The Design And Demagnetization Study Of The C Core Permanent Direct Drive Wind Turbine

In today’s society the serious energy crisis, environmental pollution, and greenhouse effect is increasingly intensify, So looking for clean new energy to replace the traditional fossil energy is an urgent task in human society today. wind is widely distributed, containing the total use of wind power can achieve zero pollution, so the development of wind power generation has been becoming the current hot spot. The core component of the current wind power wind turbines are mainly divided into two major categories of doubly-fed induction and permanent magnet direct-drive, and permanent magnet direct drive wind turbines because its leaves out the gear box structure and make the generator system losses, improve efficiency, reduce the maintenance workload, improve the stability of wind power unit operation, therefore is considered to be the future development trend of wind turbines. However the traditional permanent magnet direct-drive wind power generator stator between electromagnetic suction and the cogging torque is big, makes the motor structure weight is big, low wind speed start is difficult, and the iron loss is serious.And C type rotor, coreless permanent magnet direct drive wind turbines not only keep the traditional permanent magnet direct-drive wind turbines of the many advantages, but also eliminate the cogging torque of the motor and stator loss, reduce the structural weight of the motor, has better low wind speed startup performance directly. As lightweight composite materials with high strength and solid development of coreless motor winding fixed in mature technology, coreless motor is bound to have a better development prospects.In this paper, the first part introduces the background significance of wind power, the classification of modern wind turbines, the permanent magnet direct drive wind turbine research status, especially made more comprehensive review of coreless motor; Traditional coreless motor mainly axial structure, then the axial structure are not suitable for high power situation, thus developing the radial structure coreless motor is a new breakthrough point, this chapter now has successfully developed the large radial structure of general design method of the coreless motor and reasonable performance parameters are summarized, describes the suitable for C type direct drive wind turbine rotor, no core of the characteristics of the structure.The second part discusses the general method of permanent magnet motor design process, and follow the principle of permanent magnet motor design process, through the design principle, deduces the mathematical model of motor.The third part analyzed the C type rotor permanent magnet direct-drive wind turbine structure characteristics, development process, working principle.C type iron core of motor magnetic circuit characteristics are analyzed, and based on magnetic circuit characteristics combined with finite element analysis software of parametric function C module reasonable structural parameters are obtained.The fourth part through a precise drawing software pro/e to build the motor model and Ansoft Maxwell’s 3 D finite element simulation software to complete the electromagnetic performance simulation, through post-processing no-load and load, short circuit conditions the rationality of the design of motor performance parameters of the validation. Last part of the use of the method of finite element simulation of C type rotor permanent magnet direct-drive wind turbines demagnetization characteristic were studied, meet in magnetic circuit method, the finite element method can be more accurate to get the local demagnetization of the permanent magnet, can conclude from the simulation results that the worst moments of the permanent magnet demagnetization field loss is most serious position, problems about magnetism loss prevention for motor design has certain guiding significance.