Measurement of transmission line parameters from SCADA data

Transmission line equivalent circuit parameters are often 25% to 30% in error compared to values measured by the SCADA system. These errors cause the economic dispatch to be wrong, and lead to increased costs or incorrect billing. The parameter errors also affect contingency analysis, short circuit analysis, distance relaying, machine stability calculations, transmission planning, and state estimator analysis. An economic example is used to demonstrate the affect of transmission line errors. SCADA measurements from several utilities are used to compute the ´real world´ value of the transmission line parameters. State estimation with the estimated parameters is compared to the computations using the theoretical values.