Principle Research On The Micro Computer Compositive Busbar Protection For Medium Voltage System

According to actuality of the busbar protection for the mostly plant and country terminal substation in our country, a new theory for busbar protection in medium transmission or distribution power system.Aimed at the existing theory of the busbar protection , especially for busbar protection criterion in medium and low power system, this paper bring forward a new theory based on the currents of two phases. In this paper .firstly, the new busbar protection theory of medium voltage system have been introduced and summarize, the feasibility of theory also demonstrated. Some problem to Saturation of TA have discussed, and the selection criterion of TA has been educed.Not only the theory but also the programming logic diagram have been given to the reader. So it's convenience to programming for the later in future.