Design And Research On The Active Magnetic Bearing Controller System

Being the newest, the most advanced DSP of TI(Texas Instruments) company's C2000 products at present, TMS320F2812 is used in this thesis as the main CPU of our digital controller of Active Magnetic Bearing(AMB). The hardware is designed ,which has 6 A/D channels of 12bits,5 D/A channels of 12bits and 3 ways of serial communication for data transmission: RS-232,RS-485,RS-422. The centralized sampling and separate sampling of multiple channels is realized. And CPLD is used for the centralized output and separate output of the 5 D/A channels.A digital control software was developed with the C and DSP assembly language in which PID control algorithm is adopted. The PID parameter is modified in the experiments and the experimental results show that the five-degree freedom magnetic rotor can suspend and rotate at high speed stably in which the maximum vibration amplitude of the static suspended rotor is below 5μm ,as for the high speed rotating of 21000r/min, the maximum vibration amplitude of 4 radial direction is below 20μm while that of axial direction is below 9μm.Also, for improving the disadvantages of the original algorithm, the self-searching PID control algorithm is developed based on the PC.Also, the discrete periodic T of the PID digital control algorithm is discussed,and the conclusion that the discrete periodic T is only equal to an internal parameter,but has no real physical meaning within the Active Magnetic Bearing digital controller system is obtained.The fine performance of the AMB system shows the good stability,high reliability and simple way of use of the digital controller , and the control precision has reached the anticipation.