Learning Forum

[VivekKamble]

What is saturation and why and how does an electrical machine saturate?

[CB]

When we say saturation in electrical machines we are speaking about magnetic saturation. If we increase the mmf of the magnet or if we increase the current in the coil, the flux density inside the iron of the machine is also increased. There is a limit beyond which magnetic flux density in the core will not increase proportional to the mmf. This limit is called magnetic saturation.

[rtk]

Hello,

How does it affect the electrical machine?

[CB]

Hi @cblair,

When magnetic saturation sets in, the machine performance will not increase much even the magnetomotive force (MMF) is increased. You can understand these limits of the steel used in the machine by looking at the BH-curve of the steel. The knee point where the curve starts becoming parallel to X axis (H) is where the steel starts saturating

A saturated core requires more magnetizing current. This will increase I2R loss in the winding thus overheating the machine.

[isaichaitanya]

how to test magnetic saturation effect in pmsm using ansysnn

[kunaldugvekar]

You can check magnetic flux densities & compare it with used materials saturation levels. Also for a machine, a simple OCC test & voltages non-linearity can indicate saturation in the machine.