PD Measurement of Rotating Machine for Condition Monitoring

A Generator in power system is an extremely critical equipment and availability of this to be maintained at highest reliability. Online PD measurement of rotating machine is a good and evolving condition monitoring technique apart from well establish offline testing technique. This paper discusses the results of online PD measurements done on Hydro Generators, with different type of coupling capacitors (80 pF & 2 nF). PD measured in absolute values pC (Pico- coulombs) and analysis of PRPD are also briefed for results. Cases of failure of two other thermal VPI generator are discussed. Case studies about failure of air-cooled generator were discussed, with detail reason and corrective action. PD confirmation by capacitance and Tan Delta Measurement of rotating machines was also explored in this paper.