Multiple-axis magnetic bearing and control of the magnetic bearing with active switch topologies

Patent metadata

Field	Value
Publication number	US-9890811-B2
Application number	US-201314390197-A
Country	US
Kind code	B2
Filing date	Apr 3, 2013
Priority date	Apr 4, 2012
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A magnetic bearing system ( 120 ) includes a first active magnetic bearing (AMB) ( 202 ) including a first group of electromagnetic actuators ( 306, 310, 314, 318 ) to support a shaft and a second AMB ( 204 ) including a second group of electromagnetic actuators ( 308, 312, 316, 320 ) to support the shaft. A controller for the two AMB's includes a multi-phase topology ( 400 ) with a plurality of active current switches for controlling the electromagnetic actuators ( 306 - 320 ) of each of the first AMB ( 202 ) and the second AMB ( 204 ). Each electromagnetic actuator ( 306, 310, 314, 318 ) of the first AMB ( 202 ) is electrically coupled to an electromagnetic actuator ( 308, 312, 316, 320 ) of the second AMB ( 204 ). Each pair of coupled electromagnetic actuators ( 306, 316 ) is respectively connected to three phase legs ( 418, 420, 422 ) of the topology ( 400 ) of the controller, whereby one end (X 2 +, X 3 −) of each of the electromagnetic actuators of a pair ( 306, 316 ) is connected to one phase leg ( 420 ) of the topology ( 400 ) and the other ends (X 1 +, X 4 −) are respectively connected to two further phase legs ( 418, 422 ) of the topology ( 400 ). The controller is operable to receive information indicative of a position of the rotor shaft and supply an adjustment signal to the magnetic bearing system ( 120 ) to adjust the position of the shaft.

First claim

The invention claimed is:

1. A refrigerant vapor compression system including a condenser, an expansion valve, an evaporator, and a compressor coupled to a multiple-axis magnetic bearing system, comprising:
a motor operatively coupled to the compressor via a rotor shaft;
a position sensor to generate information indicative of a position of the rotor shaft;
the multiple-axis magnetic bearing system including a first active magnetic bearing (AMB) having a first group of electromagnetic actuators electrically coupled to a second AMB having a second group of electromagnetic actuators; and
a controller including a three-phase controlling circuit having a plurality of active current switches for controlling each of the first AMB and the second AMB;
wherein a first electromagnetic actuator of the first AMB is electrically coupled to a second electromagnetic actuator of the second AMB at a first phase leg, the first electromagnetic actuator coupled to a second phase leg and the second electromagnetic actuator coupled to a third phase leg of the controlling circuit;
wherein a third electromagnetic actuator of the first AMB is electrically coupled to a fourth electromagnetic actuator of the second AMB at a fourth phase leg, the third electromagnetic actuator coupled to a fifth phase leg and the fourth electromagnetic actuator coupled to a sixth phase leg of the controlling circuit; and
wherein the controller is operable to receive the information indicative of the position of the rotor shaft and supply an adjustment signal to the magnetic bearing system to adjust the position of the rotor shaft;
wherein the first group of electromagnetic actuators controls a position of the rotor shaft at a first location along a longitudinal length of the rotor shaft and the second group of electromagnetic actuators controls a position of the rotor shaft at a second location along the longitudinal length of the rotor shaft, the second position different from the first location.

2. The system of claim 1 , wherein the three-phase controlling circuit includes an active current switch coupled to at least one electromagnetic actuator from one of the first group of electromagnetic actuators or the second group of electromagnetic actuators.

3. The system of claim 1 , wherein the three-phase controlling circuit includes an active current switch electrically coupled in series to a diode and an electromagnetic actuator on a phase leg.

4. The system of claim 1 , wherein the three-phase controlling circuit includes two active current switches electrically coupled in series and an electromagnetic actuator on a phase leg.

5. The system of claim 1 , further comprising an active current switch receiving an exciting current for energizing the at least one electromagnetic actuator.

6. The system of claim 1 , further comprising an active current switch electrically connected a positive DC voltage level, a diode, and an electromagnetic actuator from the first group of electromagnetic actuators.

7. The system of claim 1 , wherein the controller is configured for energizing at least one electromagnetic actuator from one of the first group of electromagnetic actuators or the second group of electromagnetic actuators.

8. The system of claim 1 , wherein the controller is configured for controlling a bias current that is applied to at least one electromagnetic actuator of the first group of electromagnetic actuators or the second group of electromagnetic actuators.

9. The system of claim 8 , wherein the controller is configured for scaling the bias current.

10. A magnetic bearing system comprising:
a first active magnetic bearing (AMB) including a first group of electromagnetic actuators coupled to a shaft;
a second active magnetic bearing (AMB) including a second group of electromagnetic actuators coupled to the shaft;
a position sensor to generate information indicative of a position of the rotor shaft;
a controller including a three-phase controlling circuit having a plurality of active current switches for controlling each of the first AMB and the second AMB;
wherein a first electromagnetic actuator of the first AMB is electrically coupled to a second electromagnetic actuator of the second AMB at a first phase leg, the first electromagnetic actuator coupled to a second phase leg and the second electromagnetic actuator coupled to a third phase leg of the controlling circuit;
wherein a third electromagnetic actuator of the first AMB is electrically coupled to a fourth electromagnetic actuator of the second AMB at a fourth phase leg, the third electromagnetic actuator coupled to a fifth phase leg and the fourth electromagnetic actuator coupled to a sixth phase leg of the controlling circuit; and
wherein the controller is operable to receive the information indicative of the position of the rotor shaft and supply an adjustment signal to the magnetic bearing system to adjust the position of the shaft;
wherein the first group of electromagnetic actuators controls a position of the rotor shaft at a first location along a longitudinal length of the rotor shaft and the second group of electromagnetic actuators controls a position of the rotor shaft at a second location along the longitudinal length of the rotor shaft, the second location different from the first location.

11. The system of claim 10 , wherein the three-phase controlling circuit includes an active current switch coupled to at least one electromagnetic actuator from one of the first group of electromagnetic actuators or the second group of electromagnetic actuators.

12. The system of claim 10 , wherein the three-phase controlling circuit includes an active current switch electrically coupled in series to a diode and an electromagnetic actuator on a phase leg.

13. The system of claim 10 , wherein the three-phase controlling circuit includes two active current switches electrically coupled in series and an electromagnetic actuator on a phase leg.

14. The system of claim 10 , further comprising an active current switch receiving an exciting current for energizing the at least one electromagnetic actuator.

15. The system of claim 10 , further comprising an active current switch electrically connected a positive DC voltage level, a diode, and an electromagnetic actuator from the first group.

16. The system of claim 10 , wherein the controller is configured for energizing at least one electromagnetic actuator from one of the first group of electromagnetic actuators or the second group of electromagnetic actuators.

17. The system of claim 10 , wherein the controller is configured for controlling a bias current that is applied to at least one electromagnetic actuator of the first group of electromagnetic actuators or the second group of electromagnetic actuators.

18. The system of claim 17 , wherein the controller is configured for scaling the bias current.

19. A method for controlling a rotor shaft that operatively connects a compressor to a motor in a vapor compression system, comprising:
receiving information indicative of a first position of a first active magnetic bearing (AMB), the first AMB includes a first group of electromagnetic actuators being coupled to the rotor shaft at the first position;
receiving information indicative of a second position of a second AMB, the second AMB includes a second group of electromagnetic actuators being coupled to the rotor shaft at the second position; and
providing a controller in electrical communication with each of the first AMB and the second AMB; and
the controller generating

Assignees

• Carrier Corp

Inventors

• Kshirsagar Parag
• Yan Peng

Classifications

• F16C32/0451

  Details of controllers, i.e. the units determining the power to be supplied, e.g. comparing elements, feedback arrangements with P.I.D. control · CPC title

• F16C32/0457 Primary

  Details of the power supply to the electromagnets · CPC title

• F16C32/0487

  with active support of four degrees of freedom · CPC title

• F16C2362/52

  Compressors of refrigerators, e.g. air-conditioners · CPC title

• F16C32/0489 Primary

  with active support of five degrees of freedom, e.g. two radial magnetic bearings combined with an axial bearing · CPC title