Design Of 100kW Hybrid Excitation Wind Generator And Reactance Calculation

Hybrid excited generator is widely used in wind power system because the excitation can be controlled and no brush is adopted. In hybrid excited wind generator, permanent magnet is used to provide main flux, and the constant voltage is guaranteed by electrical excitation. According to the characteristics of hybrid excited wind generator, the main points of this thesis are as follows:Firstly, according to the special structure of surface mounted permanent magnet machine with pole shoe, analytical formula is derived to calculate its armature reaction reactance. In this paper, the curves of coefficients kpd,kpq is computed by finite element software. Fractional harmonics impacts on harmonic leakage reactance is analyzed in allusion to permanent magnet machine with fractional slot concentrated winding, and the leakage factorΣs is also summarized. Considering the MMF harmonic effect, an effective finite element method is used to calculate synchronous reactance in this paper, and the calculation results are verified by tests.Secondly, thermal calculation method for hybrid excited wind generator is deeply studied.3D finite element method is used to calculate the temperature filed. The equivalent thermal conductivity of insulation is revised according to the experiment results. By analyzing the influence of heat dissipation area on generator cooling effect, a conclusion can be made:with the increase of cooling area, the increased cooling effect is reducing. By analyzing the influence of wind speed on generator temperature distribution, the following conclusions can be achieved:At low wind speeds, with the reduction in wind speed, the rate of temperature rise change is increased. At high wind speeds, with the increase in wind speed, the rate of temperature rise change is decreased. On this basis, thermal loads of hybrid excited wind generator that power level is between 100kW and 1000kW are given under different wind speeds.Finally, the effect of reactance and saliency ratio on voltage regulation is investigated in this paper. The field winding losses, efficiency and temperature rise of the generator are calculated at different choices of Ie=0 under different working conditions. A conclusion is obtained:when the speed of Ie=0 is between 101r/min～104r/min. the generator has a better efficiency and uniform temperature distribution under different working conditions. The research work is applied to the design process of 100kW hybrid excited wind generator.