Current control of battery-supercapacitors system for electric vehicles based on rule-base linear quadratic regulator

Abstract

This research aims to investigate the energy and power management of a battery-supercapacitors Hybrid Energy Storage System (HESS) for Electric vehicles (EVs). A bidirectional DC-DC converter, a battery and a set of supercapacitors were employed to construct the parallel semi-active architecture of HESS. Two strategies of Rule-Base Linear Quadratic Regulators (R-B LQRs) were proposed to manage the power flow in HESS to reduce the overall battery stress during high demand events. The supercapacitors supply the high load demand, while the battery supplies the low load demand. The HESS, EV and the proposed controllers were simulated in a MATLAB/Simulink environment. Three standard drive cycles, namely, Urban Dynamometer Driving Schedule UDDS, New York City Cycle NYCC and Japan1015 drive cycle, were implemented to validate the controller's responses. The results of the R-B LQR controllers were compared in terms number of possible drive cycles. According to the results achieved, the proposed hybridization achieves stable response of the HESS current over the drive cycles, effectively reducing the battery's size and extends its life-time.