A magnetically-levitated blood pump with an optimization method that enables miniaturization and supercritical operation. The blood pump includes an optimized annular blood gap that increases blood flow and also provides a reduction in bearing stiffness among the permanent magnet bearings. Sensors are configured and placed optimally to provide space savings for the motor and magnet sections of the blood pump. Rotor mass is increased by providing permanent magnet placement deep within the rotor enabled by a draw rod configuration.

A magnetic bearing vacuum pump comprises: a first displacement signal generation section configured to amplify, by a resolution multiplying factor K of K>1, a displacement modulated wave signal modulated according to a displacement of the rotor from a predetermined position to generate a high-resolution displacement signal in a first displacement region including the predetermined position; a second displacement signal generation section configured to generate a low-resolution displacement signal in a larger second displacement region including the first displacement region; a selection section configured to select either one of the high-resolution displacement signal or the low-resolution displacement signal based on an unsteady-state response signal obtained by excluding a steady-state whirling displacement component from the high-resolution displacement signal or the low-resolution displacement signal; and a bearing control section configured to control the magnetic bearing based on the displacement signal selected by the selection section.

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.

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.

When a duration of current noise caused by a PWM control of each excitation amplifier is Td, a cycle of a PWM carrier signal is Tpwm, an on-duty upper limit of the PWM carrier signal under quiet environment without disturbance is Tonu, and an on-duty lower limit of the PWM carrier signal under the quiet environment without the disturbance is Tonl, the AD sampling period includes a first AD sampling period between a point after a lapse of the time Td after a start of the cycle Tpwm and a point after a lapse of a time (TpwmTonu) from the start of the cycle Tpwm, and a second AD sampling period between a point after a lapse of a time (TpwmTonl+Td) from the start of the cycle Tpwm and an end point of the cycle Tpwm.

A tunable and resettable shock sensor using a parallel dipole line (PDL) trap system is provided. In one aspect, a shock sensor includes: a PDL trap having a pair of diametric magnets separated from one another by a gap g.sub.M, and a diamagnetic rod levitating in between the diametric magnets; and contact pads below the PDL trap, wherein the contact pads are separated from one another by a space that is less than a length l of the diamagnetic rod. A shock monitoring system is also provided that includes a network of the shock sensors, as is a method for shock monitoring using the shock sensors.

A tunable and resettable shock sensor using a parallel dipole line (PDL) trap system is provided. In one aspect, a shock sensor includes: a PDL trap having a pair of diametric magnets separated from one another by a gap g.sub.M, and a diamagnetic rod levitating in between the diametric magnets; and contact pads below the PDL trap, wherein the contact pads are separated from one another by a space that is less than a length l of the diamagnetic rod. A shock monitoring system is also provided that includes a network of the shock sensors, as is a method for shock monitoring using the shock sensors.

When a duration of current noise caused by a PWM control of each excitation amplifier is Td, a cycle of a PWM carrier signal is Tpwm, an on-duty upper limit of the PWM carrier signal under quiet environment without disturbance is Tonu, and an on-duty lower limit of the PWM carrier signal under the quiet environment without the disturbance is Tonl, the AD sampling period includes a first AD sampling period between a point after a lapse of the time Td after a start of the cycle Tpwm and a point after a lapse of a time (TpwmTonu) from the start of the cycle Tpwm, and a second AD sampling period between a point after a lapse of a time (TpwmTonl+Td) from the start of the cycle Tpwm and an end point of the cycle Tpwm.

A magnetic bearing supports an object to be supported in a noncontact manner by means of a composite electromagnetic force of first and second electromagnets. A processor-based controller causes a first current and a second current to be controlled according to the following equations,

[00001]$\begin{array}{cc}{i}_1=\frac{g_0-\mathrm{ax}}{g_0}.Math.\left(i_b+i_d\right)& \left(1\right)\\ i_2=\frac{g_0+\mathrm{ax}}{g_0}.Math.\left(i_b-i_d\right)& \left(2\right)\end{array}$

where i.sub.1 is the first current flowing to the first electromagnet, i.sub.2 is the second current flowing to the second electromagnet, i.sub.d is a control current, i.sub.b is a bias current, g.sub.0 is a reference gap length, x is a displacement amount of the object to be supported with respect to a center position, and a is a predetermined correction coefficient.

The invention relates to a rotary machine comprising a stator and a rotatably mounted rotor, with one or more magnetic field sensors arranged stationary relative to the stator at a radial distance from a stationary axis, at least one measuring device which configured to detect magnetic field changes with the aid of the aforementioned magnetic field sensors, a rotor which is configured to generate one or more electrical signals in each case, said signals having signal components which correspond to the rotor rotation frequency and to the distance between magnetic field sensor and rotor in each case, wherein a demodulator unit carries out a demodulation of signals generated by or derived from the magnetic field sensors, such that a signal is generated which corresponds to the distance between the rotor and the magnetic field sensor.