| Abstract |
Medium voltage, medium frequency transformers (MFTs) are much smaller in size and weight comparedto conventional low frequency transformers. The MFTs are very attractive for applications where fullcontrol of the power flow and high power density are required, such as power electronic interface insmart grids and traction converter system. With reduced size, the optimal design of MFTs becomesmore challenging due to the high isolation requirement and thermal stress. This paper presents a designand optimization methodology for MFTs with emphasis on thermal and insulation design. The improvedthermal model for multi-layer windings consisting of litz-wire and the analytical calculation of maximumelectric field in core window area are included in the optimization process. By using the methodology,the optimal designs of a 25 kW/4 kHz MFT with two commonly used core materials are compared. Thepossibility of volume reduction by increasing the operating frequency is also investigated. |
