HVDC Cable Design and Space Charge Accumulation. Part 3: Effect of Temperature Gradient [Feature article]

The aim of this article is to investigate the extent of space charge accumulation due to a temperature gradient in comparison with other charge-supply mechanisms, particularly injection from the electrodes. For this purpose, space-charge measurements were carried out on HVDC cable models under application of different temperature gradients across the cable insulation, above and close to the threshold field for space-charge accumulation. The main results, consisting of space-charge patterns and extracted quantities, are discussed here.