How is the iron loss related with the choice of specific magnetic loading?

The iron loss in electrical machines, such as transformers, motors, and generators, is directly related to the choice of specific magnetic loading. Magnetic loading refers to the magnetic flux density (usually measured in Tesla) in the core material. Iron loss, also known as core loss, is composed of hysteresis loss and eddy current loss, both of which depend on the magnetic loading.

1. Hysteresis Loss: This type of loss is related to the magnetization and demagnetization of the core material as the magnetic field changes. The hysteresis loss is proportional to the area of the hysteresis loop for the material, which in turn depends on the maximum magnetic flux density. Higher magnetic loading leads to a larger hysteresis loop and thus increases the hysteresis loss. It can be approximately expressed by the formula: [P_h = eta B_{max}^n f V] where (eta) is the hysteresis coefficient, (B_{max}) is the maximum flux density, (n) is the Steinmetz exponent (typically between 1.5 and 2.5 for most materials), (f) is the frequency of magnetic reversal, and (V) is the volume of the core.

2. Eddy Current Loss: This loss is caused by circulating currents induced in the core material by the changing magnetic field, which in turn heats the core. Eddy current loss