Overview of insulating materials system for power cable applications

A review of solid dielectric insulating materials used for power cable applications is provided. The history of the development of these insulations and their performance differences are discussed. Mechanisms for electrical degradation from bond energies based on thermodynamic and kinetic aspects are proposed. The critical factors contributing to electrical degradation of solid dielectrics under stress include morphological effects, molecular structure, the presence of additives, and the nature of the additives. Differences among these various insulation materials, particularly for polyethylene or ethylene-propylene rubber (primarily filled EPR or EPDM), in these key parameters, as well as differences between different polyethylene structures, are reviewed. A perspective on the future direction for improved insulation materials, and the needs driving these improvements, will also be provided.