Denoising of PMU Measurements for Accurate Calculation of Transmission Line Parameters

Power system transmission line parameters are essential in monitoring and control applications. More specifically, the values of the transmission line parameters are used in state estimation, contingency analysis, and as settings in protection relays. However, the stored transmission line parameters in the control center database often deviate from their actual values, impacting negatively the applications of the power system control center. The use of PMU (Phasor Measurement Unit) measurements is the most convenient and simple way for refining the parameters of the transmission line; however, the contamination of the PMU measurements with noise from the instrument transformers and the communication channels could sometimes deteriorate the accuracy of the calculated parameters. In this paper, the denoising of the PMU measurements using wavelets is proposed prior to the calculation of the transmission line parameters. The proposed approach is used for calculating the transmission line parameters of the IEEE 14-bus system and the results are extensively discussed.