1. South China University of Technology,China
2. School of Electric Power Engineering, South China University of Technology,Guangzhou,China,510640
3. Hong Kong Polytechnic University,Department of Electrical Engineering,Hong Kong SAR,China
4. School of Electric Power Engineering, South China University of Technology,China
5. South China University of Technology,Department of Electric Power,Guangzhou,China
6. China Electric Power Research Institute,Electricity Using and Efficiency Department,China