Investigation on Intelligent Rotor Vibration Control Based on Electromagnetic Damping Seal

Higher energy level and more compact structure are the trend of centrifugal compressor, which may lead to the rotordynamics instability problems and high vibration. These problems restrict the improvement of the the rotating machinery operation efficiency and bring about potential safety problems, especially, such as the subsynchronous vibration and unbalance vibration. Aiming at the potential instability caused by the excitation of the seal, a seal combined with electromagnetic damping function was designed in “Investigation on the seal structure design and rotor vibration controller for back-to-back centrifugal compressor (GT2016-56900)”. Here, the capability of the Active Magnetic Bearing (AMB)-Hole Pattern Seal (HPS) is investigated in the aspect of function and load characteristic. Furthermore, the electromagnetic damping seal actuator also has the potential to implement the unbalance control. In the aspect of control theory, we combined the damping control algorithm, which is used to control the rotor instability vibration, with the self-optimizing control algorithm for fundamental vibration control of rotor bearing system. The independently optimized control strategy was chosen according to the different frequency vibration waveform. Moreover, we built a comprehensive vibration control experiment platform that is mainly combined with the rotor, tilting pad bearings and electromagnetic damping seal actuator. We did experiment on simulating the instability condition, the control of the instable low frequency vibration, and the control of fundamental frequency vibration. The experimental results show that with the control hardware of high speed FPGA module and the self-optimizing control algorithm, the electromagnetic damping sealing can not only solve the instability caused by the original seal of centrifugal compressor to improve the system stability, but also be used as the active actuator to effectively control the vibration of the rotor system. At the same time, it is also found in the experiment that how to effectively restrain the influence of irrelevant noise and the reasonable selection of initial control parameters have a very important influence on the overall control effect, which is the urgent problem to be solved in the following work. This paper also provides a new design idea and a set of feasible active vibration control strategies for the high speed centrifugal compressor and has guiding significance for solving the problem of multi-frequency vibration and rotor stability of high speed centrifugal compressor.