Method and system for testing saturation of current transformer

Abstract

The invention relates to a method and system for testing the saturation of a current transformer. The method comprises the following steps: reading a rated primary current, a rated secondary current, a rated secondary capacity and an accuracy limit factor; obtaining a load resistance, a winding resistance, an inflection point voltage and the maximum short-circuit current; according to the rated secondary current, rated secondary capacity, the accuracy limit factor and the winding resistance, calculating the secondary limit voltage value; according to the inflection point voltage, the maximum short-circuit current, the rated primary current, the rated secondary current, the load resistance and the winding resistance, calculating a transient factor corresponding to the maximum short-circuit current; according to the accuracy limit factor, the rated primary current and the rated secondary current, calculating a 80% rated accuracy primary limit current value of the current transformer; when the secondary limit voltage value is less than the inflection point voltage, the 80% rated accuracy primary limit current value is more than the maximum short-circuit current, and the transient factor is more than the preset factor, determining that the test on saturation of the current transformer is passed.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a method and system for checking the saturation degree of a current transformer. Background technique [0002] A current transformer usually includes a closed iron core and a winding. Its primary winding has a small number of turns and is connected in series in the current line to be measured. The above-mentioned primary winding often has all the current of the line flowing, and the secondary winding has a large number of turns. It needs to be connected in series in the measuring instrument and the protective circuit. When the current transformer is working, its secondary circuit is always closed. The impedance of the series coil of the measuring instrument and the protective circuit is very small, and the working state of the current transformer is close to a short circuit. Saturation is an important indicator of current transformers, which has an important impact on the...

AI Technical Summary

Problems solved by technology

[0004] Based on this, it is necessary to provide a method and system for checking the saturation of current transformers to solve the technical problem of low accuracy of the traditional solution for checking the saturation of current transformers.

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