Measurement of Equivalent-Circuit Parameters for Single-Phase Transformers with Unknown Turns-Ratio and Large Series-Branch Impedances

This paper describes a simple method for the determination of turns-ratio and equivalent-circuit parameters of single-phase transformers with large series-branch impedances. Based on test results, phasor diagrams are drawn which give formulas for the turns-ratio and equivalent circuit parameters with series-branch impedance split into low- and high-voltage components