MEGAWATT DIRECT DRIVE TYPE SQUIRREL-CAGE ASYNCHRONOUS GENERATOR AC-DC-AC WIND GENERATION SYSTEM

摘要

A megawatt direct drive type squirrel-cage asynchronous generator AC-DC-AC wind generation system with a medium-voltage squirrel-cage asynchronous generator as a wind generator comprises a squirrel-cage asynchronous generator, a megawatt four-quadrant AC-DC-AC converter and a phase-shifting transformer. The converter is configured by converter chains composed of three power units connected in series. One end of each converter chains is connected together, and the other end of each converter chain is connected to the stator windings of the corresponding phase of the squirrel-cage asynchronous generator. The output terminal of each power unit in every converter chain is connected to the secondary windings of the corresponding phase of the phase-shifting transformer, and the primary-side three-phase windings of the phase-shifting transformer are connected with the three phases of the power grid. The wind generation system uses a medium-voltage squirrel-cage asynchronous generator, has small size, light weight, easy installment, free maintenance, no increasing gearbox and brush, and can improve the capacity of the wind generation system, reduce the difficulty and cost of manufacturing a large-capacity motor, improve system reliability, and be easy to low voltage ride through.