Magnetic bearing system, compressor, and refrigeration device

Abstract

To suppress cost of an inverter in a magnetic bearing system.SOLUTION: A magnetic bearing system (100) comprises a rotational shaft (101) and magnetic bearings (105, 107, 130) having electromagnet coils (106, 108, 108B, 135, 136). One end of the electromagnet coils (106, 108, 108B, 135, 136) is connected to a neutral point of a first polyphase windings (113, 115, 123, 125, 173, 181) having at least three phases.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a magnetic bearing system, a compressor, and a refrigeration device. [Background technology]

[0002] A five-axis controlled magnetic bearing system that actively controls the positioning of all the movements of a rotating shaft is known (Patent Document 1). The five-axis controlled magnetic bearing system is provided with a motor that rotates the rotating shaft in the circumferential direction, a thrust magnetic bearing that controls the axial position of the rotating shaft, and a radial magnetic bearing that controls the radial position of the rotating shaft.

[0003] In conventional 5-axis controlled magnetic bearing systems, the thrust magnetic bearing can generate electromagnetic force in the axial direction, and is composed of two units: a front thrust magnetic bearing that generates electromagnetic force in one axial direction, and a rear thrust magnetic bearing that generates electromagnetic force in the other axial direction, and one inverter composed of multiple switching elements is used for the front and rear thrust support coils. One radial magnetic bearing is placed on each of the front and rear sides. Separate inverters are placed for each radial magnetic bearing and motor coil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2001-041236 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a back-to-back magnetic bearing system, a bearingless motor may be placed on the front and rear instead of the motor and two radial magnetic bearings. In this case, one inverter is required for the motor drive coil of each bearingless motor, and one PWM inverter is required for the radial support coil of each bearingless motor.

[0006] As described above, in conventional magnetic bearing systems, it is necessary to provide a large number of inverters, which inevitably increases the cost of the product.

[0007] An object of the present disclosure is to make it possible to reduce the cost of inverters in magnetic bearing systems. [Means for solving the problem]

[0008] A first aspect of the present disclosure is a magnetic bearing system (100) comprising a rotating shaft (101) and a magnetic bearing (105, 107, 130) having an electromagnet coil (106, 108, 108B, 135, 136), one end of which is connected to a neutral point of a first polyphase winding (113, 115, 123, 125, 173, 181) having at least three phases.

[0009] In the first aspect, the voltage applied to one end of the electromagnet coil (106, 108, 108B, 135, 136) of the magnetic bearing (105, 107, 130) can be adjusted by adjusting the current of the first multi-phase winding (113, 115, 123, 125, 173, 181). Therefore, it is not necessary to provide a dedicated switching element for adjusting the voltage at one end of the electromagnet coil (106, 108, 108B, 135, 136) of the magnetic bearing (105, 107, 130), and therefore the cost of the inverter can be reduced.

[0010] A second aspect of the present disclosure is characterized in that, in the first aspect, the other end of the electromagnet coil (106, 108, 108B, 135, 136) is connected to a neutral point or an end of a second polyphase winding (113, 115, 123, 125, 173, 181) having at least three phases different from the first polyphase winding (113, 115, 123, 125, 173, 181).

[0011] In the second aspect, the voltage applied to the other end of the electromagnet coil (106, 108, 108B, 135, 136) of the magnetic bearing (105, 107, 130) can be adjusted by adjusting the current of the second multi-phase winding (113, 115, 123, 125, 173, 181). Therefore, it is not necessary to provide a dedicated switching element for voltage adjustment at both ends of the electromagnet coil (106, 108, 108B, 135, 136) of the magnetic bearing (105, 107, 130). This makes it possible to further reduce the cost of the inverter.

[0012] A third aspect of the present disclosure is a bearingless motor (110, 120) in the second aspect, further comprising a motor winding (115, 125) that generates a rotational torque on the rotating shaft (101) when power is supplied thereto, and a radial support winding (113, 123) that generates an axial support force that supports the rotating shaft (101) non-contact when power is supplied thereto, wherein the first polyphase winding (113, 115, 123, 125, 173, 181) is one of the motor winding (115, 125) and the radial support winding (113, 123), and the second polyphase winding (113, 115, 123, 125, 173, 181) is the other of the motor winding (115, 125) and the radial support winding (113, 123).

[0013] In the third aspect, the electromagnet coils (106, 108, 108B, 135, 136) of the magnetic bearings (105, 107, 130) can be operated using one bearingless motor (110, 120) without adding any switching elements.

[0014] A fourth aspect of the present disclosure is the third aspect, wherein the radial support winding (113, 123) is wound using short-pitch winding, and the winding pitch of the radial support winding (113, 123) is equal to or greater than half the number of slots of each pole of the radial support winding (113, 123).

[0015] In the fourth aspect, when a zero-phase-sequence current is passed through the radial support windings (113, 123), the effect of the zero-phase-sequence current on the axial support force of the radial support windings (113, 123) can be suppressed, making it easier to control the bearingless motors (110, 120).

[0016] A fifth aspect of the present disclosure relates to a first bearingless motor (110) in the second aspect, the first bearingless motor (110) having a first motor winding (115) that generates a rotational torque on the rotating shaft (101) when power is supplied thereto, and a first radial support winding (113) that generates a shaft supporting force for supporting the rotating shaft (101) in a non-contact manner when power is supplied thereto, a second motor winding (125) that generates a rotational torque on the rotating shaft (101) when power is supplied thereto, and a second radial support winding (113) that generates a shaft supporting force for supporting the rotating shaft (101) in a non-contact manner when power is supplied thereto. and a second bearingless motor (120) having a second radial support winding (123) that generates a axial support force to support the rotor, the first polyphase winding (113, 115, 123, 125, 173, 181) being one of the first motor winding (115) and the first radial support winding (113), and the second polyphase winding (113, 115, 123, 125, 173, 181) being one of the second motor winding (125) and the second radial support winding (123).

[0017] In the fifth aspect, the electromagnet coils (106, 108, 108B) of the magnetic bearings (105, 107) can be operated using two bearingless motors (110, 120) without adding any switching elements.

[0018] A sixth aspect of the present disclosure is directed to the fifth aspect, in which at least one of the first radial support winding (113) and the second radial support winding (123), is wound using short-pitch winding, and the winding pitch of the radial support winding (113, 123) is equal to or greater than half the number of slots of each pole of the radial support winding (113, 123).

[0019] In the sixth aspect, when a zero-phase-sequence current is passed through the radial support windings (113, 123), the effect of the zero-phase-sequence current on the axial support force of the radial support windings (113, 123) can be suppressed, making it easier to control the bearingless motors (110, 120).

[0020] A seventh aspect of the present disclosure is any one of the first to sixth aspects, wherein the electromagnet coil (106, 108, 108B, 135, 136) and the first polyphase winding (113, 115, 123, 125, 173) are arranged in the same pressure vessel (150), and the one end of the electromagnet coil (106, 108, 108B, 135, 136) is connected to the neutral point of the first polyphase winding (113, 115, 123, 125, 173) within the pressure vessel (150).

[0021] In the seventh aspect, there is no need to provide a dedicated airtight terminal for electrically connecting the inside and outside of the pressure vessel (150) in order to apply a voltage to one end of the electromagnet coil (106, 108, 108B, 135, 136) of the magnetic bearing (105, 107, 130). This not only reduces the cost of the inverter, but also the cost of the airtight terminal.

[0022] An eighth aspect of the present disclosure is any one of the first to seventh aspects, further comprising other electromagnet coils (106, 108, 108A, 135, 137) that generate, on the rotating shaft (101), an electromagnetic force in the same direction or an opposite direction as the electromagnetic force generated on the rotating shaft (101) when current is passed through the electromagnet coils (106, 108, 108B, 136, and is configured such that the control band of the electromagnet coils (106, 108, 108B, 136) is lower than the control band of the other electromagnet coils (106, 108, 108A, 135, 137).

[0023] In the eighth aspect, the control band of the electromagnet coils (106, 108, 108B, 136) of the magnetic bearings (105, 107, 130) is set low, so that the switching frequency of the electromagnet coils (106, 108, 108B, 136) can be lowered, and switching losses can be suppressed.

[0024] A ninth aspect of the present disclosure is the eighth aspect, further comprising another magnetic bearing (105, 107) having the other electromagnet coil (106, 108), wherein a bias current is supplied to the electromagnet coil (106, 108), and the direction of an axial electromagnetic force generated with respect to the rotating shaft (101) by passing current through the electromagnet coil (106, 108) is opposite to the direction of an axial electromagnetic force generated with respect to the rotating shaft (101) by passing current through the other electromagnet coil (106, 108).

[0025] In the ninth aspect, the switching frequency of the electromagnet coils (106, 108) of the magnetic bearings (105, 107, 130) can be lowered, and loss due to switching can be suppressed.

[0026] A tenth aspect of the present disclosure is the eighth aspect, wherein the other electromagnet coil (108A, 137) is provided in the magnetic bearing (107, 130), a bias current is supplied to the electromagnet coil (108B, 136), and the direction of an electromagnetic force generated on the rotating shaft (101) by passing current through the electromagnet coil (108B, 136) is the same as the direction of an electromagnetic force generated on the rotating shaft (101) by passing current through the other electromagnet coil (108A, 137).

[0027] In the tenth aspect, the switching frequency of the electromagnet coils (108B, 136) of the magnetic bearings (105, 107, 130) can be lowered, and loss due to switching can be suppressed.

[0028] An eleventh aspect of the present disclosure is any one of the first to tenth aspects, wherein the magnetic bearing (105, 107, 130) is a thrust magnetic bearing or a radial magnetic bearing.

[0029] In the eleventh aspect, in a magnetic bearing system (100) having a thrust magnetic bearing or a radial magnetic bearing, the cost of an inverter can be suppressed.

[0030] A twelfth aspect of the present disclosure is a compressor including the magnetic bearing system (100) according to any one of the first to eleventh aspects.

[0031] In the twelfth aspect, since the cost of the inverter in the magnetic bearing system (100) constituting the compressor (10) can be reduced, the compressor (10) can be manufactured at low cost.

[0032] A thirteenth aspect of the present disclosure is a refrigeration apparatus including the compressor (10) of the twelfth aspect.

[0033] In the thirteenth aspect, in the magnetic bearing system (100) constituting the compressor (10) used in the refrigeration apparatus, the cost of the inverter can be reduced, and therefore the refrigeration apparatus can be manufactured at low cost. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a schematic diagram of a compressor equipped with a magnetic bearing system according to a first embodiment. [Diagram 2] FIG. 2 is a diagram showing a circuit configuration of the magnetic bearing system of the first embodiment. [Diagram 3] FIG. 3 is a diagram showing a circuit configuration of the magnetic bearing system of the first embodiment. [Figure 4] FIG. 4 is a diagram showing a circuit configuration of a magnetic bearing system according to a first modified example of the first embodiment. [Diagram 5] FIG. 5 is a diagram showing a circuit configuration of a magnetic bearing system according to a first modified example of the first embodiment. [Figure 6] FIG. 6 is a diagram showing a circuit configuration of a magnetic bearing system according to a second modified example of the first embodiment. [Figure 7] FIG. 7 is a diagram showing a circuit configuration of a magnetic bearing system according to a second modified example of the first embodiment. [Figure 8] FIG. 8 is a schematic diagram of a compressor equipped with a magnetic bearing system according to the second embodiment. [Figure 9] FIG. 9 is a diagram showing a circuit configuration of a magnetic bearing system according to the second embodiment. [Figure 10] FIG. 10 is a schematic diagram of a compressor equipped with a magnetic bearing system according to a first modified example of the second embodiment. [Figure 11] FIG. 11 is a diagram showing a circuit configuration of a magnetic bearing system according to a first modified example of the second embodiment. [Figure 12] FIG. 12 is a diagram showing a circuit configuration of a magnetic bearing system according to a second modified example of the second embodiment. [Figure 13] FIG. 13 is a diagram showing a circuit configuration of a magnetic bearing system according to a second modified example of the second embodiment. [Figure 14] FIG. 14 is a schematic diagram of a compressor equipped with a magnetic bearing system according to a third modified example of the second embodiment. [Figure 15]FIG. 15 is a diagram showing a circuit configuration of a magnetic bearing system according to a third modified example of the second embodiment. [Figure 16] FIG. 16 is a diagram showing a circuit configuration of a magnetic bearing system according to a third modified example of the second embodiment. [Figure 17] FIG. 17 is a schematic diagram showing a cross section perpendicular to the axial direction of a radial magnetic bearing provided in the magnetic bearing system of the third embodiment. [Figure 18] FIG. 18 is a diagram showing a circuit configuration of a magnetic bearing system according to the third embodiment. [Figure 19] FIG. 19 is a schematic diagram showing a cross section perpendicular to the axial direction of a radial magnetic bearing provided in a magnetic bearing system according to a modified example of the third embodiment. [Figure 20] FIG. 20 is a schematic diagram showing a cross section perpendicular to the axial direction of a CPM motor. [Figure 21] FIG. 21 is a diagram showing a motor winding arrangement of the CPM motor shown in FIG. [Figure 22] FIG. 22 is a diagram showing a supporting winding arrangement of the CPM motor shown in FIG. [Figure 23] FIG. 23 is a diagram showing the supporting force interference angle in the CPM motor shown in FIG. [Figure 24] FIG. 24 is a diagram showing the influence of a zero-phase current on the supporting force in the x-axis direction, the supporting force in the y-axis direction, and the supporting force interference angle in the CPM motor shown in FIG. [Diagram 25] FIG. 25 is a diagram showing changes in the primary, tertiary and quintic support winding coefficients with respect to the winding pitch in the CPM motor shown in FIG. [Figure 26] FIG. 26 is a diagram showing the arrangement of support windings of a CPM motor that constitutes the magnetic bearing system of the fourth embodiment. [Figure 27] FIG. 27 is a diagram showing the influence of a zero-phase current on the supporting force and the supporting force interference angle in the x-axis direction in a CPM motor constituting the magnetic bearing system of the fourth embodiment. [Figure 28] FIG. 28 is a schematic diagram showing a cross section perpendicular to the axial direction of an SPM motor. [Figure 29] FIG. 29 is a diagram showing a motor winding arrangement of the SPM motor shown in FIG. [Diagram 30] FIG. 30 is a diagram showing a supporting winding arrangement of the SPM motor shown in FIG. [Diagram 31] FIG. 31 is a diagram showing the influence of a zero-phase current on the supporting force in the x-axis direction, the supporting force in the y-axis direction, and the supporting force interference angle in the SPM motor shown in FIG. [Diagram 32] FIG. 32 is a diagram showing a support winding arrangement of an SPM motor that constitutes a magnetic bearing system according to a modified example of the fourth embodiment. [Diagram 33] FIG. 33 is a diagram showing the influence of zero-phase current on the supporting force in the x-axis direction, the supporting force in the y-axis direction, and the supporting force interference angle in an SPM motor constituting a magnetic bearing system according to a modified example of the fourth embodiment. [Diagram 34] FIG. 34 is a schematic configuration diagram of an air conditioner (an example of a refrigeration device) of the fifth embodiment. [Diagram 35] FIG. 35 is a diagram showing a circuit configuration of a first example of a magnetic bearing system according to another embodiment. [Diagram 36] FIGS. 36(a) and 36(b) are diagrams showing circuit configurations of a second example and a third example of a magnetic bearing system according to other embodiments, respectively. [Figure 37] FIG. 37 is a schematic diagram of a compressor equipped with a fourth example of a magnetic bearing system according to another embodiment. [Figure 38] FIG. 38 is a schematic diagram of a compressor equipped with a fifth example of a magnetic bearing system according to another embodiment. [Figure 39] FIG. 39 is a diagram showing a circuit configuration of a fifth example of a magnetic bearing system according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. In addition, in the drawings, the same reference numerals represent the same components, but the dimensions in the drawings, such as length, width, thickness, and depth, are appropriately changed from the actual scale for clarity and simplification of the drawings, and may not correspond to the actual relative dimensions.

[0036] (First embodiment) <Magnetic bearing system configuration> The following describes, as an example, a compressor (10) in which the magnetic bearing system (100) of the first embodiment is provided inside a pressure vessel (150); however, the use of the magnetic bearing system (100) is not particularly limited.

[0037] 1, the magnetic bearing system (100) mainly includes a rotating shaft (101), thrust magnetic bearings (105, 107), and bearingless motors (110, 120). In the following description, a direction along the axis of the rotating shaft (101) is referred to as an axial direction, a direction along a circle centered on the rotating shaft (101) is referred to as a circumferential direction, and a direction perpendicular to the axis of the rotating shaft (101) is referred to as a radial direction.

[0038] Impellers (102, 103) constituting a compression mechanism of the compressor (10) are provided at both axial ends of the rotating shaft (101). Specifically, a first impeller (102) is provided at the front end of the rotating shaft (101), and a second impeller (103) is provided at the rear end of the rotating shaft (101). That is, the magnetic bearing system (100) is of a back-to-back type. Note that, in FIG. 1, elements such as piping constituting the compression mechanism, a control unit, and the like are not shown.

[0039] The thrust magnetic bearings (105, 107) are configured to apply electromagnetic force to the drive shaft (101) in both axial directions. Specifically, a disk portion (104) extending in the radial direction is provided in the axial center of the rotating shaft (101), and a first thrust magnetic bearing (105) that generates an axial electromagnetic force is disposed on the front side of the disk portion (104), and a second thrust magnetic bearing (107) that generates an axial electromagnetic force is disposed on the rear side. This allows the thrust magnetic bearings (105, 107) to support the disk portion (104) in a non-contact manner by electromagnetic force.

[0040] The first thrust magnetic bearing (105) has a first electromagnet coil (106). The second thrust magnetic bearing (107) has a second electromagnet coil (108). The thrust magnetic bearings (105, 107) can control the position of the disk portion (104), i.e., the position of the drive shaft (101), by controlling the current flowing through the first and second electromagnet coils (106, 108).

[0041] The bearingless motors (110, 120) are configured to rotate the drive shaft (101) by electromagnetic force and to support the radial load of the drive shaft (101) in a non-contact manner. Specifically, the first bearingless motor (110) is disposed between the first impeller (102) and the first thrust magnetic bearing (105) of the rotating shaft (101), and the second bearingless motor (120) is disposed between the second impeller (103) and the second thrust magnetic bearing (105) of the rotating shaft (101).

[0042] The first bearingless motor (110) has a first rotor (111) and a first stator (112). The first rotor (111) is fixed to the drive shaft (101). The first stator (112) is fixed to an inner peripheral wall of the pressure vessel (150). A plurality of permanent magnets (not shown) are embedded in a core portion of the first rotor (111). The first stator (112) has a plurality of teeth portions (not shown), and a first radial support winding (113) and a first motor winding (115) are wound around each of the teeth portions. The first radial support winding (113) generates a shaft supporting force for supporting the rotating shaft (101) in a non-contact manner when power is supplied to the first motor winding (115). When power is supplied to the first motor winding (115), a rotational torque is generated in the rotating shaft (101). Each of the first radial support winding (113) and the first motor winding (115) is a multi-phase winding having three or more phases (in this example, a three-phase winding having a U-phase, a V-phase, and a W-phase).

[0043] The second bearingless motor (120) has a second rotor (121) and a second stator (122). The second rotor (121) is fixed to the drive shaft (101). The second stator (122) is fixed to an inner peripheral wall of the pressure vessel (150). A plurality of permanent magnets (not shown) are embedded in a core portion of the second rotor (121). The second stator (122) has a plurality of teeth portions (not shown), and a second radial support winding (123) and a second motor winding (125) are wound around each of the teeth portions. The second radial support winding (123) generates a shaft supporting force for supporting the rotating shaft (101) in a non-contact manner when power is supplied to the second motor winding (125). When power is supplied to the second motor winding (125), a rotational torque is generated in the rotating shaft (101). Each of the second radial support winding (123) and the second motor winding (125) is a multi-phase winding having three or more phases (in this example, a three-phase winding having a U-phase, a V-phase, and a W-phase).

[0044] <Circuit for magnetic bearing system> As shown in Fig. 2, the first radial support winding (113) of the first bearingless motor (110) is supplied with power from a first inverter (114), and the first motor winding (115) of the first bearingless motor (110) is supplied with power from a second inverter (116). The inverters (114, 116) may be, for example, PWM (Pulse Width Modulation) inverters configured using switching elements. The inverters (114, 116) are electrically disposed outside the pressure vessel (150) and connected to the windings (113, 115) via dedicated airtight terminals that electrically connect the inside and outside of the pressure vessel (150). The inverters (114, 116) convert an input direct current to generate a three-phase alternating current to be supplied to the windings (113, 115).

[0045] In the first radial support winding (113), one end of each of the U-phase, V-phase, and W-phase windings is connected at a neutral point. The first inverter (114) supplies a voltage V ur1 is applied to the other end of the V-phase winding, and a voltage V vr1 is applied to the other end of the W-phase winding, and a voltage V wr1 This causes the radial support current i ur1 flows in the V-phase winding, and the radial support current i vr1 flows in the W-phase winding, and the radial support current i wr1 flows.

[0046] In the first motor winding (115), one end of each of the U-phase, V-phase, and W-phase windings is connected at a neutral point. The second inverter (116) supplies a voltage V um1 is applied to the other end of the V-phase winding, and a voltage V vm1 is applied to the other end of the W-phase winding, and a voltage V wm1 This causes the motor drive current i um1 flows in the V-phase winding, and the motor drive current i vm1 flows through the W-phase winding, and the motor drive current i wm1 flows.

[0047] In the magnetic bearing system (100) of the present embodiment, one end of the first electromagnet coil (106) of the first thrust magnetic bearing (105) is connected to the neutral point of the first radial support winding (113) within the pressure vessel (150), and the other end of the first electromagnet coil (106) is connected to the neutral point of the first motor winding (115) within the pressure vessel (150).

[0048] As a result, a predetermined support current i is supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105). zf When trying to pass the radial support current, in addition to the original radial support current, i zf / 3, the first electromagnet coil (106) will have a supporting current i zf can be passed as a zero-phase current. zf After flowing through the first electromagnet coil (106), the radial support current (i ur1 , i vr1 , i wr1 ) amplitude of I r1 , the phase is φ1, and the motor drive current (i um1 , i vm1 , i wm1 ) amplitude of I m1 , with phase β1, i ur1 =I r1 sin(φ1)+i zf / 3 i vr1 =I r1 sin(φ1+2π / 3)+i zf / 3 i wr1 =I r1 sin(φ1+4π / 3)+i zf / 3 i um1 =I m1 sin(β1)-i zf / 3 i vm1 =I m1 sin(β1+2π / 3)-i zf / 3 i wm1 =I m1 sin(β1+4π / 3)-izf / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined support current i can be supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) without adding any switching element. zf can be flushed.

[0049] As shown in Fig. 3, the second radial support winding (123) of the second bearingless motor (120) is supplied with power from a third inverter (124), and the second motor winding (125) of the second bearingless motor (120) is supplied with power from a fourth inverter (126). The inverters (124, 126) are formed using, for example, switching elements. The inverters (124, 126) are disposed outside the pressure vessel (150) and connected to the windings (123, 125) via dedicated airtight terminals that electrically connect the inside and outside of the pressure vessel (150). The inverters (124, 126) convert an input direct current to generate a three-phase alternating current to be supplied to the windings (123, 125).

[0050] In the second radial support winding (123), one end of each of the U-phase, V-phase, and W-phase windings is connected to a neutral point. The third inverter (124) supplies a voltage V ur2 is applied to the other end of the V-phase winding, and a voltage V vr2 is applied to the other end of the W-phase winding, and a voltage V wr2 This causes the radial support current i ur2 flows in the V-phase winding, and the radial support current i vr2 flows in the W-phase winding, and the radial support current i wr2 flows.

[0051] In the second motor winding (125), one end of each of the U-phase, V-phase, and W-phase windings is connected at a neutral point. The fourth inverter (126) supplies a voltage V um2 is applied to the other end of the V-phase winding, and a voltage V vm2 is applied to the other end of the W-phase winding, and a voltage V wm2 This causes the motor drive current i um2flows in the V-phase winding, and the motor drive current i vm2 flows through the W-phase winding, and the motor drive current i wm2 flows.

[0052] In the magnetic bearing system (100) of the present embodiment, one end of the second electromagnet coil (108) of the second thrust magnetic bearing (107) is connected to the neutral point of the second radial support winding (123) within the pressure vessel (150), and the other end of the second electromagnet coil (108) is connected to the neutral point of the second motor winding (125) within the pressure vessel (150).

[0053] As a result, a predetermined supporting current i is supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (107). zr When trying to pass the current, in addition to the original radial support current, i zr / 3, the second electromagnet coil (108) will have a supporting current i zr can be passed as a zero-phase current. zr After flowing through the second electromagnet coil (108), the radial support current (i ur2 , i vr2 , i wr2 ) amplitude of I r2 , the phase is φ2, and the motor drive current (i um2 , i vm2 , i wm2 ) amplitude of I m2 , with phase β2, i ur2 =I r2 sin(φ2) + i zr / 3 i vr2 =I r2 sin(φ2+2π / 3)+i zr / 3 i wr2 =I r2 sin(φ2+4π / 3)+i zr / 3 i um2 =I m2 sin(β2)-i zr / 3 i vm2=I m2 sin(β2+2π / 3)-i zr / 3 i wm2 =I m2 sin(β2+4π / 3)-i zr / 3 If the inverters (124, 126) are controlled so as to satisfy the above condition, a predetermined supporting current i can be supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (107) without adding any switching element. zr can be flushed.

[0054] In the example shown in FIG. 2 and FIG. 3, a support current i zf , i zr However, the inverters (114, 116) and the inverters (124, 126) control the voltages of the radial support windings (113, 123) and the motor windings (115, 125), so that the support current i zf , i zr The direction of flow and supporting current i zf , i zr The size of the can be adjusted.

[0055] <Features of the embodiment> As described above, in this embodiment, one end of the electromagnet coil (106, 108) of the thrust magnetic bearing (105, 107) is connected to the neutral point of the radial support winding (113, 123) which is a multi-phase winding having three or more phases. Therefore, by adjusting the current of the radial support winding (113, 123), it is possible to adjust the voltage applied to one end of the electromagnet coil (106, 108) of the thrust magnetic bearing (105, 107). In addition, the other end of the electromagnet coil (106, 108) of the thrust magnetic bearing (105, 107) is connected to the neutral point of the motor winding (115, 125) which is a multi-phase winding having three or more phases. Therefore, by adjusting the current of the motor winding (115, 125), it is possible to adjust the voltage applied to the other end of the electromagnet coil (106, 108) of the thrust magnetic bearing (105, 107). This eliminates the need to provide dedicated switching elements for voltage adjustment at both ends of the electromagnet coils (106, 108) of the magnetic bearings (105, 107).In other words, it is not necessary to provide an inverter for the thrust magnetic bearings (105, 107), which makes it possible to reduce the cost of the inverter.

[0056] In this embodiment, one end of the first electromagnet coil (106) of the first thrust magnetic bearing (105) is connected to a neutral point of the first radial support winding (113) of the first bearingless motor (110), and the other end of the first electromagnet coil (106) is connected to a neutral point of the first motor winding (115) of the first bearingless motor (110). Therefore, the first electromagnet coil (106) of the first thrust magnetic bearing (105) can be operated using a single first bearingless motor (110) without adding a switching element.

[0057] In the present embodiment, one end of the second electromagnet coil (108) of the second thrust magnetic bearing (107) is connected to a neutral point of the second radial support winding (123) of the second bearingless motor (120), and the other end of the second electromagnet coil (108) is connected to a neutral point of the second motor winding (125) of the second bearingless motor (120). Therefore, the second electromagnet coil (108) of the second thrust magnetic bearing (107) can be operated using a single second bearingless motor (120) without adding a switching element.

[0058] In this embodiment, one end of the electromagnet coils (106, 108) of the thrust magnetic bearings (105, 107) is connected to the neutral point of the radial support windings (113, 123) inside the pressure vessel (150), and the other end of the electromagnet coils (106, 108) is connected to the neutral point of the motor windings (115, 125) inside the pressure vessel (150). This eliminates the need to provide a dedicated airtight terminal for electrically connecting the inside and outside of the pressure vessel (150) in order to apply a voltage to the electromagnet coils (106, 108) of the thrust magnetic bearings (105, 107), thereby reducing not only the cost of the inverter but also the cost of the airtight terminals.

[0059] In the compressor (10) including the magnetic bearing system (100) of this embodiment, the cost of the inverter can be reduced, and therefore the compressor (10) can be manufactured at low cost.

[0060] (First Modification of the First Embodiment) This modified example differs from the first embodiment in that, as shown in FIG. 4, the neutral point of one motor winding (first motor winding (115) or second motor winding (125)) is connected to the neutral point of each of two radial support windings (first radial support winding (113) and second radial support winding (123)) via the first electromagnet coil (106) of the first thrust magnetic bearing (105) or the second electromagnet coil (108) of the second thrust magnetic bearing (107). Note that in FIG. 4, elements that are the same as those in the first embodiment shown in FIGS. 2 and 3 are denoted by the same reference symbols.

[0061] In this modification, a predetermined support current i is supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105). zf When trying to pass the radial support current, in addition to the original radial support current, i zf / 3, the first electromagnet coil (106) will have a supporting current i zf In addition, a predetermined support current i can be supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (107). zr When trying to pass the current, in addition to the original radial support current, i zr / 3, the second electromagnet coil (108) will have a supporting current i zr can be flowed as a zero-phase current.

[0062] Zero-sequence current i zf , i zr are the currents i that flow through the first electromagnet coil (106) and the second electromagnet coil (108) and are then added together. z flows into the first motor winding (115) or the second motor winding (125). Therefore, the radial support current (i ur1 , i vr1 , i wr1 ) amplitude of I r1 , the phase is φ1, and the radial support current (i ur2 , i vr2 , i wr2 ) amplitude of I r2 , the phase is φ2, and the motor drive current (i um1 , i vm1 , i wm1 ) amplitude of I m1 , with phase β1, i ur1 =I r1 sin(φ1)+i zf / 3 i vr1 =I r1 sin(φ1+2π / 3)+i zf / 3 i wr1 =I r1 sin(φ1+4π / 3)+i zf / 3 i ur2 =I r2 sin(φ2) + i zr / 3 i vr2 =I r2 sin(φ2+2π / 3)+i zr / 3 i wr2 =I r2 sin(φ2+4π / 3)+i zr / 3 i um1 =I m1 sin(β1)-i z i vm1 =I m1 sin(β1+2π / 3)-i z i wm1 =I m1 sin(β1+4π / 3)-i z (However, z =i zf +i zr ) If the inverters (114, 116, 124, 126) are controlled so as to satisfy the above condition, a predetermined support current i can be supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) without adding any switching element. zf and a predetermined supporting current i can be supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (107). zr can be flushed.

[0063] As described above, in this modified example, by using two bearingless motors (110, 120) and operating the electromagnet coils (106, 108) of the two magnetic bearings (105, 107), respectively, without adding switching elements, it is possible to obtain the same effects as in the first embodiment.

[0064] In this modification, the neutral point of one motor winding (the first motor winding (115) or the second motor winding (125)) is connected to the neutral points of the two radial support windings (the first radial support winding (113) and the second radial support winding (123)) via the first electromagnet coil (106) of the first thrust magnetic bearing (105) or the second electromagnet coil (108) of the second thrust magnetic bearing (107). However, instead of this, In this way, the same effect as in this modified example can be obtained even if the neutral point of one radial support winding (the first radial support winding (113) or the second radial support winding (123)) is connected to the neutral points of two motor windings (the first motor winding (115) and the second motor winding (125)) via the first electromagnet coil (106) of the first thrust magnetic bearing (105) or the second electromagnet coil (108) of the second thrust magnetic bearing (107).

[0065] (Second Modification of the First Embodiment) This modification differs from the first embodiment in that the neutral point of the first motor winding (115) and the neutral point of the second motor winding (125) are connected via the first electromagnet coil (106) of the first thrust magnetic bearing (105) as shown in Fig. 6, and the neutral point of the first radial support winding (113) and the neutral point of the second radial support winding (123) are connected via the second electromagnet coil (108) of the second thrust magnetic bearing (107) as shown in Fig. 7. In Figs. 6 and 7, the same elements as those in the first embodiment shown in Figs. 2 and 3 are denoted by the same reference numerals.

[0066] In this modification, a predetermined support current i is supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105). zf When trying to pass the current i through each phase of the second motor winding (125), in addition to the original motor drive current, zf / 3, the first electromagnet coil (106) will have a supporting current i zf can be passed as a zero-phase current. zfAfter flowing through the first electromagnet coil (106), it flows into the first motor winding (115). Therefore, the motor drive current (i um2 , i vm2 , i wm2 ) amplitude of I m2 , the phase is β2, and the motor drive current (i um1 , i vm1 , i wm1 ) amplitude of I m1 , with phase β1, i um2 =I m2 sin(β2)+i zf / 3 i vm2 =I m2 sin(β2+2π / 3)+i zf / 3 i wm2 =I m2 sin(β2+4π / 3)+i zf / 3 i um1 =I m1 sin(β1)-i zf / 3 i vm1 =I m1 sin(β1+2π / 3)-i zf / 3 i wm1 =I m1 sin(β1+4π / 3)-i zf / 3 If the inverters (116, 126) are controlled so as to satisfy the above condition, a predetermined support current i can be supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) without adding any switching element. zf can be flushed.

[0067] In addition, a predetermined supporting current i is supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (107). zr When trying to pass the current, in addition to the original radial support current, i zr / 3, the second electromagnet coil (108) will have a supporting current i zr can be passed as a zero-phase current.zr After flowing through the second electromagnet coil (108), it flows into the first radial support winding (113). Therefore, the radial support current (i ur2 , i vr2 , i wr2 ) amplitude of I r2 , the phase is φ2, and the radial support current (i ur1 , i vr1 , i wr1 ) amplitude of I r1 , with phase φ1, i ur2 =I r2 sin(φ2) + i zr / 3 i vr2 =I r2 sin(φ2+2π / 3)+i zr / 3 i wr2 =I r2 sin(φ2+4π / 3)+i zr / 3 i ur1 =I r1 sin(φ1)-i zr / 3 i vr1 =I r1 sin(φ1+2π / 3)-i zr / 3 i wr1 =I r1 ·sin(φ1+4π / 3)-i zr / 3 If the inverters (114, 124) are controlled so as to satisfy the above condition, a predetermined supporting current i can be supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (107) without adding any switching element. zr can be flushed.

[0068] As described above, in this modified example, by using two bearingless motors (110, 120) and operating the electromagnet coils (106, 108) of the two magnetic bearings (105, 107), respectively, without adding switching elements, it is possible to obtain the same effects as in the first embodiment.

[0069] In the example shown in FIG. 6 and FIG. 7, a support current i zf At the same time, a support current i flows from the second radial support winding (123) to the first radial support winding (113). zr However, the inverters (114, 116, 124, 126) control the voltages of the motor windings (115, 125) and the radial support windings (113, 123) to reduce the support current i zf , i zr The direction of flow and supporting current i zf , i zr The size of the can be adjusted.

[0070] Second embodiment <Magnetic bearing system configuration> The magnetic bearing system (100) of this embodiment differs from the first embodiment in that, as shown in Fig. 8, a first impeller (102) and a second impeller (103) are provided at the front end of the rotating shaft (101), thrust magnetic bearings (105, 107) are provided at the rear end of the rotating shaft (101), and a radial magnetic bearing (130) is provided instead of the second bearingless motor (120). That is, the magnetic bearing system (100) of this embodiment is not of a back-to-back type as in the first embodiment. In Fig. 8, the same elements as those in the first embodiment shown in Fig. 1 are denoted by the same reference numerals.

[0071] In the example shown in FIG. 8, the first bearingless motor (110) and the radial magnetic bearing (130) are arranged side by side in the axial direction of the rotating shaft (101), with the first bearingless motor (110) located on the rear side of the rotating shaft (101) and the radial magnetic bearing (130) located on the front side of the rotating shaft (101).

[0072] The radial magnetic bearing (130) is configured to support the radial load of the drive shaft (101) in a non-contact manner. The radial magnetic bearing (130) is fixed to the inner peripheral wall of the pressure vessel (150). The diameter of a portion (131) of the rotating shaft (101) facing the radial magnetic bearing (130) may be larger than the diameter of the remaining portion. The radial magnetic bearing (130) has a stator (132) having a plurality of teeth (not shown) and an electromagnet coil (135) wound around each of the teeth.

[0073] <Circuit for magnetic bearing system> The circuit of the magnetic bearing system (100) of this embodiment differs from that of the first embodiment in that, as shown in Fig. 9, a first electromagnet coil (106) of a first thrust magnetic bearing (105) and a second electromagnet coil (108) of a second thrust magnetic bearing (107) are connected in parallel between the neutral point of a first motor winding (115) of a first bearingless motor (110) and the neutral point of a first radial support winding (113) of the first bearingless motor (110). In Fig. 9, the same elements as those of the first embodiment shown in Figs. 2 and 3 are denoted by the same reference numerals.

[0074] In this embodiment, a predetermined supporting current i is supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105). zf When trying to pass the radial support current, in addition to the original radial support current, i zf / 3, the first electromagnet coil (106) will have a supporting current i zf can be passed as a zero-phase current. zf After flowing through the first electromagnet coil (106), the radial support current (i ur , i vr , i wr ) amplitude of I r , the phase is φ, and the motor drive current (i um , i vm , i wm ) amplitude of I m , with phase β, i ur =Ir sin(φ)+i zf / 3 i vr =I r sin(φ+2π / 3)+i zf / 3 i wr =I r sin(φ+4π / 3)+i zf / 3 i um =I m sin(β)-i zf / 3 i vm =I m sin(β+2π / 3)-i zf / 3 i wm =I m sin(β+4π / 3)-i zf / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined support current i can be supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) without adding any switching element. zf can be flushed.

[0075] On the other hand, a predetermined supporting current i is supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (107). zr When trying to pass a current of i in each phase of the first motor winding (115), in addition to the original motor drive current, zr / 3, the second electromagnet coil (108) will have a supporting current i zr can be passed as a zero-phase current. zr After flowing through the second electromagnet coil (108), it flows into the first radial support winding (113). Therefore, the motor drive current (i um , i vm , i wm ) amplitude of I m , phase is β, radial support current (i ur , i vr , i wr ) amplitude of I r , with phase φ, i um =I m sin(β)+izr / 3 i vm =I m sin(β+2π / 3)+i zr / 3 i wm =I m sin(β+4π / 3)+i zr / 3 i ur =I r sin(φ)-i zr / 3 i vr =I r sin(φ+2π / 3)-i zr / 3 i wr =I r sin(φ+4π / 3)-i zr / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined support current i can be supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (106) without adding any switching element. zr can be flushed.

[0076] In the example shown in FIG. 9, the inverters (114, 116) control the voltages of the radial support winding (113) and the motor winding (115), thereby making it possible to adjust the direction and magnitude of the current flowing between the neutral point of the first motor winding (115) and the neutral point of the first radial support winding (113).

[0077] As described above, according to this embodiment, the same effects as those of the first embodiment can be obtained even in a magnetic bearing system (100) other than the back-to-back type using two bearingless motors.

[0078] (First modified example of the second embodiment) 10 and 11, the magnetic bearing system (100) of this modification differs from the second embodiment in that a magnet (109) is provided in the second thrust magnetic bearing (107) instead of the second electromagnet coil (108), and only the first electromagnet coil (106) of the first thrust magnetic bearing (105) is connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113) of the first bearingless motor (110). In other words, the axial electromagnetic force generated on the rear side by the second thrust magnetic bearing (107) is constant, and the position of the disk portion (104), i.e., the position of the drive shaft (101), is controlled by controlling the current flowing through the first electromagnet coil (106) of the first thrust magnetic bearing (105). 10 and 11, the same elements as those in the second embodiment shown in FIGS. 8 and 9 are denoted by the same reference numerals.

[0079] In this modification, a predetermined support current i is supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105). zf When trying to pass the radial support current, in addition to the original radial support current, i zf / 3, the first electromagnet coil (106) will have a supporting current i zf can be passed as a zero-phase current. zf After flowing through the first electromagnet coil (106), the radial support current (i ur , i vr , i wr ) amplitude of I r , the phase is φ, and the motor drive current (i um , i vm , i wm ) amplitude of I m , with phase β, i ur =I r sin(φ)+i zf / 3 i vr =I r sin(φ+2π / 3)+i zf / 3 i wr =Ir sin(φ+4π / 3)+i zf / 3 i um =I m sin(β)-i zf / 3 i vm =I m sin(β+2π / 3)-i zf / 3 i wm =I m sin(β+4π / 3)-i zf / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined support current i can be supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) without adding any switching element. zf can be flushed.

[0080] According to this modification described above, it is possible to obtain the same effects as in the first embodiment in a magnetic bearing system (100) other than the back-to-back type, without providing a diode as in the second embodiment shown in FIG.

[0081] In the example shown in FIG. 11, a support current i flows from the radial support winding (113) to the motor winding (115). zf However, the inverters (114, 116) control the voltages of the radial support winding (113) and the motor winding (115) to reduce the support current i zf The direction of flow and supporting current i zf The size of the can be adjusted.

[0082] In addition, in this modification, the second thrust magnetic bearing (107) is provided with a magnet (109), but instead of this, a magnet may be provided in the first thrust magnetic bearing (105), and the second electromagnet coil (108) of the second thrust magnetic bearing (107) may be connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113) of the first bearingless motor (110). In other words, the axial electromagnetic force generated on the front side by the first thrust magnetic bearing (105) may be kept constant, and the position of the disk portion (104), i.e., the position of the drive shaft (101), may be controlled by controlling the current flowing through the second electromagnet coil (108) of the second thrust magnetic bearing (107).

[0083] (Second modified example of the second embodiment) The magnetic bearing system (100) of this modification is different from the second embodiment in that, as shown in Fig. 12, power is supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) from a dedicated power module (161), while, as shown in Fig. 13, the second electromagnet coil (108) of the second thrust magnetic bearing (107) is connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113) of the first bearingless motor (110). Here, a bias current is supplied to the second electromagnet coil (108). That is, the axial electromagnetic force generated by the second thrust magnetic bearing (107) on the rear side is constant, and the position of the disk part (104), i.e., the position of the drive shaft (101), is controlled by controlling the current flowing through the first electromagnet coil (106) of the first thrust magnetic bearing (105) using the inverter (161). 12 and 13, the same elements as those in the second embodiment shown in FIGS. 8 and 9 are denoted by the same reference numerals.

[0084] In this modification, a predetermined bias current i is applied to the second electromagnet coil (108) of the second thrust magnetic bearing (107). zr When trying to pass a current of i in each phase of the first motor winding (115), in addition to the original motor drive current, zr / 3, the bias current i zr can be passed as a zero-phase current. zr After flowing through the second electromagnet coil (108), it flows into the first radial support winding (113). Therefore, the motor drive current (i um , i vm , i wm ) amplitude of I m , phase is β, radial support current (i ur , i vr , i wr ) amplitude of I r , with phase φ, i um =I m sin(β)+i zr / 3 i vm =I m sin(β+2π / 3)+i zr / 3 i wm =I m sin(β+4π / 3)+i zr / 3 i ur =I r sin(φ)-i zr / 3 i vr =I r sin(φ+2π / 3)-i zr / 3 i wr =I r sin(φ+4π / 3)-i zr / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined bias current i can be supplied to the second electromagnet coil (108) of the second thrust magnetic bearing (106) without adding any switching element. zr can be flushed.

[0085] According to this modification described above, it is possible to reduce the cost of the inverter in a magnetic bearing system (100) other than the back-to-back type, without providing a diode as in the second embodiment shown in Fig. 9, or without providing a magnet as in the first modification of the second embodiment shown in Fig. 10. Specifically, it is possible to reduce the number of switching elements by two, as shown in Fig. 12, compared to a conventional inverter for a thrust magnetic bearing.

[0086] According to this modification, the axial electromagnetic force generated on the rotating shaft (101) by energizing the first electromagnet coil (106) of the first thrust magnetic bearing (105) and the axial electromagnetic force generated on the rotating shaft (101) by energizing the second electromagnet coil (108) of the second thrust magnetic bearing (107) are in the opposite directions to each other, and the control band of the second electromagnet coil (108) to which a bias current is supplied is configured to be lower than the control band of the first electromagnet coil (106). Here, since the second electromagnet coil (108) is connected between the first motor winding (115) and the first radial support winding (113) of the first bearingless motor (110), the inductance is increased and the control band of the second electromagnet coil (108) is lowered. Therefore, the switching frequency of the second electromagnet coil (108) can be lowered, and loss due to switching can be suppressed.

[0087] In the example shown in FIG. 13, the inverters (114, 116) control the voltages of the radial support winding (113) and the motor winding (115) to generate a bias current i zr This allows not only constant voltage control of the second electromagnet coil (108) but also low-bandwidth voltage control of the second electromagnet coil (108) in accordance with the load of the impellers (102, 103), etc.

[0088] In this modification, power is supplied from an inverter (161) to the first electromagnet coil (106) of the first thrust magnetic bearing (105), and the second electromagnet coil (108) to which a bias current is supplied is connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113) of the first bearingless motor (110). However, instead of this, power may be supplied from a dedicated inverter to the second electromagnet coil (108) to which a bias current is supplied, and the first electromagnet coil (106) for thrust control may be connected between the neutral point of the first motor winding (115) and the neutral point of the first radial support winding (113). Even in this case, the bias current inverter has a simpler configuration than the conventional inverter for thrust magnetic bearings, and costs can be reduced.

[0089] (Third modified example of the second embodiment) The magnetic bearing system (100) of this modification is different from the second modification of the second embodiment in that, as shown in Fig. 14, the second thrust magnetic bearing (107) is provided with a second electromagnet coil (108A) for thrust control and a third electromagnet coil (108B) for bias. As shown in Fig. 15, the first electromagnet coil (106) of the first thrust magnetic bearing (105) and the second electromagnet coil (108A) of the second thrust magnetic bearing (107) are supplied with power from a dedicated inverter (162). On the other hand, as shown in Fig. 16, the third electromagnet coil (108B) of the second thrust magnetic bearing (107) is connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113) of the first bearingless motor (110). 14 to 16, elements similar to those in the second embodiment shown in FIGS. 8 and 9 or the second modified example of the second embodiment shown in FIGS. 12 and 13 are denoted by the same reference numerals.

[0090] In this modification, a constant axial electromagnetic force is generated on the rear side by the third electromagnet coil (108B), while the position of the disk portion (104), i.e., the position of the drive shaft (101), is controlled by controlling the currents flowing through the first electromagnet coil (106) and the second electromagnet coil (108A) using an inverter (162). The control of the current flowing through the second electromagnet coil (108A) is for fine adjustment of the axial electromagnetic force generated by the third electromagnet coil (108B).

[0091] In this modification, a predetermined bias current i is applied to the third electromagnet coil (108B) of the second thrust magnetic bearing (107). zr When trying to pass a current of i in each phase of the first motor winding (115), in addition to the original motor drive current, zr / 3, the bias current i zr can be passed as a zero-phase current. zr After flowing through the second electromagnet coil (108), it flows into the first radial support winding (113). Therefore, the motor drive current (i um , i vm , i wm ) amplitude of I m , phase is β, radial support current (i ur , i vr , i wr ) amplitude of I r , with phase φ, i um =I m sin(β)+i zr / 3 i vm =I m sin(β+2π / 3)+i zr / 3 i wm =I m sin(β+4π / 3)+i zr / 3 i ur =I r sin(φ)-i zr / 3 i vr =I r sin(φ+2π / 3)-i zr / 3 i wr =I r sin(φ+4π / 3)-i zr / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined bias current i can be supplied to the third electromagnet coil (108B) of the second thrust magnetic bearing (106) without adding any switching element. zr can be flushed.

[0092] According to this modification described above, it is possible to reduce the cost of the inverter in a magnetic bearing system (100) other than the back-to-back type, without providing a diode as in the second embodiment shown in Fig. 9, or without providing a magnet as in the first modification of the second embodiment shown in Fig. 10. Specifically, by providing the third electromagnet coil (108B) for bias in the second thrust magnetic bearing (106), it is possible to reduce the magnitude of the current flowing in the second electromagnet coil (108A) for thrust control. Therefore, the current capacity of the inverter (162) can be reduced compared to inverters for conventional thrust magnetic bearings, and this makes it possible to reduce costs.

[0093] According to this modification, the axial electromagnetic force generated on the rotating shaft (101) by energizing the second electromagnet coil (108A) of the second thrust magnetic bearing (107) and the axial electromagnetic force generated on the rotating shaft (101) by energizing the third electromagnet coil (108B) of the same second thrust magnetic bearing (107) are in the same direction, and the control band of the third electromagnet coil (108B) to which a bias current is supplied is configured to be lower than the control band of the second electromagnet coil (108A). Here, since the third electromagnet coil (108B) is connected between the first motor winding (115) and the first radial support winding (113) of the first bearingless motor (110), the inductance is increased and the control band of the third electromagnet coil (108B) is lowered. Therefore, the switching frequency of the third electromagnet coil (108B) can be lowered, and loss due to switching can be suppressed.

[0094] In this modification, the direction of the current flowing through the second electromagnet coil (108A) for thrust control may be adjustable by controlling an inverter (162) shown in FIG.

[0095] In the example shown in FIG. 16, the inverters (114, 116) control the voltages of the radial support winding (113) and the motor winding (115) to generate a bias current i zr This allows not only constant voltage control of the third electromagnet coil (108B) but also low-bandwidth voltage control of the third electromagnet coil (108B) in response to the load of the impellers (102, 103), etc.

[0096] Third embodiment The magnetic bearing system (100) of this embodiment differs from the second embodiment (see FIGS. 8 and 9) in that the electromagnet coil (135) of the radial magnetic bearing (130) is connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113) of the first bearingless motor (110) instead of the electromagnet coils (106, 108) of the thrust magnetic bearings (105, 107). This makes it possible to obtain the same effects as the second embodiment.

[0097] 17 and 18, in the present embodiment, a bias electromagnet coil (136) may be provided in the radial magnetic bearing (130) in addition to the radial control electromagnet coil (135), and the electromagnet coil (136) may be connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113). In this case, the radial control electromagnet coil (135) is supplied with power from a dedicated inverter.

[0098] Specifically, the radial magnetic bearing (130) includes a stator (132) having a back yoke portion (133) and a plurality of teeth portions (134), and an electromagnet coil (135) wound around the teeth portions (134). The electromagnet coils (135) are arranged in pairs, for example, in a first radial direction and in a second radial direction perpendicular to the first radial direction, with the rotation shaft (101) (expanded diameter portion (102)) between them. Here, one of the pair of electromagnet coils (135) is replaced with a bias electromagnet coil (136), and the bias electromagnet coil (136) is connected between the neutral point of the first motor winding (115) and the neutral point of the first radial support winding (113). The radial electromagnetic force generated by the bias electromagnet coil (136) is constant, and the position of the enlarged diameter portion (102), i.e., the position of the drive shaft (101), is controlled by controlling the current flowing through the radial control electromagnet coil (135). In Fig. 18, elements similar to those in the second embodiment shown in Fig. 9 are denoted by the same reference numerals.

[0099] A predetermined bias current i is applied to the bias electromagnet coil (136). zf When trying to pass the radial support current, in addition to the original radial support current, i zf / 3, the bias current i zf can be passed as a zero-phase current. zf After flowing through the bias electromagnet coil (136), it flows into the first motor winding (115). Therefore, the radial support current (i ur , i vr , i wr ) amplitude of I r , the phase is φ, and the motor drive current (i um , i vm , i wm ) amplitude of I m , with phase β, i ur =I r sin(φ)+i zf / 3 i vr =I r sin(φ+2π / 3)+i zf / 3 i wr =I r sin(φ+4π / 3)+i zf / 3 i um =I m sin(β)-i zf / 3 i vm =I m sin(β+2π / 3)-i zf / 3 i wm =I m sin(β+4π / 3)-i zf / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined bias current i can be supplied to the bias electromagnet coil (136) without adding a switching element. zf can be flushed.

[0100] According to the configurations described above and shown in FIGS. 17 and 18, it is possible to obtain the same effects as those of the second modified example of the second embodiment.

[0101] (Modification of the third embodiment) The magnetic bearing system (100) of this modification differs from the third embodiment in that, as shown in Fig. 19, one of a pair of electromagnet coils (135) arranged on either side of the rotating shaft (101) (expanded diameter portion (102)) is replaced with a bias electromagnet coil (136) and a radial control electromagnet coil (137). The bias electromagnet coil (136) is connected between the neutral point of the first motor winding (115) of the first bearingless motor (110) and the neutral point of the first radial support winding (113), as in the third embodiment shown in Fig. 18. In addition, the radial control electromagnet coils (135, 137) are supplied with power from a dedicated inverter.

[0102] According to this modification, it is possible to obtain the same effects as those of the third modification of the second embodiment.

[0103] (Fourth embodiment) In the magnetic bearing system (100) of the above-described first to third embodiments (including modified examples; the same applies below), when a zero-phase-sequence current is passed through the first bearingless motor (110) and / or the second bearingless motor (120), the shaft suspension force is affected thereby, and motor control may become difficult. Specifically, when attempting to control the shaft suspension force along two axes (x-axis and y-axis), passing a zero-phase-sequence current may cause pulsation in the shaft suspension force Fx in the x-axis direction and the shaft suspension force Fy in the y-axis direction, which may cause interference between the shaft suspension force Fx and the shaft suspension force Fy.

[0104] Therefore, in this embodiment, the radial support windings (113, 123) of the bearingless motors (110, 120) are wound using short-pitch winding, and the winding pitch of the radial support windings (113, 123) is set to at least half the number of slots of each pole of the radial support windings (113, 123). As a result, even if a zero-phase current is passed through the radial support windings (113, 123), the effect of the zero-phase current on the axial support force of the radial support windings (113, 123) can be suppressed, making it easier to control the bearingless motors (110, 120).

[0105] In addition, the number of slots for each pole of the radial support winding (113, 123) of the bearingless motor (110, 120) is "total number of slots / number of poles of the support winding," and the number of slots for each pole and each phase of the radial support winding (113, 123) of the bearingless motor (110, 120) is "number of slots for each pole / number of phases of the radial support winding (113, 123)."

[0106] A specific example will be described below in which the first bearingless motor (110) is a CPM motor (consequent pole motor). Fig. 20 is a schematic diagram showing a cross section perpendicular to the axial direction of a CPM motor with 8 motor winding poles, 2 support winding poles, and 24 slots. In Fig. 20, the same components as those in the magnetic bearing system (100) shown in Fig. 1 are denoted by the same reference numerals.

[0107] As shown in FIG. 20, the first bearingless motor (110) has a first rotor (111) and a first stator (112). The first rotor (111) is fixed to the drive shaft (101). A plurality of permanent magnets (111a) are embedded in a core portion of the first rotor (111). The first stator (112) has a plurality of teeth (112a) (24 in this example), and a first radial support winding (113) and a first motor winding (115) are arranged in slots (112b), which are spaces between the teeth (112a). In this example, the first radial support winding (113) and the first motor winding (115) are three-phase windings, i.e., U-phase, V-phase, and W-phase.

[0108] Fig. 21 shows the arrangement of U-phase, V-phase, and W-phase motor windings when the first motor winding (115) of the first bearingless motor (110) shown in Fig. 20 is configured as an 8-pole full-pitch distributed winding (2 layers). Each motor winding is, for example, 8 turns of four bundled conductors with a wire diameter of 0.75 mm (4 parallel). In Fig. 21, the motor windings of each phase are represented by circles (x within a circle indicates that the current flows from the front to the back of the page, and · indicates that the current flows from the back to the front of the page), and corresponding windings are given the same number.

[0109] Fig. 22 shows the arrangement of support windings for the U, V, and W phases when the first radial support winding (113) of the first bearingless motor (110) shown in Fig. 20 is configured as a 2-pole full-pitch (12-pitch) distributed winding. In Fig. 22, the support windings of each phase are indicated by a circle (an x within a circle indicates that the current flows from the front of the page to the back of the page, and a circle indicates that the current flows from the back of the page to the front of the page), and corresponding windings are given the same number. As shown in Fig. 22, in each support winding arrangement, 12 teeth (112a) are interposed between corresponding windings, and the winding pitch is set to 12.

[0110] The influence of the zero-sequence current on the shaft support force in a full-pitch distributed winding support winding arrangement in which the shaft support force per unit support current is the largest will be described below.

[0111] Figure 23 shows the supporting force interference angle between the magnetic supporting force in the x-axis direction and the magnetic supporting force in the y-axis direction in the first bearingless motor (110) shown in Figures 20 to 22. In reality, when a magnetic supporting force in the x-axis direction is generated, it is preferable that a magnetic supporting force in the y-axis direction is not generated, but the degree of mutual interference when both supporting forces are generated is represented by the supporting force interference angle shown in Figure 23.

[0112] FIG. 24 shows the influence of the zero-phase current iz (unit: A) on the relationship between the supporting force Fx in the x-axis direction, the supporting force Fy in the y-axis direction, and the supporting force interference angle and the electrical angle in the first bearingless motor (110) shown in FIG. 20. As shown in FIG. 24, even if the zero-phase current iz flows, the average value of the supporting force Fx does not change, but as the zero-phase current iz increases, the pulsation of the supporting force Fy increases and the supporting force interference angle increases. Note that the numerical values ​​shown in FIG. 24 are, as an example, values ​​when the CPM motor shown in FIG. 20 is configured using a stator core with an outer diameter of 130 mm, an inner diameter of 65 mm, and a lamination thickness of 25 mm, and a rotor core with an outer diameter of 63 mm and a lamination thickness of 25 mm. 35H360 was used as the material for the stator core and the rotor core, and N48 with a thickness of 3 mm was used as the magnet embedded in the rotor core.

[0113] Therefore, in this embodiment, in order to suppress the effect of the zero-sequence current on the axial support force of the first radial support winding (113), the first radial support winding (113) is wound using short-pitch winding, and the winding pitch of the first radial support winding (113) is set to at least half the number of slots of each pole of the radial support winding (113). Below, the configuration of the first bearingless motor (110) of this embodiment will be specifically described based on a theoretical calculation formula for the support forces Fx, Fy when a zero-sequence current is applied.

[0114] The calculation formulas for the bearing capacities Fx and Fy are expressed by the following formulas (1) and (2).

[0115]

number

[0116]

number

[0117] In equations (1) and (2), R is the radius from the center of the rotating shaft (101) to the center of the air gap (the space between the rotor core and the stator core), L is the stack thickness of the motor, φ is the phase (fixed coordinate), μ0 is the magnetic permeability of a vacuum, and Br is the radial magnetic flux density of the air gap.

[0118] The magnetic flux density Br is expressed as the product of permeance P and magnetomotive force F (magnet magnetomotive force Fpm, support winding magnetomotive force Fs, and motor winding magnetomotive force Fm) by the following equation (3).

[0119]

number

[0120] Permeance P is expressed by the following equation (4).

[0121]

number

[0122] In equation (4), g is the radial length of the air gap, P0 is a permeance component that does not change depending on space and phase, P4 is a permeance component that changes depending on space and phase, ω is an electrical angular frequency, and t is time.

[0123] The magnetomotive force Fpm of the magnet is expressed by the following equation (5) with four pole pairs as the fundamental wave.

[0124]

number

[0125] In equation (5), Fpm4 is the amplitude of the magnetomotive force Fpm.

[0126] The magnetomotive force Fs of the support winding is expressed as the product of the support winding distribution Ns(φ) (U-phase distribution Nsu(φ), V-phase distribution Nsv(φ), W-phase distribution Nsw(φ)) and the support current is (U-phase current isu, V-phase current isv, W-phase current isw), as shown in Equation (6) below.

[0127]

number

[0128] The supporting winding distribution Ns(φ) is expressed by the following equations (7) to (9) taking into account one pole pair as the fundamental wave and third and fifth spatial harmonics.

[0129]

number

[0130]

number

[0131]

number

[0132] In equations (7) to (9), Ns is the number of turns of the support winding, and Ns1, Ns3, and Ns5 are the primary, tertiary, and quintic support winding coefficients, respectively.

[0133] In addition, the support current is (U-phase current isu, V-phase current isv, W-phase current isw) is obtained by superimposing the zero-phase current iz on the DC radial support current Is. isu=-Is+iz / 3 isv=Is / 2+iz / 3 isw=Is / 2+iz / 3 This is expressed as:

[0134] The magnetomotive force Fm of the motor windings is expressed as the product of the motor winding distribution Nm(φ) (U-phase distribution Nmu(φ), V-phase distribution Nmv(φ), W-phase distribution Nmw(φ)) and the motor current im (U-phase current imu, V-phase current imv, W-phase current imw), as shown in Equation (10) below.

[0135]

number

[0136] The motor winding distribution Nm(φ) is expressed by the following equations (11) to (13) taking into account four pole pairs as the fundamental wave and three times spatial harmonics.

[0137]

number

[0138]

number

[0139]

number

[0140] In equations (11) to (13), Nm is the number of turns of the motor winding, Nm4, Nm 12 are the primary and tertiary motor winding coefficients, respectively.

[0141] In addition, the motor current im (U-phase current imu, V-phase current imv, W-phase current imw) is calculated by superimposing the zero-phase current iz on the motor current Im. imu = -Im sin(ωt)-iz / 3 imv=-Im·sin(ωt-2π / 3)-iz / 3 imw=-Im·sin(ωt-4π / 3)-iz / 3 This is expressed as:

[0142] By substituting the above equations into equations (1) and (2), the bearing capacities Fx and Fy are expressed as the following equations (14) and (15), respectively.

[0143]

number

[0144]

number

[0145] In equation (14), the first term is the DC supporting force due to the support current, the second term includes interference due to the zero-sequence current (Ns3iz) flowing through the support winding, the third term includes interference due to the zero-sequence current (Ns3iz) flowing through the support winding and the fundamental current (Nm4Im) flowing through the motor winding, and the fourth term includes interference due to the zero-sequence current (Ns3iz) flowing through the support winding and the zero-sequence current (Nm 12 In the second and third terms of equation (14), the effect of the zero-phase current can be eliminated (de-interference) by setting the tertiary winding factor Ns3 of the support winding to 0. In the fourth term of equation (14), even if the tertiary winding factor Ns3 of the support winding is set to 0, the tertiary winding factor Nm 12 However, since the square of the permeance component (rotor permeance) P4 is small, the effect of the interference is small, and the tertiary winding coefficient Nm 12 It is also possible to make it non-interacting by setting it to 0.

[0146] In equation (15), the first term includes the interference due to the zero-sequence current (Ns3iz) flowing through the support winding, the second term includes the interference due to the zero-sequence current (Ns3iz) flowing through the support winding and the fundamental current (Nm4Im) flowing through the motor winding, and the third term includes the interference due to the zero-sequence current (Ns3iz) flowing through the support winding and the zero-sequence current (Nm 12In the first and second terms of equation (15), the effect of the zero-phase current can be eliminated (de-interference) by setting the tertiary winding factor Ns3 of the support winding to 0. In the third term of equation (15), even if the tertiary winding factor Ns3 of the support winding is set to 0, the tertiary winding factor Nm 12 acts on iz, causing sin2ωt pulsation (interference), but since the square of the permeance component (rotor permeance) P4 is small, the effect of the interference is small, and the tertiary winding coefficient Nm 12 It is also possible to make it non-interacting by setting it to 0.

[0147] FIG. 25 shows the change in absolute value of the support winding coefficients Ns1, Ns3, and Ns5 of the first, third, and fifth orders when the winding pitch of the first radial support winding (113) in the first bearingless motor (110) shown in FIG. 20 is changed. (2n-1) is calculated by the following formula (16).

[0148]

number

[0149] In equation (16), Nsh is the short pitch winding factor, Ndis is the distributed winding factor, and p n is the number of pole pairs, q is the number of slots for each pole and phase (in this example, q=4), α is the angle per slot (α=2π / number of slots, and in this example, α=π / 12), Np is the winding pitch (number of pitches), and θcp is the coil pitch angle (θcp=α×Np, and in this example, θcp=π / 12×Np).

[0150] As shown in FIG. 25, when the first bearingless motor (110) is the CPM motor shown in FIG. 20, the winding pitch of the first radial support winding (113) is set to be half or more of the number of slots of each pole of the radial support winding (113) (i.e., six or more), for example, eight, whereby the tertiary winding coefficient Ns3 becomes zero, and the influence of the zero-sequence current can be eliminated (de-interfered) in the second and third terms of equation (14) expressing the supporting force Fx and the first and second terms of equation (15) expressing the supporting force Fy.

[0151] FIG. 26 shows the arrangement of support windings for the U, V, and W phases in the case where the first radial support winding (113) of the CPM motor shown in FIG. 20 is configured as a 2-pole, short-pitch, 8-pitch distributed winding (2 layers) as the first bearingless motor (110) of this embodiment. In FIG. 26, the support windings of each phase are indicated by a circle (a cross in a circle indicates that the current direction is from the front to the back of the page, and a circle indicates that the current direction is from the back to the front of the page), and corresponding windings are assigned the same number. As shown in FIG. 26, in each support winding arrangement, eight teeth (112a) are interposed between corresponding windings, and the winding pitch is set to 8. Each support winding is, for example, wound with 8 turns of a conductor having a wire diameter of 0.8 mm.

[0152] FIG. 27 shows the influence of the zero-phase current iz (unit: A) on the relationship between the supporting force Fx in the x-axis direction and the supporting force interference angle and the electrical angle in the first bearingless motor (110) of this embodiment configured as shown in FIG. 26. As shown in FIG. 27, even if the zero-phase current iz flows, no change is observed in the supporting force Fx and the supporting force interference angle. Therefore, by setting the winding pitch of the first radial support winding (113) to 8, the influence of the zero-phase current on the axial supporting force of the first radial support winding (113) can be eliminated (de-interference is eliminated). Note that the numerical values ​​shown in FIG. 27 are values ​​when the CPM motor shown in FIG. 20 is configured, as an example, using a stator core with an outer diameter of 130 mm, an inner diameter of 65 mm, and a lamination thickness of 25 mm, and a rotor core with an outer diameter of 63 mm and a lamination thickness of 25 mm. 35H360 is used as the material for the stator core and the rotor core, and N48 with a thickness of 3 mm is used as the magnet embedded in the rotor core.

[0153] In the above description, the winding pitch of the first radial support winding (113) is set so that the tertiary winding factor Ns3 is 0. However, the present invention is not limited to this. Based on the relationship between the support winding factor of each order and the winding pitch shown in FIG. 25, the winding pitch of the first radial support winding (113) may be set to approximately 2 / 3 of the number of slots of each pole of the radial support winding (113) (approximately 8 in this example) to minimize the tertiary support winding factor Ns3. Alternatively, the winding pitch of the first radial support winding (113) may be set to approximately 2 / 3 or more of the number of slots of each pole of the radial support winding (113) (8 or more in this example) to reduce the tertiary support winding factor Ns3 while suppressing a decrease in the primary support winding factor Ns1. This makes it possible to reduce interference of the zero-phase current while ensuring a necessary axial support force.

[0154] (Modification of the fourth embodiment) This modification differs from the fourth embodiment in that an SPM (Surface Permanent Magnet) motor is used as the first bearingless motor (110). In an SPM motor, the rotor core is cylindrical, so the permeance is only a DC value (average value) and has no fluctuation component. In addition, the SPM motor is a four-pole motor, and the support current is AC.

[0155] Fig. 28 is a schematic diagram showing a cross section perpendicular to the axial direction of an SPM motor with four motor winding poles, two support winding poles, and 24 slots. In Fig. 28, the same components as those in the CPM motor shown in Fig. 20 are given the same reference numerals.

[0156] As shown in FIG. 28, the first bearingless motor (110) has a first rotor (111) and a first stator (112). The first rotor (111) is fixed to the drive shaft (101). A permanent magnet (111a) is arranged in an annular shape on the outer periphery of a core portion of the first rotor (111). The first stator (112) has a plurality of teeth (112a) (24 in this example), and a first radial support winding (113) and a first motor winding (115) are arranged in slots (112b), which are spaces between the teeth (112a). In this example, the first radial support winding (113) and the first motor winding (115) are three-phase windings of U-phase, V-phase, and W-phase, respectively.

[0157] Fig. 29 shows the arrangement of U-phase, V-phase, and W-phase motor windings when the first motor winding (115) of the first bearingless motor (110) shown in Fig. 28 is configured as a 4-pole full-pitch distributed winding (2 layers). Each motor winding is, for example, 8 turns of four bundled conductors with a wire diameter of 0.75 mm (4 parallel). In Fig. 29, the motor windings of each phase are represented by a circle (an x within a circle indicates that the current flows from the front to the back of the page, and a circle indicates that the current flows from the back to the front of the page), and corresponding windings are given the same number.

[0158] Fig. 30 shows the arrangement of support windings for the U, V, and W phases when the first radial support winding (113) of the first bearingless motor (110) shown in Fig. 28 is configured as a 2-pole full-pitch (12-pitch) distributed winding. In Fig. 30, the support windings of each phase are indicated by a circle (an x within a circle indicates that the current flows from the front of the page to the back of the page, and a circle indicates that the current flows from the back of the page to the front of the page), and corresponding windings are given the same number. As shown in Fig. 30, in each support winding arrangement, 12 teeth (112a) are interposed between corresponding windings, and the winding pitch is set to 12.

[0159] The influence of the zero-sequence current on the shaft support force in a full-pitch distributed winding support winding arrangement in which the shaft support force per unit support current is the largest will be described below.

[0160] FIG. 31 shows the influence of the zero-phase current iz (unit: A) on the relationship between the supporting force Fx in the x-axis direction, the supporting force Fy in the y-axis direction, and the supporting force interference angle and the electrical angle in the first bearingless motor (110) shown in FIGS. 28 to 30. As shown in FIG. 31, even if the zero-phase current iz flows, the average value of the supporting force Fx does not change, but as the zero-phase current iz increases, the pulsation of the supporting force Fy increases and the supporting force interference angle increases. Note that the numerical values ​​shown in FIG. 31 are, as an example, values ​​when the SPM motor shown in FIG. 28 is configured using a stator core with an outer diameter of 130 mm, an inner diameter of 65 mm, and a lamination thickness of 25 mm, and a rotor core with an outer diameter of 63 mm and a lamination thickness of 25 mm. 35H360 was used as the material for the stator core and the rotor core, and N48 with a thickness of 3 mm was used as the magnet embedded in the rotor core.

[0161] Therefore, in this modification, in order to suppress the effect of the zero-sequence current on the axial support force of the first radial support winding (113), the first radial support winding (113) is wound using short-pitch winding, and the winding pitch of the first radial support winding (113) is set to at least half the number of slots of each pole of the radial support winding (113). Below, the configuration of the first bearingless motor (110) of this modification will be specifically described based on theoretical calculation formulas for the support forces Fx, Fy when a zero-sequence current is applied.

[0162] The calculation formulas for the supporting forces Fx and Fy are expressed by the formulas (1) and (2) as in the fourth embodiment. The magnetic flux density Br in the formulas (1) and (2) is expressed by the formula (3) as the product of the permeance P and the magnetomotive force F (magnet magnetomotive force Fpm, magnetomotive force Fs of the supporting winding, and magnetomotive force Fm of the motor winding) as in the fourth embodiment.

[0163] Permeance P is expressed by the following equation (17).

[0164]

number

[0165] In equation (17), μ0 is the magnetic permeability of a vacuum, g is the radial length of the air gap, and P0 is a permeance component that does not change with space or phase.

[0166] The magnetomotive force Fpm of the magnet is expressed by the following equation (18) with two pole pairs as the fundamental wave.

[0167]

number

[0168] In equation (18), Fpm2 is the amplitude of the magnetomotive force Fpm.

[0169] The magnetomotive force Fs of the support winding is expressed as the product of the support winding distribution Ns(φ) (U-phase distribution Nsu(φ), V-phase distribution Nsv(φ), W-phase distribution Nsw(φ)) and the support current is (U-phase current isu, V-phase current isv, W-phase current isw), by equation (6), as in the fourth embodiment.

[0170] The supporting winding distribution Ns(φ) is expressed by the formulas (7) to (9) in the same manner as in the fourth embodiment, taking into account one pole pair as the fundamental wave and third and fifth spatial harmonics.

[0171] In addition, the support current is (U-phase current isu, V-phase current isv, W-phase current isw) is obtained by superimposing the zero-phase current iz on the AC radial support current Is. isu = Is cos(ωt) + iz / 3 isv=Is·cos(ωt-2π / 3)+iz / 3 isw=Is·cos(ωt-4π / 3)+iz / 3 This is expressed as:

[0172] The magnetomotive force Fm of the motor windings is expressed as the product of the motor winding distribution Nm(φ) (U-phase distribution Nmu(φ), V-phase distribution Nmv(φ), W-phase distribution Nmw(φ)) and the motor current im (U-phase current imu, V-phase current imv, W-phase current imw), as in the fourth embodiment, by equation (10).

[0173] The motor winding distribution Nm(φ) is expressed by the following equations (19) to (21) taking into account two pole pairs as the fundamental wave and three times the spatial harmonics.

[0174]

number

[0175]

number

[0176]

number

[0177] In equations (19) to (21), Nm is the number of turns of the motor winding, and Nm2 and Nm6 are the primary and tertiary motor winding coefficients, respectively.

[0178] In addition, the motor current im (U-phase current imu, V-phase current imv, W-phase current imw) is calculated by superimposing the zero-phase current iz on the motor current Im. imu = -Im sin(ωt)-iz / 3 imv=-Im·sin(ωt-2π / 3)-iz / 3 imw=-Im·sin(ωt-4π / 3)-iz / 3 This is expressed as:

[0179] By substituting the above equations into equations (1) and (2), the bearing capacities Fx and Fy are expressed as the following equations (22) and (23), respectively.

[0180]

number

[0181]

number

[0182] In equation (22), the first term is the DC supporting force due to the support current, the second term includes interference due to the zero-sequence current (Ns3iz) flowing in the support winding, the third term includes interference due to the zero-sequence current (Ns3iz) flowing in the support winding and the fundamental current (Nm2Im) flowing in the motor winding, and the fourth term includes interference due to the fundamental current (Ns5Is) flowing in the support winding and the zero-sequence current (Nm6iz) flowing in the motor winding. In the second and third terms of equation (22), the influence of the zero-sequence current can be eliminated (de-interference) by setting the tertiary winding coefficient Ns3 of the support winding to 0. In the fourth term of equation (22), even if the tertiary winding coefficient Ns3 of the support winding is set to 0, the tertiary winding coefficient Nm6 of the motor winding will interact with iz, causing cosωt pulsation (interference). However, since the product of the fifth winding coefficient Ns5 of the support winding and the tertiary winding coefficient Nm6 of the motor winding is small, the effect of interference is small, and it is also possible to eliminate interference by setting the tertiary winding coefficient Nm6 of the motor winding to 0.

[0183] In equation (23), the first term indicates the effect of armature reaction, the second term includes interference due to the zero-sequence current (Ns3iz) flowing through the support winding, the third term includes interference due to the zero-sequence current (Ns3iz) flowing through the support winding and the fundamental current (Nm2Im) flowing through the motor winding, and the fourth term includes interference due to the fundamental current (Ns5Is) flowing through the support winding and the zero-sequence current (Nm6iz) flowing through the motor winding. In the second and third terms of equation (23), the effect of the zero-sequence current can be eliminated (de-interference) by setting the tertiary winding coefficient Ns3 of the support winding to 0. In the fourth term of equation (23), even if the tertiary winding coefficient Ns3 of the support winding is set to 0, the tertiary winding coefficient Nm6 of the motor winding will interact with iz, causing sinωt pulsation (interference). However, since the product of the quintic winding coefficient Ns5 of the support winding and the tertiary winding coefficient Nm6 of the motor winding is small, the effect of interference is small, and it is also possible to eliminate interference by setting the tertiary winding coefficient Nm6 of the motor winding to 0.

[0184] In the first bearingless motor (110) shown in FIG. 28, the absolute values ​​of the support winding coefficients Ns1, Ns3, and Ns5 of the first, third, and fifth orders when the winding pitch of the first radial support winding (113) is changed are shown in FIG. 25, similarly to the fourth embodiment.(2n-1) is also calculated by the formula (16) in the same manner as in the fourth embodiment.

[0185] Therefore, when the first bearingless motor (110) is the SPM motor shown in FIG. 28, by setting the winding pitch of the first radial support winding (113) to be half or more of the number of slots of each pole of the radial support winding (113) (i.e., six or more), for example, eight, as shown in FIG. 25, the tertiary winding coefficient Ns3 becomes zero, and the influence of the zero-sequence current can be eliminated (de-interfered) in the second and third terms of equation (22) expressing the supporting force Fx and the second and third terms of equation (23) expressing the supporting force Fy.

[0186] FIG. 32 shows the arrangement of support windings for the U, V, and W phases in a case where the first radial support winding (113) of the SPM motor shown in FIG. 28 is configured as a 2-pole, short-pitch, 8-pitch distributed winding (2 layers) as a first bearingless motor (110) of this modified example. In FIG. 32, the support windings of each phase are indicated by a circle (an x in a circle indicates that the current direction is from the front to the back of the page, and a circle indicates that the current direction is from the back to the front of the page), and corresponding windings are assigned the same number. As shown in FIG. 32, in each support winding arrangement, eight teeth (112a) are interposed between corresponding windings, and the winding pitch is set to 8. Each support winding is, for example, wound with 8 turns of a conductor having a wire diameter of 0.8 mm.

[0187] FIG. 33 shows the influence of the zero-phase current iz (unit: A) on the relationship between the supporting force Fx in the x-axis direction, the supporting force Fy in the y-axis direction, and the supporting force interference angle and the electrical angle in the first bearingless motor (110) of this modified example configured as shown in FIG. 32. As shown in FIG. 33, even if the zero-phase current iz is applied, no change is observed in the supporting forces Fx, Fy, and the supporting force interference angle. Therefore, by setting the winding pitch of the first radial support winding (113) to 8, the influence of the zero-phase current on the axial supporting force of the first radial support winding (113) can be eliminated (de-interference is eliminated). Note that the numerical values ​​shown in FIG. 33 are, as an example, values ​​when the SPM motor shown in FIG. 28 is configured using a stator core with an outer diameter of 130 mm, an inner diameter of 65 mm, and a lamination thickness of 25 mm, and a rotor core with an outer diameter of 63 mm and a lamination thickness of 25 mm. The material used for the stator core and rotor core was 35H360, and the magnet embedded in the rotor core was N48 with a thickness of 3 mm.

[0188] In the above description, the winding pitch of the first radial support winding (113) is set so that the tertiary winding factor Ns3 is 0. However, the present invention is not limited to this. Based on the relationship between the support winding factor of each order and the winding pitch shown in FIG. 25, the winding pitch of the first radial support winding (113) may be set to approximately 2 / 3 of the number of slots of each pole of the radial support winding (113) (approximately 8 in this example) to minimize the tertiary support winding factor Ns3. Alternatively, the winding pitch of the first radial support winding (113) may be set to approximately 2 / 3 or more of the number of slots of each pole of the radial support winding (113) (8 or more in this example) to reduce the tertiary support winding factor Ns3 while suppressing a decrease in the primary support winding factor Ns1. This makes it possible to reduce interference of the zero-phase current while ensuring a necessary axial support force.

[0189] Fifth embodiment An air conditioner (1) shown in FIG. 34 will be described below as an example of a refrigeration system including a compressor (10) provided with a magnetic bearing system (100) according to the first to fourth embodiments (including modifications, the same applies below).

[0190] The air conditioner (1) is a device that conditions a target space by a vapor compression refrigeration cycle. The air conditioner (1) is capable of performing cooling operation and mainly includes a compressor (10), a heat source side heat exchanger (3), an expansion mechanism (4), and a utilization side heat exchanger (5).

[0191] The compressor (10) draws in low-pressure refrigerant flowing through the suction pipe (6) via the suction port (11), compresses the refrigerant drawn in via the suction port (11) to produce high-pressure refrigerant, and then discharges the refrigerant via the discharge port (12) to the discharge pipe (7). The suction pipe (6) is a refrigerant pipe that guides the refrigerant discharged from the utilization-side heat exchanger (5) to the suction side (suction port (11)) of the compressor (10), and the discharge pipe (7) is a refrigerant pipe that guides the refrigerant discharged from the compressor (10) via the discharge port (12) to the inlet of the heat source-side heat exchanger (3).

[0192] As described in the first embodiment, the compressor (10) mainly includes a drive shaft (101), impellers (102, 103), and bearingless motors (110, 120). The impellers (102, 103) receive a driving force from the drive shaft (101) of the bearingless motors (110, 120) and rotate about the drive shaft (101). As a result, the compressor (10) compresses the refrigerant sucked in through the suction port (11).

[0193] The heat source side heat exchanger (3) functions as a refrigerant radiator that radiates heat from the refrigerant discharged from the compressor (10) by exchanging heat with water or air serving as a cooling source. One end of the heat source side heat exchanger (3) is connected to a discharge port (12) of the compressor (10) via a discharge pipe (7). The other end of the heat source side heat exchanger (3) is connected to the expansion mechanism (4).

[0194] The expansion mechanism (4) is a mechanism for reducing the pressure of the refrigerant that has dissipated heat in the heat source-side heat exchanger (3) and is constituted, for example, by an electric expansion valve. One end of the expansion mechanism (4) is connected to the heat source-side heat exchanger (3). The other end of the expansion mechanism (4) is connected to the utilization-side heat exchanger (5).

[0195] The utilization side heat exchanger (5) functions as a refrigerant heater that heats the refrigerant decompressed in the expansion mechanism (4) by exchanging heat with water or air as a heat source. One end of the utilization side heat exchanger (5) is connected to the expansion mechanism (4). The other end of the utilization side heat exchanger (5) is connected to the suction port (11) of the compressor (10) via a suction pipe (6).

[0196] As described above, in the air conditioning system (1), the compressor (10), the heat source side heat exchanger (3), the expansion mechanism (4), and the utilization side heat exchanger (5) are sequentially connected by refrigerant piping including the suction pipe (6) and the discharge pipe (7), thereby forming a path (8) through which the refrigerant circulates.

[0197] The refrigeration system (air conditioner (1)) of this embodiment uses a compressor (10) driven by the magnetic bearing system (100) of the first to fourth embodiments, so that the cost of the inverter can be reduced and the refrigeration system can be manufactured at low cost.

[0198] (Other embodiments) In the above embodiment (including the modified examples; the same applies below), the magnetic bearing system (100) is applied to a compressor (10) as an example. However, the use of the magnetic bearing system (100) is not particularly limited, and the magnetic bearing system (100) may be applied to a rotating electric machine such as a motor or a generator, or various devices equipped with such a rotating electric machine.

[0199] In the above embodiment, the electromagnet coil (106, 108, 108B) of the thrust magnetic bearing (105, 107) or the electromagnet coil (135, 136) of the radial magnetic bearing (130) is connected between the neutral points of two polyphase windings of the motor winding (115, 125) and the radial support winding (113, 123) of the bearingless motor (110, 120). However, the present invention is not limited to this, and the electromagnet coil (106, 108, 108B, 135, 136) may be connected between the neutral point of one of the two polyphase windings and the other end as shown in FIG. Alternatively, for example, as shown in Figures 36(a) and (b), electromagnet coils (106, 108, 108B, 135, 136) may be connected between the neutral point of the polyphase winding and the DC bus midpoint or one leg midpoint of the inverter that supplies power to the polyphase winding. Note that in Figures 35, 36(a) and (b), elements similar to those in the first embodiment shown in Figures 2 and 3 are denoted by the same reference numerals.

[0200] In the example shown in Fig. 35, the first electromagnet coil (106) of the first thrust magnetic bearing (105) is connected between an end (an end of the U-phase winding in this example) of the first radial support winding (113) of the first bearingless motor (110) and the neutral point of the first motor winding (115). Here, a predetermined support current i zf When trying to flow a current from the first inverter (114) to the winding end of the U phase of the first radial support winding (113), in addition to the original motor drive current, i zf The current i ur_in At the end of the U-phase winding, a current i ur_in is branched, and the first electromagnet coil (106) is supplied with a supporting current i zf The supporting current i zf After flowing through the first electromagnet coil (106), it flows into the first motor winding (115). Therefore, the radial support current (i ur , i vr , i wr ) amplitude of I r , the phase is φ, and the motor drive current (i um , ivm , i wm ) amplitude of I m , with phase β, i ur_in =I r sin(φ)+i zr i ur =I r sin(φ) i vr =I r sin(φ+2π / 3) i wr =I r sin(φ+4π / 3) i um =I m sin(β)-i zf / 3 i vm =I m sin(β+2π / 3)-i zf / 3 i wm =I m1 sin(β+4π / 3)-i zf / 3 If the inverters (114, 116) are controlled so as to satisfy the above condition, a predetermined support current i can be supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) without adding any switching element. zf can be flushed.

[0201] In the example shown in FIG. 36(a), the first electromagnet coil (106) of the first thrust magnetic bearing (105) is connected between the neutral point of the first radial support winding (113) of the first bearingless motor (110) and the DC bus midpoint of the first inverter (114). In the example shown in FIG. 36(b), the first electromagnet coil (106) of the first thrust magnetic bearing (105) is connected between the neutral point of the first radial support winding (113) of the first bearingless motor (110) and the midpoint of one leg of the first inverter (114). Even in the configurations shown in FIGS. 36(a) and 36(b), a predetermined support current i can be supplied to the first electromagnet coil (106) of the first thrust magnetic bearing (105) by utilizing the zero-phase current without adding a switching element. zf can be flushed.

[0202] In the above embodiment, the multi-phase windings (113, 115, 123, 125) of the bearingless motors (110, 120) are used as the multi-phase windings for passing support currents to the electromagnet coils (106, 108, 108B) of the thrust magnetic bearings (105, 107) or the electromagnet coils (135, 136) of the radial magnetic bearings (130). However, the present invention is not limited to this. For example, a magnetic bearing system (100) as shown in FIG. 37 may be configured, and a motor winding (173) of a normal motor (170) may be used instead of the multi-phase windings (113, 115, 123, 125) of the bearingless motors (110, 120). Alternatively, a magnetic bearing system (100) as shown in FIG. 38 and FIG. 39 may be configured, and a reactor winding (181) of a reactor (180), which is an example of a stationary device, may be used. In addition, in Figs. 37 to 39, the same elements as those in the first or second embodiment shown in Figs. 1 to 3 and Fig. 8 are denoted by the same reference numerals.

[0203] The magnetic bearing system (100) shown in FIG. 37 differs from the second embodiment shown in FIG. 8 in that a normal motor (170) is provided instead of the first bearingless motor (110), and another radial magnetic bearing (140) is provided between the motor (170) and the thrust magnetic bearings (105, 107). That is, in the magnetic bearing system (100) shown in FIG. 37, two radial magnetic bearings (130, 140) are arranged to sandwich the motor (170) in the axial direction. The other radial magnetic bearing (140) is configured to support the radial load of the drive shaft (101) in a non-contact manner, similar to the radial magnetic bearing (130). The other radial magnetic bearing (140) is fixed to the inner circumferential wall of the pressure vessel (150). The diameter of a portion (141) of the rotating shaft (101) facing the other radial magnetic bearing (140) may be larger than the diameter of the other portions. The other radial magnetic bearing (140) has a stator (142) having a plurality of teeth (not shown) and an electromagnetic coil (145) wound around each of the teeth. The motor (170) has a rotor (171) and a stator (172). The rotor (171) is fixed to the drive shaft (101). The stator (172) is fixed to the inner peripheral wall of the pressure vessel (150). A plurality of permanent magnets (not shown) are embedded in the core of the rotor (171). The stator (172) has a plurality of teeth (not shown), and a motor winding (173) is wound around each of the teeth. The motor winding (173) generates a rotational torque in the rotating shaft (101) when power is supplied thereto. The motor winding (173) is a polyphase winding having three or more phases (for example, a three-phase winding having a U phase, a V phase, and a W phase).

[0204] The magnetic bearing system (100) shown in FIGS. 38 and 39 differs from the first embodiment shown in FIG. 1 mainly in that a reactor (180) having a reactor winding (181) is provided outside the pressure vessel (150). The reactor winding (181) is a polyphase winding having three or more phases (a three-phase winding in this example). One end of the winding of each phase of the reactor winding (181) is connected at a neutral point. A predetermined voltage is applied to the other end of the winding of each phase of the reactor winding (181) from the second inverter (116) in the same manner as the first motor winding (115). One end of the first electromagnet coil (106) of the first thrust magnetic bearing (105) is connected to the neutral point of the reactor winding (181), and the other end of the first electromagnet coil (106) is connected to the neutral point of the first motor winding (115). The reactor (180) is provided outside the pressure vessel (150) similarly to the inverter (only the second inverter (116) is shown in this example). Therefore, in order to apply a voltage from the second inverter (116) to the first motor winding (115), an airtight terminal (191) is provided to electrically connect the inside and outside of the pressure vessel (150), and an airtight terminal (192) is provided to connect the first electromagnet coil (106) of the first thrust magnetic bearing (105) and the reactor winding (181).

[0205] Note that a polyphase winding of another type of stationary device (e.g., a transformer) may be used instead of the reactor winding (181). Also, a reactor (180) may be provided in the magnetic bearing system (100) shown in Fig. 37, and the first electromagnet coil (106) of the first thrust magnetic bearing (105) may be connected between the neutral point of the reactor winding (181) of the reactor (180) and the neutral point of the motor winding (173) of the normal motor (170).

[0206] Although the embodiments have been described above, it will be understood that various modifications of the form and details are possible without departing from the spirit and scope of the claims. In addition, the above embodiments and modifications may be appropriately combined or substituted. [Industrial Applicability]

[0207] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for magnetic bearing systems, compressors, and refrigeration devices. [Explanation of symbols]

[0208] 1. Air conditioning equipment (refrigeration equipment) 10 Compressor 100 Magnetic Bearing System 101 Rotation axis 105 First thrust magnetic bearing (magnetic bearing or other magnetic bearing) 106 First electromagnet coil (electromagnet coil or other electromagnet coil) 107 Second thrust magnetic bearing (magnetic bearing or other magnetic bearing) 108 Second electromagnet coil (electromagnet coil or other electromagnet coil) 108A Second electromagnet coil (coil for other electromagnets) 108B Third electromagnet coil (electromagnet coil) 110 First bearingless motor (bearingless motor) 113 First radial support winding (first or second polyphase winding) 115 First motor winding (first or second polyphase winding) 120 Second bearingless motor (bearingless motor) 123 Second radial support winding (first or second polyphase winding) 125 Second motor winding (first or second polyphase winding) 130 Radial magnetic bearing (magnetic bearing) 135 Electromagnetic coils (other electromagnet coils) 136 Electromagnet Coil 137 Electromagnetic Coils (Other Electromagnetic Coils) 150 Pressure Vessels 173 Motor winding (1st or 2nd polyphase winding) 181 Reactor winding (1st or 2nd polyphase winding)

Claims

1. A magnetic bearing system (100) including a rotating shaft (101) and a magnetic bearing (105, 107, 130) having an electromagnet coil (106, 108, 108B, 135, 136), one end of the electromagnet coil (106, 108, 108B, 135, 136) is connected to a neutral point of a first multi-phase winding (113, 115, 123, 125, 173, 181) having at least three phases; The other end of the electromagnet coil (106, 108, 108B, 135, 136) is connected to a neutral point or an end of a second multi-phase winding (113, 115, 123, 125, 173, 181) having at least three phases different from the first multi-phase winding (113, 115, 123, 125, 173, 181). Magnetic bearing system.

2. 2. The magnetic bearing system (100) of claim 1, a bearingless motor (110, 120) including motor windings (115, 125) for generating a rotational torque on the rotating shaft (101) when power is supplied thereto, and radial support windings (113, 123) for generating a shaft support force for supporting the rotating shaft (101) in a non-contact manner when power is supplied thereto, the first polyphase winding (113, 115, 123, 125, 173, 181) is one of the motor winding (115, 125) and the radial support winding (113, 123); The second polyphase winding (113, 115, 123, 125, 173, 181) is the other of the motor winding (115, 125) and the radial support winding (113, 123). Magnetic bearing system.

3. The magnetic bearing system (100) of claim 2, The radial support winding (113, 123) is wound with short pitch winding, The winding pitch of the radial support winding (113, 123) is equal to or greater than half the number of slots of each pole of the radial support winding (113, 123). Magnetic bearing system.

4. 2. The magnetic bearing system (100) of claim 1, a first bearingless motor (110) including a first motor winding (115) that generates a rotational torque on the rotating shaft (101) when power is supplied thereto, and a first radial support winding (113) that generates a shaft supporting force for supporting the rotating shaft (101) in a non-contact manner when power is supplied thereto; a second bearingless motor (120) including a second motor winding (125) that generates a rotational torque on the rotating shaft (101) when power is supplied thereto, and a second radial support winding (123) that generates a shaft supporting force for supporting the rotating shaft (101) in a non-contact manner when power is supplied thereto, the first multi-phase winding (113, 115, 123, 125, 173, 181) is one of the first motor winding (115) and the first radial support winding (113); The second multi-phase winding (113, 115, 123, 125, 173, 181) is one of the second motor winding (125) and the second radial support winding (123). Magnetic bearing system.

5. 5. The magnetic bearing system (100) of claim 4, At least one of the first radial support winding (113) and the second radial support winding (123) is wound using short-pitch winding, The winding pitch of the radial support winding (113, 123) is equal to or greater than half the number of slots of each pole of the radial support winding (113, 123). Magnetic bearing system.

6. 2. The magnetic bearing system (100) of claim 1, the electromagnet coils (106, 108, 108B, 135, 136) and the first multi-phase windings (113, 115, 123, 125, 173) are disposed within the same pressure vessel (150); The one end of the electromagnet coil (106, 108, 108B, 135, 136) is connected to the neutral point of the first multi-phase winding (113, 115, 123, 125, 173) inside the pressure vessel (150). Magnetic bearing system.

7. 2. The magnetic bearing system (100) of claim 1, Further, the electromagnetic coil (106, 108, 108A, 135, 137) generates, with respect to the rotating shaft (101), an electromagnetic force in the same direction as or the opposite direction to the electromagnetic force generated with respect to the rotating shaft (101) by passing current through the electromagnet coil (106, 108, 108B, 136), The control band of the electromagnet coils (106, 108, 108B, 136) is configured to be lower than the control band of the other electromagnet coils (106, 108, 108A, 135, 137). Magnetic bearing system.

8. The magnetic bearing system (100) of claim 7, Further comprising another magnetic bearing (105, 107) having the other electromagnet coil (106, 108), A bias current is supplied to the electromagnet coils (106, 108), The direction of an electromagnetic force generated on the rotating shaft (101) by energizing the electromagnet coils (106, 108) is opposite to the direction of an electromagnetic force generated on the rotating shaft (101) by energizing the other electromagnet coils (106, 108). Magnetic bearing system.

9. The magnetic bearing system (100) of claim 7, the other electromagnet coil (108A, 137) is provided in the magnetic bearing (107, 130); A bias current is supplied to the electromagnet coil (108B, 136), The direction of an electromagnetic force generated on the rotating shaft (101) by energizing the electromagnet coils (108B, 136) is the same as the direction of an electromagnetic force generated on the rotating shaft (101) by energizing the other electromagnet coils (108A, 137). Magnetic bearing system.

10. 2. The magnetic bearing system (100) of claim 1, The magnetic bearings (105, 107, 130) are thrust magnetic bearings or radial magnetic bearings. Magnetic bearing system.

11. Equipped with a magnetic bearing system (100) according to any one of claims 1 to 10. Compressor.

12. The compressor (10) according to claim 11 is provided. Refrigeration equipment.

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