Wind energy converter with asynchronous machines and three-phase AC controller in generator mode

Wind energy converters (WEC) with an asynchronous generator are usually con nected to the grid during start-rip time Ilia a softstarter, consisting of a thr ee-phase AC controller. In generator mode the controller is bridged a nd the wind turbine is connected directly to the grid. In this case changes of wind speed cause fluctuations of the electrical power. This paper shows , how the controller can be used as a power controller with the aim of redu cing the grid interference and life-time extension for the mechanical compo nents. In simulation and on a WEC-model 10-kW test bed it could be shown th at the power control limits the power up current to the nominal current and both power fluctuations produced by wind speed variation and tower shadow effect ar-e reduced. The harmonics were analysed and compared to the harmon ics of a six-phase generator and a twelve-pulse AC controller.