JP2003244891A - Flywheel battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flywheel battery that enables a rotating body to be stabilized at high revolution by using a non-contact bearing, such as a magnetic bearing. <P>SOLUTION: The flywheel battery is provided with a shaft, with its both ends being supported by the non-contact bearing and the rotating body comprising a flywheel fixed to the shaft. The shape of the rotating body is determined such that a ratio Ip/Id between moment of inertia Ip around the rotating shaft of the rotating body and moment of inertia Id about a shaft that is orthogonal to the rotating shaft and pass through the center of gravity of the rotating body is less than 1, and preferably 0.7 or in the vicinity thereof. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a flywheel
Regarding the battery.

[0002]

2. Description of the Related Art A rotating body supported by non-contact bearings at a plurality of axial positions, more specifically, a shaft having both ends supported by non-contact bearings, and a flywheel fixed to the shaft. A flywheel battery that includes a rotating body and stores electric energy as the rotating energy of the rotating body is disclosed in, for example, Japanese Patent Laid-Open No. 2000-253599.
It is proposed in the official gazette. In this conventional technique, a superconducting magnetic bearing is used as a non-contact type bearing,
It constitutes a so-called superconducting flywheel.

In a flywheel battery of this type, even if an actual rotating body is manufactured by precision processing, a slight deviation (eccentricity) remains between the geometric center and the center of gravity of the rotating body. The centrifugal force due to the eccentricity excites rotational vibration.
In the superconducting bearing structure according to the related art described above, since the bearing support rigidity with respect to the moment to tilt the rotating body is low, it is necessary to prevent the centrifugal force due to eccentricity from acting as a moment to tilt the rotating body. .

Therefore, in the above-mentioned prior art,
The length of the rotating body including the flywheel in the shaft direction is smaller than the outermost diameter of the rotating body, or the moment of inertia about the rotational symmetry axis of the rotating body is orthogonal to it.
It is made larger than the moment of inertia about the axis passing through the center of gravity of the rotor, in other words, the moment of inertia Ip about the axis of rotation of the rotor and the moment of inertia Id about the axis orthogonal to the axis of rotation and passing through the center of gravity of the rotor. In this prior art, the ratio Ip / Id of (shown by Ir) is configured to exceed 1.

[0005]

As described above, in the above-described conventional technique, the inertia moment ratio Ip / Id is made larger than 1 to reduce the moment for inclining the rotating body due to the centrifugal force caused by the eccentricity. However, as long as a non-contact type bearing such as a magnetic bearing is used, the damping ratio for rigid body resonance (conical mode) caused by its supporting characteristics decreases with increasing rotation due to the effect of the gyro effect. It becomes difficult to stabilize the rotating body at a high rotation because it changes (is unstable).

The degree of decrease of the damping ratio with respect to the rotational speed depends on the moment of inertia ratio, and the larger the ratio of inertia moment is, the greater the degree of decrease of the damping ratio becomes. Therefore, as proposed in the above-mentioned prior art, the moment of inertia ratio Ip
It is impossible to achieve high rotation with a rotating body having an / Id of more than 1.

Therefore, an object of the present invention is to solve the above-mentioned problems, and a flywheel battery capable of stabilizing a rotating body at a high rotation speed while using a non-contact type bearing such as a magnetic bearing. To provide.

[0008]

In order to achieve the above-mentioned object, in a first aspect of the present invention, there is provided a rotating body consisting of a flywheel supported by non-contact type bearings at a plurality of axial positions. In a flywheel battery that stores electric energy as rotation energy of the rotating body and outputs the accumulated rotation energy via a generator motor,
The shape of the rotating body is defined by a ratio Ip of an inertia moment Ip about the rotation axis of the rotating body and an inertia moment Id about the axis which is orthogonal to the rotation axis and passes through the center of gravity of the rotating body.
/ Id is set to be less than 1.

The shape of the rotating body has an inertia moment Ip about its rotation axis and a ratio Ip / I of an inertial moment Id about the axis which is orthogonal to the rotation axis and passes through the center of gravity of the rotating body.
Since d is determined to be less than 1,
It is possible to moderate the degree of decrease in the damping ratio for the conical mode in which the resonance frequency branches greatly as the rotation increases, and even when using non-contact type bearings such as magnetic bearings, stability at high rotation of the rotating body The energy density of the battery can be increased.

According to a second aspect of the present invention, the shape of the rotating body is determined so that the ratio of inertia moments Ip / Id is 0.7 or in the vicinity thereof.

The smaller the moment of inertia ratio, the smaller the degree of decrease in the damping ratio, but on the other hand,
Reducing the inertia moment ratio leads to lengthening of the shaft, which results in lowering the bending resonance frequency or increasing the weight of the flywheel battery body. Therefore, weigh such conflicting events,
The shape of the rotating body is determined so that the inertia moment ratio Ip / Id is 0.7 or in the vicinity thereof. As a result, even when a non-contact type bearing such as a magnetic bearing is used, it is possible to further stabilize the rotating body at a high rotation speed.

According to another aspect of the present invention, the displacement detecting means for detecting at least the displacement of the rotating body with respect to the magnetic bearing, more specifically, the displacement and the displacement speed of the rotating body with respect to the magnetic bearing, Rotation speed detecting means for detecting the rotation speed of the rotating body, and the magnetic field using a feedback gain obtained according to the rotation speed based on a predetermined feedback control rule so that the detected displacement becomes a target value. The feedback control means for calculating the operation amount to be supplied to the bearing is provided.

The operation amount to be supplied to the magnetic bearing, more specifically, by using the feedback gain obtained according to the rotation speed based on a predetermined feedback control law so that the detected displacement becomes a target value, more specifically, Since the feedback control means for calculating the energization command value to be supplied to the exciting coil of the electromagnet arranged in the stator of the magnetic bearing is provided, in other words, the displacement feedback corresponding to a spring / damper system in a mechanical system is provided. , More specifically,
Since the displacement feedback corresponding to the spring and the displacement speed feedback corresponding to the damper are configured to be performed for the magnetic bearing while using the gain adjusted according to the rotation speed, in addition to the effects described above, the spring is provided via the feedback gain. (Supporting rigidity) and damper (damping ratio) can be adjusted relatively easily, and a desired feedback law can be adjusted with respect to the rotational speed, and correction for a decrease in the damping ratio becomes possible. It is possible to further reduce the degree of decrease in the rotation speed, and it is possible to achieve better stabilization during high rotation of the rotating body.

[0014]

DETAILED DESCRIPTION OF THE INVENTION A flywheel battery according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the flywheel battery as a whole.

In FIG. 1, reference numeral 10 indicates the flywheel battery, and the flywheel battery 10
Comprises a housing 12. Inside the housing 12, a shaft 14 and a flywheel 20 formed by fixing (fastening) a bolt 16 to the shaft 14 by inserting a bolt 16 into a bolt insertion hole 16a are rotatably accommodated. In this way, the flywheel battery 10 is configured as a flywheel power storage device that uses the rotation of the flywheel 20 as stored energy.

The shaft 14 is made of an iron material and, as shown in the figure, is made up of shaft halves 14a and 14b. Both the shaft half portions 14a and 14b are the flywheel 2 from the tip end side.
The diameter is increased toward 0.

FIG. 2 is a top view of the flywheel 20.

As is apparent from FIG. 2, the flywheel 20 has a wheel shape in a top view, and the shaft halves 14 are provided on both sides of the central boss (hub) 20a (not visible in FIG. 2).
It is fixed (fastened) to a and 14b with bolts 16, and is thus configured to be rotatable via the shaft 14.

Between the boss 20a of the flywheel 20 and the annular rim 20b on the circumferential side, a plurality of (4) extending from the boss 20a toward the rim 20b with a predetermined space (90 degrees). The spokes (arms) 20c are integrally connected. Boss 20a, rim 20b and spokes 20c
Is made of aluminum material. Also, the rim 20b
Is relatively thin, and a rotor 20d made of a carbon fiber reinforced resin material is press-fitted and attached to the circumferential side thereof.

As shown in the figure, the rotor 20d has a donut shape in a top view, and is composed of a plurality of pieces, for example, five pieces, each of which is formed by laminating carbon fiber reinforced resin. Each piece is sequentially pressed into the outer periphery of the rim 20b.

As described above, since the rotor 20d is made of the carbon fiber reinforced resin, the rotor 20d can be lightweight and have high rotational strength. That is, the energy E is guided by E = (1/2) (Ip × ω ² ) [J], but the rotation angular velocity ω is increased by increasing the rotation strength, in other words, high-speed rotation is possible ( This rotation is fast and reaches tens of thousands of rpm). This makes it possible to realize a flywheel battery with high energy density.

Returning to the explanation of FIG. 1, a permanent magnet 22 is arranged on the outer periphery of the half portion 14b of the shaft 14, and the permanent magnet 2
2 to the shaft 14 with the filament winding layer 24
The rotor (rotor) 26 of the generator motor is wound on the upper side. On the other hand, a stator (stator winding) is provided in the housing 12 with a predetermined gap from the rotor 26.
30 is fixed. The rotor 26 and the stator 30 constitute a generator motor.

The shaft 14 (more specifically, the shaft halves 14a and 14b) is rotatably accommodated in the housing 12 via bearings 32 at both ends thereof. The bearing 32 is a non-contact type bearing, specifically, a magnetic bearing 32.

The magnetic bearing 32 includes a cylindrical rotor iron core (not shown) fixed to the shaft 14 and the housing 1.
2 includes a plurality of stators fixed to 2 and electromagnets (both not shown) arranged therein, and the rotor core is attracted radially by the electromagnets on the stator side to rotate the rotor 10
0 is supported in a non-contact manner. Displacement (position) of the rotor iron core with respect to the stator in the vicinity of the stator or the like, more generally, the shaft 14 or the rotating body 1 with respect to the magnetic bearing 32.
A displacement sensor (displacement detecting means) 34 that outputs a signal indicating the displacement of 00 and a rotation speed sensor 36 that indicates the rotation speed of the rotating body 100 are arranged.

The outputs of the displacement sensor 34 and the rotation speed sensor 36 are output from the controller 4 which is a microcomputer.
Sent to 0. The controller 40 detects the displacement (position) P of the rotor core with respect to the stator from the output of the displacement sensor 34, and obtains the differential value (or difference value) of the output to determine the displacement speed (the rotor core with respect to the stator, More generally, the displacement velocity V of the shaft 14 or the rotating body 100 with respect to the magnetic bearing 32 is detected. Further, the rotation speed N of the rotating body 100 is detected from the output of the rotation speed sensor 36.

As shown in FIG. 3, the controller 40 determines the displacement P and the displacement P determined according to the rotation speed N based on the feedback control law (PD control law, etc.) so that the detected displacement P matches the target value. Using an appropriate proportional (P) gain and derivative (D) gain with respect to the displacement speed V, an operation amount (energization command value) to be supplied to the exciting coil of the electromagnet arranged in the stator of the magnetic bearing 32 is calculated and driven. It is output via the unit 32a.

The inside of the housing 12 is connected to a decompression device (not shown) and is held in a vacuum so that the flywheel 20 can be maintained.
Is configured to reduce air resistance when rotating. still,
In the illustrated configuration, the shaft 14 and the flywheel 20 form the rotating body 100.

Thus, the flywheel battery 1
Reference numeral 0 denotes a rotor 100 composed of a flywheel 20 (and shaft 14) supported at a plurality of positions in the axial direction, specifically at two positions at both ends, and a rotor 26 and a stator 30.
Driven to operate as an electric motor to start rotation, electric energy is accumulated as rotational energy of the rotating body 100, and the accumulated rotational energy is used as a generator motor (rotor 2
6 and the stator 30). The output is taken out through a circuit (not shown) and provided for a desired application.

An object of the present invention is to provide a flywheel battery in which the non-contact type bearing is used, and the rotary body 100 can rotate stably even at high rotation speed. , I will explain it in detail.

FIG. 4 is an explanatory diagram showing the resonance frequency branching characteristic with respect to the rotation speed when the rotating body 100 is simply supported by a bearing having a fixed portion such as a mechanical bearing for simplification. It should be noted that the figure (a) shows the moment of inertia ratio Ip / Id>
If the value is 1, the figure (b) shows the moment of inertia ratio Ip / I.
The case where d <1 is shown.

Due to the gyro effect, the rotating body 100 has its own n-th-order bending resonance frequency which is higher with the increase in rotation (forward rotation mode frequency. Nutation (solid line)). ) And a low frequency (backward mode frequency. Precession (dashed line)).

Generally, in the rotating body 100 as shown,
The degree of branching of the resonance frequency due to the gyro effect is the inertia moment Ip about the rotation axis of the rotating body 100 and the inertia moment Id about the axis that is orthogonal to the rotation axis and passes through the center of gravity of the rotating body 100 (shown in FIG. 5). Is determined by the ratio Ip / Id. As is clear from comparison between FIGS. 3A and 3B, the larger the inertia moment ratio Ip / Id, the larger the branching of the resonance frequency due to the increase in rotation.

Since the gyro effect is an effect that appears with respect to the tilting motion of the rotating body, as shown in FIGS. 4 (a) and 4 (b),
The bending secondary resonance frequency at which the flywheel 20 is more inclined is greatly affected by the gyro effect, and its forward rotation mode frequency is asymptotic to (Ip / Id) · ω (ω: transport line (rotational angular velocity described above. Same as)).

As described above, since a slight eccentricity (unbalance) actually exists between the geometric center and the center of gravity of the rotating body 100, the centrifugal force due to this eccentricity causes rotational vibration. Cause. Since the centrifugal force due to the eccentricity acts on the rotating body 100 as a first-order rotation exciting force, the intersection of these resonance frequencies and the carrying line ω is called a bending critical speed. Although illustration is omitted, at the inertia moment ratio Ip / Id = 1, the asymptotic line described above coincides with the transportation line, and therefore at a high rotation speed, the critical speed state is always obtained.

In a high-speed rotating body such as the illustrated flywheel battery, overcoming this critical speed is a problem. In order to avoid the critical bending speed, it is effective to increase the rigidity of the rotating body 100 itself, that is, increase the rotating body bending resonance frequency so that the critical speed does not exist within the maximum rotation speed. For that purpose, it is effective to make the shaft 14 thicker and shorter, but at the same time, the moment of inertia ratio Ip / I
d becomes large.

Next, consider the case of being supported by the magnetic bearing 32.

Since the non-contact type bearing such as the magnetic bearing 32 has a lower supporting rigidity as compared with the mechanical type bearing, the rotating body 100 has a bending resonance and a lower frequency than that of the mechanical resonance. There are two types of rigid body resonances including a parallel (translational) mode and a conical (tilt) mode as shown in FIG.

7 to 9, the rotating body 100 is treated as a rigid body for simplification, and the shape of the rotating body 100 has inertia moment ratios Ip / Id> 1, Ip / Id = 1, Ip.
FIG. 9 is a simulation data diagram showing changes in the resonance frequency and the damper characteristic (attenuation ratio) of the parallel mode and the conical mode with respect to the rotation speed N when / Id <1.

As in the case of the simply supported bending resonance shown in FIG. 4, the rigid resonance appearing in the magnetic bearing support is also affected by the gyro effect, and as shown in FIG. To have. Concerning the bending secondary resonance, which largely diverges with the increase of the rotational speed as seen in FIG. 4, the conical resonance corresponds to this in the magnetic bearing support, and the bending 2
The conical forward resonance frequency (indicated by a one-dot chain line) instead of the next forward resonance frequency gradually approaches (Ip / Id) · ω.

As is clear from FIG. 7 and the like, the damper characteristic (attenuation ratio) is largely reduced for the conical forward rotation mode in which the resonance frequency changes greatly. This means that the conical forward rotation mode (rigid body resonance) changes in an unstable direction as the rotation speed increases.

In particular, as shown in FIG. 7, the inertia moment ratio Ip / Id> 1 of the rotating body 100, more specifically 1.3.
If it is set to a degree, the degree of deterioration of the damper characteristic (damping ratio) is remarkable, and high rotation cannot be achieved. When the inertia moment ratio Ip / Id of the rotating body 100 shown in FIG. 8 is set, the degree of decrease in the damping ratio is slightly improved as compared with the case shown in FIG. 7, but before the bending secondary resonance. As with the rotating mode, the asymptote of the resonance frequency is ω, so there is also a limit to the increase in rotation speed.

On the other hand, as shown in FIG. 9, the inertia moment ratio Ip / Id <1 of the rotating body 100, more specifically 0.6.
If it is set to a degree, the degree of decrease of the damping ratio will be gradual,
It is possible to ensure stability at high rotation speeds. Incidentally, in the case shown in FIG. 9, the conical critical speed N as indicated by reference signs a and b is shown.
a and Nb are present, but critical speeds Na and Nb
Since the damping ratio in the vicinity is large, it is easy to pass the critical speed.

As the inertia moment ratio Ip / Id becomes smaller, the degree of decrease in the damping ratio can be made smaller. On the other hand, making the inertia moment ratio smaller makes
Leading to a longer axial length of the shaft 14,
The bending resonance frequency is lowered, or the weight of the flywheel battery 10 as a whole is increased.

As a result of comparatively weighing such contradictory events, the inventors have found that the inertia moment ratio Ip / Id is 0.7.
Alternatively, it has been concluded that it is desirable to determine the shape of the rotating body 100 so as to be in the vicinity thereof. Thereby, even when a non-contact type bearing such as a magnetic bearing is used, it is possible to further stabilize the rotating body at a high rotation speed.

As described above, in the flywheel battery according to this embodiment, a non-contact type bearing such as the magnetic bearing 32 is used, and the shape of the rotating body 100 is set so that the inertia moment ratio Ip / Id is less than 1. Since it is preferably set to 0.7 or in the vicinity thereof, it is possible to stabilize the flywheel battery at the time of high rotation, and thus it is possible to realize a flywheel battery having a higher energy density.

Here, to determine the shape of the rotating body 100 so that the moment of inertia ratio is less than 1 or the like,
Specifically, the shaft 14 and the flywheel 20
This means not only determining the shape of the rotor 20d, for example, but also adjusting the specific gravity by changing the material.

Further, the rotational speed N of the magnetic bearing 32 is
Since the feedback control is performed based on the above, it is possible to correct the decrease in the damping ratio.
That is, if feedback control as shown in FIG. 3 is performed, PD control is performed on the energization command value to the exciting coil of the electromagnet of the stator of the magnetic bearing 32 so that the displacement P of the rotor core with respect to the stator matches the target value. In the mechanical system, the displacement feedback corresponds to the spring and the displacement velocity feedback corresponds to the damper. However, since the gyro effect to be solved is a function of the rotation speed N of the rotating body 100, the rotation speed is set in this embodiment. The feedback gains of the displacement P and the displacement speed V are adjusted according to N. The feedback gain may be set in advance according to the rotation speed N, or may be calculated in real time.

FIG. 10 is a graph generally showing the change of the damping ratio with respect to the rotation speed N. If feedback control is performed by the rotation speed and the displacement as in this embodiment, for example, in FIG. As shown by the solid line in the figure, the decrease in the damping ratio can be slowed down and moderated as shown by the arrow, as compared with the case of "countermeasure" indicated by the broken line. Further, the spring (supporting rigidity) and the damper (damping ratio) can be adjusted relatively easily via the feedback gain.

Although the rotating body 100 is treated as a rigid body for simplification in FIGS. 7 to 9, even if it is treated as an elastic body, only a slight difference occurs in the asymptote or the like, and the above tendency is large. There is no difference.

In this embodiment, as described above, a non-contact type bearing (magnetic bearing 32) is provided at a plurality of positions in the axial direction.
A rotary body 100 including a flywheel 20 (which is fixed to the shaft 14 and a shaft 14) supported by the rotary body 100 is stored, electric energy is accumulated as the rotary energy of the rotary body, and the accumulated rotary energy is used as a generator motor (stator 2).
6. In the flywheel battery 10 that outputs through the rotor 30), the shape of the rotating body 100 is orthogonal to the rotating shaft and the inertia moment Ip about the rotating shaft of the rotating body, and The ratio Ip / Id of the inertia moment Id about the axis passing through the center of gravity is set to be less than 1.

Further, the shape of the rotating body 100 is determined so that the ratio Ip / Id of the inertia moment is 0.7 or in the vicinity thereof.

Further, at least the displacement P of the rotating body 100 (shaft 14) with respect to the magnetic bearing 32, specifically the displacement P and the displacement speed V, more specifically, the displacement of the rotor core with respect to the stator of the magnetic bearing 32. Displacement detecting means for detecting P and displacement speed V, rotating speed detecting means for detecting the rotating speed of the rotating body (displacement sensor 34, controller 40), rotating speed detecting means for detecting the rotating speed of the rotating body 100 (rotating body). Number sensor 36, controller 4
0), and the operation amount to be supplied to the magnetic bearing is calculated using a feedback gain obtained according to the rotation speed based on a predetermined feedback control law so that the detected displacement becomes a target value. The feedback control means (controller 40) is provided.

Although a magnetic bearing is shown as an example of the non-contact type bearing in the above, the bearing is not limited to this, and a bearing using a fluid such as air as a medium may be used.

Further, in the above description, as the flywheel battery, the inner rotor type in which the rotor 26 and the rotor core are arranged inside the stator 30 of the generator motor fixed to the housing 12 and the stator of the magnetic bearing 32 in the radial direction is shown. May be an outer rotor type in which a rotor 26 and a rotor iron core are arranged radially outside the stator 30 of the generator motor fixed to the housing 12 and the stator of the magnetic bearing 32, and one of them is an inner rotor. A composite type of a rotor type and an outer rotor type may be used.

[0056]

According to the first aspect of the present invention, the shape of the rotating body has an inertia moment Ip about its rotation axis and an inertial moment Id about the axis orthogonal to the rotation axis and passing through the center of gravity of the rotation body. Since the ratio Ip / Id is determined to be less than 1, it is possible to moderate the degree of decrease in the damping ratio with respect to the conical mode in which the resonance frequency branches greatly as the rotation increases, and the magnetic bearing Even when a non-contact type bearing such as the above is used, stabilization of the rotating body at high rotation speed can be realized, and thus the energy density of the battery can be increased.

According to the second aspect, the degree of decrease in the damping ratio can be made smaller as the inertia moment ratio is made smaller. On the other hand, making the inertia moment ratio smaller leads to lengthening of the shaft. The bending resonance frequency is lowered, or the weight of the flywheel battery body is increased. Therefore, such a contradictory phenomenon is comparatively weighed, and the shape of the rotating body is determined so that the inertia moment ratio Ip / Id becomes 0.7 or in the vicinity thereof. As a result, even when a non-contact type bearing such as a magnetic bearing is used, it is possible to further stabilize the rotating body at a high rotation speed.

According to the third aspect of the present invention, the detected displacement is supplied to the magnetic bearing by using a feedback gain obtained according to the rotational speed based on a predetermined feedback control law so that the detected displacement becomes a target value. Since it is configured so as to have a feedback control means for calculating an energization amount, more specifically, an energization command value to be supplied to the exciting coil of the electromagnet arranged in the stator of the magnetic bearing, in other words, in the mechanical system. Displacement feedback corresponding to a spring / damper system, more specifically, displacement feedback corresponding to a spring and displacement velocity feedback corresponding to a damper are performed for a magnetic bearing while using a gain adjusted according to the number of revolutions. Since it is configured, in addition to the effects described above, a spring (supporting rigidity) is provided via feedback gain.
And the damper (damping ratio) can be adjusted relatively easily, and the desired feedback law can be adjusted with respect to the number of revolutions, and the decrease in the damping ratio can be corrected and the degree of decrease in the damping ratio can be adjusted. It can be made more gradual, and the stabilization of the rotating body at high rotation speed can be further realized.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a flywheel battery including a rotating body such as a flywheel according to an embodiment of the present invention.

FIG. 2 is a top view of the flywheel shown in FIG.

FIG. 3 is a block diagram showing feedback control of the magnetic bearing shown in FIG.

FIG. 4 is an explanatory diagram showing resonance frequency branching characteristics with respect to rotation speed for each inertia moment ratio when the rotating body shown in FIG. 1 is simply supported by a bearing having a fixed portion such as a mechanical bearing for simplification.

5 is an explanatory diagram showing an inertia moment ratio used in FIG. 4 and the like.

FIG. 6 is an explanatory diagram illustrating rigid body resonance that acts on the rotating body illustrated in FIG. 1.

FIG. 7 treats the rotating body shown in FIG. 1 as a rigid body for the sake of simplification, and changes its shape into a moment of inertia ratio Ip / Id> 1.
FIG. 6 is a simulation data diagram showing changes in the resonance frequency and the damping ratio of the parallel mode and the conical mode in the case of.

FIG. 8 is a simulation data diagram similar to FIG. 7 when the inertia moment ratio Ip / Id = 1.

9 is a simulation data diagram similar to FIG. 7 when the moment of inertia ratio Ip / Id <1.

FIG. 10 is a graph generally showing a change of a damping ratio with respect to a rotation speed for explaining an effect of the feedback control shown in FIG.

[Explanation of symbols]

10 Flywheel / Battery 14 Shaft 20 Flywheel 22 Permanent magnet 26 Rotor 30 (of generator motor) Stator 32 (of generator motor) Magnetic bearing 34 Displacement sensor (displacement detection means) 36 Rotation speed sensor (rotation speed detection means) 40 Controller (Displacement and Rotation Speed Detection Means and Feedback Control Means) 100 Rotating Body

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koichi Ono             1-4-1 Chuo Stock Market, Wako City, Saitama Prefecture             Inside Honda Research Laboratory (72) Inventor Yukihiko Itai             1-4-1 Chuo Stock Market, Wako City, Saitama Prefecture             Inside Honda Research Laboratory F term (reference) 3J102 AA01 BA03 BA17 CA02 CA22                       DA03 DA09 DA18 DB05 DB06                       DB08 DB37 GA09                 5H607 AA04 AA14 BB02 BB07 BB14                       BB25 CC09 DD02 DD16 EE42                       GG17 GG29 HH01 HH03

Claims (3)

[Claims] 1. A rotary body comprising a flywheel supported by non-contact bearings at a plurality of axial positions, the electric energy is accumulated as the rotary energy of the rotary body, and the accumulated rotary energy is used as a generator motor. In the flywheel battery output via the above, the shape of the rotating body is set to the inertia moment Ip about the rotation axis of the rotating body.
And a flywheel battery which is determined so that a ratio Ip / Id of an inertia moment Id about an axis passing through the center of gravity of the rotating body while being orthogonal to the rotation axis is less than 1. 2. The flywheel battery according to claim 1, wherein the shape of the rotating body is determined so that the ratio of inertia moments Ip / Id is 0.7 or in the vicinity thereof. 3. Further comprising: a. Displacement detecting means for detecting at least displacement of the rotating body with respect to the magnetic bearing, b. Rotation speed detection means for detecting the rotation speed of the rotating body, and c. Feedback control means for calculating an operation amount to be supplied to the magnetic bearing by using a feedback gain obtained according to the rotation speed based on a predetermined feedback control law so that the detected displacement becomes a target value, The flywheel battery according to claim 1 or 2, further comprising: