Sensitivity Analysis of Medium Frequency Transformer Design

Medium-Frequency Transformer Scaling Laws: Derivation, Verif ication, and Critical Analysis

“…It should be noted that all the designs (until the thermal limit) are not limited by the saturation flux, maximum current density, and maximum frequency. Logically, the designs with fine strands are operated at higher frequencies (cf., (32) difference is similar, cf., (32)). However, the designs based on the N97 ferrite material are more efficient compared to the designs using the N27 ferrite.…”

“…The complexity of the mapping between the design space and the performance space can be seen in Fig. 1 (mapping of the operating frequency to the performance space) and has also been observed in [12], [32], [35]. However, to the knowledge of the authors, all the aforementioned aspects have not been brought together up to now.…”

“…The intersection between n opt and f opt represents the global optimum (gradient of the loss function is zero, cf., Fig. 3) and can be expressed as (32) This implies that beyond f opt,0 , the increase of the proximity effect losses in the windings exceeds the reduction of the core losses. The designs with the optimal number of turns feature the following property between the core and winding losses (at any frequency as long as the saturation flux, maximum current density, and maximum frequency are not reached) [5], [22], [24]:…”

“…It can be concluded that the choice of the core material and the winding stranding are interconnected. Designs with large β c −α c differences and reduced d s are operated at higher frequencies (cf., (32)) and feature a reduced B pk J RMS product (cf., (24)). However, high optimal operating frequencies do not directly imply high efficiencies.…”

“…Therefore, such models are typically not used for optimization processes. Explicit analytical equations for the design of optimal MFTs have been successfully given in [9], [22], [24], [32]. Analytical scaling laws (scaling of the characteristics of MFTs with respect to a reference design) have been proposed for different power densities, efficiencies, and frequencies in [22], [23], [33], [34].…”