1. Beijing Smartchip Microelectronics Technology Company Limited, Beijing 102200, China
2. Department of Electrical Engineering, Tsinghua University, Beijing 100084, China
3. State Key Laboratory of Power System Operation and Control, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China
4. Key Laboratory of Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China