The Magnitude Of The Transformer Core Noise

The magnitude of the transformer core noise

The magnitude of the transformer core noise is related to factors such as the rated capacity of the transformer, the performance of the silicon steel sheets, and the magnetic flux density in the core at rated no-load conditions. Additionally, the harmonics of the no-load current, the harmonics of the load current, and the DC bias current in the windings also have a significant impact on the transformer noise.

The main sources of noise include:

(1)Core vibrations caused by the magnetostrictive expansion of the silicon steel sheets;

(2)Core vibrations caused by electromagnetic forces generated at the joints and between laminations of the silicon steel sheets due to magnetic flux;

(3)Vibrations of the windings caused by electromagnetic forces generated by leakage flux as the load current passes through the windings;

(4)Vibrations of the tank (including magnetic shielding, etc.) caused by leakage flux.

Generally, the core vibrations caused by the electromagnetic forces at the joints and between laminations of the silicon steel sheets due to leakage flux are much smaller compared to those caused by the magnetostrictive expansion of the silicon steel sheets and can be neglected. Therefore, the vibrations of the core can be considered entirely dependent on the magnetostrictive expansion of the silicon steel sheets.