Abstract: A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages in response to the determined phase currents and a variable commutation angle. The angle is selected to correspond to an axial attractive force of the stator that maintains a levitation of the impeller at a centered position within the pumping chamber.

Abstract: A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages during a running state in response to a desired impeller speed and an actual impeller phase. The controller has a startup interval during which the commanded values of the phase voltages are determined in response to a pseudo impeller phase and in response to a ramping gain factor.

Abstract: A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages in response to the determined phase currents and a variable commutation angle. The angle is selected to correspond to an axial attractive force of the stator that maintains a levitation of the impeller at a centered position within the pumping chamber.

Abstract: A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages in response to the determined phase currents and a variable commutation angle. The angle is selected to correspond to an axial attractive force of the stator that maintains a levitation of the impeller at a centered position within the pumping chamber.

Abstract: The magnetic balance is verified of a magnetically-levitated impeller of a centrifugal pump with a pump housing having levitation magnets. The impeller includes embedded magnets and is movable within a chamber in the pump housing between first and second sides of the chamber. The centrifugal pump is mounted on an acceleration fixture while the impeller is held against a predetermined one of the first and second sides by the levitation magnets. A plurality of predetermined accelerations are applied to the acceleration fixture to exert a plurality of different forces of acceleration on the impeller. A determination is made whether the impeller detaches from the predetermined side as a result of each different force of acceleration to identify adjacent forces for which a transition occurs between detaching and not detaching. The transition is compared with a desired retention force to determine whether the pump achieves magnetic balance.

Abstract: The magnetic balance is verified of a magnetically-levitated impeller of a centrifugal pump with a pump housing having levitation magnets. The impeller includes embedded magnets and is movable within a chamber in the pump housing between first and second sides of the chamber. The centrifugal pump is mounted on an acceleration fixture while the impeller is held against a predetermined one of the first and second sides by the levitation magnets. A plurality of predetermined accelerations are applied to the acceleration fixture to exert a plurality of different forces of acceleration on the impeller. A determination is made whether the impeller detaches from the predetermined side as a result of each different force of acceleration to identify adjacent forces for which a transition occurs between detaching and not detaching. The transition is compared with a desired retention force to determine whether the pump achieves magnetic balance.

Abstract: A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages during a running state in response to a desired impeller speed and an actual impeller phase. The controller has a startup interval during which the commanded values of the phase voltages are determined in response to a pseudo impeller phase and in response to a ramping gain factor.

Abstract: A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages in response to the determined phase currents and a variable commutation angle. The angle is selected to correspond to an axial attractive force of the stator that maintains a levitation of the impeller at a centered position within the pumping chamber.