A Direct Search Nelder Mead MPPT Based Induction Motor Drive for Solar PV Water Pumping System

This paper introduces a Nelder-Mead (NM) optimization approach for maximum power point tracking (MPPT) in solar photovoltaic water pumping systems (WPS). The NM method comprises four main operations, namely reflection, expansion, contraction, and shrinkage. These operations assist all particles rapidly converge toward a global maximum power point (GMPP) with negligible steady-state oscillation. A water pumping system, integrated with an induction motor drive, is operated through a scalar control method employing a three-phase voltage source inverter. To regulate the DC-link voltage, a robust control method, specifically the integral sliding mode controller (ISMC), is proposed. Furthermore, a smooth function is introduced to address the concern of chattering magnitude associated with the ISMC. The proposed system is both modeled and simulated using MATLAB followed by experimental validation. Additionally, the effectiveness of the algorithm is confirmed through comparisons with conventional methods. The proposed NM algorithm demonstrates a convergence efficiency of 99.85%, with an average tracking time of 0.23 s. The introduced control methods contribute to improvement in system performance, particularly under dynamic shading conditions.