Research on the Loading Capacity of Solid Insulated Energy Transfer Equipment under Harmonic Actions

Abstract

The external insulation performance of the winding of dry-type transformer is an important determinant of its service life. Caused by harmonic current on dry-type transformer, the additional loss causes additional temperature rise of its internal components. Meanwhile, additional temperature rise will lead to accelerated thermal aging of insulation materials, which further damages the external insulation performance of dry-type transformer windings. Firstly, the harmonic losses of dry-type transformers under different distortion rates are calculated by using the harmonic loss factor. Secondly, calculated by using harmonic loss value, the load capacity of dry-type transformer is under different total harmonic distortion rate. Therefore, based on the above analysis, this paper proposes to reduce the additional temperature rise caused by harmonic loss by reducing the load capacity of dry-type transformer. What’s more, this method can effectively control the temperature rise of the components in the dry-type transformer within the limits. Finally, the relationship between current distortion rate and load capacity of dry-type transformer is obtained by calculation. The results show that harmonic current can increase various loss values of dry-type transformer and reduce load capacity.