Abstract: Unique systems, methods, techniques and apparatuses of power amplifiers are disclosed. One exemplary embodiment is a power system for an active magnetic bearing including at least one power amplifier. Each power amplifier includes a first semiconductor device including a first node coupled to a neutral point node and a second node, a second output node coupled to the neutral point node, a second semiconductor device including a first node coupled to the second node of the first semiconductor device and a second node coupled to a first output node, a third semiconductor device including a first node coupled to a first DC bus node and a second node coupled to the first output node, and a fourth semiconductor device including a first node coupled to a second DC bus node and a second node coupled to the second node of the first semiconductor device.

Abstract: An active magnetic bearing apparatus for supporting a rotor of a rotary machine comprises an axial magnetic bearing unit and a radial magnetic bearing unit mounted directly to one another. One of the axial magnetic bearing unit and the radial magnetic bearing unit is mounted to a support for attachment to a housing of the rotary machine.

Abstract: Unique systems, methods, techniques and apparatuses of active magnetic bearing control systems are disclosed. One exemplary embodiment is a power converter electrically coupled to an active magnetic bearing (AMB) having a plurality of windings, the power converter comprising a DC bus, two capacitors, a first leg, a second leg, and a controller. The capacitors are electrically coupled in series between the positive rail and negative rail, one capacitor being electrically coupled to the other capacitor at a midpoint connection. The first leg comprises a first semiconductor switching device and a first output node. The second leg comprises a second semiconductor switching device and a second output node. The first output node is electrically coupled to the midpoint connection by way of a first AMB winding and the second output node is electrically coupled to the midpoint connection by way of a second AMB winding.

Abstract: Unique systems, methods, techniques and apparatuses of active magnetic bearing control systems are disclosed. One exemplary embodiment is a power converter electrically coupled to an active magnetic bearing (AMB) having a plurality of windings, the power converter comprising a DC bus, two capacitors, a first leg, a second leg, and a controller. The capacitors are electrically coupled in series between the positive rail and negative rail, one capacitor being electrically coupled to the other capacitor at a midpoint connection. The first leg comprises a first semiconductor switching device and a first output node. The second leg comprises a second semiconductor switching device and a second output node. The first output node is electrically coupled to the midpoint connection by way of a first AMB winding and the second output node is electrically coupled to the midpoint connection by way of a second AMB winding.

Abstract: Unique systems, methods, techniques and apparatuses of power amplifiers are disclosed. One exemplary embodiment is a power system for an active magnetic bearing including at least one power amplifier. Each power amplifier includes a first semiconductor device including a first node coupled to a neutral point node and a second node, a second output node coupled to the neutral point node, a second semiconductor device including a first node coupled to the second node of the first semiconductor device and a second node coupled to a first output node, a third semiconductor device including a first node coupled to a first DC bus node and a second node coupled to the first output node, and a fourth semiconductor device including a first node coupled to a second DC bus node and a second node coupled to the second node of the first semiconductor device.

Abstract: A method of making a machine system includes assembling sensing elements with a sensor frame, and contacting ferrite cores of the sensing elements with a locating tool to conform an arrangement of the sensing elements to a cylindrical shape of a surface of the locating tool. The sensing elements are secured to the sensor frame in the determined arrangement, and coupled with a housing of a machine system to monitor position of a rotatable component therein. The ferrite cores may be E-type cores, with bridge connections used to sensitize the sensing mechanism to displacement of a rotatable component in X, Y, and Z directions.

Abstract: An electric motor having a rotor core with a rotatable shaft extending therethrough, and a stator positioned radially outward of the rotor core is disclosed herein. The stator can include at least one pair of first and second coils circumferentially positioned on opposing sides of the rotor. Each pair of the first and second coils includes first and second elements electronically isolated from one another. A first frequency converter is electrically connected to a first conductive wire and a second frequency converter is electrically connected to a second conductive wire. The first conductive wire is wound about the first element of the first coil and the first element of the second coil in series and the second conductive wire is wound about the second element of the first coil and the second element of the second coil in series.

Abstract: Axial magnetic bearings that include a primary winding(s) and one or more compensation windings that provide compensation such that operation of the first and/or second primary windings and the compensation windings results in a net magneto-motive force of around zero ampere turns. Current can selectively flow through one or both of the primary windings of an opposing pair of axial magnetic bearings, while current flows through the compensation windings in manner that compensates for the magneto-motive force generated by the primary winding(s). In at least situations in which the number of turns for at least one pair of compensation windings is generally equal to the number of turns of each primary winding, the net magneto-motive force generated by current flowing through a primary winding of one axial magnetic bearing and through the compensation windings of both axial magnetic bearings can generally be zero.

Abstract: Unique systems, methods, techniques and apparatuses of active magnetic bearing control systems are disclosed. One exemplary embodiment is a power converter electrically coupled to an active magnetic bearing (AMB) having a plurality of windings, the power converter comprising a DC bus, two capacitors, a first leg, a second leg, and a controller. The capacitors are electrically coupled in series between the positive rail and negative rail, one capacitor being electrically coupled to the other capacitor at a midpoint connection. The first leg comprises a first semiconductor switching device and a first output node. The second leg comprises a second semiconductor switching device and a second output node. The first output node is electrically coupled to the midpoint connection by way of a first AMB winding and the second output node is electrically coupled to the midpoint connection by way of a second AMB winding.

Abstract: A method of manufacturing an electrical machine includes selecting a desired threshold control current, selecting dimensions to modify stator teeth of a magnetic bearing based on the desired threshold control current, and modifying the stator teeth using the selected dimensions. A method of producing a rotating machine includes selecting an operating point of a magnetic bearing of the rotating machine, and shaping at least some stator teeth of the magnetic bearing to generate increased force at control currents above the control current at the selected operating point.

Abstract: A method of making a machine system includes assembling sensing elements with a sensor frame, and contacting ferrite cores of the sensing elements with a locating tool to conform an arrangement of the sensing elements to a cylindrical shape of a surface of the locating tool. The sensing elements are secured to the sensor frame in the determined arrangement, and coupled with a housing of a machine system to monitor position of a rotatable component therein. The ferrite cores may be E-type cores, with bridge connections used to sensitize the sensing mechanism to displacement of a rotatable component in X, Y, and Z directions.

Abstract: An electric motor having a rotor core with a rotatable shaft extending therethrough, and a stator positioned radially outward of the rotor core is disclosed herein. The stator can include at least one pair of first and second coils circumferentially positioned on opposing sides of the rotor. Each pair of the first and second coils includes first and second elements electronically isolated from one another. A first frequency converter is electrically connected to a first conductive wire and a second frequency converter is electrically connected to a second conductive wire. The first conductive wire is wound about the first element of the first coil and the first element of the second coil in series and the second conductive wire is wound about the second element of the first coil and the second element of the second coil in series.

Abstract: A method of manufacturing an electrical machine includes selecting a desired threshold control current, selecting dimensions to modify stator teeth of a magnetic bearing based on the desired threshold control current, and modifying the stator teeth using the selected dimensions. A method of producing a rotating machine includes selecting an operating point of a magnetic bearing of the rotating machine, and shaping at least some stator teeth of the magnetic bearing to generate increased force at control currents above the control current at the selected operating point.