Report KD 716 which describes the 2-bladed VIRYA-2.3 is replaced by report KD 717 which describes the 3-bladed VIRYA-2.7. The VIRYA-2.3 was replacing the VIRYA-2.22. So finally the 2 bladed VIRYA-2.22 with stainless steel blades is replaced by the 3-bladed VIRYA-2.7 with wooden blades. Both windmills make use of the same generator of Hefei Top Grand type TGET260-0.5KW-350R.
Advantages of the VIRYA-2.7 above the VIRYA-2.22 are that the output is substantial higher, that the noise production of a rotor with wooden blades is lower than that of a rotor with cambered stainless steel blades, that no special tools are needed for manufacture of the blades, that a 3-bladed rotor has no fluctuating gyroscopic moment in the rotor shaft and that it looks better than a 2-bladed one. In figure 5 of KD 717 it can be seen that the matching in between rotor and generator is very good (if the estimated characteristics of the generator are correct). In figure 6 of KD 717 it can be seen that the Pel-V curve already starts at a wind speed of 2.7 m/s and that the maximum power is 425 W which is very good for a wind turbine with a rotor diameter of 2.7 m/s and a rated wind speed of 9 m/s.
