A quarter-car suspension model for dynamic evaluations of an in-wheel electric vehicle

Abstract

Electric vehicles (EVs) are an alternative architecture in the automotive industry that provide reduced emissions. This research has developed a switch reluctance motor (SRM) in-wheel drivetrain for an EV. SRM drivetrains are cheaper and do not use rare earth elements unlike a permanent magnet motor (PMM). Conversely, the in-wheel SRM has a drawback of an increased mass on the suspension when compared with an equivalent power output PMM drivetrain. This situation results in an increased mass at the wheels; hence, a suspension analysis is required. This paper discusses the suspension dynamics evaluated using a quarter-car simulation of an in-wheel SRM EV and compares it to the internal combustion engine (ICE) vehicle. The simulation used step loads derived design scenarios, namely (1) sprung, (2) unsprung and (3) driver’s seat. Further Bode plot analysis techniques were used to determine the ride comfort range for the developed EV.