Research on the Dynamic Simulation Process of Hot Spot Temperature Rise of Oil-immersed Transformer

As one of the widely used equipment in the power network, the safe operation of oil-immersed transformers is a basic element of the safety work of the power network. Due to the transformer daily load fluctuation changes drastically, in normal operation, with the change of load rate transformer temperature fluctuates within a certain range. In order to grasp the transformer hot spot dynamic temperature rise change process law, this paper on the model for the SB-M-630/10 model oil-immersed transformer to build “electromagnetic-fluid-thermal” multi-field coupling model, in the imposition of step-type function excitation on the basis of the use of the finite element method to get the transformer fine two-dimensional dynamic temperature distribution of the windings as well as the hot spot. temperature 97.461°C. According to the simulation data, the hot spot temperature rise law is fitted and analysed, and it is concluded that the hot spot temperature rise with time is saturated exponential function law growth, and based on the centralized parameter method to get the physical law of the parameters of the fitted curve. The maximum error between the simulation value and the test value of the hot spot temperature rise of the transformer winding is only 2.586 K, which verifies the accuracy of the distribution law of the hot spot dynamic temperature rise of the winding obtained in this paper, and provides a powerful support for the detection of the quality defects of the transformer and the evaluation of its performance.