A power distribution network overhead line single-phase ground fault positioning method and system

Abstract

The present application belongs to the technical field of power grid grounding fault positioning, and discloses a distribution network overhead line single-phase grounding fault positioning method and system, which comprises: simultaneously injecting alternating voltage and current on the measured overhead line, collecting electric field signals and magnetic field signals on the measured overhead line to calculate voltage instantaneous value and current instantaneous value, and respective full-cycle Fourier amplitudes; multiplying the product of voltage and current instantaneous values in one cycle, dividing the integral value by the product of voltage and current instantaneous value full-cycle Fourier amplitudes, obtaining the ratio coefficient at different positions on the measured overhead line, to construct the function of the ratio coefficient about different positions on the measured overhead line, and the single-phase grounding fault occurs at the maximum point of the first derivative of the function. The present application also provides reverse power supply based on a vehicle-mounted power supply combined with a distribution transformer, strengthens the amplitude of the injected signal, and cooperates with a UAV carrying electric field and magnetic field sensors to realize fast and accurate positioning of the single-phase grounding fault point of the distribution network, thereby improving the reliability of power supply.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power grid grounding fault positioning, and more particularly relates to a distribution network overhead line single-phase grounding fault positioning method and system. BACKGROUND

[0002] As one of the three systems of "power generation, power transmission and power distribution", the distribution network is directly connected with the power users. Unlike the transmission network with fewer branches, the distribution network has a complex structure, numerous branches and a complex and diverse environment, so its failure rate is much higher than that of the transmission network. Therefore, timely positioning and handling of the distribution network line fault can greatly improve the power supply reliability and thus improve the power experience of the directly connected users. Single-phase grounding fault is the most common fault form in the distribution network, and most short-circuit faults are developed from single-phase grounding faults.

[0003] The current solution to the single-phase grounding fault of the distribution network is mainly the signal injection method, which injects a specific current signal into the line through a signal generating device. The current forms a loop through the generating device, the fault line, the fault point and the ground. However, when the single-phase grounding fault criterion based on the signal injection method is used to identify the fault position, the difference between the magnetic field signals on both sides of the fault point is small due to the influence of the capacitive current of the overhead line, which affects the accuracy of the single-phase grounding fault position identification.

[0004] In addition, with the wide application of unmanned aerial vehicles (UAVs) in the power system, the use of UAVs carrying sensors for rapid identification and judgment of fault position information has also been developed in the process of distribution network fault inspection. However, due to the requirement of the flight distance between the UAV and the overhead line, the sensor carried on the UAV cannot be directly close to the overhead line, so that the measured fault signal is often very weak, and it is difficult to accurately position the fault position using the existing signal injection method. SUMMARY

[0005] In view of the above defects or improvement needs of the prior art, the present application provides a distribution network overhead line single-phase grounding fault positioning method and system, which aims to improve the accuracy of the single-phase grounding fault position identification of the distribution network overhead line.

[0006] To achieve the above-mentioned purpose, according to the first aspect of the present application, a distribution network overhead line single-phase grounding fault positioning method is provided, comprising:

[0007] After the single-phase grounding fault of the distribution network overhead line occurs, an alternating voltage and current are simultaneously injected into the measured overhead line, and the alternating voltage and current correspondingly generate an electric field and a magnetic field on the measured overhead line; and the electric field signal and the magnetic field signal on the measured overhead line are collected;

[0008] Calculate the voltage instantaneous value and the current instantaneous value at different positions on the measured overhead line based on the electric field signal and the magnetic field signal respectively; and calculate the full-cycle Fourier amplitude of the voltage instantaneous value and the current instantaneous value respectively;

[0009] Integrate the product of the voltage instantaneous value and the current instantaneous value in one electric field or magnetic field alternating period to obtain the integral value at different positions on the measured overhead line; divide the integral value by the product of the full-cycle Fourier amplitude of the voltage instantaneous value and the current instantaneous value to obtain the ratio coefficient at different positions on the measured overhead line, so as to construct a function of the ratio coefficient with respect to different positions on the measured overhead line; wherein, the position corresponding to the maximum value of the first derivative of the function is where the single-phase ground fault occurs.

[0010] Further, the AC voltage and current are simultaneously injected into the measured overhead line, including:

[0011] The storage battery and the inverter are carried on the maintenance vehicle, and the inverter converts the DC voltage and current generated by the storage battery into AC voltage and current, and then transmits the AC voltage and current to the distribution transformer through the high-voltage cable for voltage boosting; the boosted AC voltage and current are injected into the measured overhead line; wherein, the electric field signal and the magnetic field signal are collected by the electric field sensor and the magnetic field sensor carried on the unmanned aerial vehicle.

[0012] Further, the AC current frequency generated by the inverter is 60-100 Hz.

[0013] According to the second aspect of the present application, a single-phase ground fault positioning system for overhead lines of a distribution network is provided, including:

[0014] A signal injection module is configured to simultaneously inject AC voltage and current into the measured overhead line after the single-phase ground fault of the overhead line of the distribution network occurs, and the AC voltage and current correspondingly generate electric field and magnetic field on the measured overhead line.

[0015] An electric field sensor is configured to collect the electric field signal on the measured overhead line.

[0016] A magnetic field sensor is configured to collect the magnetic field signal on the measured overhead line.

[0017] The fault identification module is configured to calculate voltage instantaneous values and current instantaneous values at different positions on the measured overhead line based on the electric field signals and the magnetic field signals respectively, and to calculate full-cycle Fourier amplitudes of the voltage instantaneous values and the current instantaneous values respectively; and to integrate the product of the voltage instantaneous values and the current instantaneous values in one electric field or magnetic field alternating cycle to obtain integral values at the different positions on the measured overhead line; and to divide the integral values by the product of the full-cycle Fourier amplitudes of the voltage instantaneous values and the current instantaneous values to obtain ratio coefficients at the different positions on the measured overhead line, so as to construct a function of the ratio coefficients with respect to the different positions on the measured overhead line; wherein the position corresponding to the maximum value of the first derivative of the function is where the single-phase ground fault occurs.

[0018] Further, the unmanned aerial vehicle is further configured to carry the electric field sensor and the magnetic field sensor; and the signal injection module comprises a storage battery and an inverter carried on the maintenance vehicle.

[0019] The inverter is configured to invert the direct-current voltage and current generated by the storage battery into alternating-current voltage and current; wherein the alternating-current voltage and current are transmitted to a distribution transformer through a high-voltage cable for voltage boosting, and the voltage-boosted alternating-current voltage and current are injected into the measured overhead line.

[0020] Further, the unmanned aerial vehicle is further configured to carry the electric field sensor and the magnetic field sensor; and the signal injection module comprises a storage battery and an inverter carried on the maintenance vehicle.

[0021] The communication unit is configured to receive and store the electric field signals and the magnetic field signals collected by the electric field sensor and the magnetic field sensor, and to send the electric field signals and the magnetic field signals to the fault identification module.

[0022] Further, the electric field sensor is a three-dimensional electric field vector sensor with an arc-surface-to-position equidivision six-electrode structure.

[0023] Further, the magnetic field sensor is a giant magneto-impedance sensor.

[0024] In general, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0025] (1) Unlike the prior art which only detects the injected current, the present application provides a new signal injection method for single-phase ground fault positioning of overhead lines in distribution networks. In this method, an AC voltage and current are injected into the measured overhead line, which generates an electric field and a magnetic field on the measured overhead line. The voltage and current instantaneous values at different positions on the measured overhead line are obtained based on the electric field signal and the magnetic field signal. The product of the voltage instantaneous value and the current instantaneous value in one cycle is integrated. Since the measured current in the injected current and the injected voltage have the same phase, while the capacitive current in the injected current and the injected voltage have a phase difference of 90°, the product of the capacitive current and the injected voltage is 0 after integration in one cycle. Thus, the capacitive current in the injected current is separated from the measured current, and the influence of the capacitive current on single-phase ground fault positioning is eliminated. Based on this, a ratio coefficient function is constructed using the ratio of the integral value and the amplitude product value at different positions on the measured overhead line. The position of the ratio coefficient where the ratio coefficient suddenly changes is the position where the single-phase ground fault occurs. Therefore, the position corresponding to the maximum value of the first derivative of the function is the position where the single-phase ground fault occurs. The single-phase ground fault positioning method for overhead lines in distribution networks of the present application eliminates the influence of the capacitive current of the overhead line and improves the accuracy of fault location identification.

[0026] (2) Further, considering the requirement of flight distance between the UAV and the overhead line, the sensor mounted on the UAV cannot be directly attached to the overhead line, which makes the measured fault signal very weak. Based on this, the present application uses the distribution transformer to perform reverse power transmission. That is, unlike the conventional method of converting high voltage to low voltage by the distribution transformer and transmitting it to the user, the present application converts the low voltage AC voltage and current provided by the vehicle-mounted power supply into high voltage and current by using the distribution transformer, which greatly improves the voltage and current signals injected into the overhead line, so that the method of the present application can be applied to the rapid identification and judgment of fault position information by the UAV-mounted sensor.

[0027] Moreover, the present application uses the distribution transformer to perform reverse power transmission, which eliminates the need for manual pole-climbing and wire-hanging operations, saving manpower and ensuring the safety of the inspection personnel. At the same time, integrating the primary energy source (battery and inverter) on the inspection vehicle also improves the flexibility of the detection position.

[0028] (3) As a preferred embodiment, the frequency of the AC current output by the inverter is 60-100 Hz, which avoids the interference of the power frequency electromagnetic field (50 Hz) and improves the reverse power transmission efficiency.

[0029] (4) As preferred, the electric field sensor adopts a three-dimensional electric field vector sensor of an arc surface pair position equal six-electrode structure, can fully sense the electric field vector component in the space, has a wide frequency measurement capability in the range of 10MHz, and has good anti-angle measurement deviation characteristics.

[0030] (5) As preferred, the magnetic field sensor is a giant magneto impedance sensor, has the characteristics of high sensitivity, high linearity and high flexibility, and has a wide detection magnetic field range and good three-axis orthogonality, and can self-correct the magnetic field measurement error caused by the change of the sensor attitude caused by the movement of the unmanned aerial vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A power distribution network overhead line single-phase ground fault positioning method in the embodiment of the application is shown in the figure.

[0032] Figure 2 The flow direction of the injected signal when the power distribution transformer is reversed in the embodiment of the application is shown in the figure.

[0033] Figure 3 The equivalent circuit diagram of the system when a single-phase ground fault occurs in the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application. In addition, the technical features involved in each embodiment of the application described below can be combined with each other as long as they do not conflict with each other.

[0035] Embodiment 1

[0036] As shown in the figure, the embodiment of the application provides a power distribution network overhead line single-phase ground fault positioning method, mainly comprising: Figure 1

[0037] After the single-phase ground fault of the power distribution network overhead line occurs, an alternating voltage and an alternating current are injected into the measured overhead line at the same time, and the injected alternating voltage and alternating current correspondingly generate an electric field and a magnetic field on the measured overhead line; and the electric field signal and the magnetic field signal on the measured overhead line are collected;

[0038] The voltage instantaneous value at different positions on the measured overhead line is calculated based on the electric field signal, the current instantaneous value at different positions on the measured overhead line is calculated based on the magnetic field signal, and the full-cycle Fourier algorithm amplitude of the voltage instantaneous value and the current instantaneous value is calculated respectively.

[0039] ​The integral value of different positions on the measured overhead line is obtained by integrating the product of the voltage instantaneous value and the current instantaneous value in an alternating period of an electric field or a magnetic field; the amplitude product value of different positions on the measured overhead line is obtained by multiplying the full-cycle Fourier algorithm amplitude of the voltage instantaneous value and the full-cycle Fourier algorithm amplitude of the current instantaneous value; the ratio coefficient of different positions on the measured overhead line is obtained by dividing the integral value by the amplitude product value, so as to construct a function of the ratio coefficient with respect to different positions on the measured overhead line; wherein the single-phase ground fault occurs at the position corresponding to the maximum value of the first derivative of the function.

[0040] Unlike the existing method of only detecting injected current, the present application provides a new signal injection method for single-phase ground fault positioning of overhead lines of a distribution network, simultaneously injecting alternating voltage and current into the measured overhead line, and corresponding electric field and magnetic field are generated on the measured overhead line, and the voltage and current instantaneous values of different positions on the measured overhead line are obtained based on the electric field signal and the magnetic field signal; the product of the voltage instantaneous value and the current instantaneous value in a period is integrated, and since the to-be-measured current in the injected current and the injected voltage are consistent in phase, while the capacitive current in the injected current and the injected voltage are 90 degrees out of phase, the product of the capacitive current and the injected voltage is 0 after integration in a period, thus realizing the separation of the capacitive current and the to-be-measured current in the injected current and eliminating the influence of the capacitive current on single-phase ground fault positioning. Based on this, the ratio coefficient function is constructed based on the ratio of the integral value and the amplitude product value of different positions on the measured overhead line, and the single-phase ground fault occurs at the position where the ratio coefficient suddenly changes, therefore, the position corresponding to the maximum value of the first derivative of the function is the position where the single-phase ground fault occurs. The single-phase ground fault positioning method of the overhead lines of the distribution network of the present application eliminates the influence of the capacitive current of the overhead line and improves the accuracy of fault position identification.

[0041] In order to enable the method of the present application to be applied to unmanned aerial vehicle distribution network fault inspection, as a further design of the present application, when simultaneously injecting alternating voltage and current into the measured overhead line, the present application provides a signal injection method based on a vehicle-mounted power supply and an unmanned aerial vehicle-borne sensor, so as to greatly improve the injected alternating voltage and current on the overhead line, as shown in FIG. Figure 2 , specifically comprising:

[0042] The storage battery and the inverter are carried on the maintenance vehicle, and the inverter converts the direct-current voltage and current generated by the storage battery into alternating voltage and current, which is then transmitted to the distribution transformer through the high-voltage cable for voltage boosting; the boosted alternating voltage and current are transmitted to the measured overhead line; wherein the electric field signal and the magnetic field signal are collected by the electric field sensor and the magnetic field sensor carried on the unmanned aerial vehicle.

[0043] In the embodiment of the present application, the alternating voltage and current are fed back to the 10kV measured overhead line through the distribution transformer.

[0044] Preferably, the frequency of the alternating current output by the inverter is 60-100HZ, which improves the back-feeding efficiency while avoiding the interference of the power frequency electromagnetic field (50HZ).

[0045] In the embodiment of the present application, the battery is provided by the maintenance vehicle, and the capacity can reach 80ah. The vehicle-mounted inverter moves with the vehicle during maintenance, fully ensuring flexibility and portability.

[0046] In the present application, considering the requirement of the flight distance between the unmanned aerial vehicle and the overhead line, the sensor carried on the unmanned aerial vehicle cannot be directly close to the overhead line, so that the measured fault signal is often very weak. Based on this, the present application uses the distribution transformer for back-feeding. Under normal circumstances, the distribution transformer converts high voltage into low voltage and delivers it to the user, while in the present application, the distribution transformer converts the low voltage alternating voltage and current provided by the vehicle-mounted power supply into high voltage and current, greatly improving the voltage and current signals injected into the overhead line, so that the method of the present application can be applied to the rapid identification and judgment of the fault position information by the sensor carried on the unmanned aerial vehicle.

[0047] Moreover, the present application uses the distribution transformer for back-feeding, injecting signals at the low-voltage end of the distribution transformer, which saves manual pole-climbing and wire-hanging operations, saving manpower on the one hand and ensuring the safety of the inspection personnel on the other hand. At the same time, the integration of the primary energy (battery and inverter) on the maintenance vehicle also improves the flexibility of the detection position.

[0048] Embodiment 2

[0049] The embodiment of the present application provides a single-phase grounding fault positioning system for overhead lines of a power distribution network, mainly comprising:

[0050] A signal injection module is used to inject alternating voltage and current into the measured overhead line simultaneously after the single-phase grounding fault of the overhead lines of the power distribution network occurs, and the injected alternating voltage and current correspondingly generate electric field and magnetic field on the measured overhead line.

[0051] An electric field sensor is used to collect the electric field signal on the measured overhead line.

[0052] A magnetic field sensor is used to collect the magnetic field signal on the measured overhead line.

[0053] The fault identification module is configured to calculate voltage instantaneous values at different positions on the measured overhead line based on the electric field signals, calculate current instantaneous values at the different positions on the measured overhead line based on the magnetic field signals, and calculate full-cycle Fourier algorithm amplitudes of the voltage instantaneous values and the current instantaneous values respectively; and is further configured to integrate products of the voltage instantaneous values and the current instantaneous values in one cycle to obtain integral values at the different positions on the measured overhead line, multiply the full-cycle Fourier algorithm amplitudes of the voltage instantaneous values and the full-cycle Fourier algorithm amplitudes of the current instantaneous values to obtain amplitude product values at the different positions on the measured overhead line, and divide the integral values by the amplitude product values to obtain ratio coefficient values at the different positions on the measured overhead line, so as to construct a function of the ratio coefficient values with respect to the different positions on the measured overhead line; wherein a single-phase grounding fault occurs at a position corresponding to a maximum value of a first derivative of the function.

[0054] As a preferred implementation, the power distribution network overhead line single-phase grounding fault positioning system in the embodiment of the application further comprises a UAV for carrying the electric field sensor and the magnetic field sensor, and the signal injection module comprises a vehicle-mounted power supply output device. The vehicle-mounted power supply output device comprises a storage battery and an inverter carried on a maintenance vehicle.

[0055] The inverter is configured to invert direct-current voltage and current generated by the storage battery into alternating-current voltage and current; the alternating-current voltage and current are transmitted to a power distribution transformer through a high-voltage cable for voltage boosting; and the voltage-boosted alternating-current voltage and current are transmitted to the measured overhead line.

[0056] In the embodiment of the application, the electric field sensor is a three-dimensional electric field vector sensor adopting a six-electrode structure of arc surface pairing and equal division, can fully sense electric field vector components in space, has a wideband measurement capability in a range of 10 MHz, and has good anti-angle measurement deviation characteristics. In the embodiment of the application, the magnetic field sensor is a giant magneto-impedance sensor, has characteristics of high sensitivity, high linearity and high flexibility, and has a detection magnetic field range of 10-10-10-2T; the three axes are orthogonal, and can self-correct magnetic field measurement errors caused by changes in the sensor posture due to UAV movement.

[0057] As a preferred implementation, the UAV further comprises a communication unit carried thereon, configured to receive and store the electric field signals and the magnetic field signals collected by the electric field sensor and the magnetic field sensor, and transmit the electric field signals and the magnetic field signals to the fault identification module.

[0058] In the embodiment of the application, the fault identification module is a ground data processing device in the power distribution network overhead line single-phase grounding fault positioning system. Figure 2 The UAV, the electric field sensor, the magnetic field sensor and the communication unit carried on the UAV constitute a vehicle-mounted current output device.

[0059] As shown in Figure 3As shown, it is an equivalent circuit diagram of a power distribution network system when single-phase ground fault occurs in the embodiment of the application, U AB is the line voltage of AB phase line, BC is the line voltage of BC phase line, CA is the line voltage of CA phase line, C is the total ground capacitance of the whole line, C1 is the ground capacitance of the line before fault, C2 is the ground capacitance of the line after fault, and R is the resistance value of single-phase ground fault. After fault positioning by the power distribution network overhead line single-phase ground fault positioning method or system of the application, the position of the sudden change of the calculated ratio coefficient is at R, and it can be determined that the single-phase ground fault occurs at R.

[0060] The application can greatly improve the strength of the injected signal by using the vehicle-mounted power output device to send back electricity, and can realize fast and accurate positioning of the single-phase ground fault point of the power distribution network by cooperating with the unmanned aerial vehicle carrying electric field and magnetic field sensors, thereby improving the reliability of power supply.

[0061] In summary, by using the vehicle-mounted current output device to send back electricity in combination with the distribution transformer, the amplitude of the injected signal is strengthened, and the signal-to-noise ratio is maximized. When positioning the single-phase ground fault of the power distribution network in cooperation with the unmanned aerial vehicle, the electric field sensor and the magnetic field sensor are used to capture the fault signal (injected current and voltage), and the ratio coefficient is used to distinguish the position of the fault point. During the entire maintenance process, there is no need for manual climbing and wiring, and only remote control of the unmanned aerial vehicle is needed for non-contact measurement, thereby reducing the working difficulty of the inspection personnel, improving the inspection efficiency, and better protecting the safety of the inspection personnel.

[0062] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the application and is not intended to limit the application, and any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A method for locating a single-phase ground fault in an overhead line of a distribution network, characterized in that: include: After a single-phase grounding fault occurs on an overhead line of a distribution network, an AC voltage and a current are simultaneously injected into the overhead line under test, and the AC voltage and current generate electric and magnetic fields on the overhead line under test; And collect the electric field signal and magnetic field signal on the overhead line under test; Calculating the instantaneous voltage value and the instantaneous current value at different positions on the overhead line under test based on the electric field signal and the magnetic field signal; and calculating the full-cycle Fourier amplitude of the instantaneous voltage value and the instantaneous current value; Integrating the product of the instantaneous value of the voltage and the instantaneous value of the current within one electric field or magnetic field alternating cycle to obtain integral values ​​at different positions on the measured overhead line; The integral value is divided by the product of the full-cycle Fourier amplitude of the instantaneous value of the voltage and the instantaneous value of the current to obtain the ratio coefficient at different positions on the measured overhead line, so as to construct a function of the ratio coefficient between different positions on the measured overhead line; wherein, a single-phase grounding fault occurs at the position corresponding to the maximum value of the first-order derivative of the function.

2. The method for locating a single-phase grounding fault in an overhead line of a distribution network according to claim 1, wherein: Simultaneously inject AC voltage and current into the overhead line under test, including: The battery and inverter are mounted on a maintenance vehicle. The inverter converts the DC voltage and current generated by the battery into AC voltage and current, which are then transmitted to a distribution transformer via a high-voltage cable for voltage boosting. The boosted AC voltage and current are injected into the overhead line under test. The electric field signal and magnetic field signal are collected by electric field sensors and magnetic field sensors mounted on a drone.

3. The method for locating a single-phase grounding fault in an overhead line of a distribution network according to claim 2, wherein: The frequency of the AC current generated by the inverter is 60HZ-100HZ.

4. A single-phase ground fault location system for overhead lines in a distribution network, characterized in that: include: A signal injection module is used to simultaneously inject AC voltage and current into the overhead line under test after a single-phase grounding fault occurs on the overhead line of the distribution network. The AC voltage and current generate electric and magnetic fields on the overhead line under test; Electric field sensor, used to collect electric field signals on the overhead line under test; A magnetic field sensor is used to collect magnetic field signals on the overhead line under test; a fault identification module, configured to calculate, based on the electric field signal and the magnetic field signal, the instantaneous voltage value and the instantaneous current value at different positions on the overhead line under test, and to calculate the full-cycle Fourier amplitude of the instantaneous voltage value and the instantaneous current value; and to integrate the product of the instantaneous voltage value and the instantaneous current value within one electric field or magnetic field alternation cycle to obtain the integral value at different positions on the overhead line under test; The integral value is divided by the product of the full-cycle Fourier amplitude of the instantaneous value of the voltage and the instantaneous value of the current to obtain the ratio coefficient at different positions on the measured overhead line, so as to construct a function of the ratio coefficient between different positions on the measured overhead line; wherein, a single-phase grounding fault occurs at the position corresponding to the maximum value of the first-order derivative of the function.

5. The distribution network overhead line single-phase grounding fault location system according to claim 4, characterized in that: It also includes a drone for carrying the electric field sensor and the magnetic field sensor; and the signal injection module includes a battery and an inverter mounted on the maintenance vehicle; The inverter is used to invert the DC voltage and current generated by the battery into AC voltage and current; wherein, the AC voltage and current are transmitted to the distribution transformer through a high-voltage cable for boosting, and the boosted AC voltage and current are injected into the overhead line under test.

6. The distribution network overhead line single-phase grounding fault location system according to claim 5, characterized in that: Also included is a communication unit carried on the drone; The communication unit is used to receive and store the electric field signals and magnetic field signals collected by the electric field sensor and the magnetic field sensor, and send the electric field signals and magnetic field signals to the fault identification module.

7. The distribution network overhead line single-phase grounding fault location system according to claim 4 or 5, characterized in that: The electric field sensor is a three-dimensional electric field vector sensor with a six-electrode structure having arc surfaces equally divided.

8. The distribution network overhead line single-phase grounding fault location system according to claim 4 or 5, characterized in that: The magnetic field sensor is a giant magneto-impedance sensor.

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