Application of single-switch three-phase boost PFC in direct-drive wind power generation system

Direct-drive wind power generator has been receiving increasing attention due to its inherent efficiency. By eliminating the need for a gearbox between the wing turbine and generator, these systems are less expensive and also require less maintenance. And also, the direct-drive wind power topology can meet the need called low voltage ride-through. To allow the variable speed operation of the PMSG WECS, a conventional three-phase bridge rectifier (BR) with a bulky capacitor associated with voltage source current controlled inverter (VS-CSI) is used. This simple scheme introduce a high intensity low frequency current harmonic content into the PMSG and consequently increase the total lost in it, subsequently decrease the power capability of the system. In this paper, in order to decrease the current harmonic of the PMSG, a single-switch three-phase Boost PFC which interleaved running is applied to the systems. Although each path current is DCM, the complex current is CCM. It can correct the power factor of the PMSG without increase the system cost, decrease the current harmonic content of the PMSG, subsequently increase the real power ability and efficiency of system. The system has simple structure and reliability. The validity is verified by simulation.