Principle for measuring infinite high-frequency relative dielectric constant of insulating dielectric

The invention discloses a principle for measuring an infinite high-frequency relative dielectric constant of an insulating dielectric, and solves the technical problem that the infinite high-frequencyrelative dielectric constant of the insulating dielectric cannot be accurately measured. The basic principle of the invention is as follows: a high-voltage direct-current power supply is adopted to polarize a measured dielectric medium; then, an acquisition system consisting of an electrometer, an electrostatic voltmeter and a computer is adopted to achieve acquisition and recording of short-circuit current and a return potential time domain spectrum of the measured insulating dielectric medium; the initial moment change rate of the return potential is accurately obtained through least squarefitting, and measurement of the infinite high-frequency relative dielectric constant epsilon infinity is obtained through a formula according to the initial moment change rate of the return potentialand the short-circuit curr