Self-calibration method of insulator voltage measuring device and related device

Abstract

The invention relates to the technical field of voltage measurement of a power system, and discloses a self-calibration method of an insulator voltage measuring device and a related device, the insulator voltage measuring device is electrically connected with a power transmission line, and the method comprises the following steps: acquiring multiple groups of voltage data of a low-voltage arm capacitor of the insulator voltage measuring device collected in multiple impedance states; based on a capacitance voltage division principle and a circuit impedance conversion relation, carrying out capacitance and voltage calculation by utilizing multiple groups of voltage data to obtain a high-voltage arm capacitance value and a power transmission line voltage of the insulator voltage measuring device; and according to the capacitance value of the high-voltage arm, carrying out self-calibration on the partial pressure ratio to obtain the calibrated partial pressure ratio of the insulator voltage measuring device. By means of the mode, the real-time high-voltage arm capacitance value of the insulator voltage measuring device can be obtained, the capacitance value change can be calibrated, the voltage of the power transmission line and the voltage division ratio after calibration can be obtained, the problem that voltage measurement errors are caused due to the fact that the voltage division capacitance value is unstable is solved, and the voltage measurement accuracy is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system voltage measurement, and particularly relates to a self-calibration method of an insulator voltage measurement device and a related device. BACKGROUND

[0002] Under the development trend of the integration of smart grid and distribution network primary and secondary devices, as a key insulating support device in the power system, the accurate monitoring of the operating state of the insulator is crucial to the safety of the power grid. Voltage measurement is one of the core parameters for the state evaluation of the insulator, and accurate voltage measurement can provide key data support for power metering, relay protection, and overvoltage monitoring. Although the traditional electromagnetic voltage transformer has high accuracy, it has problems such as large size, complex insulation structure, narrow frequency band, and risk of ferromagnetic resonance, and is difficult to meet the needs of modern distribution network miniaturization and intelligentization. The non-intrusive voltage measurement technology based on the principle of electric field coupling has become an important development direction for insulator voltage measurement due to its low insulation difficulty, simple structure, and convenient installation.

[0003] In the insulator voltage measurement technology, the non-intrusive measurement method based on the principle of capacitive voltage division is widely used due to its simple structure and good insulation performance. By implanting a voltage sensing unit inside the insulator, the coupling capacitance formed between the electrodes is used to measure the voltage to be measured. The high-voltage signal is converted into a low-voltage signal through the coupling capacitance, and the low-voltage signal is transmitted to the back-end processing circuit. The measurement does not depend on the magnetic core and inductive winding and does not require complex insulation structure, and has a wider measurement bandwidth and dynamic range, with the advantages of small size, low cost, and convenient installation.

[0004] This method uses high-voltage arm capacitance C1 (coupling capacitance between the insulator and the transmission conductor) and low-voltage arm capacitance C2 (coupling capacitance between the insulator and the ground) to form a voltage division circuit, converting the high-voltage signal into a measurable low-voltage signal.

[0005] However, in general, the coupling capacitances C1 and C2 between the sensing units inside the insulator are controlled by mold precision and vacuum casting process. During the processing, the insulator voltage sensor prototype may cause the dielectric constant of the filled insulating medium to be unequal due to the incomplete consistency of the outdoor epoxy resin material raw materials, or the coupling capacitance value between the sensing units of different sensor prototypes may deviate due to the incomplete centering of the implanted sensing units during the processing. In actual application, the non-contact voltage sensor based on electric field coupling is affected by factors such as environmental temperature and humidity, insulator surface contamination, changes in the distance between the sensor and the conductor, and long-term operation aging, resulting in unstable voltage division capacitance value, and further causing voltage measurement error. Traditional methods are difficult to calibrate the capacitance change in real time, and a high-precision measurement technology capable of calibrating the capacitance value change is urgently needed. SUMMARY

[0006] The main purpose of the present application is to provide a self-calibration method of insulator voltage measuring device and related device, which can solve the problem of unstable voltage measurement error caused by unstable voltage measurement error in the prior art.

[0007] To achieve the above-mentioned purpose, the first aspect of the present application provides a self-calibration method of insulator voltage measuring device, the insulator voltage measuring device is electrically connected with the transmission line, and the method comprises: Obtaining a plurality of groups of voltage data of the low-voltage arm capacitor of the insulator voltage measuring device collected under a plurality of impedance states; Based on the capacitor voltage division principle and the circuit impedance transformation relationship, the capacitor and voltage are calculated by using a plurality of groups of voltage data to obtain the high-voltage arm capacitor value and the transmission line voltage of the insulator voltage measuring device; According to the self-calibration of the voltage division ratio of the high-voltage arm capacitor value, the calibrated voltage division ratio of the insulator voltage measuring device is obtained.

[0008] In a feasible implementation manner, based on the capacitor voltage division principle and the circuit impedance transformation relationship, the capacitor and voltage are calculated by using a plurality of groups of voltage data to obtain the high-voltage arm capacitor value and the transmission line voltage of the insulator voltage measuring device, comprising: Based on the capacitor voltage division principle and the circuit impedance transformation relationship, a target equation group is established by using a plurality of groups of voltage data, the unknowns of the target equation group include the high-voltage arm capacitor value and the transmission line voltage; Solving the target equation group to obtain the high-voltage arm capacitor value and the transmission line voltage.

[0009] In a feasible implementation manner, the plurality of impedance states at least include a first impedance state and a second impedance state, the plurality of groups of voltage data include first voltage data under the first impedance state and second voltage data under the second impedance state, and the target equation group is established by using a plurality of groups of voltage data based on the capacitor voltage division principle and the circuit impedance transformation relationship, comprising: The first equation under the first impedance state is established by using the first voltage data and the capacitor voltage division principle and the circuit impedance transformation relationship; The second equation under the second impedance state is established by using the second voltage data and the capacitor voltage division principle and the circuit impedance transformation relationship.

[0010] In a feasible implementation manner, the first equation comprises: ; In the formula, U O 1 is the first voltage data, U iU is a transmission line voltage, C1 is a high-voltage arm capacitance value, C2 is a low-voltage arm capacitance value, and C3 is a voltage dividing capacitance in a first impedance state.

[0011] In an implementable implementation, the second equation comprises: ; In the formula, U O 2 is first voltage data, U U i U is a transmission line voltage, C1 is a high-voltage arm capacitance value, C2 is a low-voltage arm capacitance value, and C4 is a voltage dividing capacitance in a second impedance state.

[0012] In an implementable implementation, the high-voltage arm capacitance value comprises: ; In the formula, U O 1 is first voltage data, U O 2 U is a transmission line voltage, C1 is a high-voltage arm capacitance value, C2 is a low-voltage arm capacitance value, C3 is a voltage dividing capacitance in a first impedance state, and C4 is a voltage dividing capacitance in a second impedance state.

[0013] In an implementable implementation, the transmission line voltage comprises: ; In the formula, U O 1 is first voltage data, U O 2 is second voltage data, U i U is a transmission line voltage, C2 is a low-voltage arm capacitance, C3 is a voltage dividing capacitance in a first impedance state, and C4 is a voltage dividing capacitance in a second impedance state.

[0014] To achieve the above object, the second aspect of the present application provides a self-calibration device of an insulator voltage measurement device, the insulator voltage measurement device being electrically connected with a transmission line, and the self-calibration device comprising: a data acquisition module configured to acquire a plurality of groups of voltage data of a low-voltage arm capacitance of the insulator voltage measurement device collected in a plurality of impedance states; a data solving module configured to perform capacitance and voltage solving based on a capacitance voltage dividing principle and a circuit impedance transformation relationship by using the plurality of groups of voltage data, to obtain a high-voltage arm capacitance value of the insulator voltage measurement device and a transmission line voltage; a data calibration module configured to perform self-calibration of a voltage dividing ratio according to the high-voltage arm capacitance value, to obtain a calibrated voltage dividing ratio of the insulator voltage measurement device.

[0015] To achieve the above object, the third aspect of the present application provides a computer readable storage medium, which stores a computer program, and the computer program, when executed by a processor, causes the processor to perform the steps of the first aspect and any possible implementation.

[0016] To achieve the above object, the fourth aspect of the present application provides a computer device, which comprises a memory and a processor, and the memory stores a computer program, and the computer program, when executed by the processor, causes the processor to perform the steps of the first aspect and any possible implementation.

[0017] The embodiment of the present application has the following beneficial effects: The present application provides a kind of self-calibration method of insulator voltage measuring device, insulator voltage measuring device is electrically connected with transmission line, the method comprises: obtaining the multiple sets of voltage data of the low voltage arm capacitor of the insulator voltage measuring device collected in multiple impedance states;Based on the principle of capacitance voltage division and circuit impedance transformation relationship, capacitance and voltage are solved using multiple sets of the voltage data, the high voltage arm capacitance value of the insulator voltage measuring device and transmission line voltage are obtained;According to the high voltage arm capacitance value, the self-calibration of voltage division ratio is carried out, and the calibrated voltage division ratio of the insulator voltage measuring device is obtained.By the above-mentioned mode, the multiple sets of voltage data of the low voltage arm capacitor of the insulator voltage measuring device in multiple impedance states are collected, capacitance and voltage are solved using the principle of capacitance voltage division and circuit impedance transformation relationship and voltage data, not only the real-time high voltage arm capacitance value of the insulator voltage measuring device can be obtained, the capacitance value change can be calibrated, transmission line voltage and calibrated voltage division ratio can also be obtained, the problem of unstable voltage measurement error caused by unstable voltage division capacitance value is reduced, and the voltage measurement accuracy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0019] Among them: Figure 1 The flow chart of the self-calibration method of the insulator voltage measuring device in the embodiment of the present application is shown in the figure. Figure 2 The overall block diagram of the self-calibration system of the insulator voltage measuring device in the embodiment of the present application is shown in the figure. Figure 3It is a sectional view of a self-calibration system of an insulator voltage measuring device in an embodiment of the present application. Figure 4 It is an equivalent circuit diagram of an insulator voltage measuring device in an embodiment of the present application. Figure 5 It is an equivalent circuit diagram of a self-calibration system of an insulator voltage measuring device in an embodiment of the present application. Figure 6 It is another flow chart of a self-calibration method of an insulator voltage measuring device in an embodiment of the present application. Figure 7 It is a structural block diagram of a self-calibration device of an insulator voltage measuring device in an embodiment of the present application. Figure 8 It is a structural block diagram of a computer device in an embodiment of the present application. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] Please refer to Figure 1 , Figure 1 It is a flow chart of a self-calibration method of an insulator voltage measuring device in an embodiment of the present application, which realizes an intelligent insulator voltage measuring device self-calibration method based on impedance transformation. The self-calibration method is applied to a self-calibration system of an insulator voltage measuring device. Please refer to Figure 2 and Figure 3 , Figure 2 It is a whole block diagram of a self-calibration system of an insulator voltage measuring device in an embodiment of the present application. Figure 3 It is a sectional view of a self-calibration system of an insulator voltage measuring device in an embodiment of the present application, wherein the system shown in Figure 2 includes an insulator voltage measuring device, an impedance transformation self-calibration circuit, a back-end signal conditioning circuit and a wireless acquisition unit. The impedance transformation self-calibration circuit can include the impedance transformation unit and the single-chip microcomputer control unit shown in the present application. The insulator voltage measuring device, the impedance transformation circuit, the back-end signal conditioning circuit and the wireless acquisition unit are communicatively connected. The single-chip microcomputer control unit is used for controlling the switch array, collecting data and executing calibration algorithms. The back-end conditioning circuit is used for signal attenuation, protection and conditioning.

[0022] Among them, Figure 2The system shown adds an impedance transformation self-calibration circuit compared with the function of a traditional insulator, and the influence of the coupling capacitor can be eliminated through impedance transformation, so that the to-be-measured voltage can be measured more accurately. The impedance transformation self-calibration circuit can be realized by connecting an electronic element with a voltage dividing capability in parallel to the insulator voltage measurement device, and the electronic element can be a capacitor or an inductor, which is not limited here. Since two parameters, i.e., the high-voltage arm capacitor and the transmission line voltage, need to be solved in the calibration process, at least two equation groups are needed, and at least two impedance states are needed to establish two equations and solve two unknowns.

[0023] Further, Figure 3 A sectional view of a self-calibration system of an insulator voltage measurement device in an embodiment of the present application is shown in FIG. 1. Figure 3 The self-calibration system shown includes an insulator voltage measurement device 1, an impedance transformation unit (not shown), and a single-chip microcomputer control unit (not shown).

[0024] The insulator voltage measurement device 1 includes a high-voltage terminal 2, a first floating electrode 5, a second floating electrode 4, an internal chamber 9, and a low-voltage arm capacitor 10. The first floating electrode is an inductive electrode, and the second floating electrode is a grounded electrode. The high-voltage terminal 2, the first floating electrode 5, the second floating electrode 4, and the internal chamber 9 are used to be placed inside the insulator. The first floating electrode 5 and the high-voltage terminal 2 form a high-voltage arm capacitor C1. The first floating electrode 5 is welded on a first PCB board 7 of the second floating electrode 4. The first PCB board 7 is connected to the internal chamber 9 and connected to the low-voltage arm capacitor 10. The low-voltage arm capacitor 10 is welded on a second PCB board 11. The high-voltage terminal and the first floating inductive electrode form a coupling capacitor, i.e., a high-voltage arm capacitor C1. A patch capacitor, i.e., a low-voltage arm capacitor C2, is installed in the internal chamber. The transmission line voltage is converted into a low-voltage signal through the series connection of C1 and C2, and the generated low-voltage signal is transmitted to a wireless acquisition unit.

[0025] Further, in the voltage measurement device of the present application, the high-voltage arm capacitor C1 will drift in capacitance value due to time change, resulting in a deviation of the voltage dividing ratio. The estimation of the coupling capacitor and the calibration of the voltage dividing ratio are the key to the design of the sensor. The present application proposes an improved intelligent insulator capacitor voltage measurement method, in which a sampling capacitor is connected in parallel between the two electrodes of the sensor. By changing the size of the sampling capacitor, a set of equations is established, and the coupling capacitor and the to-be-measured voltage are solved simultaneously, realizing a self-calibration method based on impedance transformation.

[0026] A sampling capacitor is connected in parallel across the low-voltage arm capacitor C2 of the smart insulator voltage sensor, and the connection and switching of the sampling capacitor are controlled by a switch array; the low-voltage arm capacitor output voltages when the sampling switch is disconnected and the sampling capacitor is connected are used to establish an equation set; the high-voltage arm capacitor value and the voltage to be measured are solved by simultaneously solving the equation set; the digital gain of the back-end conditioning circuit is adjusted according to the high-voltage arm capacitor value obtained by the solution, so as to realize the calibration of the division ratio. The sampling capacitor includes a plurality of capacitors (such as C3 and C4) with different values, which are switched into the circuit by the switch array.

[0027] The impedance conversion unit is connected in parallel between the first floating electrode 5 and the second floating electrode 4; the power transmission line is connected with the high-voltage terminal 2, and the second PCB board 11 is in communication connection with the single-chip microcomputer control unit; the impedance conversion unit is used for switching different impedance states; the single-chip microcomputer control unit is used for executing the self-calibration method shown in the present application, and eliminating the influence of the coupling capacitor in time.

[0028] As shown in the various structures of the insulator voltage measurement device 1, Figure 3 As shown in the various structures of the insulator voltage measurement device 1,

[0029] In a feasible implementation manner, the impedance conversion unit includes at least two groups of parallel-connected voltage division units; the single-chip microcomputer control unit is further used for controlling whether the voltage division unit participates in voltage division, so as to switch different impedance states. The voltage division unit includes a voltage division capacitor and a switch connected in series, and the single-chip microcomputer control unit is further used for controlling whether the sampling capacitor participates in voltage division through the switch, so as to switch different impedance states.

[0030] Exemplarily, the voltage dividing capabilities of each group of voltage dividing units are different, so that multiple equations can be constructed to solve multiple unknowns when constructing the equation set subsequently. The voltage dividing unit can be a capacitor, an inductor, or other electronic components with voltage dividing capability. The application takes a capacitor as an example of a voltage dividing element. The voltage dividing unit can include a voltage dividing capacitor and a switch connected in series. The single-chip microcomputer control unit is further configured to control whether the sampling capacitor participates in voltage division through the switch to switch different impedance states. For example, two voltage dividing units are selected. The voltage dividing unit 1 can have a voltage dividing capacitor C3 and a switch S1. The other voltage dividing unit can have a voltage dividing capacitor C4 and a switch S2. The original state is that the switches are in an open state. When the first voltage data of the first impedance state needs to be collected, S1 is closed to allow C3 to participate in voltage division, and the first voltage data is collected. When the second voltage data of the second impedance state needs to be collected, S2 is closed to allow C4 to participate in voltage division, and the second voltage data is collected.

[0031] The single-chip microcomputer control unit can be an STM32G431CBU6 single-chip microcomputer integrated with an A / D conversion and a digital signal processing function.

[0032] It should be noted that the intelligent insulator voltage measurement method described in the application has the same voltage measurement principle as the two coupling capacitor voltage division of the traditional insulator. The voltage sensing unit described includes a high-voltage arm capacitor and a low-voltage arm capacitor to form a voltage dividing circuit. The line voltage is divided by the series connection of the high-voltage arm capacitor and the low-voltage arm capacitor, and Uo = C1 / (C1+C2)Ui, where Uo is the low voltage transmitted to the rear-end circuit, and Ui is the line voltage. However, in the measurement of the two coupling capacitor voltage division of the traditional insulator, the voltage division ratio K = (C1+C2) / C1 (simplified model) is easily affected by various factors: (1) Process deviation: During the processing of the insulator voltage sensor prototype, the C1 and C2 coupling capacitance values of different insulators may deviate due to the following conditions: the outdoor epoxy resin material raw material ratio is not completely consistent, there are bubbles in the packaging (resulting in different dielectric constants of the filled insulating medium), and the implanted sensing unit is not completely centered, which affects the consistency of the voltage division ratio.

[0033] (2) Environmental temperature and humidity changes: The dielectric constant of the insulating medium (such as air and insulator material) changes with the fluctuation of temperature and humidity, causing the capacitance values of C1 and C2 to drift, directly affecting the stability of the voltage division ratio.

[0034] (3) Insulator surface contamination: Contamination deposition can introduce additional stray capacitance, change the electric field distribution, and interfere with the coupling characteristics of C1 and C2, increasing the measurement error.

[0035] (4) Sensor installation deviation: the change of the distance between the sensor and the transmission conductor, the mechanical vibration of the installation position, etc. can cause the coupling capacitance value of C1 to be unstable, further exacerbating the fluctuation of the voltage division ratio.

[0036] (5) Aging of the internal capacitor of the insulator: during long-term operation, the internal insulating medium (such as epoxy resin) of the insulator is affected by factors such as electric field, temperature, mechanical stress, etc., and degrades, causing the dielectric constant to gradually change, which causes the capacitance values of C1 and C2 to slowly drift over time, the stability of the voltage division ratio decreases, and the long-term measurement accuracy is affected.

[0037] For the traditional voltage division capacitor design, the integration is low, the anti-interference is poor, and it cannot meet the high-precision requirements of the smart grid. The high-voltage arm capacitor C1 (the coupling capacitor between the measured line and the sensor) is affected by factors such as line diameter, insulation thickness, distance between sensor and conductor, temperature and humidity, etc. The self-calibration method using impedance change is used to correct the high-voltage arm capacitor C1, and the parallel switchable calibration capacitor group between the sensing electrode and the grounding electrode is used. It contains two calibration capacitors C3 and C4 with different capacitance values, and the equivalent coupling capacitance value C1 of C1 is solved in real time. By controlling the access through a relay or an electronic switch, the influence of environmental factors is eliminated. By switching control, the output voltages Uo1 and Uo2 when different calibration capacitors are accessed are collected, and based on the measurement data, a system of equations is established to solve the actual equivalent coupling capacitance value C1 and the measured voltage, and the voltage division ratio is calibrated. By switching the calibration capacitor, the equivalent capacitance C1 and Ui under the current environment are calculated in real time, eliminating the influence of factors such as line spacing changes, temperature and humidity fluctuations on C1, and ensuring the calculation accuracy of the voltage division ratio.

[0038] The traditional C2 uses discrete capacitors, which are easily affected by electromagnetic interference, mechanical vibration and environmental temperature and humidity, and the capacitance drift causes the voltage division ratio to be unstable. In this invention, high-precision, low-temperature chip capacitors are used to replace the capacitors formed by the coupling of the sensing electrode and the grounding shielding electrode, which are integrated on the PCB board and packaged in the grounding shielding cavity, and are isolated from external interference.

[0039] The bottom grounding shielding cavity design is to open an independent cylindrical cavity at the lower part of the insulator body, the inner wall of which is coated with a copper or other metal shielding layer and is connected to the grounding shielding second floating electrode through a grounding pin to achieve reliable grounding and form a Faraday cage structure to shield external electromagnetic interference; the PCB board is fixed in the cavity through a shockproof support, and the cavity is filled with an insulating sealing material such as epoxy resin to improve the anti-interference ability and environmental adaptability of the chip capacitor and the rear-end circuit.

[0040] The application has the beneficial effects that: the application adopts impedance conversion self-calibration for the high-voltage arm capacitor C1, replaces the low-voltage arm capacitor C2 with a high-precision patch capacitor, and optimizes the structure by cooperating with a ground shielding cavity, thereby improving the precision of voltage measurement of the insulator; meanwhile, the insulator has a compact and integrated design, the installation mode is consistent with that of a traditional insulator and no additional insulation treatment is needed, thereby meeting the demand for high-precision voltage measurement of the insulator under the complex environment of a smart grid.

[0041] Please continue to refer to Figure 1 , and the self-calibration method of the application will be described in detail below, as shown in Figure 1 The self-calibration method of the insulator voltage measurement device includes the following steps: 101. acquiring a plurality of groups of voltage data of the low-voltage arm capacitor of the insulator voltage measurement device collected under a plurality of impedance states; It should be noted that the insulator voltage measurement device is electrically connected with the power transmission line, specifically, it can be connected with the high-voltage line, and the high-voltage terminal is connected with the high-voltage line to collect the high-voltage signal, so as to measure the voltage of the high-voltage line in real time. In order to facilitate measurement, generally, the line voltage is converted into a low-voltage signal by a capacitor voltage divider and transmitted to the rear-end circuit.

[0042] In order to reduce the voltage measurement error, the application collects a plurality of groups of voltage data Uo of the low-voltage arm capacitor of the insulator voltage measurement device under a plurality of impedance states, that is, collects a plurality of groups of low-voltage signals, and performs self-calibration processing based on the plurality of groups of voltage data Uo.

[0043] For example, the plurality of impedance states can be realized by the above-mentioned impedance conversion unit, and different impedance states can be switched by the impedance conversion unit.

[0044] 102. based on the capacitor voltage division principle and the circuit impedance conversion relationship, the plurality of groups of voltage data are used to solve the capacitor and voltage, and the high-voltage arm capacitor value and the power transmission line voltage of the insulator voltage measurement device are obtained; Further, after obtaining the plurality of groups of voltage data, the capacitor and voltage can be solved based on the capacitor voltage division principle and the circuit impedance conversion relationship, and the high-voltage arm capacitor value and the power transmission line voltage of the insulator voltage measurement device are obtained.

[0045] Specifically, step 102 includes the following steps A01 to A02: A01. based on the capacitor voltage division principle and the circuit impedance conversion relationship, a plurality of groups of voltage data are used to establish a target equation group, and the unknowns of the target equation group include the high-voltage arm capacitor value and the power transmission line voltage; It can be understood that a relationship between the capacitance and the voltage can be established based on a capacitance voltage division principle and a circuit impedance conversion relationship, a target equation set is established based on the relationship, and unknown quantities include a high-voltage arm capacitance value and a transmission line voltage. The equation set includes at least two equations to solve two unknown quantities.

[0046] The plurality of impedance states at least include two impedance states: a first impedance state and a second impedance state, the plurality of sets of voltage data include first voltage data in the first impedance state and second voltage data in the second impedance state, and step A01 includes: a first equation in the first impedance state is established by using the first voltage data and the capacitance voltage division principle and the circuit impedance conversion relationship; and a second equation in the second impedance state is established by using the second voltage data and the capacitance voltage division principle and the circuit impedance conversion relationship.

[0047] The first equation includes: ; (1) In the formula, U O 1 is the first voltage data, U i is the transmission line voltage, C1 is a high-voltage arm capacitance value, C2 is a capacitance value of a low-voltage arm capacitance, and C3 is a voltage division capacitance in the first impedance state.

[0048] The second equation includes: ; (2) In the formula, U O 2 is the second voltage data, U i is the transmission line voltage, C1 is a high-voltage arm capacitance value, C2 is a capacitance value of a low-voltage arm capacitance, and C4 is a voltage division capacitance in the second impedance state.

[0049] For example, refer to Figure 4 and Figure 5 , Figure 4 is an equivalent circuit diagram of an insulator voltage measurement device in an embodiment of the application; Figure 5 is an equivalent circuit diagram of a self-calibration system of an insulator voltage measurement device in an embodiment of the application.

[0050] For example, refer to Figure 4 , for example, Figure 4 is Figure 3The equivalent circuit diagram of the structure, that is, the equivalent circuit diagram of the smart insulator voltage measuring device, the traditional insulator is generally formed by the coupling capacitance of the high-voltage terminal and the first floating sensing electrode and the coupling capacitance of the first floating sensing electrode and the ground shielding second floating electrode, and the coupling capacitance value deviates due to the change of the installation environment and the aging of the coupling capacitance value, thereby affecting the measurement accuracy. The coupling capacitance of the first floating electrode and the ground shielding electrode is replaced by the patch capacitor C2, and the internal chamber is designed as a replaceable device, and the rear-end processing circuit is welded on the PCB board in the internal chamber. At this time, C1 and C2 form a capacitive voltage divider, and the calculation formula is: ; (3) As Figure 5 is the circuit equivalent diagram after adding impedance transformation, the parallel capacitors participate in voltage division, and it can be known that the capacitor C3 is controlled through S1, and the capacitor C4 is controlled through the switch S2. When the switch S1 is connected and the switch S2 is disconnected, the relationship formula (1) can be obtained; when the switch S2 is disconnected and the switch S1 is connected, the relationship formula (2) can be obtained.

[0051] A02, solving the target equation set to obtain the high-voltage arm capacitance value and the transmission line voltage.

[0052] Further, two unknowns are solved by two equations, and the high-voltage arm capacitance value and the transmission line voltage are obtained. Wherein, by simultaneously solving two equations, the high-voltage arm capacitance value can be obtained as follows formula (4): ; (4) In the formula, U O 1 is the first voltage data, U O 2 is the second voltage data, C1 is the high-voltage arm capacitance value, C2 is the capacitance value of the low-voltage arm capacitor, C3 is the capacitive voltage divider in the first impedance state, and C4 is the capacitive voltage divider in the second impedance state.

[0053] The transmission line voltage is as follows formula (5): ; (5) In the formula, U O 1 is the first voltage data, U O 2 is the second voltage data, U i is the transmission line voltage, C2 is the low-voltage arm capacitor, C3 is the capacitive voltage divider in the first impedance state, and C4 is the capacitive voltage divider in the second impedance state.

[0054] 103, self-calibration of the voltage dividing ratio according to the high-voltage arm capacitance value, to obtain the calibrated voltage dividing ratio of the insulator voltage measuring device.

[0055] Further, the self-calibration of the voltage dividing ratio by the high-voltage arm capacitance value ensures the accuracy of the voltage measured by the subsequent insulator voltage measuring device.

[0056] It can be understood that there is no switching of multiple impedance states or no need for switching of multiple impedance states during normal voltage measurement, and the impedance switching unit is only used for impedance conversion during self-calibration, and therefore, in order to ensure that the insulator voltage measuring device can measure accurate voltage during normal voltage measurement U i , the voltage dividing ratio needs to be calibrated to ensure accurate voltage measurement U i . The switch is in the default off state, and when self-calibration is needed, the switch state is controlled to be on or closed, and after the self-calibration is completed, the default state is restored, thereby increasing the flexibility of the method.

[0057] For example, the voltage dividing ratio is calculated by formula (6): K=(C1+C2) / C1;(6) In formula (6), K is the voltage dividing ratio, C1 is the high-voltage arm capacitance, and C2 is the low-voltage arm capacitance.

[0058] For example, the calibration of the voltage dividing ratio can be performed by the single-chip microcomputer of the impedance conversion circuit or by the subsequent conditioning circuit of the voltage measuring device. The single-chip microcomputer can also transmit C1 to the subsequent conditioning circuit for calibration of the voltage dividing ratio, and this is not limited. The low-voltage arm capacitance value and the high-voltage arm capacitance value calculated in step 102 are brought into the theoretical voltage dividing ratio calculated by formula (6), the calibrated voltage dividing ratio is the actual voltage dividing ratio after calibration, and the actual measured voltage dividing ratio is adjusted to be consistent with the theoretical voltage dividing ratio by adjusting the digital gain of the subsequent conditioning circuit, so as to achieve calibration. Specifically, if there is a deviation between the actual measured voltage dividing ratio and the theoretical voltage dividing ratio, the deviation can be corrected by adjusting the digital gain, thereby achieving calibration of the voltage dividing ratio. For example, the actual voltage dividing ratio is adjusted by the digital gain to minimize the error with the theoretical voltage dividing ratio, and the calibration of the voltage dividing ratio is completed.

[0059] For example, the voltage dividing ratio is calculated by formula (6): Figure 6 , Figure 6 is another flowchart of the self-calibration method of the insulator voltage measuring device in the embodiment of the present application, Figure 6 is a simplified flowchart of the present application, and after calibration preparation, hardware connection and parameterization design are performed, C3 and C4 are connected in sequence by switch control, and voltage data and are obtained, and finally the coupled capacitance (i.e., the high-voltage arm capacitance C1) and the voltage to be measured are calculated by solving the equation set.

[0060] The application discloses an intelligent insulator voltage sensor self-calibration system based on impedance transformation. The application solves the measurement error problem caused by the high-voltage arm capacitor value drift, has the advantages of high self-calibration precision, strong dynamic adaptability, structural integration, and the like, and is suitable for accurate measurement and real-time calibration of 10kV distribution network line voltage.

[0061] The application provides a self-calibration method of an insulator voltage measurement device, the insulator voltage measurement device being electrically connected with a power transmission line, and the method comprises the following steps: acquiring a plurality of groups of voltage data of a low-voltage arm capacitor of the insulator voltage measurement device collected under a plurality of impedance states; based on a capacitor voltage division principle and a circuit impedance transformation relationship, performing capacitor and voltage calculation by using the plurality of groups of voltage data to obtain a high-voltage arm capacitor value of the insulator voltage measurement device and a power transmission line voltage; and performing self-calibration of a voltage division ratio according to the high-voltage arm capacitor value to obtain a calibrated voltage division ratio of the insulator voltage measurement device. In the method, a plurality of groups of voltage data of the low-voltage arm capacitor of the insulator voltage measurement device under a plurality of impedance states are collected, capacitor and voltage calculation is performed by using the capacitor voltage division principle, the circuit impedance transformation relationship and the voltage data, the real-time high-voltage arm capacitor value of the insulator voltage measurement device can be obtained, the capacitor value change can be calibrated, the power transmission line voltage and the calibrated voltage division ratio can be obtained, the problem of voltage measurement error caused by unstable voltage division capacitor value is reduced, and the voltage measurement accuracy is improved.

[0062] Please refer to Figure 7 , Figure 7 The self-calibration device of the insulator voltage measurement device comprises the following components. The data acquisition module 701 is configured to acquire a plurality of groups of voltage data of a low-voltage arm capacitor of the insulator voltage measurement device collected under a plurality of impedance states. The data calculation module 702 is configured to perform capacitor and voltage calculation by using the plurality of groups of voltage data based on a capacitor voltage division principle and a circuit impedance transformation relationship to obtain a high-voltage arm capacitor value of the insulator voltage measurement device and a power transmission line voltage. The data calibration module 703 is configured to perform self-calibration of a voltage division ratio according to the high-voltage arm capacitor value to obtain a calibrated voltage division ratio of the insulator voltage measurement device.

[0063] It should be noted that,Figure 7 The content of each module in the self-calibration device shown is similar to Figure 1 The content of each step in the self-calibration method shown is similar to, to avoid repetition, please refer to Figure 1 The content of each step in the self-calibration method shown is similar to.

[0064] The application provides a self-calibration device of an insulator voltage measurement device, the insulator voltage measurement device is electrically connected with a power line, and the self-calibration device comprises a data acquisition module, a data solving module and a data calibration module. The data acquisition module is used for acquiring a plurality of groups of voltage data of a low-voltage arm capacitor of the insulator voltage measurement device collected in a plurality of impedance states. The data solving module is used for performing capacitor and voltage solving on the plurality of groups of voltage data based on a capacitor voltage dividing principle and a circuit impedance conversion relationship, so as to obtain a high-voltage arm capacitor value of the insulator voltage measurement device and a power line voltage. The data calibration module is used for performing self-calibration on a voltage dividing ratio according to the high-voltage arm capacitor value, so as to obtain a calibrated voltage dividing ratio of the insulator voltage measurement device. Through the self-calibration device, the plurality of groups of voltage data of the low-voltage arm capacitor of the insulator voltage measurement device in the plurality of impedance states are collected, the capacitor and voltage solving are performed on the voltage data based on the capacitor voltage dividing principle and the circuit impedance conversion relationship, so as to not only obtain the real-time high-voltage arm capacitor value of the insulator voltage measurement device, but also calibrate the capacitor value change, and obtain the power line voltage and the calibrated voltage dividing ratio, thereby reducing the problem of unstable voltage dividing capacitor value and further causing voltage measurement error, and improving voltage measurement accuracy.

[0065] Figure 8 An internal structure diagram of a computer device in an embodiment is shown. The computer device can be a terminal or a server. As shown in the figure, Figure 8 The computer device comprises a processor, a memory and a network interface connected through a system bus. The memory comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and can also store a computer program, which, when executed by the processor, can enable the processor to implement the above method. The internal memory can also store a computer program, which, when executed by the processor, can enable the processor to execute the above method. Those skilled in the art can understand that Figure 8 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. A specific computer device can comprise more or fewer components than those shown in the figure, or some components can be combined or have a different component arrangement.

[0066] In one embodiment, a computer device is provided, comprising a memory and a processor, the memory storing a computer program, the computer program being executed by the processor to enable the processor to execute the method as Figure 1Steps of the method shown.

[0067] In one embodiment, a computer readable storage medium is provided, storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method as Figure 1 Steps of the method shown.

[0068] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing related hardware, and the program can be stored in a non-volatile computer readable storage medium. When the program is executed, it can include the processes of the above-mentioned embodiment methods. Any reference to memory, storage, database or other medium used in each embodiment provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0069] Each technical feature of the above embodiments can be combined arbitrarily. In order to make the description simple, each technical feature of the above embodiments is not described in all possible combinations, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0070] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A self-calibration method for insulator voltage measurement devices, characterized by, The insulator voltage measuring device is electrically connected with the power transmission line, and the method comprises the following steps: a plurality of sets of voltage data of a low-voltage arm capacitor of the insulator voltage measuring device collected under a plurality of impedance states are acquired; capacitance and voltage calculation is performed on the plurality of sets of voltage data based on a capacitance voltage division principle and a circuit impedance transformation relationship, so as to obtain a high-voltage arm capacitance value and a power transmission line voltage of the insulator voltage measuring device; self-calibration of a voltage division ratio is performed according to the high-voltage arm capacitance value, so as to obtain a calibrated voltage division ratio of the insulator voltage measuring device.

2. The self-calibration method of claim 1, wherein, The capacitance and voltage calculation on the plurality of sets of voltage data based on the capacitance voltage division principle and the circuit impedance transformation relationship comprises the following steps: a target equation set is established based on the plurality of sets of voltage data based on the capacitance voltage division principle and the circuit impedance transformation relationship, unknowns of the target equation set comprising the high-voltage arm capacitance value and the power transmission line voltage; the high-voltage arm capacitance value and the power transmission line voltage are obtained by solving the target equation set.

3. The self-calibration method of claim 2, wherein, The plurality of impedance states at least comprise a first impedance state and a second impedance state, the plurality of sets of voltage data comprising first voltage data under the first impedance state and second voltage data under the second impedance state, and the target equation set is established based on the plurality of sets of voltage data based on the capacitance voltage division principle and the circuit impedance transformation relationship, which comprises the following steps: a first equation under the first impedance state is established based on the first voltage data and the capacitance voltage division principle and the circuit impedance transformation relationship; a second equation under the second impedance state is established based on the second voltage data and the capacitance voltage division principle and the circuit impedance transformation relationship.

4. The self-calibration method of claim 3, wherein, The first equation comprises the following steps: ； wherein U O 1 is the first voltage data, U i is the transmission line voltage, C1 is the high voltage arm capacitance value, C2 is the low voltage arm capacitance value, and C3 is the voltage dividing capacitance in the first impedance state.

5. The self-calibration method of claim 4, wherein, The second equation comprises the following steps: ； where U O 2 is the second voltage data, U i is the transmission line voltage, C1 is the high-voltage arm capacitance value, C2 is the low-voltage arm capacitance value, and C4 is the voltage dividing capacitance in the second impedance state.

6. The self-calibration method of claim 5, wherein, The high-voltage arm capacitance value comprises the following steps: ； where U O 1 is the first voltage data, U O 2 is the second voltage data, C1 is the high voltage arm capacitance value, C2 is the low voltage arm capacitance value, C3 is the voltage dividing capacitance in the first impedance state, and C4 is the voltage dividing capacitance in the second impedance state.

7. The self-calibration method of claim 6, wherein, The power transmission line voltage comprises the following steps: ； where U O 1 is the first voltage data, U O 2 is the second voltage data, U i is the line voltage, C2 is the low-voltage arm capacitance, C3 is the voltage dividing capacitance in the first impedance state, and C4 is the voltage dividing capacitance in the second impedance state.

8. A self-calibrating device for a voltage measuring device for insulators, characterized in that The self-calibration device comprises the following steps: a data acquisition module for acquiring a plurality of sets of voltage data of a low-voltage arm capacitor of the insulator voltage measuring device collected under a plurality of impedance states; a data calculation module for performing capacitance and voltage calculation on the plurality of sets of voltage data based on a capacitance voltage division principle and a circuit impedance transformation relationship, so as to obtain a high-voltage arm capacitance value and a power transmission line voltage of the insulator voltage measuring device; a data calibration module for performing self-calibration of a voltage division ratio according to the high-voltage arm capacitance value, so as to obtain a calibrated voltage division ratio of the insulator voltage measuring device.

9. A computer readable storage medium storing a computer program, characterized in that, The computer program is executed by the processor, so that the processor executes the steps of the method according to any one of claims 1 to 7. 10.A computer device, comprising a memory and a processor, and characterized in that, The memory stores a computer program, and the computer program is executed by the processor, so that the processor executes the steps of the method according to any one of claims 1 to 7.

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