| PhD Seminar

Name of the Speaker: Ms. Veena P (EE19D208)
Guide: Dr. Kamalesh Hatua
Venue: ESB-244 (Seminar Hall)
Date/Time: 18th Aug 2025(Friday), 3 PM
Title: Design of Multipole Permanent Magnet Assisted Synchronous Reluctance Machine for Electric Vehicle Application

Abstract :

Permanent Magnet Synchronous Motors (PMSMs), Synchronous Reluctance Machines (SynRMs), and Permanent Magnet-assisted Synchronous Reluctance Machines (PMaSynRMs) are widely used classes of traction motors in EVs. PMSMs offer high efficiency and power density but are costly due to rare-earth magnets. SynRMs are cheaper and simpler but have lower torque density and power factor. PMaSynRMs combine both, using minimal magnets to enhance SynRM performance.

For applications demanding a very high Constant Power Speed Range (CPSR), the motor must operate extensively in the Field-Weakening (FW) region, where efficiency significantly drops. An alternative to deep FW operation is to either increase the DC bus voltage or use winding changeover techniques — both of which add to the drive's weight and cost. In this seminar, a multipole motor for EVs that demands a wide CPSR, is discussed. The machine features two distinct pole sets and operates as a PMaSynRM. The rotor of the machine is a hybrid of SynRM and PMSM. The stator houses two sets of 3-phase windings, corresponding to each pole. Both components are operated till an intermediate speed, after which, the excitation of SynRM is removed without the use of any switches, since the back-EMF in SynRM due to PM is negligible. Only the PM part is operated till maximum speed, without entering FW. Hence, the proposed machine can be used to obtain extended speed with improved efficiency due to the absence of extra FW current. In this seminar, the concepts of this machine will be discussed along with its operation and experimental results.