An Optimized Steepest Gradient Based Maximum Power Point Tracking for PV Control Systems

Abstract : In order to improve the photovoltaic (PV) production, the researchers are interested in developing new methods to reach the Maximum Power Point (MPP) produced by the photovoltaic field to be injected into the utility grid. This article describes a new method called the Optimized Steepest Gradient Method (OSGM), it is based on the first (gradient) and second order (hessian) derivatives of the power function in order to find the best variation of the voltage (Vpv) with the calculation of the optimal step allowing the convergence to the tension value (Vref) which ensures the MPP. The mathematical model has been developed and implemented under Matlab/Simulink environment. To analyze Maximum Power Point Tracking (MPPT) algorithm performances, time response, oscillation, overshoot and stability are taken into account. The OSGM is implemented and compared to three others algorithms (one of these algorithm is the ANFIS proposed in previous work). Performances obtained by the proposed algorithm offer faster response, less oscillations around MPP and a low energy loss. In addition, numerical computation of the gradient and the hessian of the power function allow bypassing modeling inaccuracies.