Motor efficiency modeling towards energy optimization for two-wheel electric vehicle

Nowadays, transportation electrification represents one of the most significant changes to reduce the pollution production rate. Unfortunately, in a TWEV (two-wheel electric vehicle), particularly in the case of a motorcycle wheel hub motor, there are different constraints by using an electric driving chain. They include an autonomy reduction caused by the lack of a control system to maintain a good powertrain efficiency according to the operating parameters variation, principally in the motor. In consequence, the efficiency decreases significantly by the relationship between speed proposed by the driver and the torque required by the vehicle. Those parameters can be used in order to make an efficiency optimization based on present road/weather conditions. Regrettably, this kind of control (optimal control) requires a representative model with low computation time and easy implementation. In this paper, a convex geometrical representation of an electric motor power efficiency is proposed. This representation helps to reduce the optimization compilation time without strong accuracy losses in order to propose sophisticated co-driving profiles. Its advantages over the high mathematical complexity representation are evaluated with an electric vehicle urban speed profile and an efficiency optimization compatible with the requirements of real-time operation.