CN114093664B - Filter capacitor - Google Patents

Abstract

The invention relates to a filter capacitor, which comprises a capacitor shell, a capacitor element, an incoming line, an outgoing line, a vibration isolation connecting part and a vibration damping and noise reducing device, wherein the capacitor element is arranged in the capacitor shell and is connected with the capacitor shell through the vibration damping and noise reducing device, the incoming line and the outgoing line are both flexible wires, and the vibration isolation connecting part is arranged outside the capacitor shell and is fixedly connected with the capacitor shell. It can block vibration transmission and noise propagation inside the filter capacitor.

Description

filter capacitor

technical field

The invention relates to the technical field of filter capacitors, in particular to a filter capacitor.

Background technique

When the unbalanced electric field force passes through the capacitor, it will cause the internal components of the capacitor to vibrate. According to relevant records in the reports of CIGRE and IEC, the audible noise of filter capacitors in high-voltage converter stations can reach up to 105dB(A), seriously exceeding the specified standards. Long-term excessive vibration will also cause great damage to the structure of the capacitor body, seriously reducing its service life and even causing failure, resulting in huge economic losses.

At present, filter capacitors are widely used to reduce noise by means of sound insulation cover or internal filling of sound insulation cotton, but the sound insulation cover is relatively heavy, which brings uncertain factors to the stability of the filter capacitor tower. The effect is relatively limited. Patent document CN214588463U discloses a power filter capacitor noise reduction device, which includes a base and a cylinder with an opening below; the cylinder is covered on the base to form a closed structure for placing the power filter capacitor, and the side wall and the top wall of the cylinder There is a connected sound insulation cavity inside, and the top wall of the cylinder is provided with two through holes for the conductive posts of the power filter capacitor to protrude; each through hole is provided with a The rubber ring is connected with the inner wall of the through hole through an elastic sealing material. This technical solution has a certain noise reduction effect, but it is difficult to meet the requirements when used alone.

Contents of the invention

The object of the present invention is to provide a filter capacitor to block vibration transmission and noise transmission inside the filter capacitor.

Technical scheme of the present invention is:

A filter capacitor, comprising a capacitor case, a capacitor element, an incoming line, an outgoing line, a vibration isolation connection and a vibration and noise reduction device, the capacitor element is arranged in the capacitor case and communicates with the vibration and noise reduction device through the capacitor case The capacitor case is connected, the incoming line and the outgoing line are flexible wires, and the vibration-isolation connection part is arranged outside the capacitor case and fixedly connected with the capacitor case.

Preferably, the soft wire is an annealed copper wire.

Preferably, the vibration and noise reduction device includes a lead end vibration and noise reduction device, and the lead end vibration and noise reduction device includes a soft sound-absorbing layer, a hard sound-absorbing layer and an elastic vibration-damping layer arranged in sequence, the The soft sound-absorbing layer is arranged close to the capacitor casing, and the elastic vibration-absorbing layer is arranged close to the capacitor element.

Preferably, the vibration and noise reduction device includes a non-lead end vibration and noise reduction device, and the non-lead end vibration and noise reduction device includes a vacuum sound insulation layer, a soft sound-absorbing layer, a hard sound-absorbing layer and an elastic A vibration-damping layer, the vacuum sound-insulating layer is arranged close to the capacitor casing, and the elastic vibration-damping layer is arranged close to the capacitor element.

Further preferably, the soft sound-absorbing layer is sound-absorbing cotton.

Further preferably, the hard sound-absorbing layer is a porous sound-absorbing board.

Further preferably, the elastic damping layer is polyurethane elastomer.

Still further preferably, the closed cell rate of the polyurethane elastomer is 93%-96%.

Still further preferably, an insulating and heat-conducting layer is further provided between the elastic damping layer and the capacitor element, the capacitor case is a heat-conducting body, and the insulating and heat-conducting layer is thermally connected to the capacitor case.

Preferably, the vibration and noise reduction device is composed of a lead end vibration and noise reduction device and a non-lead end vibration and noise reduction device, and the vibration isolation connection part is arranged between the lead end vibration and noise reduction device and the non-lead end vibration and noise reduction device. The side between the lead end vibration and noise reduction devices.

Preferably, the vibration-isolation connection part includes a first end shell, a second end shell, a damping spring and a polyurethane elastomer, the first end shell and the second end shell are movably connected in the connection direction, and one end of the damping spring It is fixedly connected with the first end shell, and the other end is fixedly connected with the second end shell, and the polyurethane elastomer fills the cavity between the first end shell, the second end shell and the damping spring Inside.

The beneficial effects of the present invention are:

1. The incoming and outgoing lines of the filter capacitor are set as flexible wires, which weakens the effect of vibration transmission through the incoming and outgoing lines; the vibration and noise reduction device reduces the vibration transmission effect and sound transmission between the capacitor element and the capacitor shell Effect: the vibration-isolation connection part can reduce the vibration transmission effect between the capacitor case and the support while realizing the fixing of the capacitor case and the support.

2. The purpose of the elastic vibration-damping layer being arranged close to the capacitor element is to first dampen the vibration and then silence the sound, which can reduce the sound wave energy generated by the capacitor element. In addition to the sound-absorbing effect, the hard sound-absorbing layer can also distribute the vibration shock transmitted by the elastic damping layer. The difference between sound-absorbing materials and sound-insulating materials is that: sound-absorbing materials reduce sound transmittance by reflecting sound waves; sound-absorbing materials reduce sound transmittance by dissipating sound wave energy. The vibration source of the filter capacitor mainly acts on the lead end and non-lead end of the capacitor case, and its side vibration is relatively small. The use of the sound insulation layer will cause the sound waves transmitted to the end to pass through from the side, which is not conducive to noise reduction.

3. The sound-absorbing effect of the sound-absorbing cotton is good, and the higher the opening ratio, the better the sound-absorbing effect. However, its elasticity is poor, so an elastic damping layer is required for vibration reduction.

4. The porous sound-absorbing panel can absorb sound, and its rigidity can distribute the vibration shock transmitted by the elastic damping layer.

5. When polyurethane is used as an elastomer, the higher the closed cell ratio, the better the elasticity.

6. The polyurethane elastomer with a closed cell rate of 93% to 96% can take into account both sound wave reflectivity and elasticity. When the closed cell ratio exceeds 96%, a large amount of sound will come out from the side of the filter capacitor, and the sound wave energy absorbed by the soft sound-absorbing layer is small. When the closed cell ratio is lower than 93%, the elastic effect of the polyurethane elastomer is poor, and the vibration damping effect is poor, resulting in excessive vibration being transmitted to the soft sound-absorbing layer, compressing the pores in the soft sound-absorbing layer, resulting in poor sound-absorbing effect.

7. Polyurethane elastomer has heat insulation effect, and an insulation and heat conduction layer is set between the elastic damping layer and the capacitor element, which can improve the heat dissipation effect of the filter capacitor.

8. The vibration isolation connection part is set on the side between the vibration and noise reduction device at the lead end and the vibration and noise reduction device at the non-lead end, which can reduce the lateral shaking range of the filter capacitor under vibration and improve the use of the filter capacitor life.

Description of drawings

FIG. 1 is a schematic structural diagram of a filter capacitor.

FIG. 2 is a structural schematic diagram of a vibration-isolation connection part of a filter capacitor.

Explanation of reference signs, 1-capacitor shell, 2-capacitor element, 31-incoming wire, 32-outlet wire, 4-lead end vibration and noise reduction device, 41-first soft sound-absorbing layer, 42-first hard sound-absorbing layer Sound-absorbing layer, 43-the first elastic vibration-absorbing layer, 5-non-lead terminal vibration-damping and noise-reducing device, 51-vacuum sound-insulating layer, 52-the first soft sound-absorbing layer, 53-the first hard sound-absorbing layer, 54-the first An elastic damping layer, 6-vibration-isolation connection part, 61-first end shell, 62-second end shell, 63-damping spring, 64-polyurethane elastomer.

Detailed ways

The present invention will be described in the form of embodiments below in conjunction with the accompanying drawings, so as to assist those skilled in the art to understand and realize the present invention. Unless otherwise stated, the following embodiments and technical terms therein should not be understood without departing from the background of technical knowledge in this technical field.

Embodiment 1: A filter capacitor, referring to Fig. 1, includes a capacitor case 1, a capacitor element 2, an incoming line 31, an outgoing line 32, a vibration isolation connection part 6 and a vibration and noise reduction device, and the capacitor element 2 is arranged on the capacitor case 1, the capacitor element 2 is connected to the capacitor case 1 through a vibration and noise reduction device, the incoming line 31 and the outgoing line 32 are soft wires, the vibration isolation connection part 6 is arranged outside the capacitor case 1, and the vibration isolation connection part 6 and The capacitor housing 1 is fixedly connected.

In this embodiment, the soft wire is an annealed copper wire.

In this embodiment, the vibration and noise reduction device is composed of the lead end vibration and noise reduction device 4 and the non-lead end vibration and noise reduction device 5, and the vibration isolation connection part 6 is arranged on the lead end vibration and noise reduction device 4 and the non-lead end. The side between the vibration and noise reduction devices 6.

In this embodiment, the lead end vibration and noise reduction device 4 includes a first soft sound-absorbing layer 41, a first hard sound-absorbing layer 42 and a first elastic vibration-absorbing layer 43 arranged in sequence, and the first soft sound-absorbing layer 41 is close to The capacitor case 1 is arranged, and the first elastic damping layer 43 is arranged close to the capacitor element 2 .

Wherein, the first soft sound-absorbing layer 41 is selected from sound-absorbing cotton. The first hard sound-absorbing layer 42 is a porous sound-absorbing board. The first elastic damping layer 43 is made of polyurethane elastomer. The closed cell rate of polyurethane elastomer is selected from 93% to 96%.

In this embodiment, the non-lead terminal vibration and noise reduction device 2 includes a vacuum sound insulation layer 51, a second soft sound absorption layer 52, a second hard sound absorption layer 53, and a second elastic vibration absorption layer 54 arranged in sequence. The layer 51 is arranged close to the capacitor housing 1 and the second elastic damping layer 54 is arranged close to the capacitor element 2 .

Wherein, the second soft sound-absorbing layer 52 is selected from sound-absorbing cotton. The second hard sound-absorbing layer 53 is a porous sound-absorbing board. The second elastic damping layer 54 is selected from polyurethane elastomer. The closed cell rate of polyurethane elastomer is selected from 93% to 96%.

In order to enhance the heat dissipation effect of the filter capacitor, a first insulating and heat-conducting layer (not shown) is also provided between the first elastic damping layer 43 and the capacitor element 2, and the capacitor housing 1 is a heat conductor, and the first insulating and heat-conducting layer is connected to the capacitor The housing 1 is thermally connected. A second insulating and heat-conducting layer (not shown) is also provided between the second elastic damping layer 54 and the capacitor element 2 , and the second insulating and heat-conducting layer is thermally connected to the capacitor case 1 . Common insulating and heat-conducting layers include heat-conducting silicone sheets and non-silicon heat-conducting pads.

In this embodiment, referring to FIG. 2 , the vibration-isolation connecting part 6 includes a first end shell 61, a second end shell 62, a damping spring 63 and a polyurethane elastomer 64. The first end shell 61 and the second end shell 62 are connected in the direction of connection. One end of the damping spring 63 is fixedly connected to the first end shell 61, and the other end is fixedly connected to the second end shell 62. Polyurethane elastomer 64 is filled between the first end shell 61, the second end shell 62 and the damping spring 63. in the cavity between. The first end shell 61 is fixedly connected to the capacitor housing 61 .

The present invention has been described in detail above in conjunction with the accompanying drawings and embodiments. It should be understood that it is impossible to exhaustively describe all possible implementation modes in practice, and the inventive concept of the present invention is illustrated here as much as possible by way of illustration. Under the premise of not departing from the inventive concept of the present invention and without paying creative work, those skilled in the art can make trade-offs and combinations of the technical features in the above-mentioned embodiments, carry out experimental changes on specific parameters, or use existing The specific embodiments formed by routinely replacing the technical means disclosed in the present invention shall all belong to the content implicitly disclosed in the present invention.

Claims (5)

1. A filter capacitor, comprising a capacitor housing, a capacitor element, an incoming line, and an outgoing line, characterized in that it also includes a vibration isolation connection and a vibration and noise reduction device, and the capacitor element is arranged in the capacitor housing and passed through The vibration and noise reduction device is connected to the capacitor case, the incoming and outgoing lines are soft wires, and the vibration isolation connection part is arranged outside the capacitor case and fixedly connected to the capacitor case; The vibration and noise reduction device includes a lead end vibration and noise reduction device, and the lead end vibration and noise reduction device includes a first soft sound-absorbing layer, a first hard sound-absorbing layer and a first elastic shock-absorbing layer arranged in sequence , the first soft sound-absorbing layer is disposed close to the capacitor housing, and the first elastic damping layer is disposed close to the capacitor element; The vibration and noise reduction device includes a non-lead end vibration and noise reduction device, and the non-lead end vibration and noise reduction device includes a vacuum sound insulation layer, a second soft sound-absorbing layer, a second hard sound-absorbing layer and a second elastic damping layer, the vacuum sound insulation layer is disposed close to the capacitor housing, and the second elastic damping layer is disposed close to the capacitor element; Both the first elastic damping layer and the second elastic damping layer are first polyurethane elastomers, and the closed cell rate of the first polyurethane elastomers is 93% to 96%; The vibration isolation connection part is arranged on the side between the vibration and noise reduction device at the lead end and the vibration and noise reduction device at the non-lead end; The vibration-isolation connection part includes a first end shell, a second end shell, a damping spring and a second polyurethane elastic body, the first end shell and the second end shell are movably connected in the connection direction, and one end of the damping spring is connected to the second end shell The first end shell is fixedly connected, and the other end is fixedly connected to the second end shell, and the second polyurethane elastomer fills the space between the first end shell, the second end shell and the damping spring cavity. 2. The filter capacitor according to claim 1, wherein the soft wire is an annealed copper wire. 3. The filter capacitor according to claim 1, wherein the first hard sound-absorbing layer and the second hard sound-absorbing layer are both porous sound-absorbing panels. 4. The filter capacitor according to claim 1, wherein an insulating and heat-conducting layer is also provided between the elastic damping layer and the capacitor element, the capacitor housing is a heat-conducting body, and the insulating and heat-conducting layer is connected to the Thermally conductive connection to the capacitor case. 5 . The filter capacitor according to claim 1 , wherein the vibration and noise reduction device is composed of a lead terminal vibration and noise reduction device and a non-lead terminal vibration and noise reduction device.

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