Control and performance of wind turbine generators based on permanent magnet synchronous machines feeding a diode rectifier

Permanent magnet based wind generators are one of the more promising technologies. This paper presents a simple strategy for controlling the speed and power of the wind turbine generator (WTG), connected to the grid though a diode-rectifier converter, which is less expensive but more reliable than IGBT back-to-back converter. The paper details an implementation allowing maximum power point tracking and low voltage ride through requirements. Detailed models are presented and explained. The performance of the WTG under variable wind conditions and extreme contingency, i.e. a three-phase to ground short circuit on the ac bus, is investigated. The proposed control strategy has the advantages of low parameter sensitivity and fast response speed. The paper demonstrates the WTG has excellent performances in both system normal state and contingency.