Novel Zero-Sequence Blocking Transformer (ZSBT) Using Three Single-Phase Transformers

• Published in: IEEE transactions on energy conversion Vol. 28; no. 1; pp. 234 - 242
• Main Authors: Laka, A., Barrena, J. A., Chivite-Zabalza, J., Vidal, M. A. R., Calvo, G.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-03-2013; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AC-DC power converters; blocking transformer; Cables; Circuit faults; Computer simulation; Core loss; Impedance; Inductance; Inductors; Magnetic cores; magnetic flux; Magnetic saturation; Phase transformers; power harmonic filters; Saturation (magnetic); Saturation magnetization; Studies; Transformers; Winding; Windings; zero sequence
• ISSN: 0885-8969; 1558-0059
• DOI: 10.1109/TEC.2012.2229282

Zero-sequence blocking transformers (ZSBTs), used to block the zero-sequence components that are present in a three-phase system, are commonly built winding the three phases around the same core limb. They are difficult to construct, especially in high-power applications that use large cross-sectional cables, as they require a symmetrical winding distribution for not to produce any flux for positive- and negative-sequence components. This paper presents a novel ZSBT configuration using three single-phase transformers. Although slightly greater in size, they can be easily wound, even when thick cables are used. Moreover, the proposed topology can be used as a simulation model of any ZSBT configuration, where core losses and magnetic saturation of the core are included by connecting a single inductor to the secondary windings of the transformers. This paper provides full details of the circuit and is supported by simulation and experimental results of the proposed ZSBT.