EXPERIMENTAL STUDY OF THE THERMAL PERFORMANCE BEHAVIOR OF ELECTRIC POWER TRANSFORMERS

Abstract

Electric power transformers of various capacities are one of the most important units of the electrical system. They are considered to be economically costly and have negatively impacted the event of their breakdown. Most electrical transformers fail to perform when the temperature rises and it is mostly requested at its peak. Therefore, it needs periodic maintenance to prevent it from collapsing. Experimentally, distribution transformers (250 kVA, 11/0.416 kV, Core type, Oil engrossed, and Natural convection) have been collected and provided with several sensors to carry out required tests under different operating conditions. All tests were done at AL-Wazyria Company, Iraq for electrical industries. Analyzing the thermal performance of the electrical transformer is related to choosing the appropriate and effective method for cooling the transformer. From the results, it was observed that the oil temperature of the electrical transformer is affected by the temperature of the ambient and the windings, to varying degrees. Accordingly, changing the temperature of the air surrounding the fin has a significant effect on the oil temperature compared to the temperature change of the coils. Therefore, any method that targets the external shape of the transformer and the fins may give the best thermal performance with respect to the improvements that target the coils.