A Precise Measurement of Windings Axes and Stiffness Coefficient for Power Magnetic Bearing

The axes angle between torque windings and levitation windings in Power Magnetic Bearing is an important parameter for the levitation force model, and it is also the foundation of coordinates conversion utilized in flux oriented control strategy. In addition, as the coefficients in control system model are usually determined basing on a series of hypotheses, there is significant difference between the theoretical calculated values and the practical values. In this paper, a model of magnetic levitation force is established, which includes the axes angle and the rotor eccentric displacement, and a new experimental way based on the model is proposed which can directly and precisely determine the axes coordinates relationship of the two sets of windings and the coefficients. And it would lay the foundation of the precision control for the Power Magnetic Bearing.