Modulation of three phase rectifier in connection With PMSG for maximum energy extraction

This paper presents a maximum power point tracking (MPPT) method which is applied on a wind turbine with permanent magnet synchronous generator (PMSG). A three-phase switched mode rectifier (SMR) is connected with the three phase output of the PMSG. The SMR employs a modulation strategy which is based on the space vector modulation (SVM) technique. Thus, the three phase input voltage is divided in six equal intervals with respect to the zero crossing of the phase voltage and only two switches are switching in each one. A duty ratio D is introduced for each switch and is able to vary by DeltaD in order to control the peak current through each phase. By controlling the three phase currents, it is possible to adjust the rotational speed of the PMSG and consequently the extracted power. The ldquohill climbingrdquo algorithm has been used for achieving operation on the maximum power point (MPP). The whole system has been designed and simulated using Matlab/Simulink and simulation results are shown for a variety of DeltaD. Finally, a short discussion about the results is given.