Analysis on Sound and Vibration Characteristics of Power Transformer under different Harmonics in Load Condition

With the increasing intensity of power demand and the strong correlation between power demand and economic development, distribution transformers need to be installed close to residential and office areas. The increase of power demand and nonlinear loads greatly enlarged the vibration and noise emitted by distribution transformer. Therefore, it is necessary to study the vibration and noise characteristics of distribution transformer under the influence of harmonics, so as to provide a research basis for the vibration and noise suppression of distribution transformers. In this paper, a typical distribution transformer has been tested under different harmonic exaction in load experiment condition. The vibration response verses excitation frequency and the vibration amplitude distribution character under different excitations are studied. Under harmonic excitation, the vibration response of transformer is mainly under difference and sum frequency of the excitation. Compared to the impact test result, it is found that the vibration response amplitude changes with excitation frequency is closely related to impact response of the transformer oil tank. The sound level distribution is identical to the surface vibration distribution of the oil tank.