Current-Transformer Output and Application Charts

The performance of a multiratio current transformer is most simply represented as a function among the admittance vector locus of the core for one turn, the secondary-turn number N, and the secondary impedance Z. If the ratio of N²/Z is used as a variable, extremely simple application charts for ratio correction factor in relation to primary currents result. The ratio N²/Z furthermore is basic in the matching of transformers and burdens for maximum volt-ampere output at given primary current. Methods for computing the optimum volt-ampere output are given, and a chart is derived from which all data for a correct matching can be obtained at once. The usefulness of these methods is explained in connection with various examples such as applied to relaying circuits commonly used.