Determination of the thermal class of 800KVA compact electric power substation made by Irantransfo Substations Development Company

In this research, the compact power substation with 800KVA capacity that is produced by Irantransfo Substations Development Company, has been modeled and its thermal class is determined. Modeling of this compact power substation that include a three-phase cast resin dry transformer placed in the enclosure chamber carried out in three-dimension. Then the desired parameters such as fluid flow, pressure drop and temperature distribution in significant parts are investigated. In order to verify the accuracy of the results, four sensors were placed in suitable locates to compare the results of the analysis with the measured values of these sensors. The results of the modeling in comparison with the experimental results show a difference of up to 5.8K. By applying data according to IEC62271-202 standard and appropriate boundary conditions, the maximum temperature difference which occurs in low voltage bobbin is 12K. So the thermal class will be 15K according standard definition. Although it was 14% lower than the laboratory results, the thermal class of this substation also determined in the Laboratory of Electrical Industries of Iran 15K and indicate the good results of this study.