Transformer Ratio and Differential Leakage of Distributed Windings

This paper develops in as simple a manner as possible the necessity for the concept of ``differential leakage´´ where transformer action takes place between two unequally distributed windings and explains the character of differential leakage. The value to be used for the transformer ratio in the case of such unequally distributed windings is also given. All considerations are based on the conventional stepped-wave field forms, and the mathematics used involve only the simplest linear equations. While the paper is mainly intended to be expository in nature, a general indication is given at the end as to how differential leakage and transformer ratios can be calculated for both single-phase and polyphase arrangements.