Method for improving electrostatic potential measurement precision

Abstract

The invention discloses a method for improving electrostatic potential measurement precision, which comprises the following steps: S1, constructing an RC series circuit, and obtaining a current I0 according to the Kirchhoff's voltage law; s2, according to the current I0, calculating to obtain a bias current I0 (t); and S3, correcting the bias current I0 (t) to obtain an actual induction current IC (t), so as to solve the technical problems that the electrostatic potential measured by an electrostatic potential measurement sensor in the prior art is generally low in measurement precision, poor in linearity, greatly influenced by environmental temperature and humidity and cannot be measured in a high-humidity environment.

Description

Technical Field

[0001] The present application relates to the technical field of potential measurement, and in particular to a method for improving the accuracy of electrostatic potential measurement. Background Art

[0002] When the outlet hard pressure plate of the transformer substation protection panel cabinet is closed, voltage will exist on the signal line, that is, electrostatic potential. Therefore, in order to ensure that the operation and maintenance personnel can timely understand whether the outlet hard pressure plate is in the correct open / close state, it is necessary to measure the electrostatic potential of the signal line. The electrostatic potential measurement of the signal line is mainly achieved through the electrostatic potential measurement sensor. That is, the magnitude of the induced current is calculated by the measured electrostatic potential, and the measurement accuracy of the electrostatic potential measurement sensor is reflected by the magnitude of the induced current.

[0003] However, the induced current calculated by the existing electrostatic potential measurement sensor for the electrostatic potential measurement of the signal line is affected by the instantaneous bias current, so there is a certain error between the measured induced current and the actual induced current. That is, there is an error between the electrostatic potential measured by the electrostatic potential measurement sensor in the existing technology and the actual electrostatic potential. Therefore, there are technical problems such as low measurement accuracy, poor linearity, great influence by ambient temperature and humidity, and inability to measure in a high humidity environment.

[0004] Therefore, it is necessary to improve the existing electrostatic potential measurement sensor to improve the accuracy of electrostatic potential measurement. Summary of the Invention

[0005] The embodiments of the present application provide a method for improving the accuracy of electrostatic potential measurement to solve the above technical problems.

[0006] In view of this, the present application provides a method for improving the accuracy of electrostatic potential measurement, which is characterized by comprising the following steps:

[0007] S1. Build an RC series circuit and obtain the current I0 according to Kirchhoff's voltage law.

[0008] S2. Calculate the bias current I0(t) based on the current I0.

[0009] S3. Correct the bias current I0(t) to obtain the actual induced current I C (t).

[0010] Optionally, in step S1, the specific process of constructing the RC series circuit includes:

[0011] An electric field shaping plate is added to the electrostatic potential measurement sensor to obtain a measuring part of the electrostatic potential measurement sensor, wherein the measuring part consists of a measured wire core, an insulating wire sheath, an electric field shaping plate, a support column, a shielding plate, and an induction plate; the measured wire core, the insulating wire sheath, and the electric field shaping plate form a capacitor C1, the electric field shaping plate and the shielding plate form a capacitor C2, and the electric field shaping plate and the induction plate form a variable capacitor C3. The electric field shaping plate and the support column are then connected, and the support column is grounded. A resistor R1 is formed between the electric field shaping plate and the ground through FR4 material, and an RC series circuit is constructed using the capacitor C1 and the resistor R1.

[0012] Optionally, in step S1, the specific process of constructing the RC series circuit and obtaining the current I0 according to Kirchhoff's voltage law includes:

[0013] According to the constructed RC series circuit, the expression of Kirchhoff's voltage law is obtained as follows:

[0014] V=I0R1+U C1 ;

[0015] Where R1 represents the grounding resistance of the electric field shaping plate, U C1 represents the partial voltage on the capacitor formed by the signal line and the electric field shaping plate, and C1 represents the capacitor formed by the signal line and the electric field shaping plate;

[0016] Then according to the above V=I0R1+U C1 ; Get the current:

[0017]

[0018] Optionally, in step S2, the specific process of calculating the bias current I0(t) according to the current I0 includes:

[0019] According to the current The charging process is a first-order linear differential equation:

[0020]

[0021] Then the equation Solve it and get:

[0022]

[0023] Then on the above Take the derivative and according to the current The bias current is obtained as:

[0024]

[0025] Optionally, in step S3, the actual induced current I C The expression of (t) is:

[0026]

[0027] Wherein, the e is a constant.

[0028] Optionally, the electric field shaping plate is installed above the electrostatic potential measurement sensor, and support columns are provided at the four corners of the lower end of the electric field shaping plate, and the bottom ends of the support columns are in contact with the upper end surface of the induction sheet.

[0029] Optionally, the support column is a polyimide support column.

[0030] Optionally, an arc groove is provided on the upper surface of the electric field shaping plate.

[0031] Optionally, the electric field shaping plate is made of a metal conductor, the upper surface of the electric field shaping plate is an electric field capturing surface, and the lower surface is an electric field shaping surface.

[0032] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0033] The present application provides a method for improving the accuracy of electrostatic potential measurement, comprising the steps of: constructing an RC series circuit and obtaining a current I0 according to Kirchhoff's voltage law; and calculating a bias current I0(t) based on the current I0 in step S1;

[0034] S3. Correct the bias current I0(t) to obtain the actual induced current I C(t), the specific process of constructing the RC series circuit includes: adding an electric field shaping plate to the electrostatic potential measurement sensor to obtain the measuring part of the electrostatic potential measurement sensor, wherein the measuring part is composed of a measured wire core, an insulating wire skin, an electric field shaping plate, a support column, a shielding plate and a sensing plate; the measured wire core, the insulating wire skin and the electric field shaping plate constitute a capacitor C1, the electric field shaping plate and the shielding plate constitute a capacitor C2, the electric field shaping plate and the sensing plate constitute a variable capacitor C3, and then the electric field shaping plate and the supporting column are connected, the supporting column is grounded, and a resistor R1 is obtained between the electric field shaping plate and the ground through FR4 material, and then according to the measured wire core, the insulating wire skin and the electric field shaping plate constitute a capacitor C1, the electric field shaping plate and the shielding plate constitute a capacitor C2, and the electric field shaping plate and the sensing plate constitute a variable capacitor C3. The capacitor C1 and the resistor R1 form an RC series circuit, and the bias current elimination algorithm is used to remove the influence of the bias current on the measured electrostatic potential, thereby obtaining the actual induced current, thereby improving the measurement accuracy of the electrostatic potential measurement sensor, and further improving the measurement accuracy of the electrostatic potential of the signal line, ensuring that the operation and maintenance personnel can promptly understand whether the outlet hard pressure plate is in the correct open / closed state; at the same time, a larger grounding resistance is provided to further reduce the bias current, thereby preventing the weaker electrostatic potential from being weakened during measurement; thereby further improving the measurement accuracy of the electrostatic potential measurement sensor; and when the electrostatic potential is weak, the phenomenon of unmeasured will not occur, and the measurement sensitivity is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly express the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A diagram showing the steps of a method for improving the accuracy of electrostatic potential measurement provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of an electrostatic potential measurement sensor without adding an electric field shaping plate, according to a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application

[0038] Figure 3 A measurement principle diagram of an electrostatic potential measurement sensor without an additional electric field shaping plate, according to a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application;

[0039] Figure 4 A schematic structural diagram of the electric field capturing surface of an electric field shaping plate in a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application;

[0040] Figure 5A schematic structural diagram of an electric field shaping surface of an electric field shaping plate in a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application;

[0041] Figure 6 A schematic structural diagram of an electrostatic potential measurement sensor with an additional electric field shaping plate, according to a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application;

[0042] Figure 7 A schematic front view of an electrostatic potential measurement sensor with an additional electric field shaping plate, according to a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application;

[0043] Figure 8 A schematic diagram of an induced electric field of an induction sheet without an additional electric field shaping plate in a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application;

[0044] Figure 9 A schematic diagram of an induction electric field of an induction plate with an electric field shaping plate added to a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application;

[0045] Figure 10 An equivalent circuit diagram of an electrostatic potential measurement sensor with an additional electric field shaping plate, according to a method for improving electrostatic potential measurement accuracy provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0047] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. Therefore, the drawings only show the layers related to the present invention and are not drawn according to the number, shape and size ratio of the layers in actual implementation. In actual implementation, the type and number of each layer can be changed at will, and the layer layout may also be more complicated.

[0048] In the following description, numerous details are set forth to provide a more thorough explanation of the embodiments of the present invention; however, it is apparent to one skilled in the art that the embodiments of the present invention may be practiced without these specific details.

[0049] Figure 10 This is an equivalent circuit diagram for improving the accuracy of electrostatic potential measurement in this application, such as Figure 10 As shown in the figure, 110V is the signal line core voltage, R2 is the resistor used for induced current, AMP is the signal amplification circuit, and the resistor R1 formed by FR4 between the electric field shaping plate and the ground is generally 109Ω·cm. Although the resistance is large, under the induced voltage of 110V, at time t=0, there is a bias current of I0(t)=11nA. When the measured electrostatic potential electric field is weak and the amplitude of the measured actual induced current I(t) is small, only about 10nA, the measured electrostatic potential signal will be small or even disappear. Therefore, it is necessary to improve and eliminate the influence of the bias current on the measured electrostatic potential.

[0050] like Figure 1 The flowchart of a method for improving the electrostatic potential measurement accuracy in an embodiment of the present application is shown. The method for improving the electrostatic potential measurement accuracy in this embodiment includes the following steps:

[0051] S1. Build an RC series circuit and obtain the current I0 according to Kirchhoff's voltage law.

[0052] S2. Calculate the bias current I0(t) based on the current I0.

[0053] S3. Correct the bias current I0(t) to obtain the actual induced current I C (t).

[0054] Furthermore, in step S1, the specific process of constructing the RC series circuit includes:

[0055] An electric field shaping plate is added to the electrostatic potential measurement sensor to obtain a measuring part of the electrostatic potential measurement sensor, wherein the measuring part consists of a measured wire core, an insulating wire sheath, an electric field shaping plate, a support column, a shielding plate, and an induction plate; the measured wire core, the insulating wire sheath, and the electric field shaping plate form a capacitor C1, the electric field shaping plate and the shielding plate form a capacitor C2, and the electric field shaping plate and the induction plate form a variable capacitor C3. The electric field shaping plate and the support column are then connected, and the support column is grounded. A resistor R1 is formed between the electric field shaping plate and the ground through FR4 material, and an RC series circuit is constructed using the capacitor C1 and the resistor R1.

[0056] Specifically, the electrostatic potential measurement sensor without the addition of an electric field shaping plate consists of a shielding plate, an induction plate, a motor rotor and a signal processing circuit board. The motor rotor drives the shielding plate to rotate, thereby periodically blocking the electric field, causing the induction plate to generate a periodic current, which is then converted, amplified and processed by the signal processing circuit board to calculate the electrostatic potential of the measured signal line.

[0057] Specifically, the measurement principle of the electrostatic potential measurement sensor without the electric field shaping plate is as follows:

[0058] The electrostatic potential measurement sensor without an electric field shaping plate is composed of two metal plates coaxially mounted on the motor output shaft, namely a shielding plate and a sensing plate. The shielding plate is arranged above the sensing plate, rotates stably with the motor output shaft, and blocks the electric field lines by grounding. The sensing plate is fixed below the shielding plate and is insulated from the motor output shaft. When the grounded shielding plate rotates at a constant speed with the motor output shaft, the sensing plate placed in the electric field will be partially blocked by the shielding plate, and the blocked area changes periodically. Let the area of ​​the sensing plate exposed to the electric field be recorded as S1, and the other part shielded by the shielding plate be recorded as S2. If the field strength of the DC electric field generated by the electrostatic potential of the measured signal line is E, then the dielectric constant of air is ε. When the influence of the edge effect on the electric field is not considered, the amount of charge induced on the sensing plate Q(t) can be expressed as:

[0059] Q(t)=εES1(t);

[0060] According to Q(t) = εES1(t), by taking the derivative of Q(t), we can get the electric field induced current i(t):

[0061]

[0062] As the shielding plate rotates, It changes periodically, so i(t) also changes periodically, and its amplitude is proportional to the electric field strength E, thereby realizing the measurement of electrostatic potential.

[0063] Furthermore, in step S1, the specific process of constructing the RC series circuit and obtaining the current I0 according to Kirchhoff's voltage law includes:

[0064] According to the constructed RC series circuit, the expression of Kirchhoff's voltage law is obtained as follows:

[0065] V=I0R1+U C1 ;

[0066] Where R1 represents the grounding resistance of the electric field shaping plate, U C1 represents the partial voltage on the capacitor formed by the signal line and the electric field shaping plate, and C1 represents the capacitor formed by the signal line and the electric field shaping plate;

[0067] Then according to the above V=I0R1+U C1 , get the current:

[0068]

[0069] Furthermore, in step S2, the specific process of calculating the bias current I0(t) based on the current I0 includes:

[0070] According to the current The charging process is a first-order linear differential equation:

[0071]

[0072] Then the equation Solve it and get:

[0073]

[0074] Then the above Take the derivative and calculate the current Get the bias current:

[0075]

[0076] According to the above Calculate and get:

[0077]

[0078] According to the above Calculate and get the bias current:

[0079]

[0080] Furthermore, the upper surface of the electric field shaping plate is provided with an arc groove. The electric field shaping plate is made of a metal conductor. The upper surface of the electric field shaping plate serves as the electric field capture surface, while the lower surface serves as the electric field shaping surface. Specifically, the electric field shaping plate is made of aluminum alloy, and a 3mm arc groove is designed on its upper surface, which serves as the electric field capture surface. It wraps around a 1.5 square millimeter RV multi-strand soft core signal line to prevent displacement of the signal line and simultaneously capture the electric field of the surface signal line. The lower surface of the electric field shaping plate is a complete plane, serving as the electric field shaping surface, providing a shaped electric field for the electric field sensing plate below. The electric field shaping plate is installed above the electrostatic potential measurement sensor, shapes the electric field of the measured signal line, and then transmits it to the electrostatic potential measurement sensor for potential measurement.

[0081] Furthermore, the process of comparing the electrostatic potential measurement sensor without the electric field shaping plate and the electrostatic potential measurement sensor with the electric field shaping plate is as follows:

[0082] First, the induced current of the signal line measured by the electrostatic field measurement sensor without adding an electric field shaping plate is analyzed as follows:

[0083] To simplify the calculation and not hinder the solution, assume that the charge on the signal line core is q and its diameter is ignored; the dielectric strength of the signal line insulation is ε1 and the radius is r; the induction plate of the electrostatic potential measurement sensor is located at a distance R from the outer insulation of the signal line, as shown in the figure. Figure 2 and Figure 8 As shown:

[0084] According to Gauss's law in the electric field and the boundary conditions at the junction of two media:

[0085]

[0086] Inside the insulating dielectric layer are:

[0087]

[0088] Outside the insulating dielectric layer are:

[0089]

[0090] Due to the existence of the dielectric layer, the equivalent charge qeff is corrected by the dielectric constant as follows:

[0091]

[0092] Will Bring in We can get:

[0093]

[0094] According to the above It can be deduced that without adding the electric field shaping plate, the electric field induced current is:

[0095]

[0096] Secondly, the induced current of the signal line measured by the electrostatic field measurement sensor is analyzed and calculated when the electric field shaping plate is added:

[0097] The parameters are consistent with those when no electric field shaping plate is added. Assume that the charge of the signal line core is q and its diameter is ignored; the dielectric strength of the signal line insulation is ε1 and the radius is r; the induction plate of the electrostatic potential measurement sensor is located at a distance R from the outer insulation of the signal line, as shown in Figure 6 and Figure 9 As shown:

[0098] Assume that the surface potential of the signal line insulation is for:

[0099]

[0100] Due to the addition of the electric field shaping plate made of metal conductor, the free electrons inside it can move freely. When the external electric field acts on the metal, the free electrons inside the conductor will redistribute until the electric field inside the conductor is completely offset. Therefore, the electric field shaping plate is an equipotential body. When electrostatic equilibrium is achieved, the electric potential of the electric field shaping plate is equal everywhere.

[0101] Therefore, the electric potential of the electric field capturing surface and the electric field shaping surface of the electric field whole plate is the same as Since the electric field shaping surface at the bottom of the electric field shaping plate is a conductor and an equipotential surface, the electric field is distributed along its normal direction, forming a uniform electric field between it and the electric field measurement sensor. The electric field strength can be expressed as:

[0102]

[0103] Wherein, d is the distance between the electric field shaping plate and the electric field measurement sensor. And the solution equation of i(t) can be used to obtain the electric field induced current of the electrostatic potential measurement sensor:

[0104]

[0105] Finally, the magnitude of the electric field induced current with and without the electric field shaping plate is compared as follows:

[0106] Compare the electric field induced currents of the two and then do the quotient to get:

[0107]

[0108] In actual engineering applications, due to processing technology limitations, r = d, and R>>2r. Considering the air dielectric constant ε1 = 1, we get:

[0109]

[0110] Therefore, it can be seen that the ratio of the induced current after adding the electric field shaping plate to the induced current without the electric field shaping plate is much greater than 1. Therefore, the induced current measured after adding the electric field shaping plate is significantly increased, which reflects that the measurement accuracy of the electrostatic potential measurement sensor is improved.

[0111] Furthermore, the electric field shaping plate is installed above the electrostatic potential measurement sensor, and support columns are provided at the four corners of the lower end of the electric field shaping plate. The bottom ends of the support columns are in contact with the upper end surface of the sensor sheet, and the support columns are polyimide support columns.

[0112] Specifically, in order to further improve the measurement accuracy of the electrostatic potential measurement sensor, it is necessary to reduce the bias current. Therefore, polyimide support columns with better insulation performance are selected for the four support columns of the electric field shaping plate. The polyimide support columns usually have an insulation resistance of 1012Ω·cm, thereby reducing the influence of the current i0 on the induced current i(t). The polyimide support columns are located at the bottom of the electric field shaping plate, as shown in FIG. Figure 5 and Figure 6 shown.

[0113] The purpose of eliminating bias current is achieved by arranging a polyimide pillar between the electric field shaping plate and the sensing plate of the electrostatic potential measurement sensor.

[0114] Specifically, first, a circuit model for bias current generation during electrostatic potential measurement is established.

[0115] After adding the electric field shaping plate, the measuring part of the electrostatic potential measurement sensor is composed of the measured signal line core, insulating wire sheath, electric field shaping plate, supporting column, shielding plate and induction plate;

[0116] Among them, the signal line core, insulation wire skin and electric field shaping plate constitute capacitor C1; the electric field shaping plate and shielding plate constitute capacitor C2; the electric field shaping plate and induction plate constitute variable capacitor C3; at the same time, because the electric field shaping plate is connected to the support column, and the support column is grounded, the electric field shaping plate and the ground form resistor R1 through the FR4 material. Its equivalent circuit diagram is as follows Figure 10 As shown;

[0117] In the equivalent circuit diagram, 110V is the signal line core voltage; R2 is the resistor used for induced current; AMP is the signal amplification circuit. The resistor R1 formed by FR4 between the electric field shaping plate and the ground is generally 109Ω·cm. Although the resistance is large, under the induced voltage of 110V, at time t=0, there is a bias current of I0(t)=11nA. When the measured electrostatic potential electric field is weak and the measured induced current I(t) has a small amplitude of only about 10nA, the measured electrostatic potential signal will be small or even disappear.

[0118] Secondly, an algorithm for eliminating the bias current is established. According to the equivalent circuit, it can be seen that in the RC series circuit composed of C1 and R1, Kirchhoff's voltage law is satisfied:

[0119] V=I0R1+U C1 ;

[0120] Where R1 represents the grounding resistance of the electric field shaping plate, U C1 represents the partial voltage on the capacitor formed by the signal line and the electric field shaping plate, and C1 represents the capacitor formed by the signal line and the electric field shaping plate;

[0121] According to V=I0R1+U C1 , and then the current is:

[0122]

[0123] According to the current The charging process is a first-order linear differential equation:

[0124]

[0125] Then the equation Solve it and get:

[0126]

[0127] Then the above Take the derivative and calculate the current get:

[0128]

[0129] According to the above Calculate and get:

[0130]

[0131] According to the above Calculate and get the bias current:

[0132]

[0133] By correcting I0(t), the corrected induced current I is obtained. C (t) is:

[0134] I C (t)=I(t)+I0(t)

[0135] Right now

[0136]

[0137] Wherein, said e is a constant;

[0138] Where V = 110V, R1 and C1 can be measured by experiment, that is, generally R1 = 109Ω, C1 = 10pF, through the By calculation, it is concluded that the influence of bias current on the measured induced current can be eliminated, thereby improving the measurement accuracy of the electrostatic potential measurement sensor.

[0139] Finally, the effect of bias current can be further reduced from the hardware perspective:

[0140] By formula It can be seen that increasing R1 can significantly reduce the bias current I0(t). When using polyimide pillars, its R1 = 1012Ω, which is much higher than the resistance formed by FR4. In this case, the bias current I0(t) is much smaller than the electric field induced current. At the same time, using the formula Calculation can completely eliminate the influence of bias current on electrostatic potential measurement.

[0141] Therefore, the measurement accuracy of the electrostatic potential measurement sensor is improved, and then the measurement accuracy of the electrostatic potential of the signal line is improved, ensuring that the operation and maintenance personnel can promptly understand whether the outlet hard pressure plate is in the correct open / closed state; at the same time, a larger grounding resistance is provided to further reduce the bias current, avoiding the weakening of the weak electrostatic potential signal during measurement; so that the measurement accuracy of the electrostatic potential measurement sensor is further improved; and when the electrostatic potential signal is weak, the phenomenon of unmeasured will not occur, and the measurement sensitivity is further improved.

[0142] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0143] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for improving the accuracy of electrostatic potential measurement, characterized in that: The following steps are involved: S1. Build an RC series circuit and obtain the current I0 according to Kirchhoff's voltage law. S2. Calculate the bias current I0(t) based on the current I0. S3. Correct the bias current I0(t) to obtain the actual induced current I C (t).

2. A method for improving electrostatic potential measurement accuracy according to claim 1, characterized in that: In step S1, the specific process of constructing the RC series circuit includes: An electric field shaping plate is added to the electrostatic potential measurement sensor to obtain a measuring part of the electrostatic potential measurement sensor, wherein the measuring part consists of a measured wire core, an insulating wire sheath, an electric field shaping plate, a support column, a shielding plate, and an induction plate; the measured wire core, the insulating wire sheath, and the electric field shaping plate form a capacitor C1, the electric field shaping plate and the shielding plate form a capacitor C2, and the electric field shaping plate and the induction plate form a variable capacitor C3. The electric field shaping plate and the support column are then connected, and the support column is grounded. A resistor R1 is formed between the electric field shaping plate and the ground through FR4 material, and an RC series circuit is constructed using the capacitor C1 and the resistor R1.

3. A method for improving electrostatic potential measurement accuracy according to claim 2, characterized in that: In step S1, the specific process of constructing an RC series circuit and obtaining the current I0 according to Kirchhoff's voltage law includes: According to the constructed RC series circuit, the expression of Kirchhoff's voltage law is obtained as follows: V=I0R1+U C1 ; Where R1 represents the grounding resistance of the electric field shaping plate, U C1 represents the partial voltage on the capacitor formed by the signal line and the electric field shaping plate, and C1 represents the capacitor formed by the signal line and the electric field shaping plate; Then according to the above V=I0R1+U C1 ; Get the current:

4. A method for improving electrostatic potential measurement accuracy according to claim 3, characterized in that: In step S2, the specific process of calculating the bias current I0(t) based on the current I0 includes: According to the current The charging process is a first-order linear differential equation: Then the equation Solve it and get: Then the above Take the derivative and according to the current The bias current is obtained as:

5. A method for improving electrostatic potential measurement accuracy according to claim 4, characterized in that: In step S3, the actual induced current I C The expression of (t) is: Wherein, the e is a constant.

6. A method for improving electrostatic potential measurement accuracy according to claim 2, characterized in that: The electric field shaping plate is installed above the electrostatic potential measurement sensor. Support columns are provided at the four corners of the lower end of the electric field shaping plate. The bottom ends of the support columns are in contact with the upper end surface of the induction sheet.

7. A method for improving electrostatic potential measurement accuracy according to claim 6, characterized in that: The support column is a polyimide support column.

8. A method for improving electrostatic potential measurement accuracy according to claim 2, characterized in that: The upper surface of the electric field shaping plate is provided with an arc groove.

9. A method for improving electrostatic potential measurement accuracy according to claim 8, characterized in that: The electric field shaping plate is made of a metal conductor, the upper surface of the electric field shaping plate is an electric field capturing surface, and the lower surface is an electric field shaping surface.

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