Hybrid numerical techniques for power transformer modeling: a comparative analysis validated by measurements

The paper presents alternative numerical techniques implemented in power transformer analysis and design focusing on the short circuit impedance evaluation. The proposed method adopts a particular reduced scalar potential formulation enabling a three-dimensional (3-D) magnetostatic problem solution. This method, requiring no source field calculation, in conjunction with a mixed finite-element/boundary-element technique, results in a very efficient 3-D numerical model for power transformer design office use. This model is used to develop an effective computational tool, enabling the accurate transformer characteristics prediction, thus increasing its reliability and reducing its production cost. The computed results of the proposed methodology are validated through measurements in the case of a three-phase wound core power transformer.