Fault positioning method and system for gas-insulated metal-enclosed transmission line

Abstract

The invention discloses a fault positioning method and system for a gas-insulated metal-enclosed transmission line, and the method comprises the steps: collecting the first receiving time and first frequency of a first fault traveling wave signal of a first fault point through a traveling wave sensor, and filtering the first fault traveling wave signal through a first filter according to the first frequency, acquiring second receiving time of the first fault sound wave signal of the first fault point through the ultrasonic sensor, and finally obtaining the fault position of the first fault point according to the first receiving time, the second receiving time and the transmission speed of the traveling wave and the sound wave. Wherein a plurality of fault signal acquisition units which are arranged on the gas-insulated metal-enclosed power transmission line at intervals along the line respectively comprise a traveling wave sensor and an ultrasonic sensor. According to the invention, the fault can be positioned through a single end, and the problem that double ends cannot accurately position under the condition of multiple fault points is avoided; and meanwhile, the acquired signals can be ensured not to interfere with each other through filtering, so that the positioning result is more accurate.

Description

Technical Field

[0001] The present invention relates to the field of operation and maintenance of electrical equipment, and particularly to a fault location method and system for a gas-insulated metal-enclosed transmission line. Background Art

[0002] A gas-insulated metal-enclosed transmission line (GIL) is a high-voltage and large-capacity power transmission device, which is widely used in scenarios such as ultra-high voltage power transmission, urban underground power grids, and nuclear power plants. Its core feature is that it uses compressed gas (such as SF 6 or a mixed gas) as the insulating medium, and seals the current-carrying conductor in a metal shell, having advantages such as high reliability, low loss, and anti-electromagnetic interference.

[0003] The fault location of a gas-insulated metal-enclosed transmission line (GIL) is one of the key technologies to ensure the safe and stable operation of the power grid. As a high-voltage and large-current power transmission equipment with high-voltage gas insulation and coaxial arrangement of the metal shell and the conductor, GIL has the advantages of large power transmission capacity, less land occupation, high reliability, and long service life, and is widely used in ultra-high voltage power grids. However, due to its special structure and operating environment, once a fault occurs in GIL, quickly and accurately locating the fault point is crucial for reducing power outage time and improving operation and maintenance efficiency.

[0004] Currently, the commonly used fault location methods include the time-domain reflectometry method, the traveling wave location method, and the partial discharge detection method, etc. Among them, the time-domain reflectometry method has disadvantages such as low resolution of multiple fault points, easy signal confusion, serious attenuation of long-distance signals resulting in a decline in location accuracy, inability to distinguish fault types, and poor adaptability to complex structures (such as branches and joints); the traveling wave location method usually requires detecting units to be set at both ends, and then locates the fault position according to the time difference of the received fault traveling waves. This leads to inaccurate location if there are multiple fault points between the two detecting units because the detected signals are not the same fault signal; the partial discharge detection method is easily affected by noise, may have false detections or missed detections, and can only roughly locate, unable to accurately locate to a point. At the same time, it depends on the discharge intensity and is difficult to detect weak signals, mainly used for preventive maintenance, with insufficient real-time performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to provide a fault location method and system for a gas-insulated metal-enclosed transmission line, which can ensure that the collected signals do not interfere with each other and effectively achieve accurate location of multiple fault points.

[0006] To solve the above technical problem, the technical solution adopted by the present invention is: A fault location method for a gas-insulated metal-enclosed transmission line includes the steps: S1. In response to the traveling wave sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line collecting the first fault traveling wave signal of the first fault point, obtain the first reception time and the first frequency of the first fault traveling wave signal, and filter the first fault traveling wave signal by using a first filter according to the first frequency; S2. In response to the ultrasonic sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line collecting the first fault acoustic wave signal of the first fault point, obtain the second reception time of the first fault acoustic wave signal; S3. According to the first reception time, the second reception time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line, obtain the fault position of the first fault point.

[0007] To solve the above technical problems, another technical solution adopted by the present invention is: A fault location system for a gas-insulated metal-enclosed transmission line includes a traveling wave fault signal acquisition module, an acoustic wave fault signal acquisition module, and a fault position determination module; The traveling wave fault signal acquisition module is configured to, in response to the traveling wave sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line collecting the first fault traveling wave signal of the first fault point, obtain the first reception time and the first frequency of the first fault traveling wave signal, and filter the first fault traveling wave signal by adjusting the filtering frequency of a first filter according to the first frequency. A plurality of the traveling wave sensors are arranged at intervals along the gas-insulated metal-enclosed transmission line; The acoustic wave fault signal acquisition module is configured to, in response to the ultrasonic sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line collecting the first fault acoustic wave signal of the first fault point, obtain the second reception time of the first fault acoustic wave signal. A plurality of the ultrasonic sensors are arranged at intervals along the gas-insulated metal-enclosed transmission line; The fault position determination module is configured to obtain the fault position of the first fault point according to the first reception time, the second reception time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line.

[0008] The beneficial effects of the present invention are as follows: A fault location method and system for a gas-insulated metal-enclosed transmission line are provided. Through a fault signal acquisition unit arranged at a single end, single-end fault detection is realized, avoiding the problem that traditional double-end detection cannot accurately locate in the case of multiple fault points. By combining the time difference between the traveling wave signal (fast propagation) and the acoustic wave signal (slow propagation), the fault location is accurately calculated, improving the reliability of location. At the same time, the filter is dynamically adjusted according to the traveling wave frequency to eliminate the interference of high-frequency traveling waves on the acoustic wave signal, ensuring that the collected signals do not interfere with each other and making the location result more accurate. Description of the Drawings

[0009] Figure 1 is a flowchart of a fault location method for a gas-insulated metal-enclosed transmission line according to an embodiment of the present invention; Figure 2 is a schematic structural diagram of a fault location system for a gas-insulated metal-enclosed transmission line according to an embodiment of the present invention; Figure 3 is a schematic structural diagram of a fault signal acquisition unit according to an embodiment of the present invention.

[0010] Label Description: 201, traveling wave fault signal acquisition module; 202, acoustic wave fault signal acquisition module; 203, fault location determination module; 301, traveling wave sensor; 302, ultrasonic sensor; 303, first electronic switch; 304, fault detection line; 305, first filter; 306, second electronic switch. Detailed Embodiment

[0011] To describe the technical content, achieved objectives and effects of the present invention in detail, the following is described in conjunction with the embodiments and with reference to the drawings.

[0012] Please refer to Figure 1 , a fault location method for a gas-insulated metal-enclosed transmission line, including the steps: S1. In response to the traveling wave sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line collecting the first fault traveling wave signal of the first fault point, obtaining the first reception time and the first frequency of the first fault traveling wave signal, and filtering the first fault traveling wave signal according to the first frequency by using a first filter; S2. In response to the ultrasonic sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line collecting the first fault acoustic wave signal of the first fault point, obtaining the second reception time of the first fault acoustic wave signal; S3. Obtain the fault location of the first fault point according to the first reception time, the second reception time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line.

[0013] As can be seen from the above description, the beneficial effects of the present invention are as follows: A fault location method for a gas-insulated metal-enclosed transmission line is provided. Through a fault signal acquisition unit arranged at a single end, single-end fault detection is realized, avoiding the problem that traditional double-end detection cannot accurately locate in the case of multiple fault points. By combining the time difference between the traveling wave signal (fast propagation) and the acoustic wave signal (slow propagation), the fault location is accurately calculated, improving the positioning reliability. At the same time, the filter is dynamically adjusted according to the traveling wave frequency to eliminate the interference of high-frequency traveling waves on the acoustic wave signal, ensuring that the collected signals do not interfere with each other, and making the positioning result more accurate.

[0014] Further, the traveling wave sensor is connected to the fault detection line through a first electronic switch, and the ultrasonic sensor is connected to the fault detection line through the first filter and a second electronic switch; After obtaining the first reception time and the first frequency of the first fault traveling wave signal in step S1, the following steps are further included: Close the first electronic switch and open the second electronic switch; The following steps are also included in step S2: If the traveling wave sensor does not collect a fault traveling wave signal, control the first electronic switch to remain open and control the second electronic switch to remain closed.

[0015] As can be seen from the above description, by switching the electronic switch (closing the traveling wave path and opening the acoustic wave path), the traveling wave and acoustic wave acquisition paths are isolated to avoid signal crosstalk, and during the fault detection process, when no fault is detected, the traveling wave path is kept open by default and the acoustic wave path is kept closed by default to reduce system energy consumption.

[0016] Further, step S3 is specifically as follows: Obtain the fault location of the first fault point: ; In the formula, L is the fault location of the first fault point, V 1 is the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, V 2 is the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line, t 1 is the first reception time, t2 is the second reception time, Δ t is the time difference between the first reception time and the second reception time.

[0017] As can be seen from the above description, by using the fixed speed difference between the traveling wave and the acoustic wave, the time difference is converted into a spatial distance, effectively improving the positioning accuracy.

[0018] Further, a plurality of fault signal acquisition units are arranged at intervals along the gas-insulated metal-enclosed transmission line. Each of the fault signal acquisition units has two traveling wave sensors with opposite acquisition directions and two ultrasonic sensors with opposite acquisition directions, which are respectively used to receive fault traveling wave signals or fault acoustic wave signals on both sides. The method further includes: In response to the fault signals at the fault point between two adjacent first fault signal acquisition units and second fault signal acquisition units being acquired, according to the fault traveling wave signal reception time and the fault acoustic wave reception time corresponding to the first fault signal acquisition unit, a first fault position is obtained. According to the fault traveling wave signal reception time and the fault acoustic wave reception time corresponding to the second fault signal acquisition unit, a second fault position is obtained. Judge whether the first fault position and the second fault position match. If so, it is determined that there is a unique fault point on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit. Otherwise, it is determined that there are at least two fault points on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit.

[0019] As can be seen from the above description, the bidirectionally arranged traveling wave and ultrasonic sensors can monitor faults on both sides of the line simultaneously, with a wider coverage range; at the same time, by comparing the fault positions collected by adjacent units, it is judged whether there are multiple fault points, that is, the number of fault points is further determined through double-end detection, solving the problem of missed detection of traditional double-end detection methods in multi-fault scenarios. And through the consistency verification method, if the fault positions calculated by the two units match, a single-point fault is confirmed. If they do not match, a multi-fault detection mechanism is triggered, enhancing the system's fault tolerance.

[0020] Further, if there are at least two fault points on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit, high-frequency pulse signals are injected into both sides respectively at any point on the transmission line between the first fault position and the second fault position, and the reception times of the reflected waves corresponding to the high-frequency pulse signals on both sides are received respectively to judge whether there are other fault points between the first fault position and the second fault position.

[0021] As described above, the reflection signal is actively excited by high-frequency pulse injection to locate the hidden fault point, making up for the deficiencies of passive detection. At the same time, by combining the time difference of the reflected waves, the positions and quantities of multiple fault points are accurately identified, especially suitable for dense fault scenarios, realizing the parallel operation of single-point fault location and double-point fault location. Overall, a closed-loop detection system is formed by combining passive signal capture (traveling wave / acoustic wave) with active pulse injection, improving the comprehensiveness of fault location.

[0022] Please refer to Figure 2 and Figure 3 , a fault location system for a gas-insulated metal-enclosed transmission line, comprising a traveling wave fault signal acquisition module, an acoustic wave fault signal acquisition module, and a fault location determination module; The traveling wave fault signal acquisition module is configured to obtain the first reception time and the first frequency of the first fault traveling wave signal in response to the first fault traveling wave signal collected by the traveling wave sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line, and filter the first fault traveling wave signal by adjusting the filtering frequency of the first filter according to the first frequency; The acoustic wave fault signal acquisition module is configured to obtain the second reception time of the first fault acoustic wave signal in response to the first fault acoustic wave signal collected by the ultrasonic sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line; The fault location determination module is configured to obtain the fault location of the first fault point according to the first reception time, the second reception time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line.

[0023] As described above, the beneficial effects of the present invention are as follows: Based on the same technical concept, in cooperation with the above-mentioned fault location method for a gas-insulated metal-enclosed transmission line, a fault location system for a gas-insulated metal-enclosed transmission line is provided. Through the fault signal acquisition unit arranged at a single end, single-end fault detection is realized, avoiding the problem that traditional double-end detection cannot accurately locate in the case of multiple fault points. By combining the time difference between the traveling wave signal (fast propagation) and the acoustic wave signal (slow propagation), the fault location is accurately calculated, improving the reliability of location. At the same time, the filter is dynamically adjusted according to the traveling wave frequency to eliminate the interference of high-frequency traveling waves on the acoustic wave signal, ensuring that the collected signals do not interfere with each other, making the location result more accurate.

[0024] Further, the traveling wave sensor is connected to the fault detection line through a first electronic switch, and the ultrasonic sensor is connected to the fault detection line through the first filter and a second electronic switch; After obtaining the first reception time and the first frequency of the first traveling wave fault signal, the traveling wave fault signal acquisition module is further configured to: Turn off the first electronic switch and turn on the second electronic switch; The traveling wave fault signal acquisition module is further configured to: When the traveling wave sensor does not collect a traveling wave fault signal, control the first electronic switch to remain on and control the second electronic switch to remain off.

[0025] As can be seen from the above description, by switching the electronic switch (closing the traveling wave path and opening the acoustic wave path), the traveling wave and acoustic wave acquisition paths are isolated to avoid signal crosstalk, and the default open state of the traveling wave path and the default closed state of the acoustic wave path are maintained when no fault is detected during the fault detection process to reduce system power consumption.

[0026] Further, the fault location determination module is specifically configured to: Obtain the fault location of the first fault point: ; where L is the fault location of the first fault point, V 1 is the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, V 2 is the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line, t 1 is the first reception time, t 2 is the second reception time, Δ t is the time difference between the first reception time and the second reception time.

[0027] As can be seen from the above description, by using the fixed speed difference between the traveling wave and the acoustic wave, the time difference is converted into a spatial distance, effectively improving the positioning accuracy.

[0028] Further, a plurality of fault signal acquisition units are arranged at intervals along the gas-insulated metal-enclosed transmission line. Each fault signal acquisition unit has two traveling wave sensors with opposite acquisition directions and two ultrasonic sensors with opposite acquisition directions, which are respectively used to receive the traveling wave fault signals or fault acoustic signals on both sides; The system further includes a multi-fault location acquisition module and a multi-fault determination module; The multi-fault location acquisition module is configured to respond to the fault signals of the fault point between two adjacent first fault signal acquisition units and second fault signal acquisition units, and obtain a first fault location according to the received time of the fault traveling wave signal and the received time of the fault acoustic wave corresponding to the first fault signal acquisition unit; The multi-fault location acquisition module is further configured to obtain a second fault location according to the received time of the fault traveling wave signal and the received time of the fault acoustic wave corresponding to the second fault signal acquisition unit; The multi-fault determination module is configured to determine whether the first fault location and the second fault location match. If so, it is determined that there is a unique fault point on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit; otherwise, it is determined that there are at least two fault points on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit.

[0029] As can be seen from the above description, the bidirectionally arranged traveling wave and ultrasonic sensors can monitor faults on both sides of the line simultaneously, with a wider coverage range; at the same time, by comparing the fault locations collected by adjacent units, it is judged whether there are multiple fault points, that is, the number of fault points is further determined through double-end detection, solving the problem of missed detection of traditional double-end detection methods in multi-fault scenarios. And through the consistency verification method, if the fault locations calculated by the two units match, a single-point fault is confirmed; if not, the multi-fault detection mechanism is triggered, enhancing the fault tolerance of the system.

[0030] Further, the system further includes a multi-fault point location determination module; The multi-fault point location determination module is configured to, when it is determined that there are at least two fault points on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit, inject high-frequency pulse signals to both sides of the transmission line between the first fault location and the second fault location, and determine whether there are other fault points between the first fault location and the second fault location according to the received time of the reflected waves corresponding to the high-frequency pulse signals.

[0031] As can be seen from the above description, by actively injecting high-frequency pulses to excite reflected signals, hidden fault points are located, making up for the deficiencies of passive detection; at the same time, combined with the time difference of reflected waves, the positions and quantities of multiple fault points are accurately identified, especially suitable for dense fault scenarios, realizing parallel single-point fault location and double-point fault location; overall, through the combination of passive signal capture (traveling wave / acoustic wave) and active pulse injection, a closed-loop detection system is formed, improving the comprehensiveness of fault location.

[0032] A fault location method and system for a gas-insulated metal-enclosed transmission line provided by the present invention are mainly applied to the fault location scenario of a gas-insulated metal-enclosed transmission line, and are specifically described below in conjunction with specific embodiments: Please refer to Figure 1 , the first embodiment of the present invention is: A fault location method for a gas-insulated metal-enclosed transmission line, as Figure 1 shown, includes the steps of: S1. In response to the first fault traveling wave signal of the first fault point collected by the traveling wave sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line, obtain the first reception time and the first frequency of the first fault traveling wave signal, and filter the first fault traveling wave signal by using a first filter according to the first frequency.

[0033] S2. In response to the first fault acoustic wave signal of the first fault point collected by the ultrasonic sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line, obtain the second reception time of the first fault acoustic wave signal.

[0034] S3. According to the first reception time, the second reception time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line, obtain the fault location of the first fault point, specifically: Obtain the fault location of the first fault point: (1); In the formula, L is the fault location of the first fault point, V 1 is the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, V 2 is the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line, t 1 is the first reception time, t 2 is the second reception time, Δ t is the time difference between the first reception time and the second reception time.

[0035] That is, in this embodiment, a single-ended fault signal acquisition unit is used to achieve single-ended fault detection. Specifically, the first fault traveling wave signal of the first fault point is collected at the same end to obtain the first reception time of the first fault traveling wave signal, and the first fault acoustic wave signal of the first fault point is collected to obtain the second reception time of the first fault acoustic wave signal, thus avoiding the problem that traditional double-ended detection cannot accurately locate in the case of multiple fault points. By combining the time difference between the traveling wave signal (fast propagation) and the acoustic wave signal (slow propagation), the fault location is accurately calculated, improving the positioning reliability. At the same time, the first frequency of the first fault traveling wave signal is obtained, and the filtering frequency of the first filter is dynamically adjusted according to the first frequency to filter the first fault traveling wave signal, eliminating the interference of high-frequency traveling waves on the acoustic wave signal, that is, ensuring that the first fault acoustic wave signal is not affected by the first fault traveling wave signal during the acquisition process (since the speed of the traveling wave signal is greater than that of the acoustic wave signal, the acoustic wave signal has not arrived when the traveling wave signal is collected, so there is no interference), solving the problem of the first fault traveling wave signal interfering with the first fault acoustic wave signal and improving the positioning accuracy. When calculating the fault location of the first fault point, the above formula is used to convert the time difference into a spatial distance by using the fixed speed difference between the traveling wave and the acoustic wave, effectively improving the positioning accuracy.

[0036] Wherein, in this embodiment, the traveling wave sensor is connected to the fault detection line through the first electronic switch, and the ultrasonic sensor is connected to the fault detection line through the first filter and the second electronic switch.

[0037] After obtaining the first reception time and the first frequency of the first fault traveling wave signal in step S1, the following steps are further included: Turn off the first electronic switch and turn on the second electronic switch.

[0038] At the same time, step S1 further includes: If the traveling wave sensor does not collect the fault traveling wave signal, control the first electronic switch to remain open and control the second electronic switch to remain closed.

[0039] That is, when the traveling wave sensor does not collect the fault traveling wave signal, the first electronic switch remains open and the second electronic switch remains closed to avoid the influence of the fault traveling wave signal on the ultrasonic sensor; while when the fault traveling wave signal is collected, the first electronic switch is turned off and the second electronic switch is turned on to avoid the influence of the fault acoustic wave signal on the traveling wave sensor. By switching the electronic switch (closing the traveling wave path and opening the acoustic wave path), the traveling wave and acoustic wave acquisition paths are isolated to avoid signal crosstalk. At the same time, when no fault is detected, the traveling wave path is kept open by default and the acoustic wave path is kept closed by default to reduce the system power consumption. This structure effectively ensures that the fault location is not interfered with and improves the positioning accuracy.

[0040] Embodiment 2 of the present invention is as follows: A fault location method for a gas-insulated metal-enclosed transmission line. On the basis of the above-mentioned Embodiment 1, in this embodiment, a plurality of fault signal acquisition units are arranged at intervals along the gas-insulated metal-enclosed transmission line. Each fault signal acquisition unit has two traveling wave sensors with opposite acquisition directions and two ultrasonic sensors with opposite acquisition directions, which are respectively used to receive fault traveling wave signals or fault acoustic signals on both sides.

[0041] That is, the bidirectionally arranged traveling wave and ultrasonic sensors can monitor faults on both sides of the line simultaneously, with a wider coverage range. At the same time, it should be noted that the fault signal acquisition units (except for the head and tail) can acquire fault signals of other two-side transmission lines.

[0042] At the same time, in this embodiment, the method further includes: In response to two adjacent first fault signal acquisition units and second fault signal acquisition units acquiring fault signals at a fault point between them, according to the received time of the fault traveling wave signal and the received time of the fault acoustic wave corresponding to the first fault signal acquisition unit, obtain the first fault location.

[0043] According to the received time of the fault traveling wave signal and the received time of the fault acoustic wave corresponding to the second fault signal acquisition unit, obtain the second fault location.

[0044] Judge whether the first fault location and the second fault location match. If so, it is determined that there is a unique fault point on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit; otherwise, it is determined that there are at least two fault points on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit.

[0045] That is, in this embodiment, it is also possible to determine whether there are multiple fault points by comparing the fault locations collected by adjacent units, that is, to further determine the number of fault points through double-end detection, solve the problem of missed detection of traditional double-end detection methods in multi-fault scenarios, and through a consistency verification method, if the fault locations calculated by the two units match, a single-point fault is confirmed, and if they do not match, a multi-fault detection mechanism is triggered to enhance the system's fault tolerance. In the above way, two fault points closer to both ends can be directly located, the number of multiple fault points can be determined, and the comprehensiveness of fault location is improved.

[0046] In addition, in this embodiment, if there are at least two fault points on the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit, then high-frequency pulse signals are injected into both sides at any point on the transmission line between the first fault location and the second fault location, and the received times of the reflected waves corresponding to the high-frequency pulse signals on both sides are respectively received to determine whether there are other fault points between the first fault location and the second fault location.

[0047] That is, by actively injecting high-frequency pulses to excite the reflection signal, the hidden fault point is located to make up for the deficiency of passive detection, and the positions of three or more fault points can be determined. At the same time, combined with the time difference of the reflected wave, the positions and quantities of multiple fault points are accurately identified, especially suitable for dense fault scenarios, realizing parallel single-point and double-point fault location. Overall, a closed-loop detection system is formed by combining passive signal capture (traveling wave / sonic wave) with active pulse injection, improving the comprehensiveness of fault location. It should be noted that the high-frequency pulse signal injection method belongs to active detection and cannot detect faults in time. Therefore, it is used after the fault location in this embodiment is initially completed to determine the fault.

[0048] Please refer to Figure 2 and Figure 3 , Embodiment 3 of the present invention is as follows: A fault location system for a gas-insulated metal-enclosed transmission line, as Figure 2 shown, includes a traveling wave fault signal acquisition module 201, an acoustic wave fault signal acquisition module 202, and a fault location determination module 203.

[0049] In this embodiment, fault signal acquisition units are arranged on the gas-insulated metal-enclosed transmission line. Among them, as Figure 3 shown, the fault signal acquisition unit includes a traveling wave sensor 301 and an ultrasonic sensor 302. At the same time, the traveling wave sensor 301 is connected to the fault detection line 304 through a first electronic switch 303, and the ultrasonic sensor 302 is connected to the fault detection line 304 through a first filter 305 and a second electronic switch 306.

[0050] The traveling wave fault signal acquisition module 201 is used to respond to the first fault traveling wave signal of the first fault point collected by the traveling wave sensor 301 of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line, obtain the first reception time and the first frequency of the first fault traveling wave signal, and filter the first fault traveling wave signal by adjusting the filtering frequency of the first filter 305 according to the first frequency.

[0051] The acoustic wave fault signal acquisition module 202 is used to respond to the first fault acoustic wave signal of the first fault point collected by the ultrasonic sensor 302 of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line, and obtain the second reception time of the first fault acoustic wave signal.

[0052] The fault location determination module 203 is used to obtain the fault location of the first fault point according to the first reception time, the second reception time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the acoustic wave on the gas-insulated metal-enclosed transmission line. The specific calculation process is as follows: Obtain the fault location of the first fault point: (1); Wherein, L is the fault location of the first fault point, V 1 is the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, V 2 is the transmission speed of the sound wave on the gas-insulated metal-enclosed transmission line, t 1 is the first reception time, t 2 is the second reception time, Δ t is the time difference between the first reception time and the second reception time.

[0053] That is, in this embodiment, through the fault signal acquisition unit arranged at one end, single-end fault detection is realized, that is, by collecting the first fault traveling wave signal of the first fault point at the same end to obtain the first reception time of the first fault traveling wave signal, and collecting the first fault sound wave signal of the first fault point to obtain the second reception time of the first fault sound wave signal, avoiding the problem that traditional double-end detection cannot accurately locate in the case of multiple fault points, and combining the time difference between the traveling wave signal (fast propagation) and the sound wave signal (slow propagation) to accurately calculate the fault location, improving the positioning reliability. At the same time, by obtaining the first frequency of the first fault traveling wave signal, the filtering frequency of the first filter 305 is dynamically adjusted according to the first frequency to filter the first fault traveling wave signal, eliminating the interference of the high-frequency traveling wave on the sound wave signal, that is, ensuring that the first fault sound wave signal is not affected by the first fault traveling wave signal during the acquisition process (the traveling wave signal speed is greater than the sound wave signal, so the sound wave signal has not arrived when the traveling wave signal is collected and will not cause interference), solving the problem that the first fault traveling wave signal interferes with the first fault sound wave signal and improving the positioning accuracy. Among them, when calculating the fault location of the first fault point, through the above formula, using the fixed speed difference between the traveling wave and the sound wave, the time difference is converted into a spatial distance, effectively improving the positioning accuracy.

[0054] Wherein, in this embodiment, after the traveling wave fault signal acquisition module 201 obtains the first reception time and the first frequency of the first fault traveling wave signal, it is further used for: Closing the first electronic switch 303 and opening the second electronic switch 306.

[0055] At the same time, the traveling wave fault signal acquisition module 201 is further used for: When the traveling wave sensor 301 does not collect the fault traveling wave signal, controlling the first electronic switch 303 to remain open and controlling the second electronic switch 306 to remain closed.

[0056] That is, when the traveling wave sensor 301 does not collect the fault traveling wave signal, the first electronic switch 303 remains open and the second electronic switch 306 remains closed to prevent the fault traveling wave signal from affecting the ultrasonic sensor 302. When the fault traveling wave signal is collected, the first electronic switch 303 is closed and the second electronic switch 306 is opened to prevent the fault acoustic wave signal from affecting the traveling wave sensor 301. By switching the electronic switch (closing the traveling wave path and opening the acoustic wave path), the traveling wave and acoustic wave acquisition paths are isolated to avoid signal crosstalk. At the same time, when no fault is detected, the default state of the traveling wave path is kept open and the default state of the acoustic wave path is kept closed to reduce system power consumption. This structure effectively ensures that the fault location is not interfered with and improves the location accuracy.

[0057] Embodiment 4 of the present invention is as follows: A fault location system for a gas-insulated metal-enclosed transmission line. On the basis of the above Embodiment 3, in this embodiment, a plurality of fault signal acquisition units are arranged at intervals along the gas-insulated metal-enclosed transmission line. Each fault signal acquisition unit has two traveling wave sensors 301 with opposite acquisition directions and two ultrasonic sensors 302 with opposite acquisition directions, which are respectively used to receive the fault traveling wave signals or fault acoustic wave signals on both sides.

[0058] That is, the traveling wave and ultrasonic sensors 302 arranged bidirectionally can simultaneously monitor faults on both sides of the line, covering a wider range. At the same time, it should be noted that the fault signal acquisition units (except for the head and tail) can collect the fault signals of other two-side transmission lines.

[0059] At the same time, in this embodiment, the system further includes a multi-fault location acquisition module and a multi-fault determination module.

[0060] The multi-fault location acquisition module is used to, in response to two adjacent first and second fault signal acquisition units collecting the fault signals of the fault point between them, obtain the first fault location according to the fault traveling wave signal reception time and the fault acoustic wave reception time corresponding to the first fault signal acquisition unit.

[0061] The multi-fault location acquisition module is further used to obtain the second fault location according to the fault traveling wave signal reception time and the fault acoustic wave reception time corresponding to the second fault signal acquisition unit.

[0062] The multi-fault determination module is used to determine whether the first fault location and the second fault location match. If so, it is determined that there is a unique fault point in the transmission line between the first and second fault signal acquisition units. Otherwise, it is determined that there are at least two fault points in the transmission line between the first and second fault signal acquisition units.

[0063] That is, in this embodiment, by comparing the fault positions collected by adjacent units, it is determined whether there are multiple fault points. That is, through double - end detection, the number of fault points is further determined, solving the problem of missed detection of traditional double - end detection methods in multi - fault scenarios. And through the consistency verification method, if the calculated fault positions of the two units match, a single - point fault is confirmed; if they do not match, a multi - fault detection mechanism is triggered, enhancing the system's fault tolerance. Through the above method, two fault points close to both ends can be directly located, the number of multiple fault points can be determined, and the comprehensiveness of fault location is improved.

[0064] In addition, the system further includes a multi - fault - point position determination module; The multi - fault - point position determination module is configured to, when it is determined that there are at least two fault points in the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit, inject high - frequency pulse signals to both sides respectively in the transmission line between the first fault position and the second fault position, and determine whether there are other fault points between the first fault position and the second fault position according to the reception time of the reflected waves corresponding to the high - frequency pulse signals.

[0065] That is, by actively injecting high - frequency pulses to excite reflected signals, hidden fault points are located, making up for the deficiencies of passive detection. The positions of three or more fault points can be determined. At the same time, combined with the time difference of reflected waves, the positions and quantities of multiple fault points are accurately identified, especially suitable for dense fault scenarios, realizing parallel single - point and double - point fault location. Overall, through the combination of passive signal capture (traveling wave / sonic wave) and active pulse injection, a closed - loop detection system is formed, improving the comprehensiveness of fault location. It should be noted that the high - frequency pulse signal injection method belongs to active detection and cannot detect faults in time. Therefore, it is used after the initial fault location in this embodiment is completed to determine the fault.

[0066] In summary, a fault location method and system for a gas - insulated metal - enclosed transmission line provided by the present invention have the following beneficial effects: 1. Single - end detection is used for fault detection and location, avoiding the problem that double - end detection cannot accurately locate in the case of multiple fault points.

[0067] 2. The problem of traveling - wave signal interfering with sonic - wave signal is solved through filtering, improving the positioning accuracy.

[0068] 3. Double - end detection is used for multiple fault points, and the number of multiple fault points can be determined, improving the comprehensiveness of fault location.

[0069] 4. Further location of multiple fault points determined by double - end is achieved by injecting high - frequency pulse signals.

[0070] The above are only embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical fields, shall similarly be included within the patent protection scope of the present invention.

Claims

1. A method for locating a fault of a gas-insulated metal-enclosed transmission line, characterized in that: Includes steps: S1, in response to a traveling wave sensor of a fault signal collection unit on a gas-insulated metal-enclosed transmission line collecting a first fault point's first fault traveling wave signal, obtaining a first receiving time and a first frequency of the first fault traveling wave signal, and filtering the first fault traveling wave signal using a first filter according to the first frequency; S2, in response to the ultrasonic sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line acquiring a first fault sound wave signal of the first fault point, obtaining a second receiving time of the first fault sound wave signal; S3. Obtain the fault position of the first fault point according to the first receiving time, the second receiving time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the sound wave in the gas-insulated metal-enclosed transmission line.

2. A method for locating a fault of a gas-insulated metal-enclosed transmission line according to claim 1, characterized in that: The traveling wave sensor is connected to the fault detection circuit via a first electronic switch, and the ultrasonic sensor is connected to the fault detection circuit via the first filter and a second electronic switch; After obtaining the first receiving time and the first frequency of the first fault traveling wave signal in step S1, the method further includes: Turn off the first electronic switch and turn on the second electronic switch; The step S2 also includes: If the traveling wave sensor does not collect the fault traveling wave signal, the first electronic switch is controlled to remain turned on, and the second electronic switch is controlled to remain turned off.

3. A method for locating a fault of a gas-insulated metal-enclosed transmission line according to claim 1, characterized in that: The step S3 is specifically as follows: Obtain the fault location of the first fault point: ； In the formula, L is the fault location of the first fault point, V 1 is the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, V 2 is the transmission speed of sound waves on the gas-insulated metal-enclosed transmission line, t 1 is the first receiving time, t 2 is the second receiving time, Δ t is the time difference between the first receiving time and the second receiving time.

4. A method for locating a fault of a gas-insulated metal-enclosed transmission line according to claim 1, characterized in that: A plurality of fault signal acquisition units are arranged at intervals along the gas-insulated metal-enclosed transmission line, each of the fault signal acquisition units having two traveling wave sensors with opposite collection directions and two ultrasonic sensors with opposite collection directions, respectively used to receive fault traveling wave signals or fault acoustic wave signals on both sides; The method further comprises: In response to two adjacent first fault signal acquisition units and second fault signal acquisition units acquiring fault signals of a fault point between the two, a first fault position is obtained according to a fault traveling wave signal receiving time and a fault sound wave receiving time corresponding to the first fault signal acquisition units; Obtaining a second fault position according to the fault traveling wave signal receiving time and the fault sound wave receiving time corresponding to the second fault signal acquisition unit; Determine whether the first fault position and the second fault position match. If so, determine that there is a unique fault point in the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit. Otherwise, determine that there are at least two fault points in the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit.

5. A method for locating a fault of a gas-insulated metal-enclosed transmission line according to claim 4, characterized in that: If there are at least two fault points in the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit, high-frequency pulse signals are injected to both sides at any point on the transmission line between the first fault position and the second fault position, and the reception time of the reflected waves corresponding to the high-frequency pulse signals on both sides is received respectively to determine whether there are other fault points between the first fault position and the second fault position.

6. A fault location system for a gas-insulated metal-enclosed transmission line, characterized in that: It includes a traveling wave fault signal acquisition module, an acoustic wave fault signal acquisition module and a fault location determination module; The traveling wave fault signal acquisition module is used to obtain a first receiving time and a first frequency of the first fault traveling wave signal in response to a traveling wave sensor of a fault signal acquisition unit on the gas-insulated metal-enclosed transmission line acquiring a first fault traveling wave signal of a first fault point, and adjust a filtering frequency of a first filter according to the first frequency to filter the first fault traveling wave signal; The acoustic wave fault signal acquisition module is used to obtain a second reception time of the first fault acoustic wave signal in response to the ultrasonic sensor of the fault signal acquisition unit on the gas-insulated metal-enclosed transmission line acquiring the first fault acoustic wave signal of the first fault point; The fault location determination module is used to obtain the fault location of the first fault point according to the first receiving time, the second receiving time, the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, and the transmission speed of the sound wave in the gas-insulated metal-enclosed transmission line.

7. The fault location system for a gas-insulated metal-enclosed transmission line according to claim 6, characterized in that: The traveling wave sensor is connected to the fault detection circuit via a first electronic switch, and the ultrasonic sensor is connected to the fault detection circuit via the first filter and a second electronic switch; After obtaining the first receiving time and the first frequency of the first fault traveling wave signal, the traveling wave fault signal acquisition module is further used to: Turn off the first electronic switch and turn on the second electronic switch; The traveling wave fault signal acquisition module is also used for: When the traveling wave sensor does not collect the fault traveling wave signal, the first electronic switch is controlled to remain turned on, and the second electronic switch is controlled to remain turned off.

8. The fault location system for a gas-insulated metal-enclosed transmission line according to claim 6, characterized in that: The fault location determination module is specifically used for: Obtain the fault location of the first fault point: ； In the formula, L is the fault location of the first fault point, V 1 is the transmission speed of the traveling wave in the gas-insulated metal-enclosed transmission line, V 2 is the transmission speed of sound waves on the gas-insulated metal-enclosed transmission line, t 1 is the first receiving time, t 2 is the second receiving time, Δ t is the time difference between the first receiving time and the second receiving time.

9. The fault location system for a gas-insulated metal-enclosed transmission line according to claim 6, characterized in that: A plurality of fault signal acquisition units are arranged at intervals along the gas-insulated metal-enclosed transmission line, each of the fault signal acquisition units having two traveling wave sensors with opposite collection directions and two ultrasonic sensors with opposite collection directions, respectively used to receive fault traveling wave signals or fault acoustic wave signals on both sides; The system also includes a multi-fault location acquisition module and a multi-fault determination module; The multi-fault position acquisition module is used to obtain a first fault position according to the fault traveling wave signal reception time and the fault sound wave reception time corresponding to the first fault signal acquisition unit in response to the fault signals of the fault point between the two adjacent first fault signal acquisition units and the second fault signal acquisition unit; The multi-fault position acquisition module is further used to obtain the second fault position according to the fault traveling wave signal reception time and the fault sound wave reception time corresponding to the second fault signal acquisition unit; The multiple fault determination module is used to determine whether the first fault position and the second fault position match. If so, it is determined that there is a unique fault point in the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit; otherwise, it is determined that there are at least two fault points in the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit.

10. The fault location system for a gas-insulated metal-enclosed power transmission line according to claim 9, characterized in that: The system also includes a multi-fault point location determination module; The multiple fault point location determination module is used to, if responding to the existence of at least two fault points in the transmission line between the first fault signal acquisition unit and the second fault signal acquisition unit, inject high-frequency pulse signals to both sides of the transmission line between the first fault position and the second fault position, and judge whether there are other fault points between the first fault position and the second fault position according to the reception time of the reflected wave corresponding to the high-frequency pulse signal.

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