Noise characteristics of the new converter transformer under DC bias

摘要

Harmonic magnetic fluxes in transformer's core and harmonic currents in grid-side winding can be restrained via the inductive filtering technology, and running noise of the transformer is reduced at the source. The A-weighted sound levels of the measuring points are measured under DC bias. The noise test results verify this theory. When the fully-tuned filters matched with the new converter transformer are inputted and not inputted, the noise response curves of the measured points are compared. The fitting coefficients of the noise values at 1250 and 1600 Hz with the unbalance degrees of the trigger angle are obtained.