Estimation of Design Parameters of Single-Phase Distribution Transformers from Terminal Measurements

In this paper a novel method is proposed for the estimation of the design parameters of single-phase distribution transformers us-ing data acquired from terminal measurements along with name-plate data and external tank dimensions. Transformer parame-ters that can be measured from terminals, e.g. leakage induct-ance, saturation inductance, winding resistance, are considered first. These parameters are analytically correlated with the geometrical information of the transformer structure. A system of non-linear equations is derived accordingly. Winding dimensions and the number of turns are computed with acceptable engineer-ing accuracy. The core dimensions (including its cross sectional area) are calculated using winding information. The obtained data can be utilized to develop white- or gray-box models to be used in the investigation of the thermal and/or electromagnetic behavior of power transformers as presented in several research studies published to date. Examples on laboratory and utility-grade transformers are shown for illustration and validation of the proposed design parameter estimation method.