JPH0716171U - Current transformer for gas-insulated electrical equipment - Google Patents

Abstract

(57) [Summary] [Purpose] For gas-insulated electrical equipment that is highly reliable without the risk of short circuits, can accurately detect the current flowing through the conductor, is easy to install, is simple in structure, and inexpensive. Provide a current transformer. [Structure] An optical fiber current sensor 6 is wound around a spacer 4 which is sandwiched between pipes 2 and 3 and through which a conductor 1 penetrates so as to interlink with the conductor 1. At this time, the optical fiber current sensor 6 is arranged inside the peripheral groove 4 a provided on the outer peripheral surface of the spacer 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a current transformer for gas insulated electrical equipment, which detects an electric current flowing through a conductor passing through a tube body of gas insulated electrical equipment (GIS) by using an optical fiber current sensor.

[0002]

[Prior art]

 FIGS. 4 (a) and 4 (b) are cross-sectional views of a portion around a current transformer of a gas-insulated electric facility equipped with a conventional current transformer for gas-insulated electrical facility. In FIG. 4, 21 is a conductor, and 22 and 23 are metal pipes surrounding the conductor 21, respectively. Reference numeral 24 denotes an insulating spacer interposed between the joints of the pipe bodies 22 and 23 and held between the pipe bodies 22 and 23. The conductor 21 penetrates through the support spacers while supporting the conductor 21 in an insulated state from the pipe bodies 22 and 23. The space inside the pipe body 22 and the space inside the pipe body 23 are airtightly separated to prevent the flow of the insulating gas. Numeral 25 is a fixing means such as a bolt and nut for connecting and fixing both flanges of the pipes 22 and 23 with the insulating spacer 24 sandwiched therebetween. Reference numeral 26 denotes, for example, an optical fiber current sensor wound directly around the conductor 21 at the position of the tube body 22, and both ends thereof are drawn out of the tube body 22 via airtight adapters 27 provided in the tube body 22, for example. After that, it is connected to the optical transceiver 28.

The current transformer for gas-insulated electrical equipment shown in FIG. 4 allows light to be incident on one end surface of the optical fiber current sensor 26 from the optical transmitter / receiver 28 and to be emitted from the other end of the optical fiber current sensor 26. By detecting the emitted light with the optical transmitter / receiver 28, the current flowing through the conductor 21 is detected. Here, the principle of current detection will be briefly described. When the optical fiber current sensor 26 is placed in a magnetic field parallel to the magnetic field, the polarization plane of the linearly polarized light propagating inside rotates. As the strength of the magnetic field increases, the rotation angle of the plane of polarization increases. Since the optical fiber current sensor 26 is wound so as to interlink the conductor 21, the magnetic field generated by the current flowing in the conductor 21 is parallel to the optical fiber current sensor 26. As a result, the plane of polarization of the linearly polarized light propagating in the optical fiber current sensor 26 rotates. Therefore, when the current flowing through the conductor 21 increases, the rotation angle of the plane of polarization of linearly polarized light increases.

[0004]

[Problems to be solved by the device]

 In the structure shown in FIG. 4, both ends of the optical fiber current sensor 26 wound around the conductor 21 are pulled out to the outside of the tube body 22 through the airtight adapter 27 provided in the tube body 22. Since the high-voltage side conductor 21 around which the optical fiber current sensor 26 is wound and the low-pressure side tube 22 provided with the airtight adapter 27 are connected by the optical fiber current sensor 26, the pressure resistance is increased. If it is not taken into consideration, the conductor 21 and the pipe 22 may be short-circuited, and the reliability was low.

Further, the temperature of the optical fiber current sensor 26 rises due to the heat generation of the conductor 21, and the temperature detection characteristic deteriorates the current detection sensitivity, so that the current of the conductor 21 cannot be accurately detected. In addition, it is necessary to process the pipe 22 to provide a mounting hole for the airtight adapter 27, which makes it difficult to install a current transformer for gas-insulated electrical equipment, and keeps the airtightness between the pipe 22 and the airtight adapter 27. However, there is a problem that the structure is complicated and expensive.

An object of the present invention is to provide a highly reliable transformer for gas-insulated electric equipment without the risk of short circuit or the like. Another object of the present invention is to provide a current transformer for gas-insulated electrical equipment capable of accurately detecting a current flowing through a conductor. Still another object of the present invention is to provide a current transformer for gas insulated electrical equipment which is easy to install, simple in structure and inexpensive.

[0007]

[Means for Solving the Problems]

 In the current transformer for gas-insulated electrical equipment of the present invention, an optical fiber current sensor is wound around a spacer sandwiched between pipes and through which a conductor penetrates so as to interlink with the conductor. At this time, in the optical fiber current sensor, a peripheral groove is formed on the outer peripheral surface of the spacer and is arranged inside the peripheral groove, or the optical fiber current sensor is embedded in the spacer. Moreover, it is desirable to cover the outer peripheral side of the optical fiber current sensor with an electromagnetic shield plate.

[0008]

[Action]

 According to the configuration of this invention, the current flowing in the conductor can be detected by the optical fiber current sensor provided in the spacer. Further, when the optical fiber current sensor is arranged inside the circumferential groove of the outer peripheral surface of the spacer, the optical fiber current sensor is located outside the tube body, and the optical fiber current sensor can be easily attached and detached.

If the optical fiber current sensor is embedded in the spacer, the optical fiber current sensor can be installed at the same time as the spacer is attached. Further, by covering the outer peripheral side of the optical fiber current sensor with an electromagnetic shield plate, it is possible to prevent an external noise magnetic field from affecting the optical fiber current sensor.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 (a) and 1 (b) are cross-sectional views of a gas-insulated electrical equipment equipped with a current transformer for gas-insulated electrical equipment according to the first embodiment of the present invention. In FIG. 1, 1 is a conductor, and 2 and 3 are metal tubular bodies surrounding the conductor 1. Reference numeral 4 denotes an insulating spacer interposed between the pipes 2 and 3 and held between the pipes 2 and 3, through which the conductor 1 penetrates, and the conductor 1 is supported while being insulated from the pipes 2 and 3. The space inside the tube body 2 and the space inside the tube body 3 are airtightly separated to prevent the flow of the insulating gas, and a peripheral groove 4a is formed on the outer peripheral surface. Reference numeral 5 is a fixing means such as a bolt and nut for connecting and fixing both flanges of the tubular bodies 2 and 3 with the insulating spacer 4 sandwiched therebetween. Reference numeral 6 denotes an optical fiber current sensor wound around the circumferential groove 4a on the outer peripheral surface of the insulating spacer 4 so as to interlink with the conductor 1. Both ends of the optical fiber current sensor are connected to the optical transceiver 7 outside the tubular body 2. There is. In FIG. 1A, the insulating spacer 4 is shown in appearance.

The current transformer for gas-insulated electrical equipment shown in FIG. 1 allows light to be incident on one end face of the optical fiber current sensor 6 from the optical transmitter / receiver 7 and from the other end of the optical fiber current sensor 6. By detecting the emitted light with the optical transmitter / receiver 7, the current flowing through the conductor 1 is detected. The principle of current detection is as described in the explanation of the conventional example.

According to this current transformer for gas-insulated electrical equipment, the optical fiber current sensor 6 is wound around the circumferential groove 4 a on the outer peripheral surface of the insulating spacer 4 so as to interlink with the conductor 1, and the current of the conductor 1 is supplied. Since the optical fiber current sensor 6 for current detection is located on the low-voltage side close to the tubes 2 and 3, it is electrically completely separated from the high-voltage side conductor 1 because it is detected. Since there are no parts for current detection inside the tubes 2 and 3 and nothing is attached, the conductor 1 on the high-voltage side and the tubes 2 and 3 on the low-voltage side are electrically designed as originally designed. The high-voltage side conductor 1 and the low-voltage side tubes 2 and 3 will not be short-circuited due to the provision of the optical fiber current sensor 6 for current detection. Is high.

Further, since the optical fiber current sensor 6 is wound around the peripheral groove 4a on the outer peripheral surface of the insulating spacer 4 and is away from the conductor 1 that generates heat, there is almost no temperature rise due to heat generation of the conductor 1. There is little change in the current detection sensitivity, and the current flowing in the conductor can be detected with high accuracy. Further, since the optical fiber current sensor 6 is wound around the outer peripheral surface of the insulating spacer 4 and is located outside the tube body, the optical fiber current sensor 6 is pulled out from the tube body 2 or 3 like the conventional example in order to pull out the optical fiber current sensor 6. It is not necessary to provide an airtight adapter mounting hole that penetrates through, and no special consideration is required to maintain airtightness. The current transformer for gas-insulated electrical equipment is easy to install, and the structure is simple and inexpensive.

Further, since the airtight adapter is not used, the light quantity loss until the light emitted from the optical transceiver 7 returns through the optical fiber current sensor 6 is small. Further, since the optical fiber current sensor 6 is provided outside the tubes 2 and 3, the optical fiber current sensor 6 can be easily attached to and detached from the spacer 4, and the maintenance work is easy.

FIG. 2 shows a sectional view of a current transformer for gas insulated electrical equipment according to a second embodiment of the present invention. In this current transformer for gas insulated electrical equipment, as shown in FIG. 2, a belt-shaped electromagnetic shield plate 8 is attached so as to cover the entire outer peripheral surface of the spacer 4 around which the optical fiber current sensor 6 is wound. Other configurations are similar to those of FIG. Reference numeral 9 is a fixing means such as a bolt and nut for attaching the electromagnetic shield plate to the spacer 4.

According to this embodiment, by providing the electromagnetic shield plate 9, the external noise magnetic field can be blocked, and the current flowing through the conductor 1 can be measured with higher accuracy. Other effects are similar to those of the first embodiment. FIG. 3 shows a sectional view of a current transformer for gas insulated electrical equipment according to a third embodiment of the present invention. This gas-insulated electrical equipment current transformer uses an annularly wound optical fiber current instead of using the spacer 4 as shown in FIG. 1 in which the optical fiber current sensor 6 is wound around the outer circumferential groove 4a. A spacer 12 is used in which the sensor 10 is embedded and a strip-shaped electromagnetic shield plate 11 is embedded so as to cover the outer circumference of the optical fiber current sensor 10. Other configurations are similar to those shown in FIG. Is.

Both ends of the optical fiber current sensor 10 are drawn out from the outer peripheral surface of the spacer 12 and connected to the optical transceiver 7. The current detection operation in this embodiment is similar to that in the previous embodiment. According to this embodiment, since the winding diameter of the optical fiber current sensor 10 is small and the optical fiber current sensor 10 can be brought close to the conductor 1, the current detection sensitivity can be increased and the optical fiber current sensor 10 can be used as the spacer 12. Since they are integrated, there is no need to wind and fix them around the spacer as in the first embodiment, and the current transformer for gas insulated electrical equipment can be installed in the gas insulated electrical equipment at the same time when the spacer 12 is installed. , It is easier to install the current transformer for gas-insulated electrical equipment. Besides, the same effects as those of the second embodiment can be obtained except the effect of easy maintenance.

In addition, in the configuration of FIG. 3, the electromagnetic shield plate 11 can be omitted.

[0019]

[Effect of device]

 According to the current transformer for gas-insulated electrical equipment of the present invention, the optical fiber current sensor is wound around the spacer, which is sandwiched between the pipes and through which the conductor penetrates, so as to interlink with the conductor. It is located on the low-voltage side close to the tube and is completely electrically separated from the high-voltage side conductor, and there are no parts for current detection inside the tube, and nothing is attached. Therefore, the high-voltage side conductor and the low-voltage side tube are kept electrically insulated as originally designed, and the high-voltage side conductor and the low-voltage side tube are the optical fiber current sensor for current detection. Since there is no short circuit due to the provision of the etc., the reliability is high.

Further, since the optical fiber current sensor is arranged in the peripheral groove of the outer peripheral surface of the insulating spacer and is away from the conductor that generates heat, there is almost no temperature rise due to heat generation of the conductor, and the change in current detection sensitivity does not occur. The number of currents flowing through the conductor can be accurately detected. Furthermore, since the optical fiber current sensor is wound around the outer peripheral surface of the insulating spacer and is located outside the tube, an airtight adapter that penetrates the tube is installed to pull out the optical fiber current sensor as in the conventional example. No holes are required, no special consideration is required to maintain airtightness, current transformers for gas-insulated electrical equipment are easy to install, and the structure is simple and inexpensive.

Further, if the optical fiber current sensor is wound around the outer circumference of the spacer, the optical fiber current sensor can be easily attached to and detached from the spacer, and the maintenance work can be easily performed. Also, if the optical fiber current sensor is embedded in the spacer, the winding diameter of the optical fiber current sensor is small and it can be made closer to the conductor, so the current detection sensitivity can be increased and the optical fiber current sensor Since the sensor is integrated with the spacer, there is no need to wind and fix it around the spacer, and a current transformer for gas-insulated electrical equipment can be installed in the gas-insulated electrical equipment at the same time as installing the spacer. It is easier to install the current transformer.

If an electromagnetic shield plate is provided so as to surround the outer circumference of the optical fiber current sensor, the current of the conductor can be detected without being affected by the noise magnetic field from the outside, and the conductor can be detected. The flowing current can be detected more accurately.

[Brief description of drawings]

1 (a) and 1 (b) are cross-sectional views of a current transformer for gas insulated electrical equipment according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a current transformer for gas-insulated electrical equipment according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a current transformer for gas-insulated electrical equipment according to a third embodiment of the present invention.

4A and 4B are cross-sectional views of an example of a conventional current transformer for gas-insulated electrical equipment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 conductor 2 tubular body 3 tubular body 4 spacer 4a peripheral groove 5 fixing means 6 optical fiber current sensor 7 optical transceiver

Claims (4)

[Scope of utility model registration request] 1. A current transformer for gas-insulated electrical equipment, comprising a spacer, which is sandwiched between pipes and through which a conductor penetrates, and an optical fiber current sensor wound around the spacer so as to interlink with the conductor. 2. A peripheral groove is formed on an outer peripheral surface of the spacer, and an optical fiber current sensor is arranged inside the peripheral groove.
Current transformer for gas-insulated electrical equipment as described. 3. The current transformer for gas-insulated electrical equipment according to claim 1, wherein an optical fiber current sensor is embedded in the spacer. 4. The current transformer for gas insulated electrical equipment according to claim 1, wherein the outer peripheral side of the optical fiber current sensor is covered with an electromagnetic shield plate.