Health Assessment of Oil-Paper Insulation Using Short Duration Frequency Domain Response

Cellulosic paper moisture is widely considered an important factor for assessing the condition of transformer insulation. An increase in paper moisture accelerates the aging of the cellulosic parts and reduces the lifespan of the transformers. The proposed paper presents a methodology that is capable of identifying moisture within a few seconds. The methodology is based on an analysis of insulation response measured at 1 Hz. The method employs a Lissajous pattern-based technique for identifying dissipation factor (tan $\delta $ ) and % paper moisture in oil paper insulation. Unlike available frequency domain spectroscopy (FDS)-based commercial equipment, the proposed method is observed to take significantly less time to operate without sacrificing accuracy.