Compared with horizontal axis wind turbines, the development of domestic vertical wind turbines has been difficult, mainly because the power of the vertical axis wind turbine has not been able to get up. The horizontal axis wind turbine has been developed to the megawatt level, while vertical wind turbines are still hovering around the kilowatt.
Through the analysis of various aspects, it can be seen that the vertical axis is not capable of making high-power wind turbines, so it can only be popularized in the household. In fact, according to baez, the flowing air should be seen as a whole. The air flow is considered as a plane when calculating the wind volume of the horizontal axis wind turbine. In fact, airflow should be treated as a three-dimensional structure. Whether the impeller section of the vertical axis or the impeller section of the horizontal axis, whether the upper or the lower wind, the air in the area centered on the tower is considered to be a complete fluid.
In the design of traditional wind turbine, an important parameter has been neglected, which is the leverage effect of fan blades. In general, the calculation of wind force only calculates the air flow, but never considers the leverage effect of the blade Angle to enlarge the wind force.
Vertical wind turbines, a home if the impeller diameter increasing, which is to support the blade to lengthen the length of the connecting rod, the wind turbine impeller speed will slow, but the torsion axis. In this case, as long as a gearbox is added like a horizontal axis wind generator, the high-power household vertical wind generator is basically ready to take shape.
But only so much of the home vertical wind turbines that have been modified are extremely resistant to wind power, and the ability to survive in strong winds is so weak that wind turbines can't work for long. This time can consider variable wing household vertical wind turbines, the principle of wind turbines is the same with most variable fins, by computer control blade under the environment of low wind speed will leaves fully expanded, have strong wind weather using the contraction blade for the purpose of protection of wind generator.
The household vertical wind turbine blade impeller diameter is very big, when fully expanded based on lever principle can amplify wind several times, is passed on to the centre drive shaft after only need a set of planetary gear can obtain high speed torque output, when the wind more than security restrictions, can be blade contraction, reduce the effects of wind on the fan.