Estimation of a Disk Transformer Winding's Ladder Network Parameters Using Analytical, FEM, and Terminal Measurements

The paper presents a variety of methods for estimating the impedance parameters of a ladder network of a transformer disk winding. These methods depend on whether transformer design details are available or whether the parameters have to be estimated directly based on measurements. These methodologies include analytical, Finite Element (FEM), and terminal-based measurements combined with optimization techniques. In the case of a transformer whose geometric details are known, the analytical formulas presented can be employed to quickly determine the ladder network parameters. By using electromagnetic field simulations using FEM, the parameters of the transformer winding can be estimated more precisely and accurately. The geometry of a transformer is not readily available, however, so a methodology is provided for estimating the parameters using measured input-output values at the winding terminals. This paper presents simulations and experimental results for an eight-disk transformer winding, and the methods are validated by comparing the calculated parameters.