Acquiring Polarization and Depolarization Current with less Interference by Translating Dielectric Response from Frequency to Time Domain

Dielectric response measurement is a kind of nondestructive measurement to evaluate the condition of the insulating systems. The method used in time domain is Polarization and Depolarization Current (PDC), while in frequency domain is Frequency Dielectric Spectroscopy (FDS). As FDS has stronger anti-interference ability than PDC, the paper presents a method to translate dielectric response from frequency to time domain based on Fourier series. Define different kinds of frequency spectroscopy of oil-paper insulation based on H-N equation and XY -model, then translate the dielectric response of oil-paper insulation from frequency to time domain. It is concluded that the low frequency band of spectroscopy affects the whole period of current while the high frequency band only affects the initial period (O”'2s) of current. Additionally, the range of dielectric frequency spectroscopy recommended is from 1 mHz to 10Hz to get satisfying PDC data, as wider range of spectroscopy has few influence on polarization/ depolarization current computed.