Contribution management of lead‐acid battery, Li‐ion battery, and supercapacitor to handle different functions in EVs

Abstract

One of the most concerning issues regarding electrical vehicles (EVs) is limited driving cycle and protracted charging process. In order to improve the efficiency of current batteries, appropriate energy management systems (EMSs) could be deployed to compensate these defects. To overcome these obstacles, an EMS including a bidirectional Cuk converter and a battery storage with two types of batteries is proposed. Lithium-ion (Li-ion) and lead-acid battery types are considered as the main battery and auxiliary battery packs, respectively. Moreover, a supercapacitor is utilized to help the auxiliary battery for handling fast dynamics of the power delivery in braking and acceleration conditions. While the function of the main battery is to be charged and discharged in normal conditions, handling harsh conditions lies upon the auxiliary battery. So, the auxiliary battery can be rapidly discharged during acceleration and quickly recharged in charge stations. Furthermore, it can be used for an exchangeable battery strategy aimed at reducing congestion at charge stations. In order to plan for different scenarios, a Cuk converter is employed as a convenient interface between the batteries to manage power sharing. Operation of the system in different modes are discussed comprehensively. The performance of the proposed topology is assessed using some simulations and experiments in different conditions.