Comparative testing of simple terminations of high-voltage cables

In HV systems, cable terminations are one of the weakest links. The majority of failures occur on the ground shield side. This side is especially stressed by the electric field in free space connections. Field control and rigorous technological processes are key to reliable functioning. The first was realized for a century by stress relief cones in conjunction with solid dielectric fillings. Later, stress-grading nonlinear materials in the form of paint, tapes, and tubes were used with much success (see, e.g., [1]-[3] and their bibliography). In dc applications, which are the main interest of this paper, the falling resistivity-field characteristic effectively pushes the electric field off the shield terminus, where it is strongest.