Temperature Simulation of 800 kVA Converter Transformer Windings Considering the Effects of High-Order Harmonics

In order to address the temperature simulation issue of the converter transformer under the influence of high-order harmonics, this paper establishes an SOO kVA electromagnetic-thermal multi-physical field simulation model. The impact of load level and ambient temperature on the internal hot spot temperature is investigated. The results indicate that the presence of harmonic currents has a significant impact on the assessment of winding losses and temperature rise in the converter transformer. Compared to the temperature results based solely on fundamental frequency currents, the average loss density of the grid-side and valve-side windings increased by 1.1249 times and 1.0867 times, respectively. The hot spot temperature of the grid-side winding increased by $2.7^{\circ}\mathrm{C}$, and the hot spot temperature of the valve-side winding increased by $1.6^{\circ}\mathrm{C}$.