Abstract：The research on the generation mechanism of power cable grounding wire frequency current and the influence on protection are not clear. This paper studies the causes and characteristics of power frequency current of grounding wire, points out that the current mainly consists of the induced current which induced by the zero sequence current and the distributed current which generated by the injected current of the grounding grid. The mutual inductance circuit model of cable line and ground loop is established to describe the quantitative relation between the zero sequence current of cable and the induced current of grounding wire. Also, this paper points out that the distribution current of grounding wire depends on the topology of grounding grid and the position of current injection point, and the maximum current can be half of the injected current. Then this paper analyzes the influence of the current on the zero sequence current measurement and points out the reasons for the abnormal action of zero sequence protection and small current grounding fault selection. At last, the correctness of the above conclusion is verified by an example of zero sequence protection rejection in a wind farm.
杨远航, 石恒初, 陈剑平, 施超, 杨再鹤. 电力电缆铠装接地线工频电流产生机理及对继电保护的影响[J]. 电气技术, 2018, 19(10): 50-54.
Yang Yuanhang, Shi Hengchu, Chen Jianping, Shi Chao, Yang Zaihe. Generation mechanism of power cable grounding wire frequency current and its influence on relay. Electrical Engineering, 2018, 19(10): 50-54.
2018, Vol. 19 
