Adaptive Mode Selection Strategy for Series-Parallel Hybrid Electric Vehicles Based on Variable Power Reserve

Bingfeng Zu,Haopeng Wang,Jingzheng Fan,Zhen Wang,Jianwei Zhou

doi:10.3390/en14113171

Abstract

When the series-parallel hybrid electric vehicle exits the pure electric mode, the battery provides power for the drive motor and integrated starter generator (ISG) to drive the vehicle and start the engine. If the battery discharge power is insufficient, the driving power will drop, which will inhibit the vehicle from accelerating and impair drivability. Considering that the mode selection strategy determines the timing of mode switching, this paper proposes an adaptive mode selection strategy based on variable power reserve to allow the vehicle to switch mode considering the battery power limitation. The effectiveness of this strategy is verified by simulation, and its influence on fuel consumption and battery utilization is analyzed. Compared with the mode selection strategy based on logic thresholds at the same initial battery state of charge (SOC), under the high-speed and aggressive US06 cycle, the total driving power drop is reduced by 74.2%, and the over-discharge power of the battery is fully restrained while keep almost the same fuel consumption; under the city FTP cycle, the total driving power drop is reduced 65%, and fuel consumption is reduced while maintaining SOC at a reasonable level.

Highlights

Based on the above problems, the main objective of this research is to propose an adaptive mode selection strategy based on variable power reserve, which comprehensively considers the economy and drivability
Compared with the mode selection strategy based on logic thresholds (LTB), the performance of the proposed mode selection strategy was verified
In order to solve the drivability problem caused by the battery power limitation during mode switching, this paper proposes a novel mode selection method

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. With the increasingly stringent regulations on fuel consumption and emissions in various countries, hybrid electric vehicles (HEVs) have been widely studied due to their high efficiency and low emission characteristics [1,2]. HEVs can run in different operating modes according to driving requirements and system status to achieve the required target performance [3]. In the process of switching from the pure electric mode to the hybrid mode, the battery power must meet two tasks, namely, driving the vehicle and starting the engine. When the battery power is not enough to meet the acceleration demand at the moment, the engine starting may lead to the reduction of driving power, which will deteriorate the drivability

Objectives

Results

Conclusion