Research On Low Wind Speed Magnetic Levitation Vertical Axis Wind Turbine

Wind energy resources in low wind speed areas are widely distributed in China,accounting for about 68% of the available wind energy area.However,wind energy resources in low wind speed areas are almost not exploited,which is undoubtedly a great waste of wind energy resources.Therefore,the rational and effective development and utilization of wind energy resources in low wind speed areas is of great significance to convert localy and utilize the wind energy resources,and to supplement the shortage of fossil energy,adjust reasonably the energy structure of our country.Vertical axis wind turbine(VAWT)has been used in small and medium power level wind turbine due to its advantages such as no yaw system needed,low starting wind speed and easy installation.Because there's no mechanical friction,maglev vertical axis wind turbine(MVAWT)can greatly reduce the starting resistance moment,so it can further reduce the starting wind speed.It is especially suitable for the development and utilization of wind energy resources in low wind speed areas.Therefore,it is of great practical significance to develop a low wind speed MVAWT to solve the problem that wind energy resources in low wind speed areas are not effectively utilized for a long time.In this paper,both a wind turbine and a direct-driven permanent magnet wind generator of a low wind speed MVATW are designed.Firstly,through the design of the parameters of the wind turbine,a wind turbine of 1kW MVATW is preliminarily designed.At the same time,its aerodynamic performance is predicted through the Matlab program code written by the calculation steps of the dual multi-flow tube model.The results show that the output of the designed wind turbine can reach 1kW,and meet the corresponding requirements of the wind energy efficiency.Secondly,the numerical simulation of the preliminarily designed 1kW wind turbine is carried out.The results show that the preliminarily designed 1kW wind turbine does not meet the design requirements for low wind speed start-up.For this purpose,the preliminarily designed1 kW wind turbine is optimized using the optimization method combining the blade airfoil optimization with the optimization of the structure parameter of the wind turbine.The results show that the starting torque and wind energy utilization efficiency of the optimized wind turbine has been greatly increased,and the start-up wind speed has been effectively reduced,as well as the weight of the wind turbine.Therefore the design requirements for the wind turbine of the low speed MVATW is meted.Finally,a 1kW direct-driven permanent magnet wind generator matching with the abovedesigned 1kW wind turbine is designed.First,based on the empirical formula of traditional generator and the calculation example of permanent magnet synchronous generator(PMSG),the basic parameter of the 1kW direct-driven permanent magnet wind generator is determined by the design and electromagnetic calculation of the generator.Then,its basic model was established in the RMxprt module.Finally,the basic model was imported into Maxwell 2D for the analysis of static magnetic field and transient magnetic field.The comprehensive analysis shows that the design of the designed 1kW direct-driven permanent magnet wind generator is reasonable.