A high-precision matrix traveling wave positioning system and method thereof

Abstract

This invention discloses a high-precision matrix-type traveling wave positioning system, comprising a high-frequency current sensor installed on a high-voltage cable, a traveling wave collector connected to the high-frequency current sensor, a data aggregation unit connected to several traveling wave collectors, a system master station, a signal converter, and a high-voltage oscillation cabinet. The output of the data aggregation unit is connected to the system master station, and the output of the system master station is sequentially connected to the signal converter and the high-voltage oscillation cabinet. The other end of the high-voltage oscillation cabinet is connected to the high-voltage cable. The high-voltage oscillation cabinet includes a high-voltage switch, a grounding transformer, and an arc suppression coil. A high-precision matrix-type traveling wave positioning method is also disclosed. By controlling the closing and opening of the high-voltage switch through the system master station, multiple current traveling waves are generated, increasing the number of detections and detection accuracy. Multiple sets of traveling wave data are collected, realizing the transformation from a single set of data lines into a complete data matrix, significantly improving the positioning accuracy of the traveling wave positioning system.

Description

Technical Field

[0001] This invention relates to the field of power system safety protection technology, and in particular to a high-precision matrix traveling wave positioning system and method thereof. Background Technology

[0002] High-voltage cables are a crucial component of power systems, undertaking the critical task of transmitting electrical energy from power plants to substations and users. Their safe and stable operation directly affects the reliability and power quality of the entire power system. With rapid urbanization and increasing electricity demand, the use of high-voltage cables is constantly increasing, and their operating environments are becoming increasingly complex, such as underground laying and traversing complex terrain. This significantly increases the risk of cable failures. Once a cable fault occurs, prolonged troubleshooting leads to extended power outages, causing substantial economic losses for users and businesses. Therefore, how to quickly and accurately locate the specific fault point and isolate it in a timely manner to prevent the fault from escalating and causing greater impact on enterprises has become an important research direction in the field of power systems.

[0003] Currently, the most common cable fault location equipment on the market is the traveling wave positioning system. When a high-voltage cable is energized, if a ground fault occurs on one of its lines, the voltage of the line will suddenly drop from high voltage (6KV, 10KV, 35KV, 66KV, etc.), thereby generating electromagnetic waves (i.e., traveling waves) emitted from the fault point to both ends of the cable. By detecting some key parameters of this traveling wave, the specific location of the fault point in the cable can be determined; this is the traveling wave positioning system.

[0004] The schematic diagram of a conventional traveling wave positioning system is as follows: Figure 1 As shown, when a grounding fault occurs in a high-voltage cable, a traveling wave is emitted from the fault point to both ends of the cable. A high-frequency current sensor is installed on the cable, and a traveling wave data acquisition unit is connected to the high-frequency current sensor. The traveling wave data acquisition unit integrates a main control unit (CPU module), a high-speed current data acquisition unit (DAU module), and a communication module. Upon detecting the traveling wave signal, several traveling wave data acquisition units transmit the signal to the upper-level data aggregation unit. The data aggregation unit converts the data and then transmits it to the upper-level master station. After data processing, the master station uses either single-end ranging or double-end ranging methods to send the calculation results to the subsequent management platform for user viewing and use.

[0005] Conventional traveling wave positioning systems mostly employ traveling wave ranging and detection algorithms based on a single-wave longitudinal wave detection algorithm (referred to as single-wave longitudinal wave detection). However, due to the low energy and small amplitude of traveling waves during faults, their inherent characteristics such as refraction and attenuation, and their extremely high transmission speed, single-wave longitudinal wave detection has significant shortcomings in identifying the first wave and reflected waves, leading to large accuracy and errors in judgment. Therefore, improving the traveling wave energy and increasing the number of detections to enhance the overall positioning accuracy has become the most critical challenge for this system. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a high-precision matrix traveling wave positioning system and method, which can realize the transformation from a single set of data rows into a complete data matrix, providing a more solid foundation for the implementation of various first wave judgment algorithms in the later stage, and greatly improving the positioning accuracy and anti-interference capability of the traveling wave positioning system.

[0007] To solve the above-mentioned technical problems, one technical solution adopted by the present invention is: to provide a high-precision matrix traveling wave positioning system, including a high-frequency current sensor installed on a high-voltage cable, a traveling wave collector connected to the high-frequency current sensor, a data collection unit connected to several traveling wave collectors, a system master station, a signal converter, and a high-voltage oscillation cabinet;

[0008] The output of the data aggregation unit is connected to the system master station, and the output of the system master station is connected in sequence to the signal converter and the high-voltage oscillation cabinet. The primary circuit of the high-voltage oscillation cabinet is connected to the high-voltage cable.

[0009] The high-voltage oscillation cabinet is a primary high-voltage device that includes a high-voltage switch, a grounding transformer, and an arc suppression coil.

[0010] In a preferred embodiment of the present invention, the grounding transformer is connected in series with the high-voltage switch, the arc suppression coil is connected in parallel with the high-voltage switch, the control terminal of the high-voltage switch is connected to a signal converter and the other end is grounded, and the other end of the grounding transformer is connected to a high-voltage cable.

[0011] In a preferred embodiment of the present invention, the high-voltage switch is one or two of the following: a high-voltage vacuum circuit breaker, a high-voltage load switch, a high-voltage contactor, a high-voltage grounding switch, or a high-voltage solid-state switch, used in series.

[0012] In a preferred embodiment of the present invention, the system main station is also connected to a backend management platform.

[0013] To solve the above-mentioned technical problems, the second technical solution adopted by the present invention is: to provide a traveling wave positioning method using the high-precision matrix traveling wave positioning system as described in any of the above claims, the method being as follows:

[0014] After the system master station collects the first traveling wave current data when a ground fault occurs in the operating high-voltage cable, it sends an optical fiber signal to the signal converter. The signal converter outputs a pulse closing command to control the high-voltage switch to close, generating a second traveling wave current.

[0015] After the system's main station collects the second traveling wave current data, it summarizes the first and second traveling wave current data into a data matrix. By processing this data matrix and then calculating using either the single-end ranging method or the double-end ranging method, the location information of the fault point can be obtained.

[0016] In a preferred embodiment of the present invention, the amplitude of the second traveling wave current is much larger than the amplitude of the first traveling wave current.

[0017] To solve the above-mentioned technical problems, the third technical solution adopted by the present invention is: to provide a traveling wave positioning method using the high-precision matrix traveling wave positioning system as described in any one of the above claims, the method being as follows:

[0018] After the system master station collects the first traveling wave current data when a ground fault occurs in the operating high-voltage cable, it sends an optical fiber signal to the signal converter. The signal converter outputs a pulse closing command to control the high-voltage switch to close, generating a second traveling wave current.

[0019] After the system master station collects the second traveling wave current data, it sends a pulse tripping command to the high-voltage switch through the signal converter, generating the third traveling wave current.

[0020] Similarly, the traveling wave positioning system emits multiple traveling current waves. The system master station summarizes the data detected after multiple traveling wave currents into a data matrix. By processing the data matrix and then calculating using the single-end ranging method or the double-end ranging method, the fault location information can be obtained.

[0021] In a preferred embodiment of the present invention, the amplitude of the second traveling wave current is much larger than the amplitude of the first traveling wave current, and the amplitude of the third traveling wave current is slightly smaller than the amplitude of the first traveling wave current.

[0022] The beneficial effects of this invention are as follows: By designing a unique primary and secondary high-low voltage fusion hardware architecture and a novel matrix-type traveling wave positioning method, this invention enhances the traveling wave energy, increases the traveling wave current amplitude, improves the system detection accuracy, and also increases the number of detections. By collecting multiple sets of traveling wave data, it realizes the transformation from a single set of data rows into a complete data matrix, providing a more solid foundation for the implementation of various first wave judgment algorithms in the later stages. This greatly facilitates the more accurate determination of the timing of the first wave and the reflected wave, thus significantly improving the positioning accuracy of the traveling wave positioning system. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the principle of an existing conventional traveling wave positioning system;

[0024] Figure 2 This is a schematic diagram of the principle of the high-precision matrix traveling wave positioning system of the present invention;

[0025] Figure 3 This is a schematic diagram of a matrix traveling wave positioning waveform acquired in a preferred embodiment. Detailed Implementation

[0026] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0027] Please see Figure 2 and Figure 3 The embodiments of the present invention include:

[0028] A high-precision matrix traveling wave positioning system includes a high-frequency current sensor installed on a high-voltage cable, a traveling wave collector connected to the high-frequency current sensor, a data collection unit connected to several traveling wave collectors, a system master station, a signal converter, a background management platform, and a high-voltage oscillation cabinet.

[0029] The output of the data collection unit is connected to the system master station. The output of the system master station is connected in sequence to the signal converter and the high-voltage oscillation cabinet (secondary circuit). The primary circuit of the high-voltage oscillation cabinet is connected to the high-voltage cable. The output of the system master station is also connected to the background management platform for users to view and use the test results.

[0030] The high-voltage oscillation cabinet is a primary high-voltage device comprising a high-voltage switch, a grounding transformer, and an arc-suppression coil. The grounding transformer is connected in series with the high-voltage switch, and the arc-suppression coil is connected in parallel with the high-voltage switch. The control terminal of the high-voltage switch is connected to a signal converter, and the other terminal is grounded. The other terminal of the grounding transformer is connected to a high-voltage cable.

[0031] Preferably, the high-voltage switch is one or two of the following: a high-voltage vacuum circuit breaker, a high-voltage load switch, a high-voltage contactor, a high-voltage grounding switch, or a high-voltage solid-state switch, used in series. When two are used in series, one can be connected in series between the grounding transformer and the high-voltage cable, and the other can be installed at the lower end of the grounding transformer, or both switches can be installed at the lower end of the grounding transformer simultaneously. The signal converter mainly receives signals from the system master station, performs internal calculations, and then issues pulse closing or pulse opening commands to control the closing and opening of the high-voltage switch. The signal converter can be built into the system master station or installed near the system master station, using optical fiber for signal transmission without affecting the overall hardware design architecture of the system.

[0032] The matrix traveling wave positioning system forms a unique primary and secondary high and low voltage integrated hardware architecture by adding a high-voltage oscillation cabinet.

[0033] Combination Figure 3 The present invention also provides a matrix traveling wave positioning method using the high-precision matrix traveling wave positioning system, the method being as follows:

[0034] After the system master station collects the first traveling wave current data when a ground fault occurs in the operating high-voltage cable, it sends an optical fiber signal to the signal converter. The signal converter outputs a pulse closing command to control the high-voltage switch to close, generating a second traveling wave current.

[0035] After the system's main station collects the second traveling wave current data, it summarizes the first and second traveling wave current data into a data matrix. By processing this data matrix and then calculating using either the single-end ranging method or the double-end ranging method, the location information of the fault point can be obtained.

[0036] Furthermore, after the system master station collects the second traveling wave current data, it can send a pulse tripping command to the high-voltage switch through a signal converter to generate a third traveling wave current.

[0037] The system master station summarizes the first traveling wave current data and the data detected after the second and third traveling wave currents into a data matrix. By processing this data matrix and then calculating using the single-end ranging method or the double-end ranging method, the fault location information can be obtained.

[0038] Furthermore, the system master station can again control the high-voltage switch to close and open, generating the fourth and fifth traveling wave current curves.

[0039] Similarly, the traveling wave positioning system emits multiple traveling current waves. The system master station summarizes the data detected after multiple traveling wave currents into a data matrix. By processing the data matrix and then calculating using the single-end ranging method or the double-end ranging method, the location information of the fault point can be obtained.

[0040] The working principle of the matrix-type traveling wave positioning system for achieving traveling wave positioning is explained in detail below:

[0041] When a ground fault occurs in an operating high-voltage cable, a traveling wave is emitted from the fault point to both ends of the cable. High-frequency current sensors installed on the cable detect this and transmit the signal to traveling wave acquisition units. Several traveling wave acquisition units collect the signal and transmit it to the upper-level data aggregation unit. The data aggregation unit summarizes the data and then transmits it to the upper-level system master station, thus generating the first traveling wave current curve. The system master station collects the first set of traveling wave current data, i.e., the initial traveling wave current, which has a very low amplitude. After receiving the first set of traveling wave current data, the system master station sends an optical fiber signal to the signal converter. The signal converter, after internal calculation, outputs a pulse signal to drive the high-voltage switch in the high-voltage oscillation cabinet to close. The primary high-voltage power supply system forms a current loop through the grounding transformer, high-voltage switch, earth, ground fault point, and faulty cable, thus generating a second traveling wave current curve. The second traveling wave current is generated by the primary high-voltage system, and its amplitude is much larger than the ground capacitance current amplitude of the first traveling wave current. After the system master station receives the second set of traveling wave current data, it sends a tripping command to the high-voltage switch via a signal converter. The primary high-voltage power supply system forms a current loop through the grounding transformer, arc suppression coil, earth, ground fault point, and faulty cable, generating a third traveling wave current curve. Because the arc suppression coil inductively cancels out the current in the line, the amplitude of this traveling wave current is slightly smaller than the first. Similarly, the high-voltage switch can be controlled to close and open again, generating a fourth and fifth traveling wave current curve. The specific traveling wave current detection waveform is as follows: Figure 3 As shown, due to the inherently small detection error of the high-frequency current sensor, the differences between the traveling wave current waveforms and the collected data of the fourth and second (fifth and third) tests are also extremely small.

[0042] Since the amplitudes of the first two traveling wave currents already show significant differences, selecting the first two sets of data for post-processing usually yields good results. In this case, the arc suppression coil in the high-voltage oscillation cabinet can be retained or removed. To further improve the system's detection accuracy, the first three or more traveling wave current data sets can be selected for post-processing. For example, selecting the first m traveling wave current data sets for post-processing, the data point acquired in the first traveling wave acquisition is (a... 10 ,b 10 (a 11 ,b 11 ), ... (a 1n ,b 1n ), where a 10 b represents the first wave of time data collected in this data collection session. 10 The reflected wave time data for the first data acquisition point is given. The data acquired by the second traveling wave acquisition is (a) 20 ,b 20 (a 21 ,b 21 ), ... (a 2n,b 2n The data collected during the m-th traveling wave is (a) m0 ,b m0 (a m1 ,b m1 ), ... (a mn ,b mn The final summarized data matrix is The difference t is obtained by subtracting the initial wave time data and the reflected wave time data obtained for each data point in the data matrix, forming a new data matrix. The final data obtained by comparing all the data in the matrix, removing the smallest and then the largest, and averaging the remaining data is the accurate time difference t between the first wave and the reflected wave.

[0043] The accurate location information can be obtained by substituting the precise time difference between the first wave and the reflected wave obtained after the above processing into the single-end ranging method (or double-end ranging method) for simple calculation. The single-end ranging method involves installing a traveling wave current detection device (such as a high-precision current sensor) at the beginning of the cable. The arrival times of the first and reflected waves of the traveling wave current at the detection device are then collected. The distance from the fault point to the cable's beginning is obtained by multiplying the time difference by the wave velocity and dividing by 2, thus pinpointing the fault's exact location. The double-end ranging method involves installing traveling wave current detection devices at both the beginning and end of the cable. When the fault point emits traveling waves towards both ends of the cable, the first wave times of the traveling wave current in both directions are collected by the two detection devices. Combined with parameters such as wave velocity, the specific location of the fault point within the cable can be determined.

[0044] The matrix traveling wave positioning system forms a unique primary and secondary high- and low-voltage integrated hardware architecture by adding a high-voltage oscillation cabinet. This integrated architecture design changes the original power supply system from an ungrounded neutral point to a grounded state, constructing a new traveling wave current loop and generating a new traveling wave current with a significantly increased amplitude. Under the premise of the same detection error of the high-frequency current sensor, the substantial increase in the amplitude of the traveling wave current can also significantly improve the detection accuracy of the traveling wave positioning system.

[0045] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A high-precision matrix traveling wave positioning system, characterized in that, It includes a high-frequency current sensor installed on the high-voltage cable, a traveling wave data acquisition unit connected to the high-frequency current sensor, a data collection unit connected to several traveling wave data acquisition units, a system master station, a signal converter, and a high-voltage oscillation cabinet. The output of the data aggregation unit is connected to the system master station, and the output of the system master station is connected in sequence to the signal converter and the high-voltage oscillation cabinet. The primary circuit of the high-voltage oscillation cabinet is connected to the high-voltage cable. The high-voltage oscillation cabinet is a primary high-voltage device including a high-voltage switch, a grounding transformer, and an arc-suppression coil; The primary high-voltage power supply system forms a current loop through the grounding transformer, high-voltage switch, earth, grounding fault point, and faulty cable, thereby generating a second traveling wave current curve. The second traveling wave current is generated by the primary high-voltage system, and its amplitude is much larger than the amplitude of the ground capacitance current of the first traveling wave current.

2. The high-precision matrix traveling wave positioning system according to claim 1, characterized in that, The grounding transformer is connected in series with the high-voltage switch, the arc suppression coil is connected in parallel with the high-voltage switch, the control terminal of the high-voltage switch is connected to the signal converter and the other end is grounded, and the other end of the grounding transformer is connected to the high-voltage cable.

3. The high-precision matrix traveling wave positioning system according to claim 1, characterized in that, The high-voltage switch is one or two of the following: a high-voltage vacuum circuit breaker, a high-voltage load switch, a high-voltage contactor, a high-voltage grounding switch, or a high-voltage solid-state switch, used in series.

4. The high-precision matrix traveling wave positioning system according to claim 1, characterized in that, The system's main station is also connected to a backend management platform.

5. A high-precision matrix traveling wave positioning method using the high-precision matrix traveling wave positioning system as described in any one of claims 1 to 4, characterized in that, After the system master station collects the first traveling wave current data when a ground fault occurs in the operating high-voltage cable, it sends an optical fiber signal to the signal converter. The signal converter outputs a pulse closing command to control the high-voltage switch to close, generating a second traveling wave current. After the system's main station collects the second traveling wave current data, it summarizes the first and second traveling wave current data into a data matrix. By processing this data matrix and then calculating using either the single-end ranging method or the double-end ranging method, the location information of the fault point can be obtained.

6. The high-precision matrix traveling wave positioning method according to claim 5, characterized in that, The amplitude of the second traveling wave current is greater than that of the first traveling wave current.

7. A high-precision matrix traveling wave positioning method employing the high-precision matrix traveling wave positioning system as described in any one of claims 1 to 4, characterized in that, After the system master station collects the first traveling wave current data when a ground fault occurs in the operating high-voltage cable, it sends an optical fiber signal to the signal converter. The signal converter outputs a pulse closing command to control the high-voltage switch to close, generating a second traveling wave current. After the system master station collects the second traveling wave current data, it sends a pulse tripping command to the high-voltage switch through the signal converter, generating the third traveling wave current. Similarly, the traveling wave positioning system emits multiple traveling current waves. The system master station summarizes the data detected after multiple traveling wave currents into a data matrix. By processing the data matrix and then calculating using the single-end ranging method or the double-end ranging method, the fault location information can be obtained.

8. The high-precision matrix traveling wave positioning method according to claim 7, characterized in that, The amplitude of the second traveling wave current is greater than that of the first traveling wave current, and the amplitude of the third traveling wave current is less than that of the first traveling wave current.

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