In addition to polyphase rotor currents which are used to create a rotating magnetic field that creates rotor angular force, such as are provided by traditional variable-frequency motor control techniques, the system 20 of the present disclosure may use rotor current variations to create a magnetic field component that imparts a net radial force on the rotor 24 to control a radial position of the rotor 24, and which may, for example, be configured to center the rotor 24 inside of the stator 25 with a net radial force (non-cancelling forces on opposite sides of the rotor). This control may be used to compensate for small mass imbalances in the rotor 24 that can tend to cause the rotor 24 to rotate about its center of mass instead of its geometric center. This control may also be used to compensate for small magnetic field strength imbalances that can tend to pull the rotor 24 unevenly in radial directions relative to the stator 25.