Identification of short transmission-line parameters from synchrophasor measurements

Abstract

Accurate knowledge of transmission line impedance parameters helps to improve accuracy in relay settings, post-event fault location and transmission power flow modeling. Four methods are presented in this paper to identify transmission line impedance parameters from synchronized measurements for short transmission lines. Estimates of parameters for short transmission lines is more challenging than for long transmission lines since measurement noise often causes large errors in the estimates. The effectiveness of these methods is verified through simulations. These simulations incorporate two types of measurement errors: biased and non-biased noise. The different effects of bias errors and random noise on the accuracy of the calculated impedance parameters are quantified. Last, some complicating factors and challenges inherent in real world measurements are discussed.