Operation control of internally conductor cooled cable system

The development of 275 kV internally-conductor-cooled cable systems is under way for application to long-distance large-capacity (1500 MVA/cct) underground transmission systems. From the viewpoint of the reliability and the energy economy of these systems, the operational control system for the cooling facilities is especially important, because the facilities require large cooling capacity due to the large heat loss of the cable conductor. The cooling device characteristics are described, and the effects of operation control on energy savings are examined. A long-term field test has shown that the computer-controlled operation system is very useful. Simulation results for the operational control system confirm that calculated values are in good agreement with measurement results