4Hanninen E, Lehtonen M. Characteristics of earth faults in electrical distribution networks with high impedance earthing [ J ]. Electric Power System Research, 1998 (44): 155-161.
5Matti Lehtonen. Transient analysis for ground fault distance estimation in electrical distribution networks [ M ]. Technical Research Centre of Finland Espoo, 1992.
6Scott F E. New ground fault protection system minimizes electrical shock hazards [ M ]. Coal Mining &Processing, 1981.