The Introduction of Transformers

The introduction of transformers into analysis tools for three-phase electrical systems may be unlikely because of the large number of transformers in the network, the variety of connections, and the forms of representation. Thus, the impact of the various transformers in the study of the systems of distribution of electric energy is significant, since they affect the losses in the system, the methods of grounding, the strategies of protection, etc.

Due to the great importance of three-phase transformers models in computational analysis, increasingly requiring the development of new tools for the study of electrical distribution systems, a motivation is born for the development of more comprehensive models of transformers.

Many examples of components of the distribution systems are limited to the analysis of three-phase balanced systems and these models are made assuming that the three-phase system operates under equilibrium conditions and thus adopts a single-phase modeling for the problem. Evaluating the equivalent single-phase circuit in the analysis, many studies have presented power flow solution algorithms as well as component models of electrical systems.

However, for electricity distribution systems, the simplification followed is not sufficient for their correct evaluation, because these systems are generally well unbalanced, due to the different loads connected to the phases, the asymmetry of the lines without transposition and the existence of single-phase circuits , two-phase and three-phase.