By elevating the operational frequency, there exists the potential to diminish the transformer’s size and weight while simultaneously augmenting its power density and efficiency. Nonetheless, this approach is not without its challenges and practical limitations. This research delves into the optimal design considerations for core-type medium frequency transformers. In comparison to their shell-type counterparts, core-type transformers offer significant advantages, including ease of repair and maintenance, more efficient cooling, and superior suitability for high-voltage applications in transmission and distribution transformers. Additionally, we conducted a comparative analysis between copper wire split winding and Litz-wire winding for core-type transformer applications. The utilization of geometric programming facilitates the derivation of an efficient and dependable global optimal solution for the design of solid-state core-type transformers.