Ronghai Qu, Fellow IEEE, Fellow of China Electrotechnical Society, received his B.E. and M.S. degrees from Tsinghua University, Beijing, China, in 1993 and 1996, respectively, and the Ph.D. degree in electrical engineering from University of Wisconsin-Madison in 2002. He had been with the General Electric (GE) Global Research Center, Niskayuna, NY as a Senior Electrical Engineer with the Electrical Machines and Drives Laboratory from 2003 to 2010. He was the recipient of 11 GE GRC awards including EPST Technical Achievement Award, Outstanding Teamwork and Management Award. In 2010 he joined Huazhong University of Science & Technology, Wuhan, China. He is currently director of State and Province Joint Engineering Research Center of Novel Electrical Machines, and director of Center for Advanced Electrical Machines and Drives (CAEMD). From 2012 to 2016, he served as deputy dean of school of Electrical & Electronic Engineering. He is currently a member of ICEM NPO AdCom and the chair of IEEE Industry Application Society (IAS) Wuhan Chapter. His research interests include Design and Drive of Electrical Machines. He has published over 400 technical papers including 14 IEEE award papers and holds over 170 patents. Dr. Qu is also a winner of several other awards including 2020 Science and Technology Invention Award (1st prize) from China Electrotechnical Society, the 7th Nagamori Awards from Nagamori Foundation, Japan, 2021, and 2 gold Medals from the 47th Exhibition of Inventions of Geneva, 2019, the 12th Innovation and Entrepreneurial Figure Award, China Association of Inventions,2022.

Hair-pin Winding Permanent Magnet Machines

The rectangular wire winding AC electrical machine has drawn extensive attention due to their high slot fill factor, good heat dissipation, strong rigidity and short end-windings, which have been employed for some traction application so as to enhance torque density, improve efficiency, decrease vibration and weaken noise, etc. In this tutorial, based on the complex process craft and the electromagnetic performance, a comprehensive and systematical overview on the rectangular wire windings AC electrical machine is introduced. According to the process craft, the different type of the rectangular wire windings, the different inserting direction of the rectangular wire windings and the insulation structure have been compared and analyzed. Furthermore, the detailed rectangular wire windings connection is researched and the general design guideline has been concluded. Especially, the performance of rectangular wire windings AC machine has been presented, with emphasis on the measure of improving the bigger AC copper losses at the high speed condition due to the distinguished proximity and skin effects. Finally, the future trend of the rectangular wire windings AC electrical machine is prospected.