Power Transformers Internal Insulation Design Improvements Using Electric Field Analysis Through Finite-Element Methods

• Published in: IEEE transactions on magnetics Vol. 44; no. 2; pp. 273 - 278
• Main Authors: Khaligh, A., Vakilian, M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Circuits; Construction; Cross-disciplinary physics: materials science; rheology; Dielectrics and electrical insulation; Electric field; Electric fields; Electric potential; Electric power generation; Exact sciences and technology; Finite element methods; finite-element analysis; Insulation; insulation design; Magnetism; Materials science; Mathematical analysis; Mathematical models; Other topics in materials science; Performance analysis; Physics; Power system modeling; power transformer; Power transformer insulation; Power transformers; Transformers; Transient analysis; Windings; Design; Finite element method; power transformer; insulation design; Analysis method; Electric field; finite-element analysis; Investigation method; Modelling; Power transformers; Electric fields; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2007.912771

Understanding the potential and electric field distribution in the insulation system of a transformer during transients is vital to its construction. Therefore, we have developed a method for electric field analysis inside a power transformer. The method consists of the following steps. (1) A lumped parameter equivalent model is constructed by dividing transformer windings into several blocks. (2) The electric circuit parameters of this model are calculated. (3) Employing the results of the transformer transient model analysis as boundary conditions, a 2-D asymmetrical electric field finite-element analysis is performed to determine electric fields through the windings. The method has been examined employing power frequency and impulse voltages. We have also demonstrated successful application of the method to a transformer and have verified the computed results by comparison with measured results.