Electromagnetic Field And Thermal Analysis On 1.5MW Half-direct Driven Permanent Magnet Wind Generator

With the world's energy crisis aggravation,renewable energy research has been extensive attention,wind-driven generator is the one of techniques that the fastest growing and the most widely used in renewable energy, large-scale grid-type wind generator is an important development direction for wind power generation. In this dissertation, large-scale grid-connected wind turbine permanent magnet electromagnetic field and temperature field has been studied.Firstly, in this dissertation, a 1.5MW half-direct permanent magnet synchronous wind generator is investigated, for which three structures with different Slot/Pole Ratio are designed, and the armature windings are also determined. First, the finite element analysis model for the generator is established, based on which the electromagnetic field of machine operation with rated load and non-load are studied, Then, give three synthetic air-gap flux density map with load; within a motor unit; calculate the harmonic content of winding magnetic force with load; the magnetic flux leakage at different position with radial thickness is analyzed, as well as the influence of rotor and magnetic structure on air-gap field.Secondly, the 2D thermal analysis model of the machine is established according to heat transfer theories after the determination of effective heat transfer coefficient of rotational air, the temperature fields of the 1.5MW half-direct permanent magnet synchronous wind generator with three structures are calculated and the variation of temperature at stator windings and the temperatures at frame outer-surface,stator windings and rotor are comparatively analyzed among three machines with different structures, the temperature distributions are obtained base on the heat transfer coefficients determined from fluid and heat transfer theories and flat wall heat transfer respectively.Finally, compare and analyze the temperature field for two wind generators with 252 stators slots,32 poles and permanent magnet placed in a different position, calculated their temperature in different wind speed with non-load and the temperature in rated wind speed with load, which could provide use-full theoretical reference for cooling system design in this kind of machine. At last, the comparisons of the analysis results on a small wind generator with same structure and test data are proposed, which may be meaningful for the design of half-direct permanent magnet large wind generator。...