Study Of Control System On Magnetically Levitated High-speed Motors

Due to the advantages of small volume,high power density and high efficiency,high speed machines are emerging as a key technology for applications such as turbocharger,flywheel energy storage system,compressors.Compared with conventional low-speed machine,the rotor speed is very high,so that mechanical bearings are difficult to meet the requirements of high-speed operation.Active magnetic bearings(AMBs),which support a rotor by magnetic forces,having advantages of non-contact,without lubricant to conventional mechanical bearings,are attracting more and more interests in the high speed machines.Firstly,the analysis of the basic principle of active magnetic bearings,the model of single freedom AMB system and the model of magnetically levitated high-speed motor system with four radial degrees of freedom are introduced.Then based on traditional PID control and internal model control(IMC),IMC-PID control has been proposed,the adjustment of traditional PID control with three parameters is reduced to one,which greatly simplifies the debugging process.Meanwhile the model of magnetic levitation motor system considering unbalance vibration is introduced and the unbalance vibration characteristics has been analysed and simulated.Then two unbalance vibration control algorithms,i.e.,(adaptive variable step-size LMS feedback algorithm and variable polarity control based on adaptive notch filter)have been introduced,and the performance of magnetically levitated high-speed motor system with the two unbalance vibration control algorithms have been analysed in simulantion under various conditions,such as frequency match,frequency mismatch and noise problem.In this paper,the magnetically levitated high-speed motor system experiment platform hardware and software systems based on dSPACE are introduced.Rotor static levitation experiment and anti-jamming.experiment were carried out to validate the effectiveness of IMC-PID algorithm.The two unbalance vibration control algorithms have been added to the magnetically levitated high-speed motor system for debugging respectively.The validity of the two unbalance vibration control algorithms was proved by online simulation and experiments.