Optimization of Lead Insulations for HVDC Converter Transformers

This paper explains design considerations for lead and lead-exit insulations of HVDC converter transformer for the purpose of automated design optimization. A HVDC converter transformer should at least deal with AC, DC, and DC polarity reversal stresses, which complicate designing process of insulation structures. Design considerations for those insulations are the types of electrical stresses and design parameters of insulation shapes. The design objective of the optimization is to ensure insulation robustness with reduced size of insulation structures. Optimization results showed 16.72% and 29.07% of length reduction with sufficient robustness, for lead and lead-exit insulations, respectively.