Development of Iterative Algorithm for High Frequency Transformer Used in Solid State Transformers and its Validation via Finite Element Analysis

The optimum design and development of a high-frequency transformer (HFT) is a key requirement in the development of a solid state transformer (SST) for incorporating in smart grid environment. This paper proposes an iteration- based algorithm for the optimum design of a HFT. The algorithm generate optimum design by evaluating an objective function of minimizing the total owning cost (TOC). The unique features of the algorithm developed for the optimum design of HFT include the following: it iterates eight design variables from their minimum values to maximum values and considers four design constraints for selecting the valid designs. This algorithm can work with three different core materials and can select a suitable AC test voltage based on the HFT voltage rating. A case study is conducted on a HFT incorporated in 1000 kVA, 11 kV/415 V, Dyn11 three-phase SST. It enables us to determine the optimum design parameters of HFT. In this case study, the algorithm is iterated with 121,500 design data inputs, generating 19,873 designs that satisfied all design constraints. The optimum design with minimum TOC is selected from the generated 19,873 designs. The optimum design is validated using finite element analysis in ANSYS software. The results obtained in finite element analysis are comparable with the analytical results and hence the algorithm is validated.