A new low frequency high voltage insulation analyzer usingtransient methods

摘要

The authors present the results obtained on several aged cableinsulation types using very low frequency (⩽1 Hz) tan δmeasurements performed in the laboratory. The large changes in tanδ recorded as a function of aging prompted the development of afield instrument capable of performing high-voltage low-frequencymeasurements on long lengths of aged cables. The authors present thecritical requirements which must be met in designing an instrument forperforming such low-frequency measurements in the field and provide anillustration of typical results. Preliminary measurements indicate thatthe analyzer will provide a technique with which to evaluate aging ofpower, control, and instrumentation cables in power stations