Energy management of a dual-motor driven city bus based on reformed dynamic programming

Wenwei Wang ,Hong Pan,Lin Cheng

doi:10.1051/e3sconf/202123602020

Abstract

This paper proposes a reformed dynamic programming (DP) based energy management strategy for a city bus driven by dual-motor coupling propulsion system(DMCPS). An instantaneous optimal problem of DMCPS’s total energy loss is constructed to solve the torque allocation between two motors. Taking the results as extra constraints, a reformed DP architecture aimed at optimal energy consumption is established, where the state variables are the battery’s SOC and operating modes of DMCPS, with a sole decision variable of mode switching action. The optimization results show a close performance to the original method, with the calculation efficiency greatly improved and the calculation time reduced by nearly 97%. To obtain practical rules for real-time application, the mode switching schedule is extracted based on a RBF-SVM classifier, and the torque allocation is ruled by linear function. Simulation results demonstrate that the extracted rules can be executed through an on-board processor, with energy consumption reduced by 2.19% compared to the original rule-based strategy.

Highlights

Dual-motor coupling propulsion system has great advantages in realizing the comprehensive performance of battery electric city bus, with great potential for energy saving [1]
Optimization-based strategies based on dynamic programming can offer the global optimal policy, of which the real-time application is severely restricted by its large calculation workload [4,5]
Some researchers take offline global optimization results as reference to extract new control rules or recalibrate the original rules, which achieve a relative balance between both aspects [6,7]

Summary

Introduction

Dual-motor coupling propulsion system has great advantages in realizing the comprehensive performance of battery electric city bus, with great potential for energy saving [1]. Rule-based strategies have been widely utilized in practice with fast real-time calculation and good robust property [2,3]. It can hardly obtain the optimal energy consumption performance when it is only developed by empirical logic. An energy management strategy for DMCPS based on reformed dynamic programming (DP) is proposed. The rule extraction method based on the optimization results is introduced to solve the energy management problem in a typical driving cycle.

Energy management based on

Findings

Conclusion