An Impedance Parameters Online Measuring Method of Asymmetric Transmission Lines

Considering that the online measurements of transmission line parameters at present don't fit the asymmetric transmission line, this paper presents a new impedance parameters online measuring method. In this method, the synchronous measurement data of the terminal voltages and currents were tested and processed with the least square method. Then the asymmetric three-phase line parameter calculating formulas were derived based on the asymmetric three-phase transmission lines impedance parameters model. The simulation results verified the validity and accuracy of this method, which can be expected to be a theory basis for the on-line measurement of the transmission line parameters.