Research on the influence of different neutral connection modes on the conversion results of transformer low-voltage no-load test

No-load test is an important item to judge the health status of power transformers. Due to the limitation of test conditions, field tests often judge the condition of transformers by converting the no-load test data measured at low voltage into the no-load loss at rated voltage. In this paper, the no-load loss measured at low voltage is converted to the no-load loss measured at rated voltage through the no-load test of six different connection modes,and the measurement error of no-load loss under six different connection modes is analyzed, and the influence of different connection modes on the no-load loss conversion results is discussed. The results show that the conversion error of no-load loss is the minimum, and the maximum error is 3% when the rated voltage is 22.5%~32.5%. The wiring mode is not connected to the neutral point or only connected to the neutral point on the power side.