A review of power management strategies and component sizing methods for hybrid vehicles

This paper comprehensively reviews power management strategies (PMS) and component sizing (CS) methods for hybrid vehicles with more than one energy storage system (ESS). The PMS aims to coordinate the power flow among different ESSs while meeting the drive commands and other constraints; whereas, CS is used to optimize the combination of the components to compose a cost-effective powertrain. However, these two aspects are usually coupled such that it is not reasonable to discuss them separately from a system-level design perspective. Therefore, this review briefly discusses the popular PMS, followed by a detailed CS review in different aspects, including the classic and optimization-based with their own subtypes. In addition, several case studies belonging to different optimization structures are also reviewed in detail to demonstrate the features and the main conclusions of each method. As the comparison results show that with the proper CS methods, the hybrid powertrain witness a large fuel saving compared to their conventional counterparts. Furthermore, factors or issues that affect the performance of the PMS and CS methods are discussed. Meanwhile, the future research trends in PMS and CS are elaborated. This study intends to help researchers to have an overview of the state-of-the-art in PMS and CS methods and more importantly, to provide directions for optimal powertrain and power management controller designs for cost-effective and environmental-friendly vehicles.