Leakage reactance is one of the most important specifications in transformer that has significant impact on its overall design. Variation in leakage reactance serves as a diagnostic measure to indicate mechanical integrity of power transformers before and after a short circuit test that demonstrates mechanical strength of transformer windings. This paper presents an approach for leakage reactance computation through finite element method (FEM) and subsequent analysis of winding deformation due to a short circuit. A concentric two winding transformer is considered and reactance computation is made using FEM package. The results of computation are compared against classical method. It is observed that the method can provide sufficient theoretical basis for improving the design.

1. R. P. P. Smeets, L. H. Te Paske. (2006). An update test experiences with short circuit withstand capability of large power transformers. Trafotech. III-31-38.
2. K. Karsai, D. Kerenyi and L. Kiss. (1987). Large power transformers. Elsevier Science Publishers.
3. Pavlos S. Georgilakis. (2009). Spotlight on modern transformer design. Springer, London.
4. G. B. Kumbhar, S. V. Kulkarni. 2007. Analysis of short circuit performance of split winding transformer using coupled field circuit approach. IEEE Transactions on Power Delivery. vol. 19. No. 1. 214-220.
5. Yu-Sheng Quan, Jiang Shan, Li Wei (2011). Research on the deformation of transformer windings based on the analysis of short circuit reactance. IEEE conference on Power Engineering and Automation Conference (PEAM). vol. 2. 8-9 Sep 2011, Wuhan, China. 240-243.
6. S. Santhi, V. Jayashankar 2006. Continual assessment of winding deformation during a short circuit test. Transactions of IEE Japan. PE. vol. 126. No. 7. 712-713.
7. Zhiqiang Meng and Zhongdong Wang (2004). The analysis of mechanical strength of HV winding using finite element method, part 1 calculation of electromagnetic forces. 39th International universities power engineering conference, UPEC-2004. Bristol, UK, 6-8 Sep 2004. 170-174.
8. M. Allahbakshi, K. Abbaszadeh, A. Akbari (2005). Effect of asymmetrical dimensions in short circuit forces of power transformers. Proceedings of eighth International conference on Electrical Machines and systems, ICEMS-2005. 27-29 Sep 2005, Nanjing. 1746-1749.
9. Huyn-Mo Ahn, Yeon-Ho Oh, Joong-Kyoung Kin, Jae-Sung Song and Sung-Chin Hahn (2012). Experimental verification and finite element analysis of short circuit electromagnetic force for dry-type transformer. IEEE Transactions on Magnetics. vol. 48. No. 2. 819-822.
10. J. P. Webb, B. Forghani, D. A. Lowther. (1992). An approach to the solution of three dimensional voltage driven and multiply connected eddy current problems. IEEE Transactions on Magnetics. vol. 28. No. 2. 1193-1196.
11. B. Sollergren (1979). Calculation of short circuit forces in transformers. Electra. No. 67. 29-75.
12. S. Kulkarni, S. A. Khaparde 2004. Transformer Engineering, Design and Practice. Marcel Decker Inc. New York.

Transformer reactance Calculation fem Mechanical Strength Axial Deformation Radial Deformation.