Optimization Simulation Analysis of Leakage Magnetic Field and Loss Characteristics of High Frequency Nanocrystalline Transformer

Increasing the switching frequency of the converter can reduce the size of the transformer. However, as the switching frequency increases, the losses and temperature of transformer also increase, especially the core loss. Improving the calculation accuracy of core loss models is important for the design and research of high frequency transformers. Nanocrystalline materials have a unique nanoscale grain size and a special microstructure that gives them a high saturation magnetic induction strength and permeability, resulting in smaller size and weight at high frequencies, and have gained widespread popularity in recent years. However, compared to other soft magnetic materials, nanocrystalline strips have high permeability and leakage inductance causes increased eddy current losses on the thin walls on both sides, resulting in high localized temperatures. The finite element model of nanocrystalline high frequency transformer is established by the Ansys/Maxwell software in this paper and the effect of temperature is considered on the core with the leakage magnetic, using Icepak to perform a bidirectional coupling calculation of electromagnetic and temperature. With two different primary and secondary winding arrangements, this model calculated the core losses and temperature distribution. It verified that as the leakage inductance increases, the core loss grows and the temperature rise accelerates.