1. Electric Power Research Institute of State Grid Liaoning Electric Power Co., Ltd., Shenyang 110055, China
2. State Grid Liaoning Electric Power Supply Co., Ltd., Shenyang 110004, China
3. State Grid Zhejiang Electric Power Co., Ltd., Marketing Service Center, Hangzhou 310007, China
4. China Electric Power Research Institute Co., Ltd., Beijing 100192, China
5. School of Electrical Engineering, Shenyang University of Technology, Shenyang 110870, China