Calibration and Leakage Impedance Measurements of a Standard 1:2 Ratio Autotransformer Inductive Voltage Divider

A method and circuit for determination of the ratio error of an inductive autotransformer voltage divider having a 1:2 nominal ratio are shown in this paper. The circuit is used for measurement of a differential voltage between corresponding taps of the divider investigated and reference inductive divider based on which ratio error is determined. The distinguishing feature of the measuring method developed is the possibility of virtual reconstruction of the rated ratio value of a standard divider. Thus, during the measurement process, there is no need to use the standard divider; instead, a divider having the constant, unknown error is used. The proposed circuit can also measure the leakage impedance of divider windings when using the developed three-stage procedure of measurement. In this paper, the obtained measurement results of the ratio errors and winding leakage impedance for different divider load and in a wide frequency range are presented.