A safe explosion-proof capacitor

Abstract

The present invention discloses a safety explosion-proof capacitor, comprising: a capacitor housing, an electrode arranged on the top surface of the capacitor housing, a capacitor core group arranged inside the capacitor housing, and a cut-off box; the capacitor housing is filled with a flame-retardant resin; the cut-off box is filled with an insulating impregnant; the cut-off box is located between the internal wiring terminal of the electrode and the capacitor core group; the internal wiring terminal of the electrode is connected to the capacitor core group through a wire and through the cut-off box, and the wire located inside the cut-off box has a cut-off. When a fault occurs in the capacitor of the present invention, the wire breaks at the cut-off box, so that the capacitor is in an open circuit state, and the insulating impregnant inside the cut-off box can prevent the faulty capacitor from being turned on again due to ignition under high voltage.

Description

Technical Field

[0001] The invention relates to the technical field of capacitors, in particular to a safe explosion-proof capacitor. Background Art

[0002] As one of the three major components, capacitors are widely used in circuits. High-power metallized film capacitors are widely used in ultra-high voltage transmission and flexible direct current transmission. With the continuous increase in the voltage and capacity of metallized film capacitors, the energy storage of capacitors is also continuing to increase.

[0003] In order to prevent such metallized film capacitors with high energy storage density from exploding and catching fire when they fail, the prior art has made a variety of improvements, such as: changing the impregnating agent filled inside the capacitor from oil to a flame-retardant resin material to prevent the impregnating agent from burning; installing an explosion-proof valve on the capacitor so that the gas generated when the capacitor self-heals can be discharged in time to prevent the capacitor from exploding. However, for such metallized film capacitors with high energy storage density, neither changing the impregnating agent of the capacitor to a flame-retardant resin nor using an explosion-proof valve can completely remove the capacitor when it fails. The capacitor will repeatedly discharge at the internal fault site, gradually carbonizing the film and flame-retardant resin in the capacitor, thereby allowing the capacitor to be turned on again. Summary of the invention

[0004] In order to overcome the defects in the above-mentioned prior art, the present invention provides a safe explosion-proof capacitor, which puts the capacitor in an open circuit state when a capacitor fails, and can prevent the failed capacitor from being turned on again due to ignition under high voltage.

[0005] To achieve the above object, the present invention adopts the following technical solutions, including:

[0006] A safety explosion-proof capacitor, comprising: a capacitor housing, an electrode arranged on the upper top surface of the capacitor housing, and a capacitor core group arranged inside the capacitor housing;

[0007] Also included: a cut-off box disposed inside the capacitor housing;

[0008] The capacitor housing is filled with flame retardant resin; the cut-off box is located between the internal terminal of the electrode and the capacitor core group;

[0009] The internal terminal of the electrode is connected to the capacitor core group through a wire and a cut-off box, and the wire inside the cut-off box has a cutout;

[0010] The interior of the cut-off box is filled with an insulating impregnant.

[0011] The upper top surface and the lower bottom surface of the cutting box are respectively provided with corresponding protruding columnar through holes; the wires pass through the cutting box through the corresponding columnar through holes on the upper top surface and the lower bottom surface of the cutting box, and connect the internal wiring terminals of the electrodes with the capacitor core group.

[0012] The outer surface of the columnar through hole is provided with threads; the outer ring of the columnar through hole is screwed with nuts.

[0013] A sealing ring is arranged between the nut and the cutting box.

[0014] The cutting box is a closed type; the upper top surface and the lower bottom surface of the cutting box are provided with corresponding conductive sheets, the inner side of the conductive sheets is located inside the cutting box, and the outer side of the conductive sheets is located outside the cutting box; a wire is provided inside the cutting box, and the corresponding conductive sheets on the upper top surface and the lower bottom surface of the cutting box are connected through the internal wire, and the wire inside the cutting box has a cutout;

[0015] The internal connection terminal of the electrode is connected to the outer side of the conductive sheet on the top surface of the cutting box through a wire, and the capacitor core group is connected to the outer side of the conductive sheet on the bottom surface of the cutting box through a wire.

[0016] A plurality of electrodes are arranged on the upper top surface of the capacitor shell, and a corresponding plurality of capacitor core groups are arranged inside the capacitor shell. The internal terminal of each electrode is connected to the corresponding capacitor core group through a wire and through the same cutting box, and each wire located inside the cutting box has a cut.

[0017] The advantages of the present invention are:

[0018] (1) The design of the present invention can be applied to flame-retardant resin-filled metallized film capacitors with voltages higher than 1500VDC, capacities greater than 2000μF, and energy storage greater than 2200J. The present invention puts the capacitor in an open circuit state when a capacitor fails, and can prevent the failed capacitor from being turned on again due to ignition under high voltage. The flame-retardant resin filled inside the capacitor housing of the present invention, on the one hand, plays an insulating role, and on the other hand, after the flame-retardant resin is cured, the capacitor core group and the cut-off box can be fixed in position, so that when the capacitor fails and deforms, it is convenient for the wire to be torn off at the incision.

[0019] (2) When a capacitor fails, the upper top surface of the capacitor casing deforms and bulges, causing the connecting wire inside the capacitor casing to be torn off at the incision. After the wire breaks at the incision inside the cut-off box, the insulating impregnant filled inside the cut-off box flows between the broken incisions. After the wire breaks, the capacitor is in an open-circuit state. The insulating impregnant can prevent the faulty capacitor from being turned on again due to sparking under high voltage.

[0020] (3) The present invention arranges a sealing ring and a nut outside the raised columnar through hole to prevent leakage of the insulating impregnating agent.

[0021] (4) When a capacitor fails, the upper surface of the capacitor casing is deformed and bulged, and the wire is pulled under tension, which also applies tension to the upper surface of the cut-off box, causing the upper surface of the cut-off box to deform and bulge, so that the wire inside the cut-off box is torn off at the incision, and the insulating impregnant filled inside the cut-off box flows between the broken incisions. The wire inside the cut-off box is broken, causing the capacitor to be in an open-circuit state, and the insulating impregnant can prevent the faulty capacitor from being turned on again due to sparking under high voltage.

[0022] (5) Each conductor inside the cut-off box is notched to prevent phase imbalance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of a first embodiment of a safety explosion-proof capacitor.

[0024] Figure 2 This is a partial enlarged view of a cut-off box of a first embodiment of a safety explosion-proof capacitor.

[0025] Figure 3 This is a schematic diagram of a second embodiment of a safety explosion-proof capacitor.

[0026] Figure 4 This is a partial enlarged view of a cut-off box of a second embodiment of a safety explosion-proof capacitor.

[0027] Figure 5 A schematic diagram of a safe explosion-proof capacitor. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1:

[0030] Depend on Figure 1 As shown, a safety explosion-proof capacitor of the present invention comprises: a capacitor housing 1, three electrodes 2 arranged on the upper top surface of the capacitor housing 1, three capacitor core groups 3 arranged inside the capacitor housing 1, a cutting box 4, and a wire.

[0031] The capacitor housing 1 is filled with flame retardant resin; after the flame retardant resin is cured, the capacitor core group 3 and the cut-off box 4 inside the capacitor housing 1 can be fixed in position; the cut-off box 4 is located between the capacitor core group 3 and the internal terminal 21 of the electrode 2.

[0032] The internal connection terminal 21 of each electrode 2 is connected to the corresponding capacitor core group 3 through a wire and through the same disconnection box 4.

[0033] The interior of the cut-off box 4 is filled with an insulating impregnant.

[0034] Depend on Figure 2 As shown, the upper top surface and the lower bottom surface of the cutting box 4 are respectively provided with three corresponding protruding cylindrical through holes 401 with threads on the outer surface. The wires pass through the cylindrical through holes 401 on the upper top surface of the cutting box 4 into the interior of the cutting box 4, and pass through the cylindrical through holes 401 on the lower bottom surface of the cutting box 4 out of the cutting box 4.

[0035] The outer ring of each protruding cylindrical through hole 401 with threads on the outer surface is screwed with a nut 403 , and a rubber ring, namely a sealing ring 402 , is arranged between the nut 403 and the cutting box 4 .

[0036] The internal terminal 21 of the electrode 2 is connected to the capacitor core group 3 by passing through the cutting box 4 through the columnar through holes 401 on the upper top surface and the lower bottom surface of the cutting box 4. Each wire has a cutout 5, and the cutout 5 is located inside the cutting box 4; each wire is in a straight state.

[0037] When a capacitor is working normally, current flows through the capacitor through the wires.

[0038] When a capacitor fails, the capacitor housing 1 will be deformed, specifically, the upper top surface of the capacitor housing 1 will bulge, causing the wire that was originally in a straight state to be torn off at the incision 5. After the wire breaks at the incision 5 located inside the cutting box 4, the insulating impregnant filled inside the cutting box 4 flows between the broken incisions 5. After the wire breaks, the capacitor is in an open-circuit state, and the insulating impregnant can prevent the faulty capacitor from being turned on again due to sparking under high voltage.

[0039] Embodiment 2:

[0040] Depend on Figure 3 As shown, a safety explosion-proof capacitor of the present invention comprises: a capacitor housing 1, three electrodes 2 arranged on the upper top surface of the capacitor housing 1, three capacitor core groups 3 arranged inside the capacitor housing 1, a cutting box 4, and a wire.

[0041] The capacitor housing 1 is filled with flame retardant resin; after the flame retardant resin is cured, the capacitor core group 3 and the cut-off box 4 inside the capacitor housing 1 can be fixed in position; the cut-off box 4 is located between the internal terminal of the electrode 2 and the capacitor core group 3.

[0042] The internal connection terminal 21 of each electrode 2 is connected to the corresponding capacitor core group 3 through a wire and through the same disconnection box 4.

[0043] Depend on Figure 4 As shown, the cutting box 4 is a closed type, and the inside of the cutting box 4 is filled with an insulating impregnant. The upper top surface and the lower bottom surface of the cutting box 4 are provided with corresponding three groups of conductive sheets 411, the inner side of the conductive sheets 411 is located on the inner surface of the cutting box 4, and the outer side of the conductive sheets 411 is located on the outer surface of the cutting box 4. Three wires are provided inside the cutting box 4, and the corresponding conductive sheets 411 on the upper top surface and the lower bottom surface of the cutting box 4 are connected through the wires inside. Each wire inside the cutting box 4 has a cutout 5, and each wire inside the cutting box 4 is in a straight state.

[0044] The internal terminal 21 of the electrode 2 is connected to the outer side of the conductive sheet 411 on the top surface of the cutting box 4 through a wire, and the capacitor core group 3 is connected to the outer side of the conductive sheet 411 on the bottom surface of the cutting box 4 through a wire; each wire inside the capacitor housing 1 is in a straight state;

[0045] When the capacitor is working normally, the current flows in the capacitor through the wire and the conductive sheet 411 on the cut-off box.

[0046] When a capacitor fails, the capacitor housing 1 will be deformed, the upper surface of the capacitor housing 1 will bulge, and the wire in a straight state will be pulled to exert a pulling force on the upper surface of the cut-off box 4, so that the upper surface of the cut-off box 4 will bulge, thereby causing the internal wire of the cut-off box 4 to be torn off at the incision 5, and the insulating impregnant filled in the cut-off box 4 will flow between the broken incisions 5. The broken internal wire will put the capacitor in an open-circuit state, and the insulating impregnant can prevent the faulty capacitor from being turned on again due to sparking under high voltage.

[0047] In the second embodiment, the cut-off box 4 is located between the internal terminal of the electrode 2 and the capacitor core group 3. Preferably, Figure 5 As shown, the cut-off box 4 can be directly placed above the capacitor core group 3. The wire inside the cut-off box 4 has a cutout 5, and the cutout 5 can be located at any position inside the cut-off box. Preferably, the cutout 5 can be directly set at the inner side of the conductive sheet 411 on the bottom surface of the cut-off box 4, that is, the cutout 5 is set at the connection with the conductive sheet 411 on the bottom surface of the cut-off box 4, so that the wire is forced to be torn off at the cutout.

[0048] In the present invention, the wire is selected to have a low elongation at break. Since the current requirements of each capacitor are different, in actual use, wires of different diameters are selected according to the current, and the sizes of the cuts of wires of different diameters are also different.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A safety explosion-proof capacitor, comprising: A capacitor housing (1), an electrode (2) arranged on the upper top surface of the capacitor housing (1), and a capacitor core group (3) arranged inside the capacitor housing (1); The invention is characterized in that it further comprises: a cut-off box (4) arranged inside the capacitor housing (1); The capacitor housing (1) is filled with flame-retardant resin; the cut-off box (4) is located between the internal connection terminal (21) of the electrode (2) and the capacitor core group (3); The internal connection terminal (21) of the electrode (2) is connected to the capacitor core group (3) through a wire and through a cut-off box (4), and the wire located inside the cut-off box (4) has a cutout (5); The interior of the cutting box (4) is filled with an insulating impregnating agent; The cutting box (4) is of a closed type; the upper top surface and the lower bottom surface of the cutting box (4) are provided with corresponding conductive sheets (411); the inner side of the conductive sheet (411) is located inside the cutting box (4), and the outer side of the conductive sheet (411) is located outside the cutting box (4); a wire is provided inside the cutting box (4); the corresponding conductive sheets (411) on the upper top surface and the lower bottom surface of the cutting box (4) are connected via the internal wire, and the wire inside the cutting box (4) has a cutout (5); The internal connection terminal (21) of the electrode (2) is connected to the outer side of the conductive sheet (411) on the top surface of the cutting box (4) through a wire, and the capacitor core group (3) is connected to the outer side of the conductive sheet (411) on the bottom surface of the cutting box (4) through a wire; The upper top surface of the capacitor housing (1) is provided with three electrodes (2), the upper top surface and the lower bottom surface of the cut-off box (4) are both provided with three corresponding groups of conductive sheets (411), and the inside of the cut-off box (4) is provided with three corresponding wires.

2. A safety explosion-proof capacitor according to claim 1, characterized in that: A plurality of electrodes (2) are arranged on the upper top surface of the capacitor housing (1), and a corresponding plurality of capacitor core groups (3) are arranged inside the capacitor housing (1). The internal connection terminal (21) of each electrode (2) is connected to the corresponding capacitor core group (3) via a wire and through the same cut-off box (4), and each wire located inside the cut-off box (4) has a cutout (5).

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