Research On Starting Resistance Torque And Magnetic Bearings Of Small Scale Wind Turbine Generator

Utilization of the wind power is an effective way to solve the problem of energy shortage and power wake in China. However, according to statistics in China, the area all over the country that rich in wind energy is only about 26%. Currently the large scale and small scale wind turbine generators have a cut in wind speed higher than 5m/s and 3m/s separately. So we have to develop the low wind speed turbine generators to expand the using of wind energy in the 74% parts in our country and increase the annual time of power generation. It's an essential way to make the wind power as a strategic resource. Small scale wind turbine generators are low cost, no pollution, low energy consumption, structure flexible and easy installation & maintenance. It's used wildly in regions that the wind energy resources are not rich or cities to solve the power shortage and reduce CO2 emissions. However, there are a great starting resistance torque and a high cut in wind speed in small scale wind turbine generators currently. The key problem of expand the effective area for wind power in our country is to develop the low wind speed turbine generators.Magnetic bearings are no mechanical contact, no wear, no lubrication, long life, maintenance-free and no pollution. By using the permanent magnetic bearing to replace the mechanical bearings one can eliminating the mechanical friction and reducing the starting resistance torque of wind turbine generators. We need to study the influence factors of starting resistance torque in maglev wind turbine generators, the influence of permanent magnetic bearings and the requirements of the permanent magnetic bearings in maglev wind turbine generators. The researches in this dissertation are as follows:1. Study the staring process of wind turbine generators and find out the relationship between cut in wind speed and starting resistance torque. Analyze the factor that causing the staring resistance torque and built the mathematic model of starting resistance torque of small scale wind turbine generator when considering the influence of eccentricity.2. Calculate magnetic force and magnetic field in the air gap of the small scale wind turbine generators by using FEM. Analyze the influence of the generators structure and the supporting characteristic to the resistance torque.3. Meet the special requirements of the supporting characteristic of maglev wind turbine generators. Analyze and compare the supporting characteristic of several radial permanent magnetic bearings with different structures and magnetization directions and compare two axial stacking permanent magnetic bearings.4. Designed and manufactured a small scale maglev wind turbine generators. Tested its starting resistance toque and compared with the theoretical analysis results.