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EP-4467832-B1 - MAGNETIC BEARING CONTROL DEVICE, MAGNETIC BEARING DEVICE, AND TURBOMACHINERY

EP4467832B1EP 4467832 B1EP4467832 B1EP 4467832B1EP-4467832-B1

Inventors

  • FUJIMOTO SHUMPEI
  • SAKAWAKI ATSUSHI
  • HIBINO HIROSHI

Dates

Publication Date
20260513
Application Date
20240228

Claims (12)

  1. A magnetic bearing control device (90) for controlling a magnetic bearing device (10) including: a rotating body (A); a first magnetic bearing (B1) supporting the rotating body (A) in a first direction (D1), the first direction (D1) being one of an axial direction (X) or a radial direction (R) of the rotating body (A); a first protective bearing (C1) supporting the rotating body (A) in the first direction (D1) to reduce contact between the rotating body (A) and the first magnetic bearing (B 1); and a second protective bearing (C2) supporting the rotating body (A) in a second direction (D2), the second direction (D2) being the other one of the axial direction (X) or the radial direction (R) of the rotating body (A), wherein the first magnetic bearing (B1) receives a first current (J1) to make a first electromagnetic force (F1) act on the rotating body (A) in the first direction (D1), characterised in that at a position adjustment time (Q) at which a first-direction position (H1) of the rotating body (A) in the first direction (D1) with respect to the first protective bearing (C1) is adjusted before magnetic levitation control is performed on the rotating body (A), the magnetic bearing control device controls the first current (J1) to reduce a speed (U) of the rotating body (A) at a time of contact between the rotating body (A) and the first protective bearing (C1), wherein a first operation (M1) of supplying the first current (J1) of a predetermined value (J1v) and then stopping the supply of the first current (J1) and a second operation (M2) of increasing the predetermined value (J1v) when the first-direction position (H1) of the rotating body (A) does not change from that before the supply of the first current (J1) and decreasing the predetermined value (J1v) when the first-direction position (H1) of the rotating body (A) has changed from that before the supply of the first current (J1), are repeatedly executed.
  2. A magnetic bearing control device (90) for controlling a magnetic bearing device (10) including: a rotating body (A); a first magnetic bearing (B1) supporting the rotating body (A) in a first direction (D1), the first direction (D1) being one of an axial direction (X) or a radial direction (R) of the rotating body (A); a first protective bearing (C1) supporting the rotating body (A) in the first direction (D1) to reduce contact between the rotating body (A) and the first magnetic bearing (B 1); and a second protective bearing (C2) supporting the rotating body (A) in a second direction (D2), the second direction (D2) being the other one of the axial direction (X) or the radial direction (R) of the rotating body (A), wherein the first magnetic bearing (B1) receives a first current (J1) to make a first electromagnetic force (F1) act on the rotating body (A) in the first direction (D1), characterised in that at a position adjustment time (Q) at which a first-direction position (H1) of the rotating body (A) in the first direction (D1) with respect to the first protective bearing (C1) is adjusted before magnetic levitation control is performed on the rotating body (A), the magnetic bearing control device controls the first current (J1) to reduce a speed (U) of the rotating body (A) at a time of contact between the rotating body (A) and the first protective bearing (C1), wherein a third operation (M3) of increasing the first current (J1) until a change in the first-direction position (H1) of the rotating body (A) is detected and a fourth operation (M4) of reducing the first current (J1) to be in a range greater than zero after the change in the first-direction position (H1) of the rotating body (A) has been detected, are executed.
  3. The magnetic bearing control device of claim 2, wherein the fourth operation (M4) reduces the first current (J1) to a predetermined value (J1v) greater than zero.
  4. The magnetic bearing control device of claim 2 or 3, wherein the fourth operation (M4) reduces the first current (J1) such that the speed (U) of movement of the rotating body (A) in the first direction (D1) is constant.
  5. The magnetic bearing control device of any one of claims 1 to 4, wherein at the position adjustment time (Q), the first current (J1) is supplied at a current change rate (δa) smaller than a maximum current change rate (δ'a) of a case in which magnetic levitation control is performed on the rotating body (A).
  6. A magnetic bearing control device (90) for controlling a magnetic bearing device (10) including: a rotating body (A); a first magnetic bearing (B1) supporting the rotating body (A) in a first direction (D1), the first direction (D1) being one of an axial direction (X) or a radial direction (R) of the rotating body (A); a first protective bearing (C1) supporting the rotating body (A) in the first direction (D1) to reduce contact between the rotating body (A) and the first magnetic bearing (B 1); and a second protective bearing (C2) supporting the rotating body (A) in a second direction (D2), the second direction (D2) being the other one of the axial direction (X) or the radial direction (R) of the rotating body (A), wherein the first magnetic bearing (B1) receives a first current (J1) to make a first electromagnetic force (F1) act on the rotating body (A) in the first direction (D1), characterised in that at a position adjustment time (Q) at which a first-direction position (H1) of the rotating body (A) in the first direction (D1) with respect to the first protective bearing (C1) is adjusted before magnetic levitation control is performed on the rotating body (A), the magnetic bearing control device controls the first current (J1) to reduce a speed (U) of the rotating body (A) at a time of contact between the rotating body (A) and the first protective bearing (C1) , wherein the supply of the first current (J1) is stopped after a polarity of a first voltage (E1) to be applied to the first magnetic bearing (B1) is reversed.
  7. A magnetic bearing control device (90) for controlling a magnetic bearing device (10) including: a rotating body (A); a first magnetic bearing (B1) supporting the rotating body (A) in a first direction (D1), the first direction (D1) being one of an axial direction (X) or a radial direction (R) of the rotating body (A); a first protective bearing (C1) supporting the rotating body (A) in the first direction (D1) to reduce contact between the rotating body (A) and the first magnetic bearing (B 1); and a second protective bearing (C2) supporting the rotating body (A) in a second direction (D2), the second direction (D2) being the other one of the axial direction (X) or the radial direction (R) of the rotating body (A), wherein the first magnetic bearing (B1) receives a first current (J1) to make a first electromagnetic force (F1) act on the rotating body (A) in the first direction (D1), characterised in that at a position adjustment time (Q) at which a first-direction position (H1) of the rotating body (A) in the first direction (D1) with respect to the first protective bearing (C1) is adjusted before magnetic levitation control is performed on the rotating body (A), the magnetic bearing control device controls the first current (J1) to reduce a speed (U) of the rotating body (A) at a time of contact between the rotating body (A) and the first protective bearing (C1), , wherein the magnetic bearing device (10) includes a second magnetic bearing (B2) supporting the rotating body (A) in the second direction (D2), and the second magnetic bearing (B2) receives a second current (J2) to make a second electromagnetic force (F2) act on the rotating body (A) in the second direction (D2), the axis (0) of the shaft (20) extends in the horizontal direction, and the second current (J2) is supplied to the second magnetic bearing (B2) such that a normal force (N) of the second protective bearing (C2) acting on the rotating body (A) is in a range smaller than that of when the supply of the first current (J1) and the second current (J2) is stopped, and greater than zero.
  8. A magnetic bearing control device (90) for controlling a magnetic bearing device (10) including: a rotating body (A); a first magnetic bearing (B1) supporting the rotating body (A) in a first direction (D1), the first direction (D1) being one of an axial direction (X) or a radial direction (R) of the rotating body (A); a first protective bearing (C1) supporting the rotating body (A) in the first direction (D1) to reduce contact between the rotating body (A) and the first magnetic bearing (B 1); and a second protective bearing (C2) supporting the rotating body (A) in a second direction (D2), the second direction (D2) being the other one of the axial direction (X) or the radial direction (R) of the rotating body (A), wherein the first magnetic bearing (B1) receives a first current (J1) to make a first electromagnetic force (F1) act on the rotating body (A) in the first direction (D1), characterised in that at a position adjustment time (Q) at which a first-direction position (H1) of the rotating body (A) in the first direction (D1) with respect to the first protective bearing (C1) is adjusted before magnetic levitation control is performed on the rotating body (A), the magnetic bearing control device controls the first current (J1) to reduce a speed (U) of the rotating body (A) at a time of contact between the rotating body (A) and the first protective bearing (C1), the magnetic bearing device (10) includes a second magnetic bearing (B2) supporting the rotating body (A) in the second direction (D2), and the second magnetic bearing (B2) receives a second current (J2) to make a second electromagnetic force (F2) act on the rotating body (A) in the second direction (D2),the axis (0) of the shaft (20) extends in the horizontal direction, and the first current (J1) or the second current (J2) is supplied so as to vibrate the rotating body (A) in a circumferential direction (θ).
  9. The magnetic bearing control device of any one of claims 7 to 8, wherein the second current (J2) is supplied such that the normal force (N) of the second protective bearing (C2) acting on the rotating body (A) is greater than that of when the supply of the first current (J1) and the second current (J2) is stopped, after the first-direction position (H1) of the rotating body (A) is changed.
  10. The magnetic bearing control device of any one of claims 7 to 9, wherein the first direction (D1) is the axial direction (X); the second direction (D2) is the radial direction (R); the first magnetic bearing (B1) is a thrust magnetic bearing (50); and the second magnetic bearing (B2) is a radial magnetic bearing (40).
  11. A magnetic bearing device comprising the magnetic bearing control device (90) of any one of claims 1 to 10.
  12. A turbo machine comprising the magnetic bearing device (10) of claim 11.

Description

TECHNICAL FIELD The present disclosure relates to a magnetic bearing control device, a magnetic bearing device, and a turbo machine. BACKGROUND ART Patent Document 1 discloses a magnetic bearing device including a protective bearing (touchdown bearing). JP H03 139142 discloses a magnetic bearing control device according to the preamble of claims 1, 2, and 6-8. CITATION LIST PATENT DOCUMENT Patent Document 1: Japanese Unexamined Patent Publication No. 2019-173823 SUMMARY OF THE INVENTION TECHNICAL PROBLEM A protective bearing of a magnetic bearing device reduces contact between a magnetic bearing and a rotating body by coming into contact with the rotating body earlier than the magnetic bearing when the rotating body moves. In order that the protective bearing can function effectively, it is necessary to adjust a reference position of the rotating body with respect to the protective bearing. In general, before magnetic levitation control is performed on the rotating body, the position of the rotating body with respect to the protective bearing is adjusted while having the electromagnetic force of the magnetic bearing act on the rotating body. The electromagnetic force made to act on the rotating body by the magnetic bearing at a position adjustment of the rotating body with respect to the protective bearing may cause the rotating body to start moving with a great force and come into strong contact with the protective bearing, and the protective bearing and a component fixed thereto may be damaged. It is an object of the present disclosure to reduce, in a magnetic bearing device, damage of a protective bearing and a component fixed thereto at a position adjustment of a rotating body with respect to the protective bearing. SOLUTION TO THE PROBLEM The problems are solved by independent claims 1, 2, and 6-8. Dependent claims 3-5, and 9-12 provide preferred solutions. A first aspect of the present disclosure is directed to a magnetic bearing control device (90). The magnetic bearing control device (90) controls a magnetic bearing device (10). The magnetic bearing device (10) includes: rotating body (A); a first magnetic bearing (B1) supporting the rotating body (A) in a first direction (D1), the first direction (D1) being one of an axial direction (X) or a radial direction (R) of the rotating body (A); a first protective bearing (C1) supporting the rotating body (A) in the first direction (D1) to reduce contact between the rotating body (A) and the first magnetic bearing (B1); and a second protective bearing (C2) supporting the rotating body (A) in a second direction (D2), the second direction (D2) being the other one of the axial direction (X) or the radial direction (R) of the rotating body (A). The first magnetic bearing (B1) receives a first current (J1) to make a first electromagnetic force (F1) act on the rotating body (A) in the first direction (D1). At a position adjustment time (Q) at which a first-direction position (H1) of the rotating body (A) in the first direction (D1) with respect to the first protective bearing (C1) is adjusted, the magnetic bearing control device (90) controls the first current (J1) to reduce a speed (U) of the rotating body (A) at a time of contact between the rotating body (A) and the first protective bearing (C1). According to the first aspect, the magnetic bearing control device (90) reduces the speed (U) of the rotating body (A) at the time of contact between the rotating body (A) and the first protective bearing (C1) at the position adjustment time (Q) at which the first-direction position (H1) of the rotating body (A) with respect to the first protective bearing (C1) is adjusted. In the magnetic bearing device (10), it is possible to reduce damage of the first protective bearing (C1) and the component fixed thereto at the position adjustment time (Q) at which the first-direction position (H1) of the rotating body (A) with respect to the first protective bearing (C1) is adjusted. A second aspect of the present disclosure is an embodiment of the first aspect. In the second aspect, the magnetic bearing control device (90) repeatedly executes a first operation (M1) of supplying the first current (J1) of a predetermined value (J1v) and then stopping the supply of the first current (J1) and a second operation (M2) of increasing the predetermined value (J1v) when the first-direction position (H1) of the rotating body (A) does not change from that before the supply of the first current (J1) and decreasing the predetermined value (J1v) when the first-direction position (H1) of the rotating body (A) has changed from that before the supply of the first current (J1). According to the second aspect, the first operation (M1) and the second operation (M2) are repeatedly performed, so that the first-direction position (H1) of the rotating body (A) with respect to the first protective bearing (C1) changes in small steps. This is more advantageous in reducing the speed (U) of the rotating b