JPH10205536A - Rotational loss measuring device of superconductive bearing part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure the rotational loss by supporting a rotor in the specified position by radial and axial magnetic bearing parts in the non-contact state, rotating the rotor by a rotational driving electric motor at the specified revolutions, stopping the electric motor, freely rotating the rotor, and detecting the change of the rotational speed. SOLUTION: A rotor 1 is supported in the specified position in the non-contact state by upper and lower radial magnetic bearing parts 3, 4 and an axial magnetic bearing part 5, and the rotor 1 is floated in relation to a fixed part A. The rotor 1 is rotated by an electric motor at the spevidied revolutions, the electric motor 6 is stopped, the rotational body 1 is freely rotated, the change of the rotational speed is detected by a rotational speed sensor 7, and the first rotational loss is found. At this time, cooling fluid is not supplied to a tank 18 of a superconductive bearing part 2, and a superconductor 19 in the tank 18 is exposed to the ordinary temperature. Next, cooling fluid is circulated in the tank 18, the superconductor 19 is cooled to the specified temperature, and the second rotational loss is found. The rotational loss of the superconductive bearing part can be found by the difference between both rotational losses.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation loss measuring device for a superconducting bearing provided in a power storage device for storing, for example, surplus power into kinetic energy of a flywheel.

[0002]

2. Description of the Related Art As a power storage device, a vertical rotating body, a flywheel fixedly provided on the rotating body, a rotor section provided on the rotating body, and a rotor section provided on a fixed section are provided around the rotor section. A rotary drive motor comprising a stator portion arranged, an annular permanent magnet portion provided concentrically and fixedly to the rotating body, and an annular superconductor portion arranged on the fixed portion so as to face the permanent magnet portion. (Japanese Patent Laid-Open No. Hei 4-370417).
No.).

In such a power storage device, in order to efficiently extract kinetic energy stored in a flywheel as electric energy at the time of a power failure, it is necessary to reduce the rotational loss of the superconducting bearing.

However, conventionally, the rotational loss of the superconducting bearing has not been clarified, and there has been no rotational loss measuring device having a sufficient function. Therefore, in order to determine optimal specifications of the annular permanent magnet portion and the annular superconductor portion in the superconducting bearing portion for efficiently extracting kinetic energy stored in the flywheel as electric energy, the actual power storage device must be operated. In addition, the operation of stopping the motor and extracting the kinetic energy stored in the flywheel as electric energy needs to be performed by variously changing the specifications of the annular permanent magnet portion and the annular superconductor portion in the superconducting bearing portion. As a result, there is a problem that the operation is troublesome.

Therefore, the present applicant has proposed a vertical rotating body,
A superconducting bearing portion comprising an annular permanent magnet portion attached concentrically to the rotating body and an annular superconductor portion attached to the fixed portion so as to face the permanent magnet portion; and a superconducting bearing portion axially separated from the superconducting bearing portion and mutually separated from each other. A control-type radial magnetic bearing portion that is provided at two different height positions and controls two radial positions of the rotating body orthogonal to each other, and a permanent that floats the rotating body in a non-contact state with respect to the fixed portion. A magnet, a rotation driving motor including a rotor portion provided on the rotating body and a stator portion provided on the fixed portion and arranged around the rotor portion, and a rotation speed sensor for detecting a rotation speed of the rotating body. (See Japanese Patent Application Laid-Open No. 8-86703).

According to this device, before incorporating the superconducting bearing into an actual device such as a power storage device, the rotational loss of the superconducting bearing is determined to determine the annular permanent magnet portion and the annular superconductor constituting the superconducting bearing. It is possible to determine the optimal design specification of the section.

When the rotational loss of the superconducting bearing is measured by using the above-described apparatus, the axial (vertical) load applied to the superconducting part may be measured in a wide range. desired.

In the above device, since the rotating body is levitated with respect to the fixed portion by the upward repulsive force of the permanent magnet,
The load that can be applied to the superconducting bearing portion cannot be changed other than the weight of the rotating body. Further, since the rotating body is supported in the axial direction by the repulsive force of the permanent magnet, there is a possibility that the rotating body may be vibrated in the axial direction and an error may occur in the measurement.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to vary the load applied to the superconducting bearing in a wide range in order to optimally design the superconducting bearing. It is an object of the present invention to provide a device capable of accurately measuring the rotation loss of a motor.

[0010]

The apparatus according to the present invention comprises a vertical rotating body, an annular permanent magnet section concentrically mounted on the rotating body, and a fixed section facing the permanent magnet section. A superconducting bearing portion comprising an annular superconducting portion attached to the rotor, and two radial positions orthogonal to each other of the rotating body which are respectively provided at two different height positions axially separated from the superconducting bearing portion and mutually orthogonal. A control-type radial magnetic bearing for controlling, a control-type axial magnetic bearing for floating the rotating body in a non-contact state with respect to the fixed part, a rotor provided on the rotating body and a rotor provided on the fixed part And a rotation drive motor including a stator portion disposed around the portion, and a rotation speed sensor for detecting a rotation speed of the rotating body.

In this device, the rotation loss of the superconducting portion is measured as follows.

First, the rotating body is non-contactly supported at a predetermined position in the radial direction (horizontal direction) by two upper and lower radial magnetic bearing portions, and the rotating body is moved in the axial direction (vertical direction) by the axial magnetic bearing portion. The rotating body is floated in a non-contact state with respect to the fixed portion by supporting the rotating body in a non-contact state at a predetermined position, and then the rotating body is rotated at a predetermined rotation number by operating a rotation driving motor. After that, the motor is stopped and the rotating body is freely rotated. At this time, a change in the rotation speed is detected by a rotation speed sensor, and the first data is obtained by using the data.
The rotation loss of At this time, the superconductor of the annular superconductor portion of the superconducting bearing is kept in a normal conducting state at room temperature, and the superconducting bearing is in a non-operating state.

On the other hand, in the same manner as described above, after the rotor is floated in a non-contact state by the radial magnetic bearing portion and the axial magnetic bearing portion, the superconductor of the annular superconductor portion of the superconducting bearing portion is cooled to a predetermined temperature. To maintain the superconducting state. Thereafter, the position of the superconductor portion of the superconducting bearing portion is changed in the axial direction. As a result, the superconducting bearing is brought into an operating state, but the rotating body is supported in a non-contact manner in the radial and axial directions by the control type magnetic bearing. Next, the rotation driving motor is operated to rotate the rotating body at the same rotation speed as described above. Thereafter, the electric motor is stopped and the rotating body is freely rotated. At this time, a change in rotation speed is detected by a rotation speed sensor, and a second rotation loss is obtained using the data.

Then, the rotation loss of the superconducting bearing portion is obtained by subtracting the first rotation loss from the second rotation loss.

When the second rotational loss is determined, the axial magnetic bearing is operated as it is even after the superconducting bearing is activated, and the weight of the rotating body is supported by the axial magnetic bearing. The axial load applied to the superconducting bearing is almost zero. If the superconductor portion of the superconducting bearing portion is moved downward or upward, the load applied to the superconducting bearing portion can be made larger or smaller than its own weight depending on the amount of movement. Therefore, the load applied to the superconducting bearing portion can be variously changed over a wide range. Further, since the axial position of the rotating body is controlled by the control type axial magnetic bearing, the axial vibration of the rotating body can be reduced, and thus accurate measurement can be performed.

According to the device of the present invention, before the superconducting bearing is incorporated into an actual device such as a power storage device, the load applied to the superconducting bearing is changed over a wide range as described above. The rotation loss of the part can be determined accurately. Therefore, before incorporating the superconducting bearing into an actual device, it is possible to determine the optimal design specifications of the annular permanent magnet and the annular superconductor constituting the superconducting bearing,
Unlike the conventional case, it is not necessary to operate an actual device having a superconducting bearing portion by changing the specifications of the annular permanent magnet portion and the annular superconductor portion constituting the superconducting bearing portion in various ways. The work of determining the optimum specifications of the annular permanent magnet portion and the annular superconductor portion to be performed is greatly simplified.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an entire schematic configuration of an embodiment of a rotation loss measuring device for a superconducting bearing according to the present invention.

The rotation loss measuring device is a rotating member having a vertical axis.
(1), superconducting bearing part (2), upper and lower two control type radial magnetic bearing parts (3) (4), control type axial magnetic bearing part
(5), rotation drive motor (6) and rotation speed sensor (7)
These are arranged inside the upper housing (8) and the lower housing (9) constituting the fixed portion (A). The upper housing (8) has a vertically long vertical cylindrical shape, and the lower housing (9) has a larger diameter and a relatively short vertical cylindrical shape. Upper and lower housing (8)
(9) is formed integrally by combining a plurality of components.

In the following description, the axis in the axial direction (vertical axis) is the Z axis, and one axis in the radial direction (horizontal axis) orthogonal to the Z axis is the X axis, and the radial axis orthogonal to the Z axis and the X axis. The axis of the direction (horizontal axis) is the Y axis.

The rotating body (1) is arranged concentrically in the center of the upper housing (8), and its lower part projects into the lower housing (9).

The superconducting bearing portion (2) is for supporting the rotating body (1) in a non-contact manner in the radial direction and the axial direction, and is an annular permanent magnet mounted concentrically below the rotating body (1). An annular superconductor section (11) attached to the fixed section (A) so as to face the section (10) and the permanent magnet section (10). The horizontal support disk (12) is fixed to the lower end surface of the rotating body (1) projecting into the lower housing (9), and the permanent magnet part (10) is detachably fixed to the lower surface. . The permanent magnet part (10) is disc (12) concentric with the rotating body (1).
Vertical cylindrical support tube (13) detachably fixed to the lower surface of
A plurality of upper and lower annular permanent magnets (14) are arranged on the inner periphery of the support cylinder (13) via an annular spacer (15), and are fixed to a lower end surface of the support cylinder (13). It is fixed by a stop member (16). For example, each of the permanent magnets (14) has magnetic poles on both end surfaces in the axial direction, and is arranged such that the magnetic poles of the permanent magnets (14) vertically adjacent to each other have the same polarity. In this case, if the spacer (15) is an iron yoke, this yoke becomes a magnetic pole. The permanent magnet (14) is arranged concentrically with the rotating body (1), and the magnetic flux distribution of the permanent magnet (14) around the rotation axis of the rotating body (1) changes due to the rotation of the rotating body (1). Not to be done. Although detailed illustration is omitted,
A vertical support shaft (17) concentric with the rotating body (1) is provided at an appropriate position below the fixed portion (A) so that the position in the vertical direction can be adjusted. The upper part of the support shaft (17) is the lower housing
The superconductor section (11) is detachably fixed to the upper end surface of the support shaft (17) through the bottom wall of (9). On the other hand, if a load cell (not shown) is fixed to the lower end surface of the support shaft (17), the load on the superconducting bearing (2) can be measured by this load cell. The superconductor section (11) includes an annular cooling tank (18) removably fixed to the upper end surface of the support shaft (17) so as to be concentric with the rotating body (1). The tank (18) has a vertical double cylindrical shape, and its upper part is fitted inside the permanent magnet (14) of the permanent magnet part (10) with a slight gap in the radial direction.
A portion of the outer peripheral wall of the tank (18) facing the permanent magnet (14) is thinner, and a vertical cylindrical type 2 superconductor (19) is provided in the tank (18) inside the portion. Fixed.
The superconductor (19) is arranged concentrically with the rotating body (1), and the permanent magnet (14) passes through the thin peripheral wall of the tank (18) and the air gap.
And in the radial direction. The superconductor (19) is, for example, an yttrium-based superconductor, for example, Y ₁ Ba ₂ Cu
Normally conductive particles (Y ₂ Ba) are contained in the bulk of ₃ O _7-x
1 Cu ₁ ) is uniformly mixed, and has a property of restraining the intrusion of magnetic flux emitted from the permanent magnet (14) in an environment in which the type 2 superconducting state appears. By arranging the superconductor (19) as described above, the distribution of the invading magnetic flux is at a separated position where the magnetic flux of the permanent magnet (14) invades by a predetermined amount and the rotation of the rotating body (1). It is located in a position that does not change. Although not shown, the tank (18) is connected to a suitable cooling device,
With this cooling device, a cooling fluid made of, for example, liquid nitrogen is circulated in the tank (18), and the superconductor (19) is cooled by the cooling fluid filled in the tank (18).

The radial magnetic bearings (3) and (4) are
(1) in a non-contact manner and for controlling the position of the rotating body (1) in two radial directions (X-axis and Y-axis directions) perpendicular to each other. It is provided in the place. The radial magnetic bearings (3) and (4) are fixed in the housing (8) so as to sandwich the rotating body (1) from both sides in the X-axis direction, and place the rotating body (1) on both sides in the X-axis direction. A pair of X-axis electromagnets (20x) to be attracted and a housing (8) sandwiching the rotating body (1) from both sides in the Y-axis direction
And a pair of Y-axis direction electromagnets (not shown) that are fixed inside and attract the rotating body (1) to both sides in the Y-axis direction. In the vicinity of the electromagnet (20x) of each radial magnetic bearing (3) (4),
Housing so that the rotating body (1) is sandwiched from both sides in the X-axis direction
An X-axis displacement sensor (21x) fixed to (8) and detecting the displacement of the rotating body (1) in the X-axis direction, and a housing (8) so as to sandwich the rotating body (1) from both sides in the Y-axis direction. And a Y-axis direction displacement sensor (not shown) for detecting the displacement of the rotating body (1) in the Y-axis direction. Each electromagnet (20x) and each displacement sensor (21x) in each radial magnetic bearing (3) (4)
Is connected to a control device (not shown), and a constant steady current and a control current are supplied to each electromagnet (20x) from the control device. Then, the control device controls the magnitude of the control current supplied to each electromagnet (20x) based on the output signal of each displacement sensor (21x), whereby the magnetic attraction force of each electromagnet (20x) is controlled. Thus, the position of the rotating body (1) in the X-axis and Y-axis directions is controlled. The rotating body (1) is normally supported in a non-contact manner at the center of the housing (8) by radial magnetic bearings (3) and (4).

The axial direction magnetic bearing portion (5) includes a rotating body.
Control the position of (1) in the Z-axis direction and fix the rotating body (1)
This is for floating in a non-contact state with respect to (A), and is provided near the upper end in the upper housing (8). Near the upper end of the rotating body (1), a horizontal outward flange
(22) is fixed. Axial magnetic bearing (5)
The rotating body (1) is fixed inside the housing (8) so that the portion of the flange (22) near the outer circumference is sandwiched from both sides in the Z-axis direction.
A pair of upper and lower Z-axis electromagnets for attracting to both sides in the Z-axis direction
(23a) and (23b) are provided. A Z-axis direction displacement sensor (24) for detecting the displacement of the rotating body (1) in the Z-axis direction is provided at an appropriate location in the housing (8), for example, at the upper part. The electromagnets (23a) (23b) and the Z-axis direction displacement sensor (24) of the axial magnetic bearing (5) are connected to the above-mentioned control device, and the control device sends the electromagnets (23a) (23b) to the respective electromagnets (23a) (23b). A constant steady current and control current are supplied. And the control device:
Based on the output signal of the displacement sensor (24), each electromagnet (23a) (23
b) controlling the magnitude of the control current supplied to
The position of the rotating body (1) in the Z-axis direction is controlled.

The electric motor (6) is for rotationally driving the rotating body (1), and includes upper and lower radial magnetic bearings (3).
It is provided in the middle part of the upper housing (8) between (4). The electric motor (6) has a rotor (25) provided on the outer periphery of the rotating body (1) and a stator (26) fixed in the housing (8) and arranged around the rotor (25). ).

The inner peripheral portion of the casing of the lower Z-axis direction electromagnet (23b) in the upper housing (8) and the upper housing
Mechanically supports the rotating body (1) on the inner periphery near the lower end of (8) when the superconducting bearing (2) and magnetic bearings (3), (4), (5) are no longer supported Touch-down bearings for (2
7) (28) is installed.

The rotational speed sensor (7) is for detecting the rotational speed of the rotating body (1), and is provided at an appropriate place in the housing (8), for example, at the upper part.

In the above apparatus, the measurement of the rotational loss of the superconducting bearing portion is performed, for example, as follows.

First, upper and lower radial magnetic bearings (3)
By operating (4), the rotating body (1) is supported in a predetermined position in the radial direction in a non-contact manner, and the axial direction magnetic bearing
(5) is operated to support the rotating body (1) at a predetermined position in the axial direction in a non-contact manner, and to float the rotating body (1) in a non-contact state with respect to the fixed portion (A). Next, the electric motor (6) is operated to rotate the rotating body (1) at a predetermined number of revolutions. Thereafter, the motor (6) is stopped and the rotating body (1) is freely rotated. The change in the rotating speed at this time is detected by the rotating speed sensor (7), and the first rotation loss is obtained using the data. At this time, no cooling fluid is supplied to the tank (18) of the superconducting bearing (2). For this reason, the superconductor (19) in the tank (18) is maintained at normal temperature and in a normal conduction state where the second superconducting state does not appear, and the superconducting bearing (2) is in a non-operating state where no supporting force is generated. ing. Therefore, no rotation loss occurs in the superconducting bearing portion (2).

Next, similarly to the above, the radial magnetic bearing portions (3) and (4) and the axial magnetic bearing portion (5) are used to rotate the rotating body.
After floating (1) in a non-contact state, a cooling fluid is circulated in the tank (18) of the superconducting bearing (2), and the superconductor (19) in the tank (18) is cooled to a predetermined temperature. , The second superconducting state is maintained in the appearing superconducting state. When the superconductor (19) is cooled (magnetic field cooled) into the second type of superconducting state while the magnetic flux generated from the permanent magnet (14) has penetrated into the superconductor (19), the superconductor (19) Most of the magnetic flux that has penetrated into the inside of the superconductor (19) is restrained inside the superconductor (19) as it is (pinning phenomenon). Here, since the superconductor (19) is a mixture of normal conductor particles uniformly inside the superconductor (19), the distribution of magnetic flux penetrating into the superconductor (19) is constant, so that it is as if the superconductor (19) The permanent magnet (14) penetrates the pin set up in (). As a result, the superconducting bearing portion (2) enters an operating state in which a force is generated when the relative position between the permanent magnet (14) and the superconductor (19) changes. Therefore, if the support shaft (17) is moved upward or downward, a certain load can be generated on the superconducting bearing portion (2) accordingly. This load can be measured by disposing a load cell on the support shaft (17). At this time, the control type magnetic bearing
(3) Since all the directions (X, Y and Z axis directions) are controlled in (4) and (5), the rotating body (1) is supported in the axial and radial directions while being extremely stably levitated. Will be. When a certain load is generated in the superconducting bearing (2), the motor (6) is operated to rotate the rotating body (1) at the same rotational speed as described above. Thereafter, the motor (6) is stopped, and the rotating body (1) is freely rotated. A change in the rotating speed at this time is detected by the rotating speed sensor (7), and the second data is obtained by using the data.
The rotation loss of At this time, the magnetic flux that has entered the superconductor (19) does not ideally become a resistance that hinders rotation as long as the magnetic flux distribution is uniform and invariant with respect to the rotation axis of the rotating body (1). If there is a loss in the superconducting bearing (2), the loss is added.

Then, by subtracting the first rotational loss from the second rotational loss, the rotational loss of the superconducting bearing portion (2) is obtained. However, at this time, at the time of the second rotation loss measurement and the first rotation loss measurement, the control type magnetic bearing part (3) (4) (5)
If the control conditions are different, it means that the loss due to the change has changed, but this value can be corrected by calculation.

As described above, when obtaining the second rotation loss,
When the superconducting bearing (2) is activated, the rotating body (1)
Is supported by an axial bearing (5). When the weight of the rotating body (1) is supported by the axial magnetic bearing portion (5), the axial magnetic bearing portion (5) generates an upward magnetic attraction force as a whole. In such a state, if the load applied to the superconducting bearing portion (2) is gradually increased, the upward attractive force of the entire axial direction magnetic bearing portion (5) gradually decreases. When the attractive forces of the upper and lower electromagnets (23a) and (23b) of the axial magnetic bearing (5) are equal to each other, the load applied to the superconducting bearing (2) is made equal to the weight of the rotating body (1). be able to. Further, the support shaft (17) can be moved until the load applied to the superconducting bearing portion (2) becomes larger than the weight of the rotating body (1). in this way,
Although the attractive force of the axial magnetic bearing (5) varies, the load applied to the superconducting bearing (2) is
(1) It can be variously changed over a wide range below or above the weight of the superconducting bearing part.
In various states where the load applied to (2) is changed, the rotational loss of the superconducting bearing (2) can be measured. The value of the load of such a superconducting bearing (2) can be measured by a load cell, but the attractive force of the axial magnetic bearing (5) changes with this value.
It is also possible to measure the amount of change in the control current of the electromagnets (23a) (23b) generating the attraction force, and convert this value into a load. In this case, no load cell is required.

Further, since the axial position of the rotating body (1) is controlled by the control type axial magnetic bearing (5), the axial vibration of the rotating body (1) can be reduced. , Accurate measurement becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a rotation loss measuring device for a superconducting bearing unit according to an embodiment of the present invention.

[Explanation of symbols]

 (1) Rotating body (2) Superconducting bearing (3) (4) Radial magnetic bearing (5) Axial magnetic bearing (6) Rotary drive motor (7) Rotation speed sensor (10) Annular permanent magnet (11) Annular superconductor part (14) Permanent magnet (19) Superconductor (25) Rotor part (26) Stator part (A) Fixed part

Claims (1)

[Claims] 1. A superconducting bearing portion comprising a vertical rotating body, an annular permanent magnet portion concentrically attached to the rotating body, and an annular superconductor portion attached to a fixed portion to face the permanent magnet portion. A control-type radial magnetic bearing portion, which is provided at two different height positions axially separated from the superconducting bearing portion and controls two orthogonal radial directions of the rotating body, and a rotating body. For a rotational drive comprising a control type axial magnetic bearing part which floats in a non-contact state with respect to the fixed part, a rotor part provided on the rotating body and a stator part provided on the fixed part and arranged around the rotor part. A rotation loss measuring device for a superconducting bearing unit, comprising a motor and a rotation speed sensor for detecting a rotation speed of a rotating body.