Disturbance observer-based finite-time control of a photovoltaic-battery hybrid power system

Herein, the load power control of the stand-alone photovoltaic-battery hybrid power system (HPS) has been investigated. The underlying HPS consists of a boost DC-DC converter, a non-isolated bidirectional half-bridge converter, a photovoltaic (PV) panel, and a battery pack. On the PV side, a disturbance observer-based finite-time terminal sliding mode control (FTSMC) is used to regulate the DC bus to the desired voltage, in the presence of irradiation variation and load changes. On the battery side, the load power control system is constructed, based on a model predictive control (MPC) algorithm, with constraints on state-of-charge (SOC) and maximum current value of the battery to improve the battery life cycle and high reliability of the system. To highlight the benefits of the closed-loop system, the analytical proofs and numerical analysis are presented from a comparative viewpoint. The experimentally derived results, by implementation on TMS320F28335 digital signal processing (DSP), are also presented and discussed for practical justification.