Power cable intermediate joint insulation detection method based on dielectric spectrum method

The invention discloses a power cable intermediate joint insulation detection method based on a dielectric spectrum method. The method comprises the following steps of preprocessing a power cable intermediate joint insulation layer and preparing a sample, performing broadband dielectric spectrum test on the sample, processing the test data to obtain a spectrogram of the dielectric constant changing along with temperature and frequency, obtaining a spectrogram of dielectric loss angle tangent changing along with temperature and frequency, drawing a dielectric temperature spectrum and a dielectric frequency spectrum of the same sample, formulating a rule for judging insulation aging and degradation states of the silicone rubber by the dielectric spectrum, and comparing the dielectric constants/dielectric loss angle tangent of the same sample at different temperatures, and judging the insulation life of the intermediate joint of the power cable by adopting a rule. The aging and degradation states of the silicone