Research And Application On The Bus Protection In MV Or LV Power Network

According to actuality and the existing problem of the bus protection in MV or LV power system of the Baotou Iron & Steel (Group) Co., Ltd., the paper compares the disadvantage and shortcomings of bus protections in MV or LV power system and introduces a new bus protection on microcomputer and over-current-blocking , which uses the current circuit of power bay and the action contacts of feeder protection . The implementation principle, action criterions of different units, action on normal and different failure modes, measure of saturation of current transformer, applicability are presented .With superiorities in principle, speed and expansibility, it is suitable for MV or LV power system with more inlet and outlet lines. Not only the theory but also designs of software and hardware have been given to the reader. At last the application example is introduced.