The Correlation and Balance of Critical Material Properties for DC Cable Dielectrics

To answer the question “What is the ideal material for DC cable? ” one needs to develop materials with controlled electrical conductivity, reduced space charge accumulation and higher dielectric strength with bounded realizable parameters. With careful characterization and thorough understanding of these properties, their correlation and balance, may bring the ability to engineer desirable dielectric properties for the use of DC cable insulation within the space of physical materials. This paper will discuss the properties needed for the insulation system intended for MVDC cables and how a next generation of MVDC material can be formulated with proper balance between key electrical properties. The aim of this paper is to develop a relatively simple formalism which includes the correlation between the conductivity and space charge based on two physical parameters, activation energy $(\xi)$ and mean trap separation $(\lambda)$ . The study suggests optimal DC insulation can be designed with activation energy in the range of 0.4-0. SeV with relatively high trap density $(\lambda .