SOLID-STATE CURRENT LIMITER FOR POWER DISTRIBUTION-SYSTEM

To prevent voltage decrease of distribution systems, the principle and fundamental characteristics of a solid-state current limiter using GT O thyristors were investigated. Basic components of the apparatus were a fast solid-state switch and a current limiting impedance of low res istance in parallel with the switch. Experimental results of the test current limiter showed the fault current was limited successfully, reg ardless of DC component size. The time from detection of fault occurre nce to interruption of the fault current by the solid-state switch was 40 mus. This time was very short in comparison with that before the f ault current reached a large value. Thermal rise of the solid-state sw itch for conduction was solved by a self-cooling apparatus using a non -combustible cooling liquid. The results indicated that the solid-stat e current limiter was a valuable protecting device for high fault curr ent distribution systems.