Robust sliding-mode control for maximum power point tracking of photovoltaic power systems with quantized input signal

A robust sliding-mode controller is proposed for maximum power point tracking in photovoltaic power generation system. Thanks to using hysteresis quantized inputs, the chattering phenomena, as the main weakness of the sliding mode controllers, is removed. Also, the external disturbances, model uncertainties, environmental and load variation effects are attenuated in the proposed controller scheme. The upper bound of the disturbance is assumed to be unknown and is estimated with an appropriate adaptive rule. Using the Lyapunov theory, the stability of the proposed scheme is verified and analytically proved. MATLAB simulation results confirm that the undesired effects of disturbances and chattering are simultaneously removed, as is proved in the theoretical analysis. •The efficiency of the PV cells is improved by adding a MPPT algorithm.•The hysteresis quantized input eliminates chattering and attenuates noise and disturbances.•The upper bound of the disturbance is assumed to be unknown.•The adaptive QISMC corrects error toward zero, in presence of the external disturbances.•Using the Lyapunov theory, the stability of the QISMC is verified and analytically proved.•MATLAB simulation results confirm that chattering and disturbances are effectively attenuated.