Procedure for the assessment of metrological characteristics of window-type current transformers in three-phase power systems

Abstract

Window-type current transformers are widely used in medium voltage switchboards for measuring the current flowing in the cables entering the board itself. Due to their operating principle, the accuracy of such kind of current transformers may vary depending on many factors, such as, for example, the position of the cable passing through the transformer with respect to the center of the window and the proximity of the other cables. In this paper a procedure for assessing the metrological characteristics of window-type current transformers is presented and discussed along with the results of experimental tests.