Method for partial discharge detection and breaking spark measuring in dynamo-electric high-voltage machines, and an apparatus for performing the method

US4814699A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Reinhold Koziel · Neheim, DE
• Kurt Fork · Neunkirchen, DE
• Jurgen Weidner · Essen, DE

Key dates

• Filing date: Apr 11, 1988
• Grant date: Mar 21, 1989
• Expiry date: Apr 11, 2008

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R31/1227
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

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 spec…