油纸绝缘变压器老化特征分析

目前,国内外学者对回复电压法做了大量的研究,但是还没有一个明确评估变压器油纸绝缘老化状态的方法。在理解介质极化特性的前提下,以变压器油纸绝缘极化等效电路模型为基础,仿真分析了回复电压特征量随极化等效电路参数(极化电阻、极化电容以及支路数)变化的规律。仿真结果表明,回复电压峰值的最大值、回复电压初始斜率最大值及主时间常数等可用来评估变压器绝缘状况。同时,等效电路模型的支路数也可辅助评估变压器的绝缘状况。最后对多台实际变压器进行测试分析,验证了上述特征量用于评估变压器绝缘状态是可行的。

Analysis on aging characteristics of oil-paper insulated transformer

Domestic and foreign scholars have done a lot of research on return voltage method at present , but there is not a clear method to assess the aging condition of transformer oil-paper insulation.In this paper, after under-standing the polarization characteristics of the media , using the polarization equivalent circuit model of transformer oil-paper insulation to simulate and analysis that return voltage characteristic quantity changes by changing the polarization equivalent circuit parameters （ polarization resistance , polarization capacitance and branches number ） . The simulation results show that the maximum peak voltage , maximum and initial slope of the return voltage , and the main time constant can be used to diagnose the transformer insulation condition .The branches number of the equivalent circuit model can also supplementary assess the insulation condition of transformers .Finally, testing multiple actual transformers verify that using the feature mentioned before to evaluate the transformer insulation is feasible.