1. School of Electrical Engineering, Chongqing University, Chongqing, China
2. Grid Planning and Research Center, Guangdong Power Grid Corporation, CSG, Guangzhou, China
3. State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing, China
4. E.ON Energy Research Center, RWTH Aachen University, Aachen, Germany