A DCM three-phase high frequency semi-controlled rectifier feasible for low power WECS based on a permanent magnet generator

This paper proposes the use of a three-phase high frequency semi-controlled rectifier operating in the discontinuous conduction mode, feasible for small wind energy conversion systems based on permanent magnet generator. The main advantages of the topology are: simple gate drive circuits, since all active switches of the rectifier are connected to a common point; robustness, as short circuit through a leg is not possible; high efficiency due to reduced number of elements; simplicity since the DCM operation avoid feedback circuits and sensors as well as it allows open loop control. As a disadvantage, higher but acceptable THD of the generator currents results. The complete operation of the converter and theoretical analysis are presented. Additionally, a conventional single-phase PWM inverter is also employed in the grid connection. Experimental results on 1.6 kW prototype are presented and discussed.