The distributed generator (DG) with different grounding modes will affect the characteristics of singlephase earth fault current. For a low resistance grounded distribution network

the grounding mode selection of DG is rather flexible and its influence on earth fault current is particularly complicated. Based on a low resistance grounded distribution network

a singlephase earth fault analysis model of distribution network containing rotary DG is established. Earth fault point current

sequence fault current and three phase fault current are analyzed respectively when DG adopts different grounding modes. Research results show that DG with the nongrounding mode has little influence on the characteristics of earth fault current and that when DG adopts the direct grounding mode or low resistance grounding mode

fault current will obviously increase or decrease

even reaching several hundred amperes from nil

which will affect the performance of existing earth fault protection and threephase overcurrent protection. Research results can provide theoretical basis to configurations of earth fault protection and the neutral grounding mode selection of DG in low resistance grounded distribution network containing DG. This work is supported by National Natural Science Foundation of China (No. 51477184

No. 51177096) and National High Technology Research and Development Program of China (863 Program) (No. 2012AA050213).