Abstract: In order to solve the difficult that achieves the high stiffness and high rotational speed of grinding machine system supported by electromagnetic bearing (EMB) at the same time because of the EMB’s nonlinearity, electromagnetic force as the input and electromagnetic force formula, electromagnet and power amplifier are integrated to electromagnetic force components. On the basis of thinking of relationship and effects above, the excited current is calculated inversely in order to ensure controller output signal. The advantages of this method are that the calculation of electromagnetic force and the controller de-sign can be considered separately without considering the nonlinearity. The experimental results show that the two indexes can be achieved at the same time and the effects come from electromagnetic force perturbation can be overcame by means of being adopted H￥ controller with electromagnetic force components.

Key words: Eddy current, Electromagnetic bearing (EMB), Excited current, Leak magnetic, Nonlinearity