Dr. Yeqin Wang received the B.Eng. degree in automotive engineering from the College of Engineering, China Agricultural University, Beijing, China, in 2009, the M.Eng. degree in automotive engineering from the School of Automotive Studies, Tongji University, Shanghai, China, in 2012, and the Ph.D. degree in wind science & engineering from the National Wind Institute, Texas Tech University, Lubbock, TX, USA, in 2019. He has received Outstanding Dissertation Award (2nd Place 2020) from Texas Tech University. From 2019 to 2021, he was the Director of Technology at Syndem LLC, Willowbrook, IL, USA. Since 2021, he has been an Assistant Professor at Tongji University, Shanghai, China. Since 2025, Dr. Wang has published more than 20 SCI journal papers. He is the co-author of the textbook “Principle and Control Fundamentals of Vehicle Drive Motor, 2nd edition (In Chinese)” in 2024. His current research interests include electric drive systems, power electronics control, and renewable energy.Prof. Zaimin Zhong received the B.S. and Ph.D. degrees in vehicle engineering from the Beijing Institute of Technology, Beijing, China, in 1995 and 2000, respectively. In December 2005, he became an Associate Professor, and in December 2012, he became a Professor at Tongji University, Shanghai, China. Since 2025, Prof. Zhong has published over 50 well cited research papers. He published the book entitled “Distributed Parameter Model of Electric Motors for Vehicular Applications” in 2018 and the textbook “Principle and Control Fundamentals of Vehicle Drive Motor (In Chinese)”, its 2nd edition in 2020 and 2024. His current research interests include automotive electric drive and transportation electrification.Prof. Stephan Rinderknecht studied Aerospace Engineering at the University of Stuttgart from 1984 to 1990, where he subsequently received his doctorate degree in 1994. After working as a post-doc at the Institute for Statics and Dynamics of Aerospace Constructions (ISD) at the University of Stuttgart, he moved to industry in 1995. Until 2008 he worked as a development engineer and last as Vice President Research and Development at GETRAG Getriebe- und Zahnradfabrik Hermann Hagenmeyer GmbH & Cie KG in Ludwigsburg, Untergruppenbach and St. Georgen. Since 2009 he has been a professor for Mechatronic Systems in Mechanical Engineering at the TU Darmstadt. Prof. Rinderknecht is active in various program committees (e.g. CTI Symposium Automotive Drivetrains, VDI Dritev, VDI Mechatronics, SIRM – Vibrations in Rotating Machinary), as a member of the Mechatronics Technical Committee of the VDI/VDE Society for Measurement and Automation Technology (GMA) and as an editorial board member of the open access journal “vehicles” at MDPI. His current research is on architectures for hybrid and electric drives and the system development of mechatronic transmissions, the design of flywheel energy storages and control of multimodal smart grids as well as sectorial system coupling and integration.

• Chapter 1 Introduction.- Chapter 2 Magnetic Field and Magnetic Circuit.- Chapter 3 Electromechanical Energy Conversion and Electromagnetic Torque Generation.

Dr. Yeqin Wang received the B.Eng. degree in automotive engineering from the College of Engineering, China Agricultural University, Beijing, China, in 2009, the M.Eng. degree in automotive engineering from the School of Automotive Studies, Tongji University, Shanghai, China, in 2012, and the Ph.D. degree in wind science & engineering from the National Wind Institute, Texas Tech University, Lubbock, TX, USA, in 2019. He has received Outstanding Dissertation Award (2nd Place 2020) from Texas Tech University. From 2019 to 2021, he was the Director of Technology at Syndem LLC, Willowbrook, IL, USA. Since 2021, he has been an Assistant Professor at Tongji University, Shanghai, China. Since 2025, Dr. Wang has published more than 20 SCI journal papers. He is the co-author of the textbook “Principle and Control Fundamentals of Vehicle Drive Motor, 2nd edition (In Chinese)” in 2024. His current research interests include electric drive systems, power electronics control, and renewable energy.Prof. Zaimin Zhong received the B.S. and Ph.D. degrees in vehicle engineering from the Beijing Institute of Technology, Beijing, China, in 1995 and 2000, respectively. In December 2005, he became an Associate Professor, and in December 2012, he became a Professor at Tongji University, Shanghai, China. Since 2025, Prof. Zhong has published over 50 well cited research papers. He published the book entitled “Distributed Parameter Model of Electric Motors for Vehicular Applications” in 2018 and the textbook “Principle and Control Fundamentals of Vehicle Drive Motor (In Chinese)”, its 2nd edition in 2020 and 2024. His current research interests include automotive electric drive and transportation electrification.Prof. Stephan Rinderknecht studied Aerospace Engineering at the University of Stuttgart from 1984 to 1990, where he subsequently received his doctorate degree in 1994. After working as a post-doc at the Institute for Statics and Dynamics of Aerospace Constructions (ISD) at the University of Stuttgart, he moved to industry in 1995. Until 2008 he worked as a development engineer and last as Vice President Research and Development at GETRAG Getriebe- und Zahnradfabrik Hermann Hagenmeyer GmbH & Cie KG in Ludwigsburg, Untergruppenbach and St. Georgen. Since 2009 he has been a professor for Mechatronic Systems in Mechanical Engineering at the TU Darmstadt. Prof. Rinderknecht is active in various program committees (e.g. CTI Symposium Automotive Drivetrains, VDI Dritev, VDI Mechatronics, SIRM – Vibrations in Rotating Machinary), as a member of the Mechatronics Technical Committee of the VDI/VDE Society for Measurement and Automation Technology (GMA) and as an editorial board member of the open access journal “vehicles” at MDPI. His current research is on architectures for hybrid and electric drives and the system development of mechatronic transmissions, the design of flywheel energy storages and control of multimodal smart grids as well as sectorial system coupling and integration.

• Chapter 1 Introduction.- Chapter 2 Magnetic Field and Magnetic Circuit.- Chapter 3 Electromechanical Energy Conversion and Electromagnetic Torque Generation.

Dr. Yeqin Wang received the B.Eng. degree in automotive engineering from the College of Engineering, China Agricultural University, Beijing, China, in 2009, the M.Eng. degree in automotive engineering from the School of Automotive Studies, Tongji University, Shanghai, China, in 2012, and the Ph.D. degree in wind science & engineering from the National Wind Institute, Texas Tech University, Lubbock, TX, USA, in 2019. He has received Outstanding Dissertation Award (2nd Place 2020) from Texas Tech University. From 2019 to 2021, he was the Director of Technology at Syndem LLC, Willowbrook, IL, USA. Since 2021, he has been an Assistant Professor at Tongji University, Shanghai, China. Since 2025, Dr. Wang has published more than 20 SCI journal papers. He is the co-author of the textbook “Principle and Control Fundamentals of Vehicle Drive Motor, 2nd edition (In Chinese)” in 2024. His current research interests include electric drive systems, power electronics control, and renewable energy.Prof. Zaimin Zhong received the B.S. and Ph.D. degrees in vehicle engineering from the Beijing Institute of Technology, Beijing, China, in 1995 and 2000, respectively. In December 2005, he became an Associate Professor, and in December 2012, he became a Professor at Tongji University, Shanghai, China. Since 2025, Prof. Zhong has published over 50 well cited research papers. He published the book entitled “Distributed Parameter Model of Electric Motors for Vehicular Applications” in 2018 and the textbook “Principle and Control Fundamentals of Vehicle Drive Motor (In Chinese)”, its 2nd edition in 2020 and 2024. His current research interests include automotive electric drive and transportation electrification.Prof. Stephan Rinderknecht studied Aerospace Engineering at the University of Stuttgart from 1984 to 1990, where he subsequently received his doctorate degree in 1994. After working as a post-doc at the Institute for Statics and Dynamics of Aerospace Constructions (ISD) at the University of Stuttgart, he moved to industry in 1995. Until 2008 he worked as a development engineer and last as Vice President Research and Development at GETRAG Getriebe- und Zahnradfabrik Hermann Hagenmeyer GmbH & Cie KG in Ludwigsburg, Untergruppenbach and St. Georgen. Since 2009 he has been a professor for Mechatronic Systems in Mechanical Engineering at the TU Darmstadt. Prof. Rinderknecht is active in various program committees (e.g. CTI Symposium Automotive Drivetrains, VDI Dritev, VDI Mechatronics, SIRM – Vibrations in Rotating Machinary), as a member of the Mechatronics Technical Committee of the VDI/VDE Society for Measurement and Automation Technology (GMA) and as an editorial board member of the open access journal “vehicles” at MDPI. His current research is on architectures for hybrid and electric drives and the system development of mechatronic transmissions, the design of flywheel energy storages and control of multimodal smart grids as well as sectorial system coupling and integration.

• Chapter 1 Introduction.- Chapter 2 Magnetic Field and Magnetic Circuit.- Chapter 3 Electromechanical Energy Conversion and Electromagnetic Torque Generation.