阅读说明：本技术 一种低噪音干式变压器 (Low-noise dry-type transformer ) 是由 张军海 彭景伟 余小平 郭敬旺 莫向松 叶彪 罗军 廖冬虹 董记斌 吕棱 于 2021-06-01 设计创作，主要内容包括：本发明公开了一种低噪音干式变压器,包括：变压器本体,所述变压器本体包括多个线圈与铁芯；所述铁芯包括芯柱与铁轭,所述芯柱与铁轭固定连接,且所述铁轭包括上铁轭与下铁轭,所述上铁轭与下铁轭之间的第一距离,与芯柱的直径保持预设的比值；所述芯柱包括多个层叠设置的第一铁芯片,所述铁轭包括多个层叠设置的第二铁芯片,所述第一铁芯片和第二铁芯片的两端的宽度均由中部至端部端部方向逐渐减小；线圈同轴绕设于所述芯柱；所述线圈包括高压绕组与低压绕组,所述高压绕组套设于所述低压绕组外围；所述线圈外设有夹紧机构；外壳,套设于所述变压器本体。本发明有效降低变压器工作时产生的噪音,减少变压器的噪音污染。(The invention discloses a low-noise dry-type transformer, comprising: a transformer body including a plurality of coils and an iron core; the iron core comprises a core column and an iron yoke, the core column is fixedly connected with the iron yoke, the iron yoke comprises an upper iron yoke and a lower iron yoke, and a first distance between the upper iron yoke and the lower iron yoke keeps a preset ratio with the diameter of the core column; the core column comprises a plurality of first iron core sheets which are arranged in a stacked mode, the iron yoke comprises a plurality of second iron core sheets which are arranged in a stacked mode, and the widths of two ends of each of the first iron core sheets and the second iron core sheets are gradually reduced from the middle to the end part of each end part; the coil is coaxially wound on the core column; the coil comprises a high-voltage winding and a low-voltage winding, and the high-voltage winding is sleeved on the periphery of the low-voltage winding; a clamping mechanism is arranged outside the coil; the shell is sleeved on the transformer body. The invention effectively reduces the noise generated when the transformer works and reduces the noise pollution of the transformer.)

1. A low noise dry transformer, comprising:

a transformer body including a plurality of coils and an iron core; the iron core comprises a core column and an iron yoke, the core column is fixedly connected with the iron yoke, the iron yoke comprises an upper iron yoke and a lower iron yoke, and a first distance between the upper iron yoke and the lower iron yoke keeps a preset ratio with the diameter of the core column; the core column comprises a plurality of first iron core sheets which are arranged in a stacked mode, the iron yoke comprises a plurality of second iron core sheets which are arranged in a stacked mode, and the widths of two ends of each of the first iron core sheets and the second iron core sheets are gradually reduced from the middle to the end part of each end part;

the coil is coaxially wound on the core column; the coil comprises a high-voltage winding and a low-voltage winding, and the high-voltage winding is sleeved on the periphery of the low-voltage winding; a clamping mechanism is arranged outside the coil;

the shell is sleeved on the transformer body.

2. A low noise dry transformer according to claim 1, wherein a ratio of a distance between the upper and lower yokes to a diameter of the core leg is maintained to be 1:3 to 4.

3. A low noise dry transformer as claimed in claim 2, wherein said iron core has a clamping force of 0.1-0.15 Mpa.

4. A low noise dry transformer as claimed in claim 1, wherein said clamping means comprises a clamping member, a pressing member and a plurality of locking bolts; the clamping piece is fixed on the iron yoke, and the pressing piece comprises a spring and pressing pieces pressed against two ends of the spring; the locking bolt penetrates through the bolt hole of the clamping piece and is pressed on the pressing piece.

5. The low noise dry transformer of claim 1, wherein when the high voltage winding is silicone rubber-cast, an insulator space is reserved outside the high voltage winding to form an insulator integrally formed with the high voltage winding and located outside the high voltage winding, and the insulator is connected to the outlet terminal of the high voltage winding and the high voltage cable.

6. A low noise dry transformer as claimed in claim 1, wherein said core pieces are silicon steel sheets which are twice tempered and cooled.

7. A low noise dry transformer according to claim 1, further provided with a vibration damping base; the vibration reduction base is arranged below the transformer body and comprises a bearing platform and vibration reduction blocks, the transformer body is welded on the bearing platform, the vibration reduction blocks are arranged below the bearing platform, and the vibration reduction blocks are provided with a plurality of vibration reduction holes.

8. The low noise dry transformer of claim 1, wherein the housing further comprises a protective cover, the protective cover is disposed on the periphery of the transformer body, and the protective cover is coated with a water-based damping paint.

9. A low noise dry transformer according to claim 1, wherein the first core piece of the core leg is provided with a viscoelastic layer having a thickness of at least 30 μm.

10. A low noise dry transformer as claimed in claim 9, wherein the viscoelastic layer has a thickness of 40-60 μm, and the distance between each two viscoelastic layers is not equal.

Technical Field

The invention relates to the technical field of transformers, in particular to a low-noise dry-type transformer.

Background

The transformer is an electrical device for changing alternating voltage by utilizing the principle of electromagnetic induction, and has important significance in producing a power system for transmitting and distributing electric energy. The number of distribution transformers is large, most transformers are located in a living area with dense residents, continuous low-frequency noise can be continuously generated in the working process of the distribution transformers, and daily life of the residents around the transformers is seriously interfered.

At present, the transformer noise control is generally performed by testing an area with excessive noise, and a control scheme is appointed to a test result. Because the number of the noise sources is more than one, the superposition effect of the noise around the transformer substation with a plurality of transformers is more obvious, and inconvenience is brought to the use of the transformers.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a low-noise dry-type transformer, which effectively reduces the noise generated during the operation of the transformer and reduces the noise pollution of the transformer.

The purpose of the invention is realized by adopting the following technical scheme:

a low noise dry transformer comprising:

a transformer body including a plurality of coils and an iron core; the iron core comprises a core column and an iron yoke, the core column is fixedly connected with the iron yoke, the iron yoke comprises an upper iron yoke and a lower iron yoke, and a first distance between the upper iron yoke and the lower iron yoke keeps a preset ratio with the diameter of the core column; the core column comprises a plurality of first iron core sheets which are arranged in a stacked mode, the iron yoke comprises a plurality of second iron core sheets which are arranged in a stacked mode, and the widths of two ends of each of the first iron core sheets and the second iron core sheets are gradually reduced from the middle to the end part of each end part;

the coil is coaxially wound on the core column; the coil comprises a high-voltage winding and a low-voltage winding, and the high-voltage winding is sleeved on the periphery of the low-voltage winding; a clamping mechanism is arranged outside the coil;

the shell is sleeved on the transformer body.

Furthermore, the ratio of the distance between the upper iron yoke and the lower iron yoke to the diameter of the core column is 1: 3-4.

Furthermore, the clamping force of the iron core is 0.1-0.15 MPa.

Further, the clamping mechanism comprises a clamping piece, a pressing piece and a plurality of locking bolts; the clamping piece is fixed on the iron yoke, and the pressing piece comprises a spring and pressing pieces pressed against two ends of the spring; the locking bolt penetrates through the bolt hole of the clamping piece and is pressed on the pressing piece.

Further, when the high-voltage winding is subjected to silicon rubber pouring, an insulator space is reserved on the outer side of the high-voltage winding to form an insulator which is integrally formed with the high-voltage winding and located on the outer side of the high-voltage winding, and the insulator is simultaneously connected with an outlet terminal of the high-voltage winding and a high-voltage cable.

Further, the iron core sheet is a silicon steel sheet which is tempered and cooled twice.

Furthermore, a vibration damping base is also arranged; the vibration reduction base is arranged below the transformer body and comprises a bearing platform and vibration reduction blocks, the transformer body is welded on the bearing platform, the vibration reduction blocks are arranged below the bearing platform, and the vibration reduction blocks are provided with a plurality of vibration reduction holes.

Further, the shell is further provided with a protective cover, the protective cover is sleeved on the periphery of the shell, and the protective cover is coated with water-based damping paint.

Further, the first core piece of the core limb is provided with a viscoelastic layer, the thickness of which is at least 30 μm.

Further, the distance between every two viscoelastic layers is unequal, and the thickness of each viscoelastic layer is 40-60 mu m.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a low-noise dry-type transformer, which is characterized in that a preset ratio of a first distance between an upper iron yoke and a lower iron yoke to the diameter of a core column is kept, the geometric size of an iron core of the transformer is designed, an appropriate iron core magnetic density is selected, the resonance frequency of the iron core during working is calculated, and the resonance point of the working frequency of a power supply is avoided, so that the hysteresis expansion is reduced, the noise source is restrained, and the purpose of reducing noise is achieved. Meanwhile, a clamping mechanism is arranged outside the coil of the transformer, so that the vibration of the coil is further controlled, and the noise of the transformer during working is reduced.

Drawings

Fig. 1 is a schematic diagram of an iron core structure of a low noise dry-type transformer according to an embodiment of the present invention;

fig. 2 is a schematic view of a clamping member of a low noise dry type transformer according to an embodiment of the present invention;

fig. 3 is a front view of a low noise dry type transformer according to an embodiment of the present invention;

fig. 4 is a sectional view of a core leg of a low noise dry type transformer according to an embodiment of the present invention.

In the figure: 1. a stem; 2. an iron yoke; 3. a compression member; 4. a gasket; 5. a rubber insulating sheet; 6. a low voltage winding; 7. a high voltage winding; 8. a clamp; 9. a load-bearing platform; 10. and a vibration damping block.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

The vibration of the transformer mainly comes from the iron core vibration and the coil vibration, the iron core vibration mainly comes from the magnetic force generated by the magnetostriction and the magnetic leakage of the iron core piece to cause the vibration of the iron core, and the coil vibration is caused by the magnetic leakage generated by the load current. The dry-type transformer is generally placed in an underground chamber, and the generated vibration has certain influence on nearby residents and floors.

The invention provides a low-noise dry-type transformer, which effectively reduces the noise generated during the operation of the transformer and reduces the noise pollution of the transformer and is suitable for places with requirements on noise or installation conditions.

As shown in fig. 1 to 4, the present invention provides a low noise dry-type transformer, which includes a transformer body and a housing, wherein the housing is sleeved on the transformer body, the transformer body includes an iron core and a coil, and the coil includes a high voltage winding 7 and a low voltage winding 6. The iron core comprises a core column 1 and an iron yoke 2, and the coil is wound outside the core column 1. The utility model discloses a magnetic core post, including the first iron core piece of a plurality of range upon range of settings, the iron yoke 2 includes the second iron core piece of a plurality of range upon range of settings, just the width at the both ends of first iron core piece and second iron core piece reduces gradually by middle part to tip end direction, the second iron core piece is equipped with the recess with the hookup location of first iron core piece, the recess is sunken along the direction that first iron core piece reduces, first iron core piece with the crisscross concatenation of second iron core piece, the seam is the echelonment to form the magnetic flux return circuit. The step-shaped seam effectively reduces the no-load iron core loss of the transformer. Under the condition of a step-shaped joint, magnetic lines of force can vertically enter adjacent iron core pieces, no-load current is reduced, electromagnetic force acting on the iron core pieces is reduced, the iron core pieces are pressed tightly, and noise of the transformer is obviously reduced. And the step-shaped seam can effectively reduce the no-load iron core loss of the transformer, and reduce the weight and the manufacturing consumable materials of the iron core. The ratio of a first distance h between the upper iron yoke 2 and the lower iron yoke 2 to the diameter d of the core column 1 is 1: 3-4. By designing the geometric dimension of the transformer core, selecting proper core magnetic density, calculating the resonance frequency of the iron core during working, and avoiding the resonance point of the working frequency of the power supply, thereby reducing magnetostriction, restraining the source of generated noise and achieving the purpose of reducing noise.

The first iron core pieces are sequentially connected end to form a whole, so that the generation of eddy current effect on the iron core is further reduced, and the strength of the transformer iron core is increased. And the cross-section of yoke iron 2 is rectangle or "D" shape, when guaranteeing stem 1 and yoke iron 2 splice effect, reduces the weight and the preparation consumptive material and the noise reduction of iron core by a wide margin, still further reduces noise and no-load loss when practicing thrift manufacturing cost. The seam forms certain clearance space, is filled with the epoxy layer in this clearance space, and after the heat curing for the iron core piece forms a whole, improves transformer insulation system's dielectric strength and insulation resistance, with the improvement electric insulation performance, effectively reduces the turbine effect on first iron core piece and the second iron core piece, has further reduced the iron core loss.

As shown in fig. 4, the coil is coaxially wound around the core column 1, the coil includes a high-voltage winding 7 and a low-voltage winding 6, and the high-voltage winding 7 is sleeved on the periphery of the low-voltage winding 6. In the present application, the high voltage winding 7 is a winding with a relatively high voltage in the coil, and the low voltage winding 6 is a winding with a relatively low voltage in the coil. In order to reduce the vibrations of the coil that occur during operation, a clamping mechanism is provided outside the coil, as shown in fig. 2, which is used to press the high-voltage winding 7 against the low-voltage winding 6. The clamping mechanism comprises a clamping piece 8, a pressing piece 3 and a plurality of locking bolts; the clamping piece 8 is fixed on the upper iron yoke 2 and the lower iron yoke 2, and the upper iron yoke 2 and the lower iron yoke 2 transfer heat to the clamping piece 8 for heat dissipation in a heat conduction mode. The pressing piece 3 comprises a spring and pressing pieces which are pressed against two ends of the spring; the locking bolt penetrates through the bolt hole of the clamping piece 8 and is pressed on the pressing piece. And the pressing sheet below the pressing piece 3 is tightly attached to the upper surface of the gasket 4, and the lower surface of the gasket 4 is tightly attached to the high-voltage winding 7 and the low-voltage winding 6. More, still be provided with rubber insulation piece 5 between gasket 4 and high voltage winding 7, the low voltage winding 6, reduce the transmission of coil vibration through rubber insulation piece 5.

When the iron core sheet is excited, the iron core sheet generates magnetostriction, and the magnetostriction rate is closely related to the magnetic field intensity. The larger the size of the transformer core is, the larger the amount of change in relative magnetostriction is. And as the magnetic flux density is increased, the medium-high frequency energy is obviously improved, and the noise is gradually increased. Therefore, the transformer needs to have a reasonable magnetic flux density, which is 1.4-1.7T in this embodiment.

In addition, since the material of the core sheet affects the magnetostriction, in the present embodiment, a silicon steel sheet having a low magnetostriction is used. Arranging a silicon steel sheet in a subzero box to sequentially carry out primary tempering treatment, subzero treatment, secondary tempering treatment and cooling, wherein the primary tempering treatment is as follows: heating to 150-250 ℃ at the speed of 1-5 ℃/min, and preserving heat for 4-6 h; the cryogenic treatment method comprises the following steps: reducing the temperature to-160-196 ℃ at the speed of 1-5 ℃/min, and keeping the temperature for 12-24 h; the second tempering treatment method comprises the following steps: heating to 150-250 ℃ at the speed of 1-5 ℃/min, and keeping the temperature for 4-6 h; the cooling method comprises the following steps: and reducing the speed to a trial range at the speed of 1-5 ℃/min, thereby reducing the magnetostriction coefficient of the silicon steel sheet and fundamentally reducing the noise of the transformer.

In order to further reduce the magnetostriction of the ferrite core pieces and reduce the vibration of the ferrite core pieces, in the present embodiment, a viscoelastic layer having viscosity and elasticity is inserted into the lamination gap of the ferrite core pieces of the stem 1, thereby reducing the vibration of the surfaces of the ferrite core pieces. The thickness of the viscoelastic layer was set to at least 30 μm through a number of tests. In this embodiment, the thickness of the viscoelastic layer is 40 to 60 μm to enhance the vibration suppressing effect. The distance between every two viscoelastic layers is unequal, namely the viscoelastic layers are randomly arranged on the iron core sheets of the core column 1 to share the resonance frequency between the iron core sheets, so that the amplification of the vibration of the iron core sheets caused by resonance is avoided, and the transmission of the vibration of the transformer is reduced. Since the normal working dimension range of the transformer is 20-200 ℃, the station elastic layer adopts olefin film resin.

Through a plurality of tests, the dielectric constant value of the iron core piece can be increased along with the increase of the corresponding pressure, and under the condition of the same magnetic density, when the external pressure is increased, the iron core piece with larger internal stress has a higher increasing speed than the magnetostriction rate of the iron core piece with smaller internal stress. When the iron core is in the optimal clamping force range, the noise is lowest. When the clamping force is lower than the optimal range, the dead weight of the iron core pieces easily causes the whole bending deformation of the iron core because the clamping force is too small, the gaps of the iron core pieces are too large, the magnetostriction quantity is increased, and the noise of the transformer is also increased. When the clamping force is too large, the iron core pieces are too tight, the magnetostriction quantity is increased, and the noise is increased. Therefore, in this embodiment, the clamping force needs to be maintained at 0.1-0.15Mpa to reduce the hysteresis ratio of the core plate, thereby reducing the noise of the transformer.

More, the high-voltage winding 7 in the application adopts silicon rubber to be poured and integrally formed. In the pouring process, an insulator space is reserved on the outer side of the high-voltage winding 7 to form an insulator which is integrally formed with the high-voltage winding 7 and is located on the outer side of the high-voltage winding 7, and the insulator is simultaneously connected with an outlet terminal of the high-voltage winding 7 and a high-voltage cable. Because the insulator is the rubber material, when receiving high tension cable exogenic action, because the rubber material has certain elasticity, has the damping effect, consequently the difficult fracture of insulator reduces high voltage winding 7's vibration, and then reduces high voltage winding 7's vibration noise.

In order to always transmit the vibration generated by the transformer body, a vibration damping base is further provided as shown in fig. 3. The vibration reduction base is arranged below the transformer body and is specifically positioned at the contact position of the transformer body and the guide rail or the ground, so that the vibration transmission of the transformer body can be reduced. The vibration reduction base comprises a plurality of vibration reduction blocks 10 and a bearing platform 9, the transformer body is welded on the bearing platform 9, the vibration reduction blocks 10 are arranged below the bearing platform 9, and a plurality of vibration reduction holes are further formed in the vibration reduction blocks 10. The vibration reduction block 10 is made of rubber, so that the transmission of the vibration of the transformer can be greatly slowed down. The vibration reduction holes can better absorb the sound generated by vibration and better reduce the sound generated by the transformer while dissipating the heat generated by the rubber blocks. The vibration reduction base is simple to install, safe, reliable and low in cost, and influences of vibration of the transformer body on the surrounding environment are reduced.

More, low noise dry-type transformer shell still is provided with the safety cover, the safety cover is located the periphery of shell. The protective cover is coated with water-based damping paint which has strong adhesive force and better vibration and noise reduction performance. Because the transformer is required to have better heat dissipation performance and the temperature of the transformer is higher, the water-based damping paint needs to have a wider temperature range. In the preparation process of the water-based damping coating, a high polymer material with a specific function can be added according to actual requirements, so that the damping coating has stronger adaptability.

According to the low-noise dry-type transformer provided by the invention, the first distance between the upper iron yoke 2 and the lower iron yoke 2 and the diameter of the core column 1 are kept at a preset ratio, the geometric size of the transformer core is designed, the proper magnetic density of the core is selected, the resonance frequency of the core during operation is calculated, and the resonance point of the power supply operating frequency is avoided, so that the hysteresis expansion and contraction are reduced, the source of generated noise is restrained, and the purpose of reducing the noise is achieved. Meanwhile, a clamping mechanism is arranged outside the coil of the transformer, so that the vibration of the coil is further controlled, and the noise of the transformer during working is reduced.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.