A method and device for locating traveling wave faults in distribution network

Abstract

The present invention relates to a method and device for locating a traveling wave fault in a distribution network, the method comprising: extracting the transient characteristics of a distribution network voltage signal within an analysis time window and discretizing the transient characteristics of the distribution network voltage signal within the analysis time window; determining the probability of a fault occurring in each section of the distribution network according to the discretized transient characteristics; determining the distribution network fault section according to the probability of a fault occurring in each section of the distribution network; wherein the transient characteristics of the distribution network voltage signal include: the amplitude of the detail coefficient of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal, and the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal. The technical solution provided by the present invention does not require high-precision timing, has high positioning reliability, and is less affected by the type of fault.

Description

Technical Field

[0001] The present invention relates to the field of power system automation, and in particular to a method and device for locating traveling wave faults in a distribution network. Background Art

[0002] Medium and low voltage distribution networks generally use small current grounding systems. Small current grounding systems have high power supply reliability and can continue to operate for a period of time after a fault. However, the fault current in small current grounding systems is small, making fault location difficult.

[0003] At present, the research in the field of distribution network fault location is mainly based on steady-state quantities, using data collected by fault indicators or distribution network automation terminal equipment to complete the fault section location. Researchers have carried out a lot of research in this field and proposed fault location methods such as BP neural network, LVQ neural network, and extreme learning machine, but these methods still have many problems in application: First, the above positioning methods all require a large number of training samples, but it is difficult to provide a large amount of historical data as training samples in actual power grid fault location, and the algorithm is not intuitive, and it is difficult to establish a direct mapping; second, it is greatly affected by the fault type. In the case of a single-phase grounding fault, the fault current amplitude is low, which directly affects the positioning reliability, and single-phase grounding faults account for more than 70% of the total distribution network faults.

[0004] Compared with steady-state quantity positioning, transient quantity positioning is not affected by factors such as system grounding mode and power flow distribution. Therefore, transient quantity positioning is the best solution to solve single-phase grounding faults. At present, distribution network transient quantity monitoring equipment is divided into two categories: the first category is transient fault indicators and distribution network feeder terminals. The sampling rate of this type of equipment is generally below 10kHz. The fault section is mainly determined based on the difference in transient energy. However, due to the low sampling rate, it is greatly affected by the fault type and branch lines. The second category is the distribution network traveling wave fault positioning device. This type of equipment has a higher sampling rate, generally exceeding 500kHz. Compared with the first type of distribution network transient quantity monitoring equipment, it can more effectively extract transient information. In terms of positioning methods, this type of equipment continues the idea of ​​high-voltage line traveling wave fault ranging, and uses the time difference of the traveling wave reaching each monitoring point to complete the fault positioning. However, this type of method has the following problems in previous studies: First, high-precision timing is required based on the time difference, but due to the limitations of device cost and on-site installation conditions, the timing accuracy and reliability are difficult to guarantee; second, the distribution network line structure is relatively complex, and generally there are multiple branch lines, but multiple branch lines will cause traveling wave signal attenuation and waveform distortion, affecting the fault positioning accuracy; third, there are many interferences in the distribution network, and the static reactive power compensation device and the start-up of large-capacity motors may cause interference. These interferences affect the identification of transient traveling waves on the one hand, and on the other hand, they cause the device to start frequently, increasing communication pressure. Therefore, it is necessary to invent a new distribution network traveling wave fault positioning method to solve the above problems. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a distribution network traveling wave fault location method which does not require high-precision timing, is not affected by the complex structure of the distribution network line, can perform reliable positioning, and is less affected by the fault type.

[0006] The purpose of the present invention is achieved by adopting the following technical solutions:

[0007] A method for locating traveling wave faults in a distribution network, the improvement of which lies in that the method comprises:

[0008] Extracting transient characteristics of the distribution network voltage signal within the analysis time window and discretizing the transient characteristics of the distribution network voltage signal within the analysis time window;

[0009] Determine the probability of failure in each section of the distribution network based on the discretized transient characteristics;

[0010] Determining a fault section of the distribution network according to the probability of failure of each section in the distribution network;

[0011] Among them, the transient characteristics of the distribution network voltage signal include: the detail coefficient amplitude of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal and the ratio of the high frequency component to the low frequency component in the first half wave of the distribution network voltage signal.

[0012] Preferably, the process of obtaining the analysis time window includes:

[0013] The voltage signal of the distribution network is decomposed into detail coefficients and approximate coefficients by using wavelet transform;

[0014] Extracting a modulus maximum sequence of the detail coefficients;

[0015] Based on the modulus maximum sequence of the detail coefficients, the initial time t at which the voltage signal of the distribution network fails is determined using the modulus maximum method. 0 , and the initial time t 0 As the initial moment of the analysis window;

[0016] The initial time t 0 The first modulus maximum in the modulus maximum sequence whose modulus maximum is greater than zero and less than the threshold ζ corresponds to time t e As the end time of the analysis window.

[0017] Furthermore, the process of acquiring the transient energy of the distribution network voltage signal includes:

[0018] Reconstructing the high frequency component of the power distribution network voltage signal using the detail coefficients;

[0019] The transient energy S of the distribution network voltage signal is determined by the following formula:

[0020]

[0021] Among them, U hfi To analyze the high-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t 0 ,t e ], n is the length of the analysis window, n = t e -t 0 , t e is the end time of the analysis window, t 0 is the initial time of the analysis window.

[0022] Furthermore, the process of obtaining the ratio of the high frequency part to the low frequency part in the first half wave of the distribution network voltage signal includes:

[0023] Reconstructing the high-frequency component of the distribution network voltage signal using the detail coefficients, and reconstructing the low-frequency component of the distribution network voltage signal using the approximate coefficients;

[0024] The ratio P of the high-frequency part to the low-frequency part in the first half-wave of the distribution network voltage signal is determined by the following formula:

[0025]

[0026] Among them, U hfi is the high-frequency component of the distribution network voltage signal at the i-th moment in the analysis time window, U lfi To analyze the low-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t 0 ,t e ],t e is the end time of the analysis window, t 0 is the initial time of the analysis window.

[0027] Preferably, the discretizing the transient characteristics of the distribution network voltage signal includes:

[0028] The amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to their absolute values, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0;

[0029] The transient energies of the distribution network voltage signals in the transient characteristics of the distribution network voltage signals monitored by all monitoring terminals in the distribution network are sorted in descending order according to the size of their absolute values, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the remaining monitoring terminals are defined as 0;

[0030] The ratios of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to the absolute value, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0.

[0031] Preferably, determining the probability of failure of each section in the distribution network according to the discretized transient characteristics includes:

[0032] The probability P of failure in section m is determined as follows: m :

[0033]

[0034] Among them, d m is the length of the line in section m, D is the total length of the distribution network line, P j is the probability of failure in section m corresponding to the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, j∈[1,s], s is the total number of monitoring terminals adjacent to section m.

[0035] Furthermore, the probability P of a fault in the segment m corresponding to the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is j The acquisition process includes:

[0036] The probability P of the fault in the segment m corresponding to the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is determined as follows: j :

[0037]

[0038] Among them, P j1 is the probability of fault in section m corresponding to the amplitude of the detail coefficient at the initial moment of fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, is the probability of failure in section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, It is the probability of fault in section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the discrete distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to section m.

[0039] Furthermore, when the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault in the section m corresponding to the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0;

[0040] When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy amplitude of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault of the section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0;

[0041] When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 4, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 3, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 2, the probability of fault in the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 1, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the section m fault corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0;

[0042] Where s is the total number of monitoring terminals adjacent to segment m.

[0043] Preferably, determining the faulty section of the distribution network according to the probability of faults occurring in each section of the distribution network comprises:

[0044] The section with the highest probability of failure is obtained, and the section with the highest probability of failure is the distribution network failure section.

[0045] Preferably, after determining the faulty section of the distribution network according to the probability of failure of each section in the distribution network, the method further comprises:

[0046] A single-ended traveling wave method is used to determine the fault point of the distribution network in the fault section of the distribution network.

[0047] A distribution network traveling wave fault locating device, the improvement of which is that the device comprises:

[0048] A data processing unit, used to extract the transient characteristics of the distribution network voltage signal within the analysis time window and discretize the transient characteristics of the distribution network voltage signal within the analysis time window;

[0049] A first determination unit is used to determine the probability of failure of each section in the distribution network according to the discretized transient characteristics;

[0050] A second determining unit, configured to determine a faulty section of the distribution network according to a probability of a fault occurring in each section of the distribution network;

[0051] Among them, the transient characteristics of the distribution network voltage signal include: the detail coefficient amplitude of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal and the ratio of the high frequency component to the low frequency component in the first half wave of the distribution network voltage signal.

[0052] Compared with the closest prior art, the present invention has the following beneficial effects:

[0053] The technical solution provided by the present invention extracts the transient characteristics of the distribution network voltage signal within the analysis time window and discretizes the transient characteristics of the distribution network voltage signal within the analysis time window; determines the probability of failure in each section of the distribution network according to the discretized transient characteristics; determines the fault section of the distribution network according to the probability of failure in each section of the distribution network; wherein the transient characteristics of the distribution network voltage signal include: the amplitude of the detail coefficient of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal, and the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal. Based on the technical solution provided by the present invention, a variable time window design is adopted. Compared with the traditional timing window, a section of data with more obvious transient characteristics after the initial moment of the fault can be extracted for positioning calculation, which is conducive to improving the accuracy and reliability of positioning. The technical solution provided by the present invention does not require high-precision timing, is not affected by the complex structure of the distribution network line, can be reliably positioned, and is less affected by the type of fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a flow chart of a method for locating a traveling wave fault in a distribution network provided by the present invention;

[0055] Figure 2 is a schematic diagram of an analysis time window provided by an embodiment of the present invention;

[0056] Figure 3 It is a schematic diagram of the segmentation of the distribution network provided by an embodiment of the present invention;

[0057] Figure 4 The present invention is a schematic structural diagram of a distribution network traveling wave fault locating device provided by the present invention. DETAILED DESCRIPTION

[0058] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0059] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] This embodiment provides a method for locating traveling wave faults in a distribution network. Figure 1 As shown, including:

[0061] 101. Extracting transient characteristics of the voltage signal of the distribution network within the analysis time window and discretizing the transient characteristics of the voltage signal of the distribution network within the analysis time window;

[0062] 102. Determine the probability of failure in each section of the distribution network based on the discrete transient characteristics;

[0063] 103 determining the fault section of the distribution network according to the probability of faults occurring in each section of the distribution network;

[0064] Among them, the transient characteristics of the distribution network voltage signal include: the detail coefficient amplitude of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal and the ratio of the high frequency component to the low frequency component in the first half wave of the distribution network voltage signal.

[0065] The process of obtaining the analysis time window includes:

[0066] The voltage signal of the distribution network is decomposed into detail coefficients and approximate coefficients by using wavelet transform;

[0067] Extracting a modulus maximum sequence of the detail coefficients;

[0068] Based on the modulus maximum sequence of the detail coefficients, the initial time t at which the voltage signal of the distribution network fails is determined using the modulus maximum method. 0 , and the initial time t 0 As the initial moment of the analysis window;

[0069] The initial time t 0 The first modulus maximum in the modulus maximum sequence whose modulus maximum is greater than zero and less than the threshold ζ corresponds to time t e As the end time of the analysis window. Figure 2 As shown, the fault initial time 3066 is the initial time t of the analysis time window. 0 The resonance end time 3140 is the end time of the analysis window t e .

[0070] Obtaining the transient characteristics of the distribution network voltage signal includes: a process of obtaining the detail coefficient amplitude of the distribution network voltage signal at the initial moment of the fault, a process of obtaining the transient energy of the distribution network voltage signal, and a process of obtaining the ratio of the high-frequency component to the low-frequency component in the first half wave of the distribution network voltage signal.

[0071] Among them, the detail coefficient amplitude of the distribution network voltage signal at the initial moment of the fault is obtained according to the detail coefficient obtained by wavelet transform. The detail coefficient amplitude of the distribution network voltage signal at the initial moment of the fault is the initial fault amplitude. This transient feature can accurately reflect the degree of mutation of the fault instantaneous signal.

[0072] The process of acquiring the transient energy of the distribution network voltage signal includes:

[0073] Reconstructing the high frequency component of the power distribution network voltage signal using the detail coefficients;

[0074] The transient energy S of the distribution network voltage signal is determined by the following formula:

[0075]

[0076] Among them, U hfi To analyze the high-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t 0 ,t e ], n is the length of the analysis window, n = t e -t 0 , t e is the end time of the analysis window, t 0 is the initial time of the analysis window.

[0077] The process of obtaining the ratio of the high frequency part to the low frequency part in the first half wave of the distribution network voltage signal includes:

[0078] Reconstructing the high-frequency component of the distribution network voltage signal using the detail coefficients, and reconstructing the low-frequency component of the distribution network voltage signal using the approximate coefficients;

[0079] The ratio P of the high-frequency part to the low-frequency part in the first half-wave of the distribution network voltage signal is determined by the following formula:

[0080]

[0081] Among them, U hfi is the high-frequency component of the distribution network voltage signal at the i-th moment in the analysis time window, U lfi To analyze the low-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t 0 ,t e ],t e is the end time of the analysis window, t 0 is the initial time of the analysis window.

[0082] After the transient characteristics of the distribution network voltage signal are obtained, the transient characteristics of the distribution network voltage signal need to be discretized, including:

[0083] The amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to their absolute values, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0;

[0084] The transient energies of the distribution network voltage signals in the transient characteristics of the distribution network voltage signals monitored by all monitoring terminals in the distribution network are sorted in descending order according to the size of their absolute values, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the remaining monitoring terminals are defined as 0;

[0085] The ratios of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to the absolute value, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0.

[0086] In this embodiment, before the transient characteristics of the distribution network voltage signal are discretized, the distribution network line can be segmented, and the segmentation method is that two or three monitoring terminals form a line section, such as Figure 3 As shown, the distribution network line is divided into m sections through n monitoring terminals.

[0087] After the transient characteristics of the distribution network voltage signal are discretized, the probability of failure of each section in the distribution network needs to be determined according to the discretized transient characteristics. Therefore, step 102 includes:

[0088] The probability P of failure in section m is determined as follows: m :

[0089]

[0090] Among them, d m is the length of the line in section m, D is the total length of the distribution network line, P j is the probability of failure in section m corresponding to the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, j∈[1,s], s is the total number of monitoring terminals adjacent to section m.

[0091] The probability P of the fault in the section m corresponding to the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is j The acquisition process includes:

[0092] The probability P of the fault in the segment m corresponding to the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is determined as follows: j :

[0093]

[0094] Among them, P j1 is the probability of fault in section m corresponding to the amplitude of the detail coefficient at the initial moment of fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, is the probability of failure in section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, It is the probability of fault in section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the discrete distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to section m.

[0095] When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault in the section m corresponding to the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0;

[0096] When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy amplitude of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault of the section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0;

[0097] When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 4, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 3, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 2, the probability of fault in the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 1, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the section m fault corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0;

[0098] Where s is the total number of monitoring terminals adjacent to segment m.

[0099] After determining the probability of failure in each section of the distribution network according to the discrete transient characteristics, it is necessary to determine the fault section of the distribution network according to the probability of failure in each section of the distribution network. Therefore, step 103 includes obtaining the section with the highest probability of failure, and the section with the highest probability of failure is the fault section of the distribution network.

[0100] After determining the faulty section of the distribution network according to the probability of faults occurring in each section of the distribution network, the method may further include:

[0101] A single-ended traveling wave method is used to determine the fault point of the distribution network in the fault section of the distribution network.

[0102] Based on the same concept of the above method, the present invention also provides a distribution network traveling wave fault location device, such as Figure 4 As shown, the device comprises:

[0103] A data processing unit, used to extract the transient characteristics of the distribution network voltage signal within the analysis time window and discretize the transient characteristics of the distribution network voltage signal within the analysis time window;

[0104] A first determination unit is used to determine the probability of failure of each section in the distribution network according to the discretized transient characteristics;

[0105] A second determining unit, configured to determine a faulty section of the distribution network according to a probability of a fault occurring in each section of the distribution network;

[0106] Among them, the transient characteristics of the distribution network voltage signal include: the detail coefficient amplitude of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal and the ratio of the high frequency component to the low frequency component in the first half wave of the distribution network voltage signal.

[0107] The data processing unit includes: an acquisition module for acquiring the analysis time window;

[0108] The acquisition module comprises:

[0109] A decomposition submodule, used for decomposing the voltage signal of the distribution network into detail coefficients and approximate coefficients by using wavelet transform;

[0110] An extraction submodule, used for extracting a modulus maximum sequence of the detail coefficients;

[0111] The first determination submodule is used to determine the initial time t when the voltage signal of the distribution network fails based on the modulus maximum sequence of the detail coefficients by using the modulus maximum method. 0 , and the initial time t 0 As the initial moment of the analysis window;

[0112] The second determination submodule is used to set the initial time t 0 The first modulus maximum in the modulus maximum sequence whose modulus maximum is greater than zero and less than the threshold ζ corresponds to time t e As the end time of the analysis window.

[0113] The process of acquiring the transient energy of the distribution network voltage signal includes:

[0114] Reconstructing the high frequency component of the power distribution network voltage signal using the detail coefficients;

[0115] The transient energy S of the distribution network voltage signal is determined by the following formula:

[0116]

[0117] Among them, U hfi To analyze the high-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t 0 ,te ], n is the length of the analysis window, n = t e -t 0 , t e is the end time of the analysis window, t 0 is the initial time of the analysis window.

[0118] The process of obtaining the ratio of the high frequency part to the low frequency part in the first half wave of the distribution network voltage signal includes:

[0119] Reconstructing the high-frequency component of the distribution network voltage signal using the detail coefficients, and reconstructing the low-frequency component of the distribution network voltage signal using the approximate coefficients;

[0120] The ratio P of the high-frequency part to the low-frequency part in the first half-wave of the distribution network voltage signal is determined by the following formula:

[0121]

[0122] Among them, U hfi is the high-frequency component of the distribution network voltage signal at the i-th moment in the analysis time window, U lfi To analyze the low-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t 0 ,t e ],t e is the end time of the analysis window, t 0 is the initial time of the analysis window.

[0123] The data processing unit is specifically used for:

[0124] The amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to their absolute values, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0;

[0125] The transient energies of the distribution network voltage signals in the transient characteristics of the distribution network voltage signals monitored by all monitoring terminals in the distribution network are sorted in descending order according to the size of their absolute values, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the remaining monitoring terminals are defined as 0;

[0126] The ratios of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to the absolute value, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0.

[0127] The first determining unit is specifically configured to:

[0128] The probability P of failure in section m is determined as follows: m :

[0129]

[0130] Among them, d m is the length of the line in section m, D is the total length of the distribution network line, P j is the probability of failure in section m corresponding to the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, j∈[1,s], s is the total number of monitoring terminals adjacent to section m.

[0131] The probability P of the fault in the section m corresponding to the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is j The acquisition process includes:

[0132] The probability P of the fault in the segment m corresponding to the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is determined as follows: j :

[0133]

[0134] Among them, P j1 is the probability of fault in section m corresponding to the amplitude of the detail coefficient at the initial moment of fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, is the probability of failure in section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, It is the probability of fault in section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the discrete distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to section m.

[0135] When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault in the section m corresponding to the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0;

[0136] When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy amplitude of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault of the section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0;

[0137] When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 4, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 3, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 2, the probability of fault in the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 1, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the section m fault corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0;

[0138] Where s is the total number of monitoring terminals adjacent to segment m.

[0139] The second determining unit is specifically configured to:

[0140] The section with the highest probability of failure is obtained, and the section with the highest probability of failure is the distribution network failure section.

[0141] After the second determining unit, the method further includes:

[0142] The third determining unit is used to determine the fault point of the distribution network in the fault section of the distribution network by using a single-ended traveling wave method.

[0143] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0144] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0145] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0146] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for locating traveling wave faults in a distribution network, characterized in that: The method comprises: Extracting transient characteristics of the distribution network voltage signal within the analysis time window and discretizing the transient characteristics of the distribution network voltage signal within the analysis time window; Determine the probability of failure in each section of the distribution network based on the discretized transient characteristics; Determining a fault section of the distribution network according to the probability of failure of each section in the distribution network; The transient characteristics of the distribution network voltage signal include: the amplitude of the detail coefficient of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal, and the ratio of the high frequency component to the low frequency component in the first half wave of the distribution network voltage signal; Determining the probability of failure of each section in the distribution network according to the discretized transient characteristics includes: The probability P of failure in section m is determined as follows: m : Among them, d m is the length of the line in section m, D is the total length of the distribution network line, P j is the probability of failure in section m corresponding to the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, j∈[1,s], s is the total number of monitoring terminals adjacent to section m.

2. The method according to claim 1, characterized in that The process of obtaining the analysis time window includes: The voltage signal of the distribution network is decomposed into detail coefficients and approximate coefficients by using wavelet transform; Extracting a modulus maximum sequence of the detail coefficients; Based on the modulus maximum sequence of the detail coefficients, the initial time t0 when the voltage signal of the distribution network fails is determined by using the modulus maximum method, and the initial time t0 is used as the initial time of the analysis time window; The first modulus maximum value in the modulus maximum sequence after the initial time t0 whose modulus maximum value is greater than zero and less than the threshold ζ corresponds to the time t e As the end time of the analysis window.

3. The method according to claim 2, characterized in that The process of acquiring the transient energy of the distribution network voltage signal includes: Reconstructing the high frequency component of the power distribution network voltage signal using the detail coefficients; The transient energy S of the distribution network voltage signal is determined by the following formula: Among them, U hfi To analyze the high-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t0,t e ], n is the length of the analysis window, n = t e -t0,t e is the end time of the analysis window, and t0 is the initial time of the analysis window.

4. The method according to claim 2, characterized in that The process of obtaining the ratio of the high frequency part to the low frequency part in the first half wave of the distribution network voltage signal includes: Reconstructing the high-frequency component of the distribution network voltage signal using the detail coefficients, and reconstructing the low-frequency component of the distribution network voltage signal using the approximate coefficients; The ratio P of the high-frequency part to the low-frequency part in the first half-wave of the distribution network voltage signal is determined by the following formula: Among them, U hfi is the high-frequency component of the distribution network voltage signal at the i-th moment in the analysis time window, U lfi To analyze the low-frequency component of the distribution network voltage signal at the i-th moment in the time window, i∈[t0,t e ],t e is the end time of the analysis window, and t0 is the initial time of the analysis window.

5. The method according to claim 1, characterized in that The step of discretizing the transient characteristics of the distribution network voltage signal comprises: The amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to their absolute values, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the amplitudes of the detail coefficients at the initial moment of the fault in the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0; The transient energies of the distribution network voltage signals in the transient characteristics of the distribution network voltage signals monitored by all monitoring terminals in the distribution network are sorted in descending order according to the size of their absolute values, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the transient energies in the transient characteristics of the distribution network voltage signals corresponding to the remaining monitoring terminals are defined as 0; The ratios of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by all monitoring terminals in the distribution network are sorted in descending order according to the absolute value, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the first four monitoring terminals with the largest absolute values ​​are defined as 4, 3, 2, and 1, and the ratios of the high-frequency component to the low-frequency component in the first half-wave of the transient characteristics of the distribution network voltage signal corresponding to the remaining monitoring terminals are defined as 0.

6. The method according to claim 1, characterized in that The probability P of the fault in the section m corresponding to the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is j The acquisition process includes: The probability P of the fault in the segment m corresponding to the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is determined as follows: j : Among them, P j1 is the probability of fault in section m corresponding to the amplitude of the detail coefficient at the initial moment of fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, is the probability of failure in section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, It is the probability of fault in section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the discrete distribution network voltage signal in the transient characteristics of the distribution network voltage signal monitored by the monitoring terminal j adjacent to section m.

7. The method according to claim 6, characterized in that When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the amplitude of the detail coefficient at the initial time of the fault in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault in the section m corresponding to the amplitude of the detail coefficient at the initial moment of the fault in the transient characteristics of the voltage signal of the distribution network after discretization monitored by the monitoring terminal j adjacent to the section m is 0; When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 4, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 3, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 2, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is 1, the probability of the segment m fault corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the segment m is When the transient energy amplitude of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the fault of the section m corresponding to the transient energy of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0; When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 4, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 3, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 2, the probability of fault in the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 1, the probability of failure of the section m corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is When the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0, the probability of the section m fault corresponding to the ratio of the high-frequency component to the low-frequency component in the first half-wave of the distribution network voltage signal in the transient characteristics of the discrete distribution network voltage signal monitored by the monitoring terminal j adjacent to the section m is 0; Where s is the total number of monitoring terminals adjacent to segment m.

8. The method according to claim 1, characterized in that The determining the fault section of the distribution network according to the probability of faults occurring in each section of the distribution network comprises: The section with the highest probability of failure is obtained, and the section with the highest probability of failure is the distribution network failure section.

9. The method according to claim 1, characterized in that After determining the fault section of the distribution network according to the probability of failure of each section in the distribution network, the method further comprises: A single-ended traveling wave method is used to determine the fault point of the distribution network in the fault section of the distribution network.

10. A distribution network traveling wave fault location device, characterized in that: The device comprises: A data processing unit, used to extract the transient characteristics of the distribution network voltage signal within the analysis time window and discretize the transient characteristics of the distribution network voltage signal within the analysis time window; A first determination unit is used to determine the probability of failure of each section in the distribution network according to the discretized transient characteristics; A second determining unit, configured to determine a faulty section of the distribution network according to a probability of a fault occurring in each section of the distribution network; The transient characteristics of the distribution network voltage signal include: the amplitude of the detail coefficient of the distribution network voltage signal at the initial moment of the fault, the transient energy of the distribution network voltage signal, and the ratio of the high frequency component to the low frequency component in the first half wave of the distribution network voltage signal; The first determining unit includes: The probability P of failure in section m is determined as follows: m : Among them, d m is the length of the line in section m, D is the total length of the distribution network line, P j is the probability of failure in section m corresponding to the transient characteristics of the discretized distribution network voltage signal monitored by the monitoring terminal j adjacent to section m, j∈[1,s], s is the total number of monitoring terminals adjacent to section m.

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