INTRODUCTION

In electrical engineering, it is often useful to use an equivalent circuit model to describe the non-ideal operation of a device such as a transformer. While an ideal model may be well suited for rough approximations, the non-ideal parameters are needed for careful transformer circuit designs. Knowing the non-ideal parameters allows the engineer to optimize a design using equations rather than inefficiently spending time testing physical implementations in the lab.

If all dimensions and material properties of a transformer are known, the non-ideal parameters can be directly calculated. However, this is usually not the case, and a simple technique for obtaining the parameters can be used. A method for determining the parameters of the equivalent circuit model using two simple tests is described. Expressions for calculating the parameters are derived in terms of laboratory measurements. The procedure is performed in the lab for a transformer. As an example of the usefulness of the non-ideal equivalent circuit, the parameters found in the lab are used to calculate one important transformer characteristic, maximum efficiency.