Method for testing direct-current resistance of transformer

Abstract

The invention discloses a method for testing direct-current resistance of a transformer. The method includes the steps: connecting a first series branch consisting of a first current source and a first standard resistor between an output end of a first winding and an output end of a second winding; connecting a second series branch consisting of a second current source and a second standard resistor between an output end of a second winding and an output end of a third winding; respectively measuring the voltage among the output end of the first winding, the output end of the second winding, the output end of the third winding and a neutral point and the voltage of the first standard resistor and the second standard resistor; calculating the current of the first standard resistor and the second standard resistor; and calculating the working resistance of the first winding, the second winding and the third winding. Besides, the current flowing through the second winding is equal to the sum of the current flowing through the first series branch and the current flowing through the second series branch. By the method, the working resistance of the three windings can be simultaneously measured once when the transformer is positioned at the same gear, operation is simple and easy, measuring time is greatly saved, and measuring efficiency is improved.

Description

technical field [0001] The present application relates to the technical field of electric variable measurement, in particular to a method for testing DC resistance of a transformer. Background technique [0002] The secondary winding of a multi-tap transformer is usually provided with multiple adjustable gears. The adjustable gear changes the output voltage level by changing the connection position of the secondary winding. The resistance value corresponding to each gear in the winding is directly related to the voltage of the transformer. The accuracy of the output voltage of the transformer, so the DC resistance detection of the transformer is an important inspection item in the transformer semi-finished product test, finished product factory test, installation, handover test and preventive test of the power department. Through the detection, the manufacturing defects of the transformer coil (such as Improper material selection, missing strands, disconnection, welding, oxi...

AI Technical Summary

Problems solved by technology

In addition, due to the large inductance of the transformer coil, it takes a long time to charge the coil for each individual measurement.

Therefore, a complete detection of the DC resistance of the multi-tap transformer is not only cumbersome to operate, but also takes a long time to measure and the efficiency of the measurement is low.

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