IJIRST –International Journal for Innovative Research in Science & Technology| Volume 2 | Issue 02 | July 2015 ISSN (online): 2349-6010 All rights reserved by www.ijirst.org 313 Transformer Testing and Analysis using MATLAB/Simuink Nileema Patil Prof. J. H. Patil PG Student Professor Department of Electronics and Tele Communication Department of Electronics and Tele Communication D. N. Patel college Of Engineering, Engineering Shahada, Nandurbar, India D. N. Patel college Of Engineering, Engineering Shahada, Nandurbar, India Abstract The Transformers working is 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, we have a MATLAB-program that utilizes a Graphical User Interface (GUI) to calculate the circuit parameters and efficiency of single phase ac transformer. This project has been designed and developed by using MATLAB & SIMULINK for developing the graphical user interface (GUI) of AC transformer. This GUI could be used in the form of simulation for an electrical software application in laboratory session. It is also can be used as e-learning of teaching and learning process in terms on how to analyses practically through the software. This paper has presented a virtual instrument (VI) of AC transformer by using MATLAB & SIMULINK which it is a user-friendly programming language and easy to be learnt by new programmer. It practices the user-friendly application which the user just needs to give a desired data for processing stage and output performance result. This paper consisted of three sections which are single phase transformer, Transformer Tests and Performance, Performance (Z_1, Z_2, R_c, X_m), Performance (Z_{eq}, R_c, X_m) These analyses focused on the performance of the AC transformer and other aspect Lagging, Leading, Efficiency, Performance Graph & analysis. The MATLAB & SIMULINK result have been verified and compared with manual calculation in order to ensure they are correct and reliable. Keywords: MATLAB, Transformer, GUI, Analysis, power factor, etc. _______________________________________________________________________________________________________ I. INTRODUCTION The transformer is a valuable apparatus in electrical power systems, for it enables us to utilize different voltage levels across the system for the most economical value. A transformer is a static device that transfers energy from one electrical circuit to another purely by magnetic coupling. The purpose of a transformer is to change electrical voltage to a different value. Essentially, a transformer consists of two or more windings coupled by mutual magnetic flux. If one of these windings, the primary, is connected to an alternating-voltage source, an alternating flux will be produced whose amplitude will depend on the primary voltage, the frequency of the applied voltage, and the number of turns. A portion of this flux, referred to as mutual flux, will link a second winding of transformer. The input winding to a transformer is called the primary winding. The output winding is called the secondary winding. If there are more turns of wire on the primary than on the secondary, the output voltage will be lower than the input voltage. For a step- down and a step-up transformer. Notice that the winding with the greater number of turns has the higher voltage. one winding has twice as many turns as the other. In one case the voltage is stepped down to half, while in the other the voltage is stepped up to double. It is important to know the ratio of the number of turns of wire on the primary winding as compared to the secondary winding. This is called the turns ratio of the transformer. Transformers can be modeled as either ideal transformers or actual transformers. In the case of ideal transformer, many assumptions have to be considered. Some of these assumptions are the magnetic material is infinitely permeable and does not saturate, negligible core loss, all flux is confined within the magnetic core and each winding has no resistance. While in the case of actual transformer, these assumptions are no longer applicable. II. REVIEW OF RELATED WORK A transformer has been defined by ANSI/IEEE [3] as a static electric device consisting of a winding, or two or more coupled windings, with or without a magnetic core, for introducing mutual coupling between electric circuits [2]. Transformers operation depends on electromagnetic induction between two stationary coils (the electric circuit)and a magnetic flux of changing magnitude and polarity (the magnetic circuit). In practice, transformers transform electrical energy into magnetic energy, and then back into electrical energy. Given its importance, transformer design is a big business in the electric power industry.