Author(s)

Jandecy Cabral Leite¹, Manoel Socorro Santos Azevedo¹, Ubiratan Holanda Bezerra², Ignacio Pérez Abril³, Carlos Alberto de León Benítez³

¹Department of Electrical and Industrial Engineering, Institute of Technology and Education Galileo of Amazonia (ITEGAM), Manaus, Brazil.
²Department of Electrical Engineering, Federal University of Para, Belém, Brazil.
³Department of Electrical Engineering, Central University of Las Villas (UCLV), Santa Clara, Cuba.

The electric networks for the distribution to low voltage costumers can be configured in different layouts. Two main approaches are used: the European system composed by three-phase distribution transformers or the North American system composed by single-phase distribution transformers and three-phase transformer banks of single-phase transformers. With respect to harmonic analysis, much more attention has been focused on the three-phase balanced systems arrangements than on the unbalanced four-wire delta system extensively used to supply low voltage loads of 120/240 V. Different authors have shown the three-phase power systems modeling on a phase-coordinates frame. However, the presence of significant asymmetries in the network forces the need of adding a new phase-coordinates model to represent the three-phase transformers banks of two or three single-phase transformers in its various connections. Several papers treat the use of harmonic analysis programs based on a phase-coordinates frame to study the Wye or Delta connected three-phase systems. However, the commonly used four-wire delta connected systems are not fully treated in literature. This paper presents a phase-coordinates model for the representation of the commonly used three-phase transformer banks of three or two single-phase transformers, and single-phase distribution transformers for the harmonic analysis of the four-wire delta connected systems. The harmonic analysis method based on the presented model is used to examine the characteristics of this kind of distribution system with respect to the penetration of harmonics currents from loads to the primary system.

Harmonic Analysis, Phase-Coordinates, Four-Wire Delta Systems

Leite, J. , Azevedo, M. , Bezerra, U. , Abril, I. and de León Benítez, C. (2016) Harmonic Propagation from the Low Voltage Four-Wire Delta Systems. Journal of Power and Energy Engineering, 4, 1-19. doi: 10.4236/jpee.2016.412001.