Influence of Load Factors on Distribution Transformer Noise

Theoretical relations between load factors and distribution transformer noise are analysed. A 10kV/400kVA three-phase oil-immersed distribution transformer is used for sound pressure level test in various load conditions including various load ratios, unbalanced loads and power factors. The sound pressure levels of distribution transformer in different load conditions are compared and analysed. The results can be referenced for the field noise and vibration control of distribution power transformers.