Principle for measuring steady-state relaxation polarizability of insulating dielectric based on polarization current time domain spectrum

The invention discloses a principle for measuring the steady-state relaxation polarizability of an insulating dielectric based on a polarization current time domain spectrum, belongs to the field of dielectric parameter measurement of the insulating dielectric, and mainly solves the technical problems of low efficiency and large error of an existing method for measuring the steady-state relaxationpolarizability of the insulating dielectric. The basic principle of the present invention is characterized by testing and recording a polarization current time domain spectrum of the insulating dielectric under the action of direct-current voltage, and obtaining a polarization absorption current Ip (t) reflecting a relaxation polarization behavior through least square fitting of the polarizationcurrent time domain spectrum based on a pervasive relaxation polarization law (Ip (t) = At-n) or a relaxation polarization Debye expansion model; and integrating the polarization absorption current Ip(t) in a time domain space