Optimization of MPPT step size in stand-alone solar pumping systems

In a stand-alone solar pumping system with a pump driven by an induction motor, the step size in maximum power point tracking (MPPT) methods greatly affects the dynamics and stability of the system. In this paper, we analyze some phenomena appearing in the contrastive experiments which have been carried out for about one year, and give a solution to determine the step size based on system parameters and controller capabilities. The contrastive experiments show that the system performance can be obviously improved by the optimized step size together with an adequate smoothing capacitor