Report KD 511 is replaced by report KD 532. Both reports describe the VIRYA-3.1 with a rotor made of Roofmate and glass fibre. The rotor in KD 532 has a design tip speed ratio of 7 in stead of 6.5 as used in KD 511. The matching with the generator for 24 V battery charging is better for a design tip speed ratio of 7.