CA1181013A - Noise-reduction device for stationary induction apparatus - Google Patents
Noise-reduction device for stationary induction apparatusInfo
- Publication number
- CA1181013A CA1181013A CA000416574A CA416574A CA1181013A CA 1181013 A CA1181013 A CA 1181013A CA 000416574 A CA000416574 A CA 000416574A CA 416574 A CA416574 A CA 416574A CA 1181013 A CA1181013 A CA 1181013A
- Authority
- CA
- Canada
- Prior art keywords
- sound insulation
- insulation panels
- tank
- induction apparatus
- noise
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/33—Arrangements for noise damping
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/10—Applications
- G10K2210/125—Transformers
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/10—Applications
- G10K2210/129—Vibration, e.g. instead of, or in addition to, acoustic noise
- G10K2210/1291—Anti-Vibration-Control, e.g. reducing vibrations in panels or beams
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/301—Computational
- G10K2210/3011—Single acoustic input
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/301—Computational
- G10K2210/3013—Analogue, i.e. using analogue computers or circuits
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/321—Physical
- G10K2210/3216—Cancellation means disposed in the vicinity of the source
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/50—Miscellaneous
- G10K2210/509—Hybrid, i.e. combining different technologies, e.g. passive and active
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Regulation Of General Use Transformers (AREA)
- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A noise-reduction device for a stationary induction apparatus is disclosed in which sound insulation panels for reducing the noises radiated from the side walls of a tank are mounted on the reinforcing channel protruded outside of the tank of the induction apparatus.
Vibration sensors detect the vibrations transmitted from the tank to the sound insulation panels through the reinforcing channels. Vibrators apply vibrations of opposite phase to the vibrations detected by the vibration sensors. The vibration sensors and vibrators make up vibration cancelling devices.
A noise-reduction device for a stationary induction apparatus is disclosed in which sound insulation panels for reducing the noises radiated from the side walls of a tank are mounted on the reinforcing channel protruded outside of the tank of the induction apparatus.
Vibration sensors detect the vibrations transmitted from the tank to the sound insulation panels through the reinforcing channels. Vibrators apply vibrations of opposite phase to the vibrations detected by the vibration sensors. The vibration sensors and vibrators make up vibration cancelling devices.
Description
1 The present invention relates to a noise-reduction device for reducing the noises generated from the tank of a stationary induction apparatus such as a transformer or reactor.
With the recent expansion of ur~an areas and the resultant construction of residential housings near to a power station or su~station, the demand has increas-ingly be raised for reducing the noises generated from stationary induction apparatuses such as the transformer.
The noises of the stationary induction apparatuses are caused by the magnetostriction of the core which in turn causes electromagnetic vi~rations to be transmitted to the tank through such a medium as oil and are radiated into the atmosphere as a noise from the tankO Various measures have so far been taken to prevent such noises.
In one method, the transformer is installed in a sound-proof ~uilding of concrete or steel plates to shut off or absorb the noises. This method has various disadvantage including an increased installation space
With the recent expansion of ur~an areas and the resultant construction of residential housings near to a power station or su~station, the demand has increas-ingly be raised for reducing the noises generated from stationary induction apparatuses such as the transformer.
The noises of the stationary induction apparatuses are caused by the magnetostriction of the core which in turn causes electromagnetic vi~rations to be transmitted to the tank through such a medium as oil and are radiated into the atmosphere as a noise from the tankO Various measures have so far been taken to prevent such noises.
In one method, the transformer is installed in a sound-proof ~uilding of concrete or steel plates to shut off or absorb the noises. This method has various disadvantage including an increased installation space
2~ of the stationary induction apparatus, an increased production cost and a lengthened construction period.
A simple noise-reduction method for stationary induction apparatuses overcoming the above-mentioned dis-advantages in which the noises are cancelled ~y a sound of the phase oposite to the noises of the stationary induction apparatus involved has been suggested by Japanese Patent Publication No. 417/58 of General Electric Company published January 28, 1958. This method, however~ is not yet practically used in view of the fact that the noises generated by an induction apparatus, which is complicated in construction, include a multiplicity of frequency components, thereby making it necessary to provide separate loud speakers for different frequency components, with the result that an increased number of loud speakers are lQ required on the one hand and the adjustment of the frequency and sound volume is complicated on the other hand A method to improve this disadvantage is disclosed in European patent application No. 0043565 by Yasuro Hori et al published January 13, 1982 and entitled "Vibration/
Noise Reduction Device for Electrical Apparatus", in which the vibrations generated in an induction apparatus are detected and the frequen~y components of the vibrations are determined by Fourier transformation, so that additional vibrations are applied in a manner to cancel the vibrations of the respective frequency components by vibrators mounted on the induction apparatus. This system also requires a number of vibrators as in the case of the above-mentioned Japanese Patent Publication. Further, vibrators of larger power is required to cancel the vibrations of the ~,~
1 induction apparatus.
U.S. Patent co-pending Application Serial No.
406,564 filed August 9, 1982 by Syuya Hagiwara and Yasuro Hori and entitled "Method and Apparatus for Reducing Vibrations of Stationary Induction Apparatus" also discloses a system similar to the one disclosed in U.S.
Patent Application Serial No. 27~,814, in which the phase and amplitude of the vibrations caused ~y the vibrators are adjusted advantageously. The a~ove-mentiQned problems, ho~ever, are not solved even by this suggested method.
Other conventional systems include U.S. Patent Application Serial No. 217,772 filed ~ecember 18, 1980 and entitled "Static Induction Apparatus" in which a sound-insulating plate is mounted on the framework such as areinforcing channel on thR outside surface of the tank through an elastic memher there~y to reduce the noises produced from the tank, and Japanese Patent Puhlication No. 873a6/81 entitled l'Static Induction Apparatus" in 2~ which a similar sound-insulation panel is provided with a weighty material there~y to reduce the vibrations trans mitted from the tank through the reinforcing channel to the sound insulation panel. The former method has the disadvanta~e that although the noises (primary noises~
radiated by way of the outer wall of the tank through the oil from the winding and core are capa~le of ~eing reduced, it is impossi~le to reduce the noises (secondary noises~ caused by th~ vibrations of the sound lnsulation 1 panels in which the vibrations are transmitted from -the outer wall of the tank through the reinforcing channel.
In the latter method Gomprising a sound insulation panel and a weighty material combined which is intended to reduce the secondarv noises, on the other hand, the noise reduction level is limited by the physical limita-tions of the strength or dimensions of the elastic member for carrying the sound insulation panels or the size of the weighty material.
An object of the present invention is to provide a noise-reduction device for stationary induction appara-tuses, which obviates the disadvantages of the prior art de-vices and effectively reduces the noises caused by the tank.
- In order to achieve this object, aGcording to the present invention, there is provided a noise-reduction device, in which the primary noises radiated from the outer wall of the tank are pxevented by sound insulation panels mounted on the outer wall of the tank through a framework such as reinforcing channels, and vibration cancelling means including vibration sensors and vibrators are mounted on the sound insulation panels, so that the controlling force of a phase opposite -to the vibratlon transmitted from the tank through the reinforcing channel to the sound insulation panels causing the secondary noises is applied thereto, thus maklng it possible to cancel the vibrations by a smaller number of vibrators with a smaller controlling force than when the controlling force is applied directly to the tank.
,3 1 The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:
Fig. 1 is a partly cut-away side view showing the general construction of a noise reduction device for a transformer according to an embodiment of the present invention;
Fig. 2 is a partly cut-away perspective view of a-noise reduction device on which sound insulation panels and reinforcing channels are mounted;
Fig. 3 is a enlarged sectional view at lef.t hand portion of Fig. 1, Fig. 4 i5 a perspective view of the essential parts showing a configuration of a noise reduction device for a transformer according to another embodiment of the present invention~ and Fig. 5 is a central longitudinal sectional view 2~ taken parallel to t~e tank plan view with the noise reduction device of Fig. 4 mounted on the tank through the reinforcing frames, An embodiment of the. present invention will he described below with reference to Figs. 1, 2 and 3.
In these figures, reference numeral 1 designates a transformer tank containing a winding and core 18 and filled with an insulating oil 1~. At least a pair of reinforcing channels 3 of U-sh.aped steel surrounding the 1 tank 1 are securely welded to th.e side walls 2 of the tank 1 thereby to reinforce the tank 1. A plurarity of sound-insulation panels 4 surrounding -the whole periphery of the tank including the main vihration section providing a noise source are mounted in such a manner as to close the part of the side walls 2 between the reinforcing channels 3. At the part of the side walls 2 which is covered by the sound insulation panels 4, as shown by the arrow A in Fig. 3, the primary noises radiated by the vibrations generated from the winding and core 1~ and transmitted to the side walls 2 through the insulating oil 1~ are blocked hy the sound insulation panels 4.
The sound insulation panels 4 is preferably made of highly damped plate with resin sandwiched between a paix of steel plates which absor~s vibrations more than an ordinary steel plate.
In this construction, however/ although the primary noises caused by the vihrations of the side walls 2 covered ~y t~e sound insulation panels 4 are attenuated sufficiently, ~h t is called the secondary noises radiated hy th.e vihxations of the sound insulation panels 4 in which the vi~rations are transmitted from the side walls 2 through.the re.inforcing channels 3 as shown by the arrow B are hardly reduced.
According to the emhodimen~ under considera-tion, vi~ration sensors S and vibrators 6 are mounted on th.e sound insulation panels 4, so that detection signals from the vibration sensors 5 are applied to a control signal generator 7, which in turn applies a control signal to the vibrators 6 through an amplifier 8. The vibration transmitted from the reinorcing channels 3 to the sound insulation panels 4 is thus detected by the vibration sensors 5 and a control signal corresponding to the detection signal is generated by the generator 7, which signal, after being amplified by the amplifier 8, is applied to the vibrators 6 to generate vibrations of the phase opposite to the vibrations transmitted to the sound insulation panels 4, thereby cancelling the vibrations of the sound insulation panels 4.
The circuit configuration and the operation of the control signal generator, the amplifier and the vibrators are essentially identical to those of similar devices disclosed in the aforesaid European patent appli-cation, except that according to the present invention, the vibrators are adapted to reduce the vibrations transmitted to the sound insulation panels but not the vibrations of the tank itsel and therefore a smaller number of vibrators with a smaller power are used to achieve the object of the invention.
The vibration sensors 4 and the vibrators 5 are mounted on the sound insulation panels 4 in such a manner of construction as shown in Figure 3. Each of the vibration sensors 5 and the vibrators 6 is held on a mounting plate 9, which is bolted replaceably to the sound insulation panel 4 so that the vibration sensor 5 and the vibrator 6 are situated in the space between the '~
1 sound insulation panel 4 and the side plate 2 through a hole 10. Lead wires 11, 12 from the vibration sensor 5 and the vibrator 6 are led through a hole 13 into a reinforcing channel 3 and after being wired therein, are connected to the control signal generabor 7 and the amplifier 8 together with the lead wires of the other vibration sensors and vi~rators.
The advantages of the present invention are described below.
(1] The sound insulation panel 4, which does not participate in the strength of the tank, may ~e made of a comparatively thin plate and is capa~le of reducing the vibrations with a small control power as compared with the conventional method in whic~ the control power is applied directly to the outer surface of t~e tank.
t2~ Since the vibrations of the reinforcing channel of comparatively simplified construction provide a source of vi~rations of the sound insulation panel, a smaller number of frequency components are contained 2a than the vi~rations of the induction apparatus, and therefore a smaller numher of vi~rators are required than when the vibrations of the induction apparatus are cancelled directly.
A simple noise-reduction method for stationary induction apparatuses overcoming the above-mentioned dis-advantages in which the noises are cancelled ~y a sound of the phase oposite to the noises of the stationary induction apparatus involved has been suggested by Japanese Patent Publication No. 417/58 of General Electric Company published January 28, 1958. This method, however~ is not yet practically used in view of the fact that the noises generated by an induction apparatus, which is complicated in construction, include a multiplicity of frequency components, thereby making it necessary to provide separate loud speakers for different frequency components, with the result that an increased number of loud speakers are lQ required on the one hand and the adjustment of the frequency and sound volume is complicated on the other hand A method to improve this disadvantage is disclosed in European patent application No. 0043565 by Yasuro Hori et al published January 13, 1982 and entitled "Vibration/
Noise Reduction Device for Electrical Apparatus", in which the vibrations generated in an induction apparatus are detected and the frequen~y components of the vibrations are determined by Fourier transformation, so that additional vibrations are applied in a manner to cancel the vibrations of the respective frequency components by vibrators mounted on the induction apparatus. This system also requires a number of vibrators as in the case of the above-mentioned Japanese Patent Publication. Further, vibrators of larger power is required to cancel the vibrations of the ~,~
1 induction apparatus.
U.S. Patent co-pending Application Serial No.
406,564 filed August 9, 1982 by Syuya Hagiwara and Yasuro Hori and entitled "Method and Apparatus for Reducing Vibrations of Stationary Induction Apparatus" also discloses a system similar to the one disclosed in U.S.
Patent Application Serial No. 27~,814, in which the phase and amplitude of the vibrations caused ~y the vibrators are adjusted advantageously. The a~ove-mentiQned problems, ho~ever, are not solved even by this suggested method.
Other conventional systems include U.S. Patent Application Serial No. 217,772 filed ~ecember 18, 1980 and entitled "Static Induction Apparatus" in which a sound-insulating plate is mounted on the framework such as areinforcing channel on thR outside surface of the tank through an elastic memher there~y to reduce the noises produced from the tank, and Japanese Patent Puhlication No. 873a6/81 entitled l'Static Induction Apparatus" in 2~ which a similar sound-insulation panel is provided with a weighty material there~y to reduce the vibrations trans mitted from the tank through the reinforcing channel to the sound insulation panel. The former method has the disadvanta~e that although the noises (primary noises~
radiated by way of the outer wall of the tank through the oil from the winding and core are capa~le of ~eing reduced, it is impossi~le to reduce the noises (secondary noises~ caused by th~ vibrations of the sound lnsulation 1 panels in which the vibrations are transmitted from -the outer wall of the tank through the reinforcing channel.
In the latter method Gomprising a sound insulation panel and a weighty material combined which is intended to reduce the secondarv noises, on the other hand, the noise reduction level is limited by the physical limita-tions of the strength or dimensions of the elastic member for carrying the sound insulation panels or the size of the weighty material.
An object of the present invention is to provide a noise-reduction device for stationary induction appara-tuses, which obviates the disadvantages of the prior art de-vices and effectively reduces the noises caused by the tank.
- In order to achieve this object, aGcording to the present invention, there is provided a noise-reduction device, in which the primary noises radiated from the outer wall of the tank are pxevented by sound insulation panels mounted on the outer wall of the tank through a framework such as reinforcing channels, and vibration cancelling means including vibration sensors and vibrators are mounted on the sound insulation panels, so that the controlling force of a phase opposite -to the vibratlon transmitted from the tank through the reinforcing channel to the sound insulation panels causing the secondary noises is applied thereto, thus maklng it possible to cancel the vibrations by a smaller number of vibrators with a smaller controlling force than when the controlling force is applied directly to the tank.
,3 1 The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:
Fig. 1 is a partly cut-away side view showing the general construction of a noise reduction device for a transformer according to an embodiment of the present invention;
Fig. 2 is a partly cut-away perspective view of a-noise reduction device on which sound insulation panels and reinforcing channels are mounted;
Fig. 3 is a enlarged sectional view at lef.t hand portion of Fig. 1, Fig. 4 i5 a perspective view of the essential parts showing a configuration of a noise reduction device for a transformer according to another embodiment of the present invention~ and Fig. 5 is a central longitudinal sectional view 2~ taken parallel to t~e tank plan view with the noise reduction device of Fig. 4 mounted on the tank through the reinforcing frames, An embodiment of the. present invention will he described below with reference to Figs. 1, 2 and 3.
In these figures, reference numeral 1 designates a transformer tank containing a winding and core 18 and filled with an insulating oil 1~. At least a pair of reinforcing channels 3 of U-sh.aped steel surrounding the 1 tank 1 are securely welded to th.e side walls 2 of the tank 1 thereby to reinforce the tank 1. A plurarity of sound-insulation panels 4 surrounding -the whole periphery of the tank including the main vihration section providing a noise source are mounted in such a manner as to close the part of the side walls 2 between the reinforcing channels 3. At the part of the side walls 2 which is covered by the sound insulation panels 4, as shown by the arrow A in Fig. 3, the primary noises radiated by the vibrations generated from the winding and core 1~ and transmitted to the side walls 2 through the insulating oil 1~ are blocked hy the sound insulation panels 4.
The sound insulation panels 4 is preferably made of highly damped plate with resin sandwiched between a paix of steel plates which absor~s vibrations more than an ordinary steel plate.
In this construction, however/ although the primary noises caused by the vihrations of the side walls 2 covered ~y t~e sound insulation panels 4 are attenuated sufficiently, ~h t is called the secondary noises radiated hy th.e vihxations of the sound insulation panels 4 in which the vi~rations are transmitted from the side walls 2 through.the re.inforcing channels 3 as shown by the arrow B are hardly reduced.
According to the emhodimen~ under considera-tion, vi~ration sensors S and vibrators 6 are mounted on th.e sound insulation panels 4, so that detection signals from the vibration sensors 5 are applied to a control signal generator 7, which in turn applies a control signal to the vibrators 6 through an amplifier 8. The vibration transmitted from the reinorcing channels 3 to the sound insulation panels 4 is thus detected by the vibration sensors 5 and a control signal corresponding to the detection signal is generated by the generator 7, which signal, after being amplified by the amplifier 8, is applied to the vibrators 6 to generate vibrations of the phase opposite to the vibrations transmitted to the sound insulation panels 4, thereby cancelling the vibrations of the sound insulation panels 4.
The circuit configuration and the operation of the control signal generator, the amplifier and the vibrators are essentially identical to those of similar devices disclosed in the aforesaid European patent appli-cation, except that according to the present invention, the vibrators are adapted to reduce the vibrations transmitted to the sound insulation panels but not the vibrations of the tank itsel and therefore a smaller number of vibrators with a smaller power are used to achieve the object of the invention.
The vibration sensors 4 and the vibrators 5 are mounted on the sound insulation panels 4 in such a manner of construction as shown in Figure 3. Each of the vibration sensors 5 and the vibrators 6 is held on a mounting plate 9, which is bolted replaceably to the sound insulation panel 4 so that the vibration sensor 5 and the vibrator 6 are situated in the space between the '~
1 sound insulation panel 4 and the side plate 2 through a hole 10. Lead wires 11, 12 from the vibration sensor 5 and the vibrator 6 are led through a hole 13 into a reinforcing channel 3 and after being wired therein, are connected to the control signal generabor 7 and the amplifier 8 together with the lead wires of the other vibration sensors and vi~rators.
The advantages of the present invention are described below.
(1] The sound insulation panel 4, which does not participate in the strength of the tank, may ~e made of a comparatively thin plate and is capa~le of reducing the vibrations with a small control power as compared with the conventional method in whic~ the control power is applied directly to the outer surface of t~e tank.
t2~ Since the vibrations of the reinforcing channel of comparatively simplified construction provide a source of vi~rations of the sound insulation panel, a smaller number of frequency components are contained 2a than the vi~rations of the induction apparatus, and therefore a smaller numher of vi~rators are required than when the vibrations of the induction apparatus are cancelled directly.
(3) The vihration sensors 5 and the vihrators 6 are ea5ily removahle from t~e sound insulation panels 4 and therefore the maintenance and inspection thereof are easy.
(4~ The vi~ration cancelling devices includîng l the vi~ration sensors 5 and the vi~rators 6 are contained in the space surrounded by the tank side walls 2 and the reinforcing channels 3, and therefore the tank dimension is not substantially increased. Further~ the vibration cancelling devices, which are enclosed by the sound insulation panels 4 and the mounting plates 9, are not exposed to the elements and have a longer service life.
(5~ The lead wires ll and 12 of the vibration sensor 5 and the vi~rator 6 are wired through the channel 3, thus eliminating the need of an exclusive piping for the lead wires.
Another em~odiment of the present invention will ~e described ~ith reference to Figs. 4 and 5O In this emhodiment, the. sound insulation panel 4 is mounted on the reinforcing channels 3 through a frame 14 and a flexi~le thin plate. 15. T~e vi~ration sensor 5 and the vibrator 6 are mounted on the frame 14 through mounting frames 16. The vibration sensor 5 and t.he vi~rator 6 alternatively may ~e mounted directly on the frame 14 without the mounting frame 16. Numeral 17 designates an inspection cover.
In this construction, the frame 14 and the thin plate 15 function as a ~eighty mem~er and a spring res-pe.ctively thereby to reduce the transmission of the vibrations from the reinorcing channel 3. The vibration reduce effect may be increased by reducing the spring constant of the thin plate 15 and increasing the weight of the frame 14. The limïtation of the strength and 1 dimensions, however, limit the vibration damping effect.
Accordin~ to the presen~ embodiment, the vib-rators 6 are mounted on the frame 14 through the mounting frame 16 so that the force of -the phase opposite to thP
vihrations applied through the reinforcing channels 3 is applied to the tank 1 there~y to cancel -the vibrations thereof, thus cancelling the vi~rations of the sound insulation panel~ 4 and the inspection cover 17 connected with the frame 14.
Each vihrator 6 is mounted on the frama 14 by reason of the fact that the frame 14 has a larger rigidity than the sound insulation panel 4, resulting in a smaller number of natural vibration frequencies in the frequency ranga to be reduced. Specifically, when cancelling the vibrations o~ a structure by applying a control force th.ereto, vîbrators as many as number of the natural vihration fxequencies are theoretically required. When the vi~rators 6 are mounted, not on the sound insulation panel 4, ~ut on the frame 14 which is larger in rigidity, a smaller number of natural vibration fre~uencies to ~e reduced are involved, t~us making i-t possi~le -to reduce the vibrations with a smaller num~er of vlbrators 6. The em~odiment under considera-tion, which uses a control signal generator, an amplifier and vibrators similar to those of the ~irst em~odiment, has the advantages mentioned below.
(11 As in th.e flrst e-m~odiment, only the power sufficient to cancel th~ vi~rations o~ t~le sound ~ 10 ~
1 i~sulation panels are required and therefore the output power of the vibrators is reduced.
(2) Since the vi~rations of the sound insulation panels 4 are controlled hy the frame 14 larger in rigidity and smaller in the num~er of natural vi~ration frequencies to be reduced, the num~er of the frequency components of the vi~rations to ~e cancelled is further decreased as compared with the first embodiment, thus reducing the num~er of vi~rators required.
(3) The sound insulation panel 4 is supported from the reinforcing channel 3 ~y a spring of the thin plate 15, and therefore the vi~ration system of the sound insulation panel 4 may be considered substantially independently of the reinforcing channel 3, there~y clarifying and making it easy to predict the vibration characteristics of the sound insulation panel 4. This facilitates the vibration control on the one hand and improves the stability of vi~ration control on t~e other hand.
(4~ By removing the in~pection covers 17, the maintenance and .inspection of the vi~ration sensors S
and th.e vibrators ~ are easily carried out.
(5l In view~of th.e. fact that the vi~ration cancelling devices including t~e vi~ration sensors 5, t~e vi~rators 5 and the frame 14 are contained in the space surrounded by the tank side plate.s 2 and the reinforcing c~annels 3, the tank dimension is not generally increased. Furthe.r, since the vi~ration cancelling devices are ~ermetically l enclosed ~y the sound insulation panels 4, the thln plates 15 and the inspection covers 17, the vibration cancelling devices are not exposed to the elements, thus ensuring the long service life thereof~
(6) The fact that the vi~rators 6 are mounted through the mounting frames 16 makes it possibl.e to control a plurality of points ~four points in the case of Fig. 42 ~y a single vi~rator 6, thus increasing the vibration reducing effect.
It will he understood from the foregoing des-cription that according to the present invention, the primary noises radiated from the surface of the tank are reduced by sound insulation panels mounted on the outer walls of the tank through framework such as reinfoclng channels on the one hand, the vi~ration cancelling devices including vibration sensors and vi~rators are mounted on sound insulation panels or weighty members installed on the sound insulation panels there~y ~o apply the control~
ling force of opposite phase to the vi~rations transmitted to th.e sound insulation panels through. the reinforcing channels from the tank causing the secondary noises on t~e other h.and. A5 compared with the prior art devices in which the controlling force is applied directly to the tank, the noises gene.rated from the tank are effectively reduced ~y a small num~er of vi~rators with smaller power~
(4~ The vi~ration cancelling devices includîng l the vi~ration sensors 5 and the vi~rators 6 are contained in the space surrounded by the tank side walls 2 and the reinforcing channels 3, and therefore the tank dimension is not substantially increased. Further~ the vibration cancelling devices, which are enclosed by the sound insulation panels 4 and the mounting plates 9, are not exposed to the elements and have a longer service life.
(5~ The lead wires ll and 12 of the vibration sensor 5 and the vi~rator 6 are wired through the channel 3, thus eliminating the need of an exclusive piping for the lead wires.
Another em~odiment of the present invention will ~e described ~ith reference to Figs. 4 and 5O In this emhodiment, the. sound insulation panel 4 is mounted on the reinforcing channels 3 through a frame 14 and a flexi~le thin plate. 15. T~e vi~ration sensor 5 and the vibrator 6 are mounted on the frame 14 through mounting frames 16. The vibration sensor 5 and t.he vi~rator 6 alternatively may ~e mounted directly on the frame 14 without the mounting frame 16. Numeral 17 designates an inspection cover.
In this construction, the frame 14 and the thin plate 15 function as a ~eighty mem~er and a spring res-pe.ctively thereby to reduce the transmission of the vibrations from the reinorcing channel 3. The vibration reduce effect may be increased by reducing the spring constant of the thin plate 15 and increasing the weight of the frame 14. The limïtation of the strength and 1 dimensions, however, limit the vibration damping effect.
Accordin~ to the presen~ embodiment, the vib-rators 6 are mounted on the frame 14 through the mounting frame 16 so that the force of -the phase opposite to thP
vihrations applied through the reinforcing channels 3 is applied to the tank 1 there~y to cancel -the vibrations thereof, thus cancelling the vi~rations of the sound insulation panel~ 4 and the inspection cover 17 connected with the frame 14.
Each vihrator 6 is mounted on the frama 14 by reason of the fact that the frame 14 has a larger rigidity than the sound insulation panel 4, resulting in a smaller number of natural vibration frequencies in the frequency ranga to be reduced. Specifically, when cancelling the vibrations o~ a structure by applying a control force th.ereto, vîbrators as many as number of the natural vihration fxequencies are theoretically required. When the vi~rators 6 are mounted, not on the sound insulation panel 4, ~ut on the frame 14 which is larger in rigidity, a smaller number of natural vibration fre~uencies to ~e reduced are involved, t~us making i-t possi~le -to reduce the vibrations with a smaller num~er of vlbrators 6. The em~odiment under considera-tion, which uses a control signal generator, an amplifier and vibrators similar to those of the ~irst em~odiment, has the advantages mentioned below.
(11 As in th.e flrst e-m~odiment, only the power sufficient to cancel th~ vi~rations o~ t~le sound ~ 10 ~
1 i~sulation panels are required and therefore the output power of the vibrators is reduced.
(2) Since the vi~rations of the sound insulation panels 4 are controlled hy the frame 14 larger in rigidity and smaller in the num~er of natural vi~ration frequencies to be reduced, the num~er of the frequency components of the vi~rations to ~e cancelled is further decreased as compared with the first embodiment, thus reducing the num~er of vi~rators required.
(3) The sound insulation panel 4 is supported from the reinforcing channel 3 ~y a spring of the thin plate 15, and therefore the vi~ration system of the sound insulation panel 4 may be considered substantially independently of the reinforcing channel 3, there~y clarifying and making it easy to predict the vibration characteristics of the sound insulation panel 4. This facilitates the vibration control on the one hand and improves the stability of vi~ration control on t~e other hand.
(4~ By removing the in~pection covers 17, the maintenance and .inspection of the vi~ration sensors S
and th.e vibrators ~ are easily carried out.
(5l In view~of th.e. fact that the vi~ration cancelling devices including t~e vi~ration sensors 5, t~e vi~rators 5 and the frame 14 are contained in the space surrounded by the tank side plate.s 2 and the reinforcing c~annels 3, the tank dimension is not generally increased. Furthe.r, since the vi~ration cancelling devices are ~ermetically l enclosed ~y the sound insulation panels 4, the thln plates 15 and the inspection covers 17, the vibration cancelling devices are not exposed to the elements, thus ensuring the long service life thereof~
(6) The fact that the vi~rators 6 are mounted through the mounting frames 16 makes it possibl.e to control a plurality of points ~four points in the case of Fig. 42 ~y a single vi~rator 6, thus increasing the vibration reducing effect.
It will he understood from the foregoing des-cription that according to the present invention, the primary noises radiated from the surface of the tank are reduced by sound insulation panels mounted on the outer walls of the tank through framework such as reinfoclng channels on the one hand, the vi~ration cancelling devices including vibration sensors and vi~rators are mounted on sound insulation panels or weighty members installed on the sound insulation panels there~y ~o apply the control~
ling force of opposite phase to the vi~rations transmitted to th.e sound insulation panels through. the reinforcing channels from the tank causing the secondary noises on t~e other h.and. A5 compared with the prior art devices in which the controlling force is applied directly to the tank, the noises gene.rated from the tank are effectively reduced ~y a small num~er of vi~rators with smaller power~
Claims (6)
1. A noise-reduction device for a stationary induction apparatus comprising a tank filled with the insulating oil and an induction apparatus mounted in said tank, said noise-reduction device comprising:
first means mounted on at least two reinforcing channels arranged substantially parallely to each other in spaced relationship therebetween on side walls of said tank in a manner to surround said tank, said first means including sound insulation panels provided to surround the part of said tank side walls between said reinforcing channels, thereby reducing the noises generated from said winding and core and radiating outside through said insulating oil and said tank side walls; and second means for cancelling the vibrations of said sound insulation panels, including a plurality of vibration sensors for detecting the vibrations of said sound insulation panels, a plurality of vibrators for applying to said sound insulation panels such vibrations as to cancel the frequency components of the vibrations detected by said vibration sensors respectively.
first means mounted on at least two reinforcing channels arranged substantially parallely to each other in spaced relationship therebetween on side walls of said tank in a manner to surround said tank, said first means including sound insulation panels provided to surround the part of said tank side walls between said reinforcing channels, thereby reducing the noises generated from said winding and core and radiating outside through said insulating oil and said tank side walls; and second means for cancelling the vibrations of said sound insulation panels, including a plurality of vibration sensors for detecting the vibrations of said sound insulation panels, a plurality of vibrators for applying to said sound insulation panels such vibrations as to cancel the frequency components of the vibrations detected by said vibration sensors respectively.
2. A noise reduction-device for a stationary induction apparatus according to Claim 1, wherein said sound insulation panels arranged substantially parallelly with said tank side walls form a space with said tank side walls.
3. A noise-reduction device for a stationary induction apparatus according to Claim 2, wherein said vibrators are mounted with said sound insulation panels in the space between said tank side walls and said sound insulation panels.
4. A noise-reduction device for a stationary induction apparatus according to Claim 2, wherein each of said vibrators is mounted on a plate member mounted removably on said sound insulation panel in a manner to enclose the opening formed in each of said sound insulation panels.
5. A noise-reduction device for a stationary induction apparatus according to Claim 1, comprising a flexible member through which each of said sound insulation panels is mounted on said reinforcing channel, and a weighty member on which said vibrator is mounted, said weighty member being located at the junction of each of said sound insulation panels and said flexible member.
6. A noise-reduction device for a stationary induction apparatus according to Claim 5, wherein each of said sound insulation panels includes a peep hole for said vibrators, said peep hole being closed with a cover.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56192844A JPS5895806A (en) | 1981-12-02 | 1981-12-02 | Noiseproof device for stationary induction apparatus |
| JP192844/81 | 1981-12-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1181013A true CA1181013A (en) | 1985-01-15 |
Family
ID=16297911
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000416574A Expired CA1181013A (en) | 1981-12-02 | 1982-11-29 | Noise-reduction device for stationary induction apparatus |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0083718A1 (en) |
| JP (1) | JPS5895806A (en) |
| CA (1) | CA1181013A (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6120790A (en) * | 1984-07-10 | 1986-01-29 | Canon Inc | Printing head for wire dot recorder |
| FR2632474B1 (en) * | 1988-06-01 | 1991-04-26 | Saint Louis Inst | DEVICE FOR ACTIVE MITIGATION OF VIBRATION AND IN PARTICULAR NOISE WITHOUT ACOUSTIC DELAY |
| GB2260874A (en) * | 1991-10-21 | 1993-04-28 | Marconi Gec Ltd | A sound control device |
| JPH0661073A (en) * | 1992-08-03 | 1994-03-04 | Chubu Electric Power Co Inc | Noise reduction equipment for power transformer |
| EP0664044B1 (en) * | 1992-10-08 | 1999-09-15 | NCT Group, Inc. | Active acoustic transmission loss box |
| EP0746843B1 (en) * | 1993-09-09 | 2001-11-14 | NCT Group, Inc. | Global quieting system for stationary induction apparatus |
| NL1023559C2 (en) * | 2003-05-28 | 2004-11-30 | Tno | Semi-finished product intended to be mounted on a vibrating wall or panel for actively damping vibrations of the wall, wall or panel provided with such a semi-finished product, system provided with a semi-finished product and a control unit, wall or panel provided with a control unit and method for damping audible vibrations from a wall or panel. |
| ATE481704T1 (en) * | 2008-07-03 | 2010-10-15 | Preform Gmbh | ADAPTIVE NOISE GENERATING DEVICE |
| BRPI0823295A2 (en) * | 2008-12-04 | 2015-06-23 | Abb Technology Ag | Induction device |
| WO2016147158A1 (en) * | 2015-03-18 | 2016-09-22 | Efacec Energia - Máquinas E Equipamentos Eléctricos S.A. | Oil immersed power transformer tank wall |
| CN105609236B (en) * | 2016-01-19 | 2017-11-14 | 株洲南车时代电气股份有限公司 | A kind of train current transformer auxiliary transformer erecting device |
| CN106847254A (en) * | 2017-03-17 | 2017-06-13 | 浙江大学 | A kind of locality active noise reduction system |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2776020A (en) * | 1955-02-09 | 1957-01-01 | Gen Electric | Noise reducing system for transformers |
| DE1227142B (en) * | 1964-03-13 | 1966-10-20 | Smit & Willem & Co Nv | Device for noise reduction in transformers and reactors |
| US4025724A (en) * | 1975-08-12 | 1977-05-24 | Westinghouse Electric Corporation | Noise cancellation apparatus |
| WO1981001479A1 (en) * | 1979-11-10 | 1981-05-28 | Sound Attenuators Ltd | The cancelling of vibrations transmitted through a fluid in a containing vessel |
| JPS5910568B2 (en) * | 1979-12-18 | 1984-03-09 | 株式会社日立製作所 | stationary induction appliance |
-
1981
- 1981-12-02 JP JP56192844A patent/JPS5895806A/en active Pending
-
1982
- 1982-11-23 EP EP82110831A patent/EP0083718A1/en not_active Withdrawn
- 1982-11-29 CA CA000416574A patent/CA1181013A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0083718A1 (en) | 1983-07-20 |
| JPS5895806A (en) | 1983-06-07 |
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