Power Transformer No-Load Loss Prediction with FEM Modeling and Building Factor Optimization
- 1
- 2
- 3
- 4
Abstract
Estimation of power transformer no-load loss is a critical issue in the design of distribution transformers. Any deviation in estimation of the core losses during the design stage can lead to a financial penalty for the transformer manufacturer. In this paper an effective and novel method is proposed to determine all components of the iron core losses applying a combination of the empirical and numerical techniques. In this method at the first stage all computable components of the core losses are calculated, using Finite Element Method (FEM) modeling and analysis of the transformer iron core. This method takes into account magnetic sheets anisotropy, joint losses and stacking holes. Next, a Quadratic Programming (QP) optimization technique is employed to estimate the incomputable components of the core losses. This method provides a chance for improvement of the core loss estimation over the time when more measured data become available. The optimization process handles the singular deviations caused by different manufacturing machineries and labor during the transformer manufacturing and overhaul process. Therefore, application of this method enables different companies to obtain different results for the same designs and materials employed, using their historical data. Effectiveness of this method is verified by inspection of 54 full size distribution transformer measurement data.
- G. F. Mechler and R. S. Girgis, “Calculation of Spatial Loss Distribution in Stacked Power and Distribution Transformer Cores,” IEEE Transactions on Power Delivery, Vol. 13, No. 2, 1998, pp. 532-537. doi:10.1109/61.660925
- P. S. Georgilakis, “Spotlight on Modern Transformer Design,” Springer-Verlag, New York, 2009. doi:10.1007/978-1-84882-667-0
- NEMA Standard TP 1, Guide for Determining Energy Efficiency for Distribution Transformers, 2002.
- CENELEC Standards HD 428.1, Three Phase Oil-immersed Distribution Transformers 50 Hz, from 50 kVA to 2500 kVA, with Highest Voltage for Equipment Not Exceeding 36 kV, 1992.
- A. J. Moses, “Prediction of Core Losses of Three Phase Transformers from Estimation of the components Contributing to the Building Factor,” Journal of Magnetism and Magnetic Materials, Vol. 254-255, 2003, pp. 615- 617. doi:10.1016/S0304-8853(02)00911-3
- A. Basak and, A. A. Bonyar, “Effects of transformer core assembly on building factors,” Journal of Magnetism and Magnetic Materials, Vol. 112, No. 1-3, 1992, pp. 406- 408. doi:10.1016/0304-8853(92)91214-E
- K. A. L. Abdul-Retha and A. Basak, “A Comparison of Building Factors for Different Types of Transformer Cores Built With Highly Oriented and Conventional Grade Silicon-Iron Laminations,” Journal of Magnetism and Magnetic Materials, Vol. 26, No. 1-3, 1982, pp. 92- 94. doi:10.1016/0304-8853(82)90123-8
- Z. Valkovic, “Additional Losses in Three-Phase Transformer Cores,” Journal of Magnetism and Magnetic Materials, Vol. 41, No. 1-3, 1984, pp. 424-426. doi:10.1016/0304-8853(84)90237-3
- G. W. Swift, “Excitation current and Power Loss Characteristics for Mitered Joint Power Transformer Cores,” IEEE Transactions on Magnetic, Vol. 11, No. 1, 1975, pp. 61-64. doi:10.1109/TMAG.1975.1058541
- M. Elleuch and M. Poloujadoff, “New Transformer Model Including Joint Air Gaps and Lamination Anisotropy,” IEEE Transactions on Magnetic, Vol. 34, No. 5, 1998, pp. 3701-3711. doi:10.1109/20.718532
- M. Elleuch, M. Poloujadoff, “Analytical model of iron losses in power transformers,” IEEE Transactions on Magnetic, Vol. 39, No. 2, 2003, pp. 973-980. doi:10.1109/TMAG.2003.808591
- C. Nussbaum, T. Booth, A. Ilo and H. Pfutzner, “A Neural Network for the Prediction of Performance Parameters of Transformer Cores,” Journal of Magnetism and Magnetic Materials, Vol. 160, No. 1, 1996, pp. 81-83. doi:10.1016/0304-8853(96)00122-9