Accuracy improvement of thermal distribution analysis of 10 kV dry-type iron-core reactor

Hotspot temperature is a key factor affecting the safe operation for power equipment like reactor. The different distribution of the magnetic field in the iron-core and windings results in nonuniform distribution of the electromagnetic losses. However, the influence of non-uniform losses on the temperature distribution is rarely discussed in the previous studies. In this paper, the thermal behavior of 10 kV dry-type iron-core reactor considering the influence of non-uniform losses is studied to obtain more accurate simulation results. First, the winding model with separate coils is used instead of traditional cylinder structure, and the loss of each coil is obtained by equivalent calculation method. Then, the thermal characteristics of reactor with different winding models and loss distributions are analyzed. In addition, the effect of the above factors on windings temperature distribution is discussed. Finally, the simulation results are compared with the test results of 10 kV dry-type reactor in 110 kV indoor substation. The result indicates the simulation result considering the non-uniform losses distribution is closer to the measured result. The temperature distribution of windings in vertical direction is more consistent with the real situation as well.