Barrier function-based adaptive terminal sliding mode control of plug-in hybrid electric vehicle with saturated control actions

Abstract

Plugin hybrid electric vehicles in contrast to traditional hybrid electric vehicles (HEV) are getting enormous attention in the modern electric transportation market as they address the environmental issues, fuel economy crisis, and CO2 emission. Fuel cell-based PHEV with smart charging mechanism is an important application of the clean energy generation and storage system. There are two main subsystems in a PHEV: A hybrid energy storage system (HESS) and an integrated charging unit (ICU). In this study, an effective control strategy for the charger and HESS comprising three power sources: Fuel cell (FC), battery, and a superconducting magnetic energy storage (SMES) connected to the DC bus is presented. Due to the non-linearity of power conditioning circuits in ICU and HESS, designing a robust nonlinear controller is still a challenge. A barrier function-based adaptive terminal sliding mode controller is proposed to ensure the finite-time convergence of the output variable. It also maintains it in a predefined neighborhood of zero without overestimating the control gain and hence exhibits better dynamic performance in the presence of external disturbances of unknown upper bound. The asymptotic stability of the system has been ensured by using the Lyapunov stability criterion. Finally, the energy management algorithm in HESS using the state of charge of the battery and SMES as the decisive factor is incorporated to maintain the stability of the system under varying load conditions. The performance of the proposed controller has been compared with conventional nonlinear control techniques like adaptive terminal sliding mode control (ATSMC) and supertwisting sliding mode control (STSMC) by using MATLAB/Simulink. The performance of the system is further validated by using a C2000 Delfino F28379D MCU dual-core microcontroller with a hardware-in-the-loop (HIL) setup.