Design And Research Of High Power Medium Frequency Transformer

Increasing operating frequency will not only increase the efficiency of magnetic-integrated power transmission system, but also decrease its volume and reduce cost. The high power medium frequency transformer(MFT) is the key component of medium frequency magnetic-integrated power transmission system, and it is required to be with high efficiency, high power density and stability. Design and research of MFT are meaningful to the development of power transmission system.As the geometry of core is customized, the freedom and the complexity of the MFT design are highly increased. At the same time MFT should meet the request of the high power, the high voltage and the high frequency. It is necessary to optimize the design of the MFT.The multi-physics characteristics of MFT are directly relative to its working performance. The changes of working environment have many effects on the MFT multi-physics field. The MFT works with the power electronics system, then the leakage inductance of MFT will affect the control of the power electronics system, which increases the importance of leakage inductance analysis. The power electronics system inversely affect on the MFT loss model and temperature field. The change of working frequency and the non-sinusoidal excitation lead to the change of loss model. The decrease of heat transfer area and the increase of heat generation density lead to the change of temperature field. It is significant to build up multi-physics field model of MFT.The calculation of the leakage inductance, losses and temperature field of the MFT, based on the multi-physic FEM model, are performed. The results are verified by experimental results of small power prototype.