Performance Comparison of Permanent Magnet and Electrically Excited Motors for Electric Vehicles

Abstract

The objective of this paper is to compare and analyze two types of electric motors, an electrically excited synchronous motor (EESM) and an interior permanent magnet (IPM) motor for an electric vehicle (EV) application. In order to achieve the objective, a comparative analysis of the EESM and IPM motors is presented via the analytic model and finite element method to examine and simulate the torque and power performances as well as their efficiency maps of both motors based on a Volkswagen ID.3 2020 reference model. The analysis takes into account the same machine size and power inverter for both motors. The examination indicates that the EESM achieved better torque and power but lower efficiency, especially at high speeds. The EESM requires flux weakening for a wider constant power range. The EESM can be a low-cost alternative given its adjustable excitation. The EESM has achieved a wider speed range but lower peak efficiency than the IPM. Findings inform optimal propulsion system design for EVs. This research provides valuable insights for automakers seeking to optimize drivetrain performance by selecting suitable electric motor options. The findings contribute to the advancement of next-generation propulsion systems for electric mobility.