1. Electric Power Research Institute, China Southern Power Grid, Guangzhou 510623, China
2. National Engineering Research Center of UHV Technology and New Electrical Equipment Fundamentals, Guangzhou 510623, China
3. United Laboratory of Advanced Electrical Materials and Equipment Support Technology, China Southern Power Grid, Guangzhou 510623, China
4. School of Electrical Engineering and Automation, Wuhan University, Wuhan 430072, China
5. Power Science Research Institute of Yunnan Power Grid Co., Ltd, Kunming 650217, China
6. Key Laboratory for High-efficiency Utilization of Solar Energy and Operation Control of Energy Storage System, School of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan 430068, China