The direct-current (DC) electric field distribution of polymeric insulation layer determines the long-term operation characteristics of the cable, mainly affected by different parameters of material design and cable operation. In this paper, the DC electric field distribution characteristic of grafted polypropylene cable insulation have been studied by material tests, established the correlation characteristics between electric conductivity, thermal conductivity and electric field strength, combined with multi-physical field simulation. The results show that the field strength reversal has occurred at steady state, and the maximum electric field strength variation trend at the start of the field strength reversal characterizes its variation at steady state.
 

grafted modification,polypropylene materials,multi-physical field simulation,DC cable,field strength reversal