[1] Architectural Design and Research Institute of Guangdong Province, Guangzhou 510010, China
[2] College of Electrical Engineering, Chongqing University, Chongqing 400044, China
[3] Guangzhou Institute of Measuring and Testing Technology, Guangzhou 510030, China
[4] Mianyang Electric Power Company, Mianyang 621000, China
[5] Southwest Electric Power Design Institute, Chengdu 610021, China