The Influence of Load on the Vibration and Noise Characteristics of Transformer

Abstract

In order to further understand and grasp the impact of load on the vibration and noise characteristics of the transformer, this article analyzes the impact of load factors, power factor, harmonic current, three-phase unbalance and other load factors on transformer vibration and noise from the perspective of transformer vibration mechanism. A 10kV/200kVA three-phase oil-immersed distribution transformer was used as the object. Experiments were conducted to study the changes in the spectrum distribution, noise intensity and A-weighted sound pressure level of the transformer vibration and noise under the influence of different load factors. The results show that: when the frequency increases, the amplitude of the 100Hz fundamental frequency in the vibration noise signal increases, and the noise level increases accordingly; when the power factor increases, the amplitude of the odd frequency components in the vibration noise signal gradually decreases with the increase of the power factor. There is no obvious fluctuation in amplitude except 100Hz. When the harmonic current and the three-phase are unbalanced, the spectral components become complicated and accompanied by a large number of odd-order frequency multiplication components. With the increase of harmonic content, the amplitude of vibration noise signal and A-weighted sound pressure level increase significantly; the degree of unbalance and the occurrence of unbalance have a greater impact on the amplitude of vibration noise signal and A-weighted sound pressure level. The research in this paper provides a reference for the noise suppression of power equipment and the fault diagnosis technology based on vibration and noise signals.