Measurement of ionic impurities and thermal properties of semiconductive shield for 154 KV power cable

In this paper, we measured ionic impurities and physical properties by change of carbon black content, a semiconductive material for underground power transmission. Specimens were made into sheet form with three existing resins and nine specimens for measurement. The ionic impurities of the specimens were measured by an ICPAES (inductively coupled plasma atomic emission spectrometer), and a density meter measured the density of specimens. Specific heat (Cp) and melting temperature (Tm) were measured by DSC (differential scanning calorimetry). The ranges of measurement temperature were from 0 °C to 200 °C, and heating temperature was 4 °C/min. Ionic impurities were measured to be high according to an increase of the content of carbon black from this experimental result, and density was also increased according to these properties. In particular, the impurity content values of existing resins were measured at more than 4000 ppm. Specific heat and melting temperature from the DSC results were lowered according an increase of the content of carbon black. That is, the ionic impurities of carbon black containing Fe, Co, Mn, Al and Zn are due to increase of the collision number of times according to an increase in the vibration of those by the applied heat energy.