Low-voltage parallel capacitor

Abstract

The low-voltage parallel capacitor comprises a capacitor body, a rigid sleeve, a power-off assembly and a liquid bag, the input end of the capacitor body is fixedly connected with a power connection end, and the power-off assembly is fixedly installed at one end of the power connection end. The rigid sleeve fixedly sleeves the outer side of the capacitor body, the inner side of the rigid sleeve is provided with a cavity used for placing the liquid bag, one side of the liquid bag is attached to the surface of the capacitor body, the end portion of the liquid bag is communicated with the damper, and the other end of the damper is communicated with the interior of the power-off assembly through a guide pipe. The power-off assembly comprises a hydraulic box, an elastic film and a pole fixed to the surface of the hydraulic box. According to the utility model, the novel expansion type power-off explosion-proof assembly is arranged, the rigid sleeve on the surface of the capacitor main body is utilized to perform liquid package installation limiting, and when the capacitor main body generates an overvoltage expansion mode, the liquid package is extruded so as to cut off circuit connection of the power-off assembly, thereby realizing rapid power-off, improving safety performance, and keeping long-term stable use. The structure is simple;

Description

Technical Field

[0001] The utility model relates to the technical field of electric power equipment, in particular to a low-voltage parallel capacitor. Background Art

[0002] Shunt capacitors are commonly used in power systems to compensate for reactive power generated by inductive loads, thereby increasing power factor, improving voltage quality, and reducing line losses. They contain multiple capacitor cores, which are usually made of metallized film and made by winding or gold spraying. During use, if the capacitor is overheated or over-pressured, the metallized film may break down or self-heal, thereby generating gas, increasing the gas pressure inside the capacitor, and even causing bulging, deformation, or explosion.

[0003] To prevent this from happening, existing capacitors are usually equipped with explosion-proof devices. These explosion-proof devices can detect changes in the gas pressure inside the capacitor and play a role in power-off explosion prevention when the gas pressure increases significantly. One common explosion-proof device is to use the principle of breaking the copper wire by changing the gas pressure. When the gas pressure increases to a certain level, the explosion-proof device will be triggered, causing the copper wire to break, thereby cutting off the circuit between the capacitor and the power supply to prevent further dangerous situations. However, the copper wire may age, corrode or be mechanically damaged under long-term use or under the influence of external environmental conditions, thereby reducing its reliability. The triggering of the explosion-proof device requires the copper wire to break, which may take a certain amount of time, and during this period the gas pressure inside the capacitor may have increased significantly, causing safety hazards. Therefore, the response speed of the explosion-proof device may not be enough to cope with emergencies. Once the explosion-proof device is triggered, the copper wire will break, the circuit will be interrupted, and a new explosion-proof device needs to be replaced to resume the use of the capacitor. This makes the explosion-proof device a one-time use feature, requiring periodic inspection and replacement, which increases maintenance costs and workload. In addition, the copper wire breakage is a passive protection measure that can only be triggered when the gas pressure inside the capacitor increases significantly. For other potential safety hazards, such as damage to the internal structure of the capacitor or excessive temperature, explosion-proof devices may not provide effective protection. In view of this, the existing problems are studied and improved, and a low-voltage parallel capacitor is provided to solve the current problems. The purpose is to solve the problems and improve the practical value through this technology. Utility Model Content

[0004] The utility model aims to solve one of the technical problems existing in the prior art or related technology.

[0005] To this end, the technical solution adopted by the utility model is: a low-voltage parallel capacitor, comprising: a capacitor body, a rigid sleeve, a power-off component and a liquid bag, the input end of the capacitor body is fixedly connected with a power connection terminal, the power-off component is fixedly installed on one end of the power connection terminal, the rigid sleeve is fixedly sleeved on the outside of the capacitor body and the inner side of the rigid sleeve is provided with a cavity for placing the liquid bag and one side of the liquid bag is in contact with the surface of the capacitor body, the end of the liquid bag is connected by a damper and the other end of the damper is connected to the interior of the power-off component through a conduit, the power-off component comprises a hydraulic box, an elastic membrane and a pole fixed to the surface of the hydraulic box, the surface of the elastic membrane is provided with a moving electrode abutting and in contact with the end of the power connection terminal, and the moving electrode is electrically connected to the end of the pole.

[0006] In a preferred example, the utility model can be further configured as follows: the rigid sleeve has a metal shell structure, and the liquid bag is located between the capacitor body and the rigid sleeve.

[0007] In a preferred example, the utility model can be further configured as follows: micropores for limiting the flow of liquid are provided inside the damper to provide resistance to the flow of liquid between the power-off component and the liquid bag.

[0008] In a preferred example, the utility model can be further configured as follows: the outer periphery of the moving electrode is fixedly connected to the inner wall of the hydraulic box, and the inner cavity of the hydraulic box is divided into two cavity structures, the top cavity of the elastic membrane is provided with a pressure relief valve, and the bottom cavity of the elastic membrane is connected to the end of the damper.

[0009] In a preferred example, the utility model can be further configured as follows: the liquid bag is a flexible rubber material component, and the interior of the liquid bag is filled with insulating oil.

[0010] In a preferred example, the utility model can be further configured as follows: a spring fixedly connected to the pole is provided on the top of the movable electrode, and the movable electrode and the pole are electrically connected via the spring.

[0011] The beneficial effects achieved by the utility model are:

[0012] 1. In the utility model, a new expansion-type power-off explosion-proof component is provided, and a rigid sleeve on the surface of the capacitor body is used to limit the installation of the liquid bag. When the capacitor body is over-pressured, the liquid bag is squeezed to cut off the circuit connection of the power-off component, thereby achieving rapid power off, improving safety performance, and maintaining long-term stable use. The structure is simple and maintenance is convenient.

[0013] 2. In the utility model, through the heat conduction effect of the rigid sleeve and the liquid bag and the surface of the capacitor body, the oil inside the liquid bag is heated when the capacitor body is over-temperature working, so that after reaching the specified temperature, the thermal expansion pushes the internal contacts of the power-off component to separate and cut off the power, thereby realizing over-temperature and over-voltage protection for the capacitor body and improving the safety protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the utility model;

[0015] Figure 2 This is a schematic diagram of the installation structure of a power-off component and a liquid bag according to an embodiment of the utility model;

[0016] Figure 3 This is a schematic diagram of the cross-sectional structure of a power-off component according to an embodiment of the utility model;

[0017] Figure 4 The figure is a schematic diagram of the liquid bag structure of one embodiment of the utility model.

[0018] Reference numerals:

[0019] 100, capacitor body; 110, power connection terminal; 200, rigid sleeve; 300, power-off assembly; 310, hydraulic box; 320, elastic membrane; 311, pole; 321, moving electrode; 400, liquid bag; 410, damper. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in combination with specific implementation methods and with reference to the accompanying drawings. It should be noted that the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

[0021] A low-voltage parallel capacitor provided by some embodiments of the utility model is described below in conjunction with the accompanying drawings.

[0022] Combination Figure 1-4As shown, the utility model provides a low-voltage parallel capacitor, comprising: a capacitor body 100, a rigid sleeve 200, a power-off assembly 300 and a liquid bag 400, the input end of the capacitor body 100 is fixedly connected to a power terminal 110, the power-off assembly 300 is fixedly installed on one end of the power terminal 110, the rigid sleeve 200 is fixedly sleeved on the outside of the capacitor body 100, and the inner side of the rigid sleeve 200 is provided with a cavity for placing the liquid bag 400, and one end of the liquid bag 400 is fixedly mounted on the outside of the rigid sleeve 200. The side is fitted with the surface of the capacitor body 100, the end of the liquid bag 400 is connected to the damper 410 and the other end of the damper 410 is connected to the interior of the power-off component 300 through a conduit. The power-off component 300 includes a hydraulic box 310, an elastic membrane 320 and a pole 311 fixed to the surface of the hydraulic box 310, and the surface of the elastic membrane 320 is provided with a movable electrode 321 that abuts and fits with the end of the power terminal 110, and the movable electrode 321 is electrically connected to the end of the pole 311.

[0023] In this embodiment, the rigid sleeve 200 has a metal shell structure, and the liquid bag 400 is located between the capacitor body 100 and the rigid sleeve 200 .

[0024] Specifically, the rigid sleeve 200 is used to improve the heat dissipation effect of the capacitor body 100 and to fix and limit the liquid bag 400.

[0025] In this embodiment, micro holes for limiting the flow of liquid are provided inside the damper 410 to provide resistance to the flow of liquid between the power-off assembly 300 and the liquid bag 400 .

[0026] Specifically, a certain resistance is given to the movement of the liquid so as to prevent the liquid bag 400 from causing an internal short circuit in the power-off component 300 when the temperature is below the set safety temperature.

[0027] In this embodiment, the outer periphery of the moving electrode 321 is fixedly connected to the inner wall of the hydraulic box 310, and the inner cavity of the hydraulic box 310 is divided into two cavity structures. The top cavity of the elastic membrane 320 is provided with a pressure relief valve, and the bottom cavity of the elastic membrane 320 is connected to the end of the damper 410.

[0028] Specifically, the elastic film 320 is driven to deform and move under the action of the oil pressure, thereby driving the moving electrode 321 to fit with the end of the power connection terminal 110 for power connection or to separate from the power connection terminal 110 for circuit disconnection.

[0029] In this embodiment, the liquid bag 400 is a flexible rubber material component, and the interior of the liquid bag 400 is filled with insulating oil.

[0030] Specifically, the disconnection of the power-off component 300 is achieved by deformation of the liquid bag 400 or expansion of the internal oil due to heat, thereby performing rapid power-off protection.

[0031] In this embodiment, a spring fixedly connected to the pole 311 is provided on the top of the movable electrode 321 , and the movable electrode 321 and the pole 311 are electrically connected via the spring.

[0032] Specifically, the spring component is used to achieve rapid resetting of the moving electrode 321 and to connect the circuit.

[0033] The working principle and use process of this utility model:

[0034] During operation, the low-voltage parallel capacitor is connected to the power grid through the pole 311, and a passage state is formed by the electrical connection of the pole 311, the moving electrode 321, and the power terminal 110; when an unexpected state such as over-temperature or over-pressure occurs during operation of the capacitor body 100, the liquid bag 400 is squeezed in an expansion manner when an over-pressure occurs in the capacitor body 100, so that the liquid inside the liquid bag 400 flows into the power-off component 300 after passing through the damper 410, or the oil inside the liquid bag 400 is heated during over-temperature operation of the capacitor body 100, so that after reaching a specified temperature, the liquid flow expands and flows into the power-off component 300, so that the hydraulic pressure inside the hydraulic box 310 increases, the elastic membrane 320 is pushed up and deformed, and the moving electrode 321 is separated from the surface of the power terminal 110 to cut off the circuit for safety protection.

[0035] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A low voltage shunt capacitor, characterized in that: include: A capacitor body (100), a rigid sleeve (200), a power-off assembly (300) and a liquid bag (400), wherein the input end of the capacitor body (100) is fixedly connected to a power connection terminal (110), the power-off assembly (300) is fixedly mounted on one end of the power connection terminal (110), the rigid sleeve (200) is fixedly sleeved on the outside of the capacitor body (100), a cavity for placing the liquid bag (400) is provided on the inside of the rigid sleeve (200), and one side of the liquid bag (400) is in contact with the surface of the capacitor body (100). The end of the liquid bag (400) is connected to the damper (410), and the other end of the damper (410) is connected to the inside of the power-off assembly (300) through a conduit. The power-off assembly (300) comprises a hydraulic box (310), an elastic membrane (320), and a pole (311) fixed to the surface of the hydraulic box (310). The surface of the elastic membrane (320) is provided with a movable electrode (321) that abuts and fits with the end of the power terminal (110), and the movable electrode (321) is electrically connected to the end of the pole (311).

2. A low voltage shunt capacitor according to claim 1, characterized in that: The rigid sleeve (200) has a metal sleeve structure, and the liquid bag (400) is located between the capacitor body (100) and the rigid sleeve (200).

3. A low voltage shunt capacitor according to claim 1, characterized in that: The damper (410) is provided with micropores inside for limiting the flow of liquid, so as to provide resistance for the flow of liquid between the power-off component (300) and the liquid bag (400).

4. A low voltage shunt capacitor according to claim 1, characterized in that: The outer periphery of the movable electrode (321) is fixedly connected to the inner wall of the hydraulic box (310), and the inner cavity of the hydraulic box (310) is divided into two cavity structures. The top cavity of the elastic membrane (320) is provided with a pressure relief valve, and the bottom cavity of the elastic membrane (320) is connected to the end of the damper (410).

5. A low voltage shunt capacitor according to claim 1, characterized in that: The liquid bag (400) is a flexible rubber material component, and the interior of the liquid bag (400) is filled with insulating oil.

6. A low voltage shunt capacitor according to claim 1, characterized in that: A spring fixedly connected to the pole (311) is provided at the top of the movable electrode (321), and the movable electrode (321) and the pole (311) are electrically connected via the spring.

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