GIL fault location method and system based on combination of SVMD and TEO

Abstract

The invention discloses a GIL fault distance measurement method and system based on combination of SVMD and TEO, and relates to the technical field of power system relay protection, and the method comprises the following steps: collecting three-phase current data at the head and tail ends of a GIL, and carrying out the calculation, and obtaining a current traveling wave line mode component; the current traveling wave line mode component is processed, and the maximum mode component is selected; the maximum modal component is calculated through TEO, the arrival time of wave heads at the head end and the tail end of the GIL is calibrated, and the traveling wave velocity is calculated; and calculating the fault distance of the fault point, and detecting the fault point. When the GIL breaks down, the arrival moments of wave heads at the head end and the tail end are calibrated by adopting an SVMD and TEO combined mode for current traveling wave line mode components at the head end and the tail end, then the fault distance is calculated, and the fault distance is calculated by combining the calculated detection results of gas decomposition products of a gas chamber where a fault point is located and gas decomposition products of a front gas chamber and a rear gas chamber. And further determining the air chamber where the fault exists.

Description

Technical Field

[0001] The present invention relates to the technical field of power system relay protection, and in particular to a GIL fault distance measurement method and system based on the combination of SVMD and TEO. Background Art

[0002] GIL is a high-voltage, high-current, long-distance power transmission equipment that uses SF6, SF6 / N2 or other gas insulation, and the shell and conductor are coaxially arranged. It has significant advantages such as large transmission capacity, small transmission loss, small footprint, low operating cost, environmental friendliness, and high safety. GIL usually operates under high voltage and high current conditions. Once it fails, the transmission of electric energy cannot be completed, and it has a huge impact on the stability of the system, thereby causing great economic losses. Accurately measuring the distance of GIL faults is of great significance to shortening the system's downtime, reducing economic losses, and improving the system's power supply reliability. Existing GIL fault distance measurement methods mainly include fault distance measurement methods based on ultrasonic detection, fault distance measurement methods based on ultra-high frequency, fault distance measurement methods based on vibration, fault distance measurement methods based on traveling waves, and fault distance measurement methods based on chemical detection. However, each method has the following disadvantages:

[0003] 1) The disadvantage of the fault distance measurement method based on ultrasonic detection is that the arrangement of the sensors and the transmission attenuation characteristics of ultrasonic waves on the GIL have a great influence on the ranging accuracy.

[0004] 2) The disadvantage of the UHF-based fault distance measurement method is that this type of method requires the installation of sensors, but the number of hand holes within a unit distance of the GIL is limited, resulting in too few installation locations for built-in sensors.

[0005] 3) The disadvantage of the vibration-based fault distance measurement method is that the GIL is a fully enclosed structure, and the existing external detection method is not sensitive enough to detect internal defects and cannot accurately locate the fault.

[0006] 4) The disadvantage of the fault distance measurement method based on traveling waves is that high-precision distance measurement requires precise calibration of the wave head arrival time.

[0007] 5) The disadvantage of the fault distance measurement method based on chemical detection is that this type of method can only perform qualitative monitoring on whether the GIL has an internal breakdown fault, but cannot determine the exact location of the fault point. Summary of the invention

[0008] In view of the problems existing in the existing GIL fault distance measurement and system based on the combination of SVMD and TEO, the present invention is proposed.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0010] In a first aspect, an embodiment of the present invention provides a GIL fault location method based on a combination of SVMD and TEO, which comprises the following steps:

[0011] Collect the three-phase current data at both ends of the GIL, and perform calculations to obtain the line mode components of the current traveling wave;

[0012] Process the line mode components of the current traveling wave and select the largest modal component;

[0013] The largest modal component is calculated through TEO, the arrival time of the wave head at the first and last ends of the GIL is calibrated, and the traveling wave velocity is calculated;

[0014] Calculate the fault distance of the fault point and detect the fault point.

[0015] As a preferred solution of the GIL fault location method based on the combination of SVMD and TEO described in the present invention, the formula of the GIL head-end current traveling wave line mode component is expressed as follows:

[0016] i Sα (n)=[i SA (n)-i SB (n)] / 3;

[0017] In the formula, i SA (n), i SB (n) are the A and B phase currents collected at the head end of the GIL; i Sα (n) is the line mode component of the current traveling wave at the head end of the GIL; n is the signal collection point;

[0018] Among them, the formula of the traveling wave line mode component of the GIL end current is expressed as:

[0019] i Mα (n)=[i MA (n)-i MB (n)] / 3;

[0020] In the formula, i MA (n), i MB (n) are the A and B phase currents collected at the GIL end; i Mα (n) is the line mode component of the traveling wave current at the end of the GIL.

[0021] As a preferred solution of the GIL fault location method based on the combination of SVMD and TEO described in the present invention, the processing of the current traveling wave line mode component includes decomposing the GIL head end current traveling wave line mode component by using SVMD, wherein the decomposition formula is expressed as:

[0022]

[0023] In the formula, i LSαIMF (n) is i Sα (n) The Lth modal component obtained by decomposition, i Su (n) is the unprocessed part, is the sum of other modal components obtained previously;

[0024] The line mode component of the GIL terminal current traveling wave is decomposed using SVMD, and the formula is expressed as follows:

[0025]

[0026] Where: i LMαIMF (n) is i Mα (n) The Lth modal component obtained by decomposition, i Mu (n) is the unprocessed part, is the sum of the other modal components obtained previously.

[0027] As a preferred solution of the GIL fault location method based on the combination of SVMD and TEO described in the present invention, the processing of the current traveling wave line mode component also includes calculating the peak factors of the multiple modal components obtained by decomposition, wherein the peak factor calculation formula of the multiple modal components is expressed as:

[0028]

[0029] In the formula, p h1S is the hth modal component i of the current traveling wave at the first end hSαIMF The peak value of (n), p h2S is the hth modal component i of the current traveling wave at the first end hSαIMF (n), where N is the number of sampling points, CF hS is the hth modal component i of the current traveling wave at the first end hSαIMF (n) crest factor;

[0030] The largest modal component at the head of the GIL is selected through the calculation results and recorded as

[0031] When calculating the peak factor for the GIL end, the formula is expressed as:

[0032]

[0033] In the formula, p h1M is the hth modal component i of the terminal current traveling wave hMαIMF The peak value of (n), p h2M is the hth modal component i of the terminal current traveling wave hMαIMF The root mean square value of (n), CF hM is the hth modal component i of the terminal current traveling wave hMαIMF(n) crest factor;

[0034] The largest modal component at the end of the GIL is selected from the calculation results and recorded as

[0035] As a preferred solution of the GIL fault location method based on the combination of SVMD and TEO described in the present invention, wherein: The TEO of the wave head at the first and last ends is used to calibrate the arrival time of the wave head at the first and last ends. The calculation formula of TEO is:

[0036]

[0037] In the formula, for TEO;

[0038]

[0039] In the formula, for TEO.

[0040] As a preferred solution of the GIL fault location method based on the combination of SVMD and TEO described in the present invention, the calculation formula of the traveling wave velocity is:

[0041]

[0042] Where, L is the inductance per unit length of GIL; C is the capacitance per unit length of GIL;

[0043] The fault distance is calculated by the double-terminal traveling wave fault distance measurement formula. The calculation formula is:

[0044]

[0045] Where l is the length of GIL; d fS is the distance between the fault point and the head end.

[0046] As a preferred solution of the GIL fault distance measurement method based on the combination of SVMD and TEO described in the present invention, the method for detecting the fault point includes:

[0047] When the SO2 gas concentration is less than or equal to 1μL / L, the evaluation result is normal;

[0048] When the SO2 gas concentration is 1-5 μL / L, the detection cycle is shortened;

[0049] When the SO2 gas concentration is 5-10μL / L, follow-up detection and comprehensive diagnosis are carried out;

[0050] When the SO2 gas concentration is greater than 10μL / L, a comprehensive diagnosis is performed;

[0051] When the H2S gas concentration is less than or equal to 1μL / L, the evaluation result is normal;

[0052] When the H2S gas concentration is 1-2μL / L, follow-up detection and comprehensive diagnosis are performed;

[0053] When the H2S gas concentration is greater than 5μL / L, a comprehensive diagnosis is performed.

[0054] In a second aspect, an embodiment of the present invention provides a GIL fault distance measurement system based on a combination of SVMD and TEO, which includes an acquisition module, a calculation module, and an analysis module;

[0055] The acquisition module is used to collect three-phase current data at both ends of the GIL;

[0056] The calculation module is used to calculate the three-phase current data and process the current traveling wave line mode component;

[0057] The analysis module is used to detect the fault point.

[0058] In a third aspect, an embodiment of the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, any step of the above-mentioned GIL fault distance measurement method based on the combination of SVMD and TEO is implemented.

[0059] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the above-mentioned GIL fault distance measurement method based on the combination of SVMD and TEO is implemented.

[0060] The beneficial effects of the present invention are as follows: when a GIL fails, the arrival time of the wave heads at the two ends is calibrated by combining the SVMD and TEO methods for the current traveling wave line mode components at the two ends, and then the fault distance is calculated. Combined with the calculated detection results of the gas decomposition products of the air chamber where the fault point is located and the air chambers before and after it, the air chamber where the fault is located is further determined, which can shorten the system downtime, reduce economic losses, and improve the power supply reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0062] Figure 1 It is a flow chart of the GIL fault location method based on the combination of SVMD and TEO.

[0063] Figure 2 This is a schematic diagram of the topological structure of the hydropower plant system provided in Example 1.

[0064] Figure 3 This is a result diagram of multiple modal components obtained by decomposing the line mode current at the S1 end after the SVMD algorithm is used when a 30Ω transition resistor fault occurs at the A phase head end 150m of L1 in Example 1.

[0065] Figure 4 This is a result diagram of multiple modal components obtained after the line mode current at the M1 end is decomposed by the SVMD algorithm when a 30Ω transition resistor fault occurs at 150m from the first end of the A phase of L1 in Example 1.

[0066] Figure 5 This is a calibration result diagram of the moment when the traveling wave reaches the S1 end when a 30Ω transition resistor fault occurs at 150m from the first end of phase A of L1 in Example 1.

[0067] Figure 6 This is a calibration result diagram of the moment when the traveling wave reaches the M1 terminal when a 30Ω transition resistor fault occurs at 150m from the first end of phase A of L1 in Example 1. DETAILED DESCRIPTION

[0068] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0069] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0070] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0071] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0072] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0073] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] Example 1

[0075] Reference Figure 1 to Figure 6 , which is the first embodiment of the present invention, provides a GIL fault location method based on the combination of SVMD and TEO, comprising the following steps:

[0076] S1. Collect the three-phase current data at both ends of the GIL, and calculate to obtain the line mode component of the current traveling wave.

[0077] The formula for the traveling wave line mode component of the GIL head-end current is expressed as:

[0078] i Sα (n)=[i SA (n)-i SB (n)] / 3;

[0079] In the formula, i SA (n), i SB(n) are the A and B phase currents collected at the head end of the GIL; i Sα (n) is the line mode component of the current traveling wave at the head end of the GIL; n is the signal collection point;

[0080] Among them, the formula of the traveling wave line mode component of the GIL end current is expressed as:

[0081] i Mα (n)=[i MA (n)-i MB (n)] / 3;

[0082] In the formula, i MA (n), i MB (n) are the A and B phase currents collected at the GIL end; i Mα (n) is the line mode component of the traveling wave current at the end of the GIL.

[0083] In this embodiment, PSCAD / EMTDC is used to Figure 2 The hydropower plant system topology shown in the figure is simulated. L1~L4 are four GIL outgoing lines. The length of L1 is 494.17m, the length of L2 is 594.6m, the length of L3 is 539.82m, and the length of L4 is 518.98m. The parameter of GIL inductance L is 0.205mH / m, and the parameter of capacitance C is 54.23pF / m. The parameters of generator sets 1 to 4 are the same, and the effective value of the line voltage is 525kV. S1~S4 are the current transformers on the near generator side of L1~L4, respectively, and M1~M4 are the current transformers on the far generator side of L1~L4, respectively, and the sampling frequency is 0.5MHz;

[0084] When the fault occurs at 2.5s, 150m away from the first end of phase A of L1, the transition resistance is 30Ω, and the three-phase current i at the S1 end 8ms before and 24ms after the fault is extracted. SA (n), i SB (n), i SC (n) and the three-phase current i at the M1 terminal MA (n), i MB (n), i MC (n), the traveling wave line mode components of the current at the S1 and M1 terminals of L1 are used as an example to illustrate the calculation process:

[0085] The current traveling wave line mode component at the S1 end: i Sα (n)=[i SA (n)-i SB (n)] / 3;

[0086] The current traveling wave line mode component at the M1 end: i Mα (n)=[i MA (n)-iMB (n)] / 3.

[0087] S2. Process the line mode components of the current traveling wave and select the largest modal component.

[0088] Processing the current traveling wave line mode component includes decomposing the GIL head end current traveling wave line mode component using SVMD, wherein the decomposition formula is expressed as:

[0089]

[0090] In the formula, i LSαIMF (n) is i Sα (n) The Lth modal component obtained by decomposition, i Su (n) is the unprocessed part, is the sum of other modal components obtained previously;

[0091] The line mode component of the GIL terminal current traveling wave is decomposed using SVMD, and the formula is expressed as follows:

[0092]

[0093] Where: i LMαIMF (n) is i Mα (n) The Lth modal component obtained by decomposition, i Mu (n) is the unprocessed part, is the sum of the other modal components obtained previously.

[0094] The SVMD is further used to decompose the current traveling wave line mode components at the ends of the GIL, and the forms including multiple modal components shown in equations (3) and (4) are obtained. The multiple modal components obtained by SVMD decomposition of the current traveling wave line mode components at the S1 and M1 ends of L1 are used as an example to illustrate the calculation process;

[0095] Multiple modal components at S1:

[0096] Multiple modal components at the M1 end:

[0097] The multiple modal component result diagrams obtained after the line mode current at the S1 end and the M1 end is decomposed by the SVMD algorithm are shown as follows: Figure 3 and Figure 4 shown.

[0098] Processing the current traveling wave line mode component also includes calculating the peak factors of the multiple modal components obtained by decomposition, wherein the peak factor calculation formula of the multiple modal components is expressed as:

[0099]

[0100] In the formula, p h1S is the hth modal component i of the current traveling wave at the first end hSαIMF The peak value of (n), p h2S is the hth modal component i of the current traveling wave at the first end hSαIMF (n), where N is the number of sampling points, CF hS is the hth modal component i of the current traveling wave at the first end hSαIMF (n) crest factor;

[0101] The largest modal component at the head of the GIL is selected through the calculation results and recorded as

[0102] When calculating the peak factor for the GIL end, the formula is expressed as:

[0103]

[0104] In the formula, p h1M is the hth modal component i of the terminal current traveling wave hMαIMF The peak value of (n), p h2M is the hth modal component i of the terminal current traveling wave hMαIMF The root mean square value of (n), CF hM is the hth modal component i of the terminal current traveling wave hMαIMF (n) crest factor;

[0105] The largest modal component at the end of the GIL is selected from the calculation results and recorded as

[0106] In this embodiment, the calculated maximum peak factor of the first-end modal component is CF 4S =86.8485, the maximum peak factor of the terminal modal component is CF 4M =98.6655, the calculation process is:

[0107] First-end peak factor:

[0108] Take modal component 4 as an example to calculate:

[0109] The calculation process of the remaining modal components is the same as that of modal component 4, and the calculation results are CF 1S =35.0270, CF 2S =46.5166, CF 3S =69.8853;

[0110] Because CF 4S The maximum value, so is modal component 4.

[0111] Terminal crest factor:

[0112] Take modal component 4 as an example to calculate:

[0113] The calculation process of the modal component is the same as that of modal component 4, and the calculation result is CF 1M =33.7233, CF 2M =58.9747, CF 3M =68.7472;

[0114] Due to CF 4M is the maximum value, so is modal component 4.

[0115] S3. Calculate the largest modal component through TEO, calibrate the arrival time of the wave head at the first and last ends of the GIL, and calculate the traveling wave velocity.

[0116] calculate The TEO of the wave head at the first and last ends is used to calibrate the arrival time of the wave head at the first and last ends. The calculation formula of TEO is:

[0117]

[0118] In the formula, for TEO;

[0119]

[0120] In the formula, for TEO.

[0121] In the embodiment, calculation and Energy operator and And and The horizontal coordinate at the maximum peak value is calibrated, and the calibration result is t S =2.50802s, t M =2.50805s, the calculation process is as follows:

[0122]

[0123] The calibration results of the horizontal coordinates at the maximum peak of the energy operator at the S1 end and the M1 end are shown in the figure below. Figure 5 and Figure 6 shown.

[0124] The calculation formula of the traveling wave velocity is:

[0125]

[0126] Where, L is the inductance per unit length of GIL; C is the capacitance per unit length of GIL;

[0127] The fault distance is calculated by the double-terminal traveling wave fault distance measurement formula. The calculation formula is:

[0128]

[0129] Where l is the length of GIL; d fS is the distance between the fault point and the head end.

[0130] In the embodiment, the calculation result is v=9.484255984×10 6 m / s, the calculation process is as follows:

[0131] Traveling wave speed:

[0132] Calculate the fault distance, the result is d fS =154.82m, the calculation process is as follows:

[0133] Fault distance:

[0134]

[0135] Therefore, the fault distance calculated using traveling waves is 154.82m.

[0136] S4. Calculate the fault distance of the fault point and detect the fault point.

[0137] Methods for detecting fault points include:

[0138] When the SO2 gas concentration is less than or equal to 1μL / L, the evaluation result is normal;

[0139] When the SO2 gas concentration is 1-5 μL / L, the detection cycle is shortened;

[0140] When the SO2 gas concentration is 5-10μL / L, follow-up detection and comprehensive diagnosis are carried out;

[0141] When the SO2 gas concentration is greater than 10μL / L, a comprehensive diagnosis is performed;

[0142] When the H2S gas concentration is less than or equal to 1μL / L, the evaluation result is normal;

[0143] When the H2S gas concentration is 1-2μL / L, follow-up detection and comprehensive diagnosis are performed;

[0144] When the H2S gas concentration is greater than 5μL / L, a comprehensive diagnosis is performed.

[0145] The gas decomposition products of the air chamber where the fault point is located and the air chambers before and after it are tested, and the air chamber with abnormal test results is determined as the faulty air chamber.

[0146] In summary, when a GIL fails, the arrival time of the wave heads at the two ends is calibrated by combining SVMD and TEO for the line mode components of the current traveling wave at the two ends, and then the fault distance is calculated. Combined with the detection results of the gas decomposition products of the gas chamber where the fault point is located and the gas chambers before and after it, the gas chamber where the fault is located is further determined, which can shorten the system downtime, reduce economic losses, and improve the power supply reliability of the system.

[0147] Example 2

[0148] On the basis of the first embodiment, this embodiment further provides a GIL fault distance measurement system based on the combination of SVMD and TEO, including a collection module, a calculation module, and an analysis module;

[0149] The acquisition module is used to collect three-phase current data at both ends of the GIL;

[0150] The calculation module is used to calculate the three-phase current data and process the current traveling wave line mode component;

[0151] The analysis module is used to detect the fault point.

[0152] This embodiment also provides a computer device, which is suitable for the GIL fault distance measurement method based on the combination of SVMD and TEO, including a memory and a processor; the memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions to implement the GIL fault distance measurement method based on the combination of SVMD and TEO as proposed in the above embodiment.

[0153] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0154] This embodiment further provides a storage medium on which a computer program is stored. When the program is executed by a processor, the GIL fault distance measurement method based on the combination of SVMD and TEO as proposed in the above embodiment is implemented.

[0155] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0156] 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A GIL fault location method based on the combination of SVMD and TEO, characterized in that: The following steps are included: Collect the three-phase current data at both ends of the GIL, and perform calculations to obtain the line mode components of the current traveling wave; Process the line mode components of the current traveling wave and select the largest modal component; The largest modal component is calculated through TEO, the arrival time of the wave head at the first and last ends of the GIL is calibrated, and the speed of the traveling wave is calculated; Calculate the fault distance of the fault point and detect the fault point.

2. The GIL fault location method based on the combination of SVMD and TEO as claimed in claim 1, characterized in that: The formula for the traveling wave line mode component of the GIL head-end current is expressed as: i Sα (n)=[i SA (n)-i SB (n)] / 3; In the formula, i SA (n), i SB (n) are the A and B phase currents collected at the head end of the GIL; i Sα (n) is the line mode component of the current traveling wave at the head end of the GIL; n is the signal collection point; Among them, the formula of the traveling wave line mode component of the GIL end current is expressed as: i Mα (n)=[i MA (n)-i MB (n)] / 3; In the formula, i MA (n), i MB (n) are the A and B phase currents collected at the GIL end; i Mα (n) is the line mode component of the traveling wave current at the end of the GIL.

3. The GIL fault location method based on the combination of SVMD and TEO as claimed in claim 2, characterized in that: Processing the current traveling wave line mode component includes decomposing the GIL head end current traveling wave line mode component using SVMD, wherein the decomposition formula is expressed as: In the formula, i LSαIMF (n) is i Sα (n) The Lth modal component obtained by decomposition, i Su (n) is the unprocessed part, is the sum of other modal components obtained previously; The line mode component of the GIL terminal current traveling wave is decomposed using SVMD, and the formula is expressed as follows: Where: i LMαIMF (n) is i Mα (n) The Lth modal component obtained by decomposition, i Mu (n) is the unprocessed part, is the sum of the other modal components obtained previously.

4. The GIL fault location method based on the combination of SVMD and TEO as claimed in claim 3, characterized in that: Processing the line mode component of the current traveling wave also includes calculating the peak factors of the multiple modal components obtained by decomposition, wherein the calculation formula of the peak factors of the multiple modal components is expressed as: In the formula, p h1S is the hth modal component i of the current traveling wave at the first end hSαIMF The peak value of (n), p h2S is the hth modal component i of the current traveling wave at the first end hSαIMF (n), where N is the number of sampling points, CF hS is the hth modal component i of the current traveling wave at the first end hSαIMF (n) crest factor; The largest modal component at the head of the GIL is selected through the calculation results and recorded as When calculating the peak factor for the GIL end, the formula is expressed as: In the formula, p h1M is the hth modal component i of the terminal current traveling wave hMαIMF The peak value of (n), p h2M is the hth modal component i of the terminal current traveling wave hMαIMF The root mean square value of (n), CF hM is the hth modal component i of the terminal current traveling wave hMαIMF (n) crest factor; The largest modal component at the end of the GIL is selected from the calculation results and recorded as 5. The GIL fault location method based on the combination of SVMD and TEO as claimed in claim 4, characterized in that: calculate The TEO of the wave head at the first and last ends is used to calibrate the arrival time of the wave head at the first and last ends. The calculation formula of TEO is: In the formula, for TEO; In the formula, for TEO; The time when the initial fault wave reaches the GIL head end and GIL end measurement point corresponds to the horizontal coordinate of the maximum peak value, which is denoted as t S With t M .

6. The GIL fault location method based on the combination of SVMD and TEO as claimed in claim 5, characterized in that: The calculation formula of the traveling wave velocity is: Where, L is the inductance per unit length of GIL; C is the capacitance per unit length of GIL; The fault distance is calculated by the double-terminal traveling wave fault distance measurement formula. The calculation formula is: Where l is the length of GIL; d fS is the distance between the fault point and the head end.

7. The GIL fault location method based on the combination of SVMD and TEO as claimed in claim 6, characterized in that: Methods for detecting fault points include: When the SO2 gas concentration is less than or equal to 1μL / L, the evaluation result is normal; When the SO2 gas concentration is 1-5 μL / L, the detection cycle is shortened; When the SO2 gas concentration is 5-10μL / L, follow-up detection and comprehensive diagnosis are carried out; When the SO2 gas concentration is greater than 10μL / L, a comprehensive diagnosis is performed; When the H2S gas concentration is less than or equal to 1μL / L, the evaluation result is normal; When the H2S gas concentration is 1-2μL / L, follow-up detection and comprehensive diagnosis are performed; When the H2S gas concentration is greater than 5μL / L, a comprehensive diagnosis is performed.

8. A GIL fault distance measurement system based on the combination of SVMD and TEO, based on the GIL fault distance measurement method based on the combination of SVMD and TEO according to any one of claims 1 to 7, characterized in that: It includes an acquisition module, a calculation module, and an analysis module; The acquisition module is used to collect three-phase current data at both ends of the GIL; The calculation module is used to calculate the three-phase current data and process the current traveling wave line mode component; The analysis module is used to detect the fault point.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the GIL fault location method based on the combination of SVMD and TEO as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the GIL fault location method based on the combination of SVMD and TEO as described in any one of claims 1 to 7 are implemented.

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