Polymer Composites for Power Cable Insulation

In recent years, growing awareness of global environmental conservation has increased the demand for power leveling through inter‐grid connections between nations or islands, and the introduction of renewable energy raises more necessity of energy leveling and remote connections between power‐generation facilities and power demand area. There is a lot of market interest in high‐voltage direct current (HVDC) technology, which is advantageous for long‐distance power transmission. HVDC power cables are playing an important role in this to connect HVDC‐generation facilities and the existing power network efficiently. Solid insulation power cables, in particular, are attracting attention worldwide and various insulation materials have been proposed. Though cross‐linked polyethylene (XLPE) cable is widely used for alternative current (AC) transmission, if attempts are made to adapt AC‐XLPE cables for DC transmission as significant electric field enhancement by space‐charge accumulation may occur, then breakdown would take place especially during surge voltage in opposite polarity and polarity reversal. Therefore, it is desired to innovate a special insulating material for DC transmission to suppress the accumulation of space charge.In this chapter about such insulating material for DC transmission cable, nanocomposite that is composed from polymer materials as a matrix and nanofiller, polymer blend, and copolymer as kinds of composites in a broad sense are described. And for the real production of the nanocomposite materials in the near future, to increase the performance and reliability of the production and a deeper understanding of insulation and dielectric phenomena, some issues and perspectives are shown.