Transformer device

Abstract

The present disclosure relates to a transformer arrangement (100) comprising a transformer (10) comprising at least one phase winding (12). The phase winding (12) has coil turns around a coil axis (c). The transformer arrangement (100) further comprises a transformer tank (20) having walls (22) forming a housing in which the transformer (10) is arranged. The housing contains an incompressible medium in which the transformer (10) is submerged. A partition plate (30) is arranged in the transformer tank (20) between a wall (22) of the transformer tank (20) and at least one phase winding (12) of the transformer (10). The bulkhead (30) has an inner surface facing the transformer and an outer surface facing the wall. The separator plate (30) is also arranged at a distance from at least one phase winding (12) of the transformer (10). The transformer (10) has lateral sides parallel to the coil axis (c). The bulkhead (30) has at least one lateral portion (32) aligned with a lateral side of the transformer (10), and wherein the at least one lateral portion (32) of the bulkhead surrounds the transformer (30).

Description

Technical Field

[0001] The present disclosure relates to a transformer device for reducing load noise. Background Art

[0002] Transformers must meet various noise level requirements. Immersed in electrical insulating oil within the transformer tank, transformers vibrate during operation. Vibrations are transmitted from the transformer windings through the oil to the tank walls, causing significant vibrational displacement of the walls and, in turn, noise. Three main noise sources can be identified in transformers: no-load noise or core noise caused by magnetostriction; loaded noise caused by electromagnetic forces in the windings; and noise from auxiliary equipment such as fans and pumps used in the cooling system. Of these three, loaded noise contributes significantly to the overall noise, especially in large units.

[0003] Current noise reduction solutions are ineffective, costly, and typically applied far from the source and primary transmission path of load noise. Traditional solutions, such as acoustic panels and damping layers attached to the outside of the enclosure walls, are often bulky and impractical. Sand-filled enclosure components are another low-noise solution, but they primarily address core noise and have limited impact on load noise. Due to the complex vibration and radiation characteristics of enclosed transformer enclosures, traditional solutions are difficult to optimize and standardize for routine, off-the-shelf design work. Sometimes, significant variations can occur between units.

[0004] According to its abstract, WO0101425 relates to a sound insulation device for a stationary induction motor having an active part, an insulating fluid surrounding the active part, and a box enclosing the insulating fluid. The sound insulation device comprises a gas-filled cavity and an elastic membrane surrounding the gas-filled cavity, thereby obtaining a highly compressible sound insulation device. In the induction motor, the device is arranged between the active part and the box of the induction motor and is spaced apart from the interior of the box. The sound insulation device preferably extends in one plane, whereby the device comprises a membrane portion facing the active part and a membrane portion facing the box. Preferably, at least one membrane portion has at least one corrugated area, and the spacing membrane is arranged in the cavity and contacts the membrane portion at at least two points.

[0005] According to its abstract, JPH10106854 relates to a stationary induction electrical equipment system that reduces noise even in compact equipment configurations. A resonance-type muffler with a partially formed internal cavity opening is provided on the inner surface of the housing. Because the muffler is set to a frequency that resonates with the noise generated within the housing, it can reduce noise within the housing by resonating with the noise frequency. Consequently, noise radiated from the housing to the outside is reduced.

[0006] According to its abstract, CN201732653 relates to a soundproof oil tank structure for a transformer, comprising an oil tank body, the inner wall of which is provided with a composite damping steel plate. When a magnetic shield is provided on the inner wall of the oil tank body, two layers of composite damping steel plates are provided on the inner and outer sides of the magnetic shield, respectively, and are compressed by the magnetic shield's clamping plates. When the inner wall of the oil tank body is not provided with a magnetic shield, the composite damping steel plates are fixed to the inner wall of the oil tank body via mounting brackets. Arranging the composite damping steel plates on the inner wall of the transformer oil tank body effectively reduces the noise of the transformer body. The soundproof oil tank structure of the transformer is simple and easy to manufacture and install.

[0007] According to its abstract, CN105810419 relates to a noise reduction device for a transformer, a transformer tank, and a transformer. The device comprises a noise reduction plate and an insulating layer covering the surface of the plate. The plate comprises at least two cardboard layers and a metal plate layer disposed between adjacent cardboard layers. Furthermore, both the top and bottom layers of the plate are cardboard layers. The device offers the advantages of low cost and excellent noise reduction. Furthermore, the device can be placed in the vacant space within the transformer tank, eliminating the need for wiring and increasing the size of the transformer. Furthermore, the transformer's straight inner wall simplifies the structure of the device, making it easy to process and industrialize.

[0008] According to its abstract, EP0073401 relates to shielding walls supported on the tank side walls by means of a large-area compressible intermediate layer, which at the same time represents a thermal insulation wall for reducing noise emissions, since the natural frequency of the vibration system is less than 0.7 times the power frequency, the vibration system being in each case composed of the portion of the shielding wall located between the attachment point and the relevant portion of the intermediate layer. The use of such a device is particularly economical and applicable in high-power transformers.

[0009] According to its abstract, JP2017011140 relates to a transformer capable of reducing noise by improving the fixing method for the magnetic shield provided within the transformer case. The transformer comprises: an iron core having core legs and a core yoke; windings wound around the core legs; a case containing the core and windings; and a magnetic shield provided within the case opposite the windings. After a seat is fixed to the inner surface of the case, a buffer member is placed on the seat, and the magnetic shield is secured to the buffer member.

[0010] US 3,175,173 relates to a device for reducing audible noise generated by an electrical device during normal operation, and more particularly to a noise reduction device for an electric induction device of the type having a magnetic flux generating member contained in a metal housing.

[0011] According to its abstract, US Pat. No. 4,373,608 relates to a tuned sound barrier for machines that radiate sound primarily at a few constant, discrete frequencies, comprising an array of mechanical resonators distributed across the surface of the barrier. Each resonator in the array is tuned to present a high mechanical impedance to the transmission of mechanical vibrations at one of the discrete frequencies emitted by the source machine. The tuned sound barrier can be a freestanding sound barrier or an attachment to the machine enclosure.

[0012] According to its abstract, WO2008080820 relates to an oil-immersed power transformer / reactor comprising a transformer / reactor core and windings housed in a housing comprising a base plate, walls, and a foundation supporting the housing. An elongated continuous strip forming an enclosed frame is disposed between the base plate and the foundation, with the outer periphery of the base plate extending beyond the inner periphery of the frame, thereby enclosing an air volume within the frame, base plate, and foundation. The housing and support reduce acoustic noise emitted by the transformer / reactor.

[0013] According to its abstract, SE1651719 relates to a solution for attenuating low-frequency sound around electric motors. The overall approach is to enclose the machine with walls of sufficient quality without increasing costs. The first aspect of this invention, which utilizes sand-filled panels, is to effectively reduce low-frequency noise, particularly at 100Hz and 120Hz. This corresponds to the load noise of mainstream AC transformers and the sound generated by Maxwell forces in shunt reactors. Summary of the Invention

[0014] Therefore, it is an object of the present disclosure to provide an improved transformer arrangement which exhibits reduced noise radiation. More specifically, it is an object of the present disclosure to provide a transformer arrangement which is capable of reducing load noise.

[0015] According to a primary aspect of the present disclosure, this objective is achieved by a transformer device comprising a transformer including at least one phase winding. The phase winding has coil turns arranged around a coil axis. The transformer device further comprises a transformer case having walls forming a housing, wherein the transformer is disposed within the housing. The housing contains an incompressible medium in which the transformer is immersed. A partition is disposed within the transformer case, the partition being located between the wall of the transformer case and the at least one phase winding of the transformer. The partition has an inner surface facing the transformer and an outer surface facing the wall. The partition is also spaced apart from the at least one phase winding of the transformer. The transformer has a first portion extending along a first axis parallel to the coil axis, a second portion extending along a second axis, and a third portion extending along a third axis, wherein the first, second, and third axes are perpendicular to each other. The transformer has lateral sides parallel to the coil axis, and the partition has at least one lateral portion aligned with the lateral side of the transformer, wherein the at least one lateral portion of the partition surrounds the transformer along a plane transverse to the coil axis.

[0016] The lateral portion of the partition is not limited to being aligned parallel to the lateral sides of the transformer. The lateral portion may be tilted relative to the coil axis.

[0017] From the perspective of reducing load noise, it is ideal for the partition to completely surround the transformer without any openings. However, in practice, design considerations dictate that the incompressible medium can flow relatively freely around at least one phase winding for cooling purposes. Furthermore, the partition requires a large number of electrical connections between the transformer and the exterior of the transformer tank. Therefore, a partition configuration in which the lateral portion of the partition surrounds or encloses a lateral side of the transformer or at least one phase winding is considered the preferred configuration.

[0018] Research has shown that the primary mechanism by which the oil mechanically excites the tank walls is related, on the one hand, to the oil's incompressibility and, on the other, its inertia. The acoustic incompressibility of the oil means that any volume change induced by winding vibrations will inevitably translate into an equivalent volume change in the tank. The net volume change of the tank is, in turn, achieved through the tank's structural modes, which are organized in such a way as to create a net volume change. At low frequencies, this net volume change can be considered the result of a so-called monopole tank velocity distribution, and this global distribution is known to have such high radiation efficiency that it can mask the noise contributions of other local tank modal noise contributions. The latter, sometimes referred to as a volume-preserving local dipole distribution, has a much lower radiation efficiency than the global monopole distribution.

[0019] The fact that the entire oil volume can be considered acoustically incompressible also means that its inertia plays a significant role, as this volume is nothing more than a large acoustically reactive near field. This means that the oil excites the tank through its inertial forces rather than through compressibility-induced pressure. An incompressible medium is one whose volume or density does not change with pressure. True incompressibility exists only in theory. However, the term "incompressible" is used in this disclosure to refer to a medium that is nearly incompressible within the frequency range of interest. In this disclosure, the medium can be an electrically insulating medium, such as mineral oil.

[0020] Typically, one approach to mitigating noise radiation from transformer tank walls is to insert a barrier between the windings and the tank wall to protect the tank wall from the inertial forces of the incompressible medium. In the disclosed transformer arrangement, a noise-reducing baffle is positioned between the transformer and the transformer tank wall, spaced apart from at least one phase winding. Thus, the baffle is isolated from direct structural vibrations of the source (i.e., the transformer / phase winding) and is configured to block the inertia of the incompressible medium emanating from the phase winding, thereby reducing vibrations at the tank wall.

[0021] Optionally, the baffle is configured to have no structural resonance at twice the network frequency.

[0022] The mains frequency is the frequency at which the transformer operates, which results in mechanical vibrations at twice the mains frequency. The mains frequency is typically 50 Hz or 60 Hz. For example, the separator is configured to have no structural resonance at 100 Hz and / or 120 Hz. Preferably, the separator is configured to have no structural resonance in a range of up to six times the mains frequency.

[0023] Therefore, a stiff (ideally, rigid) partition is arranged as a barrier between the winding and the tank. Rigidity means that the partition is configured to exhibit a structural resonance far exceeding twice the network frequency, and the residual average static deflection of the partition due to the oscillating inertial forces of the surrounding incompressible medium is much smaller than the average particle displacement of the medium. Therefore, the inertial forces of the incompressible medium are not transmitted beyond the partition, or at least are significantly reduced beyond the partition.

[0024] Optionally, the inner surface of the diaphragm includes a volumetrically compressible lining.

[0025] Under the influence of electromagnetic forces acting on the transformer's structural components, these components change both in shape and volume. The latter, exerted on an incompressible medium, causes the box to vibrate to produce the same volume change, resulting in a net volume change of the air surrounding the box, which in turn leads to higher noise levels compared to the case where the net volume change of the box is zero. It is proposed here that this zero net volume change of the box is caused by the volume-compressible lining, which (rather than the box) absorbs the volume change of the transformer's structural components. The remaining inertial forces are blocked and reduced by the rigid parts of the partition.

[0026] The bulk modulus of the lining should be significantly smaller than the bulk modulus of the surrounding incompressible medium. The bulk modulus describes the elastic properties of a solid or fluid when pressure is applied on all surfaces. Bulk modulus, sometimes referred to as incompressibility, is a measure of a substance's ability to undergo a change in volume when compressed on all sides. For example, the bulk modulus of electrical insulating transformer oil is approximately 1.7 GPa. However, the lining preferably has a low bulk modulus, such as approximately 0.1-0.2 GPa, or even less.

[0027] Optionally, the separator comprises a granular material.

[0028] Energy propagation in an acoustic medium can typically be attenuated and redirected by introducing changes in impedance experienced by particle motion in the medium. The present disclosure achieves this change in impedance by introducing a bulk substance in the form of a granular compound, thereby providing an inelastic and highly damped barrier without inherent resonance.

[0029] As an alternative to rigid separators and rigid separators comprising a volume compressible liner, the separators may comprise granular material. The separators may be configured as a plurality of pockets comprising granular material, such as sand. The granular material should be heavier than the incompressible medium. For example, in electrical insulating transformers, the density of oil is approximately 870 kg / m 3 In this case, the density of the granular material can exceed 870 kg / m 3 , preferably at least 1600 kg / m 3 .

[0030] Alternatively, the partition may be arranged on the wall of the transformer tank. Thus, the partition comprising the granular material may be arranged on the inner side of the wall of the transformer tank. Thus, the bag or sack containing the granular material may be attached to the wall by conventional fixing means, preferably covering the wall.

[0031] Optionally, the partition is spaced apart from the walls of the transformer tank. Any of the aforementioned rigid, composite, or heavy / soft partitions can be placed in the transformer tank, maintaining a certain distance from at least one phase winding of the transformer and the tank walls. In this manner, the partition is not in direct mechanical contact with either the phase winding or the tank walls. This prevents mechanical vibrations from being directly transmitted from at least one phase winding to the partition, and from being directly transmitted from the partition to the tank walls.

[0032] Optionally, at any point of the partition, the distance between said point of the partition and the nearest part of at least one phase winding of the transformer is smaller than the distance between said point of the partition and the nearest part of the wall of the transformer tank.

[0033] Acoustically, it is advantageous that the diaphragm is arranged as close as possible to the vibration source in order to effectively block most of the inertial forces generated by the transformer during operation.

[0034] Optionally, the transformer has a first end along a first axis and an opposite second end along the first axis. The transformer tank further has a first wall adjacent to the first end of the transformer and extending transverse to the first axis, and an opposite second wall adjacent to the second end of the transformer and extending transverse to the first axis. The partition has at least one first portion and at least one second portion, each portion extending transverse to the first axis, wherein the at least one first portion is disposed between the first end of the transformer and the first wall of the transformer tank, and the at least one second portion is disposed between the second end of the transformer and the second wall of the transformer tank.

[0035] For the purposes of this disclosure, a transformer is defined as having a height equal to the height of at least one phase winding. Furthermore, the height of at least one phase winding is defined as the thickness of the platen including each end of the at least one phase winding. The term "height" is not limited to a vertical extension. Rather, it refers to an extension generally along the coil axis.

[0036] To cover a larger portion of the transmission path of vibrations from the source, the partition can have a first portion and a second portion in addition to the lateral portion. The first and second portions can be configured to block the inertial forces of the incompressible medium at the first and second ends of the transformer. In some transformer applications, space along the lateral sides of the transformer is limited. In such cases, the first and second portions of the partition can still be placed at the ends of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Other objects, advantages, and features of the present disclosure will become apparent from the following description of one or more embodiments with reference to the accompanying drawings, in which:

[0038] Figure 1 A perspective view of an exemplary embodiment of the present disclosure is shown.

[0039] Figure 2 A perspective view of an exemplary embodiment of the present disclosure is shown.

[0040] Figure 3 A perspective view of an exemplary embodiment of the present disclosure is shown.

[0041] Figure 4 A perspective view of a separator according to an exemplary embodiment of the present disclosure is shown.

[0042] Figure 5 A perspective view of an exemplary embodiment of the present disclosure is shown.

[0043] Figure 6 A top view of a separator according to an exemplary embodiment of the present disclosure is shown.

[0044] Figure 7 Shown is a perspective detail of a separator according to an exemplary embodiment of the present disclosure.

[0045] Figure 8 Simulation results of an exemplary embodiment of the present disclosure are shown. DETAILED DESCRIPTION

[0046] The present disclosure is developed in more detail below with reference to the accompanying drawings which illustrate examples of embodiments. The present disclosure should not be considered as being limited to the examples of embodiments described. Throughout the description, like numbers represent like elements.

[0047] Figure 1A transformer arrangement 100 is shown, including a transformer 10 having at least one phase winding 12. The transformer 10 shown has three phase windings 12. Each phase winding 12 has coil turns arranged around a coil axis c. The transformer arrangement 100 also includes a transformer tank 20 having walls 22 forming a housing, within which the transformer 10 is disposed. In the illustrated example, the transformer tank 20 is shown open to the viewer, exposing the interior of the transformer 10. In actual use, the transformer tank is typically enclosed on all sides. The housing contains an incompressible medium, within which the transformer 10 is immersed. A partition 30 is disposed within the transformer tank 20, between the wall 22 of the transformer tank 20 and the at least one phase winding 12 of the transformer 10. The partition 30 has an inner surface facing the transformer and an outer surface facing the wall. The partition 30 is spaced apart from the at least one phase winding 12 of the transformer 10. In other words, the partition does not come into direct mechanical contact with any phase winding 12 of the transformer 10. Thus, the partition is isolated from direct structural vibrations of at least one phase winding, which are generated during transformer operation. Partition 30 is configured to block the inertial force of the incompressible medium emanating from phase winding 12, thereby reducing the vibration of the incompressible medium at tank wall 22. Consequently, the displacement of tank wall 22 due to the movement of the incompressible medium is also reduced, which in turn leads to a reduction in load noise radiated by tank wall 22.

[0048] The transformer operates at a given network frequency. Typically, the network frequency is 50 Hz or 60 Hz, which causes structural vibration of at least one phase winding 12 at twice the network frequency (i.e., 100 Hz or 120 Hz, respectively). The separator 30 can be configured to have no structural resonance at twice the network frequency. Preferably, the separator 30 is configured to have no structural resonance within a range of up to six times the network frequency. Therefore, the separator 30 is not significantly excited by vibrations transmitted to the separator 30 from at least one phase winding 12 through the incompressible medium.

[0049] Alternatively, as Figure 6 As shown, the inner surface of the separator 30 may include a bulk compressible lining 34. The bulk modulus of the lining should be significantly lower than the bulk modulus of the surrounding incompressible medium. For example, the bulk modulus of electrical insulating transformer oil is approximately 1.7 GPa. However, preferably, the bulk modulus of the lining is less than 1.7 GPa, preferably 0.1-0.2 GPa, or even lower.

[0050] Alternatively, the separator 30 may comprise a granular material (rather than being rigid), such as a heavy mass that has no rigidity but has significant inherent damping. The separator may be configured as a plurality of pockets 38, such as Figure 7 As shown, these bags 38 contain granular material, such as sand. Figure 7The exemplary embodiment of FIG. 1 shows only a portion of the partition 30. As in the other embodiments, the partition 30 is intended to surround the transformer 10. The granular material should be heavy relative to the incompressible medium. For example, the density of the oil in the electrical insulating transformer is about 870 kg / m 3 In this case, the density of the granular material should preferably be higher than 870 kg / m 3 , preferably at least 1600 kg / m 3 .

[0051] Such a partition 30 comprising granular material can be arranged on the wall 22 of the transformer tank. Thus, the partition 30 comprising granular material can be arranged on the inner side of the wall 22 of the transformer tank. Thus, the bag 38 comprising granular material can be attached to the wall 22 by conventional fixing means, preferably completely covering the wall 22.

[0052] In addition to being spaced apart from at least one phase winding 12 of the transformer 10, the partition 30 may also be spaced apart from the wall 22 of the transformer tank 20. Any of the aforementioned rigid partitions, composite partitions, or granular partitions may be disposed within the transformer tank 20, spaced apart from both the at least one phase winding 12 of the transformer 10 and the tank wall 22. The partition 30 comprising granular material may be spaced apart from the tank wall 22 using a support structure (not shown) for suspending a bag 38 comprising the granular material in an incompressible medium.

[0053] The transformer 10 may have a first extension along a first axis z parallel to the coil axis c, a second extension along a second axis x, and a third extension along a third axis y. The first axis, the second axis, and the third axis are perpendicular to each other. The transformer 10 has lateral sides parallel to the coil axis c.

[0054] The partition 30 may have at least one transverse portion 32 aligned with a lateral side of the transformer 10. The at least one transverse portion 32 of the partition 30 surrounds the transformer 10. The at least one transverse portion may have a height h along the first axis z. The height h of the at least one transverse portion 32 may be equal to the height H of the at least one phase winding 12. In the case of multiple transverse portions 32, the sum of the heights h of the individual transverse portions may be equal to or less than the height H of the at least one phase winding 12. To cool the at least one phase winding 32, the sum of the heights h of the individual transverse portions is preferably less than the height H of the at least one phase winding 12.

[0055] The transformer 10 may have a first end along a first axis z and an opposite second end along the first axis z. The transformer tank 20 also has a first wall 22' extending transverse to the first axis z and an opposite second wall 22" extending transverse to the first axis z.

[0056] As described in the Summary of the Invention section of the present disclosure, the transformer 10 is defined as having a height equal to the height H of at least one phase winding 12, the height of the phase winding 12 also including the thickness of the pressure plates 14', 14" arranged at the ends of the phase winding 12. Therefore, the first end of the transformer 10 is defined herein as including at least one first pressure plate 14' of the at least one phase winding 12, and the second end of the transformer 10 is defined as including at least one second pressure plate 14' of the at least one phase winding 12.

[0057] like Figure 2 As shown, the at least one transverse portion 32 of the partition 30 may include two transverse portions. One transverse portion 32 is disposed at the first end of the transformer 10, and one transverse portion 32 is disposed at the second end of the transformer. This configuration may be preferred because it is contemplated that the acoustic pressure in the incompressible medium is higher at the ends of the at least one phase winding 12, i.e., near the first pressure plate 14' and the second pressure plate 14". Therefore, arranging the transverse portions 32 around the first and second ends of the transformer 10 may be an effective way to block the inertial force of the incompressible medium, while leaving a major portion of the at least one phase winding 12 free of partitions, thereby improving the cooling efficiency of the incompressible medium surrounding the at least one phase winding 12.

[0058] Figure 3 and Figure 4 Another configuration is shown, in which the separator 30 has a profile that closely matches the at least one phase winding 12. In the depicted example, the separator 30 includes two transverse sections 32, each of which includes three connected tubular sections 32a, 32b, 32c that conform to the cylindrical shape of the three phase windings 12. In this way, the separator 30 is equidistant but closely spaced from the at least one phase winding 12 around the circumference of the coil turns, thereby effectively blocking the inertial forces of the incompressible medium.

[0059] Figure 5 Another configuration of the separator 30 is shown, wherein the separator 30 has at least one first portion 32′ and at least one second portion 32″, each extending transversely to the first axis z, and wherein the at least one first portion 32′ is arranged between the first end of the transformer 10 and the first wall 22′ of the transformer tank 20, and the at least one second portion 32″ is arranged between the second end of the transformer 10 and the second wall 22″ of the transformer tank 20. Thus, the separator 30 is configured to cover a larger portion of the transmission path of the inertial force caused by vibration of the end of at least one phase winding 12. If at least one transverse portion 32 is used in combination with the first portion 32′ and the second portion 32″, the first portion 32′ and the second portion 32″ can be mechanically connected, for example, welded to the transverse portion 32.

[0060] Rigid separators, separators comprising a volume compressible liner 34, and separators comprising granular material may all be used according to Figure 1-5 However, only the partitions comprising granular material can advantageously be arranged directly on the transformer tank wall 22 .

[0061] Figure 8 Figure 2 shows simulation results of the acoustic power of a transformer tank as a function of frequency. Curve B illustrates a transformer arrangement 100 according to the present disclosure, which includes a partition 30 including a volume-compressible liner 34. Curve A illustrates a conventional transformer arrangement without a partition. It can be seen that the partition 30 significantly contributes to reducing load noise.

Claims

1. A transformer device (100), comprising: - a transformer (10) comprising at least one phase winding (12) having coil turns around a coil axis (c); a transformer tank (20) having walls (22) forming a housing in which the transformer (10) is arranged, the housing containing an incompressible medium in which the transformer is immersed; a partition (30) arranged in the transformer tank (20), the partition being located between the wall (22) of the transformer tank and the at least one phase winding (12) of the transformer (10), the partition (30) having an inner surface facing the transformer and an outer surface facing the wall, and Characterized in that the partition (30) is arranged spaced apart from the at least one phase winding (12) of the transformer (10), the transformer having a first extension along a first axis (z) parallel to the coil axis (c), a second extension along a second axis (x) and a third extension along a third axis (y), the first axis, the second axis and the third axis being perpendicular to each other, and wherein the transformer (10) has a lateral side parallel to the coil axis (c), and the partition (30) has at least one lateral portion (32) aligned with the lateral side of the transformer (10), and wherein the at least one lateral portion (32) of the partition (30) surrounds the transformer (30).

2. The transformer device (100) according to claim 1, wherein: The baffle (30) is configured to have no structural resonance at twice the network frequency.

3. The transformer device (100) according to claim 1 or 2, wherein: The inner surface of the diaphragm (30) includes a volume compressible lining (34).

4. The transformer device (100) according to claim 3, wherein: The bulk modulus of the lining (34) is ≤1.7 GPa.

5. The transformer device (100) according to claim 1, wherein: The separator (30) comprises a granular material.

6. The transformer device (100) according to claim 5, wherein: The density of the granular material is greater than 870 kg / m 3 , or more preferably, greater than 1600 kg / m 3 .

7. The transformer device (100) according to claim 5 or 6, wherein: The partition (30) is arranged on the wall (22) of the transformer tank (20).

8. The transformer device (100) according to any one of claims 1 to 6, wherein: The partition (30) is spaced apart from the wall (22) of the transformer tank (20).

9. The transformer device (100) according to claim 8, wherein: At any point of the partition (30), the distance between the point of the partition (30) and the nearest portion of the at least one phase winding (12) of the transformer is smaller than the distance between the point of the partition (30) and the nearest portion of the wall (22) of the transformer tank (20).

10. The transformer device (100) according to claim 1, wherein: The transformer has a first end along the first axis (z) and an opposite second end along the first axis (z), and wherein the transformer tank (20) has a first wall (22') adjacent to the first end of the transformer (10) and extending transverse to the first axis (z) and an opposite second wall (22") adjacent to the second end of the transformer (10) and extending transverse to the first axis (z), and wherein the partition (30) has at least one first portion (32') and at least one second portion (32") both extending transverse to the first axis (z), and wherein the at least one first portion (32') is arranged between the first end of the transformer (10) and the first wall (22') of the transformer tank (22), and the at least one second portion (32") is arranged between the second end of the transformer (10) and the second wall (22") of the transformer tank (20).

Images