A new modeling of Matlab transformer for accurate simulation of ferroresonance

The main aim of this paper is to present a new modelling of transformers in Simulink/Matlab enabling to simulate slow transients more accurate than the existing models used in the software. In this paper, first several types of transformer cores and their magnetic behaviors are described. Next, for accurate simulation of slow transients, extended transformer models based on duality principle of magnetic circuits is introduced. Then, two conventional three- and five-legged core transformers are simulated in Simulink/Matlab and in order to verify accuracy of models, simulation results are compared with those obtained from measurements. Finally, ferroresonance simulations are examined by both the proposed models and existing transformer models in Matlab/Simulink. The comparison clearly shows inability of existing transformer models to study slow transients for transformers.