Electric insulation part surface charge measuring method based on nano-library level charge detector

Abstract

The invention discloses an electric insulation part surface charge measurement method based on a nano-library level charge detector, and solves the problems that the nano-library level charge detector is high in test sensitivity, and a metal part of an automatic measurement device carrying the nano-library level charge detector is close to a test probe or a ground surface zero potential position; according to the invention, a non-metal device is used to convey a nano-storage level charge detector to a detection position of a detected object in a long distance, and the non-metal device is controlled to act to drive the nano-storage level charge detector to act in sequence to carry out coverage type omnibearing detection on the detected object. Relatively accurate charge parameters are obtained; the method can be widely applied to the field of surface charge detection of insulating devices.

Description

Technical Field

[0001] The invention relates to a method for measuring the surface charge of an electric insulating component based on a nanocubic-meter-level charge detector, and belongs to the technical field of surface charge detection of insulating devices. Background Art

[0002] With the vigorous development of modern power systems, enclosed high-voltage equipment, such as GIS (gas-insulated metal-enclosed switchgear) and GIL (gas-insulated transmission line), has been increasing in the system. With this comes an urgent need for equipment operation reliability. Insulation components isolate high-voltage components from the external environment to ensure the normal operation of the power system. However, during the operation of power equipment, charge accumulation will occur on the surface of the insulation components, causing uneven electric field distribution and surface adsorption of dirt. In the above case, excessive local electric field strength of the insulation components will cause partial discharge, resulting in equipment damage or even short circuit, seriously affecting the reliability and operation stability of the equipment. In this context, the impact of charge attachment on the safe operation of GIS and GIL equipment has become increasingly prominent, far exceeding the impact of charge on other power equipment. However, the current charge detection device and method inevitably introduce components that affect charge distribution, resulting in reduced detection accuracy, which seriously threatens the reliability of GIS and GIL equipment operation. Therefore, in view of the problem of charge accumulation on the surface of the insulation components of power equipment, a high-precision insulation material surface charge accumulation measurement method and device are developed to monitor and analyze the surface charge of the insulator with high precision, which helps to prevent potential failures in advance and is crucial to ensure the safe operation of power equipment.

[0003] At present, the detection of surface charge of insulating parts mainly adopts electrostatic field measurement method, charge measurement instrument method, ground discharge method and thermal infrared imaging method, and their respective advantages and disadvantages are as follows: (1) The electrostatic field measurement method is to infer the surface charge distribution by non-contact measuring the electric field strength near the surface of the insulator. However, this method is limited by the electric field test sensor and can only locate the measurement point to the average electric field value of a 10 cm square space. Therefore, it is impossible to measure the electric field and charge at a specific point.

[0004] (2) The charge measurement instrument method directly measures the charge on the surface of an insulator. The measurement results are highly accurate and have a wide range of applications. However, the device itself contains conductive materials, which can cause distortion of the surrounding electric field, thus affecting the measurement results.

[0005] (3) The ground discharge method indirectly measures the charge by grounding the object to be measured and detecting the discharge process of the charge released from its surface. However, since the charge of the object to be measured will change after being grounded, the measurement result will be inaccurate.

[0006] (4) Thermal infrared imaging indirectly infers the charge on the surface of an object by measuring the thermal radiation distribution on the surface of the object in a non-contact, rapid, and real-time manner. However, the data obtained by this method is the heat distribution of the entire area, rather than directly reflecting the charge amount or charge distribution at a specific point.

[0007] Therefore, in order for the measuring device to detect the charge at a specific point, the influence of the material and shape of the testing device on the space charge should be minimized as much as possible to avoid the measured object interfering with the measurement result. Summary of the invention

[0008] The present invention overcomes the shortcomings of the prior art and provides a method for measuring the surface charge of an electrical insulating component based on a nanocolumn-level charge detector, thereby solving the problem that the nanocolumn-level charge detector has high test sensitivity and the metal parts of an automated measuring device equipped with the nanocolumn-level charge detector are close to a zero potential position such as a test probe or the ground, thereby causing the spatial charge distribution to change beyond an expected value.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: a surface charge measurement method of an electric insulating component based on a nanoscale charge detector, comprising a nanoscale charge detector, using boundary conditions The potential of each node is calculated using the following formula : ; According to the potential of each node The electric field strength is obtained as follows: ; in, is the electric field strength (V / m); is the Hamiltonian operator; represents the total number of body units; The contribution of each unit to the potential investigation quantity; is the potential at any point in the system; is the potential of the reference point on the boundary; In the above boundary conditions, if there is a metal conductor in the system, it is an equipotential body with the same potential and the internal electric field is 0; if the above metal conductor is grounded, since the earth is at zero potential, the potential at each point of the metal conductor and the internal electric field are all 0, resulting in multiple components in the above formula. is 0, resulting in the potential of the final measured point and charge q Unnecessary changes occur; Based on this, by utilizing multi-degree-of-freedom non-metallic equipment, the nanoscale charge detector is sent to the detection surface for automatic measurement, and accurate charge parameters that are not affected by external interference are obtained.

[0010] Furthermore, the structure of the non-metallic equipment includes a first motor, a second motor, a third motor, a turntable, a spring, an induction switch, a rocker arm, a bracket, a base and a control module, the body of the first motor is transversely fixed on the base, a first lead screw is transversely arranged on the power output end of the first motor, a first slider is matched and mounted on the first lead screw, one side of the bracket is fixedly arranged on the first slider, the other side of the bracket is movably arranged on the base, a second motor is arranged on the top of the bracket, a turntable is movably arranged in the middle of the bracket, the power output end of the second motor is connected to the turntable power through a gear assembly, the body of the third motor is fixedly arranged on the end surface of the turntable, a second lead screw is vertically arranged on the power output end of the third motor, a second slider is matched and arranged on the lead screw, a rocker arm is transversely fixedly arranged on the second slider, an induction switch is arranged on the rocker arm, the nanoscale charge detector is vertically arranged on the rocker arm through a spring, and the control module is used to coordinate the actions of the first motor, the second motor, the third motor and the induction switch.

[0011] Furthermore, during detection, the rotation center axis of the turntable and the rotation center axis of the object to be detected are in a straight line.

[0012] Furthermore, except for the first motor, the second motor and the third motor, the remaining components of the non-metallic equipment are made of non-metallic insulating materials.

[0013] Furthermore, the total transverse length of the rocker arm is not less than 60 cm.

[0014] Furthermore, during the detection process, the first motor, the second motor and the third motor are controlled to act in coordination so that after the nanometer-level charge detector reaches the detection position, the detection head of the nanometer-level charge detector is pressed against the object to be detected by a spring, and then circles the object to be detected, while detecting several detection points at intervals, and then the nanometer-level charge detector is driven to move axially along the object to be detected, and the above detection action is repeated until the detection is completed and the nanometer-level charge detector is reset.

[0015] Furthermore, during the detection process, the first motor, the second motor and the third motor are controlled to act in coordination so that the detection head of the nanoscale charge detector is pressed against the object to be detected to collect the charge signal. When the spring is compressed to a certain extent, the switch is triggered, the third motor reverses, and the detection head of the nanoscale charge detector moves away from the object to be detected. At the end of a detection cycle, the second motor or the first motor is driven to move the detection head of the nanoscale charge detector to the next detection point, and the above actions are repeated until the detection is completed.

[0016] Furthermore, the nanometer-level charge detector and spring assembly are movably arranged in the arc groove at the end of the rocker arm. By adjusting the position of the nanometer-level charge detector and the spring assembly in the arc groove, it is ensured that the probe of the nanometer-level charge detector can remain vertical to the detection position of the object to be measured.

[0017] Compared with the prior art, the present invention has the following beneficial effects: the present invention uses non-metallic equipment to transport the nanometer-level charge detector to the detection position of the detected object over a long distance, controls the movement of the non-metallic equipment to drive the nanometer-level charge detector to move in turn to perform a comprehensive and comprehensive detection of the detected object, and obtains more accurate charge parameters for decision-making. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure when the non-metallic device in the present invention is manually driven.

[0021] Figure 3 It is a schematic diagram of the average value of the charge released per unit time at the test point when there is a conductor or not at different voltage levels in the present invention.

[0022] In the figure: 1 is the first motor, 2 is the second motor, 3 is the third motor, 4 is the turntable, 5 is the nanometer-level charge detector, 6 is the spring, 7 is the induction switch, 8 is the rocker arm, 9 is the bracket, 10 is the base, 11 is the first lead screw, 12 is the first slider, 13 is the gear assembly, 14 is the second lead screw, 15 is the second slider, and 16 is the arc groove. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with specific embodiments.

[0024] like Figure 1 , Figure 3 As shown, the surface charge measurement method of the electric insulation component based on the nanoscale charge detector of the present invention comprises a nanoscale charge detector 5, using the boundary condition The potential of each node is calculated using the following formula : ; According to the potential of each node The electric field strength is obtained as follows: ; in, is the electric field strength (V / m); is the Hamiltonian operator; represents the total number of body units; The contribution of each unit to the potential investigation quantity; is the potential at any point in the system; is the potential of the reference point on the boundary; In the above boundary conditions, if there is a metal conductor in the system, it is an equipotential body with the same potential and the internal electric field is 0; if the above metal conductor is grounded, since the earth is at zero potential, the potential at each point of the metal conductor and the internal electric field are all 0, resulting in multiple components in the above formula. is 0, resulting in the potential of the final measured point and charge q Unnecessary changes occur; Based on this, by using a multi-degree-of-freedom non-metallic device to send the nanoscale charge detector 5 to the detection surface for automatic measurement, accurate charge parameters are obtained without external interference; The structure of the non-metallic equipment includes a first motor 1, a second motor 2, a third motor 3, a turntable 4, a spring 6, an induction switch 7, a rocker arm 8, a bracket 9, a base 10 and a control module. The body of the first motor 1 is transversely fixed on the base 10, a first lead screw 11 is transversely arranged on the power output end of the first motor 1, and a first slider 12 is matched on the first lead screw 11. One side of the bracket 9 is fixedly arranged on the first slider 12, and the other side of the bracket 9 is movably arranged on the base 10. The second motor 2 is arranged on the top of the bracket 9, and the turntable 4 is movably arranged in the middle of the bracket 9. The power output end of the second motor 2 is connected to the turntable 4 through a gear assembly 13. The body of the third motor 3 is fixedly arranged on the end face of the turntable 4, a second lead screw 14 is vertically arranged on the power output end of the third motor 3, a second slider 15 is matched on the lead screw 14, a rocker arm 8 is horizontally fixedly arranged on the second slider 15, the total horizontal length of the rocker arm 8 is not less than 60 cm, an induction switch 7 is arranged on the rocker arm 8, the nanometer-level charge detector 5 is vertically arranged on the rocker arm 8 through a spring 6, the control module is used to coordinate the actions of the first motor 1, the second motor 2, the third motor 3 and the induction switch 7, and except the first motor 1, the second motor 2 and the third motor 3, the remaining components of the non-metallic equipment are made of non-metallic insulating materials.

[0025] During detection, the rotation center axis of the turntable 4 is in a straight line with the rotation center axis of the object to be measured. During the detection process, the first motor 1, the second motor 2 and the third motor 3 are controlled to work together so that the detection head of the nanometer-level charge detector 5 is pressed on the object to be measured to collect the charge signal. When the spring 6 is compressed to a certain extent, the switch is triggered, the third motor 3 reverses, and the detection head of the nanometer-level charge detector 5 moves away from the object to be measured. At the end of a detection cycle, the second motor 2 or the first motor 1 is driven to move the detection head of the nanometer-level charge detector 5 to the next detection point, and the above actions are repeated until the detection is completed.

[0026] Each time a position is detected, the induction switch 7 sends a signal to the control module. The control module receives the signal from the induction switch 7 and controls the corresponding first motor 1, second motor 2, and third motor 3 to act alone or synchronously.

[0027] The present invention movably sets the nanometer-level charge detector 5 and spring 6 assembly in the arc groove 16 at the end of the rocker arm 8, and by adjusting the position of the nanometer-level charge detector 5 and spring 6 assembly in the arc groove 16, it is ensured that the probe of the nanometer-level charge detector 5 can remain vertical to the detection position of the object to be measured.

[0028] Whether the present invention is detecting the charge amount at a certain point on the surface of an object or detecting the charge amount at a certain point in space, the detected point does not exist independently, but is in a huge system consisting of a non-negligible volume of the object to be detected, a charge detection device, and a storage table. Therefore, the electric field and charge of the measured point need to be comprehensively considered by the influence of each element in the system, and the charge amount is solved under a three-dimensional electrostatic field. In an electrostatic field, the electric field at each point satisfies Ampere's loop and Gauss's law: (1); (2); in, is the electric field strength (V / m), is the electric flux density (C / m 2 ), is the charge density (C / m 3 ), is the Hamiltonian operator.

[0029] Also because and ,in, is the relative dielectric constant of the dielectric, is the potential, so formula (3) is derived as: (3); In a homogeneous medium, , is the Laplace operator, so: (4); (5); From this we can see that the charge at a point is closely related to the potential at which it is located. If the potential changes, the volume charge and surface charge will also change.

[0030] When calculating the potential and charge of the measured point in a multi-element system, the finite element method based on the variational method can be used. The unknown field function to be solved in the solution domain is represented piecewise by the assumed approximate function in each unit. The approximate functions in these units are usually expressed by the values ​​of the unknown field function and its derivatives at each node of the unit and the corresponding interpolation functions.

[0031] use Finite parameters To approximate the properties of the entire system; the contributions of all sub-regions are superimposed and combined to obtain The equation is: (6); The entire system is divided into many identifiable entities by sub-regions ,then (7); In the formula, is the contribution of each unit to the quantity under consideration.

[0032] For electrostatic fields, the volume V The corresponding variational problem is: (8); in, is the potential of the reference point on the boundary.

[0033] After discretization using the above method, the original universal function can be replaced by superimposing the universal function of each unit: (9); In the formula represents the total number of volume units, As shown in formula (10): (10); In the formula, is the contribution of each unit to the potential study quantity.

[0034] Let formula (9) be To find the differential, write it in matrix form: (11); Where: (12); in, , For a certain point ( x , y , z )’s interpolation function; (13); In the formula , , , , , , , is the volume of a tetrahedron The algebraic cofactor of (14); Formula (9) After differentiation, all units are combined to obtain the system of equations: (15); Therefore, due to the boundary condition potential of the computational domain It is known that the value of any point in the entire system can be gradually obtained by combining formulas (7)-(15).

[0035] Electric field strength E The calculation of follows the above formula, then (16); Therefore, combining equations (9) and (16), and combining , represents the electric field strength of each node, as shown in formula (17).

[0036] (17); Formula (17) can be calculated by first using formula (15) and boundary conditions φ 0 Obtain the potential of each node Just substitute it in.

[0037] At this time, in the boundary conditions, if there is a metal conductor in the system, it is an equipotential body with the same potential and the internal electric field is 0; if the above metal conductor is grounded, since the earth is at zero potential, the potential at each point of the metal conductor and the internal electric field are all 0, then there will be multiple components in formula (17) E is 0, resulting in the potential of the final measured point φ and charge q Unnecessary changes occur.

[0038] Therefore, in order to reduce the influence of metal conductors on the electric field in space, the arm distance of this device reaches more than 60cm, and all materials except the motor are non-metallic insulating materials.

[0039] The optimized surface charge detection device for power insulating components based on the nanometer level meter minimizes the influence of metal components on space charge and surface charge of insulating materials.

[0040] Embodiment 1

[0041] For umbrella-shaped and cylindrical insulating components with a detection angle less than 100°, the first embodiment is performed according to the following specific operation steps: Step 1: When the center of the test bench, that is, the center of the turntable 4, is consistent with the center of the insulating component, the first motor 1 is started to control the rocker arm 8 to move horizontally so that the nanometer-level charge detector 5 reaches and aligns with the measured point; Step 2: At this time, the third motor 3 is started to control the rocker arm 8 to move vertically, and the rocker arm 8 is pushed to drive the nanometer-level charge detector 5 to contact the insulating component and squeeze the rear spring 6 of the nanometer-level charge detector 5. The data collected by the nanometer-level charge detector 5 is transmitted to the industrial computer; when the induction switch 7 is started, the third motor 3 is started to reverse and retreat, and the first data collection is completed; Step 3: Start the second motor 2 to drive the turntable 4 to rotate to the second measuring point, and repeat the second step; Step 4: After one torus is detected, start the first motor 1 to move forward according to the set forward distance threshold to reach the second detection torus, and repeat the above steps, but this time the second motor 2 must reverse to avoid line entanglement.

[0042] Embodiment 2

[0043] For umbrella-shaped and cylindrical insulating components with a detection angle greater than or equal to 100°, the second embodiment is performed according to the following specific operation steps: Step 1: When the center of the test bench, that is, the turntable 4, is consistent with the center of the insulating component, the third motor 3 is started first to make the nanometer-level charge detector 5 reach the point to be measured. At this time, the rotation angle of the nanometer-level charge detector 5 is perpendicular to the measured surface; Step 2: Start the first motor 1, control the rocker arm 8 to move horizontally, push the rocker arm 8 to drive the nanometer-level charge detector 5 to contact the insulating component and squeeze the rear spring 6 of the nanometer-level charge detector 5, and the data collected by the nanometer-level charge detector 5 is transmitted to the industrial computer; when the induction switch 7 is started, start the first motor 1 to reverse and retreat, and the first data collection is completed; Step 3: Start the second motor 2 to drive the turntable 4 to rotate to the second measuring point, and repeat step 2; Step 4: After one ring surface detection is completed, start the third motor 3 to move forward according to the set forward distance threshold to reach the second detection ring surface, and repeat the above steps, but this time the second motor 2 must reverse to avoid line entanglement.

[0044] Embodiment 3

[0045] like Figure 2 As shown, in this embodiment, the non-metallic device is a manual drive structure, that is, the first motor 1, the second motor 2, and the third motor 3 are replaced with a manual drive structure, and all non-metallic insulating components are used, which can further reduce the potential impact of the motor.

[0046] Embodiment 4

[0047] Taking the space charge measurement results under 24-26kV (0.5 kV step) DC electric field as an example, when there are conductors around the electric field measurement area (for example: grounded operators standing around the instrument) and when there are no conductors during the discharge process, the average value of the charge released at the test point per unit time is obtained. The test results are compared. Figure 2 shown.

[0048] from Figure 2 It can be seen that the average value of the charge released per unit time when there is a conductor is greater than the average value of the charge released when there is no conductor, and as the voltage value increases, the ratio of the charge released per unit time with a conductor to that without a conductor will decrease. Therefore, from the experimental results, it can be concluded that when the conductor is close to the electric field, part of the charge will be lost or shielded through the conductive path of the conductor, thereby reducing the value of the charge released per unit time in the electric field area. And as the voltage increases, the number of charges in the electric field increases rapidly, which leads to the weakening of the shielding effect of the conductor on the electric field under high voltage conditions, resulting in a decrease in the ratio of the charge released per unit time when there is a conductor and when there is no conductor.

[0049] In summary, according to the experimental results, it can be concluded that when conductive materials such as the human body and metal interfere around the measuring probe, the average value of the charge released per unit time will decrease, causing the spatial charge distribution to change beyond the normal value. Therefore, it is necessary to minimize the influence of the material and shape of the test device on the spatial charge and improve the accuracy of the measurement value of the nanoscale charge detection device.

[0050] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for measuring the surface charge of an electrical insulating component based on a nanocolumn-level charge detector, comprising a nanocolumn-level charge detector (5), characterized in that: Using boundary conditions The potential of each node is calculated using the following formula : ； According to the potential of each node The electric field strength is obtained as follows: ； in, is the electric field strength (V / m); is the Hamiltonian operator; represents the total number of body units; The contribution of each unit to the potential investigation quantity; is the potential at any point in the system; is the potential of the reference point on the boundary; In the above boundary conditions, if there is a metal conductor in the system, it is an equipotential body with the same potential and the internal electric field is 0; if the above metal conductor is grounded, since the earth is at zero potential, the potential at each point of the metal conductor and the internal electric field are all 0, resulting in multiple components in the above formula. is 0, resulting in the potential of the final measured point and charge q Unnecessary changes occur; Based on this, by utilizing a multi-degree-of-freedom non-metallic device, a nanometer-level charge detector (5) is sent to the detection surface for automatic measurement, thereby obtaining accurate charge parameters that are not subject to external interference.

2. The method for measuring the surface charge of an electric insulating component based on a nanoscale charge detector according to claim 1 is characterized in that: The structure of the non-metallic device comprises a first motor (1), a second motor (2), a third motor (3), a turntable (4), a spring (6), an induction switch (7), a rocker arm (8), a bracket (9), a base (10) and a control module, wherein the body of the first motor (1) is transversely fixed on the base (10), a first lead screw (11) is transversely arranged on the power output end of the first motor (1), a first slider (12) is matched and mounted on the first lead screw (11), one side of the bracket (9) is fixedly arranged on the first slider (12), the other side of the bracket (9) is movably arranged on the base (10), the top of the bracket (9) is provided with the second motor (2), and the middle part of the bracket (9) is movably provided with a A turntable (4) is provided, the power output end of the second motor (2) is connected to the turntable (4) through a gear assembly (13), the body of the third motor (3) is fixedly arranged on the end surface of the turntable (4), a second lead screw (14) is vertically arranged on the power output end of the third motor (3), a second slider (15) is matched with the lead screw (14), a rocker arm (8) is horizontally fixedly arranged on the second slider (15), an induction switch (7) is arranged on the rocker arm (8), the nanometer-level charge detector (5) is vertically arranged on the rocker arm (8) through a spring (6), and the control module is used to coordinate the actions of the first motor (1), the second motor (2), the third motor (3) and the induction switch (7).

3. The method for measuring the surface charge of an electric insulating component based on a nanoscale charge detector according to claim 2 is characterized in that: During detection, the rotation center axis of the turntable (4) and the rotation center axis of the object to be detected are in a straight line.

4. The method for measuring the surface charge of an electric insulating component based on a nanoscale charge detector according to claim 3 is characterized in that: Except for the first motor (1), the second motor (2) and the third motor (3), the remaining components of the non-metallic equipment are all made of non-metallic insulating materials.

5. The method for measuring the surface charge of an electric insulating component based on a nanoscale charge detector according to claim 4 is characterized in that: The total transverse length of the rocker arm (8) is not less than 60 cm.

6. The method for measuring the surface charge of an electric insulating component based on a nanoscale charge detector according to claim 5 is characterized in that: During the detection process, the first motor (1), the second motor (2) and the third motor (3) are controlled to work in coordination so that the detection head of the nanometer-level charge detector (5) is pressed against the object to be detected and the charge signal is collected. When the spring (6) is compressed to a certain extent, the switch is triggered and the third motor (3) is reversed. The detection head of the nanometer-level charge detector (5) moves away from the object to be detected. When a detection cycle is completed, the second motor (2) or the first motor (1) is driven so that the detection head of the nanometer-level charge detector (5) moves to the next detection point. The above-mentioned actions are repeated until the detection is completed.

7. The method for measuring the surface charge of an electric insulating component based on a nanoscale charge detector according to claim 6 is characterized in that: During the detection process, each time the detection of a position is completed, the induction switch (7) sends a signal to the control module, and the control module receives the signal from the induction switch (7) and controls the corresponding first motor (1), second motor (2), and third motor (3) to act alone or synchronously.

8. The method for measuring the surface charge of an electric insulating component based on a nanoscale charge detector according to claim 6 is characterized in that: The nanometer-level charge detector (5) and spring (6) assembly is movably arranged in an arc-shaped groove (16) at the end of the rocker arm (8), and by adjusting the position of the nanometer-level charge detector (5) and spring (6) assembly in the arc-shaped groove (16), it is ensured that the probe of the nanometer-level charge detector (5) can be kept vertical to the detection position of the object to be detected.

Images