Method and system for measuring surface charge density of an insulating pull rod

Abstract

The application relates to the technical field of charge density measurement, and particularly provides a kind of insulating pull rod surface charge density measurement method and system.The method comprises the following steps: fixing the insulating pull rod to be measured on a rotating platform, so that the axis of the insulating pull rod to be measured coincides with the rotating axis of the platform and the two ends of the insulating pull rod to be measured are grounded; a driving mechanism drives the platform to rotate at a constant speed, and a detection probe perpendicular to the axis of the pull rod collects surface potential data at a preset sampling frequency; a linear displacement platform drives the probe to move step by step along the axial direction of the pull rod, and after traversing the full length, all potential data are obtained and a potential distribution matrix is constructed; and the surface charge density distribution vector of the insulating pull rod is obtained by solving in combination with the linear conversion coefficient matrix of the potential and the charge.The insulating pull rod surface charge density measurement method and system provided by the application can solve the problem that related measurement methods cannot meet the axial and circumferential composite scanning requirements of the cylindrical surface of the insulating pull rod, it is difficult to stably maintain the measurement interval, and the automation is insufficient.

Description

Technical Field

[0001] This invention relates to the field of charge density measurement technology, and in particular to a method and system for measuring the surface charge density of an insulating tie rod. Background Technology

[0002] The insulating tie rod is a critical power transmission component between the operating mechanism and the arc-extinguishing chamber of a GIS circuit breaker, and the stability of its insulation performance directly affects the safe operation of the entire switchgear. With the increase in GIS voltage levels and the compactness of its structure, the internal electric field is strengthened, exacerbating the problems of surface charge accumulation and uneven electric field distribution on the insulating tie rod. This easily distorts the electric field, reduces surface flashover voltage, and induces insulation faults. Therefore, accurate measurement of the surface charge distribution of the insulating tie rod is crucial for assessing the insulation condition and improving the safety and reliability of the equipment.

[0003] Currently, the Kelvin probe active probe method is the most widely used for measuring surface charge on solid insulation. However, existing measurement devices are mostly designed for the disc-shaped structure of basin insulators. Their motion control and scanning modes cannot be adapted to the axial and circumferential composite scanning requirements of the slender cylindrical curved surface of GIS insulating rods. It is difficult to stably maintain the normal measurement distance between the probe and the curved surface, which means that it is impossible to complete effective measurement by directly using existing technology. Dedicated measurement devices are not yet perfect, and the measurement process mostly relies on manual debugging, with insufficient levels of automation and standardization.

[0004] There are currently no effective solutions to the problems that related technologies cannot meet the requirements of axial and circumferential composite scanning of the cylindrical curved surface of the insulating tie rod, are difficult to maintain a stable measurement interval, and lack automation. Summary of the Invention

[0005] The present invention provides a method and system for measuring the surface charge density of an insulating tie rod, which at least solves the problems that related technologies cannot meet the requirements of axial and circumferential composite scanning of the cylindrical curved surface of an insulating tie rod, are difficult to maintain a stable measurement interval, and lack automation.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The first aspect of this invention provides a method for measuring the surface charge density of an insulating tie rod. The method includes: fixing the insulating tie rod to be measured on a rotating platform such that the axis of the insulating tie rod coincides with the rotation axis of the rotating platform, and grounding both ends of the insulating tie rod; controlling the rotating platform to rotate at a uniform speed through a driving mechanism, while a detection probe arranged perpendicular to the axis of the insulating tie rod collects potential data of the surface of the insulating tie rod at a preset sampling frequency; driving the detection probe to move stepwise along the axis of the insulating tie rod through a linear displacement platform until the detection probe traverses the entire axial length of the insulating tie rod, obtaining all potential data of the surface of the insulating tie rod, and constructing a potential distribution matrix; wherein, the rotating platform stops rotating when the detection probe moves, and the rotating platform rotates one revolution when the detection probe is stationary; and solving for the charge density distribution vector of the surface of the insulating tie rod based on the potential distribution matrix and the coefficient matrix of linear conversion between potential and charge; wherein, the coefficient matrix is ​​obtained by simulation calculation of each cylindrical surface micro-element of the surface of the insulating tie rod using the unit charge method.

[0008] Preferably, before fixing the insulating rod to be tested to the rotating platform, the method includes: fixing a linear displacement platform to a grounded platform via a column; wherein the linear displacement platform includes: a slider, a guide rail, and a displacement driving component for driving the slider to move along the guide rail; the moving direction of the slider is a first direction; fixing a detection probe to the slider such that the arrangement direction of the detection probe is perpendicular to the first direction, and connecting the output end of the detection probe to an electrometer via a shielded cable; fixing a rotating platform to the grounded platform, and the rotation axis of the rotating platform is parallel to the first direction.

[0009] Preferably, fixing the insulating rod to be tested on a rotating platform, such that the axis of the insulating rod coincides with the rotation axis of the rotating platform, and grounding both ends of the insulating rod, includes: fixing the insulating rod to be tested on the rotating platform, such that the insulating rod is positioned between the detection probe and the grounding platform, and that the axis of the insulating rod coincides with the rotation axis of the rotating platform; adjusting the distance between the tip of the detection probe and the surface of the insulating rod, such that the distance reaches a preset fixed distance; and connecting both ends of the insulating rod to the grounding platform through two wires.

[0010] Preferably, the detection probe is driven to move stepwise along the axial direction of the insulating rod by a linear displacement platform until the detection probe traverses the entire axial length of the insulating rod, obtaining all potential data on the surface of the insulating rod, and constructing a potential distribution matrix. This includes: after each rotation of the insulating rod, the linear displacement platform drives the detection probe to advance one preset step length along the axial direction of the insulating rod, and the rotating platform stops rotating while the detection probe moves; until the detection probe traverses the entire axial length of the insulating rod, obtaining all potential data on the surface of the insulating rod; and the all potential data, based on the axial movement position corresponding to each advance of the detection probe and the circumferential sampling position corresponding to one rotation of the insulating rod, are arranged in an orderly manner in two dimensions, axial and circumferential, to construct a potential distribution matrix.

[0011] Preferably, before solving for the charge density distribution vector on the surface of the insulating rod, the method includes: constructing a three-dimensional electrostatic field simulation model that matches the actual measurement conditions of the insulating rod based on its geometric dimensions and material properties; uniformly dividing the cylindrical surface of the insulating rod in the three-dimensional electrostatic field simulation model into several cylindrical surface micro-elements according to the axial and circumferential two-dimensional dimensions, and setting the two ends of the insulating rod as grounded boundary conditions; sequentially applying a preset unit charge to each of the cylindrical surface micro-elements, while keeping the remaining cylindrical surface micro-elements with zero charge; and solving for the potential values ​​generated by the preset unit charge at all the cylindrical surface micro-elements based on the principle of linear superposition of electrostatic fields; and arranging the potential values ​​corresponding to each of the cylindrical surface micro-elements according to the two-dimensional indexes in the axial and circumferential directions to obtain a coefficient matrix for the linear conversion of potential and charge.

[0012] Preferably, the formula for calculating the charge density distribution vector on the surface of the insulating tie rod is: ; ;in, for The charge density distribution vector of order; for The coefficient matrix of order M and N represents the number of cylindrical surface elements in the axial and circumferential directions, respectively. The potential distribution matrix is ​​obtained by expansion A column vector of potential distributions of order 1; This is a block matrix in the nth row and mth column of the coefficient matrix. ; The block matrix is Square matrix; for The matrix element in row s and column t represents the axis of the t-th column. One, Zhou Xiangdi A preset unit charge is applied at the position of the infinitesimal element of the cylindrical surface, and in the axial direction... One, Zhou Xiangdi The potential value generated at the position of a cylindrical curved surface micro-element; The axial index of the cylindrical surface micro-element is used as the excitation micro-element. Let the circumferential index of the cylindrical surface infinitesimal element be used as the excitation infinitesimal element, and the total excitation index be... , ; The cylindrical surface element is used as the axial index of the observed element. The cylindrical surface infinitesimal element is used as the circumferential index of the observation infinitesimal element, and the total observation index is... , .

[0013] A second aspect of the present invention provides a system for measuring the surface charge density of an insulating tie rod, applied to the aforementioned method for measuring the surface charge density of an insulating tie rod. The system includes: a grounding platform and a linear displacement platform, a rotating platform, a driving mechanism, and a control system mounted on the grounding platform; a slider is movably mounted on the linear displacement platform, the slider moving in a first direction; the rotating platform is used to mount the insulating tie rod to be measured, such that the axis of the insulating tie rod coincides with the rotation axis of the rotating platform and is parallel to the first direction; a detection probe is mounted on the slider, the detection probe being arranged perpendicular to the first direction, for collecting potential data of the surface of the insulating tie rod; the driving mechanism is connected to the rotating platform for driving the rotating platform... The platform rotates along the rotation axis; the control system is connected to the linear displacement platform and the drive mechanism, and is used to control the linear displacement platform to drive the detection probe to move stepwise along the axial direction of the insulating rod until the detection probe traverses the entire axial length of the insulating rod, obtains all potential data of the surface of the insulating rod, and constructs a potential distribution matrix; wherein, when the detection probe moves, the rotating platform stops rotating, and when the detection probe is stationary, the rotating platform rotates one revolution; based on the potential distribution matrix and the coefficient matrix of linear conversion between potential and charge, the charge density distribution vector of the surface of the insulating rod is obtained; wherein, the coefficient matrix is ​​obtained by simulation calculation of each cylindrical surface micro-element divided on the surface of the insulating rod using the unit charge method.

[0014] Preferably, the rotating platform includes a rotating support base, a rotating spindle, and a clamping and positioning assembly; the rotating support base is fixed to the grounding platform, and the rotating spindle is rotatably mounted on the rotating support base and connected to the driving mechanism; the clamping and positioning assembly is mounted on the rotating spindle and is used to clamp and fix the insulating pull rod and make the axis of the insulating pull rod coaxial with the axis of the rotating spindle; the driving mechanism is at least one of a servo motor, a stepper motor, a rotary cylinder, or a hydraulic rotary drive device.

[0015] Preferably, the linear displacement platform includes: a guide rail, which is fixedly installed on the grounding platform by a column, and the guiding direction of the guide rail is parallel to the first direction; a slider, which is slidably disposed on the guide rail; and a displacement driving component, which is fixedly installed on the guide rail or the grounding platform, wherein the driving end of the displacement driving component is fixedly connected to the slider and is used to drive the slider to move along the guide rail.

[0016] Preferably, the detection probe is a non-contact active electrostatic potential measurement probe; the tip of the detection probe maintains a preset fixed distance from the surface of the insulating rod; the detection probe is connected to an electrometer via a shielded cable, and the electrometer is used to collect and record the potential data of the surface of the insulating rod in real time.

[0017] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0018] This invention provides a method and system for measuring the surface charge density of an insulating tie rod. By coaxially fixing the insulating tie rod to a grounded rotating platform, a scanning method is employed where the axial stepping of the detection probe is linked to the circumferential rotation of the rotating platform. The platform stops rotating when the probe moves and rotates one revolution when the probe is stationary. Based on the measurement principle of combined circumferential rotation and axial stepping, this method solves the problems of related technologies being unable to meet the requirements of combined axial and circumferential scanning of the cylindrical curved surface of the insulating tie rod, difficulty in maintaining a stable measurement interval, and insufficient automation. This achieves automated and stable acquisition of the full-domain potential of the insulating tie rod surface and construction of the potential distribution matrix. Furthermore, a three-dimensional electrostatic field simulation model is constructed based on the tie rod's geometric dimensions and material properties. The surface is divided into cylindrical curved surface micro-elements, and the potential-charge linear conversion coefficient matrix is ​​calculated using the unit charge method. Based on electrostatic field numerical simulation and the principle of potential-charge linear mapping, the problem of inaccurate inversion of the surface charge density from the acquired potential data is solved, ultimately achieving an accurate solution for the surface charge density distribution of the insulating tie rod. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart of a method for measuring the surface charge density of an insulating tie rod according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of a system for measuring the surface charge density of an insulating tie rod according to an embodiment of the present invention.

[0022] Figure reference numerals:

[0023] 1. Insulating tie rod; 2. Grounding platform; 3. Wire; 4. Detection probe; 5. Clamping and positioning assembly; 6. Rotating platform; 7. Fixture; 8. Linear displacement platform; 9. Slider; 10. Shielded cable; 11. Electrometer. Detailed Implementation

[0024] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0025] To address the issues that related technologies cannot meet the requirements of axial and circumferential composite scanning of the cylindrical curved surface of the insulating tie rod 1, making it difficult to stably maintain the measurement spacing and lacking automation, embodiments of the present invention provide a method and system for measuring the surface charge density of the insulating tie rod 1.

[0026] Among them, such as Figure 1 As shown, an embodiment of the present invention provides a method for measuring the surface charge density of an insulating tie rod 1, which includes the following steps S1 to S4.

[0027] Step S1: Fix the insulating rod 1 to be tested onto the rotating platform 6, so that the axis of the insulating rod 1 coincides with the rotation axis of the rotating platform 6, and ground both ends of the insulating rod 1.

[0028] In step S2, the rotating platform 6 is controlled to rotate at a constant speed by the drive mechanism, while the detection probe 4, which is arranged perpendicular to the axis of the insulating rod 1, collects the potential data on the surface of the insulating rod 1 at a preset sampling frequency.

[0029] Step S3: The linear displacement platform 8 drives the detection probe 4 to move stepwise along the axial direction of the insulating rod 1 until the detection probe 4 traverses the entire axial length of the insulating rod 1, obtains all potential data on the surface of the insulating rod 1, and constructs a potential distribution matrix; wherein, when the detection probe 4 moves, the rotating platform 6 stops rotating, and when the detection probe 4 is stationary, the rotating platform 6 rotates one revolution.

[0030] Step S4: Based on the potential distribution matrix and the coefficient matrix of the linear conversion between potential and charge, the charge density distribution vector on the surface of the insulating rod 1 is obtained; wherein, the coefficient matrix is ​​obtained by simulation calculation of each cylindrical surface micro-element divided on the surface of the insulating rod 1 using the unit charge method.

[0031] Insulating rod 1 is an insulation and power transmission component between the GIS circuit breaker operating mechanism and the arc-extinguishing chamber. It is generally a cylindrical structure with a preset radius. With length It mainly undertakes the functions of power transmission, high-voltage electrical insulation, and equalization of internal electric field, and is a key component to ensure the insulation performance and operational reliability of switchgear.

[0032] The rotating platform 6 is the actuator that realizes coaxial rotational motion. It generally includes a rotating support, a rotating spindle, and a clamping and positioning assembly 5. The clamping and positioning assembly 5 clamps the insulating rod 1 to be tested, so that the insulating rod 1 is coaxially connected with the rotating spindle. The rotating support supports the rotating spindle, so that the insulating rod 1 and the rotating spindle can rotate coaxially. It is the motion carrier for completing circumferential potential acquisition.

[0033] The clamping and positioning assembly 5 includes: calipers, locking bolts, positioning sleeves, elastic chucks, and clamping washers. The rotary support is preferably a bearing housing, with the rotary spindle and bearing housing connected by rolling bearings to achieve high-precision rotary support, radial and axial positioning, and reduced rotational friction loss.

[0034] The insulating rod 1 to be tested is securely fixed on the rotating table of the rotating platform 6 using the clamping and positioning assembly 5. The installation position is precisely adjusted so that the central axis of the insulating rod 1 is completely aligned with the axis of rotation of the rotating main shaft of the rotating platform 6. Two wires 3 are used to connect the two ends of the insulating rod 1 to the grounding platform 2 respectively, ensuring that the two ends of the insulating rod 1 remain at zero potential throughout the measurement process, thus eliminating the interference of the end boundary on the measurement.

[0035] The drive mechanism is a rotary drive device. It can be an electric drive product with a servo motor or stepper motor and a reduction gear, or a pneumatic / hydraulic rotary drive device. The control system outputs a constant speed command to the drive mechanism, which drives the rotary spindle to operate stably at a set angular velocity, thereby driving the insulating tie rod 1 to rotate uniformly around its own axis.

[0036] The detection probe 4 is a non-contact potential detection product, including Kelvin-type active electrostatic probes, vibration-capacitive electrostatic probes, and electrostatic field induction probes, etc., which can collect surface potential data of the insulating tie rod 1 based on principles such as electrostatic induction, capacitive coupling, and vibration modulation. Combined with... Figure 2 As shown, by using the clamp 7 to arrange the detection probe 4 perpendicular to the axis of the insulating rod 1, the distance between the probe and the surface of the rod can be kept constant, and the detection signal can be free of angular deviation, thus avoiding measurement errors at the source and ensuring the accuracy of potential acquisition.

[0037] The clamp 7 can be a three-dimensional adjustable precision clamp, a universal adjustable fixing clamp, or a probe-specific clamping bracket, etc., which has the functions of precise adjustment of height, feed and angle. It can not only realize the quick clamping and stable fixation of the detection probe, but also flexibly fine adjust the probe's posture and relative position to ensure that the probe is always arranged perpendicular to the axis of the insulating pull rod.

[0038] The detection probe 4 is preferably a Kelvin type active electrostatic probe, which has a built-in active amplifier circuit that can improve the signal-to-noise ratio, enhance anti-interference capabilities, and provide better accuracy and stability for cylindrical curved surface detection, without requiring calibration of vibration parameters.

[0039] The detection probe 4 is connected to the electrometer 11 or data acquisition card and signal conditioning module via the shielded cable 10 to realize the functions of high-precision acquisition, stable transmission and real-time recording of surface potential data of the insulating rod 1.

[0040] The preset sampling frequency must be matched with the rotational angular velocity of the rotating platform 6 to ensure that the number of circumferential acquisition points equals the preset sampling frequency divided by the rotational angular velocity. This ensures that a preset number of equiangularly spaced potential data can be acquired in one rotation of the insulating rod 1, and meets the requirements for measurement resolution and acquisition compatibility with the high-precision electrometer 11.

[0041] The linear displacement platform 8 is a single-axis precision linear displacement platform that can work based on the principles of ball screw drive, synchronous belt drive, and linear motor direct drive. Driven by the motor, the detection probe 4 moves precisely along the axis of the insulating tie rod 1, with the stroke covering the entire axial length of the tie rod, and the positioning accuracy matches the measurement resolution requirements.

[0042] The linear displacement platform 8 drives the detection probe 4 to move stepwise along the pull rod axis. When the detection probe 4 moves, the rotating platform 6 stops rotating to avoid the superposition of the two movements, which would cause fluctuations in the measurement interval and offset of the sampling position. When the detection probe 4 is stationary, the rotating platform 6 rotates one revolution, which can complete the full circumferential potential acquisition at a fixed axial position.

[0043] By controlling the rotating platform 6 to rotate at a uniform speed in the circumference through the drive mechanism, the detection probe 4 collects the potential data of the surface of the insulating rod 1 at a preset sampling frequency, and the axial stepping movement of the detection probe 4 realizes the composite scanning of axial stepping and circumferential rotation, stably maintains the measurement interval, and completes the automated and precise acquisition of the potential of the entire cylindrical curved surface of the insulating rod 1.

[0044] The whole-circumferential potential data collected at each axial position is taken as a row of a matrix and arranged sequentially according to the axial step order. All discrete potential data are organized into a two-dimensional array of axial point number multiplied by circumferential point number, and finally a potential distribution matrix characterizing the global potential distribution of the surface of insulating tie rod 1 is formed.

[0045] The coefficient matrix of the linear conversion relationship between potential and charge is obtained by constructing a three-dimensional electrostatic field simulation model based on the geometric dimensions and material properties of the insulating rod 1. After grounding both ends of the insulating rod 1 as the boundary condition, the surface of the insulating rod 1 in the three-dimensional electrostatic field simulation model is meshed to obtain cylindrical surface micro-elements. The cylindrical surface micro-elements are then simulated and calculated using the unit charge method.

[0046] Specifically, the three-dimensional electrostatic field simulation model is built using finite element simulation software based on the geometric dimensions of the insulating rod 1 and the material properties such as the dielectric constant of the insulating material. The model is completely consistent with the geometric structure and working conditions of the actual measurement system, restoring the relative positions of the insulating rod 1, the grounding conductor, and the probe, thus forming a three-dimensional electrostatic field simulation model that matches the measured boundary.

[0047] Based on the constructed three-dimensional electrostatic field simulation model, with the grounding of both ends of the insulating tie rod 1 as the boundary condition, the cylindrical surface of the tie rod is discretized along the axial and circumferential directions according to the measurement resolution in the simulation model to obtain uniform cylindrical surface micro-elements. Using the unit charge method, a unit charge is applied to each individual micro-element in turn, and the remaining micro-elements are set to zero charge. The potential generated by the unit charge in the micro-elements of the entire surface is simulated and calculated. After traversing all micro-elements, a coefficient matrix characterizing the linear conversion relationship between potential and charge is generated.

[0048] Based on the principle of linear superposition of electrostatic fields, a linear equation is established in which the potential distribution matrix is ​​equal to the coefficient matrix multiplied by the charge density distribution vector. By substituting the measured potential distribution matrix and the pre-calculated coefficient matrix into the matrix inversion calculation method, the charge density of each micro-element on the surface of the insulating rod 1 is obtained by inversion, and finally a complete charge density distribution vector is formed.

[0049] The method for measuring the surface charge density of the insulating rod 1 provided in this embodiment of the invention solves the problems of related technologies that cannot meet the requirements of axial and circumferential composite scanning of the cylindrical curved surface of the insulating rod 1, difficulty in maintaining a stable measurement interval, and insufficient automation. It achieves automated and stable acquisition of the surface potential of the insulating rod 1 and construction of the potential distribution matrix. The insulating rod 1 is coaxially fixed to the grounded rotating platform 6. The scanning method adopts the axial stepping of the detection probe 4 and the circumferential rotation of the rotating platform 6 in linkage, the platform stops rotating when the probe moves, and the platform rotates one revolution when the probe is stationary. Based on the measurement principle of composite linkage of circumferential rotation and axial stepping, the method solves the problems of related technologies that cannot meet the requirements of axial and circumferential composite scanning of the cylindrical curved surface of the insulating rod 1, difficulty in maintaining a stable measurement interval, and insufficient automation.

[0050] Then, a three-dimensional electrostatic field simulation model is constructed based on the geometry and material properties of the tie rod. The surface is divided into cylindrical curved surface micro-elements, and the potential and charge linear conversion coefficient matrix is ​​calculated using the unit charge method. Based on the electrostatic field numerical simulation and the principle of potential-charge linear mapping, the problem that the collected potential data cannot be accurately inverted to obtain the surface charge density is solved, and finally the accurate solution of the surface charge density distribution of the insulating tie rod 1 is achieved.

[0051] Further, the method provided in this embodiment of the invention preferably includes the following steps before step S1: fixing the linear displacement platform 8 on the grounding platform 2 by means of a column; wherein the linear displacement platform 8 includes: a slider 9, a guide rail, and a displacement driving component for driving the slider 9 to move along the guide rail; the moving direction of the slider 9 is a first direction; fixing the detection probe 4 on the slider 9 such that the arrangement direction of the detection probe 4 is perpendicular to the first direction, and connecting the output end of the detection probe 4 to the electrometer 11 through a shielded cable 10; fixing the rotating platform 6 on the grounding platform 2, and the rotation axis of the rotating platform 6 is parallel to the first direction.

[0052] Combination Figure 2 As shown, grounding platform 2 is a zero-potential reference conductive platform made of a highly conductive metal, typically in the form of a plate. The conductivity of the highly conductive metal is not less than... Materials such as copper and aluminum alloys are used. The grounding platform 2 provides a stable ground potential reference for the surface charge measurement system of the insulating rod 1, thereby achieving grounding constraints at both ends of the insulating rod 1, stabilizing the measurement boundary conditions, discharging stray static electricity, and ensuring the electrical safety of the system.

[0053] The displacement drive component is the power drive assembly of the linear displacement platform 8, and can adopt various configurations such as ball screw transmission mechanism, synchronous belt transmission mechanism or linear motor direct drive mechanism.

[0054] The power output end of the displacement driving component is fixedly connected to the slider 9. The linear displacement platform 8 is provided with a guide rail extending along the first direction. The slider 9 and the guide rail form a sliding guide fit. The displacement driving component can drive the slider 9 to make high-precision and stable linear reciprocating motion along the guide rail, thereby driving the detection probe 4 fixed on the slider 9 to move in a stepping manner along the axial direction of the insulating rod 1.

[0055] The method provided in this embodiment of the invention can ensure that the relative posture of the detection probe 4 and the insulating rod 1 is constant and the movement direction is accurately matched, and the measurement spacing and detection reference are stably maintained. It provides reliable hardware support for the axial step scanning and circumferential rotation acquisition of the surface potential of the insulating rod 1, and effectively improves the structural stability and potential detection accuracy.

[0056] Further, step S1 in the method provided in the embodiments of the present invention preferably includes: fixing the insulating rod 1 to be tested on the rotating platform 6, so that the insulating rod 1 is between the detection probe 4 and the grounding platform 2, and making the axis of the insulating rod 1 coincide with the rotation axis of the rotating platform 6; adjusting the distance between the tip of the detection probe 4 and the surface of the insulating rod 1, so that the distance reaches a preset fixed distance; connecting the two ends of the insulating rod 1 to the grounding platform 2 through two wires 3.

[0057] The preset fixed distance is determined based on the effective range of the detection probe 4, the measurement accuracy requirements, and the surface curvature of the insulating rod 1. It must meet the conditions of non-contact stable detection and minimal electric field distortion. For example, the preset fixed distance for the commonly used Kelvin type electrostatic probe is 2mm, while it can be set to 3mm in high-precision measurement scenarios.

[0058] The above-mentioned step S1 provided in the embodiment of the present invention, by limiting the installation position of the insulating pull rod 1, precisely adjusting the probe and the pull rod to a preset fixed distance, and grounding the two ends of the pull rod to the ground platform 2 through the double conductor 3, can accurately lock the relative posture of the detection, stably maintain the measurement distance to eliminate distance deviation, and at the same time unify the zero potential reference and suppress the end electric field distortion, thus greatly improving the stability of potential acquisition and measurement accuracy.

[0059] Further, step S3 in the method provided in this embodiment of the invention preferably includes: driving the detection probe 4 to advance one preset step length along the axial direction of the insulating rod 1 after each rotation of the linear displacement platform 8, and stopping the rotation platform 6 when the detection probe 4 moves; until the detection probe 4 traverses the entire axial length of the insulating rod 1 to obtain all potential data on the surface of the insulating rod 1; and arranging all potential data in an orderly manner according to the two-dimensional dimensions of axial and circumferential directions, based on the axial movement position corresponding to each advance of the detection probe 4 and the circumferential sampling position corresponding to one rotation of the insulating rod 1, to construct a potential distribution matrix.

[0060] During testing, the detection probe 4 is moved to the initial axial measurement position near one end of the insulating rod 1 using the linear displacement platform 8. Subsequently, the data acquisition function of the electrometer 11 is simultaneously activated, and the sampling frequency is set. At each axial position, the detection probe 4 remains stationary, and the potential measurement of multiple equally spaced points on the circumferential path is completed by the rotation of the insulating rod 1.

[0061] The number of data points N collected by the rotating platform 6 in one revolution is determined by the rotational angular velocity. With sampling frequency Joint decision, to meet After completing a circumference measurement, the linear displacement platform 8 drives the probe to advance one preset step length along the axial direction. Once the next measurement position is reached, the "rotation-stepping" process described above is repeated.

[0062] Furthermore, the preset step size in the embodiments of the present invention The value range is 2mm to 20mm, with 10mm being preferred.

[0063] This process is repeated until the probe has traversed the entire axial length of the insulating rod 1, thereby obtaining a discrete potential measurement dataset covering the entire cylindrical surface. All acquired potential data are recorded by a high-precision electrometer 11.

[0064] All potential data are arranged in a two-dimensional coordinate order, with the row dimension based on the stepping sequence of the detection probe 4 along the axial direction of the insulating rod 1 and the column dimension based on the circumferential angular sampling sequence collected when the insulating rod 1 rotates one revolution. The measured potential values ​​corresponding to each axial position and circumferential sampling point are then arranged in a two-dimensional coordinate order to form a two-dimensional potential distribution matrix with the number of axial steps as the number of rows and the number of circumferential sampling points as the number of columns.

[0065] The method provided in this embodiment of the invention can achieve accurate potential acquisition across the entire cylindrical surface of the insulating tie rod 1 without blind spots, avoid sampling deviation caused by the superposition of probe movement and tie rod rotation, ensure regular and orderly axial and circumferential sampling positions, and quickly construct a standardized two-dimensional potential distribution matrix, providing stable and reliable data support for subsequent accurate charge density inversion.

[0066] Further, the method provided in this embodiment of the invention, before step S4, preferably includes: constructing a three-dimensional electrostatic field simulation model that matches the actual measurement conditions of the insulating rod 1 based on the geometric dimensions and material properties of the insulating rod 1; uniformly dividing the cylindrical surface of the insulating rod 1 in the three-dimensional electrostatic field simulation model into several cylindrical surface micro-elements according to the two-dimensional dimensions of the axial and circumferential directions, and setting the two ends of the insulating rod 1 as grounding boundary conditions; sequentially applying a preset unit charge to each cylindrical surface micro-element, while keeping the remaining cylindrical surface micro-elements with zero charge, and solving for the potential values ​​generated by the preset unit charge at all cylindrical surface micro-elements based on the principle of linear superposition of electrostatic fields; arranging the potential values ​​corresponding to each cylindrical surface micro-element according to the two-dimensional index of the axial and circumferential directions to obtain the coefficient matrix of linear conversion between potential and charge.

[0067] First, since the potential measured by the detection probe 4 is the result of the combined effect of all charges on the surface of the insulating rod 1, it is necessary to obtain the true surface charge density distribution by solving the inverse electrostatic field problem. Based on the geometric dimensions and material properties of the insulating rod 1, a three-dimensional electrostatic field simulation model matching the actual measurement conditions is constructed. According to the measurement resolution, the cylindrical surface of the insulating rod 1 is divided into M equal parts along the axial direction and N equal parts along the circumference, forming several cylindrical curved surface micro-elements with uniform charge density distribution. The two ends of the insulating rod 1 are set as grounded boundary conditions to ensure that the potential distribution of the simulated electric field is completely consistent with that of the actual measurement system. Among them, the value of M is matched with the preset step size, which is the total axial length of the insulating rod 1 divided by the preset step size.

[0068] Next, based on the unit charge method, the micro-element to which a preset unit charge is applied each time is defined as the excitation micro-element, and the remaining micro-elements without applied charge are defined as the observation micro-element. The preset unit charge is applied to each excitation micro-element individually in turn, while keeping all observation micro-elements in a zero-charge state.

[0069] Based on the principle of linear superposition of electrostatic fields, the potential values ​​generated by the excitation micro-element at all observed micro-element positions are obtained by numerically solving the electrostatic field; the potential values ​​corresponding to all excitation micro-elements are arranged in a regular manner according to the two-dimensional indexes of the axial and circumferential directions, and finally a coefficient matrix representing the linear conversion relationship between potential and charge is constructed.

[0070] The coefficient matrix H is an MN-order square matrix, and its preferred expression is:

[0071] .

[0072] in, for The coefficient matrix of order M and N represents the number of cylindrical surface elements in the axial and circumferential directions, respectively. The potential distribution matrix is ​​obtained by expansion A column vector of potential distributions of order 1; This is a block matrix in the nth row and mth column of the coefficient matrix. ; The block matrix is Square matrix; for The matrix element in row s and column t represents the axis of the t-th column. One, Zhou Xiangdi A preset unit charge is applied at the position of the infinitesimal element of the cylindrical surface, and in the axial direction... One, Zhou Xiangdi The potential value generated at the position of a cylindrical curved surface micro-element; The axial index of the cylindrical surface micro-element is used as the excitation micro-element. Let the circumferential index of the cylindrical surface infinitesimal element be used as the excitation infinitesimal element, and the total excitation index be... , ; The cylindrical surface element is used as the axial index of the observed element. The cylindrical surface infinitesimal element is used as the circumferential index of the observation infinitesimal element, and the total observation index is... , .

[0073] Furthermore, the inverse matrix of the coefficient matrix H The calculation is preferably performed using Tikhonov regularization, and the preferred formula is as follows: ,in, This is the regularization parameter, and its value range is... The present invention is preferably ; It is an identity matrix.

[0074] The method provided in this embodiment of the invention constructs a coefficient matrix based on the principle of linear superposition of electrostatic fields, adapts to the two-dimensional discretized measurement model of the cylindrical surface of the insulating tie rod 1, and maps the axial-circumferential two-dimensional position of the cylindrical surface to a one-dimensional row and column index of the matrix through the index formula, accurately characterizing the linear transfer relationship between potential and charge, and transforming the originally complex three-dimensional electric field inverse problem into a regular linear algebra operation. This ensures the accuracy of the potential-charge mapping, and allows for the rapid inversion of surface charge density through matrix inversion. At the same time, it perfectly matches the actual axial stepping and circumferential rotation sampling logic, effectively improving computational efficiency and data regularity.

[0075] Furthermore, in the method provided in this embodiment of the invention, the formula for calculating the charge density distribution vector on the surface of the insulating rod 1 is as follows:

[0076] .

[0077] in, for The charge density distribution vector of order; The potential distribution matrix is ​​obtained by expansion A column vector of potential distributions of order 1.

[0078] The method provided in this embodiment of the invention, after constructing the coefficient matrix, obtains the inverse matrix by inverting the coefficient matrix H based on the linear transfer relationship between potential and charge. ,Will The measured potential distribution vector on the surface of insulating tie rod 1 Multiply and substitute into the formula The charge density distribution vector on the surface of the insulating rod 1 can be quickly calculated from the measured potential.

[0079] The embodiments of the present invention also provide a measurement system for the surface charge density of an insulating rod 1, which is applied to the measurement method for the surface charge density of the insulating rod 1 in the above embodiments.

[0080] like Figure 2 As shown, the measurement system includes: a grounding platform 2 and a linear displacement platform 8, a rotary platform 6, a drive mechanism, and a control system installed on the grounding platform 2.

[0081] A slider 9 is movably mounted on a linear displacement platform 8, and the slider 9 moves in a first direction. A rotating platform 6 is used to mount the insulating rod 1 to be tested, and the axis of the insulating rod 1 coincides with the rotation axis of the rotating platform 6 and is parallel to the first direction. A detection probe 4 is mounted on the slider 9, and the arrangement direction of the detection probe 4 is perpendicular to the first direction, and it is used to collect the potential data of the surface of the insulating rod 1. A drive mechanism is connected to the rotating platform 6 and is used to drive the rotating platform 6 to rotate along the rotation axis.

[0082] The control system is connected to the linear displacement platform 8 and the drive mechanism. It controls the linear displacement platform 8 to drive the detection probe 4 to move stepwise along the axial direction of the insulating rod 1 until the detection probe 4 traverses the entire axial length of the insulating rod 1, obtains all potential data on the surface of the insulating rod 1, and constructs a potential distribution matrix. When the detection probe 4 moves, the rotating platform 6 stops rotating; when the detection probe 4 is stationary, the rotating platform 6 rotates one revolution. Based on the potential distribution matrix and the coefficient matrix of the linear conversion between potential and charge, the charge density distribution vector on the surface of the insulating rod 1 is obtained. The coefficient matrix is ​​obtained by simulation calculation of each cylindrical surface micro-element on the surface of the insulating rod 1 using the unit charge method.

[0083] The assembly structure and motion coordination of the linear displacement platform 8, rotary platform 6, detection probe 4, and drive mechanism in the above system, as well as the potential data acquisition rules, potential distribution matrix construction method, coefficient matrix simulation construction process, and charge density inversion calculation logic, all refer to the description of the measurement method in the above embodiments. The control system is used to execute the control flow of steps S2 to S4 in the above measurement method, which will not be repeated here.

[0084] The system provided in this embodiment of the invention employs a coordinated motion structure in which a rotating platform 6 drives the insulating rod 1 to rotate and a linear displacement platform 8 drives the detection probe 4 to step axially. The detection probe 4 is oriented perpendicular to the axis of the insulating rod 1. The driving mechanism and the linear displacement platform 8 work in sequence to achieve precise control of the probe's stationary sampling and movement. Furthermore, based on three-dimensional electrostatic field simulation and the unit charge method, a precise coefficient matrix is ​​constructed to complete charge inversion. This system achieves the technical effects of full-area potential acquisition without blind zones on the cylindrical surface of the insulating rod 1, simplified motion control mechanism, high measurement accuracy and data stability, and rapid and accurate charge density inversion. It can also be adapted to the specific measurement requirements of cylindrical insulating rods 1, significantly improving the automation and standardization level of the measurement process.

[0085] Furthermore, the rotating platform 6 of the system provided in this embodiment of the invention includes: a rotating support base, a rotating spindle, and a clamping and positioning assembly 5; the rotating support base is fixed on the grounding platform 2, and the rotating spindle is rotatably disposed on the rotating support base and transmittedly connected to the drive mechanism; the clamping and positioning assembly 5 is disposed on the rotating spindle and is used to clamp and fix the insulating pull rod 1 and arrange the axis of the insulating pull rod 1 coaxially with the axis of the rotating spindle; the drive mechanism is at least one of a servo motor, a stepper motor, a rotary cylinder, or a hydraulic rotary drive device.

[0086] The clamping and positioning component 5 is preferably a caliper, which can quickly and securely clamp the insulating pull rod 1, ensure that the axis of the pull rod is strictly coaxial with the axis of rotation of the rotating platform 6, facilitate easy assembly and adjustment, and achieve high positioning accuracy, effectively preventing eccentricity or wobbling during rotation.

[0087] The drive mechanism is preferably a stepper motor, which can achieve precise adjustment of rotation speed, rapid start and stop response, and precise synchronization of rotation angle and circumferential sampling, thus meeting the control requirements of uniform rotation and uniform sampling at equal angles of the insulating rod 1.

[0088] Furthermore, the linear displacement platform 8 includes: a guide rail, which is fixedly installed on the grounding platform 2 by a column, and the guiding direction of the guide rail is parallel to the first direction; a slider 9, which is slidably disposed on the guide rail; and a displacement driving component, which is fixedly installed on the guide rail or the grounding platform 2, and the driving end of the displacement driving component is fixedly connected to the slider 9 for driving the slider 9 to move along the guide rail.

[0089] The displacement drive component is preferably a ball screw drive assembly, which can achieve smooth and stable axial displacement drive, high step positioning accuracy, precise and reliable step length control, and no axial movement or backlash. This ensures that the detection probe 4 moves at a uniform and precise speed along the axial direction of the insulating rod 1, effectively guaranteeing the axial position accuracy of the potential sampling.

[0090] Furthermore, the detection probe 4 is a non-contact active electrostatic potential measurement probe; the tip of the detection probe 4 maintains a preset fixed distance from the surface of the insulating rod 1; the detection probe 4 is connected to the electrometer 11 through the shielded cable 10, and the electrometer 11 is used to collect and record the potential data of the surface of the insulating rod 1 in real time.

[0091] The detection probe 4 is preferably a Kelvin type active electrostatic probe, which has a built-in active amplifier circuit that can improve the signal-to-noise ratio, enhance anti-interference capabilities, and provide better accuracy and stability for cylindrical curved surface detection, without requiring calibration of vibration parameters.

[0092] Embodiments of the present invention also provide a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a computer's processor, is used to cause the computer to perform a method according to an embodiment of the present invention.

[0093] Embodiments of the present invention also provide a computer program product, including a computer program, wherein the computer program, when executed by a computer's processor, is used to cause the computer to perform the method of an embodiment of the present invention.

[0094] Computer programs for implementing the methods of embodiments of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0095] In the context of embodiments of the present invention, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable signal medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, or infrared systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory, read-only memory, erasable programmable read-only memory, optical fibers, portable compact disk read-only memory, optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0096] It should be noted that the term "comprising" and its variations used in the embodiments of the present invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "a plurality" mentioned in the embodiments of the present invention are illustrative and not restrictive, and those skilled in the art should understand that unless explicitly indicated otherwise in the context, they should be understood as "one or more".

[0097] The steps described in the method embodiments provided by the present invention can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0098] The term "embodiment" in this specification refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply independence or alternativeity from other embodiments. The various embodiments in this specification are described in a related manner, with reference to each other for similar or identical parts. In particular, for apparatus, device, and system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, and relevant details are referred to in the description of the method embodiments.

[0099] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for measuring the surface charge density of an insulating tie rod, characterized in that, The method includes: The insulating rod to be tested is fixed on the rotating platform, such that the axis of the insulating rod coincides with the rotation axis of the rotating platform, and both ends of the insulating rod are grounded. The rotating platform is controlled to rotate at a constant speed by a drive mechanism, while a detection probe arranged perpendicular to the axis of the insulating rod collects potential data on the surface of the insulating rod at a preset sampling frequency. The detection probe is driven by a linear displacement platform to move stepwise along the axial direction of the insulating rod until the detection probe traverses the entire axial length of the insulating rod, thereby obtaining all potential data on the surface of the insulating rod and constructing a potential distribution matrix; wherein, the rotating platform stops rotating when the detection probe moves, and the rotating platform rotates one revolution when the detection probe is stationary; Based on the potential distribution matrix and the coefficient matrix of the linear conversion between potential and charge, the charge density distribution vector of the insulating rod surface is obtained by solving the problem; wherein, the coefficient matrix is ​​obtained by simulation calculation of each cylindrical surface micro-element of the insulating rod surface using the unit charge method.

2. The method for measuring the surface charge density of an insulating tie rod according to claim 1, characterized in that, Before fixing the insulating tie rod to be tested to the rotating platform, the method includes: A linear displacement platform is fixedly mounted on a grounded platform using a column; wherein, the linear displacement platform includes: a slider, a guide rail, and a displacement driving component for driving the slider to move along the guide rail; the direction of movement of the slider is a first direction; The detection probe is fixedly mounted on the slider, such that the arrangement direction of the detection probe is perpendicular to the first direction, and the output end of the detection probe is connected to the electrometer through a shielded cable. The rotating platform is fixedly mounted on the grounding platform, and the rotation axis of the rotating platform is parallel to the first direction.

3. The method for measuring the surface charge density of an insulating tie rod according to claim 2, characterized in that, The insulating rod to be tested is fixed on a rotating platform such that the axis of the insulating rod coincides with the rotation axis of the rotating platform, and both ends of the insulating rod are grounded, including: The insulating rod to be tested is fixed on the rotating platform, such that the insulating rod is positioned between the detection probe and the grounding platform, and the axis of the insulating rod coincides with the rotation axis of the rotating platform. Adjust the distance between the tip of the detection probe and the surface of the insulating rod, so that the distance reaches a preset fixed distance; The two ends of the insulating rod are connected to the grounding platform via two wires.

4. The method for measuring the surface charge density of an insulating tie rod according to claim 1, characterized in that, The detection probe is driven by a linear displacement platform to move stepwise along the axial direction of the insulating rod until it traverses the entire axial length of the insulating rod, obtaining all potential data on the surface of the insulating rod and constructing a potential distribution matrix, including: After the insulating rod rotates once, the linear displacement platform drives the detection probe to advance one preset step length along the axis of the insulating rod, and the rotating platform stops rotating when the detection probe moves. The detection probe continues to traverse the entire axial length of the insulating rod to obtain all potential data on the surface of the insulating rod. All the potential data are arranged in an orderly manner according to the two-dimensional dimensions of axial and circumferential, based on the axial movement position corresponding to each forward movement of the detection probe and the circumferential sampling position corresponding to one rotation of the insulating rod, to construct a potential distribution matrix.

5. The method for measuring the surface charge density of an insulating tie rod according to claim 1, characterized in that, Before solving for the charge density distribution vector on the surface of the insulating tie rod, the method includes: Based on the geometric dimensions and material properties of the insulating rod, a three-dimensional electrostatic field simulation model matching the actual measurement conditions of the insulating rod is constructed. The cylindrical surface of the insulating rod in the three-dimensional electrostatic field simulation model is divided into a uniform mesh according to the two-dimensional dimensions of the axial and circumferential directions to obtain several cylindrical curved surface micro elements, and the two ends of the insulating rod are set as ground boundary conditions. A preset unit charge is applied sequentially to each of the cylindrical surface micro-elements, while the remaining cylindrical surface micro-elements remain at zero charge. Based on the principle of linear superposition of electrostatic fields, the potential values ​​generated by the preset unit charge at all the cylindrical surface micro-elements are solved. The potential values ​​corresponding to each of the cylindrical surface micro-elements are arranged according to the two-dimensional indexes in the axial and circumferential directions to obtain the coefficient matrix of linear conversion between potential and charge.

6. The method for measuring the surface charge density of an insulating tie rod according to claim 5, characterized in that, The formula for calculating the charge density distribution vector on the surface of the insulating tie rod is: ； ； in, for The charge density distribution vector of order; for The coefficient matrix of order M and N represents the number of cylindrical surface elements in the axial and circumferential directions, respectively. The potential distribution matrix is ​​obtained by expansion A column vector of potential distributions of order 1; This is a block matrix in the nth row and mth column of the coefficient matrix. ; The block matrix is Square matrix; for The matrix element in row s and column t represents the axis of the t-th column. One, Zhou Xiangdi A preset unit charge is applied at the position of the infinitesimal element of the cylindrical surface, and in the axial direction... One, Zhou Xiangdi The potential value generated at the position of a cylindrical curved surface micro-element; The axial index of the cylindrical surface micro-element is used as the excitation micro-element. Let the circumferential index of the cylindrical surface infinitesimal element be used as the excitation infinitesimal element, and the total excitation index be... , ; The cylindrical surface element is used as the axial index of the observed element. The cylindrical surface infinitesimal element is used as the circumferential index of the observation infinitesimal element, and the total observation index is... , .

7. A system for measuring the surface charge density of an insulating tie rod, applied to the method for measuring the surface charge density of an insulating tie rod according to any one of claims 1 to 6, characterized in that, The system includes: a grounding platform and a linear displacement platform, a rotary platform, a drive mechanism, and a control system installed on the grounding platform; A slider is movably mounted on the linear displacement platform, and the slider moves in a first direction. A rotating platform is used to mount the insulating rod to be tested, such that the axis of the insulating rod coincides with the rotation axis of the rotating platform and is parallel to the first direction. A detection probe is mounted on the slider, and the probe is arranged perpendicular to the first direction, for collecting potential data from the surface of the insulating rod. A driving mechanism is connected to the rotating platform and drives the rotating platform to rotate along the rotation axis. The control system is connected to the linear displacement platform and the drive mechanism, and is used to control the linear displacement platform to drive the detection probe to move stepwise along the axial direction of the insulating rod until the detection probe traverses the entire axial length of the insulating rod, obtains all potential data of the surface of the insulating rod, and constructs a potential distribution matrix; wherein, when the detection probe moves, the rotating platform stops rotating, and when the detection probe is stationary, the rotating platform rotates one revolution; based on the potential distribution matrix and the coefficient matrix of linear conversion between potential and charge, the charge density distribution vector of the surface of the insulating rod is obtained; wherein, the coefficient matrix is ​​obtained by simulation calculation of each cylindrical surface micro-element of the surface of the insulating rod using the unit charge method.

8. The system for measuring the surface charge density of an insulating tie rod according to claim 7, characterized in that: The rotating platform includes a rotating support base, a rotating spindle, and a clamping and positioning assembly; The rotating support base is fixed to the grounding platform, and the rotating spindle is rotatably mounted on the rotating support base and connected to the driving mechanism. The clamping and positioning assembly is mounted on the rotating spindle and is used to clamp and fix the insulating rod and make the axis of the insulating rod coaxial with the axis of the rotating spindle. The drive mechanism is at least one of a servo motor, a stepper motor, a rotary cylinder, or a hydraulic rotary drive device.

9. The system for measuring the surface charge density of an insulating tie rod according to claim 7, characterized in that: The linear displacement platform includes: The guide rail is fixedly installed on the grounding platform by a column, and the guiding direction of the guide rail is parallel to the first direction; A slider is slidably mounted on the guide rail; A displacement driving component is fixedly installed on the guide rail or the grounding platform. The driving end of the displacement driving component is fixedly connected to the slider and is used to drive the slider to move along the guide rail.

10. The system for measuring the surface charge density of an insulating tie rod according to claim 7, characterized in that: The detection probe is a non-contact active electrostatic potential measurement probe; the tip of the detection probe maintains a preset fixed distance from the surface of the insulating rod; The detection probe is connected to an electrometer via a shielded cable. The electrometer is used to collect and record the potential data on the surface of the insulating rod in real time.

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