1. State Grid Dalian Electric Power Supply Company, State Grid Liaoning Electric Power Supply Co. Ltd.DalianLiaoning 116001People's Republic of China
2. Department of Electrical EngineeringNorth China Electric Power UniversityBaodingHebei 071003People's Republic of China
3. School of Electric Power, Shenyang Institute of EngineeringShenyangLiaoning 110136People's Republic of China