An electric power cable fault trench-in positioning system and method

Abstract

The application discloses a power cable fault trench in-position system, which comprises a pulse generator, a reference measuring station and a mobile measuring station; the pulse generator periodically applies a pulse signal to a power cable to excite a sound signal emitted by a fault point of the power cable; the reference measuring station obtains a first coordinate position where the reference measuring station is located, a first magnetic signal, a vibration signal and a sound signal which are time-stamped, and sends the first coordinate position, the first magnetic signal, the vibration signal and the sound signal which are time-stamped to the mobile measuring station; the mobile measuring station establishes communication with the reference measuring station after being fixed each time, obtains a second coordinate position where the mobile measuring station is located each time, a second magnetic signal, a vibration signal and a sound signal which are time-stamped, and determines a final position of the fault point in combination with the first coordinate position where the reference measuring station is located, the first magnetic signal, the vibration signal and the sound signal which are time-stamped. The application has the advantages of good stability, high positioning precision, fast positioning speed and the like, and reduces manpower checking and trench digging.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a system and method for locating power cable faults in trenches. Background Technology

[0002] Power cables are a crucial component of power systems and a vital guarantee for modern national economic development and people's lives. Especially in densely populated urban areas, the scale of power cable laying has become increasingly massive with the expansion of urbanization. To conserve limited urban land and maintain environmental aesthetics, most power cables are buried underground or in cable trenches, becoming the primary method of cable laying. As their service life extends, power cable faults are inevitable. While regular safety inspections and troubleshooting can effectively reduce the probability of cable failures, the inability to promptly locate fault points when they occur can cause significant inconvenience and economic losses to surrounding factories and residents. Therefore, power cable managers need to be able to quickly and accurately locate faulty cables to improve the reliability of power supply and reduce losses and maintenance costs. Thus, rapid and accurate power cable fault location not only has practical social significance but also possesses engineering value.

[0003] The environment in which buried power cables are located is relatively complex, making fault detection and location relatively difficult. The steps for power cable fault detection can be divided into three parts: determining the nature of the cable fault, roughly measuring the fault distance, tracing the path of the faulty power cable, and precisely pinpointing the location. Precise pinpointing means restricting the location of the fault to a very small area, thus avoiding the impact of large-scale excavation on surrounding areas and other pipelines, while improving the efficiency of fault removal.

[0004] However, current methods for troubleshooting power cable faults still rely mainly on the primitive method of manually digging trenches to check each fault one by one. Even with the support of more advanced sound-detection and fault-finding devices, it is still impossible to quickly and accurately locate the fault point of the power cable.

[0005] Therefore, there is an urgent need for a power cable fault location method that is stable, accurate, and fast, so as to reduce manpower for troubleshooting and trenching. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a power cable fault trench location system and method, which has the advantages of good stability, high positioning accuracy and fast positioning speed, and can reduce manpower for inspection and trench excavation.

[0007] To address the aforementioned technical problems, embodiments of the present invention provide a system for implementing a power cable fault trench location system, comprising a pulse generator, a reference measuring station, and a moving measuring station; wherein...

[0008] The pulse generator is applied to the power cable within the cable trench;

[0009] The reference measurement station is fixedly installed in the cable trench; the reference measurement station is equipped with a first satellite signal receiver, a first wireless communication module, and a first electromagnetic sensor, a first vibration sensor, and a first microphone, all of which are connected to the power cable.

[0010] The mobile measuring station is installed in the cable trench, and after each installation, it maintains a certain distance from the reference measuring station and establishes communication with the reference measuring station. The mobile measuring station is equipped with a second satellite signal receiver, a second wireless communication module, a data calculation module, and a second electromagnetic sensor, a second vibration sensor, and a second microphone, all connected to the power cable. The second wireless communication module of the mobile measuring station and the first wireless communication module of the reference measuring station achieve communication interconnection and establishment.

[0011] The pulse generator is used to periodically apply a high-voltage DC pulse signal to the power cable so that when there is a fault point in the power cable, it can excite the fault point to emit a sound signal.

[0012] The reference measurement station is used to obtain its own first coordinate position based on the satellite using the first satellite signal receiver, and to timestamp the first magnetic signal, first vibration signal and first sound signal generated when the power cable is subjected to a high voltage DC pulse signal by the pulse generator, which are respectively collected in real time by the first electromagnetic sensor, the first vibration sensor and the first microphone. Furthermore, the first wireless communication module is used to send the obtained first coordinate position and the timestamped first magnetic signal, first vibration signal and first sound signal to the mobile measurement station.

[0013] The mobile measuring station, when establishing communication with the reference measuring station after each installation and fixation activity, uses the second satellite signal receiver to obtain its second coordinate position after each installation and fixation activity, based on the satellite. It also timestamps the second magnetic signal, second vibration signal, and second sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator, which are respectively collected in real time by the second electromagnetic sensor, the second vibration sensor, and the second microphone. Furthermore, it uses the second wireless communication module to receive the first coordinate position and the timestamped first magnetic signal, first vibration signal, and first sound signal sent by the reference measuring station.

[0014] Based on the second coordinate position obtained after each installation and fixing, as well as the second magnetic signal, second vibration signal, and second sound signal with timestamps, and combined with the first coordinate position, first magnetic signal, first vibration signal, and first sound signal received from the reference measuring station each time, the final location of the fault point in the power cable is determined using the data calculation module.

[0015] The mobile measurement station and the reference measurement station form an RTK system using the satellite, the first satellite signal receiver, and the second satellite signal receiver.

[0016] The data calculation module includes:

[0017] The ranging start time determination submodule is used to determine the total number of times the mobile measuring station establishes communication with the reference measuring station after its mobile installation and fixation, which is k. Based on the second magnetic signal with timestamps collected by the mobile measuring station from the 1st to the kth times, or the first magnetic signal with timestamps collected by the reference measuring station from the 1st to the kth times, the module extracts k start times corresponding to the synchronous measurement of magnetic signals, vibration signals, and sound signals between the mobile measuring station and the reference measuring station from the 1st to the kth times; where k is a positive integer greater than 1.

[0018] The first time-of-flight ranging submodule is used to extract k end times corresponding to the second vibration signal measured by the mobile measuring station in 1 to k times and the first vibration signal measured by the reference measuring station in 1 to k times, based on the second vibration signal with timestamps collected by the mobile measuring station in 1 to k times and the first vibration signal with timestamps collected by the reference measuring station in 1 to k times. It also estimates k first propagation velocities of the vibration signal when it flies in the power cable by combining the first coordinate position obtained by the reference measuring station in 1 to k times and the second coordinate position obtained by the mobile measuring station in 1 to k times. Furthermore, it calculates the k first flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively in 1 to k times based on the flight time of the vibration signal, based on the k times collected by the ranging start time determination submodule in 1 to k times.

[0019] The first intensity ranging submodule is used to fit k first intensity ranging distances obtained by the mobile measuring station and the reference measuring station based on the second vibration signal with timestamps collected 1 to k times by the mobile measuring station and the first vibration signal with timestamps collected 1 to k times by the reference measuring station, using a preset first received signal intensity model.

[0020] The second time-of-flight ranging submodule is used to extract k end times corresponding to the second sound signals measured by the mobile measuring station in 1 to k times and the first sound signals measured by the reference measuring station in 1 to k times, based on the second sound signals with timestamps collected by the mobile measuring station in 1 to k times and the first sound signals with timestamps collected by the reference measuring station in 1 to k times. It also estimates k second propagation velocities of the sound signal when it flies in the power cable by combining the first coordinate position obtained by the reference measuring station in 1 to k times and the second coordinate position obtained by the mobile measuring station in 1 to k times. Furthermore, it calculates k second flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively in 1 to k times based on the flight time of the sound signal in the air, based on the k times extracted by the ranging start time determination submodule in 1 to k times.

[0021] The second intensity ranging submodule is used to fit the second time-stamped sound signals collected by the mobile measuring station from 1 to k times and the first time-stamped sound signals collected by the reference measuring station from 1 to k times using a preset second received signal intensity model to obtain k second intensity ranging distances obtained by the mobile measuring station and the reference measuring station respectively from 1 to k times based on the intensity of the sound signals in the air.

[0022] The third time-of-flight ranging submodule is used to perform noise filtering on the second sound signal with timestamps collected by the mobile measuring station from the first to the second time-of-flight collected by the reference measuring station from the first to the second time-of-flight ... reference measuring station from the first to the second time-of-flight collected by the mobile measuring station from the first to the second time-of-flight collected by the mobile measuring station from the first to the second time-of-flight collected by the mobile measuring station from the first to the second time-of-flight collected by the mobile measuring station from the first to the second time-of-flight collected by the mobile measuring station from the first to the second time-of-flight collected by the mobile measuring station from the first to the second time-of-

[0023] The third intensity ranging submodule is used to fit k third intensity ranging distances of the mobile measuring station and the reference measuring station in the power cable based on the second sound signal after filtering from the mobile measuring station 1 to k times and the first sound signal after filtering from the reference measuring station 1 to k times, using a preset third received signal intensity model.

[0024] The fault location submodule is used to construct an objective function based on the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained by the mobile measuring station from 1 to k times, and the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained by the reference measuring station from 1 to k times, and in combination with six preset weighting weights. The optimal solution of the objective function is obtained by using the particle swarm optimization algorithm and the Levenberg-Marquardt algorithm. The output of the optimal solution is the final location of the fault point in the power cable.

[0025] Wherein, the objective function is in,

[0026] The estimated location of the fault point in the power cable is given by: p, where p is the quantity to be estimated for the fault point location; the superscript j represents the number of measurements, and j = 1, 2, ..., k; the subscript r represents the reference measurement station; the subscript m represents the mobile measurement station; d represents the distance; the subscript i represents the type of measurement distance; w i Represents the i-th weighted weight, and This represents the first flight ranging distance obtained by the reference measuring station in the k-th corresponding measurement. This represents the first flight ranging distance obtained by the mobile measuring station in the k-th corresponding measurement. This represents the first intensity ranging distance obtained by the reference measuring station in the k-th measurement. This represents the first intensity ranging distance obtained by the mobile measuring station in the k-th measurement. This represents the second flight ranging distance obtained by the reference measuring station in the k-th iteration. This represents the second flight ranging distance obtained by the mobile measuring station in the k-th iteration. This represents the second intensity ranging distance obtained by the reference measuring station in the k-th measurement. This represents the second intensity ranging distance obtained by the mobile measuring station in the k-th measurement. This represents the third flight ranging distance obtained by the reference measuring station in the k-th iteration. This represents the third flight ranging distance obtained by the mobile measuring station in the kth corresponding time. This represents the third intensity ranging distance obtained by the reference measuring station in the k-th measurement. This represents the third intensity ranging distance obtained by the mobile measuring station in the kth iteration.

[0027] Among them, through the formula The first flight ranging distance obtained by the reference measuring station in the kth corresponding time was calculated. The first flight ranging distance obtained by the mobile measuring station in the kth corresponding time. in,

[0028] The velocity of the vibration signal corresponding to the k-th propagation as it travels through the power cable represents the first propagation velocity. This represents the first coordinate position of the reference measuring station obtained in the k-th measurement. This represents the second coordinate position of the mobile measuring station obtained in the k-th measurement.

[0029] By using the threshold method, we obtain This represents the first vibration signal measured by the reference measuring station in the k-th measurement. This represents the k-th measurement of the first vibration signal by the reference measuring station. At the end of the day, This represents the second vibration signal measured by the mobile measuring station in the k-th measurement. This represents the second vibration signal measured by the mobile measuring station in the kth corresponding time. At the end of the time, f v A fixed threshold parameter;

[0030] By using the threshold method, we obtain This represents the first magnetic signal measured by the reference measuring station in the k-th measurement. f represents the starting time when the reference measuring station and the mobile measuring station simultaneously measure the magnetic signal, vibration signal, and sound signal for the kth time. e It is a fixed threshold parameter.

[0031] Among them, through the formula The second flight ranging distance obtained by the reference measuring station in the kth iteration is calculated. and the second flight ranging distance obtained by the mobile measuring station in the kth corresponding time. in,

[0032] This represents the second propagation speed of a sound signal during its k-th flight through the air, and

[0033] By using the threshold method, we obtain This represents the first sound signal measured by the reference measuring station in the k-th measurement. This represents the k-th corresponding measurement of the first sound signal by the reference measuring station. At the end of the day, This represents the second sound signal measured by the mobile measuring station in the kth corresponding measurement. This represents the k-th corresponding measurement of the second sound signal by the mobile measuring station. At the end of the time, f s It is a fixed threshold parameter.

[0034] Among them, through the formula The third flight ranging distance obtained by the reference measuring station in the kth corresponding calculation is obtained. and the third flight ranging distance obtained by the mobile measuring station in the kth corresponding time. in,

[0035] This represents the third propagation speed of the sound signal corresponding to the kth time as it travels through the power cable, and

[0036] By using the threshold method, we obtain This represents the first sound signal measured by the reference measuring station in the kth corresponding measurement. The sound signal obtained after noise filtering This represents the reference measuring station filtering the first sound signal for the kth time. The obtained sound signal At the end of the day, This represents the second sound signal measured by the mobile measuring station in the kth corresponding measurement. The sound signal obtained after noise filtering This represents the k-th time the mobile measuring station corresponds to the second sound signal. The obtained sound signal At the end of the time, f p It is a fixed threshold parameter.

[0037] Among them, through the formula Calculate the first intensity ranging distance obtained by the reference measuring station in the kth corresponding measurement.

[0038] Through formula The first intensity ranging distance obtained by the mobile measuring station in the kth corresponding measurement is calculated.

[0039] Through formula Calculate the second intensity ranging distance obtained by the reference measuring station in the kth measurement.

[0040] Through formula The second intensity ranging distance obtained by the mobile measuring station in the kth measurement is calculated.

[0041] Through formula Calculate the third intensity ranging distance obtained by the reference measuring station in the kth measurement.

[0042] Through formula The third intensity ranging distance obtained by the mobile measuring station in the kth iteration is calculated.

[0043] Among them, g v (·) represents the preset first received signal strength model, g s,1 (·) represents the preset second received signal strength model, g s,2 (·) represents the preset third received signal strength model, and all three received signal strength models are functions of signal strength and distance and are fitted by specific experiments.

[0044] This invention also provides a method for locating power cable faults in a trench, implemented on the aforementioned power cable fault trench location system. The method includes the following steps:

[0045] The pulse generator periodically applies a high-voltage DC pulse signal to the power cable so that when there is a fault point in the power cable, it can excite the fault point to emit a sound signal.

[0046] The reference measuring station obtains its own first coordinate position and timestamps the first magnetic signal, first vibration signal and first sound signal generated when the power cable is subjected to a high voltage DC pulse signal by the pulse generator. Furthermore, the obtained first coordinate position and the timestamped first magnetic signal, first vibration signal and first sound signal are sent to the mobile measuring station.

[0047] When the mobile measuring station establishes communication with the reference measuring station after each installation and fixation, it obtains its second coordinate position after each installation and fixation, and timestamps the second magnetic signal, second vibration signal, and second sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator. Combined with the first coordinate position received from the reference measuring station each time, as well as the timestamped first magnetic signal, first vibration signal, and first sound signal, the final location of the fault point in the power cable is determined.

[0048] The specific steps for determining the final location of the fault point in the power cable after each installation and fixation of the mobile measuring station, when establishing communication with the reference measuring station, include: obtaining the second coordinate position of the mobile measuring station after each installation and fixation, and timestamping the second magnetic signal, second vibration signal, and second sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator. These steps are combined with the first coordinate position received from the reference measuring station each time, along with the timestamped first magnetic signal, first vibration signal, and first sound signal.

[0049] The total number of times the mobile measuring station establishes communication with the reference measuring station after its mobile installation and fixation is determined to be k. Based on the second magnetic signal with timestamps collected by the mobile measuring station from 1 to k times or the first magnetic signal with timestamps collected by the reference measuring station from 1 to k times, k starting times corresponding to the synchronous measurement of magnetic signals, vibration signals and sound signals between the mobile measuring station and the reference measuring station are extracted from 1 to k times; where k is a positive integer greater than 1.

[0050] Based on the second vibration signal with timestamps collected by the mobile measuring station from the 1st to the kth times and the first vibration signal with timestamps collected by the reference measuring station from the 1st to the kth times, the k end times of the second vibration signal measured by the mobile measuring station from the 1st to the kth times and the k end times of the first vibration signal measured by the reference measuring station from the 1st to the kth times are extracted. Combined with the first coordinate position obtained by the reference measuring station from the 1st to the kth times and the second coordinate position obtained by the mobile measuring station from the 1st to the kth times, the k first propagation velocities of the vibration signal when it flies in the power cable are estimated. Furthermore, combined with the k start times extracted from the 1st to the kth times, the k first flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively in the 1st to the kth times based on the flight time of the vibration signal are calculated.

[0051] Based on the second vibration signal with timestamps collected by the mobile measuring station from 1 to k times and the first vibration signal with timestamps collected by the reference measuring station from 1 to k times, the k first intensity ranging distances obtained by the mobile measuring station and the reference measuring station respectively in 1 to k times based on the intensity of the vibration signal are fitted using a preset first received signal intensity model.

[0052] Based on the second sound signals with timestamps collected by the mobile measuring station from the first to the second time from the first to the second time from the second time from the first to the second time from the second time from the first to the second time from the second time from the first time from the second time from the first time from the second time from the first time from the second time from the first time from the second time from the first time from the second time from the first time from the first time from the second time from the first time from the second time from the first time from the second time from the first time from the first time from the second time from the first time from the second time from the first time from the first time from the second time from the first time from the second time from the first time to the second time from the first time from the second time from the first time to the second time from the third time from the first time, the k second propagation speeds of the sound signals when flying in the power cable are estimated. Furthermore, based on the k start times extracted from the first to the second time from the first time from the first time, the k second flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively in the first to the second time from the first time based on the flight time of the sound signals in the air are calculated.

[0053] Based on the second time-stamped sound signals collected by the mobile measuring station from 1 to k times and the first time-stamped sound signals collected by the reference measuring station from 1 to k times, the k second intensity ranging distances obtained by the mobile measuring station and the reference measuring station respectively from 1 to k times based on the intensity of the sound signals in the air are fitted using a preset second received signal strength model.

[0054] Using a pre-defined multipath cancellation technique, noise filtering is applied to the second, timestamped sound signals collected by the mobile measuring station from times 1 to k and the first, timestamped sound signals collected by the reference measuring station from times 1 to k. Further, k end times of the filtered second sound signals collected by the mobile measuring station from times 1 to k and k end times of the filtered first sound signals collected by the reference measuring station from times 1 to k are extracted. Combined with the first coordinate positions obtained by the reference measuring station from times 1 to k and the second coordinate positions obtained by the mobile measuring station from times 1 to k, k third propagation velocities of the sound signals during flight in the power cable after filtering are estimated. Furthermore, combined with the k start times extracted from times 1 to k, k third flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively during the flight time of the sound signals in the power cable from times 1 to k are calculated.

[0055] Based on the second sound signal filtered by the mobile measuring station from 1 to k times and the first sound signal filtered by the reference measuring station from 1 to k times, the k third intensity ranging distances of the mobile measuring station and the reference measuring station in the power cable from 1 to k times are obtained by fitting using a preset third received signal strength model.

[0056] Based on the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained from the mobile measuring station in 1 to k corresponding times, and the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained from the reference measuring station in 1 to k corresponding times, and combined with six preset weighting weights, an objective function is constructed. The particle swarm optimization algorithm and the Levenberg-Marquardt algorithm are used to find the optimal solution of the objective function, and the output of the optimal solution is the final location of the fault point in the power cable.

[0057] Implementing the embodiments of the present invention has the following beneficial effects:

[0058] 1. This invention can quickly locate power cable faults based on satellite, vibration signals, magnetic signals and sound signals, thereby enabling rapid and accurate location of power cable fault points in the complex environment of cable trenches in cities. It provides tools and means for the safe operation and risk management of power cables. Therefore, it has advantages such as good stability, high positioning accuracy and fast positioning speed, and can reduce the need for manpower to investigate and dig trenches.

[0059] 2. This invention utilizes satellites to form an RTK system with a reference measurement station and a mobile measurement station, thereby obtaining high-precision position information. Based on the coordinate information of the reference measurement station and the mobile measurement station, the propagation speed of vibration and sound signals in power cables and the propagation speed of sound signals in the atmosphere are calibrated in real time, thereby improving the accuracy of distance estimation.

[0060] 3. This invention transforms the fault location estimation problem in the objective function into a nonlinear weighted least squares problem, and then uses a heuristic algorithm to solve it, thereby gradually improving the fault location accuracy. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0062] Figure 1 This is a schematic diagram of a power cable fault trench location system provided in an embodiment of the present invention;

[0063] Figure 2A schematic diagram of the functional structure of a reference measuring station in a power cable fault trench location system provided in an embodiment of the present invention;

[0064] Figure 3 This is a functional structure diagram of a mobile measuring station in a power cable fault trench location system provided by an embodiment of the present invention;

[0065] Figure 4 This is a functional structure diagram of the data calculation module contained in a mobile measuring station in a power cable fault trench positioning system provided by an embodiment of the present invention;

[0066] Figure 5 This is a schematic diagram illustrating an application scenario of a power cable fault trench location system provided in an embodiment of the present invention.

[0067] Figure 6 A flowchart of a method for locating power cable faults in a trench, provided as an embodiment of the present invention. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0069] like Figures 1 to 3 As shown in the embodiment of the present invention, a power cable fault trench location system includes a pulse generator 1, a reference measuring station 2, and a mobile measuring station 3; wherein,

[0070] Pulse generator 1 is applied to power cable L inside the cable trench;

[0071] Reference measuring station 2 is fixedly installed inside the cable trench; such as Figure 2 As shown, the reference measurement station 2 is equipped with a first satellite signal receiver 21, a first wireless communication module 22, and a first electromagnetic sensor 23, a first vibration sensor 24 and a first microphone 25, all of which are connected to the power cable L.

[0072] The mobile measuring station 3 is installed within the cable trench, and after each installation, it maintains a certain distance from the reference measuring station 2 and establishes communication with it; for example... Figure 3 As shown, the mobile measurement station 3 is equipped with a second satellite signal receiver 31, a second wireless communication module 32, a data calculation module 36, and a second electromagnetic sensor 33, a second vibration sensor 34, and a second microphone 35, all of which are connected to the power cable L. The second wireless communication module 32 of the mobile measurement station 3 and the first wireless communication module 22 of the reference measurement station 2 achieve communication interconnection and establishment.

[0073] At this time, the pulse generator 1 is used to periodically (e.g., once every 30 seconds) apply a high-voltage DC pulse signal to the power cable L so that when there is a fault point in the power cable L, the fault point (not shown) can be excited to emit a sound signal.

[0074] Reference station 2 is used to obtain its own first coordinate position based on satellite (such as Beidou satellite) using the first satellite signal receiver 21, and to timestamp the first magnetic signal, first vibration signal and first sound signal generated when the power cable L is subjected to a high voltage DC pulse signal by the pulse generator 1, which are collected in real time by the first electromagnetic sensor 23, the first vibration sensor 24 and the first microphone 25 respectively. Furthermore, the first coordinate position and the timestamped first magnetic signal, first vibration signal and first sound signal are sent to mobile station 3 using the first wireless communication module 22.

[0075] Mobile measuring station 3, used to establish communication with reference measuring station 2 after each installation and fixation activity, utilizes a second satellite signal receiver 31 to obtain its second coordinate position after each installation and fixation activity, and timestamps the second magnetic signal, second vibration signal, and second sound signal generated when the power cable L is subjected to a high-voltage DC pulse signal by the pulse generator 1, which are respectively collected in real time by the second electromagnetic sensor 33, the second vibration sensor 34, and the second microphone 35. Furthermore, it uses a second wireless communication module 32 to receive the first coordinate position and the timestamped first magnetic signal, first vibration signal, and first sound signal sent by reference measuring station 2; and...

[0076] Based on the second coordinate position obtained after each installation and fixing, as well as the second magnetic signal, second vibration signal, and second sound signal with timestamps, and combined with the first coordinate position received from the reference measuring station 2 each time, as well as the first magnetic signal, first vibration signal, and first sound signal with timestamps, the data calculation module 36 determines the final location of the fault point in the power cable.

[0077] Understandably, a reference station is first randomly selected (as far away from the fault point as possible), and then reference measuring station 2 is placed at that reference station. Secondly, the position of the mobile measuring station 3 can be changed multiple times. Each time the position is changed, the mobile measuring station 3 first establishes an RTK system with the reference measuring station 2 using satellites, a first satellite signal receiver 21, and a second satellite signal receiver 22 to obtain high-precision position information in the local coordinate system. Then, it synchronously measures magnetic, vibration, and sound signals. Afterward, the mobile measuring station 3 analyzes the measurement results each time to estimate the final location of the fault point in the power cable. The number of times the mobile measuring station 3 establishes communication and performs measurements with the reference measuring station 2 can be determined by changing the position once and measuring multiple times at that location, or measuring only once, depending on the actual situation.

[0078] It should be noted that the electromagnetic sensors, vibration sensors, and microphones used in the reference measuring station 2 and the mobile measuring station 3 have the same structure, and the sampling frequency of the magnetic signal is 1kHz, the sampling frequency of the vibration signal is 2kHz, and the sampling frequency of the sound signal is 48kHz.

[0079] In this embodiment of the invention, after each communication measurement is completed, the data collected by the reference measurement station 2 is sent to the mobile measurement station 3, and the fault point is quickly estimated in the data calculation module 36 of the mobile measurement station 3.

[0080] like Figure 4 As shown, the data calculation module 36 includes a ranging start time determination submodule 361, a first flight time ranging submodule 362, a first intensity ranging submodule 363, a second flight time ranging submodule 364, a second intensity ranging submodule 365, a third flight time ranging submodule 366, a third intensity ranging submodule 367, and a fault point location submodule 368.

[0081] The ranging start time determination submodule 361 is used to determine the total number of times (i.e., the total number of measurements) that the mobile measuring station 3 establishes communication with the reference measuring station after being installed and fixed is k. Based on the second magnetic signal with timestamps collected by the mobile measuring station 3 from 1 to k times or the first magnetic signal with timestamps collected by the reference measuring station 2 from 1 to k times, the submodule extracts k start times corresponding to the synchronous measurement of magnetic signals, vibration signals and sound signals between the mobile measuring station 3 and the reference measuring station 2 from 1 to k times; where k is a positive integer greater than 1.

[0082] For example, firstly, for the k-th measurement, the first timestamped magnetic signal measured by reference station 2 is denoted as... And record the second magnetic signal measured by the three mobile measuring stations and marked with a timestamp as...

[0083] Secondly, the starting time of the simultaneous measurement of magnetic signal, vibration signal and sound signal in the kth measurement is obtained by using the threshold method formula (1).

[0084]

[0085] Among them, f e It is a fixed threshold parameter, usually taken as 0.9 according to experimental measurements.

[0086] Similarly, the corresponding starting time can be determined in the first to kth measurements.

[0087] Understandably, the second magnetic signal can also be used. The starting time is determined using the threshold method. The specific design should be flexible and tailored to the actual situation.

[0088] The first time-of-flight ranging submodule 362 is used to extract k end times corresponding to the second vibration signal measured by the mobile measuring station 3 in 1 to k times and the first vibration signal measured by the reference measuring station 2 in 1 to k times, based on the second vibration signal with timestamps collected by the mobile measuring station 3 in 1 to k times and the first vibration signal with timestamps collected by the reference measuring station 2 in 1 to k times. It also estimates k first propagation velocities of the vibration signal when it flies in the power cable L by combining the first coordinate position obtained by the reference measuring station 2 in 1 to k times and the second coordinate position obtained by the mobile measuring station 3 in 1 to k times. Furthermore, it calculates the k first flight ranging distances obtained by the mobile measuring station 3 and the reference measuring station 2 respectively in 1 to k times based on the flight time of the vibration signal, based on the time of flight of the ranging submodule 361 corresponding to the k times in 1 to k times.

[0089] For example, firstly, for the k-th measurement, the first vibration signal measured and timestamped at reference station 2 is recorded as... And the second vibration signal measured by the three mobile measuring stations and time-stamped is recorded as...

[0090] Secondly, using the threshold method formula (2), the first vibration signal measured by reference measuring station 2 in the kth measurement is obtained. The end time The second vibration signal was measured by mobile measuring station 3 in the kth measurement. The end time

[0091]

[0092] Among them, f vThe threshold parameter is fixed and is usually set to 0.3 based on experimental measurements.

[0093] Next, using formula (3), the first propagation velocity corresponding to the kth time when the vibration signal travels through the power cable L is estimated.

[0094]

[0095] in, This represents the first coordinate position obtained by reference station 2 in the kth measurement. This represents the second coordinate position obtained by the mobile surveying station 3 in the kth iteration;

[0096] Finally, the first flight ranging distance obtained by reference station 2 in the kth corresponding time is calculated using formula (4). The first flight ranging distance obtained by the mobile measuring station 3 in the kth corresponding time.

[0097]

[0098] Similarly, the first flight distance of the reference measuring station 2 and the mobile measuring station 3 when flying in the power cable L based on the vibration signal can be determined in the first to k measurements. It should be noted that since the reference measuring station 2 is in a fixed position, its first coordinate position obtained in each measurement will remain unchanged.

[0099] The first intensity ranging submodule 363 is used to fit the second vibration signal with timestamps collected by the mobile measuring station 3 in 1 to k times and the first vibration signal with timestamps collected by the reference measuring station 2 in 1 to k times using a preset first received signal intensity model to obtain k first intensity ranging distances obtained by the mobile measuring station 3 and the reference measuring station 2 respectively in 1 to k times based on the intensity of the vibration signal.

[0100] For example, the first vibration signal with a timestamp was measured based on reference measuring station 2. And three pairs of mobile measuring stations measured the second vibration signal with timestamps. Using formulas (5) and (6), the first intensity ranging distance obtained by the reference measuring station 2 in the kth time is calculated respectively. The first intensity ranging distance obtained by the mobile measuring station 3 in the kth corresponding time.

[0101]

[0102] Among them, g v(·) represents the preset first received signal strength model, and this received signal strength model is a function of signal strength and distance and is fitted by specific experiments.

[0103] Similarly, the first intensity ranging distance of the reference measuring station 2 and the mobile measuring station 3 based on the vibration signal intensity can be determined in the first to k measurements.

[0104] The second time-of-flight ranging submodule 364 is used to extract k end times corresponding to the second sound signal measured by the mobile measuring station 3 in 1 to k times and the first sound signal measured by the reference measuring station 2 in 1 to k times, based on the second sound signal with timestamps collected by the mobile measuring station 3 in 1 to k times and the first sound signal with timestamps collected by the reference measuring station 2 in 1 to k times. It also estimates k second propagation velocities of the sound signal when it flies in the power cable L by combining the first coordinate position obtained by the reference measuring station 2 in 1 to k times and the second coordinate position obtained by the mobile measuring station 3 in 1 to k times. Furthermore, it calculates k second flight ranging distances obtained by the mobile measuring station 3 and the reference measuring station 2 respectively in 1 to k times based on the flight time of the sound signal in the air, based on the k times collected by the ranging start time determination submodule 361 in 1 to k times.

[0105] For example, firstly, for the k-th measurement, the first time-stamped sound signal measured at reference station 2 is recorded as... And record the second sound signal measured by the three mobile measuring stations and marked with a timestamp as...

[0106] Secondly, using the threshold method formula (7), the first sound signal measured by reference measuring station 2 in the kth measurement is obtained. The end time The second sound signal was measured by mobile measuring station 3 in the kth measurement. The end time

[0107]

[0108] Among them, f s The threshold parameter is fixed and is usually set to 0.3 based on experimental measurements.

[0109] Next, using formula (8), the second propagation speed of the sound signal corresponding to the kth time when it travels through the air is estimated.

[0110]

[0111] Finally, the second flight ranging distance obtained by reference station 2 in the kth corresponding time is calculated using formula (9). and the second flight ranging distance obtained by mobile measuring station 3 in the kth corresponding time.

[0112]

[0113] Similarly, the second flight ranging distance of the reference measuring station 2 and the mobile measuring station 3 when flying in the air based on sound signals can be determined in the first to k measurements.

[0114] The second intensity ranging submodule 365 is used to fit the second time-stamped sound signals collected by the mobile measuring station 3 in 1 to k times and the first time-stamped sound signals collected by the reference measuring station 2 in 1 to k times using a preset second received signal intensity model to obtain k second intensity ranging distances obtained by the mobile measuring station 3 and the reference measuring station 2 respectively in 1 to k times based on the intensity of the sound signals in the air.

[0115] For example, the first time-stamped sound signal measured based on reference measurement station 2. And the mobile measuring station 3 pairs of timestamped second sound signals. Using formulas (10) and (11), the second intensity ranging distance obtained by the reference measuring station 2 in the kth time is calculated respectively. The second intensity ranging distance obtained by the mobile measuring station 3 in the kth corresponding measurement.

[0116]

[0117] Among them, g s,1 (·) represents a preset second received signal strength model, and this received signal strength model is a function of signal strength and distance and is fitted by specific experiments.

[0118] Similarly, the second intensity ranging distance based on the sound signal intensity can be determined for the reference measuring station 2 and the mobile measuring station 3 in the first to k measurements.

[0119] The third time-of-flight ranging submodule 366 is used to perform noise filtering on the second sound signal with timestamps collected by the mobile measuring station 3 in 1 to k times and the first sound signal with timestamps collected by the reference measuring station 2 in 1 to k times using a preset multipath cancellation technology. It further extracts the k end times of the second sound signal after filtering by the mobile measuring station 3 in 1 to k times and the k end times of the first sound signal after filtering by the reference measuring station 2 in 1 to k times. Combined with the first coordinate position obtained by the reference measuring station 2 in 1 to k times and the second coordinate position obtained by the mobile measuring station 3 in 1 to k times, it estimates the k third propagation velocities of the sound signal when it flies in the power cable L after filtering. Combined with the ranging start time, it determines the k start times extracted by the submodule 361 in 1 to k times and calculates the k third flight ranging distances obtained by the mobile measuring station 3 and the reference measuring station 2 respectively in 1 to k times based on the flight time of the sound signal in the power cable L.

[0120] For example, firstly, for the k-th measurement, multipath cancellation technology is used to measure the first time-stamped sound signal at reference station 2. The mobile measuring station 3 measured the second sound signal with a timestamp. The sound signal propagating through the air is eliminated to obtain the first sound signal measured by reference station 2 in the kth corresponding measurement. The sound signal obtained after noise filtering The second sound signal measured by mobile measuring station 3 in the kth corresponding measurement The sound signal obtained after noise filtering

[0121] Secondly, using the threshold method formula (12), the first sound signal measured by reference measuring station 2 in the kth measurement is obtained. The sound signal obtained after noise filtering The end time The second sound signal was measured by mobile measuring station 3 in the kth measurement. The sound signal obtained after noise filtering The end time

[0122]

[0123] Among them, f p The threshold parameter is fixed and is usually set to 0.3 based on experimental measurements.

[0124] Next, using formula (13), the third propagation speed of the sound signal corresponding to the kth propagation is estimated.

[0125]

[0126] Finally, using formula (14), the third flight ranging distance obtained by reference station 2 in the kth corresponding time is calculated. and the third flight ranging distance obtained by mobile measuring station 3 in the kth corresponding time.

[0127]

[0128] Similarly, the third flight ranging distance of the reference measuring station 2 and the mobile measuring station 3 when flying in the power cable L based on the sound signal can be determined in the first to k measurements.

[0129] The third intensity ranging submodule 367 is used to fit k third intensity ranging distances of the mobile measuring station and the reference measuring station in the power cable based on the second sound signal after 1 to k corresponding filters of the mobile measuring station 3 and the first sound signal after 1 to k corresponding filters of the reference measuring station, using a preset third received signal intensity model.

[0130] For example, based on the first sound signal measured by reference station 2 in the kth corresponding measurement. The sound signal obtained after noise filtering The second sound signal measured by mobile measuring station 3 in the kth corresponding measurement The sound signal obtained after noise filtering Using formulas (15) and (16), the third intensity distance of the reference measuring station 2 at the kth time is calculated respectively. The third intensity distance obtained by the mobile measuring station 3 in the kth corresponding measurement.

[0131]

[0132] Among them, g s,2 (·) represents the preset third received signal strength model, and this received signal strength model is a function of signal strength and distance and is fitted by specific experiments.

[0133] Similarly, the third intensity ranging distance of the reference measuring station 2 and the mobile measuring station 3 based on the sound signal in the power cable L can be determined in the first to k measurements.

[0134] The fault location submodule 368 is used to construct an objective function based on the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained by the mobile measuring station 3 in 1 to k corresponding times, and the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained by the reference measuring station 2 in 1 to k corresponding times, and in combination with six preset weighting weights. The particle swarm optimization algorithm and the Levenberg-Marquardt algorithm are used to find the optimal solution of the objective function, and the output of the optimal solution is the final location of the fault point in the power cable.

[0135] The objective function is expressed as shown in equation (17):

[0136]

[0137] in, denoted as , where is the estimated location of the fault point in power cable L; p is the quantity to be estimated for the location of the fault point; the superscript j represents the number of measurements, and j = 1, 2, ..., k; the subscript r represents reference station 2; the subscript m represents mobile station 3; d represents the distance; the subscript i represents the type of measurement distance; w i Represents the i-th weighted weight, and

[0138] At this point, the inventors discovered that the method for estimating the location using this objective function can be transformed into a nonlinear least squares problem. Since the measurement information increases with the number of measurements, it is necessary to use intelligent search algorithms, Newton's descent method, or the Levenberg-Marquardt algorithm to solve it. Therefore, particle swarm optimization and the Levenberg-Marquardt algorithm are used to find the optimal solution for the objective function, and the output of the optimal solution is the final location of the fault point in the power cable.

[0139] It should be noted that using intelligent search algorithms, Newton's descent method, or Levenberg-Marquardt algorithm to solve nonlinear least squares problems are common techniques in this field, and will not be elaborated upon here.

[0140] like Figure 5 As shown, the application scenario of a power cable fault trench location system according to an embodiment of the present invention will be further explained as follows:

[0141] exist Figure 5In this method, to locate cable faults within urban cable trenches, a total of one reference measuring station, one mobile measuring station, and one pulse generator are used. The pulse generator delivers high-voltage pulse signals to the faulty cable at fixed intervals, triggering the fault point to emit an audible signal. The reference measuring station is positioned 20-30 meters away from the fault point, and its coordinates do not require manual calibration. The mobile measuring station is carried by the operator. After measuring 3-5 times at a single location, it is moved a certain distance towards the fault point. After 2-3 adjustments, the precise location of the fault point can be obtained.

[0142] During each measurement, the reference station and the mobile station synchronize their clocks via the BeiDou satellite system. In the k-th measurement, the positions of the reference station and the mobile station are obtained as follows: and

[0143] The pulse generator produces a high-voltage pulse signal every 30 seconds, exciting the fault point to emit an acoustic signal. The signal is then collected by electromagnetic sensors on the reference and mobile measurement stations, vibration sensors on vibration, and microphones on acoustic. The sampling frequency for the magnetic signal is 1 kHz, for the vibration signal it is 2 kHz, and for the acoustic signal it is 48 kHz.

[0144] The reference measurement station encapsulates the first coordinate position of BeiDou positioning together with the first magnetic signal, the first vibration signal and the first sound signal with a timestamp into a data packet, and then sends it to the mobile measurement station through the first wireless communication module.

[0145] The mobile measuring station, based on the second coordinate position of BeiDou positioning, and based on its own timestamped second magnetic signal, second vibration signal, and second sound signal, combined with the first coordinate position of the reference measuring station and the timestamped first magnetic signal, first vibration signal, and first sound signal, estimates various types of distances according to the above formulas (1) to (16). Furthermore, the Particle Swarm Optimization (PSO) algorithm is used to estimate the location of the fault point based on formula (17), and then this is used as the initial value for accurate solution based on the LM algorithm to obtain the coordinates of the fault point. The weights are set as w = [0.2, 0.1, 0.3, 0.1, 0.2, 0.1].

[0146] like Figure 6 As shown, this is an embodiment of the present invention providing a method for locating power cable faults in a trench, which is implemented on a power cable fault trench location system in this embodiment of the present invention. The method includes the following steps:

[0147] Step S1: The pulse generator periodically applies a high-voltage DC pulse signal to the power cable so that when there is a fault point in the power cable, it can excite the fault point to emit a sound signal.

[0148] Step S2: The reference measuring station obtains its own first coordinate position, and timestamps the first magnetic signal, first vibration signal and first sound signal generated when the power cable is subjected to a high voltage DC pulse signal by the pulse generator. Furthermore, the obtained first coordinate position and the timestamped first magnetic signal, first vibration signal and first sound signal are sent to the mobile measuring station.

[0149] Step S3: When the mobile measuring station establishes communication with the reference measuring station after each installation and fixation, it obtains its second coordinate position after each installation and fixation, and timestamps the second magnetic signal, second vibration signal, and second sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator. Combined with the first coordinate position received from the reference measuring station each time, and the timestamped first magnetic signal, first vibration signal, and first sound signal, the final location of the fault point in the power cable is determined.

[0150] The specific process is as follows: In step S1, the pulse generator periodically (e.g., once every 30 seconds) applies a high-voltage DC pulse signal to the power cable so that when there is a fault point in the power cable, the fault point can be excited to emit a sound signal.

[0151] In step S2, the reference measuring station obtains its first coordinate position based on a satellite (such as the BeiDou satellite) using a first satellite signal receiver, and timestamps the first magnetic signal, first vibration signal, and first sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator, which are collected in real time by the first electromagnetic sensor, the first vibration sensor, and the first microphone, respectively. Furthermore, the first wireless communication module transmits the obtained first coordinate position and the timestamped first magnetic signal, first vibration signal, and first sound signal to the mobile measuring station.

[0152] In step S3, firstly, the total number of times the mobile measuring station establishes communication with the reference measuring station after its mobile installation and fixation is determined to be k. Based on the second magnetic signal with timestamps collected by the mobile measuring station from 1 to k times or the first magnetic signal with timestamps collected by the reference measuring station from 1 to k times, k starting times corresponding to the synchronous measurement of magnetic signals, vibration signals and sound signals between the mobile measuring station and the reference measuring station are extracted from 1 to k times; where k is a positive integer greater than 1.

[0153] Secondly, based on the second vibration signal with timestamps collected by the mobile measuring station from 1 to k times and the first vibration signal with timestamps collected by the reference measuring station from 1 to k times, the k end times of the second vibration signal measured by the mobile measuring station from 1 to k times and the k end times of the first vibration signal measured by the reference measuring station from 1 to k times are extracted. Combined with the first coordinate position obtained by the reference measuring station from 1 to k times and the second coordinate position obtained by the mobile measuring station from 1 to k times, the k first propagation velocities of the vibration signal when flying in the power cable are estimated. Furthermore, combined with the k start times extracted from 1 to k times, the k first flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively in the flight time based on the vibration signal from 1 to k times are calculated.

[0154] Next, based on the second vibration signal with timestamps collected by the mobile measuring station from 1 to k times and the first vibration signal with timestamps collected by the reference measuring station from 1 to k times, the k first intensity ranging distances obtained by the mobile measuring station and the reference measuring station respectively in 1 to k times based on the intensity of the vibration signal are fitted using a preset first received signal intensity model.

[0155] Next, based on the second sound signal with timestamps collected by the mobile measuring station from 1 to k times and the first sound signal with timestamps collected by the reference measuring station from 1 to k times, the k end times of the second sound signal measured by the mobile measuring station from 1 to k times and the k end times of the first sound signal measured by the reference measuring station from 1 to k times are extracted. Combined with the first coordinate position obtained by the reference measuring station from 1 to k times and the second coordinate position obtained by the mobile measuring station from 1 to k times, the k second propagation speeds of the sound signal when it flies in the power cable are estimated. Furthermore, combined with the k start times extracted from 1 to k times, the k second flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively from 1 to k times based on the flight time of the sound signal in the air are calculated.

[0156] Next, based on the second time-stamped sound signals collected by the mobile measuring station from 1 to k times and the first time-stamped sound signals collected by the reference measuring station from 1 to k times, the k second intensity ranging distances obtained by the mobile measuring station and the reference measuring station from 1 to k times based on the intensity of the sound signals in the air are fitted using a preset second received signal intensity model.

[0157] Next, using a preset multipath cancellation technique, noise filtering is applied to the second sound signal with timestamps collected by the mobile measuring station from times 1 to k and the first sound signal with timestamps collected by the reference measuring station from times 1 to k. Furthermore, the k end times of the filtered second sound signal collected by the mobile measuring station from times 1 to k and the k end times of the filtered first sound signal collected by the reference measuring station from times 1 to k are extracted. Combined with the first coordinate position obtained by the reference measuring station from times 1 to k and the second coordinate position obtained by the mobile measuring station from times 1 to k, the k third propagation velocities of the sound signal during flight in the power cable after filtering are estimated. Finally, combined with the k start times extracted from times 1 to k, the k third flight ranging distances obtained by the mobile measuring station and the reference measuring station respectively during the flight time of the sound signal in the power cable from times 1 to k are calculated.

[0158] Next, based on the second sound signal filtered by the mobile measuring station from 1 to k times and the first sound signal filtered by the reference measuring station from 1 to k times, the k third intensity ranging distances of the mobile measuring station and the reference measuring station in the power cable from 1 to k times are obtained by fitting using a preset third received signal strength model.

[0159] Finally, based on the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained from the mobile measuring station for 1 to k corresponding times, and the k first flight ranging distances, k second flight ranging distances, k third flight ranging distances, k first intensity ranging distances, k second intensity ranging distances, and k third intensity ranging distances obtained from the reference measuring station for 1 to k corresponding times, and combined with the preset six weighted weights, an objective function is constructed. The particle swarm optimization algorithm and the Levenberg-Marquardt algorithm are used to find the optimal solution of the objective function, and the output of the optimal solution is the final location of the fault point in the power cable.

[0160] Implementing the embodiments of the present invention has the following beneficial effects:

[0161] 1. This invention can quickly locate power cable faults based on satellite, vibration signals, magnetic signals and sound signals, thereby enabling rapid and accurate location of power cable fault points in the complex environment of cable trenches in cities. It provides tools and means for the safe operation and risk management of power cables. Therefore, it has advantages such as good stability, high positioning accuracy and fast positioning speed, and can reduce the need for manpower to investigate and dig trenches.

[0162] 2. This invention utilizes satellites to form an RTK system with a reference measurement station and a mobile measurement station, thereby obtaining high-precision position information. Based on the coordinate information of the reference measurement station and the mobile measurement station, the propagation speed of vibration and sound signals in power cables and the propagation speed of sound signals in the atmosphere are calibrated in real time, thereby improving the accuracy of distance estimation.

[0163] 3. This invention transforms the fault location estimation problem in the objective function into a nonlinear weighted least squares problem, and then uses a heuristic algorithm to solve it, thereby gradually improving the fault location accuracy.

[0164] It is worth noting that the various system modules included in the above system embodiments are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional module are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0165] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, optical disk, etc.

[0166] 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, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power cable fault location system in a trench, characterized in that, It includes a pulse generator, a reference measuring station, and a mobile measuring station; among which, The pulse generator is applied to the power cable within the cable trench; The reference measurement station is fixedly installed in the cable trench; the reference measurement station is equipped with a first satellite signal receiver, a first wireless communication module, and a first electromagnetic sensor, a first vibration sensor, and a first microphone, all of which are connected to the power cable. The mobile measuring station is installed in the cable trench, and after each installation, it maintains a certain distance from the reference measuring station and establishes communication with the reference measuring station. The mobile measuring station is equipped with a second satellite signal receiver, a second wireless communication module, a data calculation module, and a second electromagnetic sensor, a second vibration sensor, and a second microphone, all connected to the power cable. The second wireless communication module of the mobile measuring station and the first wireless communication module of the reference measuring station achieve communication interconnection and establishment. The pulse generator is used to periodically apply a high-voltage DC pulse signal to the power cable so that when there is a fault point in the power cable, it can excite the fault point to emit a sound signal. The reference measurement station is used to obtain its own first coordinate position based on the satellite using the first satellite signal receiver, and to timestamp the first magnetic signal, first vibration signal and first sound signal generated when the power cable is subjected to a high voltage DC pulse signal by the pulse generator, which are respectively collected in real time by the first electromagnetic sensor, the first vibration sensor and the first microphone. Furthermore, the first wireless communication module is used to send the obtained first coordinate position and the timestamped first magnetic signal, first vibration signal and first sound signal to the mobile measurement station. The mobile measuring station, when establishing communication with the reference measuring station after each installation and fixation activity, uses the second satellite signal receiver to obtain its second coordinate position after each installation and fixation activity, based on the satellite. It also timestamps the second magnetic signal, second vibration signal, and second sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator, which are respectively collected in real time by the second electromagnetic sensor, the second vibration sensor, and the second microphone. Furthermore, it uses the second wireless communication module to receive the first coordinate position and the timestamped first magnetic signal, first vibration signal, and first sound signal sent by the reference measuring station. Based on the second coordinate position obtained after each installation and fixing, as well as the second magnetic signal, second vibration signal, and second sound signal with timestamps, and combined with the first coordinate position, first magnetic signal, first vibration signal, and first sound signal received from the reference measuring station each time, the final location of the fault point in the power cable is determined using the data calculation module.

2. The power cable fault trench location system as described in claim 1, characterized in that, The mobile measuring station and the reference measuring station form an RTK system using the satellite, the first satellite signal receiver, and the second satellite signal receiver.

3. The power cable fault trench location system as described in claim 2, characterized in that, The data calculation module includes: The ranging start time determination submodule is used to determine the total number of times the mobile measuring station establishes communication with the reference measuring station after its mobile installation and fixation. and based on the mobile measuring station The second magnetic signal collected and time-stamped, or the reference measuring station The first time-stamped magnetic signal collected is used to extract the corresponding magnetic signal, vibration signal, and sound signal measured synchronously between the mobile measuring station and the reference measuring station. Second There are several starting times; among them, It is a positive integer greater than 1; The first time-of-flight ranging submodule is used to measure distances based on the mobile measuring station. The second vibration signal, time-stamped and collected, and the reference measuring station The first vibration signal, timestamped and collected, was used to extract the data from the mobile measuring station. The second vibration signal was measured in the corresponding sequence. The end time and the reference measuring station mentioned above The first vibration signal was measured in the corresponding sequence. At the end time, and in conjunction with the reference measuring station The first coordinate position obtained and the mobile measuring station The second coordinate position obtained is used to estimate the vibration signal's trajectory in the power cable. The first propagation speed, and further combined with the ranging start time, determines the corresponding submodule. The extracted At each initial moment, the positions of the mobile measuring station and the reference measuring station are calculated. The flight time obtained based on vibration signals The first flight ranging distance; The first intensity ranging submodule is used to measure distances based on the mobile measuring station. The second vibration signal, time-stamped and collected, and the reference measuring station The first vibration signal, timestamped and collected, is used to fit the pre-set first received signal intensity model to obtain the respective vibration values ​​of the mobile measuring station and the reference measuring station. This is obtained based on the intensity of the vibration signal. The first intensity ranging distance; The second time-of-flight ranging submodule is used to measure distances based on the mobile measuring station. The second time-stamped audio signal collected and the reference measuring station The first time-stamped audio signal collected was used to extract the information from the mobile measuring station. The second sound signal was measured in the corresponding sub-measurement. The end time and the reference measuring station mentioned above The first sound signal was measured in the corresponding sequence. At the end time, and in conjunction with the reference measuring station The first coordinate position obtained and the mobile measuring station The second coordinate position obtained is used to estimate the flight time of the sound signal in the power cable. The second propagation speed, and further combined with the ranging start time, determines the corresponding submodule. The extracted At each initial moment, the positions of the mobile measuring station and the reference measuring station are calculated. This is based on the flight time of the sound signal in the air. The second flight ranging distance; The second intensity ranging submodule is used to measure distances based on the mobile measuring station. The second time-stamped audio signal collected and the reference measuring station The first time-stamped audio signal collected is used to fit the signal strength of the mobile measuring station and the reference measuring station using a preset second received signal strength model. This is based on the intensity of the sound signal in the air. The second intensity ranging distance; The third time-of-flight ranging submodule is used to perform multipath elimination on the mobile measuring station using a preset multipath elimination technique. The second time-stamped audio signal collected and the reference measuring station The first time-stamped audio signal collected was then subjected to noise filtering to further extract the information from the mobile measuring station. The second audio signal after corresponding filtering The end time and the reference measuring station mentioned above This corresponds to the first audio signal after filtering. At the end time, and in conjunction with the reference measuring station The first coordinate position obtained and the mobile measuring station The second coordinate position obtained is used to estimate the flight time of the filtered sound signal in the power cable. The third propagation speed, combined with the ranging start time, determines the corresponding submodule. The extracted At each initial moment, the positions of the mobile measuring station and the reference measuring station are calculated. This is based on the flight time of the sound signal in the power cable. The third flight ranging distance; The third intensity ranging submodule is used to measure distances based on the mobile measuring station. The second sound signal after filtering and the reference measuring station After filtering, the first sound signal is used to fit the signal strength of the mobile measuring station and the reference measuring station using a preset third received signal strength model. This is based on the intensity of the sound signal in the power cable. The third intensity ranging distance; The fault location submodule is used to locate the fault point based on the information obtained from the mobile measuring station. The result of the next correspondence First flight ranging distance, The second flight ranging distance, The third flight ranging distance, The first intensity ranging distance, The second intensity ranging distance and The third intensity ranging distance, and the reference measuring station The result of the next correspondence First flight ranging distance, The second flight ranging distance, The third flight ranging distance, The first intensity ranging distance, The second intensity ranging distance and A third intensity ranging distance is used, and six preset weights are combined to construct an objective function. The particle swarm optimization algorithm and the Levenberg-Marquardt algorithm are used to find the optimal solution of the objective function. The output of the optimal solution is the final location of the fault point in the power cable.

4. The power cable fault trench location system as described in claim 3, characterized in that, The objective function is: ;in, The estimated location of the fault point in the power cable; The quantity to be estimated is the location of the fault; superscript Represents the number of measurements, and ; Subscript Represents the reference measurement station; subscript Represents the mobile measuring station; Represents distance; subscript This represents the type of distance measurement; Representing the Each weighted weight, and ; ; The reference measuring station represents the first The first coordinate position obtained; The mobile measuring station represents the first The second coordinate position obtained this time; The reference measuring station represents the first The first flight ranging distance obtained from the corresponding sequence. The mobile measuring station represents the first The first flight ranging distance obtained from the corresponding sequence. The reference measuring station represents the first The first intensity ranging distance obtained from the corresponding step The mobile measuring station represents the first The first intensity ranging distance obtained from the corresponding step The reference measuring station represents the first The second flight ranging distance obtained from the corresponding sequence. The mobile measuring station represents the first The second flight ranging distance obtained from the corresponding sequence. The reference measuring station represents the first The second intensity ranging distance obtained from the corresponding step The mobile measuring station represents the first The second intensity ranging distance obtained from the corresponding step The reference measuring station represents the first The third flight ranging distance obtained from the corresponding sequence The mobile measuring station represents the first The third flight ranging distance obtained from the corresponding sequence; The reference measuring station represents the first The third intensity ranging distance obtained from the corresponding step The mobile measuring station represents the first The third intensity ranging distance obtained from the corresponding step.

5. The power cable fault trench location system as described in claim 4, characterized in that, Through formula The reference measuring station was calculated to be at the 1st The first flight ranging distance obtained from the corresponding step and the mobile measuring station at the first The first flight ranging distance obtained from the corresponding step ;in, The vibration signal corresponds to the first one when it travels in the power cable. The first propagation speed, and ; By using the threshold method, we obtain ; The reference measuring station represents the first The first vibration signal corresponding to the measurement. The reference measuring station represents the first The first vibration signal was measured in the corresponding measurement. At the end of the day, The mobile measuring station represents the first The second vibration signal was measured in the corresponding sequence. The mobile measuring station represents the first The second vibration signal was measured in the corresponding measurement. At the end of the day, A fixed threshold parameter; By using the threshold method, we obtain ; The reference measuring station represents the first The first magnetic signal measured in this correspondence. Representing the reference measuring station and the mobile measuring station at the first The start time of the next synchronous measurement of magnetic, vibration, and sound signals. It is a fixed threshold parameter.

6. The power cable fault trench location system as described in claim 5, characterized in that, Through formula The reference measuring station was calculated to be at the 1st The second flight ranging distance obtained from the corresponding step and the mobile measuring station at the first The second flight ranging distance obtained from the corresponding step ;in, This represents the sound signal corresponding to the number when it travels through the air. The second propagation speed, and ; By using the threshold method, we obtain ; The reference measuring station represents the first The first sound signal was measured in this corresponding sequence. The reference measuring station represents the first The first sound signal was measured in the corresponding measurement. At the end of the day, The mobile measuring station represents the first The second sound signal was measured in this correspondence. The mobile measuring station represents the first The second sound signal was measured in the corresponding measurement. At the end of the day, It is a fixed threshold parameter.

7. The power cable fault trench location system as described in claim 6, characterized in that, Through formula The reference measuring station was calculated to be at the 1st The third flight ranging distance obtained from the next correspondence and the mobile measuring station at the first The third flight ranging distance obtained from the next correspondence ;in, The sound signal corresponds to the first [unclear] when it travels in the power cable. The third propagation speed, and ; By using the threshold method, we obtain ; The reference measuring station represents the first The first sound signal measured in this correspondence The sound signal obtained after noise filtering The reference measuring station represents the first The first audio signal is filtered accordingly. The obtained sound signal At the end of the day, The mobile measuring station represents the first The second sound signal measured in the corresponding sequence The sound signal obtained after noise filtering The mobile measuring station represents the first This corresponds to the second sound signal. The obtained sound signal At the end of the day, It is a fixed threshold parameter.

8. The power cable fault trench location system as described in claim 7, characterized in that, Through formula Calculate the reference measurement station at the th The first intensity ranging distance obtained from the corresponding step ; Through formula The calculation yields the mobile measuring station at the [number]th [location]. The first intensity ranging distance obtained from the corresponding step ; Through formula Calculate the reference measurement station at the th The second intensity ranging distance obtained from this correspondence ; Through formula The calculation yields the mobile measuring station at the [number]th [location]. The second intensity ranging distance obtained from this correspondence ; Through formula Calculate the reference measurement station at the th The third intensity ranging distance obtained from the next corresponding step ; Through formula The calculation yields the mobile measuring station at the [number]th [location]. The third intensity ranging distance obtained from the next corresponding step ; in, This represents the preset first received signal strength model. This represents a preset second received signal strength model. This represents the preset third received signal strength model, and all three received signal strength models are functions of signal strength and distance, and are fitted by specific experiments.

9. A method for locating power cable faults within a trench, characterized in that, It is implemented in the power cable fault trench location system as described in claim 8, and the method includes the following steps: The pulse generator periodically applies a high-voltage DC pulse signal to the power cable so that when there is a fault point in the power cable, it can excite the fault point to emit a sound signal. The reference measuring station obtains its own first coordinate position and timestamps the first magnetic signal, first vibration signal and first sound signal generated when the power cable is subjected to a high voltage DC pulse signal by the pulse generator. Furthermore, the obtained first coordinate position and the timestamped first magnetic signal, first vibration signal and first sound signal are sent to the mobile measuring station. When the mobile measuring station establishes communication with the reference measuring station after each installation and fixation, it obtains its second coordinate position after each installation and fixation, and timestamps the second magnetic signal, second vibration signal, and second sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator. Combined with the first coordinate position received from the reference measuring station each time, as well as the timestamped first magnetic signal, first vibration signal, and first sound signal, the final location of the fault point in the power cable is determined.

10. The method for locating power cable faults in a trench as described in claim 9, characterized in that, When the mobile measuring station establishes communication with the reference measuring station after each installation and fixation, it obtains its second coordinate position after each installation and fixation, and timestamps the second magnetic signal, second vibration signal, and second sound signal generated when the power cable is subjected to a high-voltage DC pulse signal by the pulse generator. Combining this with the first coordinate position received from the reference measuring station each time, along with the timestamped first magnetic signal, first vibration signal, and first sound signal, the specific steps for determining the final location of the fault point in the power cable include: The total number of times the mobile measuring station established communication with the reference measuring station after its mobile installation and fixation was determined to be: and based on the mobile measuring station The second magnetic signal collected and time-stamped, or the reference measuring station The first time-stamped magnetic signal collected is used to extract the corresponding magnetic signal, vibration signal, and sound signal measured synchronously between the mobile measuring station and the reference measuring station. Second There are several starting times; among them, It is a positive integer greater than 1; Based on the mobile measuring station The second vibration signal, time-stamped and collected, and the reference measuring station The first vibration signal, timestamped and collected, was used to extract the data from the mobile measuring station. The second vibration signal was measured in the corresponding sequence. The end time and the reference measuring station mentioned above The first vibration signal was measured in the corresponding sequence. At the end time, and in conjunction with the reference measuring station The first coordinate position obtained and the mobile measuring station The second coordinate position obtained is used to estimate the vibration signal's trajectory in the power cable. The first propagation speed, and further combined with the corresponding The extracted At each initial moment, the positions of the mobile measuring station and the reference measuring station are calculated. The flight time obtained based on vibration signals The first flight ranging distance; Based on the mobile measuring station The second vibration signal, time-stamped and collected, and the reference measuring station The first vibration signal, timestamped and collected, is used to fit the pre-set first received signal intensity model to obtain the respective vibration values ​​of the mobile measuring station and the reference measuring station. This is obtained based on the intensity of the vibration signal. The first intensity ranging distance; Based on the mobile measuring station The second time-stamped audio signal collected and the reference measuring station The first time-stamped audio signal collected was used to extract the information from the mobile measuring station. The second sound signal was measured in the corresponding sub-measurement. The end time and the reference measuring station mentioned above The first sound signal was measured in the corresponding sequence. At the end time, and in conjunction with the reference measuring station The first coordinate position obtained and the mobile measuring station The second coordinate position obtained is used to estimate the flight time of the sound signal in the power cable. A second propagation speed, and further corresponding to The extracted At each initial moment, the positions of the mobile measuring station and the reference measuring station are calculated. This is based on the flight time of the sound signal in the air. The second flight ranging distance; Based on the mobile measuring station The second time-stamped audio signal collected and the reference measuring station The first time-stamped audio signal collected is used to fit the signal strength of the mobile measuring station and the reference measuring station using a preset second received signal strength model. This is based on the intensity of the sound signal in the air. The second intensity ranging distance; Using a pre-defined multipath elimination technique, the mobile measuring station is... The second time-stamped audio signal collected and the reference measuring station The first time-stamped audio signal collected was then subjected to noise filtering to further extract the information from the mobile measuring station. The second audio signal after corresponding filtering The end time and the reference measuring station mentioned above This corresponds to the first audio signal after filtering. At the end time, and in conjunction with the reference measuring station The first coordinate position obtained and the mobile measuring station The second coordinate position obtained is used to estimate the flight time of the filtered sound signal in the power cable. A third propagation speed, and combined with the corresponding The extracted At each initial moment, the positions of the mobile measuring station and the reference measuring station are calculated. This is based on the flight time of the sound signal in the power cable. The third flight ranging distance; Based on the mobile measuring station The second sound signal after filtering and the reference measuring station After filtering, the first sound signal is used to fit the signal strength of the mobile measuring station and the reference measuring station using a preset third received signal strength model. This is based on the intensity of the sound signal in the power cable. The third intensity ranging distance; According to the mobile measuring station The result of the next correspondence First flight ranging distance, The second flight ranging distance, The third flight ranging distance, The first intensity ranging distance, The second intensity ranging distance and The third intensity ranging distance, and the reference measuring station The result of the next correspondence First flight ranging distance, The second flight ranging distance, The third flight ranging distance, The first intensity ranging distance, The second intensity ranging distance and A third intensity ranging distance is used, and six preset weights are combined to construct an objective function. The particle swarm optimization algorithm and the Levenberg-Marquardt algorithm are used to find the optimal solution of the objective function. The output of the optimal solution is the final location of the fault point in the power cable.

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