Method for testing error influence quantity to high-voltage three-phase current transformer from high-voltage leakage current

Abstract

The invention discloses a method for testing error influence quantity to a high-voltage three-phase current transformer from high voltage leakage current, which comprises the following steps of adopting a booster to implement three-phase symmetric rated voltage on a primary terminal of the high-voltage three-phase current transformer, inputing the leakage current output by a secondary terminal of the current transformer into a transformer calibrator as differential current, and inputing one percent rated current of the secondary output of the tested current transformer which is generated by the booster and the current transformer for test into the transformer calibrator as working current, so that the transformer calibrator can directly measure the error influence quantity of the high-voltage leakage current to the high-voltage three-phase current transformer at the one percent rated current point. The phase position of the working current of the transformer calibrator is in accordance with the phase position of the voltage implemented by the primary terminal of the tested current transformer, so that the operation performance of the high-voltage three-phase current transformer under an actual operation condition is truly realized; and the accuracy of the test results and test efficiency are improved.

Description

technical field [0001] The invention relates to a new test method for the influence of high-voltage leakage current on the error of a high-voltage current transformer, which is suitable for direct testing of the influence of leakage current on the error of a current transformer in a high-voltage state, and is especially suitable for the influence of high-voltage leakage current on the error of a high-voltage three-dimensional transformer. A direct test method for the influence of phase current transformer errors. Background technique [0002] If a high voltage is applied to the primary winding of a high voltage current transformer, the high voltage will generate a capacitive current flowing from the primary winding to the secondary winding (when the secondary winding has no shielding measures), and part of this current flows through the secondary winding connected to the transformer. Secondary equipment, some flow directly to the ground terminal of the secondary winding, so ...

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Problems solved by technology

The resistance given in JJG 1021-2007 is the rated load resistance, so the resistance is too small, and the voltage at both ends is about 1mV, which is difficult to measure accurately with an AC rms voltmeter

JB / T 10432-2004 recommends 100Ω or 5Ω, so that when the leakage current is 1mA, the voltage can reach about 10mV, but it is difficult to accurately measure its size with an ordinary AC RMS voltmeter

At the same time, the above method cannot directly measure the influence of the leakage current on the actual error of the current transformer in the high-voltage three-phase combined transformer under the influence of the three-phase voltage.

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