High Frequency Attenuation in Transmission Class Solid Dielectric Cable

High frequency attenuation in shielded distribution cable is well understood; however, this cannot be said of transmission class solid dielectric cable, which has a more complicated structure, including additional semiconducting ldquobeddingrdquo layers and a moisture barrier in the form of metal tape or corrugated metallic sheath. These additional elements cause new sources of high frequency loss relative to solid dielectric distribution cable. We report measurements of high frequency loss for transmission class solid dielectric cable with a corrugated copper sheath and for cable with a metal tape moisture barrier and wire screen (concentric neutral). Analytic approximations have been developed for the various sources of high frequency loss in these cable structures, and the analytic approximations have been checked using finite element analysis. Good agreement has been achieved between the computed and measured loss.