Three-dimensional partial discharge location method for ac transmission line based on unmanned aerial vehicle on-board eight-quadrant broadband high-frequency electric field vector probe
Patent Information
- Application Number
- CN202611411460.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-09-11
- Publication Date
- 2026-10-20
AI Technical Summary
但该磁场阵列TDOA定位方案存在多重固有缺陷：磁场天线具备明显方向性，存在检测盲区，易出现阵列部分天线信号缺失、定位方程无解；且TDOA定位精度高度依赖大间距阵列基线与多通道高精度同步采样，大尺寸阵列无法适配无人机轻量化挂载需求，无人机紧凑阵列布置方式会因基线不足导致时差分辨率大幅下降，定位精度严重劣化，难以实现输电线路断股、绝缘子局部放电的高精度、高适配性定位
[0026]本发明的有益效果在于：与传统依赖紫外、可见光、红外、超声或射频强度定位的方法不同，本发明利用局部放电瞬态电荷释放所引起的电场扰动作为定位信息源。由于局部放电单次放电量具有随机性，直接利用信号幅值反推距离容易产生较大误差。本发明通过构造对置电极差分量，优先提取电场方向信息，从而在一定程度上削弱局部放电幅值波动、无人机自身带电、工频背景电场和环境噪声对测向结果的影响。进一步地，结合无人机在巡检过程中的多个观测位置和姿态信息，通过多方向射线交汇获得局部放电点的三维空间位置。
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of power transmission line inspection technology, and relates to a three-dimensional localization method for partial discharge of AC power transmission lines based on an airborne eight-quadrant broadband high-frequency electric field vector probe from an unmanned aerial vehicle. Background Technology
[0002] During UAV inspections of power transmission lines, detection methods such as high-frequency electric fields, ultraviolet light, or ultrasound can be used to detect partial discharge anomalies. However, merely confirming the presence of a discharge signal is insufficient to pinpoint the exact spatial location of the discharge source within the conductor, fittings, insulator, or its connection points. Existing positioning methods based on high-frequency electromagnetic signals typically employ multiple spatially separated sensors and estimate the location of the partial discharge source using signal arrival time difference, phase difference, or array pattern. Their positioning accuracy depends on the sensor array baseline, multi-channel synchronization accuracy, and antenna directional characteristics. Due to limitations in UAV payload and installation space, the array spacing cannot be fully deployed, easily leading to insufficient time difference resolution, ill-conditioned positioning equations, and direction-finding blind zones.
[0003] In existing technologies for inspecting and detecting partial discharge on high-voltage AC transmission lines using drones, ultraviolet imaging and ultrasonic detection are susceptible to environmental interference, and their safe detection distance is severely limited. Ultra-high frequency (UHF) detection technology, by collecting high-frequency electromagnetic wave signals (300MHz–3GHz) emitted by partial discharge, offers advantages such as long propagation distance, resistance to low-frequency interference, and compatibility with non-contact drone inspections, making it the core technology for online inspection of partial discharge on transmission lines. This technology relies on the principle of synchronous acquisition using a multi-sensor array and employs a Time Difference of Arrival (TDOA) algorithm to achieve spatial positioning of the partial discharge source. This is currently the mainstream technical approach for precise positioning of UHF partial discharge. The positioning principle utilizes the nanosecond-level time difference in the propagation of the partial discharge electromagnetic wave to different antennas to construct a spatial equation system to solve for the defect coordinates. Currently, the industry mainstream uses magnetic loop antennas to pick up the magnetic field components of the partial discharge. Leveraging their natural shielding against power frequency electric field interference, lightweight design, and compatibility with mobile inspections, they are widely used in outdoor transmission line inspections. However, the magnetic field array TDOA positioning scheme has several inherent defects: the magnetic field antenna has obvious directionality, there is a detection blind zone, and it is easy for some antennas in the array to lose signals and the positioning equation has no solution; moreover, the positioning accuracy of TDOA is highly dependent on the large-spacing array baseline and multi-channel high-precision synchronous sampling. The large-size array cannot adapt to the lightweight payload requirements of UAVs, and the compact array arrangement of UAVs will cause a significant decrease in time difference resolution due to insufficient baseline, resulting in serious deterioration of positioning accuracy, making it difficult to achieve high-precision and highly adaptable positioning of power transmission line strand breakage and insulator partial discharge. Summary of the Invention
[0004] In view of this, the purpose of this invention is to provide a three-dimensional localization method for partial discharge of AC transmission lines based on an airborne eight-quadrant broadband high-frequency electric field vector probe from an unmanned aerial vehicle.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A three-dimensional localization method for partial discharge in AC transmission lines based on an UAV-borne eight-quadrant broadband high-frequency electric field vector probe includes the following steps: S1: Equip an eight-quadrant broadband high-frequency electric field vector probe on a drone to inspect AC transmission lines; S2: After the broadband high-frequency electric field pulse generated by partial discharge acts on the probe, it forms a spatially differentiated inductive response on the eight zone electrodes; S3: By constructing half-space difference components along three orthogonal directions, the common power frequency background and low-frequency common-mode interference of the eight channels are suppressed, the three equivalent orthogonal components of the high-frequency electric field of partial discharge in the probe coordinate system are recovered, and the original direction finding vector, azimuth angle and polar angle are calculated. S4: Combining the probe calibration relationship, the UAV's spatial position, and the direction finding rays obtained from multiple observation positions, the three-dimensional spatial position of the local discharge source is solved by spatial intersection.
[0006] Furthermore, the eight-quadrant broadband high-frequency electric field vector probe includes an insulating support body. Eight electrically isolated independent electric field sensing electrodes are arranged around the geometric center of the probe on the outer surface of the insulating support body. Each electrode is located in the corresponding region of the eight quadrants defined by three mutually orthogonal dividing planes. Each electrode is connected to an independent high input impedance charge conditioning channel and a transimpedance amplification channel. Each channel is synchronously acquired using a common sampling clock, and the differences in channel gain, fixed delay, and phase response are calibrated and compensated.
[0007] Furthermore, the responses of the eight zoned electrodes to high-frequency electric fields in three orthogonal directions can be obtained through electromagnetic simulation or standard electric field calibration; the eight-channel outputs are used to construct a response vector, which has a linear calibration relationship with the three-axis high-frequency electric field components in the probe coordinate system. The measured charge response of the eight channels is as follows:
[0008] in, The measured charge response vector is... For background components, This represents the noise component.
[0009] Furthermore, the high input impedance charge conditioning channel includes one or more of the following: charge amplification, transimpedance conversion, bandpass filtering, gain adjustment, and analog-to-digital conversion; under ideal symmetry conditions, the first... i The charge response of each electrode is written as:
[0010] in, , , These are the equivalent sensitivity coefficients of the probe to electric fields in three directions. The power frequency background and low-frequency common-mode components are approximately shared by all eight channels. For the first i Channel noise.
[0011] Furthermore, the construction of half-space difference components along three orthogonal directions suppresses the common power frequency background and low-frequency common-mode interference shared by the eight channels, and restores the three equivalent orthogonal components of the partial discharge high-frequency electric field in the probe coordinate system, including: Constructing a probe axis, axis, Half-space difference components:
[0012] Substitute the responses of the eight electrodes into the above equation. , and common mode background Because the positive and negative signs cancel each other out, we get:
[0013] in, , , for , , Equivalent noise after axis differential; three orthogonal components of the transient electric field of partial discharge estimated from three sets of half-space difference components:
[0014] This yields the estimated value of the transient electric field vector of partial discharge in the probe coordinate system:
[0015] Normalizing it yields the unit vector of the electric field direction: .
[0016] Furthermore, the direction of the high-frequency transient electric field vector recovered by the eight-quadrant probe is used as the original direction-finding vector of the partial discharge source. Under the condition that the point charge is equivalent or the radial electric field component is dominant, the original direction-finding vector approximately represents the direction of the partial discharge source. When the influence of the equipment structure on the local electric field distribution is significant, the original direction-finding vector is corrected through probe orientation calibration, equipment structure response correction, or multi-position observation consistency correction. The original direction-finding vector of partial discharge in the probe coordinate system is:
[0017] in, sThe polarity symbol is used. The azimuth angle of the original direction-finding vector in the probe coordinate system is expressed as:
[0018] The polar angle of the original direction-finding vector in the probe coordinate system is expressed as:
[0019] in, This is the four-quadrant arctangent function, used to avoid quadrant ambiguity caused by the ordinary arctangent function.
[0020] Furthermore, in step S4, based on the probe's installation matrix and the UAV's flight attitude, the original direction finding vector in the probe coordinate system or the direction finding direction vector after direction calibration, equipment structure response correction and multi-position observation consistency correction is converted into an absolute direction vector in the geographic coordinate system, and then used for subsequent spatial ray intersection positioning. Suppose the drone is in the... k The positions at each observation time are:
[0021] No. k At each observation time, the location of the local discharge power source It should be located at the location of the drone. , direction is On the space ray:
[0022] in, For unknown distance parameters; Construct the projection matrix:
[0023] in, It is a three-dimensional identity matrix; point To the k The perpendicularity error of the directional ray is The location of the local power source was obtained through the following weighted least squares problem:
[0024] in, N The number of observation locations involved in the positioning. For the first k Weights for each observation direction; weights The determination is based on the partial discharge pulse signal-to-noise ratio, directional stability, UAV attitude stability, eight-channel consistency, direction finding residual, and equipment geometric constraint consistency. When matrix When the rank is full or the condition number meets the threshold requirement, a closed-form solution is used; when the angle between the observed rays is too small or the matrix is ill-conditioned, new observation positions are collected or geometric constraints of the equipment are introduced; the closed-form solution of the least squares problem is:
[0025] This formula represents the three-dimensional localization result of partial discharge based on an external three-dimensional eight-quadrant electric field vector probe.
[0026] The beneficial effects of this invention are as follows: Unlike traditional methods that rely on ultraviolet, visible light, infrared, ultrasound, or radio frequency intensity for positioning, this invention utilizes the electric field disturbance caused by the transient charge release of partial discharge as the positioning information source. Since the amount of a single partial discharge is random, directly using the signal amplitude to extrapolate the distance can easily lead to significant errors. This invention constructs a differential component between opposing electrodes to prioritize the extraction of electric field direction information, thereby mitigating to some extent the influence of partial discharge amplitude fluctuations, the UAV's own charge, the power frequency background electric field, and environmental noise on the direction finding results. Furthermore, by combining multiple observation positions and attitude information from the UAV during the inspection process, the three-dimensional spatial location of the partial discharge point is obtained through multi-directional ray convergence.
[0027] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description
[0028] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 It is a three-dimensional electric field vector probe; Figure 2 This is a schematic diagram of the eight-quadrant half-space differential signal decoupling principle. Figure 3 This is a schematic diagram illustrating the spatial convergence and positioning of drones at multiple locations. Figure 4 This is a flowchart of a three-dimensional orientation and localization method for partial discharge. Detailed Implementation
[0029] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0030] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0031] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.
[0032] Example 1: This invention proposes a three-dimensional localization method for partial discharge in AC transmission lines based on an airborne eight-quadrant broadband high-frequency electric field vector probe from an unmanned aerial vehicle (UAV). The probe includes an insulating support, eight independent electric field induction electrodes distributed across eight spatial regions defined by three orthogonal partitioning planes, an eight-channel broadband high-input-impedance signal conditioning unit, and a synchronous acquisition unit. When the broadband high-frequency electric field pulse generated by the partial discharge acts on the probe, it forms spatially differentiated inductive responses on the eight partitioned electrodes. By constructing half-spatial difference components along three orthogonal directions, the common power frequency background and low-frequency common-mode interference of the eight channels are suppressed, restoring the three equivalent orthogonal components of the high-frequency electric field of the partial discharge in the probe coordinate system, and calculating the original direction-finding vector, azimuth angle, and polar angle. Furthermore, by combining the probe calibration relationship, the UAV's spatial position, and direction-finding rays obtained from multiple observation positions, the three-dimensional position of the partial discharge source is solved through spatial convergence.
[0033] This invention employs a three-dimensional electric field vector probe independently mounted on a drone platform. The probe can be mounted at the front of the drone's nose, at the end of an insulating bracket, or suspended below the drone via an insulating connector. First, the corresponding three-dimensional electric field vector probe is as follows: Figure 1 As shown.
[0034] The insulating support can be ellipsoidal, spherical, or other centrosymmetric structures, and its characteristic dimensions in the three orthogonal directions are respectively... a p , b p , c p Eight electrically isolated zone electrodes are arranged around the geometric center of the probe on the outer surface of the insulating support body. Each zone electrode is located in a region corresponding to one of the eight quadrants defined by three mutually orthogonal dividing planes. Each electrode may cover all or part of the surface of its corresponding quadrant, and is not required to form a completely closed ellipsoidal conductor. The corresponding electrode responses are denoted as follows:
[0035] Insulating gaps are set between the eight electrodes to electrically isolate them from each other, without forming a complete closed conductor shield. Each electrode is connected to an independent high input impedance charge conditioning channel and a transimpedance amplification channel to ensure that the transient electric field of partial discharge can form a distinguishable induced charge response on different zone electrodes. All channels are synchronously acquired using a common sampling clock, and the differences in channel gain, fixed delay, and phase response are calibrated and compensated.
[0036] The high-frequency transient electric field generated by partial discharge exhibits differentiated responses in different spatial directions. This invention does not directly invert the distance based on the absolute amplitude of the partial discharge signal. Instead, it extracts the spatial direction characteristics of the high-frequency electric field at the probe through the relative responses of eight zone electrodes, and obtains the direction finding results of the partial discharge source through calibration relationships.
[0037] The responses of the eight partitioned electrodes to high-frequency electric fields in three orthogonal directions can be obtained through electromagnetic simulation or standard electric field calibration. Due to the spatial symmetry of the eight-quadrant structure about the three orthogonal dividing planes, electric field components in different directions will produce differentiated responses on opposite electrodes. Constructing the response vector from the eight channel outputs, its relationship with the three-axis high-frequency electric field components in the probe coordinate system can be expressed as a linear calibration relationship. Considering power frequency background, the UAV's own charge, sensor zero drift, and noise, the measured charge response of the eight channels is:
[0038] in, The measured charge response vector is... For background components, This represents the noise component. Each partition electrode is connected to an independent broadband high input impedance signal conditioning channel, which may include one or more of the following: charge amplification, transimpedance conversion, bandpass filtering, gain adjustment, and analog-to-digital conversion. All channels use a common sampling clock and are calibrated to compensate for differences in gain, fixed delay, and phase response.
[0039] Under ideal symmetry conditions, the first i The charge response of each electrode can be approximated as:
[0040] in, , , These are the equivalent sensitivity coefficients of the probe to electric fields in three directions. The power frequency background and low-frequency common-mode components are approximately shared by all eight channels. For the first i Channel noise.
[0041] Constructing a probe axis, axis, Half-space difference components:
[0042] Substitute the responses of the eight electrodes into the above equation. , and common mode background Because of their symmetry, they cancel each other out, which gives us:
[0043] in, , , for , , The equivalent noise after axis differential. Therefore, the three orthogonal components of the transient electric field of partial discharge can be estimated from the three sets of half-space difference components:
[0044] This yields the estimated value of the transient electric field vector of partial discharge in the probe coordinate system:
[0045] Normalizing it yields the unit vector of the electric field direction:
[0046] The direction of the high-frequency transient electric field vector recovered by the eight-quadrant probe is used as the original direction-finding vector of the partial discharge source. Under the condition that the point charge is equivalent or the radial electric field component is dominant, the original direction-finding vector can approximately characterize the direction of the partial discharge source. When the structure of equipment such as conductors, fittings, and insulators has a significant impact on the local electric field distribution, the original direction-finding vector can be corrected through probe orientation calibration, equipment structure response correction, or multi-position observation consistency correction. Therefore, the original direction-finding vector of partial discharge in the probe coordinate system is:
[0047] in, s The polarity symbol is used. The azimuth angle of the original direction-finding vector in the probe coordinate system can be expressed as:
[0048] The polar angle of the original direction-finding vector in the probe coordinate system can be expressed as:
[0049] in, This is the four-quadrant arctangent function, used to avoid quadrant ambiguity caused by the ordinary arctangent function.
[0050] The corresponding spatial difference and signal decoupling principle diagram is as follows: Figure 2 As shown.
[0051] A single observation location can only obtain the direction of the partial discharge source relative to the probe, and cannot directly obtain the distance to the partial discharge source. Because the single discharge magnitude and transient electric field amplitude of partial discharge have random fluctuation characteristics, it is not appropriate to rely solely on signal amplitude to invert the distance. This invention utilizes multiple observation locations formed by a UAV during inspection for spatial convergence positioning. Based on the probe's installation matrix and the UAV's flight attitude, the original direction-finding vector in the probe coordinate system, or the direction-finding direction vector after direction calibration, equipment structure response correction, and multi-location observation consistency correction, is converted into an absolute direction vector in the geographic coordinate system, and then used for subsequent spatial ray convergence positioning, such as... Figure 3 As shown.
[0052] Suppose the drone is in the... k The positions at each observation time are:
[0053] No. k At each observation time, the location of the local discharge power source It should be located at the location of the drone. , direction is On the space ray:
[0054] in, The distance parameter is unknown. Due to measurement noise, model errors, and attitude errors, multiple direction-finding rays typically do not intersect precisely. Therefore, the projection matrix is constructed as follows:
[0055] in, It is a three-dimensional identity matrix.
[0056] point To the kThe perpendicularity error of the directional ray is The location of the local power source can be obtained through the following weighted least squares problem:
[0057] in, N The number of observation locations involved in the positioning. For the first k Weights for each observation direction. It can be determined based on the partial discharge pulse signal-to-noise ratio, directional stability, UAV attitude stability, eight-channel consistency, direction finding residual, and equipment geometric constraint consistency.
[0058] When matrix When the rank is full or the condition number meets the threshold requirement, a closed-form solution can be used; when the angle between the observed rays is too small or the matrix is ill-conditioned, new observation positions should be acquired or geometric constraints on the equipment should be introduced. The closed-form solution to the above least squares problem is:
[0059] This formula represents the three-dimensional localization result of partial discharge based on an external three-dimensional eight-quadrant electric field vector probe.
[0060] The overall process of this method is as follows: Figure 4 As shown.
[0061] Example 2: An electronic device, comprising a memory and a processor; The memory is used to store computer programs; The processor is configured to implement the method described in Embodiment 1 when executing the computer program.
[0062] Example 3: A computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in Embodiment 1.
[0063] Example 4: A computer program product includes a computer program that, when executed by a processor, implements the method described in Example 1.
[0064] In the above embodiments, the reference to "this embodiment" in the specification indicates that a specific feature, structure, or characteristic described in connection with the embodiment is included in at least some embodiments, but not necessarily all embodiments. Multiple appearances of "this embodiment" do not necessarily all refer to the same embodiment.
[0065] In the above embodiments, although the invention has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory structures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed. The embodiments of the invention are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims.
[0066] As will be understood by those skilled in the art, the computer-readable storage medium described in this embodiment allows for the implementation of all or part of the steps in the above method embodiments by computer program-related hardware. The aforementioned computer program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.
[0067] The electronic terminal provided in this embodiment includes a processor, a memory, a transceiver, and a communication interface. The memory and the communication interface are connected to the processor and the transceiver and complete communication between them. The memory is used to store computer programs, the communication interface is used to perform communication, and the processor and the transceiver are used to run the computer programs, so that the electronic terminal performs the steps of the above method.
[0068] In this embodiment, the memory may include random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device.
[0069] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.
[0070] This invention can be used in a wide range of general-purpose or special-purpose computing system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.
[0071] This invention can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This invention can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.
[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A three-dimensional localization method for partial discharge in AC transmission lines based on an UAV-borne eight-quadrant broadband high-frequency electric field vector probe, characterized in that: Includes the following steps: S1: Equip an eight-quadrant broadband high-frequency electric field vector probe on a drone to inspect AC transmission lines; S2: After the broadband high-frequency electric field pulse generated by partial discharge acts on the probe, it forms a spatially differentiated inductive response on the eight zone electrodes; S3: By constructing half-space difference components along three orthogonal directions, the common power frequency background and low-frequency common-mode interference of the eight channels are suppressed, the three equivalent orthogonal components of the high-frequency electric field of partial discharge in the probe coordinate system are recovered, and the original direction finding vector, azimuth angle and polar angle are calculated. S4: Combining the probe calibration relationship, the UAV's spatial position, and the direction finding rays obtained from multiple observation positions, the three-dimensional spatial position of the local discharge source is solved by spatial intersection.
2. The method for three-dimensional localization of partial discharge in AC transmission lines based on an airborne eight-quadrant broadband high-frequency electric field vector probe of an unmanned aerial vehicle (UAV) as described in claim 1, characterized in that: The eight-quadrant broadband high-frequency electric field vector probe includes an insulating support body. Eight electrically isolated independent electric field sensing electrodes are arranged around the geometric center of the probe on the outer surface of the insulating support body. Each electrode is located in the corresponding region of the eight quadrants defined by three mutually orthogonal dividing planes. Each electrode is connected to an independent high input impedance charge conditioning channel and a transimpedance amplification channel. All channels are synchronously acquired using a common sampling clock, and the differences in channel gain, fixed delay, and phase response are calibrated and compensated.
3. The method for three-dimensional localization of partial discharge in AC transmission lines based on an UAV-borne eight-quadrant broadband high-frequency electric field vector probe according to claim 1, characterized in that: The responses of the eight zoned electrodes to high-frequency electric fields in three orthogonal directions can be obtained through electromagnetic simulation or standard electric field calibration. The eight-channel outputs are used to construct a response vector, which has a linear calibration relationship with the three-axis high-frequency electric field components in the probe coordinate system. The measured charge response of the eight channels is as follows: in, The measured charge response vector is... For background components, This represents the noise component.
4. The method for three-dimensional localization of partial discharge in AC transmission lines based on an UAV-borne eight-quadrant broadband high-frequency electric field vector probe according to claim 1, characterized in that: The high input impedance charge conditioning channel includes one or more of the following: charge amplification, transimpedance conversion, bandpass filtering, gain adjustment, and analog-to-digital conversion; under ideal symmetry conditions, the first... i The charge response of each electrode is written as: in, , , These are the equivalent sensitivity coefficients of the probe to electric fields in three directions. The power frequency background and low-frequency common-mode components are approximately shared by all eight channels. For the first i Channel noise.
5. The method for three-dimensional localization of partial discharge in AC transmission lines based on an airborne eight-quadrant broadband high-frequency electric field vector probe of an unmanned aerial vehicle (UAV) as described in claim 1, characterized in that: The structure, with its half-space difference components along three orthogonal directions, suppresses the common power frequency background and low-frequency common-mode interference shared by the eight channels, and restores the three equivalent orthogonal components of the partial discharge high-frequency electric field in the probe coordinate system, including: Constructing a probe axis, axis, Half-space difference components: Substitute the responses of the eight electrodes into the above equation. , and common mode background Because the positive and negative signs cancel each other out, we get: in, , , for , , Equivalent noise after axis differential; three orthogonal components of the transient electric field of partial discharge estimated from three sets of half-space difference components: This yields the estimated value of the transient electric field vector of partial discharge in the probe coordinate system: Normalizing it yields the unit vector of the electric field direction: 。 6. The method for three-dimensional localization of partial discharge in AC transmission lines based on an UAV-borne eight-quadrant broadband high-frequency electric field vector probe according to claim 1, characterized in that: The direction of the high-frequency transient electric field vector recovered by the eight-quadrant probe is used as the original direction-finding vector of the partial discharge source. Under the condition that the point charge is equivalent or the radial electric field component is dominant, the original direction-finding vector approximately represents the direction of the partial discharge source. When the equipment structure has a significant impact on the local electric field distribution, the original direction-finding vector is corrected through probe orientation calibration, equipment structure response correction, or multi-position observation consistency correction. The original direction-finding vector of partial discharge in the probe coordinate system is: in, s The polarity symbol is used; the azimuth angle of the original direction-finding vector in the probe coordinate system is expressed as: The polar angle of the original direction-finding vector in the probe coordinate system is expressed as: in, This is the four-quadrant arctangent function, used to avoid quadrant ambiguity caused by the ordinary arctangent function.
7. The method for three-dimensional localization of partial discharge in AC transmission lines based on an airborne eight-quadrant broadband high-frequency electric field vector probe of an unmanned aerial vehicle (UAV) as described in claim 1, characterized in that: In step S4, based on the probe's installation matrix and the UAV's flight attitude, the original direction finding vector in the probe coordinate system or the direction finding direction vector after direction calibration, equipment structure response correction and multi-position observation consistency correction is converted into an absolute direction vector in the geographic coordinate system, and then used for subsequent spatial ray intersection positioning. Suppose the drone is in the 1st k The positions at each observation time are: No. k At each observation time, the location of the local discharge power source It should be located at the location of the drone. , direction is On the space ray: in, For unknown distance parameters; Construct the projection matrix: in, It is a three-dimensional identity matrix; point To the k The perpendicularity error of the direction-finding ray is The location of the local power source was obtained through the following weighted least squares problem: in, N The number of observation locations involved in the positioning. For the first k Weights for each observation direction; weights The determination is based on the partial discharge pulse signal-to-noise ratio, directional stability, UAV attitude stability, eight-channel consistency, direction finding residual, and equipment geometric constraint consistency. When matrix When the rank is full or the condition number meets the threshold requirement, a closed-form solution is used; when the angle between the observed rays is too small or the matrix is ill-conditioned, new observation positions are collected or geometric constraints of the equipment are introduced; the closed-form solution of the least squares problem is: This formula represents the three-dimensional localization result of partial discharge based on an external three-dimensional eight-quadrant electric field vector probe.