Landscaping and Review of Traction Motors for Electric Vehicle Applications

With increasing penetration of electric vehicles, electric motor technologies have also seen rapid evolution. This paper reviews and provides a landscape of several topologies of traction motors employed in electrical vehicle traction applications. An emphasis has been made to showcase trends in volumetric power density and gravimetric power density of traction motors since they directly affect end product weight, packaging, and efficiency. A study and classification of motor topologies based on permanent magnet use, the location of the permanent magnets inside the motor, magnetic and reluctance components of torque, and design trends in rotor and stator have been discussed. Several key Original Equipment Manufacturers (OEM) products have been used in this analysis and thus, the paper provides a useful reference for understanding the product evolution and forecasting future trends.