Capacitor

Abstract

The utility model provides a capacitor, comprising a capacitor main body, the capacitor main body comprises a housing having a top plate and a bottom plate, a capacitor core body accommodated in the housing, and a binding post extending through the top plate and electrically connected with the capacitor core body; the barrier unit is arranged below the bottom plate, and the barrier unit is tightly attached to the capacitor main body to form a continuous and gapless interface; wherein the top wall, the side wall and the bottom wall of the blocking unit are closed in the circumferential direction to form a fully-closed hollow structure, a plurality of protruding ribs are arranged on the inner surface of the bottom wall, the ribs and the side wall are arranged at specified intervals, and the ribs intersect with one another to cut the inner surface of the bottom wall into a plurality of sub-areas.

Description

Technical Field

[0001] The utility model relates to the technical field of capacitors, in particular to a capacitor with vibration reduction and noise reduction functions. Background Art

[0002] In recent decades, driven by advances in power transmission technology, economic development, and rising energy demand, UHVDC construction has entered a period of rapid growth. my country has continuously invested in and developed high-voltage and UHVDC transmission projects, with a significant increase in the number of approved projects. As the core energy conversion system of UHVDC transmission, capacitors in converter stations perform key functions such as filtering, energy storage, and reactive power compensation.

[0003] However, due to the combined effects of high harmonic currents and low-frequency noise in converter station equipment, as well as the continued increase in capacitor capacity driven by growing electricity demand, the noise and vibration generated during capacitor operation have become increasingly prominent and have gradually become a significant factor affecting the stable operation of power systems and environmental quality. For example, in power distribution systems in factories, residential communities, municipal commercial buildings, transportation tunnels, and other scenarios such as box-type substations, complete cabinets, and outdoor distribution boxes, the noise and vibration generated by capacitors can damage the surrounding environment, reduce residents' living comfort, and even interfere with the normal operation of vibration- and noise-sensitive electronic equipment.

[0004] More importantly, persistent noise not only affects the surrounding environment, but long-term, intense vibration can also significantly damage the capacitor's main structure, significantly shortening the equipment's service life and potentially causing operational failures and economic losses. Therefore, addressing capacitor noise issues through structural intervention is imperative. Utility Model Content

[0005] The purpose of the utility model is to solve the noise and vibration problems generated during the operation of a capacitor, and to provide a capacitor comprising:

[0006] a capacitor body comprising a housing having a top plate and a bottom plate, a capacitor core accommodated in the housing, and a terminal electrically connected to the capacitor core and extending through the top plate; and

[0007] a barrier unit, the barrier unit being disposed below the bottom plate and closely fitted with the capacitor body to form a continuous and gapless interface;

[0008] The top wall, the side wall and the bottom wall of the barrier unit are circumferentially closed to form a fully-closed hollow structure, an inner surface of the bottom wall is provided with a plurality of protruding ribs, the plurality of ribs are arranged at a specified distance from the side wall, the plurality of ribs intersect each other to cut the inner surface of the bottom wall into a plurality of sub-areas, and the shapes of the plurality of sub-areas are determined according to a frequency range of noise generated by the capacitor during operation or a harmonic number of a working current of the capacitor.

[0009] According to the capacitor of the utility model, preferably, the lower surface of the bottom plate of the shell constitutes the top wall of the barrier unit.

[0010] According to the capacitor of the utility model, preferably, the inside of the barrier unit is vacuum.

[0011] According to the capacitor of the utility model, preferably, the specified distance is not less than 0.5 cm, and the height of the rib is not greater than 2 / 3 of the height of the side wall of the barrier unit.

[0012] According to the capacitor of the utility model, preferably, the shapes of the plurality of sub-areas are at least one of triangle, rectangle, pentagon or hexagon.

[0013] According to the capacitor of the utility model, preferably, the plurality of ribs are arranged at a distance from the top wall.

[0014] According to the capacitor of the utility model, preferably, the surface of the plurality of ribs is coated with a damping coating.

[0015] According to the capacitor of the utility model, preferably, the barrier unit is stainless steel.

[0016] According to the capacitor of the utility model, preferably, the inside of the barrier unit is filled with sound-absorbing material.

[0017] According to the capacitor of the utility model, preferably, the top wall, the side wall and the bottom wall of the barrier unit all have rough surfaces.

[0018] According to the capacitor of the utility model, preferably, a shock-absorbing pad is arranged between the barrier unit and the bottom plate.

[0019] The utility model provides a kind of capacitor, it includes capacitor main body and the barrier unit being arranged below capacitor main body.Barrier unit is closed hollow structure by top wall, side wall and bottom wall, in conjunction with the synergies of a plurality of protruding ribs and the plurality of sub-areas formed on bottom wall, construct multidimensional wave control structure, to realize the synergies of sound-absorbing mechanism and sound insulation mechanism, systematically reduce the operating noise and vibration of capacitor. BRIEF DESCRIPTION OF DRAWINGS

[0020] The utility model embodiment is further described below with reference to the drawings, in which:

[0021] Figure 1 The front view schematic diagram of the capacitor according to the utility model embodiment is shown;

[0022] Figure 2 The side view schematic diagram of the capacitor according to the utility model embodiment is shown;

[0023] Figure 3 The internal structure schematic diagram of the barrier unit of the capacitor according to the utility model embodiment is shown. DETAILED DESCRIPTION

[0024] For the purpose of the present application, the technical solutions and advantages are more clear and explicit, the present application is further described in detail below with reference to the drawings by specific embodiments. It should be understood that the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor belong to the scope of protection of the present application.

[0025] In addition, the described features, structures or characteristics can be combined in any suitable way in one or more embodiments. In the following description, many specific details are provided to give a sufficient understanding of the embodiments of the present application. However, the person skilled in the art will realize that the technical solutions of the present application can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. can be used. In other cases, well-known methods, devices, implementations or operations are not shown or described in detail to avoid obscuring the aspects of the present application.

[0026] In the power system, the capacitor is widely used in power factor correction, filtering, energy storage and many other fields as a key device. During operation, when the capacitor applies voltage, the periodic electric force is generated between the positive and negative plates due to the alternating electric field, which drives the plate to vibrate at high frequency. The vibration is transmitted to the inner wall of the capacitor shell through the internal components and induces shell vibration, and finally radiates noise to the outside through the shell; the noise frequency is usually in multiple relationship with the voltage frequency, and the essence is the frequency multiplication effect of plate vibration after mechanical transmission. Combined with the vibration sound generation principle of the capacitor, although the vibration can be suppressed from the source by vibration reduction method, the internal electrochemical system of the capacitor unit has high stability requirement, and too many changes are not suitable for the internal structure of the capacitor body.

[0027] It is found through experiments that the noise of the capacitor has a significant directivity at the bottom of the shell, the bottom of the shell being a mounting fixed end, usually rigidly connected to the foundation by bolts, when the vibration energy is transmitted to the bottom, the rigid constraint causes the displacement to be limited, and the vibration velocity and acceleration reach the peak value at this point (similar to the vibration response of the fixed end of a cantilever beam), and the vibration transmission path composed of the insulating oil, the element and the shell is better matched in terms of wave impedance at the bottom, and the vibration energy is more easily converged and amplified; at the same time, the contact characteristics of the bottom structure and the mounting foundation make it become the main channel for the outward propagation of vibration energy. In view of the above propagation characteristics of the noise and vibration generated by the capacitor during operation, the utility model provides a capacitor with vibration and noise reduction function.

[0028] Figure 1 A front view schematic diagram of the capacitor according to an embodiment of the utility model is shown. Figure 2 A side view schematic diagram of the capacitor according to an embodiment of the utility model is shown. Figure 1 And 2 As shown in the drawings, the capacitor 10 comprises a capacitor main body 101 and a barrier unit 102. Wherein, the capacitor main body 101 comprises a shell 1011 with a top plate P1 and a bottom plate P2, a capacitor core (not shown) contained in the shell 1011 and a terminal post 1012 electrically connected with the capacitor core and extending through the top plate P1. The barrier unit 102 is arranged below the bottom plate P2, and the barrier unit 102 is closely attached to the capacitor main body 101 to form a continuous and gapless interface, so as to better absorb the noise outwardly propagated from the bottom of the capacitor main body 101. The top wall B1, the side wall B2 and the bottom wall B3 of the barrier unit 102 are circumferentially closed to form a fully enclosed hollow structure.

[0029] When the capacitor 10 is in a working state, the noise and vibration generated by the capacitor main body 101 are outwardly propagated through the shell 1011, and the bottom plate P2 is one of the main propagation channels. The barrier unit 102 is arranged below the bottom plate P2, and the top thereof is closely attached to the bottom plate P2 to form a continuous and gapless interface, so that the barrier unit 102 can effectively absorb the noise and vibration.

[0030] Figure 3 An internal structure schematic diagram of the barrier unit of the capacitor according to an embodiment of the utility model is shown. As shown in the drawings, Figure 3 As shown in the drawings, inside the barrier unit 102, a plurality of raised ribs 1021 are arranged on the inner surface of the bottom wall B3, the plurality of ribs 1021 are arranged at a specified distance D from the side wall B2, and the plurality of raised ribs 1021 intersect each other to cut the inner surface of the bottom wall B3 into a plurality of sub-regions 1022. Through this structural design, the effective absorption and barrier of the noise and vibration entering the barrier unit 102 can be realized.

[0031] The propagation carrier of noise and vibration is mechanical wave, in which the sound wave propagating in air propagates in the form of longitudinal wave, and the solid vibration propagates in the form of transverse wave and longitudinal wave. The top wall B1, the side wall B2 and the bottom wall B3 of the blocking unit 102, the plurality of protruding ribs 1021 and the plurality of sub-regions 1022 formed on the bottom wall B3 can cooperatively construct a multi-dimensional wave control structure. When the mechanical wave is incident to the surface of the plurality of protruding ribs 1021, about 30%-60% (the reflectivity depends on the matching degree of the acoustic impedance of the rib material and the incident wave medium) of the energy is directly reflected, and the remaining energy enters the adjacent sub-region through diffraction, so that the originally concentrated wave energy is dispersed into the plurality of sub-regions 1022. In other words, the originally continuous mechanical wave energy is divided from the state of "full space propagation" to the state of "multi-region limited propagation", effectively blocking the propagation of energy to the outside of the blocking unit 102.

[0032] Then, the mechanical wave entering each sub-region 1022 will form reciprocating reflection between the top wall B1, the side wall B2 and the bottom wall B3 and the plurality of protruding ribs 1021. During each reflection process, the sound wave will push the air molecules to rub against the wall or the rib, generate thermal viscous loss, and convert the mechanical wave energy into heat energy dissipation. Especially at the positions such as the corners of the sub-regions where the air flow is limited, the loss will be significantly increased. Through this process, the weakening of noise and vibration can be effectively promoted.

[0033] In some embodiments of the present application, preferably, the plurality of protruding ribs 1021 adopt high-damping alloys (such as manganese-copper alloy, iron-chromium-molybdenum alloy) or viscoelastic composite materials (such as butyl rubber-based composite materials), and when the mechanical wave propagates, more energy will be converted into heat energy dissipation due to the friction and deformation of the molecular chains in the material.

[0034] In some embodiments of the present application, the surface of the plurality of ribs 1021 can be coated with a damping coating. The damping coating can directly enhance the energy dissipation efficiency of the mechanical wave.

[0035] In some embodiments of the present application, the blocking unit 102 is filled with sound-absorbing material. The sound-absorbing material (for example, porous foam, glass wool, polyester fiber, etc.) has a large number of micropores and gaps inside, which interweave to form a complex three-dimensional network structure, which can effectively enhance the vibration and noise reduction effect.

[0036] Meanwhile, the plurality of ribs 1021 are arranged at a specified distance D from the side wall B2, and D is greater than zero. If the plurality of ribs 1021 are in contact with the side wall B2 (D = 0), a rigid connection is formed between the ribs 1021 and the side wall B2. Mechanical waves incident on the plurality of ribs 1021 will directly propagate outward along the side wall B2, which not only does not help to suppress the propagation of noise and vibration, but also can cause resonance or cause the propagation of vibration to be significantly amplified. By arranging the specified distance D, the present application breaks the rigid connection between the ribs 1021 and the side wall B2, which makes the mechanical waves need to propagate to the side wall B2 through the air (the acoustic impedance is significantly increased), which can effectively weaken the propagation of mechanical waves. In addition, the specified distance D can also cause the reflected waves between the plurality of ribs 1021 and the side wall B2 to interfere with the reflected waves in the plurality of sub-regions 1022, achieving local energy cancellation and effectively suppressing the propagation of noise and vibration.

[0037] The inventors have found that the plurality of sub-regions 1022 play an important role in the above vibration and noise reduction process, and the shape of the plurality of sub-regions 1022 can directly affect the propagation path or reflection path of the mechanical wave, thereby affecting the vibration and noise reduction effect.

[0038] Specifically, sub-regions of different shapes can achieve differentiated noise reduction effects by changing the reflection path and energy distribution characteristics of the mechanical wave inside them. The acute angle structure of the triangular sub-region can make the mechanical wave form a more intensive cross-path when reflected, enhancing the damping loss of the energy superposition area, and is particularly suitable for suppressing high-frequency noise (e.g., above 2000 Hz). The rectangular sub-region has a regular reflection path inside, which can match the standing wave mode of a specific low-frequency noise (e.g., 200-500 Hz) by adjusting the aspect ratio, and can enhance energy attenuation through resonance dissipation. The pentagonal and hexagonal sub-regions have a moderate number of edges and corners, which can disperse energy through multi-directional reflection to avoid single frequency concentration, forming a balanced wave field distribution in the medium and high frequency band (e.g., 500-2000 Hz). Therefore, the plurality of sub-regions 1022 can adopt one shape (including but not limited to triangle, rectangle, pentagon, or hexagon) or a combination of multiple shapes to achieve better vibration and noise reduction effect.

[0039] Preferably, the shape of the plurality of sub-regions 1022 can be determined according to the frequency range of the noise generated by the capacitor during operation or the harmonic number of the operating current of the capacitor. For example, when the harmonic of the operating current is mainly 3 times and 5 times (usually corresponding to low-frequency noise of 150 Hz and 250 Hz), a rectangular sub-region can be selected and a specific aspect ratio (e.g., 1:1.5) can be matched to excite the standing wave resonance mode in the sub-region, thereby improving the vibration energy attenuation rate in this frequency band and thus optimizing the control effect on specific frequency noise.

[0040] In some embodiments of the present application, the shape of the plurality of sub-regions 1022 can be at least one of a triangle, a rectangle, a pentagon, or a hexagon.

[0041] In some embodiments of the present application, the inside of the barrier unit 102 can be set as a vacuum. The vacuum environment can effectively block the propagation of noise and vibration.

[0042] In some embodiments of the present application, the specified distance D can be selected according to the frequency range of the noise generated when the capacitor is running. Preferably, the specified distance D is not less than 0.5 centimeters, at which the specified distance, the transmission of noise and vibration can be significantly weakened.

[0043] Similarly, in some embodiments of the present application, the plurality of ribs 1021 are arranged at intervals with the top wall B1. Preferably, the height of the rib 1021 is not greater than 2 / 3 of the height of the side wall B2 of the barrier unit 102.

[0044] In addition, the plurality of protruding ribs 1021 not only can enhance the stiffness of the barrier unit 102, but also can change the natural frequency distribution of the barrier unit 102. For example, the structural resonance peak can be shifted to outside the target noise frequency range to avoid the energy amplification effect caused by the resonance phenomenon, thereby further reducing the transmission efficiency of mechanical wave energy and effectively blocking the propagation of energy to the outside of the barrier unit 102.

[0045] In some embodiments of the present application, preferably, the top wall B1, the side wall B2 and the bottom wall B3 of the barrier unit 102 all have rough surfaces. The rough surface can increase the randomness of mechanical wave reflection, cause the incident wave to form multi-directional scattering at different protrusions and recesses, and suppress the propagation of noise and vibration. For solid vibration waves, the microscopic unevenness of the rough surface causes more local deformation and molecular friction during vibration transmission, further consuming mechanical wave energy and improving the overall vibration and noise reduction effect.

[0046] In some embodiments of the present application, a shock-absorbing pad (not shown) is arranged between the barrier unit 102 and the bottom plate P2.

[0047] In some embodiments of the present application, the lower surface of the bottom plate P2 of the shell 1011 constitutes the top wall B1 of the barrier unit 102. In other words, the barrier unit 102 does not have a separate top plate, but shares the bottom plate P2 with the shell 1011. This not only can reduce the volume and weight of the capacitor 10, but also can make the barrier unit 102 more efficiently absorb the noise and vibration of the capacitor body 101.

[0048] In some embodiments of the present application, the barrier unit 102 can be made of stainless steel.

[0049] In some embodiments of the utility model, the barrier unit 102 can also be arranged at other positions of the capacitor main body 101 according to requirements.

[0050] The capacitor according to the embodiments of the utility model comprises a capacitor main body and a barrier unit arranged below the capacitor main body. The barrier unit comprises a closed hollow structure formed by a top wall, a side wall and a bottom wall, and a multi-dimensional wave control structure is constructed by the synergistic effect of the plurality of convex ribs and the plurality of sub-regions formed on the bottom wall, so that the synergistic effect of the sound absorption mechanism and the sound insulation mechanism is realized, and the operation noise and vibration of the capacitor are systematically reduced.

[0051] In this specification, reference to "various embodiments", "some embodiments", "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase "in various embodiments", "in some embodiments", "in one embodiment", or "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It has to be emphasized that, according to the application, the specific features, structures, or characteristics of any one of the embodiments can be combined, in whole or in part, with the specific features, structures, or characteristics of any other embodiment, without limitation.

[0052] In this specification, the terms "comprise", "have" and similar terms are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device that includes a list of steps or units is not limited to the listed steps or units, but optionally further includes other steps or units not listed or optionally further includes other steps or units inherent to such processes, methods, products or devices. In addition, each element in the drawings of the present application is only for illustrative purposes, not drawn to scale.

[0053] Although the utility model has been described by preferred embodiments, the utility model is not limited to the embodiments described herein, and various changes and variations are included without departing from the scope of the utility model.

Claims

1. A capacitor, characterized in that: The capacitor comprises: a capacitor body comprising a housing having a top plate and a bottom plate, a capacitor core accommodated in the housing, and a terminal extending through the top plate and electrically connected to the capacitor core; and a barrier unit, the barrier unit being disposed below the bottom plate and closely fitted with the capacitor body to form a continuous and gapless interface; In which, the top wall, side wall and bottom wall of the barrier unit are circumferentially closed to form a fully enclosed hollow structure, and a plurality of raised ribs are provided on the inner surface of the bottom wall. The plurality of ribs are arranged at a specified distance from the side wall, and the plurality of ribs cross each other to cut the inner surface of the bottom wall into a plurality of sub-areas, and the shapes of the plurality of sub-areas are determined according to the frequency range of the noise generated when the capacitor is in operation or the harmonic order of the working current of the capacitor.

2. The capacitor according to claim 1, wherein The lower surface of the bottom plate of the housing forms the top wall of the blocking unit.

3. The capacitor according to claim 1, wherein The specified distance is not less than 0.5 cm.

4. The capacitor according to claim 1, wherein The shapes of the plurality of sub-regions are at least one of a triangle, a rectangle, a pentagon or a hexagon.

5. The capacitor according to claim 1, wherein The height of the rib is no greater than 2 / 3 of the height of the side wall of the barrier unit.

6. The capacitor according to claim 1, wherein Surfaces of the plurality of ribs are coated with a damping coating.

7. The capacitor according to claim 1, wherein The barrier unit is made of stainless steel.

8. The capacitor according to claim 1, wherein The interior of the barrier unit is filled with sound-absorbing material.

9. The capacitor according to claim 1, wherein The top wall, side wall and bottom wall of the barrier unit all have rough surfaces.

10. The capacitor according to claim 1, wherein A shock-absorbing pad is provided between the blocking unit and the bottom plate.

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