JPH10174278A - Electrical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical equipment that can prevent fire from occurring because of the rupture of a capacitor and an oil leakage in advance. SOLUTION: An electric wire 11 is wound on the side peripheral surface of a capacitor 3, and an electrical signal from a power supply 12 is transferred by the electric wire 11. When the capacitor 3 fails and is inflated, the electric wire 11 is cut off and a detection circuit 13 detects that no electrical signal arrives, thus detecting the failure of the capacitor 3 before the rupture of the capacitor 3 and oil leakage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric device using an oil-filled capacitor, and more particularly to a high-voltage electric device such as a semiconductor valve used for DC power transmission or a static var compensator (SVC).

[0002]

2. Description of the Related Art DC power transmission and static var compensators (S
A semiconductor valve using a thyristor, a GTO or the like used in a VC) or the like is composed of a semiconductor switching element such as a thyristor or a GTO and its peripheral circuit, and the semiconductor switching elements are connected in series / parallel by a required voltage and current. It is composed. In particular, in a thyristor valve or the like used for DC power transmission or the like, a large number of thyristors are connected and used, and thus are divided into units called thyristor modules.

FIG. 10 shows a circuit example of a conventional thyristor valve module. In the figure, 1 is a thyristor, 2 is a resistor, and 3 is a capacitor. A circuit in which the resistor 2 and the capacitor 3 are connected in series is a so-called snubber circuit connected in parallel with the thyristor 1. Further, the reactors 4a and 4b are connected in series with the thyristor 1, and the thyristor 1 is connected by these reactors.
Prevents inrush current when is fired. The resistor 5 is a DC voltage dividing resistor and balances the voltage applied to the thyristors 1 connected in series. The voltage detection board 6 is for detecting the state of the thyristor 1,
It has a resistor 6a connected in series with the resistor 5 and having a smaller resistance value than the resistor 5, and a light emitting diode 6b that emits light when a voltage is applied to the resistor 6a. A switching element that conducts when a predetermined voltage is applied is used as the light emitting diode 6b when this element conducts.
However, it may be configured to emit light. A signal indicating the state of the thyristor 1 detected by the voltage detection board 6, that is, an optical signal from the light emitting diode 6b is transmitted to a control device (not shown) via the optical cable 7. In other words, the resistor 6a (or the switching element 6)
By detecting the voltage signal according to a), it is detected that a voltage is applied to the thyristor 1, which is a necessary condition for firing the thyristor. This voltage signal is also used for detecting a short-circuit failure of the thyristor 1. If no voltage is applied even when the thyristor 1 is not fired, it is determined that the thyristor 1 has a short-circuit failure. .

FIG. 11 shows an example of the arrangement of elements constituting a module of the thyristor valve. Although the optical cable 7 is not shown in the figure, it is assumed that the optical cable 7 is disposed above the voltage detection board 6 and perpendicular to the paper.

In such a conventional thyristor valve, the capacitor 3 used in the snubber circuit generally uses oil as an insulator, and when a fire occurs due to an abnormality in the capacitor, this oil is used. There was a possibility that the fire would spread to the fire of the entire module or thyristor valve as well as the combustion of the condenser. By the way, as is well known in the past, when an abnormality such as a pinhole existing inside the capacitor becomes large or an element inside the capacitor is partially short-circuited due to the entry of foreign matter, the capacitor is ruptured or oil-filled. Before the leak, the capacitor case expands. Therefore,
Conventionally, the presence or absence of expansion of the capacitor is visually checked by periodic inspection, and if the capacitor has swelled, the capacitor is replaced to prevent the capacitor from exploding or leaking oil.

[0006]

However, in the conventional method of visually detecting the expansion of the capacitor, an oversight may occur, and if the inspection is performed in accordance with the periodic inspection cycle every several years, the periodic inspection is not performed. It may not be found in the case where it suddenly expands in a period shorter than the period of the above, leading to rupture or oil leakage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a means for constantly monitoring and detecting swelling of a capacitor, and can prevent the occurrence of a fire due to rupture of a capacitor or oil leakage. The purpose is to provide.

[0008]

An electric device according to the present invention is provided with an oil-filled capacitor and at least a part of a side surface of the capacitor in contact with or in close proximity to the capacitor. Signal transmission means for
Means for detecting a predetermined change in the signal transmitted by this means.

According to this configuration, since deformation such as expansion of the capacitor can be detected, the apparatus can be stopped or the capacitor can be replaced before the capacitor is ruptured or oil leaks. It is possible to prevent the occurrence of a fire due to.

[0010] Further, the electric device of the present invention is provided with a plurality of oil-filled capacitors and at least a part of each side surface of the plurality of capacitors in contact with or in proximity to each other,
A plurality of signal transmission means whose transmission characteristics change due to deformation of each of the capacitors; a means for connecting each of the plurality of signal transmission means in series; and a signal transmission means connected in series by this means. Means for detecting a predetermined change in the signal transmitted by the means.

According to this configuration, even if any one of the plurality of capacitors is deformed, a predetermined change in the signal caused by the deformation can be detected by one detecting means. Fire can be prevented from occurring.

The signal transmission means may be constituted by an electric wire which is provided in contact with at least a part of the side surface of the capacitor and which is cut by deformation of the capacitor. Furthermore, by using an optical fiber cable as the signal transmission means, it can be used in high-voltage electrical equipment.

A new circuit for generating an optical signal transmitted by an optical fiber cable is provided by using a signal that detects the state of a semiconductor switching element as an optical signal transmitted by the optical fiber cable. Thus, it is possible to detect the deformation of the capacitor without adding a new circuit for detecting a change in the optical signal transmitted.

Further, since the optical fiber cable has at least a part of the protective film removed, the force applied to the optical fiber cable due to the deformation of the capacitor can be concentrated at one place, and the slight amount of the capacitor can be reduced. Deformation can also be detected.

Further, the signal transmission means is an optical fiber cable connected to a connector provided in contact with at least a part of the side surface of the capacitor, so that the light quantity of the optical signal transmitted through the connector is reduced by the deformation of the capacitor. , And the deformation of the capacitor can be detected by detecting this.

Further, if the signal transmitting means is an optical signal emitting means and an optical signal receiving means provided opposite to a reflecting surface formed on at least a part of the side surface of the capacitor,
Due to the deformation of the capacitor, the amount of the light signal radiated from the radiating means received by the light receiving means is reduced,
By detecting this, the deformation of the capacitor can be detected.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following drawings, the same parts or corresponding parts are denoted by the same reference numerals. (First Embodiment) FIG. 1 shows a main part of a first embodiment of an electric apparatus according to the present invention. In the figure, reference numeral 3 denotes a capacitor constituting a snubber circuit. An electric wire 11 is wound around a side peripheral surface of the capacitor 3, an electric signal from a power supply 12 is transmitted by the electric wire 11, and the signal is detected by a detection circuit 13. deep. When the capacitor 3 expands due to an abnormality in the capacitor 3, the electric wire 11 is cut. Therefore, the detection circuit 13 detects that the electric signal has disappeared, thereby detecting the abnormality of the capacitor 3. Therefore, when the abnormality is detected, the apparatus can be stopped by the abnormality detection signal output from the detection circuit 13 or the capacitor 3 can be replaced by receiving an alarm by the abnormality detection signal. It is possible to prevent a fire due to an oil leak from occurring.

(Second Embodiment) Next, FIG. 2 shows a main part of a second embodiment of the electric equipment according to the present invention. In this embodiment, the electric wire 11 in the first embodiment is
An optical transmission circuit 22 and an optical reception circuit 23 are provided in place of the optical fiber cable 21 which is an insulator. When an abnormality occurs in the capacitor 3 and the capacitor 3 expands, the optical fiber cable 21 is cut and an optical signal is transmitted. By detecting the disappearance, the abnormality of the capacitor 3 is detected. By using the optical fiber cable 21, it can also be used for high-voltage equipment that requires a high degree of insulation. In arranging the optical fiber cable 21 so as to be in contact with the capacitor 3, if the optical fiber cable 21 can be wound as in the first embodiment, the optical fiber cable 21 may be wound.
If it cannot be wound and used due to physical restrictions such as bending strength, the portion in contact with the capacitor 3 may be configured as shown in FIG. 3, for example.

In FIG. 1A, the portion of the optical fiber cable 21 that is in contact with the capacitor 3 is fixed with an adhesive 31. The portion except for the vicinity of the center of one side of the capacitor 3 is coated with the adhesive 31. It is fixed. With such a configuration, the optical fiber cable 21 is cut in the vicinity of the center where the optical fiber cable 21 exerts the most force due to the expansion of the capacitor 3, and the expansion of the capacitor 3 can be effectively detected.

FIG. 2B shows the optical fiber cable 21 in which the portion in contact with the capacitor 3 is fixed with an adhesive tape 32 instead of the adhesive 31. The operation and effect of FIG. It is almost the same as the case.

FIG. 2C shows a case where the optical fiber cable 21 is fixed to columns 33 provided at both ends of one side surface of the capacitor 3 with bands 34. Even with such a configuration, since the disconnection is caused by the expansion of the capacitor 3, the expansion of the capacitor 3 can be detected.

Third Embodiment FIG. 4 shows a main part of a third embodiment of the electric equipment according to the present invention. The first or second
In the embodiment described above, a case is described in which an electric wire or an optical fiber cable is connected to one capacitor. However, generally, a plurality of capacitors exist in a thyristor valve module. in this case,
Wire 11 and power supply 1 for each capacitor
2. Instead of providing the detection circuit 13 or the optical fiber cable 21, the optical transmission circuit 22, and the optical reception circuit 23, FIG.
As shown in (a), one electric wire 11 is connected to a plurality of capacitors 3,
.., One set of the power supply 12 and the detection circuit 13 is prepared, or one optical fiber cable 21 is connected to a plurality of capacitors 3, 3,... As shown in FIG. The winding may be performed one after another, and only one set of the optical transmitting circuit 22 and the optical receiving circuit 23 may be prepared. With such a configuration, the plurality of capacitors 3,
3, any one of the capacitors becomes abnormal and expands, and one electric wire 11 or optical fiber cable 21, one set of power supply 12 and detection circuit 13, or one set of optical transmission circuit 22 and optical reception circuit 23 Since this can be detected, it is economical and maintenance and inspection are easy.

(Fourth Embodiment) Next, a fourth embodiment of the electric apparatus according to the present invention will be described. As described in the section of the prior art, generally, in a thyristor valve module, a signal indicating the state of the thyristor 1 detected by the voltage detection board 6 in FIG.
Is transmitted to a control device (not shown) via the optical fiber cable 7 and the thyristor 1
Has been confirmed. Therefore, the optical fiber cable 7 for transmitting a signal that detects the state of the thyristor 1
To the optical fiber cable 21 in the second embodiment.
If the optical fiber cable 7 is configured to be in contact with the capacitor 3, the abnormality of the capacitor 3 can be detected without adding a new circuit. In this case, no signal is sent to the control device in the case of an abnormality such as a short-circuit failure of the thyristor 1 or in the case of an abnormality in the capacitor 3.
What is necessary is just to treat it as what has an abnormality in one of the capacitors 3.

(Fifth Embodiment) FIG. 5 shows a fifth embodiment of the electric apparatus according to the present invention. In this embodiment, the optical fiber cable 2 of the second embodiment is used.
Part (b) of FIG. 1 shows a part of the protective film 21S of the optical fiber cable 21 (see FIG. (A) showing a cross section of the optical fiber cable 21). As such, it has been removed. With such a configuration, the force exerted by the expansion of the capacitor 3 can be concentrated on the portion of the optical fiber cable 11 from which the protective film has been removed, and even a slight deformation of the capacitor 3 can be detected. Damage and oil leakage can be prevented.

(Sixth Embodiment) As shown in FIG. 6, in a sixth embodiment of the electric apparatus according to the present invention, a part of the portion of the optical fiber cable 21 in contact with the capacitor 3 in the second embodiment, for example, A connector 61 is provided near the center of one side of the capacitor. This connector 6
For example, the method of providing 1 can be easily realized by cutting the optical fiber cable 21 and providing the elastic cylindrical connector 61 so as to surround the outer periphery of the optical fiber cable 21 with two cut surfaces facing each other. it can. When this connector 61 is deformed, this connector 61
The light amount of the optical signal transmitted from one optical fiber cable 21 to the other optical fiber cable 21 via the optical fiber cable 21 decreases. That is, before the deformation of the connector 61 as shown in FIG. 7A, a part of the optical signal transmitted from one optical fiber cable 21 to the other optical fiber cable 21 is changed to the connector 61 as shown in FIG. Is not transmitted to the other optical fiber cable 21 after the deformation, the light amount of the transmitted optical signal decreases. Therefore, connector 6
By providing 1, it is possible to detect that the condenser 3 has expanded by detecting a decrease in the amount of light.

According to the sixth embodiment, even when the capacitor 3 expands, the electric wire or the optical fiber cable is not cut as in the first to fifth embodiments. When the expansion is detected, the electric wire 11 and the optical fiber cable 21 do not need to be replaced, and only the condenser 3 needs to be replaced. Therefore, it is economical and the maintenance and inspection are easy.

(Seventh Embodiment) In a seventh embodiment of the electric equipment according to the present invention, as shown in FIG.
A mirror surface is formed on at least a part of one side surface, for example, near the center. A radiating circuit 81 which emits an optical signal having high linearity such as a laser in the vicinity of the radiating circuit 81 and the radiating circuit 81
A light receiving circuit 82 for receiving an optical signal radiated from and reflected by the mirror surface is arranged to face the mirror surface. When the capacitor 3 is normal, almost all of the optical signal radiated from the radiation circuit 81 and reflected by the mirror surface is received by the light receiving circuit 82 as shown in FIG.
When the condenser 3 expands and the mirror surface becomes convex, the amount of light received by the light receiving circuit 82 decreases as shown in FIG. 9B. Accordingly, the expansion of the capacitor 3 can be detected based on the decrease in the amount of received light.

According to the seventh embodiment, there is no need to install the electric wire 11 or the optical fiber cable 21 in direct contact with the capacitor 3 as in the first to sixth embodiments, so that it is not necessary to replace the capacitor. Maintenance can be easily performed.

[0029]

As described above, according to the present invention, it is possible to detect an abnormality in a capacitor before the capacitor ruptures or leaks oil, so that a fire due to rupture of the capacitor or oil leak can be prevented. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an exemplary perspective view showing a main part of an electric device according to a first embodiment of the present invention;

FIG. 2 is an exemplary perspective view showing a main part of an electric device according to a second embodiment of the present invention;

FIG. 3 is a diagram illustrating details of a portion of the optical fiber cable in contact with a capacitor according to the second embodiment of the present invention.

FIG. 4 is an exemplary plan view showing a main part of an electric device according to a second embodiment of the invention.

FIG. 5 is a view for explaining a portion of the optical fiber cable according to a fifth embodiment of the present invention from which a protective film is removed.

FIG. 6 is a view for explaining an optical fiber cable connector according to a sixth embodiment of the present invention.

FIGS. 7A and 7B are diagrams showing transmission states of optical signals before and after deformation of the connector shown in FIGS.

FIG. 8 is an exemplary perspective view showing a main part of an electric device according to a seventh embodiment of the present invention; .

FIG. 9 is a diagram showing a transmission state of an optical signal before and after deformation of a mirror surface of the capacitor shown in FIG. 8;

FIG. 10 is a circuit diagram showing an example of a conventional thyristor valve module.

FIG. 11 is a plan view showing an arrangement example of elements constituting a conventional thyristor valve module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Thyristor 3 ... Capacitor 6 ... Voltage detection board 7, 21 ... Optical fiber cable 11 ... Electric wire 12 ... Power supply 13 ... Detection circuit 22 ... Optical transmission circuit 23 ... Optical reception circuit 31 ... Adhesive 32 ... Adhesive tape 33 ... Post 34 ... Band 61: Connector 81: Radiation circuit 82: Light receiving circuit

Claims (8)

[Claims] An oil-filled capacitor, a signal transmission means provided in contact with or at least close to at least a part of a side surface of the capacitor, and a signal transmission characteristic changed by deformation of the capacitor; Means for detecting a predetermined change in the signal. 2. A plurality of oil-filled capacitors and at least a part of a side surface of each of the plurality of capacitors are provided in contact with or in close proximity to each other, and the deformation of each of the capacitors changes the transmission characteristic of each signal. A plurality of signal transmitting means, a means for connecting each of the plurality of signal transmitting means in series, and a means for detecting a predetermined change in a signal transmitted by the signal transmitting means connected in series by this means. An electrical device comprising: 3. The signal transmission means according to claim 1, wherein said signal transmission means is an electric wire provided in contact with at least a part of a side surface of said capacitor and cut by deformation of said capacitor. Electrical equipment. 4. The optical fiber cable according to claim 1, wherein said signal transmission means is an optical fiber cable provided in contact with at least a part of a side surface of said capacitor and cut by deformation of said capacitor. Electrical equipment as described. 5. A semiconductor switching element, an oil-filled capacitor, and an optical signal which is provided in contact with at least a part of a side surface of the capacitor, and wherein a transmitted optical signal is interrupted or transmitted by a deformation of the capacitor. An optical fiber cable in which the amount of light changes, and means for detecting a predetermined change in an optical signal transmitted by the optical fiber cable, wherein the optical signal transmitted by the optical fiber cable is a signal obtained by detecting the state of the semiconductor switching element. An electrical device characterized by the following. 6. The electric apparatus according to claim 4, wherein the optical fiber cable has at least a part of a protective film removed. 7. The optical fiber cable connected to a connector provided in contact with at least a part of a side surface of the capacitor, wherein the signal transmission means is an optical fiber cable connected to both ends of the connector due to deformation of the capacitor. 3. The electric device according to claim 1, wherein the light amount of the optical signal transmitted from one of the cables to the other changes. 8. The signal transmitting means comprises an optical signal emitting means and an optical signal receiving means provided to face a reflecting surface formed on at least a part of a side surface of the capacitor. The electric device according to claim 1, wherein an amount of an optical signal emitted from the emitting unit received by the light receiving unit changes.