Uncertainty in Transmission Line Parameters: Estimation and Impact on Line Current Differential Protection

This paper presents a method to estimate the transmission line parameters using synchrophasor measurements from phasor measurement units (PMUs), as well as hybrid measurements from PMU and supervisory control and data acquisition system. It also proposes a method to estimate transmission line parameter uncertainties considering the measurement inaccuracies. Transmission line protection is important for secure and reliable operation of the power system. With the advent of the synchrophasor technology and advances in the communication system, current differential relays can be implemented as a reliable protection system for the transmission lines. In this paper, a new current differential protection scheme has been suggested for transmission line protection using synchronized measurements. The effect of parameter uncertainty on the protection scheme is also investigated.