基于状态空间方程的油纸绝缘系统等效电路参数辨识

Identifying equivalent circuit parameters of oil- paper insulation system based on state- space equation

合理地辨识油纸绝缘系统等效电路的参数是绝缘老化特性分析的基础.根据回复电压测试原理,提出建立回复电压时域响应的状态空间模型,并利用控制理论中状态空间方程的求解方法结合自适应粒子群算法搜索出最优解,从而得到等效电路的未知参数值.利用国外学者所提供的一组300 MV·A油纸绝缘变压器不同充电时间下的回复电压响应曲线进行辨识,并将辨识结果所对应的回复电压曲线与测量曲线对比,二者重合度高,验证了计算模型及辨识方法的有效性.同时,分析了模型支路数不同时对辨识结果的影响,初步得出该台变压器选择6条支路辨识拟合效果最佳的结论.为油纸绝缘系统等值电路参数的辨识提供了一种新思路.

The reasonable identification of oil- paper insulation system equivalent circuit parameters is the basis of the characteristic analysis of insulation aging. According to the principle of return voltage measurement,the authors propose to establish the state space model of return voltage response in time domain,and use the method of solving state space equation theory in combination with adaptive particle swarm optimization（ PSO） algorithm to search optimal solution,so as to obtain the unknown parameters of the equivalent circuit. The authors use a set of return voltage response curves at different charging time to calculate the parameters,which obtained by measuring a 300 MV·A oil- paper insulation transformer. By contrasting the calculated RVM spectrum with the measured one,the results indicate the derived mathematical description is effective. Meanwhile,by analyzing the influence of the number of model branch to identification results,the authors predict the number of 6 is the best fit.This paper provides a new method for calculating the equivalent circuit parameters of oil- paper insulation system.