Magnetic bearings with DC Bias: Design and optimum material choice

The excitation of magnetic bearings can consist of the "basic excitationldquo and of the "control excitationldquo. According to this the magnetic flux is not symmetrical to the zero-point of the magnetization diagram. Therefore calculation of the iron-losses must take into account changed loop of the used B-H curve. And on the other hand the area of the loop depends on the basic-excitation current. Thus the destination of the loss has to take into account the different values of the basic-current. The iron losses are less if a DC bias-current is used.