Research on transformer temperature distribution based on electromagnetic loss characteristics and thermal circuit model

Abstract The extensive application of transformers in new energy, electric vehicles, and other fields makes its electromagnetic loss and temperature rise problem pay much attention. This paper analyzes the characteristics of electromagnetic loss and studies the distribution rules of core loss at different voltage excitation and frequency. Based on the thermoelectric analogy theory, the heat circuit model of the transformer is established, and the heat transfer process of heat conduction, heat convection, and heat radiation are considered comprehensively. The accuracy of the simulation results of the electromagnetic loss and the thermal circuit model is verified by experimental measurements. The results show that the error between the simulated and measured values is within 6%, and the maximum error between the simulated and the measured values is 5.94%, which proves the reliability of the model. The results provide a theoretical basis for the temperature rise control of the transformer and help to improve the efficiency and operation safety of the transformer.