考虑不可测负荷分支的有源配电网单相断线故障保护方法  

Single-phase Disconnection Fault Protection Method of Active Distribution Network Considering Unmeasurable Load Branch

作　　者：徐岩[1] 邹南 马天祥 段昕 XU Yan;ZOU Nan;MA Tianxiang;DUAN Xin(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University),Baoding 071003,China;State Grid Hebei Electric Power Research Institute,Shijiazhuang 050021,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),河北保定071003 [2]国网河北省电力有限公司电力科学研究院,河北石家庄050021

出　　处：《华北电力大学学报（自然科学版）》2023年第4期30-40,52,共12页Journal of North China Electric Power University：Natural Science Edition

基　　金：河北省省级科技计划资助项目(20314301D);国家电网公司科技项目(kj2020-064)。

摘　　要：有源配电网断线故障造成过电压、人身伤亡及电机损毁等事故时有发生,针对这一问题,首先分析了有源配电网断线故障后各节点负序阻抗以及断口两侧零序电压差。借鉴电流差动保护的思想,定义了负序差动阻抗,基于区内外故障时负序差动阻抗的特征差异,提出了一种基于负序差动阻抗的保护方法。该方法利用负序差动阻抗幅值作为动作量,利用其相位构造具有自适应性的制动阈值。其次,针对重载保护失效的情况,提出了将零序电压幅值差作为辅助判据。最后,分析了不可测负荷分支对上述保护判据的影响,并提出了通过比较负序电流幅值进行故障定位的方法。仿真结果表明,所述方法可以可靠定位,具有不受中性点接地方式、过渡电阻、负荷以及分布式电源影响的特点。The active distribution network disconnection fault causes accidents such as overvoltage,personal injury and death,and motor damage.To solve this problem,we first analyzed the negative sequence impedance of each node after the active distribution network disconnection fault and the zero sequence voltage difference on both sides of the fracture.With the idea of current differential protection for reference,the negative sequence differential impedance was defined.Based on the characteristic difference of the negative sequence differential impedance when the fault occurs inside and outside the area,a protection method based on the negative sequence differential impedance was proposed.This method uses the amplitude of the negative sequence differential impedance as the amount of action,and uses its phase to construct an adaptive braking threshold.Secondly,in view of the failure of the overload protection,we proposed the zero sequence voltage amplitude difference as an auxiliary criterion.Finally,we analyzed the influence of the unmeasurable load branch on the above protection criterion,and proposed a method for fault location by comparing the magnitude of the negative sequence current.The simulation results show that the method can reliably locate fault and has the characteristics of not being affected by the neutral grounding method,transition resistance,load,and distributed power sources.

关 键 词：有源配电网 断线故障 负序差动阻抗 零序电压差 不可测负荷分支 

分 类 号：TM773[电气工程—电力系统及自动化]