变压器等效电路参数变化对极化谱的影响分析

基于介质响应理论的回复电压测量方法能够有效地无损诊断变压器的绝缘状态。应用回复电压测量仪RVM5461在2 000 V极化电压,0.5~1 000 s一系列充电时间,充放电时间比为2的实验条件下对1台110 kV容量31.5 MVA的变压器进行回复电压测试。利用测试得到的初试斜率、回复电压最大值、主时间常数3个特征量应用改进粒子群算法计算得到变压器油纸绝缘扩展德拜模型等效电路,并通过仿真分析了各极化支路参数的改变对回复电压极化谱的变化规律。分析结果表明,小时间常数支路、中时间常数支路和大时间常数支路分别主要影响回复电压极化谱初始、中端、末端部分。

Analysis for influence of transformer equivalent circuit parameters change on polarization spectrum

Return voltage measurement（RVM）based on dielectric response testing techniques is being investigated as potential tools for condition assessment of transformer insulation.The paper uses recovery voltage tester RVM5461 to test one 110 kV,31.5 MVA transformer under the experimental conditions of 2 000 V polarization voltage,0.5 s to 1 000 s a series of charging time and charge and discharge time ratio of 2.The paper takes the advantage of the initial slope,the maximum value of return voltage,the dominant time constant obtained from the test calculate the extended Debye model equivalent circuit of transformer oil-paper insulation by improved particle swarm algorithm,and simulates and analyses the change law of return voltage polarization spectrum based on change of the polariza tion parameter.The analysis results show that the initial part,middle part,terminal part of return voltage polarization spectrum reflects respectively the state of insulation oil,oil-paper insulation interface and solid insulation state.