Vibration Simulation and Experimental Analysis of Medium-Frequency Transformer With the Nanocrystalline Core

Abstract

Medium-frequency transformer (MFT) is the core component of high voltage and large capacity DC/DC converter, but high frequency and high power density will lead to intensified transformer vibration. Magnetostriction and air gap Maxwell force are the main sources of vibration and noise. In this paper, nanocrystalline alloy with high saturation magnetic density, high magnetic permeability and low high frequency loss is used as the core of MFT to study its vibration characteristics. Considering the influence of transverse isotropy of nanocrystalline alloy core mechanical properties, the transient electromagnetic field-structure field weak coupling calculation method based on ANSYS finite element method is used to calculate two MFTs with 10kVA/5kHz shell-type and core-type nanocrystalline cores under no-load sine condition. The calculated volume force is imported into the structural field to obtain the vibration acceleration and displacement changes of the core, and the simulation value is compared with the experimental measurement value. The results show that the vibration of the shell-type core is stronger than that of the core-type core under the action of Maxwell force and magnetostrictive force. And the vibration acceleration frequency is twice the excitation frequency. The research in this paper can provide a basis for the design and optimization of vibration and noise of MFT.