Abstract
It has already past 20 years since the first Adjustable Speed Hydro Generator Narude Unit No. 1 22MVA was put into commercial operation as an experimental unit for Ookawachi Adjustable Speed Generator/Motor 395MVA/388MW in June 1987. The adjustable speed generator (generator/motor) has a cylindrical rotor with 3phase winding like winding type induction motors. Its 11kV class winding must endure against 1,000G class centrifugal force which is much higher than that of pony motors for pumping storage generator/motors. Technologies for the rotor winding were developed as a combination of well experienced technologies on large rotating machines and specially developed material and manufacturing technologies on Nuclear Fusion Experimental Reactors such as Heliotron E and JT-60.
