Journal of Electrical and Electronic Engineering 2014; 2(1): 28-35 Published online March 30, 2014 (http://www.sciencepublishinggroup.com/j/jeee) doi: 10.11648/j.jeee.20140201.15 Development of MATLAB-based software for the design of the magnetic circuit of three-phase power transformer Obinwa Christian Amaefule 1 , Afolayan Jimoh Jacob 2 , Akaninyene Bernard Obot 2 1 Department of Electrical Engineering, Imo State University (IMSU), Owerri, Nigeria 2 Department of Electrical/Electronic and Computer Engineering, University of Uyo, AkwaIbom, Nigeria Email address: littlekrix222@yahoo.com (O. C. Amaefule), afolayan.jimoh@yahoo.com (A. J. Jacob), akanobot2005@yahoo.co.uk (A. B. Obot) To cite this article: Obinwa Christian Amaefule, Afolayan Jimoh Jacob, Akaninyene Bernard Obot. Development of MATLAB-Based Software for the Design of the Magnetic Circuit of Three-Phase Power Transformer. Journal of Electrical and Electronic Engineering. Vol. 2, No. 1, 2014, pp. 28-35. doi: 10.11648/j.jeee.20140201.15 Abstract: Essentially, transformers consist of two electrical conductors called the primary winding and the secondary winding which are coupled magnetically together by a magnetic circuit. Transformers work based on the principle that energy can be efficiently transferred by magnetic induction from one winding to another winding by a varying magnetic field produced by alternating current. The magnetic circuit or core of a transformer is designed to provide a path for magnetic field, which is necessary for induction of voltages between the windings. In this paper, MATLAB-based software was developed for automatic computation of the magnetic circuit parameters of a three phase power transformer once the input specifications are supplied. A sample design problem was used to demonstrate the effectiveness of the program. Apart from its flexibility and speed, the program removed the drudgery involved in the design. In addition, the MATLAB-based software presented in this paper will serve as a useful teaching and laboratory tool for undergraduate courses in transformer design. Keywords: Transformer, Magnetic Circuit, Power Transformer, Three Phase, Single Phase, MATLAB 1. Introduction A transformer is an electrical device that transfers energy from one electrical circuit to another purely by magnetic coupling. Essentially, transformers consist of two electrical conductors called the primary winding and the secondary winding which are coupled magnetically together by a magnetic circuit. A transformer works based on the principle that energy can be efficiently transferred by magnetic induction from one winding to another winding by a varying magnetic field produced by alternating current. The magnetic circuit or core of a transformer is designed to provide a path for the magnetic field, which is necessary for induction of voltages between the windings. A path of low reluctance (that is, low resistance to magnetic lines of force), is normally used for this purpose. In addition to providing a low reluctance path for the magnetic field, the core is designed to prevent the circulation of electric currents within the core. Such circulating currents, called eddy currents cause heating and energy loss in the transformer. In addition, in transformer design, engineers must ensure that compatibility with the imposed design specifications is met, while keeping manufacturing costs low [1, 2]. Consequently, the complexity of transformer design demands reliable and rigorous solution methods. ). In view of the challenges, a user-friendly and effective way for calculating the magnetic circuit parameters of power transformers through the use of software is seriously required. Given that MATLAB is one of the most popular mathematical programs used in engineering analysis, in this paper a MATLAB–based software tool will be developed for the design of the magnetic circuits of power transformers. In this case, the software tool will make use of the MATLAB Application Program Interface (API) to extend the functionalities of MATLAB application to include the design of the magnetic circuit of power transformers. Specifically, this paper presents the design of the magnetic circuit of power transformers using MATLAB–based software presented in this paper. Sample design problem is used to demonstrate the effectiveness of the software solution. 2. Review of Related Works A transformer has been defined by ANSI/IEEE [3] as a static electric device consisting of a winding, or two or more