Improving the performance of MPPT in a wind generation system using a wind speed estimation by Newton Raphson

Abstract

In this paper is presented an algorithm for estimating the wind speed by solving the non-linear model of a wind turbine (WT) using the Newton Raphson iterative method. The wind speed estimations obtained are used for computing the WT generator speed that maximize the extraction of wind power. This optimum generator speed is used as reference for the speed controller of a permanent magnet synchronous machine (PMSM) that works as a wind generator. The performance of the proposed algorithm is evaluated by using a WT emulator that is simulated in Matlab/Simulink. The results obtained by using a wind speed estimator as a maximum power point tracking (MPPT) algorithm are compared with the results obtained by using a perturb and observe (P&O) algorithm. Due the proposed algorithm is based on the WT mathematical model, it is sensitive to parameter uncertainties. Therefore, in order to evaluate which parameter variation will have a deeper impact in the performance of the wind speed estimator, a sensitive analysis is carried out by sweeping some parameter that will vary in a real WT. Pros and cons of the use of the proposed algorithm are discussed.