Wind power meter with propeller-hysteresis braking - has interchangeable magnets and reversal material for different wind characteristics

摘要

The wind power meter has a load connected to a propeller generating a working power per revolution large in comparison to the propeller bearing frictional losses. Hysteresis magnetic braking is used to reduce the dependency of the measurements on the propeller rate of revolution. A further improvement in accuracy is achieved by adjusting or replacing magnets to suit local wind speed spectral changes. The number of revolutions is recorded as an integral value. The output power is produced by cyclic magnetic reversal of ferromagnetic materials moved relative to the fields of the permanent magnets. The magnets and the ferromagnetic material are easily removable and interchangeable. The ferromagnetic material is so arranged that the eddy current braking effect caused by its movement is small compared to the hysteresis braking effect.