Optimal Brake Allocation in Electric Vehicles for Maximizing Energy Harvesting During Braking

Abstract

This article proposes a novel approach to efficiently distribute braking force of an electric vehicle (EV) between friction and regenerative braking with an ultimate goal of maximizing harvested energy during braking. The regenerative braking performance of an EV depends on various factors influenced by the driver behavior and driving conditions, which are challenging to measure or predict in real-time. In the proposed method, the performance map of the traction motor (TM) and its controller is used to define a boundary in which blending of regenerative and friction braking is performed with the goal of maximizing recaptured energy through the regenerative braking process. The performance, effectiveness, and robustness of the proposed strategy are validated through a hardware-in-the-loop (HIL) experimental testbed for a predetermined drive cycle of Urban Dynamometer Driving Schedule (UDDS). It is shown that using the proposed method, the amount of recaptured energy through the regenerative braking process can significantly increase compared to constant or variable boundary methods using a weight factor for brake distribution.