New method of the transmission line protection

This paper presents the new method of transmission line protection based on modeling of the line´s ABCD constants. The method is based on a comparison between the actual values of current and/or voltage at the sending end of the protected section of a line and the same values calculated by means of current and voltage parameters at the receiving end of the protected section provided that there are no faults in this section. The relationships between the currents and the voltages at the two ends of the protected line may be expressed through the line´s ABCD constants. The new mode of protection based on modeling the line with ABCD constants is applicable to long and transmission lines.