Design of 3D-Cooling System of 100 kVA/22 kV Distribution Transformer

This paper presents the design of 3D-cooling system of 100 kVA/22 kV distribution transformer that utilizes the liquid insulation of the transformer. It will be ascertained the temperature rise, which is regarded as a difficulty in cooling system design due to the internal insulation values of transformer. The temperature relationship that exists inside the transformer will be determined using the transformer design guidelines in order to design a cooling system under the following conditions: the temperature rise of the upper oil shall not exceed 50°C, the temperature rise of the winding shall not exceed 55°C, and the ambient temperature shall not exceed 50°C. This paper will evaluate the temperature accuracy by comparing the estimated values with the test results using the IEC 60076–2 standard. As the results, the percentage can be obtained using the following formula, where each temperature measurement point has a unique calculated value: The differences in the average HV winding temperature rise of 7%, average winding temperature rise of 5%, and top oil temperature rise of 39% are all significant.