Parameter estimation of three-winding transformers using genetic algorithm

The paper presents an in situ parameter estimation method to determine the equivalent circuit parameters of the three-winding transformer (TWT). The suggested method also estimates geometrically a complex parameter that is mutual leakage between secondary and tertiary windings, which would be useful in transient studies. Beside the saturation effect of the transformer is taken into account by estimating a highly nonlinear parameter that is magnetizing circuit reactance. Different search based optimization tools are applied for parameter estimation among which the results obtained using genetic algorithm is found to be encouraging. Load test data at one particular operating point namely supply voltage, load currents, input power, and load impedance is sufficient to estimate the parameters. The results are experimentally validated against the directly measured performance of TWT. The method is applicable for performance determination, power system load flow studies and design of protection circuits of the TWT. (C) 2003 Elsevier Science Ltd. All rights reserved.