Influence of Temperature Transient on Frequency Domain Dielectric Response of Oil-Paper Sample

The health of the oil paper insulation of a transformer can be monitored by using a dielectric testing technique well-known as Frequency domain spectroscopy (FDS). The insulation response profile obtained from FDS test is influenced by measurement temperature. The time required by dielectric to reach thermal equilibrium is long. Therefore, it is possible that FDS tests are conducted during temperature transient conditions. This may affect the FDS profile and corresponding analysis. This paper focuses on the laboratory experiments carried out on oil-paper sample to analyze the effect of temperature transients on the FDS measurement profile. To compensate this effect of transients on FDS profile, a methodology is proposed further in this paper (on a sample).