DEVELOPMENT OF A HIGH-SPEED SWITCHING-SYSTEM FOR DISTRIBUTION NETWORKS

This paper describes a high-speed switching system for distribution ne tworks which has been developed with the aim of improving power supply reliability (reducing the number of supply interruptions) of distribu tion systems, When a fault occurs in conventional distribution systems , the fault section is isolated using a sequential time-out control sc heme which requires the reclosing and re-reclosing of the entire syste m. A major drawback of such systems is that normal sections are also s ubjected to unnecessary power supply interruptions. In order to resolv e this problem, we have developed a high-speed switching system which isolates only the fault section without interrupting the power supply to normal sections. This new system can fully restore power to the nor mal sections and completely isolate the fault section within 500 ms in the case of a ground fault.