JPH021854Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a capacitor with a built-in disconnection device that is equipped with a device to disconnect the capacitor from the main circuit in the event of an internal abnormality.

Conventionally, when an internal abnormality occurs in a capacitor, the abnormality is detected internally or externally, and the signal is extracted to open a circuit breaker installed outside the capacitor circuit. In all of these methods, it is necessary to install an external shutoff device in case of an abnormality inside the capacitor, which requires installation space and is expensive.

This invention eliminates the above-mentioned drawbacks and is a capacitor that has a built-in device that automatically disconnects the capacitor from the circuit in the event of a capacitor accident.This simplifies the external protection circuit and minimizes the capacitance that must be disconnected due to an accident. This is what I am trying to do.

The present invention will be described below with reference to embodiments shown in FIGS. 1 to 4.

As shown in Fig. 1, the capacitor element assembly housed in the capacitor container 9 is bridge-connected for single-phase use, and divided into two groups for three-phase use as shown in Fig. 2. The wires are connected in a double star shape, and the heating resistor 2 is connected between each neutral point _N1 and _N2 . As shown in FIG. 3A, the heating element 2 has a thin plate shape and is wound around a relay body 3 made of a low melting point metal or a thermoplastic resin that melts or deforms when heated. Further, both ends of the relay body 3 are connected to a fixed frame 6 by a spring 4, so that stress is always applied thereto, and each end is connected to a U-shaped insulating plate 7. A fuse 5 is attached between the insulating plates 7, and one end of the fuse 5 is electrically connected to the capacitor element 1, and the other end is electrically connected to the terminal portion 8. Further, the container 9 is filled with insulating oil and sealed. Note that the fixed frame 6 may be the wall surface of the container 9.

The capacitor with a built-in interrupter of the present invention is constructed as described above.

Therefore, when current flows between the neutral points N ₁ and N ₂ of multiple capacitors 1 such as single-phase bridge connection, three-phase star connection, etc. due to dielectric breakdown of the capacitor element 1, the heating resistor 2 generates heat. As shown in FIG. 3B, the relay body 3 made of a low melting point metal or thermoplastic resin is melted or deformed, and the two insulating plates 7 connected to the relay body 3 are spread out by the stress of the spring 4. Therefore, tension is applied to the fuse 5 attached to the insulating plate 7, and the fuse 5 is quickly blown out, thereby safely and reliably cutting off the capacitor from the main circuit.

FIG. 4 shows another embodiment in which the spring 4 is connected only to one end of the relay body 3, and the same effect as described above is obtained.

The shape of the relay body 3 is not limited to a thin plate shape, but may be a thin rod shape, and the heat generating resistor 2 is not wrapped around the relay body 3, but is brought into contact with the relay body 3, so that the relay body 3 is heated. Any material that can be melted or deformed may be used, and the shape can be selected as appropriate.

Further, in the above-described embodiment, instead of the fuse 5, a conductor provided with a weak point that is cut by tension may be used.

As mentioned above, the capacitor with a built-in disconnection device of the present invention has extremely great practical value as it uses unbalanced current to forcibly apply stress to the disconnection part of the main circuit to safely and reliably disconnect it. It is.

[Brief explanation of the drawing]

Figures 1 and 2 are circuit examples of a capacitor with a built-in disconnection device of the present invention, Figure 3A is an explanatory diagram of the main parts of an embodiment of a capacitor with a built-in disconnection device of the present invention before operation, and Figure B is an illustration after the same operation. FIG. 4 is an explanatory diagram of the essential parts of another embodiment of the capacitor with a built-in interrupter according to the present invention. 1...Capacitor element, 2...Heating resistor, 3
...Relay body, 4...spring, 5...fuse.

Claims (1)

[Claims for Utility Model Registration] (1) A heating resistor connected between the neutral points of multiple capacitors, such as a single-phase bridge connection or a three-phase star connection, and a heating resistor that melts or deforms due to the heat generated by the heating resistor. A capacitor with a built-in disconnection device comprising a relay body, a spring coupled so as to apply stress to the relay body, and a fuse or conductor that is disconnected by the stress of the spring and electrically disconnected from the main circuit. (2) The capacitor with a built-in interrupting device according to claim 1, wherein the relay body is made of thermoplastic resin. (3) A capacitor with a built-in interrupting device according to claim 1, wherein the relay body is made of a low-melting point metal.