TY - JOUR N2 - The paper presents a new method for simultaneous tracking of varying grid impedance and its uncertainty bounds. Impedance tracking consists of two stages. In the first stage, the actual noise estimate is obtained from least squares (LS) residua. In the second stage, the noise covariance matrix is approximated with the use of residual information. Then weighted least squares (WLS) method is applied in order to estimate impedance and background voltage. Finally uncertainty bounds for impedance estimation are computed. The robustness of the method has been verified using simulated signals. The proposed method has been compared to sliding LS. The results have shown, that the method performs much better than the LS for all considered cases, even in the presence of significant background voltage variations. L1 - http://www.czasopisma.pan.pl/Content/90225/PDF/Journal10178-VolumeXXI%20Issue1_10.pdf L2 - http://www.czasopisma.pan.pl/Content/90225 PY - 2014 IS - No 1 EP - 110 DO - 10.2478/mms-2014-0010 KW - power system KW - utility impedance tracking KW - uncertainty estimation A1 - Borkowski, Dariusz A1 - Barczentewicz, Szymon PB - Polish Academy of Sciences Committee on Metrology and Scientific Instrumentation DA - 2014 T1 - POWER GRID IMPEDANCE TRACKING WITH UNCERTAINTY ESTIMATION USING TWO STAGE WEIGHTED LEAST SQUARES SP - 99 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/90225 T2 - Metrology and Measurement Systems ER -