Comparative testing of simple terminations of high-voltage cables

This section describes the layout of the test setup, the design of the tested cables, and the experimental routines. Six different types of 2124 cable shield termination were tested for leakage current and dielectric strength. The main results can be summarized as follows: (1) Shrink sleeve strongly affects ionization phenomena, effectively suppressing corona discharge. (2) Flush cutting a shield leaves loose short strands, which increase the probability of main insulation damage. (3) Folding the shield back over an O-ring decreases the electric field strength, leaves no loose strands, and decreases the probability of main insulation damage. This is recommended for dc applications. (4) Stress-grading tapes reduce (and greatly stabilize) leakage currents, at a level around 1 nA at 100 kV and room temperature. They also increase the breakdown voltage to approximately 130 kV for a 15-cm length of insulation. They are recommended for pulsed operation and critical DC applications.