The Design Study Of The Direct-Driven Permanent Magnet Generator For Wind Turbine

Recently, the renewable energy such as wind power have been strongly encouraged because of environmental problem and shortage of traditional energy sources in the near future. Without the typical gearbox in wind-generating system and the disadvantages caused by gearbox, the PMSG(Permanent Magnet Synchronous Generator) is directly driven by the wind turbine at low speed, which makes the operation of the generator more liable.First, the meaning and background of wind power is described in this paper, then presents a review on the development of direct-drive wind power generation and the main types of generator in the direct-drive wind turbines. The second, the work principle of the generator is studied in detail, the design characteristics and the electromagnetic design methods of direct-drive wind power generation are discussed. And used the Visual Basic 6.0 as tool, developed the electromagnetism design program and software of which to improve the design efficiency. The third, The MW permanent magnet synchronous generator's static electromagnetic field and transient electromagnetic field have been analyzed in detail by the Maxwell 2D. The modle of the generator on full load has two different kinds of load, one is independent resistance load and the other is infinity electrical network load. The result of analysis compared with the calculative result of the calculative result by VB program confirmed the validity of design data about the MW permanent magnet wind power synchronous generator. At last, the SRM (Starting Resistant Moment) of direct-drive wind power generation is studied in this paper, the mechanism of the generation of the cogging torque is analysed and the methods of reducing the cogging touque is discussed. At the same time, the method of magnets shifting is studied in detail, and the method was achieved by the results of finite element simulation by the Maxwell 2D.