Position detection device of AMB
AssigneeSkf Magnetic Mechatronics
InventorsBertrand Haffray, Olivier Lemarchand
Life of this patent
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Abstract
A position detection device of active magnetic bearings (AMB's) maintaining the position of a rotating shaft and comprising two sensing inductance coils, the position detection device comprising a programmable digital component for generating a 25 KHz square waveform signal, a current amplifier receiving the 25 KHz square waveform signal and injecting two identical control currents in the two sensing inductance coils, a differential amplifier for amplifying a voltage difference between the resulting voltages in the two sensing inductance coils and, depending on the displacement of the rotating shaft, an analog to digital (A/D) converter for delivering a position value from the voltage difference.
Claims10
A position detection device of active magnetic bearings maintaining the position of a rotating shaft and comprising two sensing inductance coils, wherein the position detection device further comprises:
- a programmable digital component for generating a 25 KHz square waveform signal,
- a current amplifier receiving the 25 KHz square waveform signal and injecting two identical control currents in the two sensing inductance coils,
- a differential amplifier for amplifying a voltage difference between the resulting voltages in the two sensing inductance coils and depending on the displacement of the rotating shaft, and
- an analog to digital (A/D) converter for delivering a position value from the voltage difference,
- wherein the position detection device is adapted to acquire resulting voltages in the two sensing inductance coils,
- wherein the position detection device is adapted to determine the voltage difference between the resulting voltages,
- wherein the position detection device is adapted to amplify the voltage difference between the resulting voltages in the differential amplifier,
- wherein the voltage difference for a positive displacement defines a positive curve,
- wherein the voltage difference for a negative displacement defines a negative curve,
- wherein the position detection device is adapted to convert the voltage difference in the A/D converter into a position value,
- which permits a synchronization of the conversion with the initial 25 KHz square waveform signal.
A position detection device of active magnetic bearings maintaining the position of a rotating shaft and comprising two sensing inductance coils, wherein the position detection device further comprises:
- a programmable digital component for generating a 25 KHz square waveform signal,
- a current amplifier receiving the 25 KHz square waveform signal and injecting two identical control currents in the two sensing inductance coils, two resistors connected in series with the two sensing inductance coils, and a Darlington transistor connected to the two resistors,
- a differential amplifier for amplifying a voltage difference between the resulting voltages in the two sensing inductance coils and depending on the displacement of the rotating shaft, and
- an analog to digital (A/D) converter for delivering a position value from the voltage difference,
- wherein the programmable digital component is integrated within one of a digital signal processor (DSP), a microcontroller or a field-programmable gate array (FGPA).
A position detection device of active magnetic bearings maintaining the position of a rotating shaft and comprising two sensing inductance coils, wherein the position detection device further comprises:
- a programmable digital component for generating a 25 KHz square waveform signal,
- a current amplifier receiving the 25 KHz square waveform signal and injecting two identical control currents in the two sensing inductance coils, two resistors connected in series with the two sensing inductance coils, and a Darlington transistor connected to the two resistors,
- a differential amplifier for amplifying a voltage difference between the resulting voltages in the two sensing inductance coils and depending on the displacement of the rotating shaft, and
- an analog to digital (A/D) converter for delivering a position value from the voltage difference,
- wherein the A/D converter is connected with the programmable digital component to synchronize the conversion with the 25 KHz square waveform signal for obtaining a position value corresponding to a maximal value of the voltage difference.
Dependencies are inferred from the claim text.