Adaptive protection of short circuits in transmission lines

This paper proposes an adaptive protection scheme which has been developed through the analysis of short circuits in transmission lines. The method assumes a different protection pattern depending upon the distance between the fault position and the location of any protection devices. An adaptive threshold dependent upon the load on the system is used for initiation of the over-current protection routines. The adaptive quick-break current protection adopts a different threshold current according to the system mode and the type of short circuit. It is shown that the selectivity and reliability of the power system can be ensured, and sensitivity improved.