杂散阻抗对500kV自耦变压器不拆高压引线试验的影响

Influence of Stray Impedance on 500kV Autotransformer with High-Voltage Lead Wires

对于变电站中500kV主变压器,根据中华人民共和国电力工业部DL/T596-1996《电力设备预防性试验规程》的要求[1],应定期进行如下项目的绝缘预防性试验:测量绕组连同套管的绝缘电阻、吸收比或极化指数;测量绕组连同套管的泄漏电流,测量电容型套管的绝缘电阻、介质损耗因数及电容值;测量绕组的直流电阻;测量铁芯对地的绝缘电阻;绝缘油试验。后两项试验因完全不涉及高压引线问题,不在本文的讨论范围。本文仅就前四个项目中,涉及高压引线影响的部分,就不拆高压引线试验问题进行论证,试验研究结果表明,只要方法得当,不拆高压引线进行试验工作切实可行。

According to the requirements of Preventive Test Code for Electric Power Equipment-DL/T 596-1996 ,issued by[1]Ministry of Power Industry of PR.China, 500kV main transformers in substations should be preventively tested for insulation.The tests are for insulating resistance of windings with bushing,absorptance or polarization index,leakage current of windings with bushing,insulating resistance of capacitive bushing,dielectric loss factor and capacitance,de resistance of windings, insulating resistance of iron-core to earth, and insulation oil.The last two items are not discussed here due to the doing without high-voltage lead wires.This paper demonstratively presents the first four items involving the influence of high-voltage lead wires.The results show that tests with the lead wires can be feasible and performed well in correct manner.