Vibration Characteristics of High-Frequency Transformer Under Square-Wave Excitation in Different Operating Conditions

High Frequency Transformer (HFT) exhibits advantages including reduced size, lightweight construction, and high power density, but generates significant high-frequency vibration under square-wave excitation. This paper first analyzes the primary excitation sources, specifically investigating the mechanisms underlying core vibration caused by magnetostriction, Maxwell forces acting on the core structure, and Lorentz forces exerted on the windings. Following this, a dedicated vibration test platform is established for symmetric square-wave excitation. Finally, vibration test is conducted under both no-load and loaded operating conditions to measure the vibration characteristics of the transformer core and windings. Results demonstrate that under square-wave excitation, the dominant vibration frequency for both the core and the windings occurs at twice the excitation frequency. Additionally, the core vibration amplitude exceeds that of the windings, and the overall vibration magnitude and distribution exhibit frequency-dependent variations.