Härtill 4 uppsatser

Diss. (sammanfattning) Göteborg : Chalmers tekniska högskola, 2025

This thesis addresses the energy management problem (EMP) in battery electric vehicles (BEVs), focusing on the optimization of velocity trajectory and torque distribution in vehicles equipped with multiple electric motors. Optimization-based control allocation is a widely used method for coordinating motor redundancy to enhance energy efficiency. It is based on the simplifying assumption that vehicle motion control and actuator coordination can be addressed independently. In other words, it assumes that the two subproblems constituting the EMP, i.e., finding the energy-optimal velocity trajectory and torque distribution, can be solved sequentially, as opposed to simultaneously. However, it is found in this thesis that the two subproblems are inherently coupled, as the optimal velocity trajectory depends on the efficient regions of the motors. The first part of this thesis investigates the energy consequences of solving the EMP sequentially versus jointly in a BEV with two electric motors, one per axle. Two optimization architectures are evaluated: a centralized architecture (CA) and de-centralized architecture (DCA). The second part of the thesis explores torque allocation strategies in a BEV with four identical permanent magnet synchronous motors (PMSMs) to minimize motor and tire power losses during moderate driving.