Abstract:
Plugin hybrid electric vehicles (PHEVs) are getting the attention of electric
transportation market and the end-users. They comprise of smart charging mechanism and a hybrid energy storage system (HESS). In this study,
a topology for HESS based on battery/ultracapacitor (UC), coupled with
two bi-directional DC-DC buck-boost converters has been considered. For
controlled integrated charging and smooth execution of energy management
algorithm, a unidirectional DC-DC converter has been used. The mathematical model of the complete HESS with integrated charging unit for PHEV
has been designed. A nonlinear controller termed as adaptive terminal sliding mode control (ATSMC) along with adaptive law has been proposed. The
controller parameters have been tuned using genetic algorithm. Also an algorithm of high level control has been presented to switch between static
and dynamic behaviors of the PHEV. The objective of the proposed control
strategy is to adapt the unknown parameters of the system, deliver power
for load well in time, output DC bus voltage regulation and smooth tracking
of reference currents for the battery and UC with varying demands of the
vehicle. The asymptotic stability of the system has been ensured by using
Lyapunov stability theory. Finally, the energy management algorithm using the state of charge (SoC) as decisive factor is incorporated to maintain
the stability of the system under varying load conditions. The performance
of proposed controller has been compared with conventional sliding mode
controller (SMC) and finite time synergetic controller (FTSC) using MATLAB/Simulink. The performance of the system is further verified by testing
it on real-time hardware-in-loop setup.
