A Current Limiting Device Using Superconducting D.C. Bias Applications and Prospects

Load growth and the attendant need for interconnections for reliability of supply results in an increase in system fault levels. Solutions have to be devised to prevent the ratings of equipment such as circuit breakers being exceeded, and some of these would be expensive. An attractive solution would be the introduction of fault current limiting devices in the interconnections. This paper describes one such device employing iron cored reactors using a superconducting d.c. bias. Test results on a prototype show that this device has performance characteristics which appear to meet the demanding requirements for such devices. These characteristics, the economics and reliability of this device are discussed.