1. Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, Ministry of Education, Chongqing University, Chongqing 400044, China
2. School of Energy and Power Engineering, Chongqing University, Chongqing 400044, China
3. Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, U.K.
4. School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, China
5. School of Electrical Engineering, Dalian University of Technology, Dalian 116024, China
6. Department of Electrical and Electronic Engineering, The University of Manchester, Manchester M13 9PL, U.K.