Large generator rotor plant life extension-modification base load to multi-start capability

The author gives a brief outline of the modifications made to large generator rotors of 200 MW and above which were originally designed for base load operation and now have to be capable of multi-start operations. Many of the units have already operated for 100000 hours and more. With certain families of rotors their operating problems are well known, and the modernisation recognises these defects and eliminates them