Research on the Influence of Different Wiring Methods on the Conversion Results of Transformer Low-Voltage no-Load Test

Abstract

The no-load test of the transformer is an important item of the power transformer insulation preventive test, but due to the limitation of the test conditions, the field test cannot reach the rated voltage. Usually, the no-load test data measured at low voltage is converted into the no-load loss under the rated voltage. Determine the transformer condition. In this paper, the no-load test of S7-50/35 three-phase oil-immersed power transformer through five different wiring methods, the no-load loss measured under low voltage is converted to the no-load loss under rated voltage, and the experimental research and analysis are carried out. The measurement error of no-load loss under six wiring methods is discussed, and the influence of different wiring methods on the conversion result of no-load loss is discussed. The research results show that the test is carried out under the rated voltage of 22.5%~32.5%, and when the wiring method is not connected to the neutral point or only connected to the neutral point of the power supply side, the no-load loss conversion error is the smallest, and the maximum error is 3%.