Linear, lumped parameter transformer model reduction technique

• Published in: IEEE transactions on power delivery 1995-04, Vol.10 (2), p.853-861
• Main Authors: Gutierrez, M., Degeneff, R.C., McKenny, P.J., Schneider, J.M.
• Format: Article
• Language: English
• Subjects: Design engineering; Distributed computing; Power engineering and energy; Power system modeling; Power system reliability; Power system transients; Power transformer insulation; Power transformers; Reduced order systems; Reliability engineering
• ISSN: 0885-8977; 1937-4208
• DOI: 10.1109/61.400845

The behavior of large power transformers under transient conditions is of significant interest to both transformer designers and power system engineers. The designer employs computer programs to construct detailed electrical models enabling him to compute the transformer's internal transient voltage distribution. Using this information, and various other tools, the design engineer can develop a reliable and cost effective insulation structure. The power engineer requires a reduced model that accurately represents the transformer's behavior to investigate the effects of power system transients. Reduced models are generally obtained either from detailed design models, or from measurements on fully constructed transformers. The latter technique has the major disadvantage that in the absence of an expensive prototype design, improvements cannot be made. Presently, both methods are subject to varying degrees of error. This paper presents a reduction technique that starts with the linear, detailed design model, and provides a reduced model of any specified size, while retaining the same computational accuracy as the original model. The method is mathematically exact, relatively straight-forward and compatible with time domain transient analysis programs. Application of the technique to the detailed model of a 765/345/34.5 kV, 500 MVA single phase autotransformer is provided.< >