| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 100 === The researches of wind generator are giving first place to horizontal axis wind generator in the world nowadays. Then the mainly options of generators are double-fed induction generator and permanent magnet synchronous generator. The permanent magnet synchronous generator in this thesis has following advantages: high efficiency, low noise and small volume, etc. The most important characteristic is the excited part of rotor uses permanent magnet(NdFeB) so that we don’t need extra excited circuits. But magnetization curve of permanent magnet is sensitive to temperature. The problem of generator overheat cause the efficiency of permanent magnet declined and the devastation of winding so that reduce the efficiency and life of generator. So, the main purpose of this thesis is to design an effective method of thermal to overcome the elevated temperature of generator. This thesis investigates the generator power dissipation first and the lost can be classified into copper loss, core loss, mechanical losses and stray losses. The core loss is calculated by magnetization analysis result of electromagnetic field analysis software Maxwell_2D. The core loss is 24.2W in no load operation, but core loss is 24W and copper loss is 64.45W when it operates in adding 28Ω in each phase. Total power dissipation is 88.45W, so the excepted efficiency of generator is 93%. This research uses the hydromechanics analysis software Fluent. Then compare the consequence between experiment and simulation of prototype permanent magnet synchronous generator. The consequence of comparison shows that the error values are in 2.5℃ between simulation and experiment. And the highest temperature area of whole generator is winding, it is enough to prove the simulated method and model structure are reliable in this thesis. By improving the housing and fin to solve the heat problem. We can see from simulation, radial fin of the cooling efficiency then axial fins when generator in natural convection. Can reduce the temperature of winding to nearly 78℃. At last, improve the thermal of overheat area of generator. In reality, the generator is operated by wind. So, we can except the generator will operate in windy state. When the generator is in 12m wind environment, can reduce the temperature of winding to nearly 49℃ and its temperature is much lower than temperature range of permanent magnet (80℃). In the end, although the accuracy of calculated power disspation can not reach 100%, it still shows the really good reliability by consequence of comparison between experiment and simulation basically. For researchers, it can save lots of time to develop the products and be a reference for choosing fit temperature range of permanent magnet in raising temperature situation of generators and motors.
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