Single-Phase and Three-Phase Transformers

In this chapter, the single-phase and three-phase ideal and real transformers and autotransformers are studied. Herein, the equivalent and approximate equivalent circuits of a real transformer are presented, and their parameters are determined by using the open-circuit and short-circuit tests. Moreover, the voltage regulation of a real transformer is formulated and studied. In addition, the maximum efficiency of a real transformer along with its daily efficiency for a variable load is studied. The various configurations of a three-phase transformer, the phase shift of three-phase transformers, and per-phase analysis of balanced three-phase power systems including three-phase transformers are the next sections of the chapter.