Simulation of three winding power transformer in Matlab Simulink

Abstract

Background. It is difficult to analyze the energy efficiency of 110 kV electrical networks due to the lack of the possibility to conduct experiments on operating equipment, namely on power transformers. The existing methods of mathematical calculation of electrical networks do not provide a wide opportunity to study the modes of 110 kV networks. Computational experiments to analyze the energy efficiency of equipment operation reduce the risks of equipment damage and injury of maintenance personnel. Also, it allows you to explore the necessary operation modes of a 110 kV electrical network, including power transformers. Materials and methods. The transformer model is developed in the Matlab virtual laboratory using the Simpowersystem toolbox. Results. The passport data of the transformer of the type TDTN-25000/110-U1 are given. The use of a star circuit instead of a T-shaped equivalent circuit is studied since the transformer has three windings. Virtual models are developed to conduct short circuit and open circuit experiments. The calculation of the magnetization curve of the transformer core is carried out. Using a new virtual model of a transformer of the TDTN-25000/110-U1 type, the processes of short circuit and open circuit are studied. The correspondence of the simulation results and the passport data of a real transformer is presented. The oscillograms of the magnetizing current inrush are obtained. They also correspond to the real ones. Conclusions. The model error in comparison with the passport data of a real transformer does not exceed 5 %. The model is recommended to be used to analyze the energy efficiency of 110 kV electrical networks. The promising trend to research the model of a power transformer is to add the voltage regulator under load as the operation condition.