Ground wire single-end fault positioning method in ice melting operation

Abstract

The invention provides a ground wire single-end fault positioning method in ice melting operation, and the method comprises the steps: extracting positioning parameters of an initial wave and a second wave generated by a line fault through employing the traveling wave data of a measurement end; the positioning parameters comprise arrival time and polarity; determining a fault generation end by using the polarities of the initial wave and the second wave; the fault generating end is a measuring end or a far end; and positioning a fault point of the ground wire by using the wave velocity of the ground wire, the fault generation end and the arrival time of the initial wave and the second wave. According to the invention, through the single-end fault transient signal capturing and self-adaptive filtering technology, the positioning of the ground wire fault in the ice melting operation is completed, and the problem of fault detection in a strong interference environment is solved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of DC ice-melting of power transmission lines, and more particularly to a method for single-ended fault location of ground wires in ice-melting operation. BACKGROUND

[0002] The ice-melting operation of UHV DC power transmission lines is a key technology for ensuring the safe operation of energy arteries, and its core significance lies in actively eliminating the icing threat of the lines through the large-current ice-melting technology, preventing major accidents such as tower collapse and line breakage, and ensuring the stable operation of projects such as “West-to-East Power Transmission” under extreme weather conditions. The technology uses a DC power supply, which has the advantages of high efficiency and live-line operation compared with traditional AC ice-melting, and maintains uninterrupted power transmission across regions. Under this background, the failure of the traditional double-ended positioning method in fault location due to induced voltage interference, communication interruption or missing data on the opposite side will cause huge economic losses in the ice-melting working condition. SUMMARY

[0003] In view of the above problems, the present disclosure provides a method for single-ended fault location of ground wires in ice-melting operation using single-ended data.

[0004] The present disclosure provides a method for single-ended fault location of ground wires in ice-melting operation, characterized in that it comprises: using the traveling wave data of the measurement end to extract the positioning parameters of the initial wave and the second wave generated by the line fault; the positioning parameters include the arrival time and the polarity; using the polarity of the initial wave and the second wave to determine the fault generation end; the fault generation end is the measurement end or the far end; using the ground wire wave speed, the fault generation end and the arrival time of the initial wave and the second wave to locate the fault point of the ground wire.

[0005] According to the embodiments of the present disclosure, the traveling wave data generated by the line fault is obtained by the Rogowski coil equipped at the capacitor between the UHV DC power transmission line and the ground, and the arrival time of the initial wave and the second wave is extracted from the traveling wave data using the kurtosis, and the polarity of the initial wave and the second wave is extracted from the traveling wave data using the dual-tree complex wavelet transform.

[0006] According to the embodiments of the present disclosure, the arrival time of the initial wave and the second wave is extracted from the traveling wave data using the kurtosis, which comprises: for each sampling point in the traveling wave data, the kurtosis corresponding to the sampling point is calculated using the traveling wave data before the sampling point; the arrival time of the initial wave is determined using the sampling point corresponding to the maximum value of the kurtosis; the arrival time of the second wave is determined using the sampling point corresponding to the first kurtosis maximum value after the arrival time of the initial wave.

[0007] According to an embodiment of the present disclosure, the polarities of the initial wave and the second wave are extracted from the traveling wave data by using a dual-tree complex wavelet transform, including: determining the effective wave head of the traveling wave data by searching the modulus maximum points in the neighborhood of the arrival time of the initial wave and the second wave through the dual-tree complex wavelet transform; and determining the polarities of the initial wave and the second wave according to the effective wave head and a polarity determination rule.

[0008] According to an embodiment of the present disclosure, the fault generation end is determined by using the polarities of the initial wave and the second wave, including: determining that the fault generation end is the far end in response to the polarities of the initial wave and the second wave being the same; and determining that the fault generation end is the measurement end in response to the polarities of the initial wave and the second wave being opposite.

[0009] According to an embodiment of the present disclosure, the fault point of the ground wire is located by using the ground wire wave speed, the fault generation end, and the arrival times of the initial wave and the second wave, including: decoupling calculation of the ground wire wave speed according to the inductance matrix and the capacitance matrix of the UHVDC line and the ground wire; and calculating the position of the fault point from the measurement end by using the ground wire wave speed, the arrival time difference of the initial wave and the second wave according to the fault generation end.

[0010] According to an embodiment of the present disclosure, the ground wire wave speed is decoupled calculated according to the inductance matrix and the capacitance matrix of the UHVDC line and the ground wire, including: performing preliminary decoupling on the inductance matrix and the capacitance matrix by using a fourth-order Kalenbauer transformation matrix to obtain a preliminary decoupled inductance matrix and a preliminary decoupled capacitance matrix; performing row and column change operations on the preliminary decoupled inductance matrix and the preliminary decoupled capacitance matrix by using a permutation matrix to obtain a block diagonal matrix of the inductance matrix and the capacitance matrix; the block diagonal matrix includes a coupling matrix and an independent matrix; obtaining a phase-mode transformation matrix by using the product of the coupling matrix of the inductance matrix and the capacitance matrix; extracting eigenvalues by using the phase-mode transformation matrix to obtain a ground wire air mode; and calculating the ground wire wave speed by using the ground wire air mode.

[0011] A second aspect of the present disclosure provides a ground wire single-end fault location system in ice-melting operation, which can be used to implement the above-mentioned ground wire single-end fault location method in ice-melting operation, and includes: a parameter extraction module configured to extract positioning parameters of an initial wave and a second wave generated by a line fault by using traveling wave data of a measurement end; the positioning parameters include arrival times and polarities; a preliminary determination module configured to determine a fault generation end by using the polarities of the initial wave and the second wave; the fault generation end is the measurement end or a far end; and a fault location module configured to locate a fault point of a ground wire by using a ground wire wave speed, the fault generation end, and the arrival times of the initial wave and the second wave.

[0012] A third aspect of the present disclosure provides an electronic device, including: one or more processors; a memory for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors perform the above-mentioned ground wire single-end fault location method in ice-melting operation.

[0013] The fourth aspect of the present disclosure also provides a computer-readable storage medium having stored thereon executable instructions that, when executed by a processor, cause the processor to perform the method for single-ended fault location of grounding line in ice-melting operation.

[0014] According to the method for single-ended fault location of grounding line in ice-melting operation provided by the present disclosure, the data of the initial wave and the second wave are extracted from the single-ended data to locate the fault point. Since the location can be completed only by the single-ended measured data, at least part of the problem of failure of fault location caused by induced voltage interference, communication interruption and missing of data on the opposite side in the double-ended traveling wave method is solved, and the technical effect of improving the efficiency and accuracy of fault location is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A flowchart of the method for single-ended fault location of grounding line in ice-melting operation according to an embodiment of the present disclosure is schematically shown;

[0016] Figure 2 A general flowchart of the single-ended fault location scheme according to an embodiment of the present disclosure is schematically shown;

[0017] Figure 3 A traveling wave schematic diagram according to an embodiment of the present disclosure is schematically shown;

[0018] Figure 4 An equivalent circuit diagram of the UHVDC line and the grounding line according to an embodiment of the present disclosure is schematically shown;

[0019] Figure 5 An equivalent circuit of the grounding line in the de-icing process according to an embodiment of the present disclosure is schematically shown;

[0020] Figure 6 A current traveling wave diagram in the fault process according to an embodiment of the present disclosure is schematically shown;

[0021] Figure 7 A block diagram of an electronic device suitable for implementing the method for single-ended fault location of grounding line in ice-melting operation according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it will be apparent to one of ordinary skill in the art that one or more embodiments can be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques have been omitted to avoid unnecessarily obscuring the concept of the present disclosure.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the term "includes" and tautological expressions thereof, such as "including," "includes," "include," "contains," "containing," and so forth, shall be read expansively and without limitation. The terms "comprising," "comprise" and / or "comprised of," and tautological expressions thereof (e.g., "comprising of") will be understood to enable recitations that they do not exclude additional matter.

[0024] All terms used herein including technical and scientific terms have the meanings commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein are defined as having a meaning that is consistent with the context of the specification in which the terms are utilized, unless otherwise explicitly provided herein. As used herein, the term "including" and tautological expressions thereof, such as "includes," "included," and "including," shall be read expansively and without limitation.

[0025] In the case of using expressions similar to "at least one of A, B, and C, etc.", it should generally be interpreted to include at least one of each item enumerated, but not limited to only each item enumerated. In other words, it should be interpreted to mean that it includes any one of A, B, or C, or any combination of A, B, and C, etc.

[0026] The ground wire single-end fault positioning method in ice melting operation is mainly aimed at the positioning failure of the traditional double-end positioning method under the ice melting working condition due to induced voltage interference, communication interruption or missing of data on the opposite side. The background is that the insulation weakness of the ground wire may be triggered due to current transfer during DC ice melting, and the strong electromagnetic environment may cover up the fault characteristics, and the accuracy of the conventional traveling wave method or impedance method decreases sharply. The significance of the scheme is that through the single-end fault transient signal capture and adaptive filtering technology, the positioning error of the traditional double-end traveling wave method is small under the ice melting working condition due to the induced voltage interference.

[0027] Figure 1 A flowchart of a ground wire single-end fault positioning method in ice melting operation according to an embodiment of the disclosure is schematically shown, as shown in Figure 1 As shown in the figure, the embodiment of the disclosure provides a ground wire single-end fault positioning method in ice melting operation, characterized by comprising: using the traveling wave data of a measurement end to extract the positioning parameters of an initial wave and a second wave generated by a line fault; the positioning parameters include arrival time and polarity; using the polarity of the initial wave and the second wave to determine a fault generation end; the fault generation end is the measurement end or a far end; using the ground wire wave speed, the fault generation end and the arrival time of the initial wave and the second wave to locate a fault point of the ground wire.

[0028] Through the embodiment of the disclosure, the ground wire single-end indirect fault positioning in the ice melting operation of the ultra-high voltage DC transmission line is realized, not only the ice melting interruption is avoided to ensure the continuity of power supply, but also the fault detection problem in the strong interference environment is solved, the efficiency and safety of the power grid emergency repair under extreme weather are greatly improved, and key technical support is provided for the intelligent operation and inspection of the ultra-high voltage line.

[0029] On the basis of the above-mentioned embodiments, the positioning parameters of the initial wave and the second wave generated by the line fault are extracted by using the traveling wave data of the measuring end, including: obtaining the traveling wave data generated by the line fault by a Rogowski coil arranged at the capacitor between the UHV DC transmission line and the ground; extracting the arrival time of the initial wave and the second wave from the traveling wave data by using kurtosis; and extracting the polarity of the initial wave and the second wave from the traveling wave data by using a dual-tree complex wavelet transform.

[0030] According to the embodiments of the present disclosure, since the acquisition mode of the high-frequency signal in the high-voltage direct-current transmission system is completely different from that of the alternating-current transmission line, in order to obtain the traveling wave in the UHV DC transmission line, a Rogowski coil needs to be arranged at the capacitor between the UHV DC transmission line and the ground, which can transmit the high-frequency signal in the UHV DC transmission line to a high-frequency acquisition device, so as to obtain the single-end data of the fault wave.

[0031] On the basis of the above-mentioned embodiments, the arrival time of the initial wave and the second wave is extracted from the traveling wave data by using kurtosis, including: for each sampling point in the traveling wave data, the kurtosis corresponding to the sampling point is calculated by using the traveling wave data before the sampling point; the arrival time of the initial wave is determined by using the sampling point corresponding to the maximum value of the kurtosis; and the arrival time of the second wave is determined by using the sampling point corresponding to the first kurtosis maximum value after the arrival time of the initial wave.

[0032] In this embodiment, the kurtosis is defined as the normalized fourth-order central moment of the waveform, which is very sensitive to the pulse signal in the time series.

[0033]

[0034] In the formula, K is the kurtosis value of the time series x(i); n is the sampling length; μ is the average value of the time series x(i); and σ is the standard deviation of the time series x(i).

[0035] In order to describe the change of the sample series over time, the "progressive kurtosis" K(i) is proposed:

[0036]

[0037] In the formula, K(i) is the kurtosis value of the i-th signal; x(1:i) is the signal vector from the first point to the i-th point; μ is the average value of the time series x(i); and E is the expected value of the internal variable.

[0038] Wherein the arrival time t1 of the initial wave is the global kurtosis maximum point, and the expression is:

[0039]

[0040] In the formula, i is the serial number of the discrete sampling point, argmaxi is the independent variable corresponding to the maximum value of the function (here, it corresponds to i), Take 1.5 ms as the sampling interval.

[0041] The second wave arrival time t2 is the first local kurtosis maximum point (after t1), and its expression is:

[0042]

[0043] In the formula, represents the sampling serial number corresponding to the first local maximum point; is the kurtosis value sequence after t1.

[0044] Through the embodiments of the present disclosure, excessive electromagnetic noise existing in field engineering can easily make most time-frequency detection methods (such as wavelet transform) fall into a local peak state. Therefore, in order to carry out traveling wave detection, the “kurtosis” statistical index for identifying extreme values in a time sequence is selected. The progressive kurtosis can maximize the abnormal change points in the waveform and weaken irregular noise. The global maximum value of the step-by-step kurtosis represents the arrival time of the initial traveling wave, which is the first significant feature that distinguishes electromagnetic noise in a high-frequency waveform. In the subsequent step-by-step calculation, the kurtosis value gradually decreases, and the progressive kurtosis can maximize the abnormal change points in the waveform and weaken irregular noise.

[0045] On the basis of the above-mentioned embodiments, the polarity of the initial wave and the second wave is extracted from the traveling wave data by using a dual-tree complex wavelet transform, including: searching for modulus maximum points in the neighborhood of the arrival time of the initial wave and the second wave by using the dual-tree complex wavelet transform to determine the effective wave head of the traveling wave data; and determining the polarity of the initial wave and the second wave according to the effective wave head and a polarity determination rule.

[0046] Through the embodiments of the present disclosure, since the kurtosis cannot reveal the polarity of the traveling wave, and in the kurtosis curve, a local maximum point can easily appear between the initial wave and the second wave at the measurement terminal. Therefore, the dual-tree wavelet transform is selected to detect the polarity of the singular point and eliminate the redundant local maximum point. Since the first two wave peaks are identified by using the kurtosis, the polarity of the wave peaks can be derived by using the wavelet transform on the corresponding points in the original time sequence, where the initial wave polarity p1 and the second wave polarity p2.

[0047] On the basis of the above-mentioned embodiments, the polarity of the initial wave and the second wave is used to determine the fault generation end, including: in response to the polarity of the initial wave being the same as that of the second wave, determining that the fault generation end is the far end; and in response to the polarity of the initial wave being opposite to that of the second wave, determining that the fault generation end is the measurement end.

[0048] In this embodiment, the schematic diagram of the traveling wave in the DC transmission line during the deicing process is shown in FIG. 1. Figure 3 As shown in FIG. 1, when a ground fault occurs, the initial wave caused by the ground fault propagates to both ends of the ground wire, and due to electromagnetic coupling, a traveling wave also appears in the UHV DC line. On the ground wire, the terminal M connected to the rectifier and the smoothing reactor of the DC deicing device forms an open boundary to the high-frequency component due to the large inductance of the smoothing reactor; similarly, the terminal M on the UHV DC line also forms an open boundary due to the blocking of the converter. Therefore, the reflection coefficient of the high-frequency voltage traveling wave at the terminal M on the UHV DC line and the ground wire is positive, which makes the polarity of the incident wave and its reflected wave the same. However, the fault point on the ground wire forms a new boundary that is short-circuited to the ground, so the polarity of the voltage traveling wave u gM3 reflected back from the fault point is opposite to that of the incident wave. On the UHV DC line, the reflected wave generates a traveling wave whose polarity is opposite to that of u dM1 . Since the polarity of the initial wave and u gM3 is opposite, the polarity of u dM3 is also different from that of u dM1 .

[0049] The reflection and refraction wave data at the terminal M of the ground wire and the UHV DC transmission line are listed in the following Table 1 in different wave polarities.

[0050] Table 1:

[0051]

[0052] Through the embodiments of the present disclosure, in the UHV DC transmission line, different terminal conditions can cause the polarities of the reflected wave and the refracted wave to be opposite. Therefore, it can be determined from the polarity of the second wave and the polarity of the initial wave which terminal the second wave comes from. If , the fault wave comes from the refracted wave of the far end N; if , the fault wave comes from the reflected wave of the fault point.

[0053] On the basis of the above-mentioned embodiments, the fault point of the ground wire is located by using the ground wire wave speed, the fault generation end, and the arrival time of the initial wave and the second wave, including: decoupling calculation of the ground wire wave speed according to the inductance matrix and the capacitance matrix of the UHV DC line and the ground wire; and calculating the position of the fault point from the measurement end by using the ground wire wave speed, the arrival time difference of the initial wave and the second wave according to the fault generation end.

[0054] Through the embodiments of the present disclosure, the overall flowchart of the single-end fault location scheme is shown in FIG. 2. Figure 5, the time difference (t2-t1) of the initial wave and the second wave due to refraction and reflection in the fault wave is calculated, different distance formulas are used for different ends of the fault point, and the wave speed v of the fault wave on the ground wire is combined to finally obtain the fault point distance formula:

[0055]

[0056] In the formula, x f is the position of the fault point relative to the measurement end (M end), l is the total length of the transmission line, t1 is the arrival time of the initial wave, t2 is the arrival time of the second wave, and v is the wave speed on the ground wire. Ultimately, the position of the fault point on the ground wire is indirectly located through single-end data.

[0057] On the basis of the above embodiment, according to the inductance matrix and the capacitance matrix of the ultra-high voltage direct current line and the ground wire, the wave speed of the ground wire is decoupled, including: using a fourth-order Kalenbauer transformation matrix to preliminarily decouple the inductance matrix and the capacitance matrix to obtain a preliminarily decoupled inductance matrix and a preliminarily decoupled capacitance matrix; using a permutation matrix to perform row and column change operations on the preliminarily decoupled inductance matrix and the preliminarily decoupled capacitance matrix to obtain a block diagonal matrix of the inductance matrix and the capacitance matrix; the block diagonal matrix includes a coupling matrix and an independent matrix; using the product of the coupling matrix of the inductance matrix and the capacitance matrix to obtain a phase-mode transformation matrix; using the phase-mode transformation matrix to extract eigenvalues to obtain an air mode of the ground wire; and using the air mode of the ground wire to calculate the wave speed of the ground wire.

[0058] In this embodiment, a per-kilometer power frequency parameter matrix is constructed, and a phase-mode transformation matrix dedicated to the ground wire is used to obtain the propagation speed v of the obstacle wave on the ground wire. Figure 4 The equivalent circuit diagram of the ultra-high voltage direct current line and the ground wire is shown, in which the inductance matrix is L and the capacitance matrix is C.

[0059]

[0060]

[0061] In the formula, L s and C s are the self-inductance and the ground capacitance of the conductor; L sg and C sg are the self-inductance and the ground capacitance of the ground wire; L m1 is the mutual inductance between the conductors; L m is the mutual inductance between the conductors and the ground wire; L mg is the mutual inductance between the ground wires; C m1 is the coupling capacitance between the conductors; C m is the coupling capacitance between the conductors and the ground wire; and C mg is the coupling capacitance between the ground wires.

[0062] The voltage and current fluctuation equation of the lossless multi-conductor transmission line is:

[0063]

[0064]

[0065] where U and I are column vectors of voltage and current flowing through the multi-conductor transmission line with ground wires, respectively, which are dl u d2 u gl u g2 ] -1 ,I=[i a1 i a2 i g1 i g2 ] -1 which are functions of the distance x and time t along the line.

[0066] Combining the wave equations of voltage and current of the lossless multi-conductor transmission line, we have

[0067]

[0068]

[0069] where L and C are full rank matrices, because of the electromagnetic coupling between the four lines. The basic method to simplify the multi-conductor transmission line is to transform L and C into diagonal matrices, so that the wave equations of the same phase become independent equations.

[0070] Because of the differences in structural parameters and voltage levels between UHVDC transmission lines and ground wires, the decoupling method is very different from that of ordinary double-circuit lines. In the following, the same fourth-order Kalenbauer transformation matrix P as the phase mode transformation of ordinary double-circuit lines is used for initial decoupling:

[0071]

[0072] According to the P -1 LPand P -1 CPformula, the simplified inductance parameter matrix L1 and capacitance parameter matrix C1 can be calculated. And through the basic change operation of matrix B , where B is:

[0073]

[0074]

[0075] where, L z1 and Cz1 L is the wire-to-ground coupling matrix z2 and C z2 are independent matrices.

[0076] Since the "coupling" operation is independent, for the convenience of subsequent derivation, K1 and K2 can be obtained by the following way:

[0077]

[0078] Since K1 and K2 are asymmetric matrices, their diagonal matrices must be obtained by numerical calculation. Assuming that the phase mode conversion matrices of K1 and K2 are F and T, respectively, the corresponding diagonal matrices are K 1∧ and K 2∧ :

[0079]

[0080] In order to completely separate LC and CL, using F1 and T1, define the transformation matrix S of LC, and define the transformation matrix Q of CL:

[0081]

[0082]

[0083] According to the above conversion formula, we can obtain the diagonal matrices ∧ u and ∧ i , whose diagonal elements are the eigenvalues of LC and CL, respectively.

[0084]

[0085] The above diagonal matrices ∧ u and ∧ i are matched, because they have the same physical definition. Although the above inference is based on lossless line, resistance does not affect permeability and dielectric constant, which determine inductance and capacitance. Considering that the wave speed can be calculated by the inductance and capacitance of the conductor, the wave speed of the ground wire (ground wire air mode) can be expressed as:

[0086]

[0087] Through the embodiments of the present disclosure, the wave speed is a key factor for the traveling wave fault location, and accurate wave speed is required for accurate positioning. Due to the difference between the main parameters of the ground wire and the ultra-high voltage direct current line, the wave speed changes; when calculating the wave speed of the ground wire, it must be decoupled, and because the phase mode conversion of the multi-conductor system in the deicing process is different from the conventional method, a lossless transmission line is used to obtain different mode speeds.

[0088] Case:

[0089] Figure 2 The overall flow chart of the single-end fault location scheme according to an embodiment of the present disclosure is schematically shown in FIG. 1. Figure 2 The present embodiment is simulated by EMTDC. The DC de-icing device is connected to the grounding wire, while in the simulation, the UHV DC line is disconnected from the converter, Figure 6 The equivalent circuit of the grounding wire during the de-icing process is shown in FIG. 2. Figure 6 The current traveling wave diagram during the fault process is shown in FIG. 3. Taking a 800 kV UHV DC transmission line in a certain place as an example, the parameters of the DC de-icing device are listed in Table 2 (DC de-icing device parameters).

[0090] Table 2:

[0091]

[0092] On the one hand, although the electromagnetic noise can cause abnormal singular points of the traveling wave in Figure 6 but the kurtosis can clearly highlight the initial wave and the second wave. On the other hand, the maximum value of the wavelet modulus can mark the polarity of the traveling wave. By comparing the polarity of the initial wave and the second wave, the second wave can be identified as the reflected wave from the fault point. The results are listed in Table 3 (traveling wave polarity).

[0093] Table 3:

[0094]

[0095] Construct the power frequency parameter matrix per kilometer:

[0096]

[0097]

[0098] The conversion matrix S and Q thereof are obtained as follows:

[0099]

[0100]

[0101] The diagonal matrix thereof is finally obtained as follows:

[0102]

[0103] The = 0.1153, = 0.1148, it can be inferred that the wave speed of the grounding wire (grounding wire air mode) is almost the same as that of the DC conductor air mode, and the error is not more than 0.2%, at this time m / s

[0104] According to the formula of single-ended traveling wave fault location, the calculated fault point is 100.128 kilometers away from terminal M (the actual fault point is located at 100 kilometers), 445.872 kilometers away from terminal N, the fault point deviation is 128 meters, and the error is 0.023%.

[0105] Based on the above ground wire single-ended fault location method in ice-melting operation, the disclosure provides a ground wire single-ended fault location system in ice-melting operation, which can be used to implement the above ground wire single-ended fault location method in ice-melting operation, comprising: a parameter extraction module, configured to extract the positioning parameters of the initial wave and the second wave generated by the line fault by using the traveling wave data of the measurement end; the positioning parameters include the arrival time and the polarity; a preliminary determination module, configured to determine the fault generation end by using the polarity of the initial wave and the second wave; the fault generation end is the measurement end or the far end; and a fault location module, configured to locate the fault point of the ground wire by using the ground wire wave speed, the fault generation end, and the arrival time of the initial wave and the second wave.

[0106] Figure 7 A block diagram of an electronic device suitable for implementing the ground wire single-ended fault location method in ice-melting operation according to an embodiment of the disclosure is schematically shown.

[0107] As shown in Figure 7 The electronic device 700 according to an embodiment of the disclosure includes a processor 701, which can perform various appropriate actions and processes according to programs stored in a read-only memory (ROM) 702 or loaded into a random access memory (RAM) 703 from a storage portion 708. The processor 701 can include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor, and / or a related chipset, and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), and the like. The processor 701 can also include an on-board memory for cache use. The processor 701 can include a single processing unit or a plurality of processing units for performing different actions of the method processes according to embodiments of the disclosure.

[0108] In the RAM 703, various programs and data required for the operation of the electronic device 700 are stored. The processor 701, the ROM 702, and the RAM 703 are connected to each other through a bus 704. The processor 701 performs various operations of the method processes according to embodiments of the disclosure by executing the programs in the ROM 702 and / or the RAM 703. It should be noted that the programs can also be stored in one or more memories other than the ROM 702 and the RAM 703. The processor 701 can also perform various operations of the method processes according to embodiments of the disclosure by executing the programs stored in the one or more memories.

[0109] According to an embodiment of the present disclosure, the electronic device 700 can further include an input / output (I / O) interface 705 also connected to the bus 704. The electronic device 700 can further include one or more of the following components connected to the I / O interface 705: an input part 706 including a keyboard, a mouse, etc.; an output part 707 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage part 708 including a hard disk, etc.; and a communication part 709 including a network interface card such as a LAN card, a modem, etc. The communication part 709 performs communication processing via a network such as the Internet. A drive 700 is also connected to the I / O interface 705 as necessary. A removable medium 701 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc. is mounted on the drive 700 as necessary, so that a computer program read out therefrom is installed in the storage part 708 as necessary.

[0110] The present disclosure also provides a computer readable storage medium, which can be included in the device / apparatus / system described in the above embodiments, or can exist separately without being assembled into the device / apparatus / system. The above computer readable storage medium carries one or more programs, which when executed, implement the method according to the embodiments of the present disclosure.

[0111] According to an embodiment of the present disclosure, the computer readable storage medium can be a non-volatile computer readable storage medium, which can include, but is not limited to, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any appropriate combination thereof. In the present disclosure, the computer readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device. For example, according to an embodiment of the present disclosure, the computer readable storage medium can include the ROM 702 and / or the RAM 703 described above, and / or one or more memory other than the ROM 702 and the RAM 703.

[0112] The embodiments of the present disclosure also include a computer program product, which includes a computer program containing program codes for executing the methods shown in the flowcharts. When the computer program product is run in a computer system, the program codes are used to make the computer system implement the methods provided by the embodiments of the present disclosure.

[0113] The above-described functions of the system / device defined in the system / apparatus of the embodiments of the present disclosure are performed when the computer program is executed by the processor 701. According to the embodiments of the present disclosure, the system, apparatus, module, unit, etc. described above can be implemented by the computer program modules.

[0114] In one embodiment, the computer program can be stored in a tangible storage medium, such as an optical, magnetic, or other memory on a server, computer, or other computing device. In another embodiment, the computer program can be transmitted over a network, including the Internet, WAN, LAN, or other network, including a wireless network, between a server and a client (e.g., using a web server or other server) or between two client devices (e.g., using a peer-to-peer network), using signal(s) in the form of packets, electronic signals, electrical, optical, or other form.

[0115] In such an embodiment, the computer program can be downloaded and installed from a network, such as the Internet, WAN, LAN, or other network, including a wireless network, between a server and a client (e.g., using a web server or other server) or between two client devices (e.g., using a peer-to-peer network), using signal(s) in the form of packets, electronic signals, electrical, optical, or other form. The computer program, when executed by the processor 701, performs the above-described functions of the system defined in the embodiments of the present disclosure. According to the embodiments of the present disclosure, the system, apparatus, device, module, unit, etc. described above can be implemented by the computer program modules.

[0116] According to the embodiments of the present disclosure, the program code for execution of the computer programs provided by the embodiments of the present disclosure can be written in any combination of one or more programming languages, and specifically, can be implemented using high-level procedural and / or object-oriented programming language, and / or assembly / machine language. The programming language includes, but is not limited to, such as Java, C++, python, “C” language, or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on a remote computing device, or entirely on a remote computing device or server. In the case involving a remote computing device, the remote computing device can be connected to the user computing device through any kind of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0117] The computer program product of the first aspect can include one or more non-transitory computer-readable media storing instructions that, when executed, cause one or more processors to perform the operations of the first aspect. The one or more non-transitory computer-readable media can include, for example, magnetic media such as one or more magnetic disks, magnetic tapes or cassettes; optical media such as one or more compact discs (CD), optical discs or discs (for example, DVD, Blu-ray Disc®, digital video disc, ultra density disc, ultra-compact disc, any optical media, etc.); semiconductor media such as solid state hard drives (for example, flash memory, solid state USB drives, etc.); any other suitable medium; or any suitable combination of media.

[0118] Those skilled in the art will understand that features of the various embodiments and / or claims of the present disclosure can be combined or / and integrated with one another, even though such a combination or integration is not expressly disclosed in the present disclosure. In particular, the features of the various embodiments and / or claims of the present disclosure can be combined and / or integrated with one another in any number of ways, without departing from the spirit and scope of the present disclosure. All such combinations and / or integrations are within the scope of the present disclosure.

[0119] The above describes the embodiments of the present disclosure. However, these embodiments are merely for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although the above describes each embodiment separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present disclosure is defined by the appended claims and their equivalents. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present disclosure, and all such substitutions and modifications shall fall within the scope of the present disclosure.

Claims

1. A method for locating a single-ended ground wire fault during ice melting operations, characterized in that: include: Using the traveling wave data at the measuring end, extracting the location parameters of the initial wave and the secondary wave generated by the line fault; the location parameters include arrival time and polarity; Determine the fault-generating end by using the polarity of the initial wave and the second wave; the fault-generating end is the measuring end or the remote end; The fault point of the ground wire is located by using the ground wire wave speed, the fault generating end, and the arrival time of the initial wave and the second wave.

2. The method according to claim 1, wherein The method of extracting the positioning parameters of the initial wave and the second wave generated by the line fault by using the traveling wave data at the measuring end includes: The traveling wave data generated by the line fault is obtained by installing a Rogowski coil at the capacitor between the UHVDC transmission line and the ground; Using kurtosis, the arrival times of the initial and second waves are extracted from the traveling wave data; The polarities of the initial and secondary waves are extracted from the traveling wave data using the dual-tree complex wavelet transform.

3. The method according to claim 2, wherein: The method of extracting the arrival times of the initial wave and the second wave from the traveling wave data by using the kurtosis includes: For each sampling point in the traveling wave data, the kurtosis corresponding to the sampling point is calculated using the traveling wave data before the sampling point; The arrival time of the initial wave is determined using the sampling point corresponding to the maximum value of the kurtosis; The arrival time of the second wave is determined by using the sampling point corresponding to the first kurtosis maximum after the arrival time of the initial wave.

4. The method according to claim 2, wherein: The method of extracting the polarity of the initial wave and the second wave from the traveling wave data by using the dual-tree complex wavelet transform comprises: The effective wave head of the traveling wave data is determined by searching for the modulus maximum point in the neighborhood near the arrival time of the initial wave and the second wave through the dual-tree complex wavelet transform. Determine the polarity of the initial wave and the second wave based on the effective wave head and polarity judgment rules.

5. The method according to claim 1, wherein The method of determining the fault generating end by using the polarity of the initial wave and the second wave includes: In response to the polarity of the initial wave and the second wave being the same, it is determined that the fault-generating end is the far end; In response to the polarity of the initial wave being opposite to that of the second wave, the fault-generating end is determined to be the measuring end.

6. The method according to claim 1, wherein The method of locating the fault point of the ground line by utilizing the ground line wave velocity, the fault generating end, and the arrival time of the initial wave and the second wave includes: According to the inductance matrix and capacitance matrix of UHVDC line and ground wire, decoupling and calculation of ground wire wave velocity are performed; According to the fault generating end, the distance between the fault point and the measuring end is calculated by using the ground line wave velocity and the arrival time difference between the initial wave and the second wave.

7. The method according to claim 6, wherein: The decoupling and calculating of the ground line wave velocity according to the inductance matrix and the capacitance matrix of the UHVDC line and the ground line includes: The inductance matrix and the capacitance matrix are preliminarily decoupled using the fourth-order Karenbauer transformation matrix to obtain the preliminarily decoupled inductance matrix and capacitance matrix. Using a permutation matrix to perform row and column transformation operations on the preliminarily decoupled inductance matrix and capacitance matrix, thereby obtaining block diagonal matrices of the inductance matrix and capacitance matrix; the block diagonal matrices include a coupling matrix and an independent matrix; The phase mode transformation matrix is ​​obtained by multiplying the coupling matrix of the inductance matrix and the capacitance matrix; The phase mode transformation matrix is ​​used to extract the eigenvalues ​​and obtain the ground-air mode; The ground line wave velocity is calculated using the ground line air model.

8. A system for locating a single-ended ground wire fault during an ice-melting operation, the system being capable of implementing the method for locating a single-ended ground wire fault during an ice-melting operation as claimed in any one of claims 1 to 7, the system comprising: A parameter extraction module is used to extract the positioning parameters of the initial wave and the second wave generated by the line fault using the traveling wave data at the measurement end; The positioning parameters include arrival time and polarity; A preliminary determination module is used to determine the fault generating end by using the polarity of the initial wave and the second wave; the fault generating end is the measuring end or the remote end; The fault location module is used to locate the fault point of the ground line by using the ground line wave speed, the fault generating end, and the arrival time of the initial wave and the second wave.

9. An electronic device comprising: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors are enabled to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having executable instructions stored thereon, which, when executed by a processor, causes the processor to perform the method according to any one of claims 1 to 7.

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