基于损耗角特性监测干式空心电抗器绝缘故障仿真研究

Simulation study on insulation fault monitoring of dry-type air-core reactor based on dielectric loss angle characteristics

空心电力电抗器在电力系统中经常出现绝缘故障,并且在故障出现前期不易被发现,导致电抗器长时间匝间短路直至烧毁。本文提出一种利用计算损耗角δ在电抗器运行及短路状态下变化的方法对电抗器绝缘故障进行监测。以一台11kV空心电力电抗器为研究对象,编程计算电抗器绝缘故障时各种电气参数并与正常工作参数做对比。仿真结果表明:发生绝缘故障时,电抗器的损耗角δ、等效阻抗、电阻等参数中变化最显著的是损耗角δ;电气参数的变化量会随着电抗器短路匝半径的变大而变大;短路匝位置越接近电抗器中部,数值变化越明显。

In power system,insulation faults often occur in air-core power reactor,and they are not easily detected in the early stage by existing methods,which leads to a long-term interturn short circuit of the reactor until it burns down.In this paper,a method to monitor insulation fault in reactor is proposed by calculating the change of loss angleδin the state of reactor operation and short circuit.A 11kV air-core power reactor is taken as the object of the research,the thin-walled solenoid model is established to calculate the inductance of reactor under working and fault conditions,and various electrical parameters in fault conditions comparing with normal working parameters are calculated.Simulation results show that loss angleδchanges fastest among loss angleδ,equivalent impedance,resistance and other parameters,in case of insulation failure.The variation of electrical parameters will increase with the radius of short circuit turn of reactor.The closer the short-circuit turn position is to the reactor center,the more obvious the numerical change is.