Harmonic Current Effect on Vibration Characteristics of Oil-Immersed Transformers and Their Experimental Verification

Harmonic currents can intensify transformer vibrations, seriously threatening their mechanical stability and safe operation. Drawing upon this foundation, the present paper undertakes a thorough simulation and experimental investigation into the vibration characteristics of transformers under diverse harmonic current scenarios. Initially, a multi-field coupling model incorporating both “electromagnetic and structural forces” was developed to simulate and analyze how the vibration acceleration of a transformer is distributed under varying harmonic currents. Subsequently, a specialized transformer harmonic loading and vibration measurement platform was constructed to validate the multi-physical-field vibration simulation. Finally, through a rigorous experimental analysis of transformer vibrations under harmonic currents, this research elucidates the variation patterns of characteristic vibration parameters of transformers under different harmonic currents. The results demonstrate that as the proportion of harmonic current grows, the mean winding vibration acceleration escalates following a power-function law. With increasing harmonic current frequency, the vibration acceleration augmentation in high-voltage (HV) windings exceeds that which is observed in low-voltage (LV) windings. Empirical validation confirms that the discrepancy between the measured and simulated acceleration increases remains within 5%, indicating the effectiveness and reliability of the simulation method. Experimental findings reveal that as the harmonic current content increases, six vibration characteristic parameters—including root mean square value, absolute average value, peak-to-peak value, and mean frequency—exhibit a pronounced upward trend. Furthermore, harmonic currents significantly increase the spectral dispersion and high-frequency components of the vibration signal. These research findings provide valuable references for transformer operation, maintenance, and anti-vibration design strategies.