中性点不同接线方式对变压器低压空载试验换算结果影响研究

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

空载试验是判断电力变压器健康状况的重要项目,由于试验条件限制,现场试验经常通过低压下测得空载试验数据换算成额定电压下的空载损耗来判断变压器状况。通过6种不同接线方式的空载试验,对低压下测得的空载损耗换算为在额定电压下的空载损耗,试验研究分析了6种接线方式下空载损耗测量误差,讨论了不同接线方式对空载损耗换算结果的影响。研究结果表明在22.5%-32.5%的额定电压下进行试验,且当接线方式为不接中性点或者只接电源侧中性点时,空载损耗换算误差最小,最大误差为3%。

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.