Power conversion interface for small-capacity wind power generation system
Power conversion interface for small-capacity wind power generation system based on permanent-magnet synchronous generator (PMSG) is proposed in this paper. The proposed power conversion interface will convert the wind power generated from the three-phase PMSG to a high quality power to inject into the single-phase utility. This power conversion interface comprises of a power converter and a zero-sequence transformer set. The power converter is controlled to generate a set of positive-sequence currents to absorb a real power from the three-phase PMSG and a set of zero-sequence currents to pass through the zero-sequence transformer set to the single-phase utility. A feed-forward control is used to control the proposed power conversion interface so as to simplify the control circuit. A simplified maximum power point tracking method is also proposed and incorporated in the control circuit of the power conversion interface to extract the maximum power of the PMSG-based wind power generation system. Hence, the proposed power conversion interface has the advantages of simplifying both the power circuit and the control circuit. A prototype is developed to demonstrate the performance of the proposed power conversion interface. The experimental results show that the proposed power conversion interface can achieve the expected performance.