Air Gap Layout optimization Method for Inductor-integrated High-power High-frequency Transformer

Inductor-integrated high-power high-frequency transformer can achieve soft switching of power semiconductor devices and reduce switching loss. That is widely used at high-voltage and high-power applications such as renewable energy grid-connected systems. The method of dividing a single air gap into several air gaps can effectively reduce the additional loss caused by the air gap. However, cutting the air gap in amorphous or nanocrystalline strips commonly used at large-capacity high-frequency applications will break the interlayer insulation and increase the eddy current loss at the core incision. Hence, the number of air gaps should be as few as possible. This paper introduces that three quasi-distributed air gaps can be arranged at three regions of the magnetic core according to the certain rule to effectively decrease winding loss. Finite element analyses (FEA) will be utilized to validate that the proposed method is better than that of the six quasi-distributed air gaps.