Multi-calibration of channel error for measuring apparatus of power transmission line parameters

The impedance measurement error caused by the phase measurement error in a measuring apparatus of power frequency parameters for power transmission line is analyzed. A piecewise linearization data fitting method based on least square principle is used to set the relation function between measuring value and real value,which is then applied to calibrate the channel error in a new multi-calibration method,namely,amplitude calibration,phase calibration and amplitude-phase relation calibration method. It is simple in principle and better in effectiveness,and can be applied to site measuring.