2Dawalibi F, Mukhedkar D. Optimum design of substation grounding in a two layer earth structure[ J]. IEEE Transactions on PAS, 1975, (2).
3Miao Hanjin, Liu Chenching, Sanghvi A P, et al. Power transformer DGA data progressing and alarming tool for on-line monitors [ J]. IEEE Transactions on Power Apparatus and Systems,2009, (2).
