Method for testing dielectric loss and capacitance of capacitance type voltage transformer

Abstract

The invention discloses a method for testing dielectric loss and capacitance of a capacitance type voltage transformer. The method includes respectively performing positive connection test and negative connection test for the capacitance type voltage transformer by the aid of an integration method; and computing two test results by formulas to obtain the true and accurate dielectric loss and the true and accurate capacitance of the capacitance type voltage transformer. Due to influences of an electromagnetic unit of the capacitance type voltage transformer, measured dielectric loss and measured capacitance are lower than true values when the positive connection test is carried out by the aid of the integration method, and measured dielectric loss and measured capacitance are larger than the true values when the negative connection test is carried out. Accurate data more close to the true values can be obtained by means of computation by the formulas after both the positive connection test and the negative connection test are carried out.

Description

technical field [0001] The invention relates to the technical field of power equipment testing, in particular to a method for testing dielectric loss and capacitance of a capacitive voltage transformer. Background technique [0002] Capacitive voltage transformers are composed of capacitive voltage dividers and electromagnetic units. Structurally, they can be divided into split type and stacked type. The capacitive voltage divider and the electromagnetic unit of the former are connected together by external wires; the capacitive voltage divider and the electromagnetic unit of the latter have been connected together with the high-voltage terminal of the electromagnetic unit through the voltage-pumping terminal of the voltage divider inside. For the dielectric loss measurement of sub-packaged capacitor voltage transformers, both the site and the factory use conventional methods. For the stacked capacitive voltage transformer, it is divided into two types: intermediate voltage...

AI Technical Summary

Problems solved by technology

Capacitive voltage transformers with intermediate voltage-drawing terminals can be measured by conventional methods in the field as in factories; capacitive voltage transformers without intermediate voltage-drawing terminals are often measured on-site by self-excitation methods, and self-excitation methods are measured on-site. There are two problems in the test: one is that the standard capacitor CN is connected in series with C1 into the bridge, which will affect the accuracy of the test; the other is that there is a reactor connected in series with capacitor C2 in the test circuit, so the high voltage The circuit is a series resonant circuit, which may cause overvoltage and damage the capacitor voltage transformer itself

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