An Improved SOC Control Strategy for Electric Vehicle Hybrid Energy Storage Systems

Abstract

In this paper, we propose an optimized power distribution method for hybrid electric energy storage systems for electric vehicles (EVs). The hybrid energy storage system (HESS) uses two isolated soft-switching symmetrical half-bridge bidirectional converters connected to the battery and supercapacitor (SC) as a composite structure of the protection structure. The bidirectional converter can precisely control the charge and discharge of the SC and battery. Spiral wound SCs with mesoporous carbon electrodes are used as the energy storage units of EVs. Under the 1050 operating conditions of the EV driving cycle, the SC acts as a “peak load transfer” with a charge and discharge current of 2isc~3ibat. An improved energy allocation strategy under state of charge (SOC) control is proposed, that enables SC to charge and discharge with a peak current of approximately 4ibat. Compared with the pure battery mode, the acceleration performance of the EV is improved by approximately 50%, and the energy loss is reduced by approximately 69%. This strategy accommodates different types of load curves, and helps improve the energy utilization rate and reduce the battery aging effect.

State of Charge Estimation of Composite Energy Storage Systems with Supercapacitors and Lithium Batteries

“…e evaluation of the parameters such as the state of charge and the remaining useful life has guiding significance for the use, maintenance, and economic analysis of lithium batteries. e SOC of the compound energy storage system of electric vehicles is the basis of rational energy management [49][50][51], so accurate SOC information is of great significance to improve the dynamic performance [52,53] and range of electric vehicles [54][55][56][57][58].…”

Insights into the estimation of capacitance for carbon-based supercapacitors

“…Electronic devices are becoming popular equipment in our daily life because they reduce fossil energy utilization and don't cause any environment pollution. [1][2][3][4] Electric (electrochemical) double layer capacitors (EDLCs), as promising and environmentally friendly energy storage devices, have drawn great attention because of their fast charge-discharge capability, long cyclability, and high power density. 5,6 Although EDLCs benet from quite high power density, i.e., fast delivery of stored charge as compared to ion batteries, low energy density has yet been their limiting feature.…”

Energy Management Strategy for High-Altitude Solar Aircraft Based on Multiple Flight Phases

“…Some of these designed energy systems which had been experimentally tested and verified have made significant and pioneering contributions to the development for solar drone EMS. In addition, many scholars and researchers have studied and improved the EMS in other fields to increase the power efficiency of energy system, which include the hybrid vehicle, the air conditioning, and the light electric bus [27][28][29][30][31]. However, none of these research papers have studied the EMS for HSA in real sense based on multiple fight phases.…”