Hysteresis losses

Hysteresis losses, the losses caused by the effect of hysteresis, particularly in transformers, which are expressed in a phase shift between magnetic flux Φ and current I. Hysteresis losses and eddy current losses are also referred to together as iron losses. When materials are remagnetized, energy must be expended to change the orientation of the internal elementary structures (white areas). This turning causes heat in the iron. The magnetization characteristic curve (B-H diagram) of the iron shows that the positive and negative magnetization of the material do not follow the same path; there is a hysteresis. Each remagnetization results in specific heat losses per volume, which correspond to the circulation integral on the magnetization characteristic curve. Experts use the terms hysteresis losses or remagnetization losses to describe this effect. The resulting hysteresis losses increase quadratically with the magnetic flux density and linearly with its frequency. Hysteresis losses can be reduced by selecting the appropriate material.