Analysis of the influence of the level of signal distortion on current error and phase displacement of the inductive current transformers

The aim of the paper is to present results concerning the influence of conductive disturbances on accuracy of transformation of distorted signal main harmonic through the inductive current transformers (CTs). Analysis of the results from the laboratory studies shows, that conductive disturbances in the CT primary current, in some measuring conditions, cause decrease of the accuracy of transformation of the main harmonic of distorted current. Determine of the current error and additionally phase displacement of the inductive CT for main harmonic of the transformed distorted current enables with the previously estimated value of the composite error calculation of the maximal changes in values of selected factors e.g. THDI used for characterization of the power quality caused by the usage of tested CT in indirect measuring system.