A Useful Equivalent Circuit for a Five-Winding Transformer

It has been indicated that there is a growing interest in the possibilities of multiwinding transformers with five windings. The lack of a suitable equivalent circuit for this type of transformer has retarded some of these engineering analyses. This paper presents a practical equivalent circuit, together with a development of the necessary formulas. Numerous mathematical manipulations have been omitted in the interest of brevity. Several of these manipulations are the key to the simplicity of the final working formulas. Examples show how the various equivalent-circuit parameters are evaluated. Factors affecting the voltage regulation of a five-winding transformer are brought out with the aid of an example in which two sources of supply are present. An objective of the analysis has been to keep the equivalent circuit suitable for the calculating board. Several precautions in this connection are discussed.