In this presentation we discuss the design of a termination for a high temperature superconducting power cable with the following design: A cable conductor consisting of superconducting tapes wound onto a tight flexible tube (former) is placed inside a thermally insulating jacet (cryostat). This assembly is electrically insulated with an extruded polymer dielectric kept at room temperature. Cooling is provided by a flow of liquid nitrogen inside the former. The purpose of the termination is to connect the superconducting cable conductor at cryogenic temperature to the existing power grid at room temperature and to connect an external cooling machine at ground potential to the cable. Some of the aspects that have to be considered include the thermal insulation of the termination, the transition from superconducting tapes to a normal conductor, the current lead carrying current between high and low temperatures, the transfer of liquid nitrogen over a high voltage drop and that of providing a well defined atmosphere inside the termination and around the cable conductor. Designs based on calculations and experiments will be presented. The solutions are optimized with respect to a low heat in-leak.
I E E E Transactions on Applied Superconductivity, 1999, Vol 9(2), p. 766-769