Control of magnetic bearing - supported rotors

Abstract

Rotor systems are provided comprising rotor, magnetic bearings and a magnetic bearing controller. The controller is one which varies in accordance with linear parameters and is preferably responsive to linear matrix inequalities. High speed, low loss flywheel systems, especially electromagnetic flywheel batteries are facilitated through such rotor systems.

What is claimed is:  
     
         1 . A rotor system comprising rotor, magnetic bearings, and a linear parameter varying controller for the magnetic bearings.  
     
     
         2 . The rotor system of  claim 1  wherein said controller is responsive to linear matrix inequalities.  
     
     
         3 . The rotor system of  claim 1  wherein rotor vibration or coil current is minimized with respect to those experienced with conventional control.  
     
     
         4 . The rotor system of  claim 1  wherein the control algorithym is obtained for the magnetic bearings at minimum nominal operating speed and at maximum nominal operating speed and linear interpolation is employed between the minimum and maximum operating speed controllers through linear parameter varying control.  
     
     
         5 . The rotor system of  claim 1  wherein the controller is substantially stable over the range of operating speeds from nominal minimum to nominal maximum operating speed.  
     
     
         6 . The rotor system of  claim 1  wherein said controller accounts for gyroscopic effects experienced by the rotor.  
     
     
         7 . The rotor system of  claim 1  wherein said controller minimizes hysteresis and eddy current losses during operation of the system.  
     
     
         8 . The rotor system of  claim 1  wherein bias current is less than one-half saturation level in the magnetic bearings.  
     
     
         9 . The rotor system of  claim 7  wherein said minimization is attained through application of bias current into the control algorithm.  
     
     
         10 . A controller for a magnetic bearing system for a rotor system, said controller being a linear parameter varying controller.  
     
     
         11 . The controller of  claim 10  responsive to linear matrix inequalities.  
     
     
         12 . The controller of  claim 10  wherein rotor vibration or coil current is minimized with respect-to those experienced with conventional control.  
     
     
         13 . The controller of  claim 10  wherein the control algorithm is obtained for the magnetic bearings at minimum nominal operating speed and at maximum nominal operating speed and linear interpolation is employed between the minimum and maximum operating speed controllers through linear parameter varying control.  
     
     
         14 . The controller of  claim 10  which is substantially stable over the range of operating speeds from nominal minimum to nominal maximum operating speed of the rotor.  
     
     
         15 . The controller of  claim 10  which accounts for gyroscopic effects experienced by the rotor.  
     
     
         16 . The controller of  claim 10  which minimizes hysteresis and eddy current losses during operation of the rotor.  
     
     
         17 . The controller of  claim 10  wherein bias current is less than one-half saturation level in the magnetic bearings.  
     
     
         18 . The controller of  claim 17  wherein said minimization is attained through application of bias current into the control algorithm.