Evaluation of HVDC cables for the St. Lawrence river crossing of Hydro-Quebec's 500 kV DC line. III. Thermal behaviour

摘要

For pt.II see ibid., p.110-16 (1991). The thermal analyses conducted during the different stages of Hydro-Quebec's St. Lawrence river crossing project are presented. The important impact of the thermal studies on the choice of cable is described, and the design of the installation is presented. The numerous problems faced during the cable prototype are detailed, and demonstration tests and the solutions obtained by numerical analysis using the finite-element method are addressed. These problems were related in part to the temperature controls for the cable and its accessories, and in particular to the control of the temperature gradient across the dielectric material at various locations along the test loop.