Vibration and Noise Measurement of Medium-High Frequency Transformer Cores Under Non-Sinusoidal Excitation

Vibration and acoustic noise are essential in electrical equipment. Amorphous alloy is widely used in the medium- to high-frequency transformer due to its low loss, but its significant vibration and noise cannot be ignored, which will even reduce the reliability of the equipment. Ultra-thin grain-oriented silicon steel (≤0.2 mm) is expected to design medium- to high-frequency transformers due to its high magnetic permeability, high saturation magnetic flux density, and high stability. In this article, the loss characteristic, three-dimensional vibration acceleration, and noise level of three C-type core samples made of ultra-thin grain-oriented silicon steels (GT-050, GT-100) and amorphous alloy CACC30 are measured and analyzed under sinusoidal and rectangular excitations. The mathematic analysis predicts that the vibration acceleration increases with duty cycle decrease under rectangular excitation, which is consistent with the experimental results. The ultra-thin grain-oriented silicon steel has lower vibration and noise under medium- to high-frequency excitation compared with amorphous alloy when the transformer is operated on the non-saturated state. The experimental results and analysis can promote the application of new high-efficiency magnetic materials in medium- to high-frequency electrical equipment.