基于综合内积变换的小电阻接地系统高阻故障检测方法

A High Impedance Fault Detection Method of Small Resistance Grounding System Based on Integrated Inner Product Transformation

针对小电阻接地系统高阻故障时零序过电流保护灵敏度不足的问题,提出基于综合内积变换的高阻故障检测方法。分析了小电阻接地系统接地故障特征,并比较了各馈线零序电流与中性点零序电流。为了突显故障馈线与健全馈线之间的差异,提升小电阻接地系统高阻故障检测的可靠性,利用内积原理引入综合内积值为衡量指标以实现高阻故障检测。利用PSCAD建立了小电阻接地系统仿真模型并进行了故障仿真,结果表明所提出的方法能够检测高阻故障。

For insufficient sensitivity of zero sequence overcurrent protection in high impedance fault of small resistance grounding system,a high impedance fault detection method based on integrated inner product transform is proposed in this paper.The ground fault characteristics of the small resistance grounding system are analyzed and the zero sequence current of each feeder is compared with the zero sequence current of the neutral point.The inner product principle is used to distinguish the fault feeder from the healthy feeder.In order to expand the difference between the fault feeder and the healthy feeder and further improve the reliability of high impedance fault detection,the integrated inner product value is introduced as a measurement index to realize high impedance fault detection.A simulation model of small resistance grounding system is established by PSCAD and the fault simulation is carried out.The results show that the proposed method can detect high impedance fault.