EP4652619A1

EP4652619A1 - Device for reducing noise caused by a transformer and system

Info

Publication number: EP4652619A1
Application number: EP24700637.2A
Authority: EP
Inventors: Michal Kozupa; Grzegorz Kmita; Pawel ZALUSKI; Robert Platek; Akshaya KULKARNI
Original assignee: Hitachi Energy Ltd
Current assignee: Hitachi Energy Ltd
Priority date: 2023-01-20
Filing date: 2024-01-19
Publication date: 2025-11-26
Also published as: EP4404221A1; KR20250110916A; WO2024153808A1; CN120569794A

Abstract

The present disclosure relates to a device (10) for reducing noise caused by a transformer (12), including at least one sound-reducing element (16) configured to be arranged on an exterior of the transformer (12) and including at least one duct (18) arranged in a meandering pattern and configured to attenuate one or more soundwaves received from the transformer (12). The present disclosure also relates to an assembly (70), an enclosure (70), and a system including at least one transformer (12) and at least one device (10) and/or at least one assembly (70) and/or at least one enclosure (70) according to any of the embodiments described herein which is/are arranged on an exterior of the at least one transformer (12).

Description

DEVICE FOR REDUCING NOISE CAUSED BY A TRANSFORMER AND SYSTEM

Background

Transformers are widely used to convert electricity from a first voltage level to a second voltage level, the second voltage level being either similar, higher or lower than the first voltage level. During operation, transformers may generate and emit a considerable amount of noise, in particular audible noise, which may have one or more adverse effects, in particular on an environment of the transformer. For instance, the noise may be uncomfortable and/or annoying and/or harmful and/or painful to persons who may be subjected to the noise, in particularfor an extended period of time. Moreover, for instance, the soundwaves emitted by the transformer may be coupled to one or more vibrations, e.g., by exciting one or more surfaces, which may also have one or more adverse effects in the environment.

As transformers have become more compact and are limited by their respective footprint, it may be desirable to provide a relatively compact means for reducing the noise caused by transformers. Additionally, or alternatively, it may be desirable to provide a relatively effective and/or efficient means for reducing noise caused by transformers.

However, the known prior art has not, or at least not sufficiently, provided means for reducing noise caused by transformers to the desired extent, e.g., by addressing one or more of the above-identified issues.

Thus, the present disclosure describes one or more aspects for providing improved means for reducing noise caused by a transformer.

The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

Various exemplary embodiments of the present disclosure disclosed herein are directed to providing features that will become readily apparent by reference to the following description when taken in conjunction with the accompanying drawings. In accordance with various embodiments, exemplary devices are disclosed herein. It is understood, however, that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of the present disclosure.

Thus, the present disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

Description of the Drawings

Fig. 1 schematically shows, in a top view, a device for reducing noise caused by a transformer according to an embodiment of the present disclosure;

Fig. 2 shows a diagram of a pressure distribution in a duct of the device shown in Fig. 1;

Fig. 3 shows a diagram of a particle velocity distribution in a duct of the device shown in

Fig. 1;

Fig. 4 schematically shows the device of Fig. 1 in a first arrangement according to an embodiment of the present disclosure;

Fig. 5 schematically shows the device of Fig. 1 in a further arrangement according to an embodiment of the present disclosure;

Fig. 6 schematically shows the device of Fig. 1 in a further arrangement according to an embodiment of the present disclosure;

Fig. 7 schematically shows an enclosure which includes a plurality of the device of Fig. 1.

In the following, exemplary embodiments of the disclosure will be described. It is noted that some aspects of any one of the described embodiments may also be found in some other embodiments unless otherwise stated or obvious. However, for increased intelligibility, each aspect will only be described in detail when first mentioned and any repeated description of the same aspect will be omitted.

The present disclosure relates to a device for reducing noise, in particular audible noise, caused by a transformer. The device may include at least one sound-reducing element. The at least one sound-reducing element may be configured to be arranged on an exterior of the transformer, e.g., on or at an outer side, e.g., an outer surface, of a tank of the transformer. Alternatively, or additionally, the at least one sound-reducing element may be configured to be arranged at least partially in an interior of the transformer, e.g., within a tank of the transformer. The at least one sound-reducing element may include at least one duct. The at least one duct may be arranged in a meandering pattern. The at least one duct may be configured to attenuate one or more soundwaves received from the transformer to reduce noise of the transformer.

Configuring the at least one sound-reducing element with the at least one duct and configuring the at least one duct to receive one or more soundwaves from the transformer may allow the at least one duct to interact with the one or more soundwaves from the transformer to reduce noise of the transformer. For instance, the at least one duct may at least partially trap at least a portion of the soundwaves within the at least one duct, at least temporarily, and/or the at least one duct may interact with the one or more soundwaves to cause a change in one or more properties of the one or more soundwaves, e.g., in at least one amplitude of the one or more soundwaves. Alternatively, or additionally, the at least one duct may be configured to reduce a velocity of at least one medium, e.g., air, in particular of one or more particles of the at least one medium, in which the soundwaves are propagated, e.g., via friction between the medium and at least a section of the at least one sound-reducing element, e.g., at least one wall which borders and/or defines the at least one duct. For instance, this may cause damping of the one or more soundwaves to reduce and/or mitigate and/or attenuate noise caused by the transformer. Alternatively, or additionally, a plurality of the soundwaves may at least partially cancel each other out within the at least one duct. Thus, this may allow the noise generated by the transformer to be reduced relatively effectively and/or efficiently.

Transformers known from the prior art are generally sound dampened (also referred to as "sound deadening") using one or more materials which are relatively heavy and/or dense, in particular to reduce noise caused by the transformer, including at low frequencies. The present inventors have surprisingly discovered that the device disclosed herein may provide lighter and/or less dense means for reducing noise caused by the transformer. Instead of relying on a relatively heavy mass and/or a relatively high density of sound reducing material, the present inventors have discovered that the device described herein may be tailored (see the description further below for more details) to one or more frequencies and/or a relatively narrow range of frequencies, including relatively low frequencies, e.g., ratherthan attempting to provide a relatively high effectiveness across a relatively broad range of frequencies, since this may be superfluous, as the inventors have discovered that the noise caused by transformers is often dominated by a relatively small number or relatively narrow range of frequencies which can efficiently and effectively be reduced by the device described herein using a lower mass or density than the sound damping material known from the prior art.

Moreover, the present inventors have surprisingly discovered that the device for reducing noise caused by a transformer, as described herein, may more efficiently and/or more effectively reduce noise caused by a transformer in general, in particular frequencies which are relatively difficult to dampen, in particular by conventional damping means, e.g., mineral wool, in particular at lower frequencies (e.g., 100/120 Hz, 200/240 Hz, 300/360 Hz, but also optionally to a certain extent up to 500/560 Hz) compared with the prior art which use conventional sound reducing material. In particular, the device described herein shows improved performance to dampen low noise tones, in particular 100/120 Hz and first orders harmonics.

In particular, the device for reducing noise caused by a transformer, as described herein, may reduce, i.e., dampen, so called "pure tone noise", e.g., 2 x the network frequency = 2 x 50 Hz in the EU, 2 x 60 Hz in North America, as opposed to reducing or damping broadband noise via conventional sound damping material in the prior art.

The term "meandering pattern" may be understood such that the at least one duct may follow a path which causes the one or more soundwaves to be continuously, for at least one or more sections of the at least one duct, or discontinuously, for at least one or more sections of the at least one duct, redirected. In other words, the "meandering pattern" of the at least one duct may cause a direction in which the one or more soundwaves propagate, or a medium such as air may travel, through the at least one duct to be changed/altered, continuously, for at least one or more sections of the at least one duct, or discontinuously, for at least one or more sections of the at least one duct. For instance, the meandering pattern may be configured as a spiral, a swirl, a maze, a wave, or any other path which continuously and/or non-continuously causes a change in the direction of the at least one duct. In particular, the at least one duct may be configured to redirect the one or more soundwaves along a path of propagation of the one or more soundwaves through the at least one duct at least 2 times, more particularly at least 3 times, more particularly at least 4 times, more particularly at least 5 times. Alternatively, or additionally, the at least one duct may be configured to redirect the one or more soundwaves continuously along at least a section of the at least one duct, e.g., by a curved and/or spiral form of the at least one section of the at least one duct. The at least one duct may include at least one curved section and/or at least one curved and/or angled section, e.g., at least one section which is angled in a range from 1° to 180°, particularly from 45° to 180°, more particularly from 90° to 180°, for redirecting the one or more soundwaves through the at least one duct. The at least one duct may extend concentrically for at least a section thereof and/or non-concentrically for at least a section thereof.

Arranging the at least one duct in a meandering pattern may allow the at least one duct to be configured relatively compactly, e.g., compared with a duct which extends in a substantially straight line, while providing a relatively effective and/or efficient reduction in noise caused by the transformer. This may allow the at least one duct to be configured to be relatively long and/or have a relatively large volume/space, while minimizing the space/volume which the at least one sound-reducing element, in particular the at least one duct, consumes. Hence, this may provide a space-spacing means for effectively and/or efficiently reducing noise caused by transformers.

Various embodiments may preferably implement one or more of the following features:

The at least one sound-reducing element may be configured as an insert which may be mounted, preferably releasably mounted, e.g., to at least one support structure and/or directly to at least one surface, preferably at least one outer surface, of the transformer.

The at least one sound-reducing element may be arranged, positioned and/or oriented, e.g., relative to the transformer, in a number of ways. For instance, the sound-reducing elements may be arranged without spacing between adjacent sound-reducing elements. Alternatively, the sound-reducing elements may be arranged periodically and/or spaced apart from each other, e.g., at one or more intervals. Additionally, or alternatively, the sound-reducing elements may be arranged according to and/or matching a shape or contour, in particular an outer contour, of the transformer. The sound-reducing elements may be arranged in-line, e.g., in a straight line, and/or along a curve or bend, etc.

The device disclosed herein may be used with any type of transformer to reduce noise of the respective transformer. Thus, the device disclosed herein is not limited to an application with one or more specific types of transformers. For instance, the transformer may be a reactor.

The at least one duct may include at least one inlet opening configured to receive one or more soundwaves from the transformer. Each duct may include a closed end. Configuring the end(s) of the duct(s) to be closed may enhance the efficiency and/or effectiveness of the device in providing a resonance damping effect, in particular with respect to one or more frequencies and/or one or more frequency ranges for which one or more properties of the duct, e.g., a length of the duct, are specifically configured and/ortailored to attenuate, e.g., a first acoustic harmonic frequency.

Each end of each duct may be closed. The "end" of each duct refers to an end of the duct which the soundwaves eventually reach, after the soundwaves have entered the duct. The soundwaves may be reflected off of the (closed) end. Hence, the inlet opening of the duct is not understood as an "end" of the duct. In other words, the "end" of each duct refers to an end of the respective duct which is opposite from the inlet opening. In other words, the "end" of the duct refers to a downstream end of the duct.

The at least one inlet opening may face the transformer, when the at least one sound-reducing element is arranged on the exterior of the transformer. This may facilitate receiving the soundwaves from the transformer. Moreover, configuring the at least one inlet opening to face the transformer, when the at least one sound-reducing element is arranged on the exterior of the transformer, in combination with configuring each duet to include a closed end, in particular configuring each end of each duct to be closed, may be advantageous, in particular since this allows the entrance of the closed end duct to directly face the transformer, e.g., a wall of the transformer, which may (further) increase an efficiency and/or effectiveness of a resonance damping effect.

The at least one sound-reducing element may have a plurality of the at least one duct. Each duct may have a total duct length. The total duct lengths of the ducts may be substantially identical. In other words, each duct may have substantially the same total duct length. The term "total duct length" refers to a length of a sum of all duct sections, e.g., including each section of the duct, e.g., including one or more redirections in the duct. This may increase the effectiveness and/or efficiency of the sound damping effect provided by the device, in particular with respect to one or more frequencies and/or one or more frequency ranges. In particular, this may allow the device to be tailored more precisely and/or more effectively to damping noise of one or more certain frequencies and/or frequency ranges, in particular relatively low frequencies. In particular, this may allow each duct to be specifically tailored towards one or more target frequencies or one or more target frequency ranges, i.e., the same one or more target frequencies orthe same one or more target frequency ranges, in particular frequencies or frequency ranges which are relatively difficult to dampen, rather than targeting, at least primarily, broadband noise. In particular, this may increase an efficiency and/or effectiveness of reducing, i.e., dampening, so called "pure tone noise", e.g., 2 x the network frequency = 2 x 50 Hz in the EU, 2 x 60 Hz in North America, as opposed to reducing or damping broadband noise via conventional sound damping material in the prior art.

Alternatively, the total duct lengths of the ducts may differ by no more than 30%, preferably no more than 20%, more preferably no more than 10%, preferably no more than 5%, from each other. In other words, the ducts may have varying total duct lengths, however, the total duct lengths may be within a certain range of each other, e.g., to tailor the device more precisely and/or more effectively to damping noise of one or more certain frequencies and/or frequency ranges.

The at least one inlet opening may have a smaller cross-sectional area than one or more downstream sections of the at least one duct. This may reduce a velocity of the soundwaves and/or of particles, in particular air particles, in a downstream direction within the duct, which may increase the effectiveness and/or the efficiency of the sound damping effect.

The at least one duct may be tapered, in a continuous and/or stepped manner, in an upstream direction in at least a section of the at least duct. In other words, a cross-sectional area of the duct may decrease in an upstream direction in at least a section of the duct. In other words, a cross-sectional area of the duct may increase in a downstream direction in at least a section of the duct.

Each duct may have only one open end.

The at least one duct may include at least one inlet opening which faces the transformer, when the at least one sound-reducing element is arranged on the exterior of the transformer. The at least one inlet opening may be configured to receive one or more soundwaves from the transformer. Hence, configuring the at least one duct with at least one inlet opening which faces the transformer may allow an efficient and effective entrance of the one or more soundwaves into the at least one duct. This may also reduce a distance the one or more soundwaves travel before entering the at least one duct, which may provide an optimized and/or efficient use of space of the at least one sound-reducing element, in particular of the at least one duct.

The at least one duct may include a closed end. The closed end may be arranged at the end of the path along which the one or more soundwaves propagate through the at least one duct. Thus, configuring the end of the at least one duct to be closed prevents the one or more soundwaves from exiting the at least one duct through the end. This may increase the effectiveness and/or efficiency of the at least one sound-reducing element, in particular the at least one duct, in reducing noise caused by the transformer. Moreover, this may allow the provided volume of the at least one duct to be used efficiently, since the one or more soundwaves may be reversed at the closed end to propagate at least partially through the at least one duct in a reversed direction, in which further sound-reducing effects may be applied to the one or more soundwaves. Alternatively, or additionally, a plurality of the soundwaves may at least partially cancel each other out within the at least one duct, in particular for soundwaves which are traveling in opposite directions through the at least one duct due to the closed end and its soundwave-reflecting properties. Alternatively, the at least one duct may include an open end. For instance, the at least one duct may be open at at least two ends, e.g., at an inlet and an outlet of the at least one duct.

The at least one sound-reducing element may include a plurality of walls which at least partially define the at least one duct between opposing walls of the plurality of walls. The walls may be configured to redirect the one or more soundwaves along a path of propagation of the one or more soundwaves through the at least one duct. For instance, adjacent walls, with respect to a direction along the at least one duct, may be angled relative to each other, e.g., in a range from 90° to 180°. Alternatively, or additionally, at least a section of at least one of the walls may be curved and/or bent.

At least some of the walls may be arranged substantially parallel to each other. For instance, one or more pairs of opposing walls, which define at least a section of the at least one duct, may be arranged substantially parallel to each other. Such pairs of opposing walls, which define at least a section of the at least one duct, may provide one or more substantially straight sections of the at least one duct. Alternatively, or additionally, a plurality of walls, which are arranged upstream or downstream from each other, with respect to a direction of propagation of the one or more soundwaves, may be arranged substantially parallel to each other. This may provide a plurality of sections of the at least one duct which extend substantially parallel to each other, in particular wherein the sections of the at least one duct are arranged side by side. This may provide a relatively compact sound-reducing element, more specifically a relatively compact duct.

The device may further include at least one connecting device which interconnects at least two of the walls, in particular at least two opposing walls of the plurality of walls. The at least one connecting device may be configured as a spacer. This may provide and/or maintain a certain, in particular predefined distance between the walls.

The at least one connecting device may extend substantially perpendicularly from the respective walls. The at least one duct may include a plurality of duct sections which are interconnected. At least some, in particular all, of the duct sections may extend substantially parallel to each other. In particular, at least some of the duct sections, in particular all of the duct sections, may be arranged side-by-side.

At least some, in particular all, of the duct sections may be arranged such that the one or more soundwaves are redirected from an upstream duct section of the duct sections to a downstream duct section of the duct sections by at least one angle of redirection. The angle of redirection may be at least 30°, particularly at least 40°, more particularly at least 50°, more particularly at least 60°, more particularly at least 70°, more particularly at least 80°, more particularly at least 90°, more particularly at least 100°, more particularly at least 110°, more particularly at least 120°, more particularly at least 130°, more particularly at least 140°, more particularly at least 150°, more particularly at least 160°, more particularly at least 170°, more particularly at least 180°.

The at least one sound-reducing element may be configured to be coupled to at least one support structure. The at least one support structure may be configured to be arranged, e.g., attached, on the exterior of the transformer. The at least one support structure may be configured to be coupled to an outer surface of the transformer.

The at least one support structure may be a component of the device described herein. Alternatively, the at least one support structure may be configured as a separate device/component. The at least one support structure may include one or more mounting sections on which the at least one sound-reducing element may be mounted. The at least one support structure may be configured as a housing. Alternatively, or additionally, the at least one support structure may include a plurality of slots and/or channels which may be open towards the transformer and/or an environment of the transformer.

Alternatively, the at least one support structure may be omitted. For instance, the at least one sound-reducing element may be mounted, e.g., directly, to at least one surface, preferably at least one external surface and/or at least one internal surface, of the transformer.

The at least one sound-reducing element and/or the at least one support structure may be configured modularly, e.g., such that different types of sound-reducing elements may be combined with and mounted to the at least one support structure. The different types of sound-reducing elements may vary, e.g., in the shape and/or size and/or material and/or one or more further properties of the sound-reducing elements, in particular the shape and/or size of the at least one duct provided in the respective sound-reducing elements. This may allow the sound-reducing elements to be tailored to the requirements of the respective application and/or environment of the respective transformer, e.g., the frequency or frequencies and/or amplitude(s) of the sound emitted by the respective transformer in the respective application of the transformer. However, the at least one sound-reducing element may generally be configured, in particular by configuring the at least one duct accordingly, e.g., its shape and/or size, to cover a relatively broad range of applications, e.g., frequencies and/or amplitude(s) of the sound emitted by the respective transformer, based on a single configuration of the at least one sound-reducing element. For instance, the at least one soundreducing element may be configured to reduce the noise caused by the transformer at a plurality of different frequencies and/or amplitudes of the one or more soundwaves.

The at least one support structure may partially enclose the at least one sound-reducing element, in particular a plurality of sound-reducing elements. In particular, the at least one support structure may have at least one support structure opening on a side of the at least one support structure which faces the transformer, such that the one or more soundwaves from the transformer may enter the at least one support structure via the at least one support structure opening in order to be received by the at least one duct of the at least one soundreducing element. In particular, the at least one support structure opening may extend across the entire side, or at least a relatively large area of the side, e.g., over a predefined area of the at least one support structure which faces the transformer, e.g., at least 10%, 20%, etc. of an area of the at least one support structure which faces the transformer.

The at least one support structure may be configured to be mounted on at least one exterior surface of the transformer. Alternatively, or additionally, the at least one support structure may be configured to be mounted at a distance from at least one exterior surface of the transformer. For instance, at least one gap may be arranged at least partially between the transformer and the at least one support structure.

The at least one support structure may include a plurality of channels. At least one, in particular each, of the at least one sound-reducing element may be arranged at last partially, in particular completely, within a channel of the plurality of channels. The channels thus may at least partially guide or direct the one of more soundwaves from the transformer to the respective sound-reducing element which may increase the effectiveness and/or efficiency of the at least one sound-reducing element in reducing noise caused by the transformer. A cross-section of at least a portion of at least some, in particular each, of the channels may be substantially completely filled by one or more of the at least one sound-reducing element, which may optimize a degree of reduction of noise caused by the transformer, e.g., by minimizing the portion of the one or more soundwaves which may propagate past the soundreducing elements.

The channels may be at least partially defined by a plurality of ribs extending away from the transformer, when the at least one support structure is arranged on the exterior of the transformer. The ribs may be configured to conduct and dissipate heat from the transformer to an ambient. This may allow the at least one support structure to be combined as a means for receiving/mounting the at least one sound-reducing element and a means for cooling the transformer. The ribs may be made of at least one material, e.g., a metal, which has a relatively high thermal conductivity, e.g., to provide an effective and/or efficient means for conducting heating from the transformer.

The device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be at least partially arranged or arrangeable in at least one cavity defined in the transformer and/or a tank of the transformer. This may allow the device, more specifically the at least one sound-reducing element, to be implemented in a relatively space-efficient and/or compact manner.

Alternatively, or additionally, the transformer may include a plurality of stiffening elements, preferably a plurality of stiffening ribs, configured to increase a stiffness of the transformer and/or a tank of the transformer. The device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be at least partially, in particular completely, arranged or arrangeable between adjacent stiffening elements, in particular between at least two adjacent stiffening elements, of the plurality of stiffening elements. In other words, the device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element may be arranged in one or more spaces, in particular one or more empty spaces, which are available, in particular in existing transformers. This may enable the device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, to be implemented in a relatively space-efficient and/or compact manner. This may reduce an overall volume of the transformer with the device.

The plurality of stiffening elements may be arranged on an outer or outward facing surface of the transformer, e.g., on an outer or outward facing surface of a tank of the transformer. Alternatively, or additionally, the device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be at least partially, in particular completely, arranged or arrangeable on a side of the stiffening elements which faces away from the tank of the transformer.

The plurality of stiffening elements may be elongate and/or may extend in a longitudinal direction of the transformer and/or substantially parallel to a longitudinal axis of the transformer and/or the tank of the transformer. The plurality of stiffening elements may protrude, preferably in a radial direction, from a base surface, e.g., the above-recited outer or outward facing surface, of the transformer and/or the tank of the transformer.

Alternatively, or additionally, the transformer may include a plurality of cooling fins configured to conduct and dissipate heat from the transformer, e.g., from the tank of the transformer, to an environment. The device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be arranged or arrangeable on a side of the cooling fins, which faces away from the tank of the transformer. The cooling fins may be corrugated and/or arranged in a meandering pattern. The device (for reducing noise caused by a transformer, as described herein), more specifically the at least one soundreducing element, may protrude at least partially into one or more spaces between adjacent cooling fins.

A plurality of stiffening elements configured to increase a stiffness of the transformer and/or a tank of the transformer and a plurality of cooling fins configured to conduct and dissipate heat from the transformer, such as the plurality of stiffening elements and the plurality of cooling fins as described above, may be provided. The device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be arranged at least partially between the plurality of stiffening elements and the plurality of cooling fins. For instance, the device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be arranged in a space arranged between and/or at least partially defined by the plurality of stiffening elements and the plurality of cooling fins.

The device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be in contact with the transformer, in particular with a tank, in particular with an outer surface of the tank, of the transformer. Alternatively, the device (for reducing noise caused by a transformer, as described herein), more specifically the at least one sound-reducing element, may be arranged at a distance, which is greaterthan zero, e.g., 100 cm to 200 cm, from the transformer, in particular from a tank, in particular an outer surface of the tank, of the transformer.

The transformer may be configured as a power transformer or a distribution transformer.

The device (for reducing noise caused by a transformer, as described herein) may replace the relatively thick and dense noise damping material, e.g., mineral wool, which is often used in transformers of the prior art. Hence, for instance, according to the present disclosure, the transformer may be void of additional (i.e., in addition to the device described herein) noise damping means and/or material, e.g., mineral wool. In other words, the device may replace, preferably completely, conventional sound or noise damping material used in transformers known from the prior art. The term "additional noise damping means and/or material" refers to means and/or material which are specifically configured to provide a noise damping effect, i.e., as the only or primary function of said means and/or material. In other words, components of the transformer which (at least primarily) serve a function which is different than providing a noise damping effect, e.g., a wall ortank of the transformer, is not considered to be "additional noise damping means and/or material" within the meaning of the present disclosure.

Alternatively, the device (for reducing noise caused by a transformer, as described herein) may be combined with noise damping material, i.e., conventional noise damping material. In other words, a hybrid solution which includes the device described herein and conventional noise damping material, e.g., mineral wool, may be employed. The addition of the conventional noise damping material may increase damping efficiency at higher frequencies, e.g., pure tones higher than, e.g., 300 Hz, as well a broadband noise, which may be caused by, e.g., cooling components, such as fans, motors, pumps, etc. This may allow a total mass and/or volume of the conventional noise damping material to be reduced, which may provide a relatively light structure overall, and may enhance the noise damping efficiency, in particular with respect to low pure tone noise, compared with the prior art.

The device may be configured, e.g., customized, for damping sound or noise at a particular frequency and/or at different frequencies and/or in one or more frequency ranges.

The device may be configured as a cassette or cartridge. A plurality of the devices may be arranged or configured as at least one wall. Preferably, a plurality of the devices is arranged or configured as an enclosure for at least partially, preferably completely enclosing, the transformer.

The channels may include at least one channel opening which faces towards the transformer, when the at least one support structure is arranged on the exterior of the transformer. The at least one channel opening may be substantially closed by one or more of the at least one sound-reducing element. This may force a relatively large portion of the one or more soundwaves to propagate to the at least one sound-reducing element and into the at least one duct.

The at least one duct may be at least partially filled with at least one sound-absorbing material. The at least one sound-absorbing material may be arranged proximate to the at least one inlet opening. This may further enhance the effectiveness and/or the efficiency of the at least one sound-reducing element in reducing noise caused by the transformer. For instance, the soundabsorbing material may reduce at least one amplitude of the one or more soundwaves and/or may reduce at least one velocity of at least one medium, e.g., air, in particular one or more particles of the at least one medium, in which the soundwaves are propagated. The at least one sound-absorbing material may only be arranged proximate to the at least one inlet opening. In other words, at least a second section of the duct arranged downstream from a first section of the duct proximate to the at least one inlet opening, at which the soundabsorbing material is arranged, may be void of a sound-absorbing material. The inventors have discovered that, surprisingly, sound-absorbing material arranged proximate to the at least one inlet opening may be most effective and/or efficient at damping the noise. Hence, soundabsorbing material may be omitted from the duct downstream from the first section. Alternatively, the second section of the duct may have less sound-absorbing material than the first section of the duct.

A total length and/or a width of the at least one duct may be sized based at least partially on at least one wavelength and/or at least one amplitude and/or at least one frequency, in particular one or more dominant frequencies of a plurality of frequencies, of one or more soundwaves which are emitted by the transformer. For instance, a duct length of 286 mm may be chosen, as one quarter (25%) of a wavelength of the one or more soundwaves, at a frequency of 300 Hz.

A total length of the at least one duct may be from 10% to 50%, in particular from 15% to 45%, in particular from 20% to 40%, in particular from 20% to 35%, in particular from 20% to 30%, in particular substantially 25%, of a wavelength of one or more soundwaves which are emitted by the transformer, e.g., fora frequency of the one or more soundwaves of 300 Hz. The device described herein may be tailored to provide noise reduction for soundwaves having a wide range of different frequencies and/or amplitudes.

The at least one sound-reducing element may be integrally formed. For instance, the at least one sound-reducing element may be a moulded component, e.g., by manufacturing the at least one sound-reducing element by injection moulding and/or a component made by additive manufacturing. However, the at least one sound-reducing element may be manufactured by means of a variety of further methods, e.g., by extrusion, machining, assembling the components of the at least one sound-reducing element, e.g., adhesively, etc.

The at least one sound-reducing element may be made of any material which is suitable for the respective application. For instance, the at least one sound-reducing element may be made of at least one of the following materials: acrylonitrile styrene acrylate and a thermoplastic, in particular an amorphous thermoplastic. However, the at least one soundreducing element may be made of a variety of further materials, e.g., by aluminum and its alloys, steel, etc.

The at least one duct may be configured to receive and interact with the one or more soundwaves from the transformer to reduce a sound pressure level of the transformer by at least 1 dB, particularly at least 2 dB, more particularly at least 3 dB, more particularly at least 4 dB, more particularly at least 5 dB, more particularly at least 6 dB, more particularly at least 7 dB, more particularly at least 8 dB, more particularly at least 9 dB, more particularly at least 10 dB. The sound pressure level may be measured at a distance of 30 cm from an outer surface of the at least one sound-reducing element.

The present disclosure further relates to a system which includes at least one transformer and at least one device according to any of the embodiments described herein. The device may be arranged on an exterior of the transformer. The transformer may include at least one receptacle, at least one core, and at least on winding wound at least partially about the at least one core. The device may be arranged on an exterior, in particular on at least one outer surface, of the at least one receptacle.

The features, embodiments, and advantages discussed herein with respect to the device also apply to the system accordingly. The present disclosure further relates to an assembly which may include a plurality of the device (for reducing noise caused by a transformer) according to any of the embodiments described herein. The plurality of devices may be assembled to at least partially cover or at least partially enclose at least one transformer.

The features, embodiments, and advantages discussed herein with respect to the device also apply to the assembly accordingly.

One or more properties of the at least one duct of a first device of the plurality of devices may be different compared with at least one second device of the plurality of devices. In other words, the assembly may include a plurality of devices which vary in one or more properties among each other. This may allow the plurality of devices to be tailored towards different functions and/or purposes, e.g., to dampen different frequencies and/or different frequency ranges and/or to dampen frequencies over a broader frequency range and/or to provide different damping mechanisms, e.g., damping via resonance damping and interference.

The one or more properties may include one or more of: a total duct length, a cross-sectional area of the duct, one or more directions in which the duct extends, whether a medium at least partially fills the duct (e.g., one or more of the ducts may be at least partially filled with a medium, e.g., a sound-absorbing material, and one or more of the ducts may not be filled with the medium, e.g., a sound-absorbing material), a type of medium which at least partially fills the duct, a course of the duct, a number of redirections of the duct, a number of ducts, a configuration of an end of the duct, whether the duct has an open end or a closed end (e.g., one or more of the ducts may have an open end and one or more of the ducts may have a closed end), whether the duct has no closed ends or no open ends (i.e., the duct(s) of the first device may have no closed ends and the duct(s) of the second device may have no open ends) at least one frequency of the noise, in particular a dominating frequency, which the respective device is configured to dampen.

The following list of aspects provides alternative and/or further features of the disclosure:

1. A device for reducing noise caused by a transformer, including: at least one sound-reducing element including at least one duct arranged in a meandering pattern and configured to attenuate one or more soundwaves received from the transformer, the at least one sound-reducing element optionally being configured to be arranged on an exterior and/or an interior of the transformer. 2. The device according to aspect 1, wherein the at least one duct includes at least one inlet opening configured to receive one or more soundwaves from the transformer, and wherein each duct includes a closed end.

3. The device according to aspect 2, wherein each end of each duct is closed.

4. The device according to aspect 2 or 3, wherein the at least one inlet opening faces the transformer, when the at least one sound-reducing element is arranged on the exterior of the transformer.

5. The device according to any of the preceding aspects, wherein the at least one soundreducing element has a plurality of the at least one duct, wherein each duct has a total duct length, and wherein each duct has substantially the same total duct length.

6. The device according to any of aspects 2 to 4 or aspect 5, when dependent from aspect 2, wherein the at least one inlet opening has a smaller cross-sectional area than one or more downstream sections of the at least one duct.

7. The device according to any of the preceding aspects, wherein the at least one duct is tapered in an upstream direction in at least a section of the at least duct.

8. The device according to any of the preceding aspects, wherein the at least one soundreducing element has a plurality of the at least one duct, wherein each duct has a total duct length, and wherein the total duct lengths of the ducts are substantially identical or differ by no more than 30%, preferably no more than 20%, more preferably no more than 10%, preferably no more than 5%, from each other.

9. The device according to any of the preceding aspects, wherein each duct has only one open end.

10. The device according to any of the preceding aspects, wherein the transformer includes a plurality of stiffening elements configured to increase a stiffness of the transformer and/or a tank of the transformer, preferably wherein the stiffening elements are arranged on an outer surface or outward facing surface of the tank of the transformer, wherein the device and/or the at least one sound-reducing element is/are at least partially, in particular completely, arranged or arrangeable: on a side or face of the stiffening elements which faces away from the tank of the transformer and/or at a distal end of the stiffening elements; and/or between adjacent stiffening elements of the plurality of stiffening elements.

11. The device according to any of the preceding aspects, wherein the transformer includes a plurality of cooling fins configured to conduct and dissipate heat from the transformer, in particular from a tank of the transformer, to an environment, preferably wherein the cooling fins are arranged on an outer surface of the tank of the transformer, wherein device and/or the at least one sound-reducing element is/are at least partially, in particular completely, arranged or arrangeable on a side of the cooling fins which faces away from the tank of the transformer.

12. The device according to any of the preceding aspects, wherein the device and/or the at least one sound-reducing element is at least partially arranged or arrangeable in at least one cavity defined in the transformer and/or a tank of the transformer.

13. The device according to any of the preceding aspects, wherein the transformer is void of additional noise damping means and/or material.

14. The device according to any of the preceding aspects, including a plurality of the at least one sound-reducing element which are arranged as at least one wall and/or as an enclosure for at least partially, preferably completely, enclosing the transformer.

15. The device according to any of the preceding aspects, wherein the at least one duct includes at least one inlet opening which faces the transformer, when the at least one sound-reducing element is arranged on the exterior of the transformer, wherein the at least one inlet opening is configured to receive one or more soundwaves from the transformer.

16. The device according to any of the preceding aspects, wherein the at least one duct includes a closed end.

17. The device according to any of the preceding aspects, wherein the at least one soundreducing element includes a plurality of walls which at least partially define the at least one duct, in particular between opposing walls of the plurality of walls. 18. The device according to aspect 17, wherein at least some of the walls are arranged substantially parallel to each other.

19. The device according to aspect 17 or 18, further including at least one connecting device which interconnects at least two of the walls, in particular at least two opposing walls of the plurality of walls, in particular wherein the at least one connecting device is configured as a spacer.

20. The device according to aspect 19, wherein the at least one connecting device extends substantially perpendicularly from the respective walls.

21. The device according to any of the preceding aspects, wherein the at least one duct includes a plurality of duct sections which are interconnected, wherein at least some, in particular all, of the duct sections extend substantially parallel to each other.

22. The device according to aspect 21, wherein at least some, in particular all, of the duct sections are arranged such that the one or more soundwaves are redirected from an upstream duct section of the duct sections to a downstream duct section of the duct sections by at least one angle of redirection.

23. The device according to aspect 22, wherein the angle of redirection is at least 30°, particularly at least 40°, more particularly at least 50°, more particularly at least 60°, more particularly at least 70°, more particularly at least 80°, more particularly at least 90°, more particularly at least 100°, more particularly at least 110°, more particularly at least 120°, more particularly at least 130°, more particularly at least 140°, more particularly at least 150°, more particularly at least 160°, more particularly at least 170°, more particularly at least 180°.

24. The device according to any of the preceding aspects, wherein the at least one soundreducing element is configured to be coupled to at least one support structure which is configured to be arranged on the exterior of the transformer, in particular wherein the at least one support structure is configured to be coupled to an outer surface of the transformer.

25. The device according to aspect 24, wherein the at least one support structure includes a plurality of channels, wherein at least one, in particular each, of the at least one sound-reducing element is arranged at least partially, in particular completely, within a channel of the plurality of channels.

26. The device according to aspect 25, wherein a cross-section of at least a portion of at least some, in particular each, of the channels is substantially completely filled by one or more of the at least one sound-reducing element.

27. The device according to aspect 25 or 26, wherein the channels are at least partially defined by a plurality of ribs which extend away from the transformer, when the at least one support structure is arranged on the exterior of the transformer, wherein the ribs are configured to conduct and dissipate heat from the transformer to an ambient.

28. The device according to any of aspects 25 to 27, wherein the channels each include at least one channel opening which faces towards the transformer, when the at least one support structure is arranged on the exterior of the transformer, wherein the at least one channel opening is substantially closed by one or more of the at least one soundreducing element.

29. The device according to any of the preceding aspects, wherein the at least one duct is at least partially filled with at least one sound-absorbing material, in particular wherein the at least one sound-absorbing material is arranged proximate to the at least one inlet opening.

30. The device according to any of the preceding aspects, wherein a total length and/or a width of the at least one duct is sized based at least partially on at least one wavelength and/or at least one amplitude and/or at least one frequency, in particular one or more dominant frequencies of a plurality of frequencies, of the one or more soundwaves which are emitted by the transformer.

31. The device according to any of the preceding aspects, wherein a total length of the at least one duct is from 10% to 50%, in particular from 15% to 45%, in particular from 20% to 40%, in particular from 20% to 35%, in particular from 20% to 30%, in particular substantially 25%, of a wavelength of one or more soundwaves which are emitted by the transformer, in particular at least for a frequency of the one or more soundwaves of 300 Hz. 32. The device according to any of the preceding aspects, wherein the at least one soundreducing element is integrally formed.

33. The device according to any of the preceding aspects, wherein the at least one soundreducing element is made of at least one of the following materials: acrylonitrile styrene acrylate and a thermoplastic, in particular an amorphous thermoplastic.

34. The device according to any of the preceding aspects, wherein the at least one duct is configured to receive and interact with the one or more soundwaves from the transformer to reduce a sound pressure level of the transformer by at least 1 dB, particularly at least 2 dB, more particularly at least 3 dB, more particularly at least 4 dB, more particularly at least 5 dB, more particularly at least 6 dB, more particularly at least 7 dB, more particularly at least 8 dB, more particularly at least 9 dB, more particularly at least 10 dB.

35. An assembly including a plurality of the device according to any of the preceding aspects, wherein the plurality of devices are assembled to at least partially cover or at least partially enclose at least one transformer.

36. The assembly according to aspect 35, wherein one or more properties of the at least one duct of a first device of the plurality of devices are different compared with at least one second device of the plurality of devices, preferably wherein the one or more properties include one or more of: a total duct length, a cross-sectional area of the duct, one or more directions in which the duct extends, whether a medium at least partially fills the duct, a type of medium which at least partially fills the duct, a course of the duct, a number of redirections of the duct, a number of ducts, a configuration of an end of the duct, whether the duct has an open end or a closed end, whether the duct has no closed ends or no open ends, at least one frequency of the noise, in particular a dominating frequency, which the respective device is configured to dampen.

37. An enclosure configured to at least partially, preferably completely, enclose a transformer to reduce noise caused by the transformer, wherein the enclosure is comprised of or including a plurality of the device according to any of aspects 1 to 34.

38. A system including at least one transformer and at least one device according to any of aspects 1 to 34 and/or at least one assembly according to aspect 35 or 36 and/or at least one enclosure according to aspect 37 which is/are arranged on an exterior of the at least one transformer.

Fig. 1 schematically shows, in a top view, a device 10 for reducing noise caused by a transformer 12. For clarity purposes, not all of the elements shown in Fig. 1 are provided with reference signs, in particular when a plurality of the respective element are shown in Fig 1. The device 10 may include at least one support structure 14 configured to be arranged on an exterior of the transformer 12. The at least one support structure 14 may be mounted on an outer surface of the transformer 12, as shown in Fig. 1, or may be arranged at a distance from the transformer 12. Though only a single device 10 is shown in Fig. 1, a plurality of devices 10 may be provided. For instance, one or more devices 10 may be provided on a plurality, in particular all, sides of the transformer 12.

The device 10 may further include at least one sound-reducing element 16 configured for reducing noised caused/generated by the transformer 12. The at least one sound-reducing element 16 may be arranged at least partially within the at least one support structure 14. The at least one sound-reducing element 16 may be integrally formed. Alternatively, the at least one sound-reducing element 16 may be assembled from a plurality of components. Alternatively, the at least one support structure 14 may be omitted. For instance, the at least one sound-reducing element 16 may be mounted, e.g., directly, to at least one surface, preferably at least one external surface and/or at least one internal surface, of the transformer 12.

The at least one sound-reducing element 16 may include at least one duct 18. The at least one duct 18 may be arranged in a meandering pattern. The at least one duct 18 may be configured to receive one or more soundwaves from the transformer 12 to reduce noise caused by the transformer 12.

The device 10 may be used with any type of transformer to reduce noise caused by the respective transformer. For instance, the transformer 12 may be a liquid-immersed transformer, a dry-type transformer, or any other type of transformer. Thus, the device 10 disclosed herein is not limited to an application with one or more specific types of transformers. In general, the transformer 12 may include at least one receptacle or casing 20, at least one core 22, and at least one winding 24 wound at least partially about the at least one core 22. The device 10 may be mounted to the receptacle or casing 20, in particular to an outer surface thereof. The at least one duct 18 may include at least one inlet opening 26 which faces the transformer 12, when the at least one support structure 14 is arranged on the exterior of the transformer 12. The at least one inlet opening 26 may be configured to receive one or more soundwaves from the transformer 12. The at least one duct 18 may include a closed end 28. The at least one sound-reducing element 16 may include a plurality of walls 30 which at least partially define the at least one duct 18, in particular between opposing walls 32 of the plurality of walls 30.

The device 10 may further include at least one connecting device 33 which interconnects at least two of the walls 30, in particular at least two opposing walls 32 of the plurality of walls 30. The at least one connecting device 33 may be configured as a spacer. The at least one connecting device 33 may be a solid piece of material. The at least one connecting device 33 is indicated in Fig. 1 as a dashed line to illustrate that the at least one connecting device 33 does not block the at least one duct 18 at the location of the at least one connecting device 33. Instead, the at least one connecting device 33 permits the one or more soundwaves and other media, such as air, to travel past the at least one connecting device 33, e.g., above and/or below, i.e., behind and/or in front of the drawing plane in Fig. 1, the at least one connecting device 33.

The at least one duct 18 may include a plurality of duct sections 34 which are interconnected. At least some, in particular all, of the duct sections 34 may extend substantially parallel to each other.

At least some, in particular all, of the duct sections 34 may be arranged such that the one or more soundwaves are redirected from an upstream duct section of the duct sections 34 to a downstream duct section of the duct sections 34 by at least one angle of redirection. As shown in Fig. 1, the angle of redirection may be substantially 180°. However, such an angle of redirection is only an exemplary configuration and may alternatively be a number of different values. In particular, the angle of redirection may be at least 30°, particularly at least 40°, more particularly at least 50°, more particularly at least 60°, more particularly at least 70°, more particularly at least 80°, more particularly at least 90°, more particularly at least 100°, more particularly at least 110°, more particularly at least 120°, more particularly at least 130°, more particularly at least 140°, more particularly at least 150°, more particularly at least 160°, more particularly at least 170°, more particularly at least 180°. The at least one support structure 14 may include a plurality of channels 36. At least one, in particular each, of the at least one sound-reducing element 16 may be arranged at last partially, in particular completely, within a channel 36 of the plurality of channels 36.

A cross-section of at least a portion of at least some, in particular each, of the channels 36 may be substantially completely filled by one or more of the at least one sound-reducing element 16. The channels 36 may be at least partially defined by a plurality of ribs 40 which extend away from the transformer 12, when the at least one support structure 14 is arranged on the exterior of the transformer 12 in an operative state. The ribs 40 may be configured to conduct and dissipate heat from the transformer 12 to an ambient.

The at least one duct 18 may be at least partially filled with at least one sound-absorbing material. The at least one sound-absorbing material may be arranged proximate to the at least one inlet opening 26.

A total length and/or a width of the at least one duct 18 may be sized based at least partially on at least one wavelength, in particular one or more dominant frequencies of a plurality of frequencies, of the one or more soundwaves which are emitted by the transformer 12.

The orientation of the at least one sound-reducing element 16 shown in Fig. 1 is only exemplary. For instance, the at least one sound-reducing element 16 may be rotated, e.g., by 90°, compared with the orientation of the at least one sound-reducing element 16 shown in Fig. 1.

Figs. 2 and 3 show diagrams of a pressure distribution and a particle velocity distribution, respectively, in the at least one duct 18 of the at least one sound-reducing element 16. As can be seen in the diagram of Fig. 2, an acoustic pressure within the at least one duct 18 may increase further into the at least one duct 18. As can be seen in the diagram of Fig. 3, a particle velocity within the at least one duct 18 may be reduced further into the at least one duct 18, which may at least contribute to reducing noise caused by a transformer. For the results shown in Figs. 2 and 3, a sound-absorbing material was arranged at the at least one inlet opening 26.

Figs. 4 to 6 show various arrangements of the device 10.

As shown in Fig. 4, the transformer 12 may include a plurality of cooling fins 46 configured to conduct and dissipate heat from the transformer 12, e.g., from a tank 48 of the transformer 12, to an environment. The cooling fins 46 may be arranged on an outer surface 50 of the tank 48 of the transformer 12.

The device 10, more specifically the at least one sound-reducing element 16, may be arranged or arrangeable on a side 52 of the cooling fins 46 which faces away from the tank 48 of the transformer 12. The device 10, more specifically the at least one sound-reducing element 16, may be at least partially in contact, i.e., touching, the cooling fins 46. Alternatively, the device 10, more specifically the at least one sound-reducing element 16, may be distanced, i.e., arranged at a distance greater than zero, from the cooling fins 46.

As shown in Figs. 5 and 6, the transformer 12 may include a plurality of stiffening elements 54 configured to increase a stiffness of the transformer 12 and/or the tank 48 of the transformer 12. The stiffening elements 54 may be configured as stiffening ribs.

The stiffening elements 54 may be arranged on an outer surface or outward facing surface 56 of the tank 48 of the transformer 12. The stiffening elements 54 may protrude, preferably in a radial direction, from the outer surface or outward facing surface 56. The stiffening elements 54 may be configured integrally and/or monolithically with the outer surface 56. The stiffening elements 54 may be elongate and/or may extend in a longitudinal direction of the transformer 12 and/or substantially parallel to a longitudinal axis of the transformer 12 and/or the tank 48 of the transformer 12.

As shown in Fig. 5, the device 10, more specifically the at least one sound-reducing element 16, may be at least partially, in particular completely, arranged or arrangeable on a side or face 58 of the stiffening elements 54 which faces away from the tank 48 of the transformer 12 and/or at a distal end of the stiffening elements 54.

As further shown in Fig. 5, one or more radiating devices 60 may be provided. The radiating devices 60 may include one or more cooling fins 62 configured to conduct and dissipate heat, e.g., from the transformer 12, e.g., from the tank 48 of the transformer 12, to an environment. The one or more radiating devices 60 may be components of the transformer 12. The device 10, more specifically the at least one sound-reducing element 16, may be at least partially, in particular completely, arranged between the stiffening elements 54, more specifically the side or face 58 of the stiffening elements 54, and the radiating devices 60.

Alternatively, or additionally, the device 10, more specifically the at least one sound-reducing element 16, may be at least partially, in particular completely, arranged or arrangeable between adjacent stiffening elements 54 of the plurality of stiffening elements 54 (as shown in Fig. 6 in exemplary manner). In other words, the device 10, more specifically the at least one sound-reducing element 16, may be arranged in one or more spaces or cavities 64 arranged between and/or at least partially defined by adjacent stiffening elements 54. The one or more spaces 64 may already exist and/or be provided in existing transformers. Hence, the device 10, more specifically the at least one sound-reducing element 16, may be arranged at least partially in one or more spaces which would otherwise be empty and thus unused. This may provide a relatively space-efficient and/or compact arrangement. Fig. 7 shows an enclosure 70 configured to at least partially, preferably completely, enclose the transformer 12. The enclosure 70 may be comprised of or may include a plurality of the device 10. The enclosure 70 may enclose the transformer 12 at least along all lateral sides of the transformer 12. Optionally, a top or top side of the transformer 12 may not be enclosed or covered by the enclosure 70. The enclosure 70 may also be referred to as an assembly.

Claims

1. A device (10) for reducing noise caused by a transformer (12), including: at least one sound-reducing element (16) configured to be arranged on an exterior of the transformer (12) and including at least one duct (18) arranged in a meandering pattern and configured to attenuate one or more soundwaves received from the transformer (12).

2. The device (10) according to claim 1, wherein the at least one duct (18) includes at least one inlet opening (26) configured to receive one or more soundwaves from the transformer (12), and wherein each duct (18) includes a closed end (28).

3. The device (10) according to claim 2, wherein each end (28) of each duct (18) is closed.

4. The device (10) according to claim 2 or 3, wherein the at least one inlet opening (26) faces the transformer (12), when the at least one sound-reducing element (16) is arranged on the exterior of the transformer (12).

5. The device (10) according to any of the preceding claims, wherein the at least one sound-reducing element (16) has a plurality of the at least one duct (18), wherein each duct (18) has a total duct length, and wherein each duct (18) has substantially the same total duct length.

6. The device (10) according to any of claims 2 to 4 or claim 5, when dependent from claim 2, wherein the at least one inlet opening (26) has a smaller cross-sectional area than one or more downstream sections of the at least one duct (18).

7. The device (10) according to any of the preceding claims, wherein the at least one duct (18) is tapered in an upstream direction in at least a section of the at least duct (18).

8. The device (10) according to any of the preceding claims, wherein the at least one sound-reducing element (16) has a plurality of the at least one duct (18), wherein each duct (18) has a total duct length, and wherein the total duct lengths of the ducts (18) are substantially identical or differ by no more than 30%, preferably no more than 20%, more preferably no more than 10%, preferably no more than 5%, from each other.

9. The device (10) according to any of the preceding claims, wherein each duct (18) has only one open end.

10. The device (10) according to any of the preceding claims, wherein the transformer (12) includes a plurality of stiffening elements (54) configured to increase a stiffness of the transformer (12) and/or a tank (48) of the transformer (12), preferably wherein the stiffening elements (54) are arranged on an outer surface or outward facing surface (56) of the tank (48) of the transformer (12), wherein the device (10) and/or the at least one sound-reducing element (16) is/are at least partially, in particular completely, arranged or arrangeable: on a side or face (58) of the stiffening elements (54) which faces away from the tank (48) of the transformer (12) and/or at a distal end of the stiffening elements (54); and/or between adjacent stiffening elements (54) of the plurality of stiffening elements (54).

11. The device (10) according to any of the preceding claims, wherein the transformer (12) includes a plurality of cooling fins (46) configured to conduct and dissipate heat from the transformer (12), in particular from a tank (48) of the transformer (12), to an environment, preferably wherein the cooling fins (46) are arranged on an outer surface (50) of the tank (48) of the transformer (12), wherein device (10) and/or the at least one sound-reducing element (16) is/are at least partially, in particular completely, arranged or arrangeable on a side (52) of the cooling fins (46) which faces away from the tank (48) of the transformer (12).

12. The device (10) according to any of the preceding claims, wherein the device (10) and/or the at least one sound-reducing element (16) is at least partially arranged or arrangeable in at least one cavity (64) defined in the transformer (12) and/or a tank (48) of the transformer (12).

13. The device (10) according to any of the preceding claims, wherein the transformer (12) is void of additional noise damping means and/or material.

14. The device (10) according to any of the preceding claims, including a plurality of the at least one sound-reducing element (16) which are arranged as at least one wall and/or as an enclosure for at least partially, preferably completely, enclosing the transformer (12).

15. The device (10) according to any of the preceding claims, wherein the at least one sound-reducing element (16) includes a plurality of walls (30) which at least partially define the at least one duct (18), in particular between opposing walls (32) of the plurality of walls (30).

16. The device (10) according to any of the preceding claims, wherein the at least one duct (18) includes a plurality of duct sections (34) which are interconnected, wherein at least some, in particular all, of the duct sections (34) extend substantially parallel to each other.

17. The device (10) according to claim 16, wherein at least some, in particular all, of the duct sections (34) are arranged such that the one or more soundwaves are redirected from an upstream duct section of the duct sections (34) to a downstream duct section of the duct sections (34) by at least one angle of redirection.

18. The device (10) according to claim 17, wherein the angle of redirection is at least 30°, particularly at least 40°, more particularly at least 50°, more particularly at least 60°, more particularly at least 70°, more particularly at least 80°, more particularly at least 90°, more particularly at least 100°, more particularly at least 110°, more particularly at least 120°, more particularly at least 130°, more particularly at least 140°, more particularly at least 150°, more particularly at least 160°, more particularly at least 170°, more particularly at least 180°.

19. The device (10) according to any of the preceding claims, wherein the at least one sound-reducing element (16) is configured to be coupled to at least one support structure (14) which is configured to be arranged on the exterior of the transformer, in particular wherein the at least one support structure (14) is configured to be coupled to an outer surface of the transformer.

20. The device according to claim 19, wherein the at least one support structure (14) includes a plurality of channels (36), wherein at least one, in particular each, of the at least one sound-reducing element (16) is arranged at least partially, in particular completely, within a channel (36) of the plurality of channels (36).

21. The device (10) according to claim 20, wherein a cross-section of at least a portion of at least some, in particular each, of the channels (36) is substantially completely filled by one or more of the at least one sound-reducing element (16), in particular wherein the channels (36) are at least partially defined by a plurality of ribs (40) which extend away from the transformer (12), when the at least one support structure (14) is arranged on the exterior of the transformer (12), in particular wherein the ribs (40) are configured to conduct and dissipate heat from the transformer (12) to an ambient.

22. The device (10) according to any of the preceding claims, wherein the at least one duct (18) is at least partially filled with at least one sound-absorbing material, in particular wherein the at least one sound-absorbing material is arranged proximate to the at least one inlet opening (26).

23. The device (10) according to any of the preceding claims, wherein a total length and/or a width of the at least one duct (18) is sized based at least partially on at least one frequency, in particular one or more dominant frequencies of a plurality of frequencies, of the one or more soundwaves which are emitted by the transformer (12).

24. The device (10) according to any of the preceding claims, wherein a total length of the at least one duct (18) is from 10% to 50%, in particular from 15% to 45%, in particular from 20% to 40%, in particular from 20% to 35%, in particular from 20% to 30%, in particular substantially 25%, of a wavelength of one or more soundwaves which are emitted by the transformer (12), in particular at least for a frequency of the one or more soundwaves of 300 Hz.

25. The device (10) according to any of the preceding claims, wherein the at least one sound-reducing element (16) is integrally formed.

26. An assembly (70) including a plurality of the device (10) according to any of the preceding claims, wherein the plurality of devices (10) are assembled to at least partially cover or at least partially enclose at least one transformer (12).

27. The assembly (70) according to claim 26, wherein one or more properties of the at least one duct (18) of a first device (10) of the plurality of devices (10) are different compared with at least one second device (10) of the plurality of devices (10), preferably wherein the one or more properties include one or more of: a total duct length, a cross-sectional area of the duct (18), one or more directions in which the duct (18) extends, whether a medium at least partially fills the duct (18), a type of medium which at least partially fills the duct (18), a course of the duct (18), a number of redirections of the duct (18), a number of ducts (18), a configuration of an end of the duct (18), whether the duct (18) has an open end or a closed end, whether the duct (18) has no closed ends or no open ends, at least one frequency of the noise, in particular a dominating frequency, which the respective device (10) is configured to dampen.

28. An enclosure (70) configured to at least partially, preferably completely, enclose a transformer (12) to reduce noise caused by the transformer (12), wherein the enclosure (70) is comprised of or includes a plurality of the device (10) according to any of claims 1 to 25.

29. A system including at least one transformer (12) and at least one device (10) according to any of claims 1 to 25 and/or at least one assembly (70) according to claim 26 or 27 and/or at least one enclosure (70) according to claim 28 which is/are arranged on an exterior of the at least one transformer (12).