Partial discharge on-line measurements with continuous monitoring as invaluable tool for assessing insulation quality and maintenance planning

Authors share their experience with 15- channel continuous Partial Discharge (PD) monitors applied to medium voltage rotating machines, apparatus and substation equipment, using variety of PD sensors. Real life examples illustrate the condition-based paradigm “measured-inspected-confirmed-repaired” that clearly purports this totally nonintrusive and effective on-line diagnostic technology. Use of stator RTDs as PD sensors offers an inexpensive solution for attenuation problems, especially in large rotating machines. Continuous monitoring assures that high variations of PD activity will not be overlooked in comparison with periodic tests. The discussed technology will help in making intelligent and accurate maintenance decisions, significantly improving effectiveness and quality of insulation repairs.