Voltage measurement self-decoupling method based on multi-dimensional equivalent capacitance calculation

Abstract

The invention discloses a voltage measurement self-decoupling method based on multi-dimensional equivalent capacitance calculation. The method comprises the following steps: 1) determining the type of a power transmission line to be measured; 2) performing non-contact measurement on the voltage of the to-be-measured power transmission line by using a non-contact electric field sensor, and establishing a self-decoupling matrix of the to-be-measured power transmission line; 3) judging whether the sensor is symmetrically distributed based on x and z axial directions, and resolving a self-decoupling matrix; 4) performing singularity verification on the self-decoupling matrix, if the self-decoupling matrix has singularity, determining that the position of the non-contact electric field sensor is a singular measurement point, replacing the position of the non-contact electric field sensor, and returning to the step 2), and if the self-decoupling matrix has non-singularity, entering the step 5); and 5) calculating a three-phase voltage signal of the power transmission line to be measured. According to the invention, the size of the signal is actually measured through the sensor, the multi-terminal voltage signal characteristics of the power transmission line are accurate, the accuracy of the decoupling algorithm is improved, and the design difficulty caused by repeated correction is effectively reduced.

Description

technical field [0001] The invention relates to the field of electronic information, in particular to a voltage measurement self-decoupling method based on multidimensional equivalent capacitance calculation. Background technique [0002] Due to its simple structure and small size, the electric field-coupled voltage sensor has broad application prospects in the field of power frequency voltage and overvoltage measurement, and is of great significance for the monitoring of the operation status and insulation level of transmission line equipment. [0003] However, among various types of non-contact overvoltage sensors, there is still no feasible method for how to realize the decoupling of transmission line voltage. Although some sensors can be adjusted and calibrated in the experimental environment, there are strict requirements on the installation position of the sensors. Once the installation position of the sensor changes, it needs to repeat the calibration many times, whic...

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Problems solved by technology

[0006] There is also a three-phase decoupling method in the prior art, which requires three sensors to be placed under the three-phase transmission line, and then calibrated by a standard setting method, and has high requirements for the installation position of the sensors. At the same time, the solution The coupling method is only designed for horizontally distributed three-phase transmission lines, and cannot be fully applied to other types of transmission lines, such as the decoupling of inverted triangle and regular triangle transmission lines.

[0007] In general, the existing three-phase decoupling algorithm for non-contact electrical parameter measurement needs to install three electric field sensors of the same type under the three-phase transmission lines for calibration. When the sensor application scenarios (such as voltage levels) are different, The minimum safe installation distance of the sensor will change at the same time, and the circuit structure may also change. Therefore, multiple repeated measurements and calibrations are required, and multiple repeated measurements at different positions often easily lead to calibration errors, and at the same time bring huge Check workload

On the other hand, the passive calibration method is not conducive to the dynamic measurement and control of the sensor, which greatly limits the application scenarios of the sensor. For some overvoltage monitoring application scenarios that need to flexibly change the position of the sensor, the correction method is relatively difficult

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