cable fault point fine positioning information is calculated ; Comparing confidence of cable fault point fine positioning information with a pre-set confidence threshold : If the confidence level of the cable fault point fine positioning information is not less than a preset confidence threshold not less than a preset confidence threshold then output the cable fault point fine positioning information and the confidence report.

8. The mobile substation cable fault location method of claim 7, wherein, The method further comprises the following steps: If the confidence level of the precise location information of the cable fault point Less than the preset confidence threshold If so, the fine location information of the cable fault point is defined as the benchmark for the next coarse location of the cable fault point, and the historical experience database is updated with the current coarse location information and fine location information of the cable fault point.

9. The mobile substation cable fault location method of claim 7, wherein, If the confidence level of the precise location information of the cable fault point Less than the preset confidence threshold Then return to the step of obtaining coarse location information of the cable fault point based on the transient traveling wave data of the first cable fault, until the confidence level of the fine location information of the cable fault point is reached. Not less than the preset confidence threshold This achieves forced convergence.

10. The mobile substation cable fault location method of claim 7, wherein, The calculation formula of the confidence degree P of the cable fault point fine positioning information is: ; where is a confidence steepness coefficient.

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