Core-form transformer design optimization with branch and bound search and geometric programming

The optimization of power transformers is one of the earliest applications of geometric programming. This approach works well with shell-form transformers, and the constructed models can be solved accurately with the new interior point method based solvers. However, a less well-known fact is that this kind of modeling becomes problematic in the case of core-form transformers. This paper shows a new metaheuristic solution to circumvent the main obstacle which is the calculation of short-circuit impedance.