The Application of Dielectric Modulus in the Oil-impregnated Paper Insulation

Frequency Domain Spectrum analysis method (FDS), for its lots of advantages, has been widely concerned and applied in state characterization of insulating materials and insulation diagnosis of power equipment. However, in the current research, the characteristic parameters of FDS are not reliable and accurate enough in the field of bushing insulation damp diagnosis. This paper aims to introduce the new concept of dielectric modulus, the inverse of complex permittivity, to the oil-impregnated paper. The dielectric modulus shows great characters in low frequency region, meanwhile the peak of the imaginary part moves to the higher frequency when the water content increases.