Structuring HVDC Cable Joints Using Smoothly Field Grading Materials

The design of accessories is critical for insuring the reliability of HVDC accessories even more as ever high voltages are targeted. Different technologies are available today that do not necessarily involve the interposition of a field grading layer between the cable insulation and the joint body. In this work, we explore the solution of setting a two-layers joint body with the idea of keeping the same polymer and using fillers to impart non-linearity to the conductivity. We show that significant reduction of field maxima can be reached with this design. The so constructed fictive material appears feasible considering literature data. Whether full objects can be produced is another question.