Research And Design Of Embedded Control System For Active Magnetic Bearings

Active magnetic bearing (AMB) is a kind of novel high-performance bearing, in which rotor can be suspended stably by controllable magnetic force and realize contact-free property between rotor and stator. Due to its advantages of no friction,no lubrication, longevity, low energy consumption, low vibration and noise and so on, it is much better than traditional bearing and has vast and promising applications in following fields: aerospace, energy, transportation, super-high speed and high precision manufacturing, etc. The control system is an important part of AMB system and influences its performance. This paper makes some research and experiment of hardware design and control algorithm for AMB control system.The main works are as follows:First,according to the needs of control system for AMB,and on the base of the analysis of response speed and precision of conrtol system for AMB embedded control system.This research designed a high-performance control platform based on a single DSP:TMS320LF2407A.It integrated multi-channel high-speed synchronous A/D module,high-speed D/A module,versatile communication interfaces and real time data displayer module.This design increases the integration and reliability of system,and reduces the cost.Second,a power amplifier called three-level Hysteresis-MPW(Minimum Pulse Width) with the maximum capacity of 1860VA(310V*6A) is researched and designed to overcome the contradiction of improvement of dynamic performance, reduction of current ripple and reduction of switching power losses of two-level power amplifier. The experimentation results demonstrate that it can overcome the drawbacks of two-level power amplifier and has good steady and dynamic performance.Finally,a control algorithm based on pattern recognition is researched in this paper aiming to the limits of PID and nonlinear characteristic of real AMB, the simulation results of this algorithm prove that it can compensate the nonlinearity of AMB and also improves the stiffness of bearing on the base of rotor's stability.This research has a contribution to integration technology of AMB system.