Maximum power point tracking of photovoltaic systems based on the sliding mode control of the module admittance

Photovoltaic (PV) grid-connected applications use an adaption stage to extract the maximum power from the PV module matching its optimal operating point with the load operation. This paper presents a sliding mode control based on the admittance of the PV module to follow a reference provided by an external maximum power point tracking (MPPT) algorithm, and at the same time, to mitigate the perturbations generated by the load. The sliding mode controller is mathematically analyzed, and a design process is proposed to ensure the desired performance in all the operation range. Finally, simulations and experimental results are used to demonstrate the efficiency of the proposed solution in the presence of both changes in the irradiance level and load perturbations.