Study on the influence of unsymmetrical modes on power transformer efficiency

Abstract

It is known that electric power systems cannot be imagined without transformers. Among electrical devices, the transformer is a device with high efficiency when working based on nominal indicators. However, malfunctions are occurring due to various quality indicators of electricity in electric power networks. As a result, it prevents the supply of high-quality and continuous electricity to consumers. In this article, the evaluation of efficiency due to voltage asymmetry in transformers is developed. Matlab/Simulink software was used to observe the voltage asymmetry. A 160kVA transformer was assembled in the model. Its primary data was taken from the manufacturer's manual. The greatest effect of voltage asymmetry on the efficiency of the transformer was observed at the optimal value of the load, 80%. In this case, due to asymmetry, the efficiency decreases by 0.1%. The change in transformer efficiency was evaluated at positive and negative values of the voltage deviation. In this case, when the voltage in the network changes by ±6%, a decrease in the efficiency of the transformer by 0.1% was observed.