Research on propagation characteristics of high frequency signal in high voltage cable

The relative permittivity and conductivity of the semi-conductive layer and semi-conducting resistance water layer of the high voltage cable were measured by the broadband dielectric spectrometer in the frequency range of 1-100MHz. Based on the measured results, the transmission characteristics of the partial discharge signal of the high voltage XLPE cable were simulated and calculated and finally the theoretical models were obtained. Besides, sinusoidal signal measurement experiment was done on cables of 110kV and 220kV with different lengths and types. It is found that attenuation degree of signal propagation becomes serious with the increase of cable's length and signal frequency, which verifies the effectiveness of high-voltage cable partial discharge propagation model. It is the semi-conducting layer that has serious attenuation characteristic to high frequency signal.