Iron Loss and Acoustic Noise of Model Transformer Coreunder DC Biased Magnetization

摘要

The iron losses and acoustic noises of a model transformer core made of grain-oriented electrical steel sheets were investigated under DC biased magnetization while altering the amplitude of magnetic flux density, B., and the DC biased magnetic field, H_(DC), applied by the third windings. The iron loss increased as Hoc increased up to 100 A/m, while over 100 A/m, the increment of iron loss by DC biased field rapidly decreased. The increase in iron loss at the same H_(DC) was largest at B_m:1.1 - 1.5 T. Meanwhile, the acoustic noise increased monotonically as H_(DC) increased. The acoustic noise of odd-order harmonics was drastically increased under DC biased magnetization, and this is the primary cause of the increase in acoustic noise.