Theory of Stress Distribution in Insulation of High-Voltage DC Cables: Part I

The theory of stress distribution in the insulation of high-voltage direct current (dc) cables is refined by accurately including the effects of heating by the leakage current. The results have specific implications with respect to thermal instability; in particular, a new type of instability is identified. Numerical examples are presented, and certain published experimental data are shown to support the theoretical results.