Fully model predictive control-based solar water pumping system with sensorless induction motor drive

Solar water pumping systems offer a practical and sustainable solution for irrigation and water supply in remote areas without access to the electrical grid. This article proposes a standalone photovoltaic (PV) water pumping system based on an induction motor (IM) drive operating under a fully model predictive control (MPC) framework. The system consists of a DC–DC boost converter for maximum power point tracking (MPPT) and a three-level neutral-point-clamped (3L-NPC) inverter supplying an IM-driven centrifugal pump. Both the DC–DC and DC–AC converters are controlled using dedicated MPC schemes to maximize energy extraction from the PV system under varying environmental conditions while ensuring high-performance motor control. In addition, a weighting-factor-free control strategy based on a normalized multi-objective decision mechanism is developed for the 3L-NPC inverter to improve control performance under varying operating conditions while reducing design complexity. A model reference adaptive system (MRAS) estimator is also employed for rotor speed and flux estimation, thereby enabling sensorless operation. Simulation results demonstrate a reduction of up to 70% in PV power settling time, a decrease in total harmonic distortion from 5.26% to 2.63%, and robust control performance under changing operating conditions.