Development of 138 kV transition joint between HPPT cable and extruded cable

The authors describe the successful development of a 138 kV transition joint between high-pressure dielectric-fluid-filled cable with paper insulation and cable with extruded insulation, such as cross-linked polyethylene or ethylene propylene rubber. Such a joint must have adequate electrical and mechanical properties and contain the high-pressure dielectric fluid normally at 1400 kPa. For evaluation of the transition joint, the IEEE standard 404-1986 for laminar-to-laminar cable joints and extruded-to-extruded cable joints was considered, along with many of the specified types of tests included, such as high-voltage AC and DC, hot impulse to BIL, cyclic aging, and corona. The test results are reported