A fast-MPPT low-complexity autonomous PV water pumping scheme for PMSM

This paper proposes an autonomous photovoltaic (PV) water pumping system for rural/remote applications. The system has been designed to minimize complexity and cost while guaranteeing fast maximum power point tracking (MPPT). This feature is essential to provide optimum utilization of solar energy, maximizing the amount of extracted water. Low complexity hardware and control ensure higher reliability and ease of installation and servicing. In the proposed scheme, the PV string is directly connected with the DC-link of a three-phase VSI, driving a PMSM pump with a standard Field Oriented Control (FOC). To achieve fast MPPT, the controller integrates a Sliding-Mode Ripple-Correlation (SMRC) MPPT algorithm, acting on the pump speed reference. The system is therefore capable of operating without the need for additional power conversion stages dedicated to MPPT. Matlab simulation results confirm the effectiveness of the proposed architecture and control.