油纸绝缘等效电路参数辨识与老化评估

Equivalent circuit parameter identification and aging assessment for oil-paper insulation

基于介质时域响应的回复电压法(RVM)是通过外加电压获得电力变压器绝缘老化状态的非破坏性试验方法。采用扩展debye模型的介质响应等效电路分析油纸绝缘系统的复杂极化过程,推导出回复电压数学表达式;采用容易获得的回复电压曲线辨识等值电路参数,借助区间自适应粒子群灵活调节局部和全局搜索的能力,快速地寻找到油纸绝缘等效电路参数最优解;并通过实例仿真分析验证算法的优越性和适用性;最后分析不同绝缘状态的参数值对回复电压的影响,得到老化诊断评估方法。

The time domain dielectric response based recovery voltage method （RVM） is an ap- proach of non-destructive measurement for power transformer diagnosing insulation with applied voltage. Complex polarization process of oil-paper insulation system was analyzed by dielectric re- sponse equivalent circuit based on extended Debye model in this paper, and then the mathematical description of the equation of RVM spectrum was derived. The model parameters were calculated by the easy getting RVM spectrum. With the flexible local and global search ability of Interval A- daptive Swarm Optimization Algorithm, the optimal solution was quickly found. Simulation re- sults verified this algorithm superiority and the effectiveness in parameter calculation. Finally, the influences of parameter on the recovery voltage in different states of insulation were analyzed and an effective way to diagnose transformer＇s insulation was proposed.