A self-powered capacitive voltage transformer and its error compensation method

Abstract

A self-powered capacitive voltage transformer and an error compensation method thereof include a capacitive voltage divider, a medium-voltage transformer, a voltage amplifier, a voltage transformer, an energy-sampling capacitor, a voltage-limiting circuit, and a DC / DC power supply module. A high voltage connected to a primary terminal of the capacitive voltage transformer is divided by the capacitive voltage divider into a low voltage as an input signal and input to the input end of the voltage amplifier. The voltage amplifier amplifies the low-voltage signal and inputs it to the primary winding of the medium-voltage transformer. The voltage transformer collects the voltage of the secondary winding of the medium-voltage transformer as a feedback signal and inputs it to the voltage amplifier. The energy-sampling capacitor, the voltage-limiting circuit, and the DC / DC power supply module step down and rectify the high voltage and generate positive and negative power supplies after voltage-limiting protection to supply power to the voltage amplifier. The capacitive voltage transformer proposed in the present invention realizes automatic compensation for load errors caused by a load connected in series to the secondary terminal, thereby ensuring the linearity and accuracy of the capacitive voltage transformer.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric power equipment, and more specifically, relates to a self-powered capacitive voltage transformer and an error compensation method thereof. Background Art

[0002] Capacitive voltage transformers, including capacitive voltage dividers, compensating reactors and medium-voltage transformers, have simple structural principles, no electronic devices, and no electromagnetic interference problems, and are therefore widely used in power systems.

[0003] In the prior art, "A method for improving the transient error of a capacitor voltage transformer" (CN113156360A) derives the equivalent circuit of a capacitor voltage transformer based on the physical structure of the capacitor voltage transformer; builds a transient error model of the capacitor voltage transformer; outputs a real transient error curve; connects a virtual capacitor voltage transformer transient error compensation device in series on the secondary side of the equivalent circuit of the capacitor voltage transformer to form a virtual capacitor voltage transformer transient error model; obtains the optimal parameters of the virtual capacitor voltage transformer transient error model through a parameter identification method, so that the virtual transient error curve output by the virtual capacitor voltage transformer transient error model is the closest to the real transient error curve; subtracts the virtual transient error curve from the real transient error curve to improve the transient error of the capacitor voltage transformer and improve the accuracy of voltage measurement. However, due to the nonlinearity of the compensation reactor and the nonlinearity of the medium voltage transformer, the capacitor voltage transformer often causes the voltage transformer to be 80-120% U n The error within the working voltage range has a nonlinear problem, that is, the error increases with the primary voltage U n In addition, because the secondary winding of the medium-voltage transformer needs to be connected to a meter, the meter also needs to be powered by the secondary winding. Therefore, the voltage transformer will output the corresponding supply current. The output voltage of the voltage transformer will also change with the size of the meter load, resulting in voltage transformer error. In severe cases, it may cause the full-load error and light-load error to be incompatible. Summary of the Invention

[0004] In order to address the deficiencies in the prior art, the purpose of the present invention is to provide a self-powered capacitive voltage transformer and an error compensation method thereof, so as to automatically compensate for the load error caused by the load connected in series with the secondary terminals and ensure the linearity and accuracy of the capacitive voltage transformer.

[0005] The present invention adopts the following technical solutions.

[0006] In one aspect, the present invention proposes a self-powered capacitive voltage transformer. The capacitive voltage transformer includes a capacitive voltage divider and a medium-voltage transformer. The capacitive voltage divider includes a high-voltage capacitor and a medium-voltage capacitor. One end of the high-voltage capacitor is connected to the primary terminal of the capacitive voltage transformer. The other end of the high-voltage capacitor and one end of the medium-voltage capacitor are both connected to one end of the primary winding of the medium-voltage transformer. The other end of the medium-voltage capacitor and the other end of the primary winding of the medium-voltage transformer are both grounded. The two ends of the secondary winding of the medium-voltage transformer are respectively connected to the secondary terminals of the capacitive voltage transformer, and the secondary terminals are connected in series with a load. The high voltage connected to the primary terminal of the capacitive voltage transformer is divided down to a low voltage by the capacitive voltage divider and then input into the medium-voltage transformer.

[0007] The capacitive voltage transformer also includes a voltage amplifier; the low voltage is input to the input end of the voltage amplifier as an input signal, the voltage amplifier amplifies the low voltage and inputs it to the primary winding of the medium voltage transformer. At the same time, the voltage of the secondary winding of the medium voltage transformer is converted into a feedback voltage and input into the feedback input end of the voltage amplifier. The feedback voltage compensates for the low voltage.

[0008] The signal input end of the voltage power amplifier is connected to the other end of the high-voltage capacitor and one end of the medium-voltage capacitor, and the signal output end of the voltage power amplifier is connected to one end of the primary winding of the medium-voltage transformer.

[0009] The capacitive voltage transformer also includes a voltage transformer; the voltage transformer includes a primary coil and a secondary coil;

[0010] The primary coil of the voltage transformer is connected in parallel with the secondary winding of the medium voltage transformer, one end of the secondary coil of the voltage transformer is connected to the feedback input terminal of the voltage amplifier, and the other end of the secondary coil of the voltage transformer is grounded;

[0011] The voltage transformer is used to collect the voltage of the secondary winding of the medium voltage transformer and convert the voltage of the secondary winding of the medium voltage transformer into a feedback voltage according to the voltage transformation ratio of the voltage transformer and input it to the feedback input terminal of the voltage amplifier.

[0012] The capacitive voltage transformer also includes a rectifier module; the input end of the rectifier module is connected to the primary terminal of the capacitive voltage transformer, and the output end of the rectifier module is connected to the power supply end of the voltage amplifier.

[0013] The rectifier module includes: a rectifier bridge circuit and a DC / DC power supply module;

[0014] The first AC input terminal of the rectifier bridge circuit is connected to the primary terminal of the capacitive voltage transformer, and the second AC input terminal is grounded;

[0015] The positive rectifier output terminal and the negative rectifier output terminal of the rectifier bridge circuit are respectively connected to the first input terminal and the second input terminal of the DC / DC power supply module. The first output terminal of the DC / DC power supply module outputs a positive DC voltage, and the second output terminal outputs a negative DC voltage.

[0016] The positive DC voltage and the negative DC voltage serve as the working power supply of the voltage amplifier.

[0017] The rectifier module also includes: energy-taking capacitors and DC filter capacitors;

[0018] The first AC input terminal of the rectifier bridge circuit is connected to the primary terminal of the capacitor voltage transformer through an energy-taking capacitor;

[0019] One end of the DC filter capacitor is connected to the rectifier positive output end of the rectifier bridge circuit, and the other end of the DC filter capacitor is connected to the rectifier negative output end of the rectifier bridge circuit.

[0020] The rectifier module also includes: a voltage limiting circuit;

[0021] One end of the voltage limiting circuit is connected to the rectifier positive output end of the rectifier bridge circuit, and the other end of the voltage limiting circuit is connected to the rectifier negative output end of the rectifier bridge circuit.

[0022] The ground terminal of the DC / DC power module is connected to the signal ground.

[0023] The ground terminal of the voltage amplifier is connected to the signal ground.

[0024] Another aspect of the present invention further provides a method for compensating an error in a self-powered capacitor voltage transformer, which is used to compensate for an error in the self-powered capacitor voltage transformer. The error compensation method includes:

[0025] Step 1: Collect electrical parameters of the capacitor voltage divider, the voltage transformation ratio B of the capacitor voltage transformer, and the amplification factor A1 of the voltage power amplifier;

[0026] Step 2, calculating the voltage divider ratio A2 of the capacitive voltage divider using the electrical parameters of the capacitive voltage divider;

[0027] Step 3: Adjust the voltage transformation ratio A3 of the voltage transformer so that the voltage transformation ratio A3 of the voltage transformer satisfies B=A1×A2×A3.

[0028] Furthermore, the electrical parameters of the capacitive voltage divider include: the capacitance value of the high voltage capacitor, the capacitance value of the medium voltage capacitor;

[0029] The voltage divider ratio A2 of the capacitor voltage divider satisfies the following relationship:

[0030]

[0031] Where C1 is the capacitance of the high voltage capacitor and C2 is the capacitance of the medium voltage capacitor.

[0032] The beneficial effect of the present invention is that, compared with the prior art, in the self-powered capacitive voltage transformer proposed by the present invention, a voltage amplifier is used to replace the compensating inductor in the traditional capacitive voltage transformer, and at the same time, a voltage transformer is used to collect the secondary voltage output by the capacitive voltage transformer, and the secondary voltage is converted into a voltage feedback signal and input into the voltage amplifier. The voltage amplifier compensates for the load error caused by the load on the secondary winding side of the medium-voltage transformer, so that the medium-voltage voltage signal output by the voltage amplifier is independent of the load connected to the secondary winding side, thereby significantly improving the linearity and accuracy of the self-powered capacitive voltage transformer; in addition, the secondary winding of the self-powered capacitive voltage transformer proposed by the present invention does not need to be provided with a damping device.

[0033] A voltage limiting circuit is connected to the positive and negative output terminals of the rectifier bridge circuit to prevent the primary voltage of the capacitive voltage transformer from being too high, causing the voltage on the medium voltage terminal to exceed the maximum input limit voltage of the DC / DC module after rectification, thereby damaging the DC / DC module. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is an electrical wiring diagram of a capacitor voltage transformer in the prior art;

[0035] Figure 2 This is the electrical wiring diagram for preparing a self-powered capacitive voltage transformer proposed by the present invention;

[0036] The reference numerals in the figures are described as follows:

[0037] C1-high voltage capacitor; C2-medium voltage capacitor; C3-energy extraction capacitor; C4-DC filter capacitor;

[0038] A-primary terminal of capacitor voltage transformer; 1a and 1n-secondary terminals of capacitor voltage transformer;

[0039] T1 - medium voltage transformer; T2 - voltage transformer; D - rectifier bridge circuit; Z - voltage limiting circuit; DC / DC-DC / DC power supply module; FB - feedback input of voltage amplifier; Vdd - positive DC voltage; Vss - negative DC voltage; N - ground;

[0040] A1-the amplification factor of the voltage amplifier; A2-the voltage division ratio of the capacitor voltage divider; A3-the voltage transformation ratio of the voltage transformer. DETAILED DESCRIPTION

[0041] The present application will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present application.

[0042] The electrical connection of the capacitor voltage transformer in the prior art is as follows: Figure 1 As shown, a compensation reactor is used to compensate for the voltage error caused by the secondary series load.

[0043] In one aspect, the present invention proposes a self-powered capacitive voltage transformer. Figure 2 The capacitive voltage transformer shown in the figure includes a capacitive voltage divider and a medium-voltage transformer T1; the capacitive voltage divider includes a high-voltage capacitor C1 and a medium-voltage capacitor C2, one end of the high-voltage capacitor C1 is connected to the primary terminal A of the capacitive voltage transformer, the other end of the high-voltage capacitor C1 and one end of the medium-voltage capacitor C2 are both connected to one end of the primary winding of the medium-voltage transformer T1, the other end of the medium-voltage capacitor C2 and the other end of the primary winding of the medium-voltage transformer T1 are both grounded, the two ends of the secondary winding of the medium-voltage transformer T1 are respectively connected to the secondary terminals 1a and 1n of the capacitive voltage transformer, and the secondary terminals are connected in series with a load; the high voltage U1 connected to the primary terminal A of the capacitive voltage transformer is divided into a low voltage U2 by the capacitive voltage divider and then input into the medium-voltage transformer T1.

[0044] The capacitive voltage transformer also includes a voltage power amplifier; in the self-powered capacitive voltage transformer proposed by the present invention, the voltage power amplifier is used to replace the compensating reactor in the traditional capacitive voltage transformer.

[0045] The low voltage U2 is input as an input signal to the input terminal of the voltage power amplifier. The voltage power amplifier amplifies the low voltage U2 into an output voltage U3 and inputs it to the primary winding of the medium voltage transformer T1. The voltage Uout of the secondary winding of the medium voltage transformer T1 is converted into a feedback voltage U4 and input into the feedback input terminal FB of the voltage power amplifier. The feedback voltage U4 compensates for the low voltage U2.

[0046] The signal input end of the voltage power amplifier is connected to the other end of the high voltage capacitor C1 and one end of the medium voltage capacitor C2, and the signal output end of the voltage power amplifier is connected to one end of the primary winding of the medium voltage transformer T1.

[0047] The capacitive voltage transformer also includes a voltage transformer T2; the voltage transformer T2 includes a primary coil and a secondary coil;

[0048] The primary coil of the voltage transformer T2 is connected in parallel with the secondary winding of the medium voltage transformer T1. One end of the secondary coil of the voltage transformer T1 is connected to the feedback input terminal FB of the voltage amplifier, and the other end of the secondary coil of the voltage transformer T2 is grounded.

[0049] The voltage transformer is used to collect the voltage of the secondary winding of the medium voltage transformer and convert it into a feedback voltage which is input to the feedback input terminal of the voltage power amplifier.

[0050] In this embodiment, the high-voltage capacitor C1 and the medium-voltage capacitor C2 divide the high voltage U1 into a low voltage U2 and provide it to the voltage amplifier as a signal input. The voltage amplifier amplifies the low signal U2 and outputs the output voltage U3 to the medium-voltage transformer T1. The medium-voltage transformer T1 outputs the secondary voltage Uout. The secondary voltage Uout is converted into a feedback voltage U4 according to the voltage transformation ratio of the voltage transformer through the voltage transformer T2 and input to the input feedback terminal FB of the voltage amplifier. In the self-powered capacitive voltage transformer proposed in the present invention, a voltage transformer is used to collect the secondary voltage output by the capacitive voltage transformer, and the secondary voltage is converted into a voltage feedback signal and input into the voltage amplifier.

[0051] It can be seen that in the self-powered capacitive voltage transformer proposed by the present invention, a voltage amplifier is used to replace the compensating inductor in the traditional capacitive voltage transformer, and a voltage transformer is used to collect the secondary voltage output by the capacitive voltage transformer, and the secondary voltage is converted into a voltage feedback signal and input into the voltage amplifier. The load error caused by the load on the secondary winding side of the medium-voltage transformer is compensated by the voltage amplifier, so that the medium-voltage voltage signal output by the voltage amplifier is independent of the load connected to the secondary winding side. Therefore, the linearity and accuracy of the self-powered capacitive voltage transformer are significantly improved.

[0052] The secondary winding of the self-powered capacitive voltage transformer proposed by the present invention does not need to be provided with a damping device.

[0053] The capacitive voltage transformer also includes a rectifier module; the input end of the rectifier module is connected to the primary terminal A of the capacitive voltage transformer, and the output end of the rectifier module is connected to the power supply end of the voltage amplifier.

[0054] The rectifier module includes: a rectifier bridge circuit D and a DC / DC power supply module DC / DC;

[0055] A first AC input terminal of the rectifier bridge circuit D is connected to a primary terminal A of the capacitive voltage transformer, and a second AC input terminal is grounded N.

[0056] The positive rectifier output terminal and the negative rectifier output terminal of the rectifier bridge circuit are respectively connected to the first input terminal and the second input terminal of the DC / DC power supply module. The first output terminal of the DC / DC power supply module outputs a positive DC voltage Vdd, and the second output terminal outputs a negative DC voltage Vss.

[0057] The positive DC voltage Vdd and the negative DC voltage Vss serve as the working power supply of the voltage amplifier.

[0058] The rectifier module also includes: an energy-taking capacitor C3 and a DC filter capacitor C4;

[0059] The first AC input terminal of the rectifier bridge circuit D is connected to the primary terminal A of the capacitor voltage transformer through the energy-taking capacitor C3;

[0060] One end of the DC filter capacitor C4 is connected to the rectifier positive output end of the rectifier bridge circuit D, and the other end of the DC filter capacitor C4 is connected to the rectifier negative output end of the rectifier bridge circuit D.

[0061] The rectifier module also includes: a voltage limiting circuit Z;

[0062] One end of the voltage-limiting circuit Z is connected to the positive rectifier output terminal of the rectifier bridge circuit D, and the other end is connected to the negative rectifier output terminal of the rectifier bridge circuit D. Connecting the positive and negative rectifier output terminals of the rectifier bridge circuit to a voltage-limiting circuit prevents the primary voltage of the capacitive voltage transformer from being too high, causing the voltage on the medium voltage terminal to exceed the maximum input voltage limit of the DC / DC module after rectification, thereby damaging the DC / DC module.

[0063] The ground terminal of the DC / DC power module is connected to the signal ground.

[0064] The ground terminal of the voltage amplifier is connected to the signal ground.

[0065] Another aspect of the present invention further provides a method for compensating an error in a self-powered capacitor voltage transformer, which is used to compensate for an error in the self-powered capacitor voltage transformer. The method comprises:

[0066] Step 1: Collect electrical parameters of the capacitor voltage divider, the voltage transformation ratio B of the capacitor voltage transformer, and the amplification factor A1 of the voltage power amplifier;

[0067] The voltage transformation ratio B of a capacitor voltage transformer is the ratio of the rated primary voltage U1 to the rated secondary voltage Uout. Then the voltage transformation ratio B of the capacitor voltage transformer is 100:1.

[0068] Generally, voltage amplifiers can use power supplies of ±24 to ±33V. The rated output voltage (RMS) of the voltage amplifier is generally recommended to be 14V to 35V. The output voltage can vary greatly depending on the design type of the amplifier. When the output voltage is The amplification factor of the voltage amplifier is

[0069] Step 2: Calculate the voltage divider ratio A2 of the capacitive voltage divider using the electrical parameters of the capacitive voltage divider.

[0070] The electrical parameters of the capacitive voltage divider include: the capacitance value of the high-voltage capacitor, the capacitance value of the medium-voltage capacitor;

[0071] The voltage divider ratio A2 of the capacitor voltage divider satisfies the following relationship:

[0072]

[0073] Where C1 is the capacitance of the high voltage capacitor and C2 is the capacitance of the medium voltage capacitor.

[0074] Since the medium voltage end of the capacitor voltage divider only provides a voltage input signal to the voltage amplifier, which can be a weak signal, when the capacitor voltage transformer is under rated voltage conditions, the rated output voltage of the medium voltage end of the capacitor voltage divider can be designed to be between 1 and 20V. Therefore, the rated primary voltage is The voltage divider ratio A2 of the capacitor voltage divider is 500:1~10000:1; the rated primary voltage is The voltage divider ratio A2 of the capacitor voltage divider is 1000:1 to 20000:1; the rated primary voltage is When the voltage divider ratio A2 of the capacitor voltage divider is 1750:1 to 35000:1. Optionally, the rated primary voltage is The voltage divider ratio of the capacitor voltage divider can be designed as That is 3076.9:1.

[0075] Step 3, Step 3, adjust the voltage transformation ratio A3 of the voltage transformer so that the voltage transformation ratio A3 of the voltage transformer satisfies B=A1×A2×A3.

[0076] The voltage transformation ratio A3 of the voltage transformer T2 needs to match the voltage division ratio A2 of the capacitor voltage divider and the amplification factor A1 of the voltage power amplifier, that is, B=A1×A2×A3.

[0077] therefore,

[0078] At this time, the voltage transformation ratio B of the capacitive voltage transformer is (3076.9:1)×(1:10)×(1:3.0769)=100:1. It can be seen that through the error compensation method proposed in the present invention, the load error caused by the load on the secondary winding side of the medium voltage transformer is compensated by the voltage power amplifier, so that the medium voltage signal output by the voltage power amplifier is independent of the load connected to the secondary winding side, and the error of the capacitive voltage transformer can be made zero.

[0079] The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the drawings in the specification. However, those skilled in the art should understand that the above implementation examples are only preferred implementation plans of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, and is not a limitation on the scope of protection of the present invention. On the contrary, any improvements or modifications based on the inventive spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. A self-powered capacitive voltage transformer, the capacitive voltage transformer comprising a capacitive voltage divider and a medium voltage transformer; the capacitive voltage divider comprising a high-voltage capacitor and a medium-voltage capacitor, one end of the high-voltage capacitor being connected to a primary terminal of the capacitive voltage transformer, the other end of the high-voltage capacitor and one end of the medium-voltage capacitor being connected to one end of a primary winding of the medium-voltage transformer, the other end of the medium-voltage capacitor and the other end of the primary winding of the medium-voltage transformer being grounded, the two ends of a secondary winding of the medium-voltage transformer being respectively connected to secondary terminals of the capacitive voltage transformer, the secondary terminals being connected in series with a load; the high voltage connected to the primary terminal of the capacitive voltage transformer is divided into a low voltage by the capacitive voltage divider and then input into the medium-voltage transformer; characterized in that The capacitive voltage transformer also includes a voltage power amplifier; the signal input end of the voltage power amplifier is connected to the other end of the high-voltage capacitor and one end of the medium-voltage capacitor, and the signal output end of the voltage power amplifier is connected to one end of the primary winding of the medium-voltage transformer; the capacitive voltage transformer also includes a voltage transformer; the voltage transformer includes a primary coil and a secondary coil; the primary coil of the voltage transformer is connected in parallel with the secondary winding of the medium-voltage transformer, one end of the secondary coil of the voltage transformer is connected to the feedback input end of the voltage power amplifier, and the other end of the secondary coil of the voltage transformer is grounded; The low voltage is input to the input end of the voltage power amplifier as an input signal. The voltage power amplifier amplifies the low voltage and inputs it to the primary winding of the medium voltage transformer. At the same time, the voltage transformer is used to collect the voltage of the secondary winding of the medium voltage transformer, and converts the voltage of the secondary winding of the medium voltage transformer into a feedback voltage according to the voltage transformation ratio of the voltage transformer and inputs it to the feedback input end of the voltage power amplifier. The feedback voltage compensates for the low voltage.

2. The self-powered capacitive voltage transformer according to claim 1, characterized in that: The capacitive voltage transformer further includes a rectifier module; an input end of the rectifier module is connected to a primary terminal of the capacitive voltage transformer, and an output end of the rectifier module is connected to a power supply end of a voltage amplifier.

3. The self-powered capacitive voltage transformer according to claim 2, characterized in that: The rectifier module includes: a rectifier bridge circuit and a DC / DC power supply module; The first AC input terminal of the rectifier bridge circuit is connected to the primary terminal of the capacitive voltage transformer, and the second AC input terminal is grounded; The positive rectifier output terminal and the negative rectifier output terminal of the rectifier bridge circuit are respectively connected to the first input terminal and the second input terminal of the DC / DC power supply module. The first output terminal of the DC / DC power supply module outputs a positive DC voltage, and the second output terminal outputs a negative DC voltage.

4. The self-powered capacitive voltage transformer according to claim 3, characterized in that: The positive DC voltage and the negative DC voltage serve as the working power supply of the voltage amplifier.

5. The self-powered capacitive voltage transformer according to claim 3, characterized in that: The rectifier module also includes: energy-taking capacitors and DC filter capacitors; The first AC input terminal of the rectifier bridge circuit is connected to the primary terminal of the capacitor voltage transformer through an energy-taking capacitor; One end of the DC filter capacitor is connected to the rectifier positive output end of the rectifier bridge circuit, and the other end of the DC filter capacitor is connected to the rectifier negative output end of the rectifier bridge circuit.

6. The self-powered capacitive voltage transformer according to claim 5, characterized in that: The rectifier module also includes: a voltage limiting circuit; One end of the voltage limiting circuit is connected to the rectifier positive output end of the rectifier bridge circuit, and the other end of the voltage limiting circuit is connected to the rectifier negative output end of the rectifier bridge circuit.

7. The self-powered capacitive voltage transformer according to claim 3, characterized in that: The ground terminal of the DC / DC power module is connected to the signal ground.

8. The self-powered capacitive voltage transformer according to claim 1, characterized in that: The ground terminal of the voltage amplifier is connected to the signal ground.

9. A method for compensating an error of a self-powered capacitor voltage transformer, for compensating an error of the self-powered capacitor voltage transformer according to any one of claims 1 to 8, characterized in that: The error compensation method comprises: Step 1: Collect electrical parameters of the capacitor voltage divider, the voltage transformation ratio B of the capacitor voltage transformer, and the amplification factor A1 of the voltage power amplifier; Step 2, calculating the voltage divider ratio A2 of the capacitive voltage divider using the electrical parameters of the capacitive voltage divider; Step 3: Adjust the voltage transformation ratio A3 of the voltage transformer so that the voltage transformation ratio A3 of the voltage transformer satisfies B=A1×A2×A3.

10. The error compensation method for preparing a self-powered capacitive voltage transformer according to claim 9, characterized in that: The electrical parameters of the capacitive voltage divider include: the capacitance value of the high-voltage capacitor, the capacitance value of the medium-voltage capacitor; The voltage divider ratio A2 of the capacitor voltage divider satisfies the following relationship: Where C1 is the capacitance of the high voltage capacitor and C2 is the capacitance of the medium voltage capacitor.

Images