MPPT Control of PMSG Based Small-Scale Wind Energy Conversion System Connected to DC-Bus

Abstract

While the use of renewable energy systems in electric power generation is increasing more and more, wind energy conversion systems (WECS) receive considerable attention among these. Thanks to the ability of power generation in all wind speed range by controlling the rotor speed, Variable Speed WECSs are more preferred than fixed speed WECSs. When considering small-scale applications in variable speed WECS, Permanent Magnet Synchronous Generator (PMSG) based WECS structures are focus of the interest due to their advantages such as high efficiency and low maintenance costs. The generator must be operated at an optimum speed to obtain maximum power from the WECS. Moreover, different Maximum Power Point Tracking (MPPT) methods can be used to control and determine optimal operating speed. In this paper, WECS configuration consists of PMSG, uncontrolled rectifier, DC link capacitor, DC-DC boost converter and DC-Bus. Capturing the maximum power from WECS and supplying the DC-Bus is performed via tip speed ratio and PI control (TSR-PI) based MPPT method. Moreover, two wind speed profiles having constant and instant changes are created to test the performance of the proposed method. For comparison purposes, perturbation & observation (P&O) based MPPT method is also carried out in here. According to obtained results from this study performed in Matlab/Simulink environment, it is verified that TSR-PI based MPPT method ensures higher power and efficiency for these wind speed profiles by means of a more successful generator speed tracking.