ABSTRACT
This chapter describes a method that use only the two-winding leakage inductances to model the transformer and explores how it lends itself naturally to matrix methods to obtain complicated connections among the windings on the same or different legs. It briefly introduces some background material on two-winding leakage inductances for later reference and to establish notation. In general, a multiterminal transformer with n windings may have less than n - 1 secondary terminals. The zig-zag connection is often used for grounding purposes. It affords a low impedance to zero-sequence currents. The zig-zag connection involves interconnecting two secondary windings from different phases. Regulation effects can be obtained by comparing the output terminal voltages with the no-load terminal voltages. The ungrounded Y connection can be generalized to include Y connections with an impedance connecting the neutral point to ground.
