Research Of Control System For Active Magnetic Bearing

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 CPU of digital controller for Active Magnetic Bearing(AMB) . Based on the F2812 DSP, hardware for Active Magnetic Bearing controller is designed and the internal analog multiple-way switch is adopted to sample the four displacements of Active Magnetic Bearing. The system consists of four 12bit A/D and four 10bit D/A. I/O port of DSP is applied to simulate the time sequence which serial DA (TLC5615) requires likes parallel connection and the use of this method is discussed.Incomplete differential calculus PID control strategy is used while the embedded C language and DSP assembly language are adopted to develop the digital control software. The coupling characteristic of magnetic suspension rotor which is in five degree of freedom are analyzed, drawing the conclusion that the system can apply decentralizing control under the condition of 20000r/min. Based on the mathematics model ,the PID parameters are simulated by the method of trial-and-error , experiments in the lab are carried out and further more analog circuit is used to testify the simulated result. The displacement signal of degree of freedom is measured with four eddy flow sensors in differential way. Linearity and switch hybrid power amplifier is used to reduce power consumption and ripple current, at the meantime improves the controlling characteristics. The controller designed successfully enables the test rotor system realize the static suspension experiment for AMB rotor, by which the displacement viabration peak-to-peak amplitude of rotor in each freedom degree is less than 3μm.It is proved by experiment that the controller designed has the characteristics of good stability, high reliance ,easy to use and high control precision, whose precision reaches what is expected.