Using Dual Circuits to Simulate Electromagnetic Processes in Cascade Station Service Voltage Transformers

—The scientific and methodological principles of development of the design models of a new device—station service voltage transformers intended for use in design study—are considered. The proposed models relate to the “white box” model class, which provide the maximum accuracy when solving such problems. The models are based on equivalent circuits of active parts, which are obtained using the principle of duality of magnetic and electric circuits. It is revealed that the determination of parameters and verification of models are possible only at the manufacturing plant of transformers. Special attention is paid to reproduction in the models of magnetizing process of transformer. The experimental oscillograms are given of magnetizing currents of magnetic conductors of the active parts and of the transformers as an assembly, which show the capacitances of high-voltage winding have a great effect on the open-circuit current. The algorithm for determination of the parameters of transformer model for calculation of steady state conditions is presented, which provides a good coincidence with experimental values for integral parameters, such as the power loss and the root-mean-square value of magnetizing current.