Conditioned-based robust nonlinear control of plug-in hybrid electric vehicle with saturated control actions

Abstract

Plug-in hybrid electric vehicles (PHEVs) are considered to be a better choice than conventional hybrid electric vehicles due to environmental concerns. There are two main subsystems in the PHEVs power system namely: integrated charging unit (ICU) and hybrid energy storage system (HESS). In this work three energy sources fuel cell (FC), battery and ultra-capacitor (UC) are considered. Keeping in view of different challenging aspects like actuator limits and nonlinear nature of power conditioning circuits in ICU and HESS, design of robust nonlinear controller is still a challenge. Conventional Supertwisting Algorithm (STA) based controller exhibits wind-up effects when control signal is saturated which deteriorates the dynamic response of the controller. In order to resolve this issue, conditioning technique is used to propose conditioned Supertwisting algorithm (CSTA) based controller which mitigates the wind-up phenomenon when the control signal is saturated and exhibits better dynamic performance in the presence of external disturbances. Moreover, energy management algorithm in HESS is also presented in which State of Charge (SoC) of the battery and UC is taken as a decisive factor for the execution of rule-based strategy. Asymptotic stability of the system is proved using Lyapunov stability criterion. Simulations are performed in Matlab/Simulink ODE 45 environment which show the comparison of the proposed controller with conventional STA-based controller. The results show better performance of proposed controller when the control signals are saturated but at the same time conventional STA does not exhibit good response due to integrator wind-up. For the real-time control of PHEV, hardware in loop (HIL)-based experimental verification is also done.