JPH1127975A - Vibration control device for rotating electric machine - Google Patents

Abstract

(57) [Problem] An object of the present invention is to provide a vibration control of a rotating electric machine capable of adding a damping force to vibration of a rotating shaft at a critical speed of the rotating shaft and operating an electric motor stably exceeding the critical speed. It is to provide a device. SOLUTION: The present invention sets a rotation frequency of a rotor to ω _M ,
When the electric frequency of the rotating magnetic field generated by the main winding is ω, an attenuation control winding that generates a rotating magnetic field of ω _M + ω is provided separately from the main winding, and the critical speed of the rotating shaft of the rotating electric machine is reduced. The damping force is applied to the vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control device for suppressing vibration of a rotor of a rotating machine such as a permanent magnet motor or an induction motor.

[0002]

2. Description of the Related Art As these rotary electric machines rotate at high speed, vibration of a rotating shaft due to a higher-order vibration mode (bending vibration) becomes a serious problem. The prior art will be described with reference to the drawings. FIG. 15 is an axial sectional view showing a configuration of a general AC motor. In the figure, reference numeral 1 denotes a rotating shaft, and a rotor 2 of an electric motor is attached to the center of the rotating shaft 1. Reference numeral 3 denotes a stator (stator) of the electric motor, which generates a rotating magnetic field by the supplied current and applies a rotating force to the rotor 2. Reference numeral 4 denotes a bearing that rotatably supports the rotary shaft 1. A frame 5 holds the bearing 4 and the stator 3. Reference numeral 6 denotes an inverter, which supplies a current to a main winding 7 attached to the stator 3.

[0003]

In the AC motor constructed as described above, there was no problem caused by shaft vibration because the motor was conventionally driven at a constant speed at a relatively low rotation speed by the commercial frequency. However, with the spread and development of inverters, high-frequency driving has become possible and the rotation frequency has gradually increased.
Since the electric motor has a critical speed (natural frequency) of the rotating shaft 1 as shown in FIG. 16 due to its structure, it is difficult to operate at a speed exceeding the critical speed, and the high-speed rotation is practically limited. .

Accordingly, the present invention provides a rotating electric machine which can apply a damping force to the vibration of the rotating shaft at the critical speed of the rotating shaft, can operate the electric motor stably exceeding the critical speed, and can perform high-speed rotation by the inverter. It is an object to provide a vibration control device.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a stator having a main winding for generating a rotating magnetic field, a frame supporting the stator, and a frame. A rotating shaft rotatably supported,
Provided on the rotary shaft, the rotary electric machine having a rotor that generates rotational force by the rotating magnetic field generated in the main winding, _M the rotational frequency of the rotor omega, electrical rotating magnetic field by the main winding When the target frequency is ω, an attenuation control winding that generates a rotating magnetic field of ω _M + ω is provided separately from the main winding, and the angle from the magnetic pole position of the rotor to the direction of unbalance is α, The angle of the magnetic pole position of the rotating magnetic field generated by the attenuation control winding is β, the number of poles of the rotating electric machine is 2p poles (p is a natural number),
When the number of poles of the damping control winding is 2 (p + 1) poles, the slip of the rotor is s, and the relationship between the slip s and the direction of unbalance α is pα = pα ₀ + sωt, the damping control winding has The current flowing through the attenuation control winding is controlled so that the relationship between the generated rotating magnetic field and the direction of the unbalance is (p + 1) β = pα ₀ + π / 2 + (ω _M + ω) t, and the rotating shaft of the rotating electric machine is controlled. A damping force is applied to the vibration at the critical speed.

According to a second aspect of the present invention, the damping control winding of the first aspect is attached to a slot of a stator in which a main winding is accommodated. According to a third aspect of the present invention, the attenuation control winding of the first aspect is wound around a core back portion on the back side of the stator to reduce the size of the stator.

According to a fourth aspect of the present invention, the damping control winding according to the first aspect is attached to a gap between the stator and the rotor to facilitate assembly. According to a fifth aspect of the present invention, the stator of the first aspect is divided into a plurality of parts in the axial direction, and a damping control winding is attached to these stators. According to a sixth aspect of the present invention, the plurality of attenuation control windings of the fifth aspect are individually controlled.

According to a seventh aspect of the present invention, the stator of the first aspect is divided into three parts in the axial direction, and a damping control winding is attached to a central stator. According to an eighth aspect of the present invention, the slots of the plurality of stators of the fifth aspect are circumferentially shifted, and damping control windings are attached to these slots.

According to a ninth aspect of the present invention, the relationship between the rotating magnetic field generated by the damping control winding of the first aspect and the direction of imbalance is (p + 1) β = pα ₀ + (ω + ω _M ) t, The force generated from the line acts as a rigid force against shaft runout of the rotor.

According to a tenth aspect of the present invention, the relationship between the rotating magnetic field generated by the damping control winding of the first aspect and the direction of imbalance is defined as (p + 1) β = pα ₀ + (ω + ω _M ) t + γ, (0 <
γ <π / 2), and the force generated from the damping control winding acts as a damping force and a rigid force on shaft runout of the rotor.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an axial sectional view of a two-pole synchronous motor and a block diagram of a control system showing a configuration of an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a rotating shaft, and a rotor 2 of an electric motor is mounted at the center of the rotating shaft 1.
Reference numeral 3 denotes a stator of the electric motor, which generates a rotating magnetic field by the supplied current and applies a rotating force to the rotor 2. Reference numeral 4 denotes a bearing that rotatably supports the rotary shaft 1. A frame 5 holds the bearing 4 and the stator 3. Reference numeral 6 denotes an inverter, which supplies a current to a main winding 7 attached to the stator 3. Reference numeral 8 denotes a gear, which is provided with several tens or more teeth in one round, and is firmly attached to the shaft end of the rotating shaft 1. Reference numeral 9 denotes a target for detecting the rotational position, and a cut is provided at a position corresponding to the center of the magnetic pole of the rotor 2 in the circumferential direction. Reference numeral 10 denotes a rotational position detection sensor, which uses a displacement sensor such as an eddy current sensor. Reference numeral 11 denotes a rotation pulse sensor, and a rotation detection sensor 1
Similarly to the first embodiment, the rotating shaft 1 is comprised of an eddy current displacement sensor or the like, and is mounted to face the gear 8. When the rotating shaft 1 rotates, it outputs a pulse whose number is equal to the number of teeth of the gear 8. 1
Reference numeral 2 denotes a shaft runout sensor, which is composed of an eddy current displacement sensor or the like, like the rotation detection sensor 10, and is mounted at two locations in the axial direction across the rotor 2 of the electric motor so as to face the rotation shaft 1. The shake amount (lateral shake) is detected. Reference numeral 13 denotes an attenuation control winding, which is similarly attached to a slot of the stator 3 into which the main winding 7 is inserted, and generates a rotating magnetic field. Reference numeral 14 denotes a shaft runout calculator which calculates the shaft runout of the rotor 2 at the center in the axial direction based on an output signal of the shaft runout sensor 12 which is attached so as to sandwich the rotor 2 of the electric motor in the axial direction. Reference numeral 15 denotes a tracking filter, which extracts only a rotation frequency component from an output signal of the shaft shake calculator 14 by a pulse having a number of teeth times the number of rotations of the rotation pulse sensor 11. A control device 16 generates a control signal for an attenuation control winding from output signals of the rotational position sensor 10 and the tracking filter 15. 1
Reference numeral 7 denotes an amplification circuit that amplifies an output signal of the control device 16 and supplies the amplified signal to the attenuation control winding 13 as a current output.

Next, the operation of the above embodiment will be described. FIG. 2 is a conceptual diagram of a radial section of a central portion of the electric motor shown in FIG. 1, and it is assumed that a 2p pole machine is controlled by a 2 (p + 1) pole (p is a natural number) attenuation control winding. Also,
It is assumed that there is an imbalance in the direction of the angle α of the rotor 2 with reference to the line connecting the magnetic poles N and S, and the shaft runout occurs in this direction (X axis). In this figure, the magnetic flux density generated by the rotor 2 is Bm, the magnetic flux density of the stator 3 generated by the damping control winding 13 is Bc, the magnetic pole position (angle) of the rotating magnetic field generated by the damping control winding is β, and the damping is β. Control winding 1
If 3 is 2 (p + 1) poles,

[0013]

Bm (θ, t) = Bm · COS (pθ−pα) Bc (θ, t) = − Bc · COS {(P + 1) · θ ′ − (p + 1) · β} = − Bc · COS (P + 1) · θ + (p + 1) · ωt- (p + 1) · β｝ The magnetic attraction on the surface of the rotor 2 in the radial direction is per unit area.

[0014]

(Equation 2) When the damping force “−Fy” per unit length in the axial direction, which is generated with the radius of the rotor 2 as R, is obtained as follows.

[0015]

(Equation 3) Therefore, when the following relationship is established, the damping force is constant regardless of the rotation of the rotor 2.

[0016]

(Equation 4) Therefore, the frequency of the current supplied to the attenuation control winding 13 is (ω + ω _M ). Because ω = ω _M for a two-pole synchronous machine

[0017]

(Equation 5) Becomes Therefore, the output of the shaft runout sensor 12 attached to the rotor 2 in the axial direction is used to calculate the shaft runout calculator 14.
To obtain the axial runout of the rotor 2 at the central portion in the axial direction, and extract only the rotational frequency component by the tracking filter 15,
The phase difference (α) between this signal and the signal from the rotational position sensor 10 is determined, the frequency of the current supplied to the attenuation control winding 13 is (ω + ω _M ), and the phase difference from the magnetic pole position of the rotor 2 is pα + π / 2 (advance control), the magnetic attraction force acting on the rotor 2 becomes a damping force (damping) with respect to the shaft whirling, thereby suppressing shaft wobbling.

Further, by setting the phase difference to “pα”, the force generated by the damping control winding 13 acts as a rigid force (spring force) against the shaft run-out of the rotor 2 and “pα +
By setting γ ″, both the damping force and the rigidity force can be generated. However, γ is a value from 0 to π / 2.

FIG. 3 shows a modification of the vibration control device. In FIG. 3, reference numerals 1 to 17 are the same as those of the vibration control device of FIG. However, in FIG. 3, a synchronous speed detector 18 for detecting an electrical frequency from the output current of the inverter 6 is added, and the current flowing through the attenuation control winding 13 is controlled by the control device 16 so that the following relationship is satisfied.

[0020]

(Equation 6) Therefore, the vibration control according to this method can be performed in the induction motor. FIG. 4 shows a modified example of the vibration control device, in which the damping control winding 13 is wound around the core back portion of the rotating electric machine so as to wind the back side of the stator 3, thereby reducing the dimension of the stator 3 of the rotating electric machine. It is possible to make it smaller.

The vibration control device shown in FIG.
Is mounted in the space between the rotor 2 and the stator 3, and there is no need to wind the damping control winding 13 around the stator 3.
Thereby, assemblability is improved, and application to existing rotary electric machines is easy.

The vibration control device shown in FIG. 6 divides the stator 3 of the rotating electric machine into two parts in the axial direction, and divides the stator 3a, 3b
Attenuation control windings 13a, 1
3b, and the respective attenuation control windings 13a and 13b are controlled individually or synchronously. As a result, FIG.
Damping force can be effectively applied to the secondary mode of vibration shown in FIG.

The vibration control device shown in FIG. 7 divides the stator 3 of the rotating electric machine into three parts in the axial direction, and the attenuation control winding 13 is provided at the core back portion of the central stator 3c among the divided stators 3.
And control. Thereby, the axial dimension of the rotating electric machine can be reduced.

In the vibration control device shown in FIG. 8, the stator 3 of the rotating electric machine has a square iron core, and damping control windings 13a are provided at four corners.
To 13d. Thereby, the number of steps is reduced and the yield is improved.

FIG. 9 shows an embodiment of the vibration control device, and FIG. 10 is a sectional view taken along the line AA 'of FIG. As shown in FIG. 10, the slot shape is formed so as to be displaced in the circumferential direction on the outer diameter side of the slot of the stator 3 of the rotating electric machine, and the displaced direction is set so that the divided iron cores are opposite to each other. The attenuation control winding 13 is wound so that the attenuation control windings 13a and 13b do not interfere with each other at positions shifted in the circumferential direction. This makes it possible to further reduce the axial dimension.

FIG. 11 is a block diagram showing one embodiment of the vibration control device. The magnitude of the magnetic flux generated by the rotor 2 is detected by a magnetic sensor 19 provided on the stator 3 side, and the magnetic pole position calculator 21 rotates the magnetic flux. The magnetic pole position of the child 2 is calculated and controlled. Thus, there is no need to provide a disk such as the rotation position target 9 (FIG. 1) on the rotation shaft, and the structure of the rotation shaft 1 is simplified. A search coil or a Hall element for detecting the intensity of the magnetic flux may be used for the magnetic sensor 19.

FIG. 12 is a block diagram showing one embodiment of the vibration control device. The voltage of the main winding 7 is detected, and the magnetic pole position calculator 21 calculates and controls the magnetic pole position of the rotor 2. Accordingly, there is no need to provide a disk such as the rotation position target 9 or a rotation position detection sensor on the rotation axis, and the control device can be simplified.

FIG. 13 is a block diagram showing one embodiment of the vibration control device. The shaft vibration of the rotor 2 is arranged on the stator 3 side by a plurality of magnetic sensors 19 arranged symmetrically in the circumferential direction.
The magnitude of the main magnetic flux at each measurement position is measured, the unbalance of the main magnetic flux is calculated by the shaft runout calculator 20 from these values, and the shaft runout of the rotor 2 is obtained and controlled. Thereby, the space for mounting the displacement sensor 12 can be omitted, and the axial length of the rotating electric machine can be shortened. A search coil or a Hall element may be used for the magnetic sensor 19, respectively.

FIG. 14 is a block diagram showing a modification of the vibration control device shown in FIG. 1. A current is supplied from a power supply of an inverter 6 for supplying a current to a main winding 7 of a rotating electric machine to a damping control winding 13. The power supply is supplied to the shaft runout calculator 14, the tracking filter 15, the control device 16, and the current amplifier circuit 17, so that the power supply for the control system of the attenuation control winding 13 is not required, and the system is simplified. Can be achieved.

[0030]

According to the vibration control apparatus for a rotating electric machine of the present invention, a damping force or a restoring force can be applied to the rotor at the primary, secondary or higher critical speed of the rotating shaft. It is possible to operate at speeds exceeding these critical speeds, thereby realizing a rotating electric machine with higher rotation speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a vibration control device for a rotating electric machine according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a radial cross section of a central portion of the electric motor for explaining the principle of the vibration control device for a rotating electric machine according to the present invention.

FIG. 3 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 14 of the present invention.

FIG. 4 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 4 of the present invention.

FIG. 5 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 5 of the present invention.

FIG. 6 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 6 of the present invention.

FIG. 7 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 8 of the present invention.

FIG. 8 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 9 of the present invention.

FIG. 9 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 10 according to the present invention.

FIG. 10 is a sectional view taken along line AA ′ of FIG. 9;

FIG. 11 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 16 of the present invention.

FIG. 12 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 19 according to the present invention.

FIG. 13 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 20 according to the present invention.

FIG. 14 is a block diagram showing a configuration of a control device for a rotating electric machine according to claim 26 of the present invention.

FIG. 15 is an axial sectional view of a rotating electric machine according to a conventional technique.

FIG. 16 is a conceptual diagram of a vibration mode of a rotating shaft of a rotating electric machine according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotating shaft, 2 ... Rotor, 3 ... Stator, 4 ... Bearing, 5
... Frame 6 ... Inverter, 7 ... Main winding, 8 ... Gear, 9 ... Rotation position target 10 ... Rotation position sensor, 11 ... Rotation pulse sensor, 12
… Shaft runout sensor 13… damping control winding, 14… shaft runout calculator, 15… tracking filter 16… control device, 17… current amplifier circuit, 18… synchronous speed detector 19… magnetic sensor, 20… shaft runout calculator , 21 ... magnetic pole position calculator.

Continuation of the front page (72) Inventor Shunzo Watanabe 2-4 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Keihin Works

Claims (10)

[Claims] A stator having a main winding for generating a rotating magnetic field; a frame supporting the stator; a rotating shaft rotatably supported by the frame; and a rotating shaft provided on the rotating shaft. In a rotating electric machine having a rotor that generates a rotating force by a rotating magnetic field generated by a winding, when the rotating frequency of the rotor is ω _M and the electric frequency of the rotating magnetic field by the main winding is ω, ω An attenuation control winding for generating a rotating magnetic field of _M + ω is provided separately from the main winding, an angle from a magnetic pole position of the rotor to an unbalanced direction is α, a rotating magnetic field generated by the attenuation control winding. , The number of poles of the rotating electric machine is 2p poles (p is a natural number), the number of poles of the attenuation control winding is 2 (p + 1) poles, the slip of the rotor is s, and the slip s is unbalanced. When the relationship of the direction α is pα = pα ₀ + sωt Controlling the current flowing through the damping control winding such that the relationship between the rotating magnetic field generated by the damping control winding and the direction of imbalance is (p + 1) β = pα ₀ + π / 2 + (ω _M + ω) t A vibration control device for a rotating electric machine, comprising: 2. The vibration control device for a rotating electric machine according to claim 1, wherein said damping control winding is attached to a slot of said stator in which said main winding is accommodated. 3. The vibration control device for a rotating electric machine according to claim 1, wherein the damping control winding is wound around a core back portion on a back side of the stator. 4. The vibration control device for a rotating electric machine according to claim 1, wherein said damping control winding is mounted in a gap between said stator and said rotor. . 5. The vibration control apparatus for a rotating electric machine according to claim 1, wherein said stator is divided into a plurality of parts in an axial direction, and said damping control winding is attached to said stator. apparatus. 6. The vibration control device for a rotating electric machine according to claim 5, wherein the plurality of damping control windings are individually controlled. 7. The vibration control apparatus for a rotating electric machine according to claim 1, wherein said stator is divided into three in the axial direction, and said damping control winding is attached to a central stator. apparatus. 8. The vibration control apparatus for a rotating electric machine according to claim 5, wherein slots of said plurality of stators are shifted in a circumferential direction, and said damping control windings are attached to said slots. Control device. 9. The vibration control device for a rotating electric machine according to claim 1, wherein the relationship between the rotating magnetic field generated by the attenuation control winding and the direction of imbalance is (p + 1) β = pα ₀ + (ω
+ Ω _M ) t. 10. The vibration control device for a rotating electric machine according to claim 1, wherein a relationship between a rotating magnetic field generated by said damping control winding and an unbalance direction is (p + 1) β = pα ₀ +
(Ω + ω _M ) t + γ, wherein the range of γ is 0 <γ <π / 2.