JPH059927B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to stationary induction electric appliances such as transformers and reactors, and particularly to one that reduces noise generated due to vibration.

In general, stationary induction appliances generate vibrations due to magnetostriction occurring in the components of the magnetic circuit and electromagnetic attractive force due to leakage magnetic flux. This vibration is transmitted to externally facing structures, such as containers, causing noise. In order to reduce this noise, various measures have been taken in the past, such as reducing the magnetic flux density, installing a special circuit to cancel leakage magnetic flux, or surrounding the entire stationary induction device with a soundproof wall. It's here. However, with these countermeasures, the static induction appliance becomes larger and weighs more, the configuration of the static induction appliance becomes more complicated, or sufficient soundproofing effects cannot be obtained considering the increased installation area. There were drawbacks such as:

Therefore, recently, a method of canceling the vibration by applying opposite-phase vibration to a vibrating stationary induction appliance container has been studied. In this method, a vibration sensor and a vibrator are attached to the container of a stationary induction electric appliance, and the vibrator applies vibrations that are almost in the opposite phase to the vibrations detected by the vibration sensor to the container, thereby suppressing the vibration of the container. It is. However, with this method, since the inside of the container is filled with insulating oil, a large excitation force is required to vibrate the walls of the container, and a large vibrator is required to obtain sufficient soundproofing effects. As a result of the study, it was found that there was a need to increase the number of vibration exciters. Furthermore, since the vibration sensor and the vibrator are attached to the outside of the container, their resistance to wind and rain is also a problem.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology, to provide a low-noise stationary induction electric device that can efficiently reduce vibration using a small number of vibrators, and that can sufficiently protect the vibration sensor and the vibrator. It is on offer.

To achieve this object, the present invention provides a stationary induction electric appliance in which a core and a winding are housed in a container and a soundproof wall is provided to cover at least the peripheral side of the stationary induction electric appliance main body which is filled with insulating oil. A vibration sensor that detects vibrations of the soundproof wall and a vibrator that vibrates the soundproof wall are provided inside the soundproof wall, and an output of the vibrator is adjusted in accordance with an input from the vibration sensor. The present invention is characterized in that a control device is provided to control vibrations of the soundproof wall to be suppressed, and the vibrator is further attached to a reinforcing stay of the soundproof wall.

FIG. 1 shows an example of a conventional transformer with soundproof walls.

The core and windings are housed in a container 2 of a transformer body 1, which is filled with insulating oil. This transformer body 1 is surrounded by a soundproof wall 3. This soundproof wall 3
Generally, it is composed of a side plate 4 made of steel plate with a thickness of several mm to more than ten mm, and a reinforcing stay 5 made of H-shaped steel or L-shaped steel. Note that the soundproof wall 3 is usually constructed on a foundation different from the transformer main body 1 in order to insulate the vibration system.

In such a transformer with a soundproof wall, the vibration of the iron core is transmitted to the container 2 via the insulating oil, and the container 2 vibrates and radiates noise into the space 6 between the transformer body 1 and the soundproof wall 3. The vibrations are further transmitted to the soundproof wall 3 using the air in the space 6 as a medium, and the soundproof wall 3 vibrates and radiates noise to the outside.

Figures 2 and 3 show the vibration modes of the soundproof wall in a transformer with soundproof walls as described above.
1/2 of the circumferential side of the soundproof wall 3 in Figure 1, respectively.
is shown as viewed from the direction of arrow X.

Figure 2 shows an example of the natural vibration mode when the side plate of the soundproof wall and the reinforcement stay vibrate together, and Figure 3 shows the natural vibration mode when the vibration of the reinforcement stay is small and the vibration of the side plate is large. This is an example.

Even in such a transformer with a soundproof wall, since the soundproof wall itself vibrates due to sound pressure from inside, it is inevitable that a certain amount of noise will be radiated to the outside. However, what should be noted here is that there is air on both sides of the soundproof wall. Since there is air on both sides of the soundproof wall, it is much easier to excite than a container filled with oil.
By attaching a vibrator to the soundproof wall to suppress the vibration, noise can be efficiently reduced.

Furthermore, if the vibration exciter is installed at the reinforcement stay, the excitation force will be applied linearly to the soundproof wall due to the rigidity of the reinforcement stay, making it possible to reduce the number of vibration exciters installed. can.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

4 and 8 show an embodiment of the present invention, and in these figures, 1 is the transformer main body, 2
3 is the container, and 3 is a soundproof wall, which is composed of a side plate 4 and a reinforcing stay 5 made of H-beam steel. 7 is a bushing pocket that penetrates the soundproof wall 3, 8 is a bushing, and 9 is an oil pipe.

In this embodiment, in such a transformer with a soundproof wall, a vibration sensor 10 for detecting the vibration of the soundproof wall 3 and a vibrator 11 for vibrating the soundproof wall 3 are installed inside the soundproof wall 3. At the same time, the control device 12 of the vibration exciter 11 is installed in the space 6 between the transformer body 1 and the soundproof wall 3, and the installation position of the vibration exciter 11 is aligned with the reinforcement stay 5 as shown in FIG. This is what I did. In addition, illustration of the reinforcing stay 5 is omitted in FIG. 4.

The vibration sensor 10 is, for example, an acceleration sensor type using a piezo element, and outputs an electric signal corresponding to the frequency, amplitude, and phase of the vibration of the soundproof wall 3. The control device 12 inputs the output of the vibration sensor 10, creates a signal having a phase almost opposite to that of the vibration, and amplifies the power of the signal to transmit the signal to the vibration exciter 11.
Excite. The vibrator 11 is, for example, in the form of an inertial force vibrator, and suppresses the vibration of the soundproof wall 3 by vibrating the soundproof wall 3 in substantially the opposite phase to the vibration of the soundproof wall 3 .

Next, an example of the operation for suppressing vibration will be explained with reference to FIG. 5.

Vibration of the soundproof wall 3 is detected by a vibration sensor 10. The analog detection time signal detected by the vibration sensor 10 is converted into a digital detection time signal by an analog-to-digital converter 13 in the control device 12, and then converted into a digital detection frequency signal by a Fourier transformer 14. Since this digital detection frequency signal represents the amplitude and phase of each frequency component of the vibration generated in the soundproof wall 3, the arithmetic unit 15 calculates the amplitude for each frequency so that the amplitude of these frequency components becomes small. and the phase amount, and send this to the Fourier inverse transformer 16 as a digital vibration reduction frequency signal. The digital vibration reduction frequency signal is converted into a digital vibration reduction time signal by the Fourier inverse transformer 16, further converted into an analog vibration reduction time signal by the digital-to-analog converter 17, and then amplified by the power amplifier 18. and is sent to the vibrator 11 to energize it. The vibrator 11 generates vibrations that reduce the amplitude of each frequency component of the vibrations generated in the soundproof wall 3 by being energized by the amplified analog vibration reduction time signal, and applies the vibrations to the soundproof wall 3 to reduce the soundproofing. Reduce vibration of wall 3.
The arithmetic device 15 changes the amplitude and phase of the digital vibration reduction frequency signal so that the vibration of the soundproof wall 3 is always minimized in accordance with the vibrations generated in the soundproof wall 3, that is, changes in the digital detection frequency signal. . Further, the sampling of the analog-to-digital converter 13 and the digital-to-analog converter 17 is controlled by a synchronizing signal generated by a synchronizing signal generating device 19, and this synchronizing signal generating device 19
Since the frequency of vibration of the soundproof wall 3 and an integral multiple of the power frequency of the transformer body 1 match, a synchronization signal of an integral multiple of the power frequency is generated using the power frequency of the transformer body 1 as an input. Note that the Fourier transformer 14, the arithmetic unit 15, and the Fourier inverse transformer 1
7 is composed of, for example, a microcomputer.

As described above, according to this embodiment, the vibration sensor and the vibration exciter are attached to the soundproof wall, which has air on both sides and is easy to vibrate. The excitation force required for this purpose can be reduced, and noise can be efficiently reduced using a small vibrator or a small number of vibrators. In addition, the vibration sensor and exciter are installed inside the soundproof wall, and the control device is installed in the space between the transformer body and the soundproof wall, so both are completely protected against wind and rain and can be used for a long time. This ensures stable operation. Furthermore, since the vibrator 11 is attached to the reinforcing stay 5, the excitation force is linearly applied to the soundproof wall 3 due to the rigidity of the reinforcing stay 5. The number of vibrators to be installed can be reduced, and control of the vibrator by the control device can also be simplified. That is,
The vibrator 11 is generally attached to the side plate 4 as shown in FIG.
However, in this case, the excitation force is only applied point-wise, so it would be necessary to install a large number of vibrators. When attached to the stay 5 and applying the excitation force linearly, the number of installed vibrators 11 can be significantly reduced. Although there is some sound leakage from the bushings and oil pipes in this embodiment, the main cause of the noise radiated to the outside is the vibration of the soundproof wall, so if this can be suppressed, the noise will be significantly reduced.

FIG. 6 shows another embodiment of the invention. In this embodiment, an eave-shaped soundproof wall 3a is provided around the transformer main body 1.
A vibration sensor 10 and a vibrator 11 are installed inside the eave-shaped soundproof wall 3a, and a control device 12 is installed in the space between the transformer body 1 and the soundproof wall 3a.
This is what was installed. Note that the illustration of the reinforcing stay 5 is also omitted in FIG. 6. Such a canopy-shaped soundproof wall 3a is suitable when the vibration of the ceiling surface of the container 2 of the transformer main body 1 is small. The operation for preventing soundproofing is the same as in the previous embodiment. According to this embodiment, there is an advantage that the number of vibration sensors and vibration exciters can be reduced because the soundproof wall does not have a ceiling portion.

The way to attach the vibrator 11 is related to the structure of the soundproof wall and the vibration mode, but in the case where the vibrator is attached to the reinforcing stay as shown above, the side plate and the reinforcing stay are integrated as shown in Figure 2. This is particularly effective in the case of a vibration mode that vibrates in a circular motion, and it is also effective to install the vibrator at the antinode of the vibration.

In each of the embodiments described above, the case where the stationary induction electric appliance main body is a transformer has been described, but the same applies even if this is a reactor or the like.

Further, in the above embodiment, the control device is installed in the space between the transformer main body and the soundproof wall, but this control device can also be installed outside the soundproof wall for convenience of adjustment.

Kirani: In the above embodiment, the vibration sensor and the vibration exciter were installed one-to-one at the same location, so it was explained that the vibration exciter applied an excitation force in the opposite phase to the vibration detected by the vibration sensor. If the sensor and vibration exciter are installed far apart, or if one vibration sensor is controlled by input from vibration sensors installed at multiple locations, the output of the vibration exciter may not necessarily be detected by the vibration sensor. It is not necessarily the case that the vibration will be in the opposite phase to the vibration that occurred. In short, the vibration exciter should be controlled so that the vibration detected by the vibration sensor is reduced.

As explained above, in the present invention, a soundproof wall is provided so as to cover at least the peripheral side of the stationary induction electric appliance body, and a vibration sensor and a vibration exciter are attached to this soundproof wall. Since a soundproof wall has air on both sides and is much easier to vibrate than a container filled with insulating oil, the present invention can efficiently create a soundproof wall with a small vibrator or a small number of vibrators. It is possible to suppress vibrations and reduce noise. Furthermore, since the vibration sensor and the vibrator are installed inside the soundproof machine, they are completely protected against wind and rain, and stable operation can be ensured over a long period of time. Furthermore, since the vibration exciter is attached to the reinforcing stay, the excitation force is applied linearly to the soundproof wall due to the rigidity of the reinforcement stay, so the number of vibration exciters installed is small. This also simplifies the control of the vibration exciter by the control device.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing an example of a conventional transformer with soundproof walls, FIGS. 2 and 3 are explanatory diagrams showing the vibration modes of the soundproof walls, and FIG. 4 is an embodiment of the present invention. 5th cross-sectional view showing the low noise transformer according to
The figure is a block diagram showing the control system in the low-noise transformer of Fig. 4, Fig. 6 is a sectional view showing a low-noise transformer according to another embodiment of the present invention, and Figs. 7 and 8 are respectively soundproofing. It is a perspective view showing how to attach a vibrator to a wall. 1...Transformer body, 2...Container, 3, 3a...
Soundproof wall, 4... Side plate, 5... Reinforcement stay, 6...
Space, 10... Vibration sensor, 11... Vibrator, 1
2...control device.

Claims (1)

[Claims] 1 A stationary induction electric appliance body containing an iron core and a winding wire in a container and filled with insulating oil, and a soundproof wall consisting of a side plate and a reinforcing stay provided to cover at least the circumferential side of the stationary induction electric appliance body. A vibration sensor that detects vibrations of the soundproof wall and a vibrator that vibrates the soundproof wall are provided inside the soundproof wall, and the vibration sensor detects the vibration of the soundproof wall, and a control device that controls the output of the machine so that vibrations of the soundproof wall are suppressed;
Furthermore, a low-noise stationary induction electric appliance characterized in that the vibrator is attached to the reinforcing stay.