Practical foundations of the RVM (recovery voltage method for oil/paper insulation diagnosis)

The original research into the application of Recovery Voltage Measurement to diagnosis of oil-paper insulation is described in detail. The goal of this research was to thoroughly review the conventional diagnostics used on oil immersed paper insulation systems in large power transformers and, after fundamental laboratory measurements and on-site measurements of power transformers, to propose a method for the future dielectric testing of insulation in large transformers in service. The results of the basic research are further illuminated by examples drawn from the numerous tests since performed on actual test objects in the field, mostly large power transformers, which give insight into the strengths and limitations of the method. A few measurements on oil-paper insulated cables suggest a yet to be explored potential application to the diagnostic testing of cables.