Sliding Mode Control of Onboard Energy Storage System for Railway Braking Energy Recovery

Abstract

In this study, a sliding mode controller (SMC) is constructed in order to control an onboard energy storage system ESS ensuring regenerative braking energy (RBE) saving in a railway traction system. The complete mathematical model of a supercapacitor (SC) Based energy storage system (ESS) is developed. Then, the SMC scheme is designed as to enhance both of precision and rapidity of the system. To illustrate the efficiency of the proposed controller, numerical simulations are carried out in MATLAB/SIMULINK environment. The simulation results validate the efficiency of the proposed controller, it shows that the SMC ensures a good reference tracking performance, and reduces the integral time absolute error (ITAE) by 14.39% and 21.81% compared to the classical Proportional Integral (PI) and fuzzy self-tuning PI (FSTPI) controllers, respectively. In addition, the overshoot is reduced by 18.94% and 40.28% compared to FSTPI and PI; respectively. Furthermore, a faster transient response is recorded.KeywordsSliding mode controlEnergy efficiencyEnergy storage systemSupercapacitorBraking energy recovery