1. School of Electrical Engineering, Tibet Agriculture and Animal Husbandry University, Linzhi 860000, China
2. Research Center of Civil, Hydraulic and Power Engineering of Tibet, Linzhi 860000, China
3. Linzhi Power Supply Company, State Grid, Linzhi 860000, China
4. College of Water Conservancy and Civil Engineering, Tibet Agriculture and Animal Husbandry University, Linzhi 860000, China