Economical Design of a 3-Phase Transformer

A method of preliminary design of a 3-phase core transformer is offered, giving lowest priced transformer conforming to performance requirements of core loss, copper loss, per cent impedance and no-load current. A flat minimum of the resulting price function allows further refinements of the design. The only empirical values used in the procedure are the insulation clearances and coil thicknesses given by Figure 2. Technological improvements are introduced in the design by corresponding corrections of the charts of Figure 2.