基于双端剩余电流突变量的漏电保护方法

Leakage Protection Method Based on Double-terminal Residual Current Mutations

为克服现有单端量漏电保护方法的不足,并着眼于配电物联网技术带来的便利条件,在分析0.4 kV低压配电线路单相漏电故障特征的基础上,提出一种基于双端剩余电流突变量的漏电保护方法,利用被保护线路双端剩余电流突变量的幅值构造保护判据,在双端判据均符合各自整定阈值要求时保护动作。给出了方法实现流程和适应性。该方法综合利用线路双端剩余电流信息,可基于配电物联网平台实现;可排除正常运行时线路不平衡泄漏电流等因素的影响,减少保护误动,提高保护投用率;不需多级保护延时配合,动作速度快;整定值低,灵敏度高。通过MATLAB仿真和试验录波验证了方法的有效性。

In order to overcome the defects of existing singleterminal leakage protection methods,and focus on the conveniences brought by the power distribution internet of things technology,based on analyses of single-phase leakage faults features in 0.4 kV LV(low voltage)distribution lines,this paper proposes a leakage protection method based on doubleterminal residual current mutations,using the amplitudes of the double-terminal residual current mutations of protected line to construct the protection criteria.The protection acts when double-terminal criteria both meet the requirements of respective setting thresholds.The realization process and adaptability of the method are given.This method comprehensively utilizes the two terminal residual current information of protected section,and can be realized based on the distribution internet of things platform.It can effectively eliminate the influences of unbalanced leakage current of line during normal operation and other factors,reduce maloperation and improve the utilization rates of protection.It doesn’t need multi-level protection delay coordination and has fast action speed.It has low setting thresholds and high sensitivity.The effectiveness of the method is verified by MATLAB simulation and test recording.