A solid-state synchronous voltage source with low harmonic distortion

The power conversion requirements for a variable-speed permanent-magnet generator feeding into the network are discussed. A system using a rectifier, DC link, and grid-synchronised voltage-source inverter to process the power from a variable-speed, modular PM generator in a wind turbine is described. The inverter phase angle can be adjusted continuously to control power and turbine speed to maximum energy capture from the wind and the output voltage amplitude can be adjusted to control reactive power. Several harmonic elimination strategies are considered and the multi-pulse inverter is shown to be a cost effective solution with low current harmonics. Experimental results from a laboratory model are presented along with computer simulation results which are in good agreement