JPS6041715Y2 - Oil-filled power capacitor with safety device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oil-filled power capacitor with a safety device that prevents explosions due to dielectric breakdown.

Generally, when an oil-immersed power capacitor has an internal failure, a foil electrode type causes a short circuit, and a vapor-deposited electrode type causes abnormal healing, which thermally decomposes the dielectric and generates gas, increasing the internal pressure and causing the case. There is a risk of destruction, burnout of attached loads, and even a fire accident.

Therefore, it is necessary to prevent such accidents, and various types of capacitors with safety devices have been proposed, but most of them are made by mechanically disconnecting the safety device installed inside the capacitor by taking advantage of the increase in internal pressure. It is something.

However, these structures have complicated mechanisms and require a large number of parts, and especially when used in a large power capacitor, the device itself becomes large, which is disadvantageous in practice.

The present invention was developed in view of the above points, and uses the oil level inside the oil used as an impregnating agent to operate an oil level detector installed inside the capacitor. It is an object of the present invention to provide an oil-filled power capacitor with a safety device that can prevent an explosion due to dielectric breakdown of a capacitor element by being connected to a circuit breaker provided therein.

An embodiment of the present invention will be described below with reference to the drawings.

That is, as shown in FIG. 1, a capacitor element 1 constructed by, for example, known means is housed in a case body 2, and lead wires 3a, 3 led out from the capacitor element 1.
External terminals 5a and 5b are integrally fixed to the case top cover 4.
and further insert into the case body 2 an insulating fixture 7 that is fixed to the inside of the case top lid 4 and has a lower contact 6 near its tip, and the fixture 7 is inserted between the case top lid 4 and the bottom contact 6. An oil level detector 10 is disposed from a float 9 which is made movable and has an upper contact 8 at a position opposite to the lower contact 6, and the case upper cover 4 is fitted into the opening of the case body 2 and soldered. The case body 2 is filled with insulating oil 12 through the impregnating hole 11 provided in the case top lid 4, and the float 9 is filled with insulating oil 12.
2, the impregnation hole 11 was sealed by soldering 13, and the detection circuit 14 connected to the lower contact 6 and upper contact 8 of the detector 10 and the external terminals 5a and 5b were connected. The circuit breaker 15 is connected to the circuit breaker 15, and the detection circuit 14 is closed by the drop of the insulating oil 12, thereby operating the circuit breaker 15.

In the oil-filled power capacitor with a safety device configured as described above, if the insulation breaks down due to characteristic deterioration, an excessive rise in ambient temperature, or even the application of overvoltage, and the inside is filled with gas, the damage will occur as shown in Figure 2. The case body 2 expands as the internal pressure increases, and the case top cover 4 also expands.

Therefore, as a result of the internal volume increasing, the surface of the insulating oil 12 descends, and the float 9 constituting the oil level detector 10 also descends at the same time, causing the upper contact 8 constituting the float 9 to touch the lower contact 6. As a result, the detection circuit 14 connected to the upper contact 8 and the lower contact 6 is closed, and the circuit breaker 15 connected to the detection circuit 14 is operated to interrupt the capacitor circuit, thereby preventing an explosion of the capacitor. Therefore, burnout of attached loads and fire accidents can be prevented.

As described above, according to the present invention, the oil level detector is made to function by using the oil level of the insulating oil used as an impregnating agent, thereby closing the detection circuit connected to the detector, and thereby closing the detection circuit connected to the detector. It is possible to obtain an oil-filled power capacitor with a safety device, which is particularly suitable for large structures, and which can reliably prevent explosions caused by capacitor element failure by operating a connected circuit breaker.

[Brief explanation of the drawing]

1 and 2 relate to one embodiment of the present invention, in which FIG. 1 is a sectional view showing an oil-filled power capacitor with a safety device, and FIG.
This figure is a sectional view showing a state in which the oil-filled power capacitor with a safety device shown in FIG. 1 has increased internal pressure. 1...Capacitor element, 2...Case body, 4...Case top cover, 5a, 5b...
...External terminal, 6...Lower contact, 7...
・Insulating fixed object, 8...Top contact, 9...
・Float, 10...Oil level detector, 12...
・Insulating oil, 14...Detection circuit, 15...
- Breaker.

Claims (1)

[Scope of utility model registration request] A case body that houses a capacitor element, a case top lid that seals the case body and attaches an external terminal, an insulating oil filled in the case body, and a case top lid that is disposed at an upper part of the case body. An oil surface consisting of an insulating fixture that is fixed to the body and has a lower contact near its tip, and a float that allows the fixture to be inserted and moved between the case top cover and the lower contact and has an upper contact at a position opposite to the lower contact. It comprises a detector, a detection circuit connected to a lower contact and an upper contact of the detector, and a circuit breaker connected to the external terminal, and the detection circuit is closed by the descent of the insulating oil, and the circuit breaker is shut off. An oil-filled power capacitor with a safety device that allows the device to operate.