This paper considers the dynamic characteristics of magnetic bearings used to support a rigid rotor operated at speed up to 18000rpm. The magnetic component of the bearing are of a type reported in the literature, but the earlier analog controllers have been replaced by digital ones. Analog-to-digital and digital-to-analog converters and digital control software were installed in a 486 PC.
The core of control algorithm consisted of assembly and C language to shorten the sampling time. Basic proportional-derivative-integral control was applied to the magnetic bearing system. The dynamic characteristics of the magnetic bearing and rotor system were simulated and tested with digital PID controller.
The precision of rotation was 225㎛ p-p at 4000rpm, 65㎛ p-p at 18000rpm, respectively.
