New traction motor sizing strategy for an HEV/EV based on an overcurrent-tolerant prediction model

This study presents a new hybrid and electric vehicle (HEV/EV) traction motor sizing strategy, an overcurrent-tolerant prediction model is used to estimate the dynamic and thermal characteristics of a motor operating in the overcurrent region. This can be used to determine if a prospective traction motor and powertrain configuration is able to fulfil the HEV/EVs target dynamic objectives. Since the prediction model only requires minimal motor torque-speed characteristics, it can be a useful tool during the early development stages of an HEV/EV when the detailed motor parameters used in analytical models cannot be obtained. Allowing the motor to operate in the overcurrent region could downsize the traction motor used in the final HEV/EV design to one that is smaller, easier to package and likely to run in a higher efficiency region. A case study is explored where this sizing strategy is used to convert an aeroplane pushback vehicle into a series HEV and tasked with following a rigorous duty cycle. The feasibility of two HEV configurations is then analysed further. The final HEV design reduces the fuel consumption and engine emissions by up to 52% from the original internal combustion engine powered vehicle.