Gyroscopic effect suppression of magnetic levitation molecular turbo without speed sensor
The destabilizing gyroscopic effects in magnetically levitated molecular turbopumps are often in-adequately mitigated when the speed sensor is faulty or absent.To address this challenge,this study pres-ents a novel gyroscopic effect suppression method that operates without the need for a speed sensor.Initial-ly,a complex coefficient model of the molecular turbopump's rotational dynamics was developed based on rotor dynamics principles.Subsequently,the rotational speed is estimated and integrated into the control system using a variable phase shift angle,double-input adaptive notch filter with nonlinear frequency esti-mation.To further suppress the gyroscopic effects,filter cross-feedback was incorporated into a PID con-trol framework.The stability of the proposed system was analyzed using a double-frequency Bode plot,and the cross-feedback parameters were designed in conjunction with insights from the Nyquist plot.Final-ly,ramp-up experiments were conducted on a magnetically levitated molecular turbopump platform.The experimental results demonstrate that the estimated speed in the medium-to-high-speed range exhibited a maximum deviation of only 2.04 Hz from the actual speed.At a molecular pump speed of 350 Hz,the im-plementation of cross-feedback reduced the amplitude of the angular displacement response at the whirl fre-quency from-37.34 dBV to-60.11 dBV.Similarly,the amplitude at the nutation frequency decreased from-57.24 dBV to-76.15 dBV,rendering the signal comparable to ambient noise levels.These ex-perimental results validate the efficacy of the proposed gyroscopic effect suppression method.
万方数据
维普
