Electrical Properties of Semiconducting Tapes Used in HTS Power Cables

In this paper we investigate the electrical properties of semiconducting tapes used for field grading applications in high voltage technology. Direct- and alternating-current resistance of the samples are measured at cryogenic temperatures between 18-300 K. Two different experimental setups are used due to the resistivity levels of the samples. It is observed that the samples have ´U-shaped´ temperature dependence of resistivity corresponding to metallic and insulator type character for temperatures over and below 170 K, respectively. The samples resistivities can be used for diagnostics and fault analysis purposes equivalent circuit models.