New energy overhead current collection line grounding fault positioning method based on tower fault grounding current transient characteristics

Abstract

The invention discloses a new energy overhead current collection line grounding fault positioning method based on tower fault grounding current transient characteristics, and belongs to the field of power system control protection. The method comprises the following steps: firstly, acquiring fault grounding current recording data of all towers of a fault line, and then preliminarily screening out sampling data containing high-frequency characteristic components; thirdly, an energy spectrum is obtained through wavelet packet decomposition, and a suspected fault tower is selected; and then, in a suspected fault tower range, carrying out empirical mode decomposition on the obtained fault earth current sampling data, obtaining the mode component and transient energy of the earth fault current of each suspected fault tower, comparing the mode component and transient energy with a set fault transient energy threshold, and accurately screening out the fault tower. Therefore, accurate positioning of the faulted tower level is realized. The method is hardly influenced by transition resistance, tower span and fault distance, the denoising capability is high, the reliability of the distance measurement result is high, and the specific tower with the fault can be accurately identified.

Description

Technical Field

[0001] The present invention belongs to the field of relay protection of electric power systems, and in particular relates to a method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground currents caused by tower faults. Background Art

[0002] Since most of the new energy stations are located in areas with relatively harsh meteorological conditions, affected by climatic conditions and geographical environment, grounding and short-circuit faults occur more frequently in their overhead collector lines than in the transmission and distribution network, among which instantaneous single-phase grounding faults account for a high proportion. Since overhead collector lines are generally not equipped with automatic reclosing switches, faults in overhead collector lines will directly lead to the shutdown of related new energy power generation units connected to the grid, and the power outage losses caused by long-term fault finding are huge. Especially for instantaneous grounding faults with slight fault traces, it is very difficult to manually find and confirm the fault point on site. The current grounding fault location method applied to transmission and distribution lines mainly uses the fault electrical quantity of the line to achieve section positioning or fault distance measurement, which cannot be well applied to the positioning requirements of the characteristics of the collector line, so a reliable and fast collector line grounding fault location solution is urgently needed. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for locating ground faults of new energy overhead collector lines based on the transient characteristics of the ground current entering the tower fault. The method is almost unaffected by the transition resistance and the fault distance, has strong denoising capability, high ranging result accuracy, and can accurately identify the fault location.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground currents caused by tower faults, comprising the following steps: Step 1: Obtain the fault ground current recording data of all towers in the fault line section, and preliminarily filter out the sampling data containing high-frequency characteristic components; Step 2: Decompose the selected sampling data by wavelet packets and draw the corresponding energy spectrum. Use the ratio of low-frequency energy to total energy to define the range of suspected faulty towers. Step 3: Perform empirical mode decomposition on the fault current of the suspected faulty tower to obtain the modal components of the fault current and its transient energy; Step 4: Calculate the energy proportion of the ground current of the suspected faulty tower, and determine whether it meets the energy proportion threshold. The energy entropy that meets the threshold constructs an identification matrix to determine the faulty tower and achieve accurate fault location. Preferably, in Step 1, when a fault occurs in the renewable energy overhead collection line, the fault line selection and phase selection of the renewable energy overhead collection line are first completed by using the fault recording of the booster station, the fault line is determined, and the fault ground current recording data of all towers of the fault line at the moment of the fault are obtained.

[0005] Preferably, in Step 1, a current measurement and fault recording device is installed on the tower foundation grounding wire to reliably collect and record ground current data and form a recording file.

[0006] Preferably, in Step 1, the sampled data containing high-frequency characteristic components is preliminarily screened out, and the steps are as follows: The fault ground current recording data of all towers of the fault line are subjected to short-time Fourier transform, and the tower ground current recording data containing high-frequency characteristic components are screened out through amplitude-frequency domain analysis.

[0007] Preferably, in the Step 2, the selected sampling data is subjected to wavelet packet decomposition, and the corresponding energy spectrum is plotted, and the ratio of low-frequency energy to total energy is used to define the range of the faulty tower; the waveform signal is x(t), and after j layers of wavelet packet decomposition, the following formula can be obtained: ; ; In the above formula, , , is the wavelet packet function, j is the scale index, is the position index and i is the frequency index. , , is a set of orthogonal basis functions; The total energy of the signal waveform is: ; in Represents the frequency band signal energy in the i-th segment; the original signal energy synthesis is the sum of the signal energy of each frequency band; The energy distribution is analyzed by using the characteristics of wavelet packet decomposition, so as to obtain the distribution characteristics of low-frequency energy and high-frequency energy of distribution line current, and construct the discrimination coefficient Q, that is, the ratio of low-frequency energy proportion to high-frequency energy proportion, to realize the demarcation of suspected faulty towers and non-faulty towers.

[0008] Preferably, in Step 3, empirical mode decomposition is performed on the fault ground current of the identified suspected faulty tower to obtain the fault current modal components and transient energy thereof.

[0009] Preferably, in Step 3, the empirical mode decomposition can decompose the sampled data into a set of intrinsic mode function (IMF) components and residuals, each component signal has different frequency and amplitude characteristics, and can effectively extract fault features. The formula is as follows: ; in, For sampling data Different components from high frequency band to low frequency band; i is the signal index, i=1,2,3…,n; For the remaining amount.

[0010] Preferably, in Step 3, the fault current modal component and its transient energy are calculated as follows: ; Where: is the transient energy of the fault current modal component, is the sampling point number; The number of sampling points for half a cycle; are the fault current modal components under different conditions.

[0011] Preferably, in the Step 4, the energy proportion of the ground current of the suspected faulty tower is calculated, and by judging whether the energy proportion threshold is met, an identification matrix is ​​constructed based on the energy entropy that meets the threshold, the faulty tower is determined, and the fault is accurately located; The energy proportion matrix of the ground current of the suspected fault tower fault is obtained by further processing the transient energy of the fault current modal component and calculating the energy proportion of the corresponding component. The formula is as follows: ; Where: is the energy proportion of the current IMFk component under different conditions; is the energy sum of the fault current IMFk component corresponding to all towers; the transient energy proportion of the current IMFk component under different conditions satisfies ; As the judgment threshold, the corresponding energy entropy is used to construct an identification matrix to determine the faulty tower and achieve accurate fault location.

[0012] A new energy overhead collector line ground fault location system based on transient characteristics of pole tower fault ground current, adopting a new energy overhead collector line ground fault location method based on transient characteristics of pole tower fault ground current, comprising: Signal acquisition module: used to obtain the fault ground current recording data of all towers in the fault line section, and preliminarily screen out the sampling data containing high-frequency characteristic components; Screening module: used to perform wavelet packet decomposition on the screened sampled data, draw the corresponding energy spectrum, and use the ratio of low-frequency energy to total energy to define the range of suspected faulty towers; Analysis module: used to perform empirical mode decomposition on the fault current of the suspected faulty tower, and obtain the modal components of the fault current and its transient energy; Calculation output module: used to calculate the energy ratio of the ground current of the suspected faulty tower, and to determine whether the energy ratio threshold is met. The energy entropy that meets the threshold is used to construct an identification matrix, identify the faulty tower, and achieve accurate fault location.

[0013] The present invention can achieve the following beneficial effects: The present invention simulates and analyzes the transient characteristics of ground faults in collector lines of new energy fields, explores the current shunting mechanism of faulty ground wires, faulty pole towers and adjacent pole towers, and combines the analysis of the energy spectrum, polarity and time-frequency domain of unique transient electrical quantities to achieve reliable determination of faulty pole towers, ultimately achieving improved economic benefits for new energy power generation companies.

[0014] The present invention can eliminate the noise and low-frequency impurity signals contained in the original fault signal while retaining its original characteristics, thereby improving the accurate extraction of fault information. In addition, it can operate correctly under different fault types, fault distances, fault starting angles and transition resistances. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Figure 1 A topological diagram of the application scenario of the present invention; Figure 2 It is a flow chart of the present invention; Figure 3 It is the waveform diagram of the ground current of tower 2; Figure 4 The ground current waveform of the tower 3; Figure 5 It is the waveform diagram of the ground current of the tower 4 where the fault is located; Figure 6 It is the waveform diagram of the ground current of tower 5; Figure 7 It is the waveform diagram of the ground current of the tower 6; Figure 8 It is the spectrum energy diagram of the ground current of tower 2 and tower 6 after wavelet packet decomposition; Fig. 9 It is the spectrum energy diagram of the ground current of tower 3 and tower 5 after wavelet packet decomposition; Fig.10 It is the spectrum energy diagram of the ground current of fault tower 4 after wavelet packet decomposition; Fig.11 The waveform diagram of each modal component of the ground current of towers 2, 3, and 4 after empirical mode decomposition. DETAILED DESCRIPTION

[0016] The preferred solution is Figures 1 to 11 As shown, a method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground currents caused by tower faults is provided, and the steps are as follows: Step 1: Obtain the fault ground current recording data of all towers in the fault line section, and preliminarily filter out the sampling data containing high-frequency characteristic components; Step 2: Decompose the selected sampling data by wavelet packet, draw the corresponding energy spectrum, and use the ratio of low-frequency energy to total energy to define the range of the faulty tower; Step 3: Perform empirical mode decomposition on the fault current of the tower to obtain the transient energy of the optimal fault current modal component; Step 4: Calculate the energy proportion of the ground current of the suspected faulty tower, determine whether it meets the energy proportion threshold, and construct an identification matrix with the energy entropy that meets the threshold, determine the faulty tower, and achieve accurate fault location; Furthermore, in Step 1: Step1.1: For the collection of fault ground current of all towers in the fault line section, when a fault occurs, it is necessary to first complete the fault line selection, fault phase identification and fault section location of the new energy overhead collection line, and then obtain the fault ground current recording data of all towers.

[0017] Step 1.2: By installing current measuring devices and wave recording devices on the tower base grounding wire, the ground current conditions can be reliably detected and data can be obtained.

[0018] Furthermore, in Step 2: Step 2.1: The selected sampling data is decomposed by wavelet packets, and the corresponding energy spectrum is plotted. The ratio of low-frequency energy to total energy is used to define the range of the faulty tower. The waveform signal is x(t), and after j layers of wavelet packet decomposition, the following formula can be obtained:

[0019]

[0020] In the above formula, , , is the wavelet packet function, j is the scale index, is the position index and i is the frequency index. , , is a set of orthogonal basis functions.

[0021] The total energy of the signal waveform is:

[0022] in Represents the frequency band signal energy in the i-th segment. The original signal energy synthesis is the sum of the signal energy of each frequency band.

[0023] Step 2.2: By using the characteristics of wavelet packet decomposition, the energy distribution is analyzed to obtain the characteristics of low-frequency energy and high-frequency energy distribution of the distribution line current, and the discrimination coefficient Q, that is, the ratio of the low-frequency energy proportion to the high-frequency energy proportion, is constructed to realize the demarcation of faulty towers and non-faulty towers. If the energy discrimination coefficient is less than 50, it is a faulty tower. However, based on the wavelet theory analysis, it can be known that when a single-phase grounding fault occurs in the tower and the grounding resistance of the faulty tower is 50Ω, the transient current will fail and the faulty tower cannot be judged. Therefore, subsequent steps are required to perform auxiliary analysis to improve the grounding fault location method of the present invention.

[0024] Furthermore, in Step 3: Step 3.1: The fault current of the tower is subjected to empirical mode decomposition to obtain the transient energy of the optimal fault current modal component.

[0025] Step 3.2: The empirical mode decomposition can decompose the sampled data into a set of intrinsic mode function (IMF) components and residuals. Each component signal has different frequency and amplitude characteristics, and can effectively extract fault features. The specific formula is as follows:

[0026] in, For sampling data Different components from high frequency band to low frequency band; i is the signal index, i=1,2,3…,n; For the remaining amount.

[0027] Step3.3: The transient energy of the optimal fault current modal component is calculated as follows:

[0028] Where: is the transient energy of the fault current modal component, is the sampling point number; The number of sampling points for half a cycle; are the fault current modal components under different conditions.

[0029] Furthermore, in Step 4: Step 4.1: Calculate the energy proportion of the ground current of the suspected faulty tower, determine whether it meets the energy proportion threshold, and construct an identification matrix based on the energy entropy that meets the threshold, determine the faulty tower, and achieve accurate fault location; The energy proportion matrix of the ground current of the suspected fault tower fault is obtained by further processing the transient energy of the fault current modal component obtained in the previous step to calculate the energy proportion of the corresponding component. The specific formula is as follows:

[0030] Where: is the energy proportion of the current IMFk component under different conditions; is the energy sum of the fault current IMFk components corresponding to all towers. The transient energy proportion of the current IMFk component under different conditions satisfies ( As the judgment threshold), the corresponding energy entropy is used to construct the identification matrix to determine the faulty tower and realize accurate fault location.

[0031] Embodiment 1: Figure 1 This is a schematic diagram of an application scenario of a method for locating ground faults in overhead collector lines of new energy sources based on transient characteristics of ground currents caused by tower faults. The distribution network simulation model is a distribution network simulation model built according to the actual operation of the distribution network, and PSCAD / EMTDC is used to establish Figure 1In the distribution network simulation model shown, the 110kV / 35kV substation has two outgoing lines (both are overhead lines), L1=10.3km and L2=10.3km. Since the present invention locates the grounding fault by targeting the faulty tower, and the overhead collection lines of new energy are generally composed of overhead lines, most of the faults occur at the tower position. Therefore, the fault positions involved have been set as the tower positions, and the common spans of 300 meters, 200 meters, and 100 meters are used as the minimum scale for the simulated fault distance. The positive sequence impedance of the overhead line is: R1=0.45Ω / km, L1=1.172mH / km, C1=6.1nF / km, and the zero sequence impedance is: R0=0.7Ω / km, L0=3.91mH / km, C0=3.8nF / km; the model of the overhead conductor is LGj-210 / 35, and the model of the overhead ground wire is Gj-25; the fault points are all located at the central tower, and the data collection is based on the fault tower and the adjacent left and right towers, a total of five towers. The initial fault angle is 90°, the transition resistance is 0Ω, and the grounding resistance of the fault tower is 10Ω, 20Ω, and 30Ω.

[0032] The embodiment of the present invention provides a method for locating a ground fault of a new energy overhead collector line based on transient characteristics of a tower fault ground current, including: Step 1: Obtain the fault ground current recording data of all towers in the fault line section, and preliminarily filter out the sampling data containing high-frequency characteristic components; Among them, if the fault recording equipment has been installed on site and has the ability to export data, there is no need to reinstall it; at the location of the overhead line tower, no matter the fault line is grounded through a lightning arrester or through an insulator, the grounding current must enter the ground through the tower grounding wire. Installing a current measurement and recording device on the tower base grounding wire can reliably indicate the grounding condition of the tower location. This function is the tower base grounding monitoring, which can accurately indicate the grounding position in the case of a line grounding fault through the tower. For the collection of the fault current entering the ground of all towers in the fault line section, when a fault occurs, it is necessary to first complete the fault line selection, fault phase identification and fault section location of the new energy overhead collector line, and then obtain the fault current recording data of all towers. For example, Figure 2-6 As shown in the figure (the faulty tower is ), when the collected ground current data is close to the fault location, it can be clearly seen that the high-frequency transient component of the data is increasing, and even the towers far away from the fault location may have no ground current. Combining the above characteristics, the required data can be preliminarily screened out.

[0033] Step 2: Decompose the selected sampling data by wavelet packet, draw the corresponding energy spectrum, and use the ratio of low-frequency energy to total energy to define the range of the faulty tower; The selected sampling data is decomposed by wavelet packets, and the corresponding energy spectrum is plotted. The ratio of high-frequency band energy to total energy is used to define the range of the faulty tower. The waveform signal is x(t), and after j layers of wavelet packet decomposition, the following formula can be obtained:

[0034]

[0035] In the above formula, , , is the wavelet packet function, j is the scale index, is the position index and i is the frequency index. , , is a set of orthogonal basis functions.

[0036] The total energy of the signal waveform is:

[0037] in Represents the energy of the frequency band signal in the i-th segment. The original signal energy synthesis is the sum of the energy of each frequency band signal.

[0038] Since the signal contains a large amount of power frequency energy, the obtained energy spectrum effect will be insufficient, so the energy mentioned above is to omit the power frequency band, and the remaining frequency bands are all high-frequency fault frequency bands. Figure 7-9 As shown, since the high-frequency energy segments of the two-stage towers before and after the fault are similar, they will not be elaborated in the figure. Through the display of frequency band energy, it can be concluded that the high-frequency energy proportion of the faulty tower is higher than that of the non-faulty tower.

[0039] By using the characteristics of wavelet packet decomposition, the energy distribution is analyzed to obtain the characteristics of low-frequency energy and high-frequency energy distribution of the distribution line current, and the discrimination coefficient Q, that is, the ratio of the low-frequency energy proportion to the high-frequency energy proportion, is constructed to realize the demarcation of faulty towers and non-faulty towers. If the energy discrimination coefficient is less than 50, it is a faulty tower. However, based on the wavelet theory analysis, it can be known that when a single-phase grounding fault occurs in the tower and the grounding resistance of the faulty tower is 50Ω, the transient current will fail and the faulty tower cannot be judged. Therefore, subsequent steps are required to perform auxiliary analysis to improve the grounding fault location method of the present invention.

[0040] Step 3: Perform empirical mode decomposition on the fault current of the tower to obtain the transient energy of the optimal fault current modal component; Among them, exemplary ones are Fig.10As shown in the figure, the frequency components of towers 2, 3, and 4 after empirical mode decomposition. By calculating the energy value of each modal component of each tower, it can be seen from the figure that when K=3, the amplitude of the fault current IMF3 component is larger than that of IMF2 and IMF4, the fault characteristics are obvious, and correct fault judgment can be achieved. Therefore, the number of modal components K of EMD should be 3. It can be seen from the empirical mode decomposition that IMF3 has the best effect.

[0041] The empirical mode decomposition algorithm is an existing algorithm, and its specific operation process is not repeated in this application. The algorithm combining wavelet packet decomposition energy ratio with empirical mode decomposition is almost unaffected by the tower grounding transition resistance, fault type and distance, and has high positioning accuracy and good reliability.

[0042] Step 4: Calculate the energy proportion of the ground current of the suspected faulty tower, determine whether it meets the energy proportion threshold, and construct an identification matrix with the energy entropy that meets the threshold, determine the faulty tower, and achieve accurate fault location; The energy proportion matrix of the ground current of the suspected fault tower fault is obtained by further processing the transient energy of the fault current modal component obtained in the previous step to calculate the energy proportion of the corresponding component. The specific formula is as follows:

[0043] Where: is the energy proportion of the current IMFk component under different conditions; is the energy sum of the fault current IMFk components corresponding to all towers. The transient energy proportion of the current IMFk component under different conditions satisfies ( As the judgment threshold), the corresponding energy entropy is used to construct the identification matrix to determine the faulty tower and realize accurate fault location.

[0044] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for locating ground faults in overhead collector lines of new energy sources based on transient characteristics of ground currents caused by tower faults, characterized in that The following steps are involved: Step 1: Obtain the fault ground current recording data of all towers in the fault line section, and preliminarily filter out the sampling data containing high-frequency characteristic components; Step 2: Decompose the selected sampling data by wavelet packets and draw the corresponding energy spectrum. Use the ratio of low-frequency energy to total energy to define the range of suspected faulty towers. Step 3: Perform empirical mode decomposition on the fault current of the suspected faulty tower to obtain the modal components of the fault current and its transient energy; Step 4: Calculate the energy proportion of the ground current of the suspected faulty tower, and determine whether the energy proportion threshold is met. The energy entropy that meets the threshold is used to construct an identification matrix to determine the faulty tower and accurately locate the fault.

2. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by tower faults according to claim 1, characterized in that: In the Step 1, when a fault occurs in the renewable energy overhead collection line, the fault line selection and phase selection of the renewable energy overhead collection line are first completed by using the fault recording of the booster station, the fault line is determined, and the fault ground current recording data of all towers of the fault line at the moment of the fault are obtained.

3. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by tower faults according to claim 1, characterized in that: In the Step 1, a current measurement and fault recording device is installed on the tower foundation grounding wire to reliably collect and record ground current data and form a recording file.

4. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by tower faults according to claim 1, characterized in that: In the Step 1, the sample data containing high-frequency characteristic components is initially screened out, and the steps are as follows: The fault ground current recording data of all towers of the fault line are subjected to short-time Fourier transform, and the tower ground current recording data containing high-frequency characteristic components are screened out through amplitude-frequency domain analysis.

5. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by tower faults according to claim 1, characterized in that: In the Step 2, the selected sampling data is decomposed by wavelet packets, and the corresponding energy spectrum is plotted. The ratio of low-frequency energy to total energy is used to define the range of the faulty tower. The waveform signal is x(t), and after j layers of wavelet packet decomposition, the following formula can be obtained: ； ； In the above formula, , , is the wavelet packet function, j is the scale index, is the position index, i is the frequency index; , , is a set of orthogonal basis functions; The total energy of the signal waveform is: ； in represents the frequency band signal energy within the i-th segment; The original signal energy synthesis is the sum of the signal energy in each frequency band; The energy distribution is analyzed by using the characteristics of wavelet packet decomposition, so as to obtain the distribution characteristics of low-frequency energy and high-frequency energy of distribution line current, and construct the discrimination coefficient Q, that is, the ratio of low-frequency energy proportion to high-frequency energy proportion, to realize the demarcation of suspected faulty towers and non-faulty towers.

6. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by tower faults according to claim 1, characterized in that: In the Step 3, empirical mode decomposition is performed on the fault ground current of the identified suspected faulty tower to obtain the fault current modal components and transient energy thereof.

7. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by tower faults according to claim 1, characterized in that: In Step 3, the empirical mode decomposition can decompose the sampled data into a set of intrinsic mode function components and residuals. Each component signal has different frequency and amplitude characteristics, and can effectively extract fault features. The formula is as follows: ； in, For sampling data Different components from high frequency band to low frequency band; i is the signal index, i=1,2,3…,n; For the remaining amount.

8. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by a tower fault according to claim 7, characterized in that: In Step 3, the fault current modal component and its transient energy are calculated as follows: ； Where: is the transient energy of the fault current modal component, is the sampling point number; is the number of sampling points in half a cycle; are the fault current modal components under different conditions.

9. A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground current caused by tower faults according to claim 8, characterized in that: In the Step 4, the energy proportion of the ground current of the suspected faulty tower is calculated, and by judging whether the energy proportion threshold is met, the energy entropy that meets the threshold is used to construct an identification matrix, the faulty tower is determined, and the fault is accurately located; The energy proportion matrix of the ground current of the suspected fault tower fault is obtained by further processing the transient energy of the fault current modal component and calculating the energy proportion of the corresponding component. The formula is as follows: ； Where: is the energy proportion of the current IMFk component under different conditions; is the energy sum of the fault current IMFk component corresponding to all towers; the transient energy proportion of the current IMFk component under different conditions satisfies ; As the judgment threshold, the corresponding energy entropy is used to construct an identification matrix to determine the faulty tower and achieve accurate fault location.

10. A new energy overhead collector line ground fault location system based on the transient characteristics of the ground current caused by a tower fault, characterized by: A method for locating ground faults of new energy overhead collector lines based on transient characteristics of ground currents caused by tower faults according to any one of claims 1 to 9 is adopted, comprising: Signal acquisition module: used to obtain the fault ground current recording data of all towers in the fault line section, and preliminarily screen out the sampling data containing high-frequency characteristic components; Screening module: used to perform wavelet packet decomposition on the screened sampled data, draw the corresponding energy spectrum, and use the ratio of low-frequency energy to total energy to define the range of suspected faulty towers; Analysis module: used to perform empirical mode decomposition on the fault current of the suspected faulty tower, and obtain the modal components of the fault current and its transient energy; Calculation output module: used to calculate the energy ratio of the ground current of the suspected faulty tower, and to determine whether the energy ratio threshold is met. The energy entropy that meets the threshold is used to construct an identification matrix, identify the faulty tower, and achieve accurate fault location.

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