UNTRANSPOSED TRANSMISSION LINE PARAMETER ESTIMATION WITH FULLY DISTRIBUTED PARAMETER MODEL USING SYNCHRONIZED/UNSYNCHRONIZED MEASUREMENTS

Accurate transmission line parameter estimation is essential for best performances of many applications in practical power systems. This paper proposes a parameter estimation method for untransposed transmission lines in phasor domain using synchronized or unsynchronized phasor voltage and current measurements at dual terminals of the line. The line is represented with fully distributed parameter model in phasor domain, with full consideration of line asymmetry of untransposed lines. The line model includes not only unknown transmission line parameters, but also synchronization angle between the measurements at both terminals of the line, to ensure that the algorithm could work even with unsynchronized measurements. Afterwards, the line parameters as well as the synchronization angle are obtained by solving the line model using state estimation. Numerical experiments in PSCAD/EMTDC verify the estimation accuracy of the proposed method.