Investigations on Correlation between Breakdown Voltage and Diagnostic Measurements for an Insulation System used in Rotating Machines

The remaining electrical strength of the insulation can be determined by breakdown voltage tests, which have the disadvantage that these tests belong to destructive methods, thus the insulation system will be damaged and cannot be longer used. In order to avoid this procedure it is preferred to evaluate the condition of the insulation by non-destructive so called diagnostic procedures. This is possible if there is a correlation between the results of breakdown voltage tests and non-destructive methods, which is often not the case. In order to check how the results of the breakdown voltage tests can correlate with the results of different non-destructive diagnostic measurements, a series of diagnostic investigations as partial discharge, dissipation factor and insulation resistance…