JPH1079310A - Electric equipment and protecting method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric equipment where the pressure-sealed tank of an incombustible electric apparatus provided with incombustible liquid as insulating medium can be lessened in size, it is easily detected when its pressure gas partitioned chamber has an accident, and a failure position can be easily judged. SOLUTION: An electric equipment body 4 is housed in a hermetically sealed case 1, the sealed case 1 is charged with incombustible liquid 5, and when the incombustible liquid 5 is compressed with inert insulating gas 10, the required volume of inert insulating gas 10 is composed of cases such as an on-load tap changer housing case 6, a high-voltage cable case 8 and others, these cases are linked together with a connecting piping 15, and throttle valves 16 are provided in the connecting piping 15 at prescribed positions, whereby it is easily detected when a trouble occurs at these partitioned sections.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric equipment and a method for protecting the same, and more particularly to a pressurization in which an insulating medium and an electric equipment main body are housed in a sealed container and the insulating medium is applied with a pressure higher than atmospheric pressure. TECHNICAL FIELD The present invention relates to an electric equipment having a device and a method for protecting the same.

[0002]

2. Description of the Related Art There are two types of electric equipment commonly used in the prior art: gas insulation type and liquid immersion type.
Among them, the gas insulated type is a type in which an insulating gas is sealed in a sealed container (tank) containing a load tap changer and an electric device main body.
Japanese Patent Application Laid-Open Publication No. H11-163,086 discloses a gas insulated transformer in which a tap changer under load and a transformer main body are housed in a tank filled with insulating gas.

On the other hand, in the liquid immersion type, a non-combustible liquid (for example, perfluorocarbon) for cooling and insulating is sealed in a sealed container, and the non-flammable liquid immerses the on-load tap changer and the induction electric device. Insulating and cooling these devices. Japanese Unexamined Patent Publication (Kokai) No. 3-129710, for example, relates to this liquid immersion type.

The liquid immersion type is generally used for a large-capacity type because of its superior cooling property as compared with the gas insulation type described above. And the main body of the electric equipment are immersed together in a nonflammable liquid in a sealed container, so that the space in the container is large and a large amount of expensive nonflammable liquid is required.

For this reason, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-249525, the insulating property of the non-combustible liquid is improved to reduce the amount of the non-combustible liquid. In other words, this device divides the electric device main body housing room and the load tap switching housing room using a partition plate, immerses only the electric device main body housing room in the nonflammable liquid, and supplies SF6 gas to the load tap switching housing room. And pressurized. In this case, the detection of a ground fault or the like is performed by an impact gas pressure relay attached to the load tap changer accommodating chamber so as to protect the equipment.

[0006]

With the liquid immersion type electric equipment provided as described above, the volume of the pressurizing device is limited to the volume of the nonflammable liquid as described in the above-mentioned publication. Since 30% of the volume is required, the size of the electric device is increased. For this reason, the tap change chambers and cable chambers under load are connected by connecting pipes to secure the required volume. However, when a ground fault occurs, the impact gas pressure installed in the tap chamber under load is detected. Because it is done with a relay,
There was a risk that an accident could not be detected due to the thickness of the connecting pipe or the distance from the mounting portion of the impact gas pressure relay, or damage could be increased due to a delay in detection.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and it is an object of the present invention to reduce the size of a pressurized and sealed tank of a non-combustible electric device in which a non-combustible liquid is used as an insulating medium. It is an object of the present invention to provide an electrical equipment and a method for protecting the electrical equipment that can easily detect an accident in a compartment and determine an accident point.

[0008]

That is, the present invention relates to a high-pressure container in which an insulating medium and a sealed container containing an electric equipment main body immersed in the medium are communicated with a high-voltage cable drawn from the electric equipment main body. A cable chamber, a low-voltage connection chamber through which a low-voltage cable drawn from the electric device body communicates, and a tap changer accommodating chamber in which a load tap changer is housed. In an electric equipment having a pressurizing device for applying a pressure equal to or higher than the atmospheric pressure to the medium in response to a pressure fluctuation of an insulating medium, the pressurizing device includes a high-pressure cable chamber, a low-pressure connecting chamber, and a load tap changer housing chamber. Are connected to each other through a connecting pipe so that these chambers are formed to have a pressure higher than the atmospheric pressure, and an impact gas pressure relay device for detecting an accident is provided for each of these chambers. It is obtained so as to achieve the intended purpose.

In this case, a flow rate adjusting device for adjusting the flow rate of gas flowing to another gas chamber is provided at the connection pipe. Further, the flow rate adjusting device for adjusting the gas flow rate is formed by a throttle valve.

[0010] The present invention also provides a sealed container containing an insulating medium and an electric device main body immersed in the medium.
A high-voltage cable chamber to which a high-voltage cable drawn from the electric device main body communicates; a low-voltage connection chamber to which a low-voltage cable drawn from the electric device main body communicates; and a tap changer accommodating a load tap changer. A chamber, a pressurizing device for applying pressure to the medium in response to a pressure change of the insulating medium inside the sealed container, and an impact gas pressure relay device for detecting an impact gas pressure at the time of an accident; In response to the pressure fluctuation of the internal insulating medium, a pressure higher than the atmospheric pressure is applied to the medium, and the shock gas pressure relay device detects the shock gas pressure at the time of an accident, thereby protecting the electrical equipment. In the method for protecting electrical equipment described above, the pressurizing device communicates with the high-voltage cable chamber, the low-voltage connection chamber, and the load tap changer accommodating chamber, and these chambers are maintained at a pressure higher than the atmospheric pressure. In addition, the impact gas pressure at the time of the accident is detected in each chamber, and the point of the accident is determined based on the amount and time at which the impact gas pressure is transmitted to other gas chambers to protect the equipment. .

That is, in the electric equipment thus formed, the pressurizing device is connected to the high-voltage cable chamber, the low-voltage connection chamber, and the load tap changer accommodation chamber via the connection pipe, and each chamber is connected. Since it is formed to have a pressure equal to or higher than the atmospheric pressure, and each of these chamber units is provided with an impact gas pressure relay for detecting accidents, a pressurizing device for pressurizing the nonflammable liquid of electric equipment is provided. As a part, the load tap change chamber and the high pressure cable chamber can be used together, so that the size of the pressurized and sealed tank can be reduced.
An accident in one's own room can be reliably detected by a relay installed in one's own room, and it is possible to easily determine a portion where an accident has occurred.

That is, the gas flow velocity is determined by the connecting pipes connecting the respective chambers, and the volume of gas flowing into and out of the gas chambers is determined. Therefore, the gas pressure rise in each gas chamber can be easily calculated. By adjusting the thickness and length of the piping or by providing a throttle valve, it is easy to adjust the inflow and outflow of gas pressure at the time of an accident, and at the same time, it is possible to easily identify the part where the accident has occurred based on the elapsed time. is there.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. 1 and 2 show one embodiment of the electric equipment. FIG. 1 is a side view, and FIG. 2 is a system diagram viewed from above. In the figure, reference numeral 1 denotes a sealed container, which is provided with an electric device main body accommodating chamber 1a and a load tap changer accommodating chamber 6. Reference numeral 8 denotes a high-pressure cable chamber to which a high-voltage cable drawn from the electric device main body communicates, 9 denotes a low-pressure connection chamber to which a low-voltage cable drawn from the electric device main body communicates, and 7 denotes a pressurized sealed tank.

The electric equipment main body accommodating chamber 1a is filled with a nonflammable liquid (perfluorocarbon liquid) 5, and an iron core 2 is provided.
And the electric device main body 4 comprising the winding 3 and the non-flammable liquid 5
It is housed so as to be immersed in.

The load tap changer accommodating chamber 6, the high-pressure cable chamber 8, and the low-pressure connecting chamber 9 are connected to the pressurized and sealed tank 7 via the connecting pipe 15, and the nonflammable insulating gas 10 stored in the container is connected. The non-flammable liquid 5 for immersing the electric device body 4 is formed to be pressurized. That is, the insulating performance of the nonflammable liquid is improved by pressurizing the nonflammable liquid 5.

Further, a connecting pipe 1 for connecting the respective chambers is provided.
In the middle of 5, a flow regulating device for regulating the gas flow, that is, a throttle valve 16, is provided as shown in FIG. In each of these rooms, an impact gas pressure relay 11 for detecting an accident is provided for each room.

As described above, since the nonflammable insulating gas 10 in each of these chambers is connected by the connection pipe 15, for example, when a ground fault occurs in the high-pressure cable chamber 8, the gas pressure rises. 15 through the shock gas pressure relay 1
1, the throttle valve 16 is arranged in the middle of these connection pipes 15 so that the gas inflow and outflow can be adjusted so that the accident portion can be easily identified.

Further, in this case, the thickness and length of the connection pipe connecting the load tap change-over chamber and the cable chamber used as the pressurizing device may be adjusted. By this adjustment, the gas flow velocity is naturally determined and the volume of gas flowing into and out of the gas chambers is determined, so that the gas pressure rise in each gas chamber can be calculated, and the impact gas can be calculated by properly escaping the pipe thickness and length. The pressure rise can be adjusted. Of course, by providing a throttle valve or a device that can be adjusted from the outside on the connecting pipe to be connected, it is easier to adjust the inflow and outflow of gas pressure in the event of an accident. It will be easier. In addition, it is also possible to determine the fault point by forming the connection pipe connecting the main gas chambers to the relay for fault detection.

The pressure rise P of the gas chamber at the time of the accident is expressed by the following equation.

[0020]

P = C ₁ × I _S t / V (1) where P: pressure rise (kgf / cm ² ) C ₁ : coefficient 0.2 to 0.35 I _S : arc current (kA) t : Arc current conduction time (ms) V: gas chamber volume Further, gas chamber 1R, gas chamber 2R, and gas chamber 3 in FIG.
The pressure rise in the gas chamber when the inflow and outflow of R gas are considered is expressed by the following equation (2).

[0021]

(Equation 2)

From the above equations (3) and (4), the pressure rise in the gas chambers depends on the thickness and length of the pipe, the gas flow velocity is determined, and the volume of gas flowing into and out of the gas chambers is determined. The gas pressure rise can be calculated. Further, the rise of the impact gas pressure can be adjusted by properly selecting the thickness and length of the pipe.

As described above, with this electric equipment, the on-load tap switching accommodation chamber and the high pressure cable chamber can be used together as a part of the pressurizing device for pressurizing the nonflammable liquid of this kind of electric equipment. In addition, the size of the pressurized and sealed tank can be reduced, so that the height of the electrical equipment can be reduced, and the height of the construction building of the urban underground substation in which this type of electrical equipment is installed can be reduced. In addition, substation construction costs can be reduced.

At the same time, the thickness and length of the connecting pipe connecting the load tap switching chamber and the high pressure cable chamber in which the nonflammable insulating gas is filled are adjusted, and a throttle valve is provided in the middle of the pipe. Is installed, the rise in the shock gas pressure can be adjusted, so that the gas pressure rise time can be determined, and the location where the accident has occurred can be easily determined.

[0025]

As described above, according to the present invention, it is possible to reduce the size of the pressurized and sealed tank of a non-combustible electric device in which a non-combustible liquid is used as an insulating medium, and the pressurized gas compartment may be damaged. It is possible to obtain electrical equipment that can easily detect time and determine an accident point.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing one embodiment of an electric equipment facility of the present invention.

FIG. 2 is a system diagram showing an embodiment of the electric equipment of the present invention.

FIG. 3 is a piping diagram of a conventional electrical equipment facility.

FIG. 4 is a piping system diagram in which a throttle valve is installed in the piping of the electric equipment of the present invention.

FIG. 5 is a system explanatory diagram for explaining gas pressure inflow and outflow to a gas chamber.

[Explanation of symbols]

1. Sealed container (Electric equipment main body accommodation room) 2. Iron core 3.
Winding, 4 ... Electrical equipment main body, 5 ... Non-flammable liquid (perfluorocarbon liquid), 6 ... Tap changer accommodation room at load, 7 ... Pressurized and sealed tank, 8 ... High pressure cable room, 9 ... Low pressure connection room, 1
0: Non-combustible insulating gas (SF6 gas), 11: Impact gas pressure relay, 12: Tap changer under load, 13: Compound meter, 1
4 ... Electrical equipment monitoring panel, 15 ... Connection piping, 16 ... Throttle valve.

Claims (8)

[Claims] A sealed container accommodating an insulating medium and an electric device main body immersed in the medium; a high-voltage cable chamber through which a high-voltage cable drawn from the electric device main body communicates; A low-voltage connection chamber to which the drawn low-voltage cable communicates, and a tap changer accommodating chamber in which a load tap changer is housed, in the sealed container, in response to pressure fluctuation of the insulating medium inside the sealed container. In an electric equipment having a pressurizing device for applying a pressure equal to or higher than the atmospheric pressure to the medium, the pressurizing device is connected to a high-pressure cable chamber, a low-pressure connecting chamber, and a load tap changer accommodating chamber by connecting pipes. An electric equipment system wherein each chamber is formed to have a pressure higher than the atmospheric pressure, and an impact gas pressure relay for detecting an accident is provided for each of these chambers. 2. A sealed container accommodating an insulating medium and an electric device main body immersed in the medium, a high-voltage cable chamber through which a high-voltage cable drawn from the electric device main body communicates, A low-voltage connection chamber to which the drawn low-voltage cable communicates, and a tap changer accommodating chamber in which a load tap changer is housed, in the sealed container, in response to pressure fluctuation of the insulating medium inside the sealed container. In an electric equipment having a pressurizing device for applying a pressure equal to or higher than the atmospheric pressure to the medium, the pressurizing device is connected to a high-pressure cable room, a low-pressure connection room, and a load tap changer housing room via a connection pipe; These chambers are formed so as to have a pressure higher than the atmospheric pressure, and an impact gas pressure relay for accident detection is provided for each of these chambers, and the gas flow rate is set in the connection pipe. Electrical equipment facility being characterized in that so as to provide a flow control device for integer. 3. The electric equipment according to claim 1, wherein said electric equipment main body is a stationary inductor, said insulating medium is a perfluorocarbon liquid, and said medium for applying pressure is SF6 gas. 4. The electric equipment according to claim 2, wherein the flow rate adjusting device for adjusting the gas flow rate is a throttle valve. 5. A sealed container accommodating an insulating medium and an electric device main body immersed in the medium, a high-voltage cable chamber through which a high-voltage cable drawn from the electric device main body communicates, and A low-voltage connection chamber to which the drawn low-voltage cable communicates, a tap changer accommodating chamber accommodating a load tap changer, and a pressure applied to the medium in response to a pressure change of the insulating medium inside the sealed container. A pressurizing device, comprising an impact gas pressure relay device for detecting an impact gas pressure at the time of an accident, applying a pressure higher than the atmospheric pressure to the medium in response to a pressure fluctuation of the insulating medium inside the sealed container, In a method for protecting electrical equipment, the impact gas pressure relay detects an impact gas pressure at the time of an accident and protects the electrical equipment. By communicating the pre-load tap changer housing chamber, as well as operated keep these chambers so that the above atmospheric pressure,
A method for protecting electrical equipment, wherein the impact gas pressure at the time of the accident is detected for each chamber, and the point of the accident is determined from the amount and time at which the impact gas pressure is transmitted to other gas chambers. 6. The amount of impact gas pressure transmitted to other gas chambers in the middle of each communication section which communicates the pressurizing device with the high pressure cable chamber, the low pressure connection chamber, and the load tap changer housing chamber. 6. The method for protecting electrical equipment according to claim 5, further comprising adjusting means for adjusting time. 7. The flow rate adjusting means is adjusted by adjusting a size or a length of a communication path communicating the two chambers.
The method for protecting electrical equipment described in the item. 8. The method for protecting electrical equipment according to claim 6, wherein said flow rate adjusting means is a throttle valve.