The increase of line protection's sensitivity to diphasic dead shorts behind the transformers of branches

Abstract

The following algorithm of action of measuring body of reserve protection is offered: continuously differences vectors currents of phases A and B, B and C, C and A in these and previous timepoints are defined, these differences are subtracted the friend from the friend, and then - and their differences. It is shown that it provides the demanded sensitivity to two-phase short zamykakniya behind low-power transformers branch. The blocking ensuring the correct functioning of protection in various modes are considered. The algorithm of logical part is presented. Difficulties of realization on static elements are noted and at bilateral food.

Keywords

• the line with branches
• short circuits
• protection
• sensitivity
• a difference of currents