METHOD FOR PARTIAL DISCHARGE DETECTION AND BREAKING SPARK MEASUREMENT IN DYNAMOELECTRIC HIGH-VOLTAGE MACHINES,AND AN APPARATUS FOR PERFORMING THE METHOD

摘要

A method for partial discharge detection and breaking spark measurement in a dynamo-electric high-voltage machine, especially for monitoring insulation status during operation of a stator winding and connected electrical output lines in a turbo-generator. The generator includes a stator having a stator winding and a stator housing, a rotor with an exciter winding and a shaft, defining an air gap between the rotor and the stator. At least one oil lubricated slide bearing supports the shaft of the rotor with a bearing shell being electrically insulated from the ground. The method includes decoupling the frequency spectrum of high-frequency electromagnetic oscillations resulting from the occurrence of partial discharges or breaking sparks and delivering the frequency spectrum of high-frequency electromagnetic oscillations to a partial discharge measurement apparatus. The frequency spectrum of high-frequency electromagnetic oscillations introduced into the machine shaft through the air gap in the event of partial discharges inside the stator winding or the output lines are decoupled while utilizing the machine shaft insulated by a film of lubricant as a antenna. Then the frequency spectrum of high-frequency electromagnetic oscillations are delivered to the partial discharge measurement apparatus by using the bearing shell of the oil lubricated slide bearing as transmission element.