ACTIVE FILTERING APPLIED TO A LINE-COMMUTATED INVERTER FED PERMANENT MAGNET WIND GENERATOR

In this paper, the implementation of a shunt active power filter (APF) for compensating reactive and harmonic currents generated by a line-commutated inverter (LCI) in the permanent magnet synchronous generator (PMSG)
wind energy conversion systems (WECS) is presented. The system consists of wind turbine and PMSG with a sensor-less MPPT and a LCI to deliver the power to the grid. The filter consists of a three-phase current controlled voltage source inverter (CC-VSI) with a filter inductance at the ac output and a dc-bus capacitor. The CC-VSI is operated to directly control the ac grid current to be sinusoidal and in phase with the grid voltage. The switching is controlled using ramptime current control, which is based on the concept of zero average current error. The simulation results indicate that the filter is able to handle the reactive and harmonic currents, so that the grid currents are sinusoidal, in phase with the grid
voltages and symmetrical. The filter also can operate accurately regarding the wind variation.