| As motor vehicle generator, permanent magnet generator has some advantages such as high efficiency, energy conservation, low carbon, large power and small size. But Permanent magnet generator has some disadvantages, for example, it is hard to adjust the output voltage of permanent magnet generator, when permanent magnet generator has high frequency the iron loss is high and the temperature is high and when permanent magnet generator is starting up the torque is high as well. So permanent magnet generator is adopted rarely in vehicle at present. This dissertation changes magnetoresistance by adjusting air gap in the magnetic circuit, based on the working principle of motor. When a permanent magnet generator runs low-speed it can adjust the air gap to small. When a permanent magnet generator runs high-speed it can adjust the air gap to big. It can level off the output voltage of permanent magnet generator. This dissertation presents a new idea, it can increase some air gaps in the magnetic circuit, and the size of the air gaps can be automatically adjusted with the speed. We simulate the permanent magnet generator which has the variable air gap by finite element method. We simulate the generator with the rotate speed between 1000rpm and 8000rpm, and we analyzed the output voltage of air gap. We explore the relationship between the rotation speed, the size of air gap and the output voltage. Simulation results are significant. When the rotate speed is 8000rpm, to increase the gap so that the output voltage to drop to 66%. When we not increase the air gaps the permanent magnet generator output voltage fluctuation range from 50.7～203.2V, and after we increase the air gaps the output voltage fluctuation range from 48.5-68.7V. This study shows that it can effectively improve the performance of permanent magnet generator because of Improvement of motor structure, the permanent magnet generator will be used as motor generator. This study has some positive effect.
|
PDF Full Text Request