A new model for recovery voltage of oil-paper insulation system

A theoretical description of recovery voltage on oil-paper insulation systems based on interfacial charge movements is proposed as an alternative to traditional RC-circuit model. The traditional model produces responses that are linear superposition of exponential functions. However, the recovery voltage observed in actual time-domain measurement does not conform to the exponential descriptions. This is especially true to the tail of recovery voltage which decay sub exponentially at the rate of 1/√t rather than exponentially. More data points need more time constants to describe because the curve is intrinsically non-exponential. The interfacial charge model also suggests that the recovery voltage of pressboard can be viewed as reflecting two major processes of charge movements and transfer.