Method for testing capacitance and dielectric loss value of 220KV coupling capacitor

Abstract

The invention relates to a method for testing capacitance and a dielectric loss value of a 220KV coupling capacitor. The method comprises the following steps of: grounding a 220kV circuit which is connected with equipment body through a grounding knife; connecting a core wire of a high voltage line to a second lap point of a tested coupling capacitor; connecting a core wire of a CX end of an instrument to a third lap point of the tested coupling capacitor; introducing a signal of a vector value I of total current which flows through an upper section of the capacitor and a lower section of the capacitor into a high voltage end of a dielectric loss tester by the core wire of the high voltage line; and measuring a vector value IC2 of current which flows through the lower section of the capacitor by the measuring end CX of the dielectric loss tester, considering the vector IC1 of the current which flows through the upper section of the capacitor as vector difference between I and IC2, comparing amplitude and phase of the current with the amplitude and the phase of the current which flows through a standard capacitor and keeping the amplitude and the phase of voltage in test unchanged to measure the capacitances of the upper section of the capacitor and the lower section of the capacitor and dielectric loss. By the method, the capacitances of the upper section of the capacitor and the lower section of the capacitor and the dielectric loss value are simultaneously measured without disassembling a high-pressure lead or replacing a measuring lead.

Description

technical field [0001] The invention relates to a method for routine maintenance of a 220KV high-voltage substation, in particular to a method for testing the capacitance and dielectric loss value of a 220KV coupling capacitor. Background technique [0002] The test method for the capacitance and dielectric loss value of the 220KV coupling capacitor in the traditional 220KV and above voltage level substation is to remove the high-voltage lead wire and replace the test lead wire. The traditional measurement principle is as follows: [0003] At present, when the traditional method measures the capacitance and dielectric loss value of the 220KV coupling capacitor, the positive connection method is used for the upper and lower nodes. The principle is as follows: figure 1 , 2 as shown, [0004] Before the test, the first lap point 1 and the third lap point 3 must be disassembled to disconnect the high-voltage lead wire from the first lap point 1, and then use a dielectric loss...

AI Technical Summary

Problems solved by technology

[0006] 1. Since the 220KV coupling capacitors are usually distributed on the edge of the substation, lift trucks cannot enter;

[0007] 2. The high-voltage leads of the coupling capacitor are high, thick, long and heavy, and the induced voltage is very high during a non-full station power outage. Therefore, it is difficult to remove the high-voltage leads for testing when the power outage is short and the personnel are limited;

[0008] 3. During the test process, the measurement wiring needs to be replaced many times, which prolongs the maintenance time and makes the test results inaccurate; coupled with the introduction of electric field and space interference, the dispersion of test data increases and the accuracy decreases, making it impossible to accurately judge the equipment insulation condition

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