Design and analysis of a novel asymmetric PM-assisted synchronous reluctance motor used for electric vehicles

This paper proposes a novel asymmetric permanent magnet assisted synchronous reluctance motor (APMA-SynRM) used for electric vehicles (EVs), which adopts the magnetic isolation flux barrier to enhance the effect of magnetic field shifting. Firstly, the magnetic field shifting principle and magnetic circuit model of APMA-SynRM are analysed. Then, a new design method of APMA-SynRM that makes the reluctance torque and permanent magnet (PM) torque reach the peak value at same current angle is proposed. According to the design method's analysis, the condition that the structural and magnetic property parameters of APMA-SynRM should meet is obtained, which provides significant reference for the APMA-SynRM's design. After that, an APMA-SynRM scheme is designed to verify the design method's accuracy and effectiveness. Finally, the electromagnetic and mechanical strength performances of APMA-SynRM and corresponding permanent magnet assisted synchronous reluctance motor (PMA-SynRM) are studied, which demonstrates the feasibility of APMA-SynRM's application in EVs.