Joint Optimization of Transmission and a Control Allocator to Minimize Power Losses in Electric Vehicles

The objective of this paper is to explore the potential of combining hardware and software design parameters in the optimization for reduced energy consumption in an electric vehicle. The vehicle used has four electric motors connected to one wheel each through a single speed transmission and a controllable coupling. The software design parameter consists of a control allocator based on a quadratic optimization program that distributes torque and wheel angle to minimize power losses in the electric motors, inverters, transmission and tires. The control allocation algorithm is then used in combination with the hardware design parameters, consisting of a controllable coupling and different transmission ratio setups between front and rear motors, in order to evaluate the joint effect on energy consumption. It was found that the energy consumption can be reduced by 8.4 % compared to equal torque distribution on all wheels