Pulse injection-based system for power transmission line grounding fault distance measurement

Abstract

A pulse injection-based system for power transmission line grounding fault distance measurement comprises a pulse generator, a voltage measurement module and an isolation magnetic ring. The utility model provides a power transmission line grounding fault distance measurement and identification device based on a pulse injection method. A magnetic ring is connected in series on a working grounding wire at the outer side of a power transmission line test point to form large inductance and isolate a high-frequency pulse signal, so that the pulse signal is only transmitted to the inner side of the line, and the grounding fault of the power transmission line is identified and positioned in a ranging manner according to the time delay of a reflected signal after the transmission of the line. Accurate identification and positioning of the grounding fault of the power transmission line with working grounding are realized. The isolation magnetic ring is added to prevent pulse injection signals from directly entering the ground. Therefore, the pulse can be measured on the working grounded power transmission line. The device is used for power transmission line grounding fault distance measurement.

Description

Technical Field

[0001] This utility model relates to the field of electrical testing technology, specifically to a pulse injection-based system for measuring grounding faults in transmission lines. Background Technology

[0002] Before newly constructed transmission lines are put into operation, a series of electrical tests are required to ensure that their electrical performance meets design requirements and guarantees the safe and stable operation of the power system. The main electrical tests include insulation performance testing, conductor resistance testing, grounding testing, and line parameter measurement. During testing, the line must be grounded by installing grounding wires. However, after testing, grounding wires may not be removed for various reasons, necessitating manual inspection of the line to check for any remaining grounding wires. Furthermore, there may be instances of metal conductors being grounded, which cannot be detected visually. Once the line is put into operation, this can lead to accidents such as overcurrent and relay protection activation.

[0003] Before a transmission line is put into operation, a short-circuit grounding test is required. Traditional testing methods involve applying a withstand voltage to the transmission line for insulation testing. However, due to the long distances of transmission lines and the presence of working grounding at the line's ends, the withstand voltage test will inevitably reveal a grounding fault. It is impossible to identify a grounding fault at a specific point in the middle of the line. Utility Model Content

[0004] The purpose of this invention is to provide a pulse injection-based system for ground fault location in power transmission lines, comprising: a pulse generator, a voltage measurement module, and an isolation magnetic ring.

[0005] The circuit topology of the pulse generator is shown below:

[0006] Let the end of the DC power supply with the positive terminal be terminal A, and the end with the negative terminal be terminal B, with terminal B grounded.

[0007] Terminal A is connected to the drain of switch S1, the source of switch S1 is connected to the drain of switch S2, the source of switch S2 is connected to the drain of switch S3, the source of switch S3 is connected to the drain of switch S4, and the source of switch S4 is connected to terminal B.

[0008] The drain of the switch S1 is connected in sequence to a resistor R11, a capacitor C11, and then to the source of the switch S1.

[0009] The drain of switch S1 is connected to the source of switch S1 via resistor R12.

[0010] The drain of the switch S2 is connected in sequence to resistor R21 and capacitor C21, and then connected to the source of the switch S2.

[0011] The drain of the switch S2 is connected to the source of the switch S2 through a resistor R22.

[0012] The drain of the switch S3 is connected to the source of the switch S3 through a resistor R31 and a capacitor C31.

[0013] The drain of the switch S3 is connected to the source of the switch S3 through a resistor R32.

[0014] The drain of the switch S4 is connected to the source of the switch S4 through a resistor R41 and a capacitor C41.

[0015] The drain of the switch S4 is connected to the source of the switch S4 through a resistor R42.

[0016] The drain of the switch S3 and the source of the switch S4 serve as the output terminal of the pulse generator, outputting a pulse signal.

[0017] The pulse generator is connected in series with a voltage measurement module to form a voltage measurement circuit.

[0018] The voltage measurement circuit is connected in parallel to a power transmission line.

[0019] The isolation magnetic ring is connected in series to a working ground line of the power transmission line.

[0020] The pulse generator generates a pulse signal, which is converted into a pulse traveling wave on the power transmission line for propagation.

[0021] The fault ground of the power transmission line receives the pulse traveling wave and generates a pulse reflection wave.

[0022] The voltage measurement module receives the pulse reflection wave.

[0023] Further, the isolation magnetic ring forms an inductance on the working ground line of the power transmission line, preventing the pulse traveling wave from being injected into the ground through the working ground line.

[0024] Further, the pulse width of the pulse voltage output by the pulse generator ranges from 100ns to 1000ns.

[0025] The frequency of the pulse voltage output by the pulse generator ranges from 1Hz to 100Hz.

[0026] Further, the switches S1, S2, S3, and S4 are all mosfet switches.

[0027] The voltage amplitude output by the power supply DC ranges from 0 to 5000V.

[0028] The pulse amplitude output by the pulse generator ranges from 0 to 5kV.

[0029] Further, the voltage measurement module comprises a resistive voltage divider.

[0030] Further, the pulse voltage outputted by the pulse generator is a square wave pulse.

[0031] Further, the measurement range of the voltage measurement module is 1V-5kV.

[0032] Further, the measurement frequency band of the voltage measurement module is DC-10MHz.

[0033] Further, the inductance value formed by the isolation magnetic ring on the working grounding wire of the power transmission line is not less than 10muH.

[0034] Further, the voltage measurement module calculates the position of the fault grounding of the power transmission line by recording the arrival time of the pulse reflection wave.

[0035] The technical effect of the utility model is self-evident, and the utility model provides a kind of based on pulse injection system for power transmission line grounding fault ranging.By being strung into magnetic ring on working grounding wire outside power transmission line test point, large inductance is formed, high-frequency pulse signal is isolated, so as to ensure that pulse signal only spreads to inside line, and according to the time delay of reflected signal after line propagation, the grounding fault of power transmission line is identified and ranging positioning.Accurate identification and positioning of the grounding fault of power transmission line with working grounding are realized.

[0036] The utility model is used for power transmission line grounding fault ranging.

[0037] The utility model increases isolation magnetic ring, prevents that pulse injection signal directly enters ground, so as to ensure that pulse can be measured on power transmission line with working grounding. ACCURACY

[0038] Figure 1 It is power transmission line grounding fault ranging method schematic diagram based on pulse injection method;

[0039] Figure 2 It is high-voltage pulse generator circuit principle diagram;

[0040] Figure 3 It is pulse injection ranging and waveform reflection schematic diagram;

[0041] Figure 4 It is the power transmission line distribution parameter simulation diagram with length of 100km;

[0042] Figure 5 It is power transmission line simulation model pulse injection and reflection waveform schematic diagram;

[0043] Figure 6Fig. 1 is a schematic diagram of a transmission line pulse injection and reflected waveform. DETAILED DESCRIPTION

[0044] The utility model will be further described below in combination with examples, but should not be understood as the above-mentioned subject range of the utility model is limited to the following examples. According to the ordinary technical knowledge and conventional means in the art, various substitutions and changes are made without departing from the above-mentioned technical thought of the utility model, and all should be included in the protection scope of the utility model.

[0045] Example 1:

[0046] Reference Figures 1 to 6 A pulse injection system based on transmission line grounding fault ranging, comprising: a pulse generator, a voltage measurement module, an isolation magnetic ring.

[0047] The circuit topology of the pulse generator is as follows:

[0048] Denote the end where the positive pole of the power supply DC is as A end, and the end where the negative pole is as B end, and the B end is grounded.

[0049] The drain of the switch S1 is connected to the source of the switch S1, the source of the switch S1 is connected to the drain of the switch S2, the source of the switch S2 is connected to the drain of the switch S3, the source of the switch S3 is connected to the drain of the switch S4, and the source of the switch S4 is connected to the B end.

[0050] The drain of the switch S1 is connected to the source of the switch S1 after being connected to the resistance R11 and the capacitor C11 in sequence.

[0051] The drain of the switch S1 is connected to the source of the switch S1 after being connected to the resistance R12.

[0052] The drain of the switch S2 is connected to the source of the switch S2 after being connected to the resistance R21 and the capacitor C21 in sequence.

[0053] The drain of the switch S2 is connected to the source of the switch S2 after being connected to the resistance R22.

[0054] The drain of the switch S3 is connected to the source of the switch S3 after being connected to the resistance R31 and the capacitor C31 in sequence.

[0055] The drain of the switch S3 is connected to the source of the switch S3 after being connected to the resistance R32.

[0056] The drain of the switch S4 is connected to the source of the switch S4 after being connected to the resistance R41 and the capacitor C41 in sequence.

[0057] The drain of the switch S4 is connected to the source of the switch S4 after being connected to the resistance R42.

[0058] The drain of the switch S3 and the source of the switch S4 serve as the output end of the pulse generator, outputting a pulse signal.

[0059] The pulse generator is connected in series with a voltage measurement module to form a voltage measurement circuit.

[0060] The voltage measurement circuit is connected in parallel on the power transmission line.

[0061] The isolation magnetic ring is connected in series on the working ground wire of the power transmission line.

[0062] The pulse generator generates a pulse signal, which is converted into a pulse traveling wave on the power transmission line for propagation.

[0063] The pulse traveling wave is received at the fault ground of the power transmission line, and a pulse reflection wave is generated.

[0064] The voltage measurement module receives the pulse reflection wave.

[0065] Embodiment 2:

[0066] A pulse injection system based on the power transmission line grounding fault ranging, the main technical content is seen in embodiment 1, further, the isolation magnetic ring forms an inductor on the working ground wire of the power transmission line, preventing the pulse traveling wave from being injected into the ground through the working ground wire.

[0067] Embodiment 3:

[0068] A pulse injection system based on the power transmission line grounding fault ranging, the main technical content is seen in any one of embodiments 1 to 2, further, the pulse width of the pulse voltage output by the pulse generator ranges from 100ns to 1000ns.

[0069] The frequency of the pulse voltage output by the pulse generator ranges from 1Hz to 100Hz.

[0070] Embodiment 4:

[0071] A pulse injection system based on the power transmission line grounding fault ranging, the main technical content is seen in any one of embodiments 1 to 3, further, the switches S1, S2, S3 and S4 are all mosfet switches.

[0072] The voltage amplitude output by the power supply DC ranges from 0 to 5000V.

[0073] The pulse amplitude output by the pulse generator ranges from 0 to 5kV.

[0074] Embodiment 5:

[0075] The application discloses a pulse injection system for grounding fault location of a power transmission line, and relates to the technical field of power transmission lines.

[0076] Embodiment 6:

[0077] The application discloses a pulse injection system for grounding fault location of a power transmission line, and relates to the technical field of power transmission lines.

[0078] Embodiment 7:

[0079] The application discloses a pulse injection system for grounding fault location of a power transmission line, and relates to the technical field of power transmission lines.

[0080] Embodiment 8:

[0081] The application discloses a pulse injection system for grounding fault location of a power transmission line, and relates to the technical field of power transmission lines.

[0082] Embodiment 9:

[0083] The application discloses a pulse injection system for grounding fault location of a power transmission line, and relates to the technical field of power transmission lines.

[0084] Embodiment 10:

[0085] The application discloses a pulse injection system for grounding fault location of a power transmission line, and relates to the technical field of power transmission lines.

[0086] Embodiment 11:

[0087] Referring to Figures 1 to 6 The application discloses a pulse injection system for grounding fault location of a power transmission line, and relates to the technical field of power transmission lines.

[0088] The circuit topology of the pulse generator is shown as follows:

[0089] One end where a DC positive electrode of a power source is located is defined as an A end, one end where a DC negative electrode of the power source is located is defined as a B end, and the B end is grounded.

[0090] The drain of the switch S1 is connected to the source of the switch S1, the drain of the switch S2 is connected to the source of the switch S2, the drain of the switch S3 is connected to the source of the switch S3, the drain of the switch S4 is connected to the source of the switch S4, and the source of the switch S4 is connected to the B terminal.

[0091] The drain of the switch S1 is connected to the source of the switch S1 in sequence through the resistor R11 and the capacitor C11.

[0092] The drain of the switch S1 is connected to the source of the switch S1 through the resistor R12.

[0093] The drain of the switch S2 is connected to the source of the switch S2 in sequence through the resistor R21 and the capacitor C21.

[0094] The drain of the switch S2 is connected to the source of the switch S2 through the resistor R22.

[0095] The drain of the switch S3 is connected to the source of the switch S3 in sequence through the resistor R31 and the capacitor C31.

[0096] The drain of the switch S3 is connected to the source of the switch S3 through the resistor R32.

[0097] The drain of the switch S4 is connected to the source of the switch S4 in sequence through the resistor R41 and the capacitor C41.

[0098] The drain of the switch S4 is connected to the source of the switch S4 through the resistor R42.

[0099] The drain of the switch S3 and the source of the switch S4 serve as the output terminal of the pulse generator and output a pulse signal.

[0100] The pulse generator is connected in series with the voltage measurement module to form a voltage measurement circuit.

[0101] The voltage measurement circuit is connected in parallel to the power transmission line.

[0102] The isolation magnetic ring is connected in series to the working ground wire of the power transmission line.

[0103] The pulse generator generates a pulse signal, which is converted into a pulse traveling wave on the power transmission line for propagation.

[0104] The pulse traveling wave is received at the fault ground of the power transmission line and generates a pulse reflection wave.

[0105] The voltage measurement module receives the pulse reflection wave.

[0106] Embodiment 12:

[0107] The application discloses a pulse injection system for grounding fault ranging of a power transmission line, and mainly relates to the technical content of any one of embodiments 11 to 13.

[0108] Embodiment 13

[0109] The application discloses a pulse injection system for grounding fault ranging of a power transmission line, and mainly relates to the technical content of any one of embodiments 11 to 12, and further, the pulse width of the pulse voltage output by the pulse generator ranges from 100 ns to 1000 ns.

[0110] The frequency of the pulse voltage output by the pulse generator ranges from 1 Hz to 100 Hz.

[0111] Embodiment 14

[0112] The application discloses a pulse injection system for grounding fault ranging of a power transmission line, and mainly relates to the technical content of any one of embodiments 11 to 13, and further, the switches S1, S2, S3 and S4 are all mosfet switches.

[0113] The voltage amplitude output by the power supply DC ranges from 0 to 5000 V.

[0114] The pulse amplitude output by the pulse generator ranges from 0 to 5 kV.

[0115] Embodiment 15

[0116] The application discloses a pulse injection system for grounding fault ranging of a power transmission line, and mainly relates to the technical content of any one of embodiments 11 to 14, and further, the voltage measurement module comprises a resistance voltage divider.

[0117] The resistance voltage divider is connected in series with the pulse generator, the arrival time of the pulse reflection wave is recorded by measuring the voltage change between the resistance voltage divider.

[0118] Embodiment 16

[0119] The application discloses a pulse injection system for grounding fault ranging of a power transmission line, and mainly relates to the technical content of any one of embodiments 11 to 15, and further, the pulse voltage output by the pulse generator is a square wave pulse.

[0120] Embodiment 17

[0121] The application discloses a pulse injection system for grounding fault ranging of a power transmission line, and mainly relates to the technical content of any one of embodiments 11 to 16, and further, the measurement range of the voltage measurement module is 1 V to 5 kV.

[0122] Embodiment 18

[0123] A pulse injection-based system for ground fault location in transmission lines is provided. The main technical contents are described in any one of embodiments 11 to 17. Furthermore, the voltage measurement module has a measurement frequency band of DC-10MHz, which enables accurate measurement of pulse injection parameters and reflected wave parameters.

[0124] Example 19:

[0125] A pulse injection-based system for ground fault location of transmission lines, the main technical contents of which are described in any one of Embodiments 11 to 18, further wherein the inductance value formed by the isolation magnetic ring on the working grounding wire of the transmission line is not less than 10μH.

[0126] The isolation magnetic ring is a large-sized magnetic ring that is fitted onto the working grounding wire of the transmission line, forming an inductance value ≥10μH, which can effectively isolate the pulses output by the pulse generator.

[0127] Example 20:

[0128] A pulse injection-based system for measuring ground faults in transmission lines is provided. The main technical contents are described in any one of embodiments 11 to 19. Furthermore, the voltage measurement module calculates the location of the ground fault in the transmission line by recording the arrival time of the pulse reflected wave.

[0129] The location of the fault grounding point of the transmission line is shown below:

[0130]

[0131] In the formula, L is the distance from the fault grounding point to the voltage measurement line. T2 is the arrival time of the pulse reflected wave. T0 is the starting time for the pulse voltage to transform into a pulse traveling wave and propagate on the transmission line. V is the propagation speed of the traveling wave.

[0132] Example 21:

[0133] A pulse injection-based system for measuring ground faults in transmission lines is provided. The main technical contents are described in any one of embodiments 11 to 20. Furthermore, the system is used for measuring ground faults in transmission lines.

[0134] The steps for using the system to locate ground faults in transmission lines include:

[0135] 1) Place the isolation magnetic ring on the working grounding wire of the transmission line.

[0136] 2) Connect the output of the pulse generator in series with the voltage measurement module to form a voltage measurement circuit, and connect the voltage measurement circuit in parallel to the transmission line.

[0137] 3) The pulse generator outputs a pulse voltage, which is converted into a traveling pulse wave on the transmission line for propagation.

[0138] 4) When the traveling pulse wave propagates to the fault grounding point of the transmission line, a pulse reflection occurs at the fault grounding point, and the generated pulse reflection wave propagates in the opposite direction to the voltage measurement line.

[0139] 5) The voltage measurement module records the arrival time of the pulse reflected wave and calculates the location of the fault grounding point of the transmission line based on the traveling wave propagation speed.

[0140] Example 22:

[0141] See Figures 1 to 6 A pulse injection-based system for ground fault location in transmission lines, the main technical contents of which include:

[0142] The device includes a high-voltage pulse generator, a voltage measurement module, and an isolation magnetic ring.

[0143] The pulse generator can output square wave pulses with the following parameters: amplitude 1kV-5kV, pulse width 100ns-1000ns, and frequency 1-100Hz.

[0144] The main structure of the voltage measurement module is a resistive voltage divider, with a measurement range of 1V-5kV and a measurement frequency band of DC-10MHz, which enables accurate measurement of pulse injection parameters and reflected wave parameters.

[0145] The isolation magnetic ring is a large-sized magnetic ring that is fitted onto the working grounding wire of the transmission line, forming an inductance value ≥10μH, which can effectively isolate the pulses output by the pulse generator.

[0146] The main innovation of this patent is the addition of an isolation magnetic ring, which prevents the pulse injection signal from directly entering the ground. This ensures that the pulse can be measured on the power transmission line that is grounded.

[0147] Its basic working principle is (see) Figure 1 )

[0148] 1) Before the ground fault location experiment, place the isolation magnetic ring on the working grounding wire (e.g., Figure 1 (As shown on the left).

[0149] 2) Connect the output of the pulse generator to the power transmission line, and connect the voltage measurement module between the power transmission line and the ground at the same location.

[0150] 3) The high-voltage pulse generator outputs a high-voltage pulse, which is injected into the transmission line (at time T0).

[0151] 4) The traveling pulse will propagate along the transmission line, but because there is an isolation magnetic ring on the left side of the transmission line, the magnetic ring will form a large inductance, which isolates the traveling pulse and prevents it from propagating to the left, that is, it will not be injected into the ground through the working ground. This ensures that the traveling pulse will not attenuate rapidly due to grounding.

[0152] 5) The pulse traveling wave propagates to the right on the transmission line until it reaches the fault grounding point, i.e., at time T1. Due to the line grounding, the wave impedance of the transmission line will decrease sharply, and therefore it will be reflected at the fault grounding point.

[0153] 6) The pulse reflection wave will propagate to the left until it reaches the voltage measurement module, i.e., time T2. At this time, the arrival time of the reflected wave can be measured.

[0154] 7) Record the arrival time T2 at the measurement module. Based on the traveling wave propagation speed V, the following can be determined:

[0155] L = (T2-T0)*V

[0156] To determine the distance to the fault ground, 2.

[0157] Pulse generator circuit diagram as follows Figure 2 As shown. The high-voltage DC power supply parameters are adjustable from 0-5000V.

[0158] Switches S1, S2, S3, and S4 are all MOSFET switches, each with a withstand voltage of 3.3kV. To output a 5kV pulse voltage, two switches are connected in series. As shown in the diagram above, switches S1 and S2 operate in series, and switches S3 and S4 operate in series. This results in an adjustable high-voltage pulse output of 0-5kV.

[0159] The schematic diagram of pulse injection ranging is as follows: Figure 3 As shown.

[0160] A square wave pulse is injected, encounters a grounding point on the line, is reflected, and then the reflected wave is transmitted in the opposite direction to the measurement point, thereby calculating the time to determine the location of the grounding point.

[0161] For a typical single-conductor overhead transmission line, the impedance Z≈500Ω. With split conductors, the capacitance increases while the inductance decreases, resulting in a smaller surge impedance, which is approximately Z≈300Ω. The simulated surge impedance can be taken as 300Ω.

[0162] For overhead transmission lines, ε and μ are usually approximated as 1, which gives the propagation speed of traveling waves in overhead transmission lines as equivalent to the speed of light in a vacuum, i.e., 3 × 10⁸ m / s.

[0163] Based on relevant data, the parameters for the line are set as L = 1.27 mH / km and C = 0.014 uF / km.

[0164] When the total length L of the line is 100km, the total inductance of the line can be approximately expressed as L*L0, and the capacitance to ground as L*C0.

[0165] The established circuit model is as follows Figure 4 As shown. Simulation diagram of a 100km transmission line, with pulse duration set to 10µs and single-pulse voltage amplitude set to 300V.

[0166] A ground fault is simulated at kilometer 55 of the line, and the simulated waveform is as follows. Figure 5 As shown, the reflection time is 370 μs, according to the formula... The distance to the fault grounding point can be calculated.

[0167] Where V is the speed of travel wave propagation, taken as the speed of light, 300,000 km / s.

[0168] Therefore, L = 55km is calculated, which is consistent with the distance set for fault grounding. This verifies the feasibility of this method.

[0169] Example 23:

[0170] A pulse injection-based system for ground fault location in transmission lines is described in Example 22. Further, to verify the principle of the above technology, a ground fault test was conducted on a transmission line. The test wiring is as follows: Figure 1 Consistent. The fault grounding point is 3km away. The pulse injection and reflection waveforms are as follows: Figure 6 As shown.

[0171] from Figure 6 It can be seen that at time T0, a high voltage pulse of 2kV and 1μs is injected. After 20μs (at time T2), the reflected wave is acquired by the voltage measurement module. At this time, the time difference is T2-T0=20μs.

[0172] From the formula The distance to the fault grounding point can be calculated.

[0173] Where V is the speed of travel wave propagation, taken as the speed of light, 300,000 km / s.

[0174] Therefore, L = 3km is calculated, which is consistent with the distance set for fault grounding. This verifies the feasibility of this method.

Claims

1. A pulse injection-based system for ground fault location in transmission lines, characterized in that, include: Pulse generator, voltage measurement module, isolation magnetic ring; The circuit topology of the pulse generator is shown below: Let the end of the DC power supply with the positive terminal be terminal A, and the end with the negative terminal be terminal B, with terminal B grounded; Terminal A is connected to the drain of switch S1, the source of switch S1 is connected to the drain of switch S2, the source of switch S2 is connected to the drain of switch S3, the source of switch S3 is connected to the drain of switch S4, and the source of switch S4 is connected to terminal B. The drain of the switch S1 is connected to the resistor R11 and the capacitor C11 in sequence, and then connected to the source of the switch S1. The drain of switch S1 is connected to the source of switch S1 after the resistor R12 is connected. The drain of the switch S2 is connected in sequence to resistor R21 and capacitor C21, and then connected to the source of the switch S2. The drain of switch S2 is connected to the source of switch S2 after the resistor R22 is connected. The drain of the switch S3 is connected in sequence to resistor R31 and capacitor C31, and then connected to the source of the switch S3. The drain of switch S3 is connected to the source of switch S3 after the resistor R32 is connected. The drain of the switch S4 is connected to the source of the switch S4 after being connected to the resistor R41 and the capacitor C41 in sequence. The drain of switch S4 is connected to the source of switch S4 after the resistor R42 is connected. The drain of switch S3 and the source of switch S4 serve as the output terminals of the pulse generator, outputting a pulse signal. The pulse generator is connected in series with the voltage measurement module to form a voltage measurement circuit; The voltage measurement circuit is connected in parallel to the transmission line; The isolation magnetic ring is connected in series with the working grounding wire of the transmission line; The pulse generator produces a pulse signal, which is converted into a traveling pulse wave and propagates on the transmission line. The fault grounding point of the transmission line receives a pulse traveling wave and generates a pulse reflected wave; The voltage measurement module receives pulse reflected waves.

2. The pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The isolation magnetic ring forms an inductance on the working grounding wire of the transmission line to prevent pulse traveling waves from being injected into the ground through the working grounding wire.

3. The pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The pulse width range of the pulse voltage output by the pulse generator is 100ns-1000ns; The frequency range of the pulse voltage output by the pulse generator is 1Hz-100Hz.

4. A pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The switches S1, S2, S3, and S4 are all MOSFET switches; The voltage amplitude range of the DC output of the power supply is 0-5000V; The pulse generator outputs pulses with an amplitude range of 0-5kV.

5. A pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The voltage measurement module includes a resistive voltage divider.

6. A pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The pulse voltage output by the pulse generator is a square wave pulse.

7. A pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The voltage measurement module has a measurement range of 1V-5kV.

8. A pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The voltage measurement module has a measurement frequency band of DC-10MHz.

9. A pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The inductance value formed by the isolation magnetic ring on the working grounding wire of the transmission line is not less than 10μH.

10. A pulse injection-based system for ground fault location in transmission lines according to claim 1, characterized in that, The voltage measurement module calculates the location of the fault grounding point of the transmission line by recording the arrival time of the pulse reflected wave.

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