Transient Characteristics Of Magnetic Suspended Rotor System Based On Uncertain Quantification Of Bearing Characteristics

The multi-electric aero engine is an important development direction for new engines in the future.The magnetic suspension rotor technology is the key to its development,and the key to carrying out related research lies in the determination of the bearing characteristics of the magnetic suspension bearing.At present,most of the research on the bearing characteristics of magnetic suspension bearings is based on the clear control algorithm of PID type transfer function.However,it is difficult to establish the support stiffness and damping model of the magnetic suspension bearings after adopting the new control algorithm.The support characteristics of the system are uncertain,so It is difficult to study the dynamic characteristics of this type of magnetic suspension rotor system.To this end,this paper introduces the method of uncertain quantification into the magnetic levitation rotor system.For the magnetic levitation rotor system with uncertain support characteristics,the dynamic model of the magnetic levitation rotor system is first established using the finite element method,and then the magnetic levitation bearing stiffness and The interval model of damping,and finally based on the Chebyshev orthogonal polynomial interval analysis method,the following research work is carried out on the transient characteristics of the magnetic suspension rotor system with uncertain support characteristics:(1)The influence of the interval median and width of the equivalent rigidity and equivalent damping of the magnetic suspension bearing on the uncertainty of the response of the magnetic suspension single rotor system is analyzed.The results show that the relationship between the relative uncertainty of the response of the magnetic levitation single-rotor system with uncertain support characteristics and the median value of the equivalent stiffness interval shows an increasing change of the power function,while the median value of the equivalent damping interval shows the decreasing function of the power function relationship.By studying the influence of the interval width of the equivalent rigidity and equivalent damping of the magnetic suspension bearing on the response uncertainty of the magnetic suspension single rotor system,it can be seen that when the uncertainty factor is large,the interval width of the equivalent rigidity and equivalent damping is relatively large.When it is large,therotor's operating state may be complicated,and it is difficult to accurately describe the rotor's operating state,and the influence of the support factor uncertainty factor on the relative uncertainty of the system response is nonlinear.(2)The effect of the interval median of the equivalent rigidity and equivalent damping of the magnetic levitation bearing on the response uncertainty of the magnetic levitation double rotor system is analyzed,and the influence of the support characteristics of the intermediate bearing on the response of the magnetic levitation double rotor system with the uncertainty of the support characteristic is analyzed.The results show that the relationship between the relative uncertainty of the response of the magnetic levitation dual-rotor system under uncertain support characteristics and the change of the median value of the equivalent stiffness is more complicated,while the relationship with the median value of the equivalent damping is approximately a decreasing power function.Relationship changes.The supporting characteristics of the intermediary bearing will affect the relative uncertainty of the system response.The relative uncertainty of the system response and the overall trend of the intermediary bearing stiffness change are first as the intermediary bearing stiffness changes drastically,and then tends to be stable.The overall trend of the intermediary bearing damping changes first decreases with the increase of the intermediary bearing damping,and then increases with the increase of the intermediary bearing damping.(3)to study the rotor unbalance uncertainty to support characteristics of the maglev uncertainty dual-rotor system response,the influence of the research results show that the uncertainty and the amount of unbalance to determine the support characteristics of the system,compared to unbalance uncertainty can increase the relative uncertainty of the system response peak and unbalance interval will change the value changes in response to the size of the peak on the lower bound,and will not affect the relative uncertainty of the response of the system.