A novel converter configuration for wind applications using PWM CSI with diode rectifier and buck converter

A novel converter configuration is proposed in this paper for mega-watt wind energy conversion system (WECS) using permanent magnet synchronous generator (PMSG). The converter consists of a diode rectifier, a buck converter and a pulse-width-modulated (PWM) current source inverter (CSI). Two DC current requirements in the system are analyzed and compared: one from the generator and diode rectifier for maximum power point tracking (MPPT), and the other from the grid and PWM CSI to obtain desired grid power factor. The theoretical analysis concludes the necessity of a buck converter for achieving all the control objectives in the full wind turbine operating range. Moreover, control scheme is developed for MPPT and grid reactive power compensation. The DC current is controlled at the minimum required level for system loss reduction. Simulation results on a 2MW WECS demonstrate the desired performance of the proposed system over a wide range.