T-S fuzzy control for MPPT of photovoltaic pumping system

This paper presents a robust fuzzy control scheme for maximum power tracking of a photovoltaic (PV) pumping system dedicated to domestic use. This system is composed of a photovoltaic generator (PVG) supplying via a DC-DC boost converter, a DC motor coupled to a centrifugal pump. A knowledge dynamic model of the pumping system is firstly developed leading to a Takagi Sugeno (TS) representation by a simple convex polytopic transformation. This approach allows to reproduce the dynamic behavior of the system with accuracy over a wide operating range. Then, a robust T-S fuzzy MPPT controller is designed to track the reference speed and achieve an optimal operation of the photovoltaic pumping system. The proposed controller generates the optimal duty cycle to match the motor-pump impedance with the PV generator via a DC-DC converter, and thus, maximizes the quantity of water pumped daily. Finally, simulation results which take into account all changes in climatic conditions are presented for both transient and steady state operation.