1. Key Laboratory of Power System Optimization and Energy Saving Technology, Guangxi University, Nanning 530004, China
2. Department of Electrical Engineering, School of Automation, Guangdong University of Technology, Guangzhou 510006, China
3. Electric Power Research Institute, Guangxi Power Grid Corporation, Nanning 530023, China
4. School of Electric Power, South China University of Technology, Guangzhou 510640, China
5. Guangxi Minhai Energy Co., Ltd., Nanning 530012, China
6. Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China