On-line estimation of transformer model parameters

The conventional method for determining the parameters of the transformer is to performing the open and short-circuited tests. The method is only suitable for off-line application. This paper presents an alternative approach to conventional open and short-circuit test for determining the parameters of N-windings transformer operating at power frequency on an on-line mode. This approach is based on linear least errors square (LES) algorithm and uses the digitized samples of the input current and voltage as well as the output current and voltage of the transformer windings. The proposed algorithm estimates the winding parameters in two steps; while in the first step the algorithm identifying the winding parameters, in the second step, the algorithm identifying the core parameters. The proposed algorithm is applied to a two-windings transformer and simulated results are reported in this paper.