New measurement method of displacement susceptibility based on time-domain current and potential combined spectra

Displacement susceptibility is a very important parameter to characterise the displacement polarisation of dielectrics. Two methods based on the time-domain current and potential combined spectra are proposed to measure the displacement susceptibility. One is based on the time-domain polarisation current and decay potential combined spectra, and the other is based on the time-domain depolarisation current and recovery potential combined spectra. The principle of the proposed methods are verified by simulation. In addition, a measurement system for the two proposed methods is built and is used to measure the displacement susceptibility of transparent organic glass and opaque nonlinear field grading materials. The experimental results are compared with those of the present optical method and the frequency-domain method. Simulation and experimental results show that the proposed methods for the measurement of displacement susceptibility are feasible and practical, which lays a foundation for the research on the polarisation characterisation of dielectrics.