PARTIAL DISCHARGE ANALYSIS FOR INSULATION SYSTEMS OF ELECTRIC ROTATING MACHINES WITH VARIOUS VOLTAGE STRESS

High voltage insulation is loosing its quality during the operation of high voltage machines and generators. Degrading high voltage stator insulation is the main reason for sudden breakdown of stator windings. Partial discharge measurements can reveal a lot of defects in stator windings of high voltage rotating machines with operating voltage more than 3,3kV. Partial discharge monitoring provides reliable information necessary for basic maintenance of stator windings of motors and generators. Submitted paper deals with partial discharge measurements in stator windings during the increasing of applied voltage.