JP6613118B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a vibration control technique for a rotating electrical machine, and more particularly to a vibration control technique using a hood damper.

  As a typical structure of a rotating electric machine such as an electric motor or a generator, a structure including a cylindrical stator fixedly supported and a rotor rotatably supported in the stator is widely known. . In a rotating electrical machine, resonance occurs when the electromagnetic force frequency acting between the stator and the rotor matches the natural frequency of the stator, and the stator vibrates and generates electromagnetic noise. is there.

  As a measure for suppressing such vibration of the rotating electrical machine, particularly vibration in the annular vibration mode, a technique of attaching a mass body for changing the natural frequency of the rotating electrical machine to the outside of the stator frame is known (patent) Document 1, Non-Patent Document 1).

  Moreover, the technique which suppresses the vibration of a motor with the damping member using a granular material is known (patent document 2).

JP 7-154940 A JP 2000-46103 A

Yoshitake Hiroshi, Nozaki Yuu, Kataharada Hiroyuki, Tagawa Natsuko, Yamazaki Go, Harada Kaoru, Vibration Stabilization of Motor Stator with Non-uniformity, Japan Society of Mechanical Engineers, Vol. 81, no. 821, 2015 (2015), 14-00386

  Patent Document 1 discloses a technique for attaching a mass body in order to change the natural frequency of a rotating electrical machine. There is no description. In addition, with the technique described in Patent Document 1 or Non-Patent Document 1, a vibration damping effect may not be sufficiently obtained. In particular, the technique described in Patent Document 1 or Non-Patent Document 1 can be used as a technique for avoiding resonance when operating at a constant rated rotational speed, but the rotational speed of an electric motor using an inverter, etc. Resonance cannot be avoided in a rotating electric machine that is used while being changed.

  Further, Patent Document 2 does not disclose anything about which position on the outer periphery of the motor is effective when the damping member using the powder particles is attached.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a large vibration damping effect even when the rotational speed of a rotating electrical machine changes using a hood damper. .

In order to achieve the above object, a rotating electrical machine according to the present invention includes a cylindrical fixed support member, a rotor that is rotatably supported in the fixed support member, and a predetermined position in the circumferential direction of the fixed support member. At least one non-uniform mass fixed to the non-uniform mass, spaced apart from the non-uniform mass in the circumferential direction of the fixed support member, and attached to the fixed support member. A rotating electric machine comprising: at least one hood damper that generates a resistance force in the radial direction according to a moving speed in the radial direction and does not generate a restoring force according to a displacement, wherein the at least one non-uniform mass body when taking a single angular coordinate in the direction of rotation of the rotor as the origin of the circumferential position of the heterogeneous mass of the angular coordinate position before notated Dodanpa is 15 to 35 degrees, 105 to 125 degrees, 195-215 degrees, 85-305 °, Ri near range only, the rotational speed of the rotor is configured to be variable, characterized by.

  According to the present invention, even if the rotation speed of the rotating electrical machine changes, a great vibration damping effect can be exhibited.

It is typical sectional drawing perpendicular | vertical to the rotating shaft of the rotary electric machine which concerns on embodiment of this invention. It is a figure which shows the example of distribution of the circumferential direction in sectional drawing perpendicular | vertical to the axis | shaft of a rotary electric machine of the electromagnetic force concerning the fixing support member of a rotary electric machine. A rotary electric machine according to an embodiment of the present invention, heterogeneous mass damper opening angle theta ₁ and the heterogeneous mass ratio mu _I is a graph showing the effect on the amplitude. 6 is a graph showing the influence of a non-uniform mass body / damper opening angle θ ₁ and a hood damper mass ratio μ _H on the amplitude in the rotating electrical machine according to the embodiment of the present invention. 5 is a graph showing the influence of a non-uniform mass body / damper opening angle θ ₁ and a hood damper damping ratio γ _H on the amplitude in the rotating electrical machine according to the embodiment of the present invention. In the rotary electric machine which concerns on embodiment of this invention, it is a graph which shows the example of the resonance curve which took the dimensionless frequency on the horizontal axis, and took the dimensionless amplitude on the vertical axis.

  Hereinafter, an embodiment of a rotating electrical machine according to the present invention will be described with reference to the drawings.

  First, an analysis method related to vibration suppression of an embodiment of a rotating electrical machine according to the present invention will be described.

  FIG. 1 is a schematic cross-sectional view perpendicular to the rotation axis of the rotating electrical machine according to the embodiment of the present invention. FIG. 2 is a diagram showing an example of the distribution in the circumferential direction in a cross-sectional view perpendicular to the axis of the rotating electrical machine, of the electromagnetic force applied to the fixed support member of the rotating electrical machine.

  In a hammering test, it is known that a mode having nodes in the axial direction cannot be obtained in a frequency range of several thousand Hz or less where electromagnetic vibration is a problem. Therefore, for the sake of simplicity, the stationary support member 10 including the stator of the rotating electrical machine and the outer stator frame is approximated by a uniform ring as shown in FIG. 1 that does not consider the axial distribution of displacement. I decided to. Here, the name of the “fixed support member” is “fixed” in the sense that the rotor 50 is supported without rotating, and when considering the vibration of the fixed support member 10, It is not fixed and vibrates.

  It is assumed that the fixed support member 10 is cylindrical and has a uniform thickness in the circumferential direction. Inside the fixed support member 10, a rotor 50 that rotates around an axis common to the axis of the fixed support member 10 is disposed. A gap 51 is formed between the fixed support member 10 and the rotor 50.

P non-uniform mass bodies 11 (mass: m _Ip ) are installed outside the fixed support member 10 at positions in the circumferential angle θ = α _p (p = 1,..., P). N food dampers (Houd Damper) 30 are installed at positions of the circumferential angle θ = θ _j (j = 1,..., N). In the example shown in FIG. 1, the number of non-uniform mass bodies 11 is P = 1, and the number of hood dampers 30 is N = 2. Further, it is assumed that the angular position coordinates are taken in the rotation direction of the rotor 50 indicated by the arrow A in FIG. Further, α ₁ = 0 degrees is set as the origin of the angular position coordinates of the non-uniform mass body 11.

The hood damper 30 generally refers to a vibration damping device including a resistance element 13 (damping coefficient: c _Hj ) and a damper mass body 14 (mass: m _Hj ) attached to the tip thereof. Here, since it is assumed that the fixed support member 10 performs an annular vibration, the damper mass body 14 is assumed to be movable at least in the radial direction. However, the structure of the hood damper is not limited to the structure shown in FIG. 1, and for example, a granular material or a viscous fluid that is movable in a closed container as disclosed in Patent Document 2 is used. It may be a thing.

  The radial displacement u of the fixed support member 10 is expressed by the following equation (1) when considering M vibration modes.

here,
θ: Coordinates in the circumferential direction (rad) (counterclockwise is positive)
i: integer representing a vibration mode in the circumferential direction a _i : displacement of a cos type mode i having a belly at θ = 0 b _i : displacement of a sin type mode i having a belly at θ = π / (2i)

  As a general external force acting on the electric motor, a force acting in the radial direction is an electromagnetic force distributed in the circumferential direction and rotating in the circumferential direction. Therefore, this is expressed by the following equation (2).

Where s: integer representing the mode of electromagnetic force Ω _s : angular frequency of electromagnetic force having mode s F _s : amplitude of electromagnetic force of mode s

The actual electromagnetic force contains many frequency components, only the component of _{F s cos (-Ω s t +} sθ) for simplicity assume that act. In addition, assuming that the non-uniform mass is not so large, it is treated as an inertial force, and a viscous damping force acts on the stator. When only the i-th mode is adopted and the case of i = s is handled, the equation of motion is It becomes like Formula (3)-Formula (5).

Where r: radius of the ring of the fixed support member E: longitudinal elastic modulus of the fixed support member A: cross-sectional area of the fixed support member (the product of the ring thickness H and the axial length L in the case of a rectangular cross section) )
I: moment of inertia of about primary vertical axis to the plane of the ring of the fixed support member (LH ^3/12 in the case of rectangular cross-section)
ρ: Density of fixed support member c _0i : Viscous damping coefficient of main system (i = 1,..., M)
x _j : Displacement of the hood damper installed at θ = θ _j (j = 1,..., N)
C _Hj : Viscous damping coefficient of the hood damper installed at θ = θ _j (C _Hj = 2γ _Hj m _Hj ω _0i )
ω _0i : Natural angular frequency of i-th mode m _Hj : Mass of hood damper installed at θ = θ _j m _Ip : Mass of non-uniform mass installed at θ = α _p P: Number of non-uniform mass N : Number of food dampers

Here, the mode of i = 2 is taken as an example, and vibration suppression by a non-uniform mass body and a hood damper is considered. For example, in a single hood damper, the steady solutions of the equations (3) to (5) are set as the following equations (6) to (8).
a ₂ = A ₁ cosΩ ₂ t + B ₁ sinΩ ₂ t (6)
b ₂ = A ₂ cosΩ ₂ t + B ₂ sinΩ ₂ t (7)
x ₁ = A ₃ cosΩ ₂ t + B ₃ sinΩ ₂ t (8)

When i is 0, the vibration of the circular ring becomes larger or smaller as it is. When i is 1, the shape and size of the circular ring remains unchanged, and the vibration is alternately displaced to one circumferential position and the opposite side. In formulas (3) and (4), these are excluded.

  When i is 2, the radial displacement is at an intermediate position between the belly where the amplitude is maximum and the belly and the belly every 90 degrees in the circumferential direction, similar to the distribution of force shown in FIG. A node having the smallest amplitude is formed. When i is 3 or more, belly and nodes are alternately formed at equal intervals in the circumferential direction.

  In a vibration phenomenon in an actual rotating electrical machine, the case where i = s is 2 is usually most important. Therefore, in the following, the case of i = s = 2 will be studied. Therefore, each phenomenon at each angular position in the circumferential direction described below is the same at 180 degrees from the angle, and the displacement, speed, acceleration, etc. at each time are the same, and 90 degrees and 270 degrees are shifted from the angle. In terms of position, this means that a phenomenon occurs in which the absolute values of displacement, speed, acceleration, etc. at each time are the same and the signs are reversed.

[Numerical analysis results]
Here, there is only one non-uniform mass 11 at the angular coordinate position α ₁ = 0 ° (P = 1), and there is only one hood damper 30 at the angular coordinate position θ ₁ (N = 1). ) The results of numerical analysis of the state of annular vibration of the fixed support member 10 in this case will be described with reference to FIGS. Here, θ ₁ is an opening angle between the non-uniform mass body 11 and the hood damper 30, and is therefore referred to as a non-uniform mass body / damper opening angle in the following description.

The mode mass of i = 2 of the fixed support member 10 is m, and the mass ratio m _I1 / m of the non-uniform mass 11 is μ _I. The i = 2 mode mass m of the fixed support member 10 is represented by m = (5/4) πrρA. Further, the hood damper mass ratio m _H1 / m of the hood damper 30 is μ _H , and the hood damper damping ratio C _H1 / (2 m _H1 ω ₀₂ ) is γ _H. However, ω ₀₂ ² = 36EI / (5ρAr ⁴ ).

  For comparison, the calculation results when there is no non-uniform mass body 11 and no hood damper 30 are also displayed in FIGS.

  The embodiment of the present invention satisfies the condition that the amplitude obtained by the analysis is as small as possible.

In Figures 3-6, the vertical axis A ^2, as shown by the following equation (9), an average of the square of the radial displacement u of the formula (1) in space and time (F ₂ π / k ₀₂ ) This is defined as being dimensionless by dividing by ² .

However, k ₀₂ = 9EIπ / r ³ and T = 2π / Ω ₂ .

Further, the horizontal axis ν of the resonance curve shown in FIG. 6 is ν = Ω ₂ / ω ₀₂ , and the angular frequency of the electromagnetic force is made non-dimensional with the natural angular frequency of the secondary mode. Accordingly, ν = 1 on the horizontal axis in FIG. 6 is the dimensionless natural angular frequency of the secondary mode of the main system, that is, the resonance point. Furthermore, the maximum dimensionless amplitude value of the resonance curve obtained from the calculation using the set parameter values is adopted as the dimensionless amplitude value on the vertical axis in FIGS.

FIG. 3 is a graph showing the influence of the non-uniform mass body / damper opening angle θ ₁ and the non-uniform mass ratio μ _I on the amplitude in the rotating electrical machine according to the embodiment of the present invention. Here, the hood damper mass ratio mu _H and 0.1, the hood damper damping ratio gamma _H was 0.5. Changing the heterogeneous mass ratio mu _I to three different 0.05,0.1,0.15, when changing to various values in the range heterogeneous mass damper opening angle theta ₁ between 0 and 90 degrees effect of the dimensionless amplitude a ² is shown.

From the analysis results of FIG. 3, regardless of the value of the non-uniform mass ratio mu _I, heterogeneous mass damper opening angle theta ₁ it can be seen that the minimum value amplitude in the range of 15 to 35 degrees.

FIG. 4 is a graph showing the influence of the non-uniform mass body / damper opening angle θ ₁ and the hood damper mass ratio μ _H on the amplitude in the rotating electrical machine according to the embodiment of the present invention. Here, the heterogeneous mass ratio mu _I and 0.1, the hood damper damping ratio gamma _H was 0.5. The hood damper mass ratio μ _H is changed to four values of 0.05, 0.075, 0.1, and 0.15, and the non-uniform mass / damper opening angle θ ₁ is set to various values within a range of 0 to 90 degrees. effect of the dimensionless amplitude a ² when changing are shown.

From the analysis results of FIG. 4, irrespective of the value of the hood damper mass ratio mu _H, heterogeneous mass damper opening angle theta ₁ it can be seen that the minimum value amplitude in the range of 15 to 35 degrees.

FIG. 5 is a graph showing the influence of the non-uniform mass body / damper opening angle θ ₁ and the hood damper damping ratio γ _H on the amplitude in the rotating electrical machine according to the embodiment of the present invention. Here, the heterogeneous mass ratio mu _I and 0.1, and the hood damper mass ratio mu _H to 0.1. The hood damper damping ratio γ _H is changed to four values of 0.1, 0.2, 0.3, and 0.5, and the non-uniform mass / damper opening angle θ ₁ is set to various values in the range of 0 to 90 degrees. effect of the dimensionless amplitude a ² when changing are shown.

From the analysis result of FIG. 5, it can be seen that the amplitude has a minimum value in the range of the non-uniform mass / damper opening angle θ ₁ of 15 to 35 degrees regardless of the value of the hood damper damping ratio γ _H.

FIG. 6 is a graph showing an example of a resonance curve in which the dimensionless frequency is plotted on the horizontal axis and the dimensionless amplitude is plotted on the vertical axis in the rotating electrical machine according to the embodiment of the present invention. The analysis conditions in FIG. 6 are selected from the range in which the amplitude is particularly small according to the analysis results in FIGS. That is, the heterogeneous mass ratio mu _I and 0.1, the hood damper mass ratio mu _H and 0.1, the hood damper damping ratio gamma _H was 0.5. Further, the non-uniform mass body / damper opening angle θ ₁ was set to 28 degrees.

  According to the analysis results shown in FIG. 6, the dimensionless frequency taking the peak of the sine mode and the cosine mode is shifted, and the maximum dimensionless amplitude as the sum of the sine mode and the cosine mode is not uniform. Compared to the case where neither the mass body 11 nor the hood damper 30 is provided, the mass is greatly reduced.

As described above, in the rotating electric machine including one non-uniform mass body 11 and one hood damper 30, the non-uniform mass body / damper opening angle θ _{1 is set} to 15 to 35 degrees, thereby causing non-uniformity. Regardless of the values of the mass ratio μ _I , the hood damper mass ratio μ _H , and the hood damper damping ratio γ _H , the maximum amplitude can be kept low.

  Further, in this case, the frequency of the resonance point is not simply shifted, but the maximum amplitude is reduced. Therefore, this is particularly effective for a rotating electrical machine that performs variable speed operation such as an inverter-driven electric motor.

  As described above, the case where i = s = 2 is considered here. That is, each phenomenon at each angular position in the circumferential direction is a position shifted by 180 degrees from the angle, and the displacement, speed, acceleration, etc. at each time are the same, and a position shifted by 90 degrees or 270 degrees from the angle Then, a phenomenon occurs in which the absolute values of displacement, speed, acceleration, etc. at each time are the same and the signs are reversed.

Therefore, for example, in the above description, one non-uniform mass body 11 that is arranged at the position of the angular coordinate position α ₁ = 0 degree is set to any position of 0 degree, 90 degrees, 180 degrees, and 270 degrees. Even if the arrangement is changed or divided, the same vibration damping effect can be obtained. Further, the angular coordinate position theta ₁ of the hood damper 30, 15 to 35 degrees, 105 to 125 degrees, 195-215 degrees, be placed in a position of any one of a range of 285 to 305 degrees, among them The same vibration damping effect can be obtained even when arranged at positions in a plurality of ranges.

  When the angle coordinate position of one non-uniform mass body is set to 0 degree, the angle coordinate positions of the other non-uniform mass bodies divided above are different by about 10 degrees before and after 90 degrees, 180 degrees, and 270 degrees. However, the same vibration control effect is expected. The width of the angular coordinate position is an analogy from the allowable range width of the angular coordinate position of the hood damper 30. Therefore, it is preferable that the angular coordinate positions of the other divided non-uniform mass bodies are in the range of 80 to 100 degrees, 170 to 190 degrees, and 260 to 280 degrees.

In numerical analysis explained above, a range weight ratio mu _I of heterogeneous mass body 11, it is clear that there is a damping effect larger, the accuracy of the results obtained in numerical calculation is guaranteed to some extent high accuracy as the mass ratio mu _I of heterogeneous mass 11 was 0.05 to 0.15. It goes without saying that even if the mass ratio mu _I larger than 0.15 damping effect is obtained.

For even mass ratio mu _H of the hood damper 30, it is clear that the damping effect increases these larger is large.

Regarding the damping ratio γ _H of the hood damper, it is known that γ _H = 1 / √ [2 (2 + μ _H ) (1 + μ _H )] is optimal in a normal vibration system. For example, when the mass ratio μ _H = 0.05 of the hood damper, the damping ratio γ _H = 0.482 is optimal, and when the mass ratio μ _H = 0.025, the damping ratio γ _H = 0.491 is optimal. It is. Smaller mass ratio mu _H, when the attenuation ratio gamma _H of about 0.5 is optimal. Therefore, as a condition for the above numerical analysis, a case where γ _H = 0.5 is used as a standard.

  In the above description, the “non-uniform mass body” is not necessarily attached specifically for vibration suppression, and includes a terminal box and cooling fins attached to the outside of the stator frame of the rotating electrical machine.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

10: Fixed support member (stator and stator frame)
11 ... Non-uniform mass 13 ... Resistance element 14 ... Damper mass 30 ... Hood damper 50 ... Rotor 51 ... Gap

Claims (2)

A cylindrical fixed support member;
A rotor rotatably supported in the fixed support member;
At least one non-uniform mass fixed to a predetermined position in the circumferential direction of the fixed support member;
The fixed support member is spaced apart from the non-uniform mass body in the circumferential direction, and is attached to the fixed support member. The resistance force in the radial direction is increased according to the moving speed of the fixed support member in the radial direction. At least one hood damper that does not produce a restoring force in response to the displacement;
A rotating electric machine having
When taking at least one of a single angular coordinate in the direction of rotation of the rotor as the origin of the circumferential position of the heterogeneous mass of inhomogeneous mass, the angular coordinate position before notated Dodanpa, 15 35 degrees, 105 to 125 degrees, 195-215 degrees, Ri near-only range of 285 to 305 degrees,,
The rotational speed of the rotor is configured to be variable ;
Rotating electric machine.   There are a plurality of the non-uniform mass bodies, and the angular coordinate position of the plurality of non-uniform mass bodies is 0 degree, and at least one of the ranges of 80 to 100 degrees, 170 to 190 degrees, and 260 to 280 degrees. The rotating electrical machine according to claim 1, wherein

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