Regenerative Braking Control Strategy of Vehicle With In-Wheel Motor Drive System Confronting Converter Fault
Chao Xing, Yueying Zhu, Jiaying Wang, Wei Wang, Yier Lin
Abstract
In this article, a regenerative braking control strategy with fault-tolerant capability for the electric vehicle driven by in-wheel switched reluctance motors is presented to achieve comprehensive improvement among vehicle endurance mileage, braking safety, and braking stability. First, after analyzing generation characteristic of SRM, a novel partition braking force distribution strategy is presented, combined with ideal braking force distribution and Economic Commission for Europe regulation curves. Then, a fault detection method is proposed to accurately detect the open-circuit fault of SRM drive system based on the detected phase current and position angle signals. Next, besides vehicle velocity, braking intensity, and battery state of charge, the effect of the fault on electromechanical coupling braking system (ECBS) is also considered to evaluate vehicle braking performance, further a coupling braking force control method is proposed, which can achieve open-short fault tolerance by employing mechanical braking force to replace electrical braking force. Furthermore, considering vehicle comprehensive performance, a multiobjective optimization strategy for the motor switch angles is proposed and an optimized controller is developed based on genetic algorithm. Subsequently, an improved ECBS is established and the performance of the system is analyzed and compared to the initial ECBS. The real-time capability and validity of the proposed control strategy for ECBS is validated by hardware in loop experiment.