1. School of Automation, Guangdong University of Technology, Guangzhou, China
2. Energy Electricity Research Center, Jinan University, Zhuhai, China
3. Department of Engineering Cybernetics, Norwegian University of Science and Technology, Trondheim, Norway
4. Department of Electric Power Engineering, Norwegian University of Science and Technology, Trondheim, Norway
5. School of Electric Power, South China University of Technology, Guangzhou, China