My new report KD 622 is now available. The title is: "Ideas about a pitch control mechanism for the 2-bladed rotor of the VIRYA-5 windmill meant for connection to a 34-pole PM-generator for driving an asynchronous motor of a centrifugal pump. Description of the 34-pole generator." The report can be copied from my website:
www.kdwindturbines.nl at the bottom of the menu KD-reports.
A part of the information in this report is also given in report KD 614. However, chapter 9, in which a simple pitch control system is described, is new. Chapter 10 is also new. In this chapter, a double vane is described which keeps the rotor perpendicular to the wind. This vane was tested already about 30 years ago and it works nicely. It has a large moment of inertia and so it limits fast movements of the head. The gyroscopic moment is therefore limited very effectively. The pitch control system makes only use of the aerodynamic moment to steer the variation of the blade angle and there is no synchronisation mechanism in between both blades. This makes the system rather simple and I think that therefore it can be built in developing countries.
