JPH078106B2 - Optical method ground fault detector - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a busbar, a disconnector,
The present invention relates to an optical ground fault detection device for detecting a ground fault that occurs in a gas insulated switchgear in which a circuit breaker or the like is housed.

[Technical background of the invention] At substations or switchyards installed in large cities and coastal areas, due to reasons such as difficulty in obtaining land or measures against salt damage,
A gas-insulated switchgear is used in which the electrical equipment that composes a substation or switchgear is sealed with an insulating medium such as SF ₆ gas that has excellent insulation and arc extinguishing properties. Since this type of gas-insulated switchgear has three-dimensionally arranged breakers, disconnectors, and other required equipment, narrows the distance between the equipment, and is intended to greatly reduce the site area. The switch can be made significantly smaller than the air-insulated switchgear.

By the way, it is generally known that most of the failures of the transmission line are recoverable due to an arc or the like, and the permanent failures are only 10% of the total failure frequency. Therefore, in many cases, the power transmission can be continued as it is by instantaneously interrupting the broken power transmission line to make it non-voltage, and then transmitting power to this section again. In this way, when a ground fault occurs on the overhead line, the circuit breaker is once opened and then closed again so that the power failure can be kept in a short time. However, in the gas-insulated switchgear, when a ground fault occurs between the metal container and the busbar, it is impossible to recover the insulation again, so the ground fault is reliably detected and shut off. It was necessary to prevent a serious accident by issuing a signal to prevent the circuit from reclosing.

Conventionally used as a method of detecting the occurrence of a ground fault in such a gas-insulated switchgear is to detect decomposition products generated by an arc generated inside the metal container, or inside the metal container. There was a thing to investigate the fluctuation of the gas pressure of. However, the method as described above has a drawback that the arc generated by the ground fault cannot be detected unless the arc is at a certain level or higher, and the reliability is poor.

Therefore, in order to eliminate the drawbacks of the conventional ground fault accident detection device, a method of optically detecting a ground fault accident was devised. This is to detect the ground fault by directly receiving the arc light caused by the ground fault in the metal container by the light receiving sensor and guiding the optical signal to the O / E converter through the optical cable.

FIG. 3 shows the optical ground fault detection device described above. That is, a plastic cover 2 having a lens shape so as to have a light-collecting effect is covered on the tip of the light receiving sensor 1 for receiving the ground fault arc light, and the light receiving sensor is provided on the rear end of the light receiving sensor 1. An optical fiber cable 4 for transmitting the optical signal received at 1 to the O / E converter 3 is connected, and the other end of the optical fiber cable 4 converts the transmitted optical signal into an electric signal, and an external control panel. It is connected to the O / E converter that outputs to.

The optical ground fault detection device configured as described above is conventionally
As shown in FIG. 4, it was arranged on the side wall of the metal container 5. Then, the ground fault arc light 7 generated by the ground fault accident generated between the metal container 5 and the conductor 6 was detected.

[Problems of background art] However, although the optical ground fault detection device configured as described above has been attempted to widen the light collecting area by using a plastic lens, the incident light to the optical cable is There is a limit to the detection area of the arc light because there is a limit to the angle. Therefore, as shown in FIG. 4, when the optical ground fault detector is installed on the side wall of the metal container 5, the ground fault arc light 7 caused by the ground fault inside the metal container cannot be directly detected. However, the scattered light of the ground fault arc light 7 is detected, and the light intensity becomes extremely weak, so that there is a defect that the detection accuracy is poor and the reliability is lacking.

Further, as shown in FIG. 5, as the distance L between the position where the ground fault accident occurs and the installation position of the light receiving sensor 1 of the optical ground fault detection device becomes longer, the ground fault arc light 7 is generated inside the metal container 5. Since the number of reflections increases, and the intensity of scattered light weakens and it becomes difficult to detect. Therefore, as shown in FIG. 6, it is necessary to increase the number of installation locations of the optical ground fault detection device, which significantly increases the cost. The number of installations has increased and the installation process has become complicated.

[Object of the Invention] The present invention has been proposed in order to eliminate the drawbacks of the conventional optical ground fault detection device as described above, and an object thereof is to reduce the cost and to install the device easily. An object of the present invention is to provide a highly reliable optical ground fault detection device capable of improving the light receiving efficiency and reliably detecting the occurrence of a ground fault accident.

[Summary of the Invention] In an optical ground fault detection device of the present invention, a light receiving sensor is provided for each bent portion of a tubular bus bar in a metal container on a surface perpendicular to the longitudinal direction of the tubular bus bar in the longitudinal direction. By doing so, it is possible to receive the ground fault arc light directly or with a small number of reflections due to the ground fault accident occurring inside the metal container,
The detection is performed in each longitudinal direction.

[Embodiment of the Invention] An embodiment of the present invention will be specifically described below with reference to FIG. The same members as those of the conventional type shown in FIGS. 3 to 6 are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 1, in the present embodiment, the light receiving sensor 1 of the optical ground fault detecting device is arranged on a surface perpendicular to the longitudinal direction of the tubular bus bar for each bent portion of the tubular bus bar. . Also,
These light receiving sensors 1 are arranged in the respective longitudinal directions of the tubular bus bar.

That is, the ground fault arc light in the A direction is detected by the optical ground fault detector a, the ground fault arc light in the B direction is detected by the optical ground fault detector b, and the ground fault arc light in the C direction is detected by the optical ground fault detector. Detected by device c.

In the optical ground fault detection apparatus of the present embodiment having such a configuration, the ground fault arc light 7 due to the ground fault accident generated inside the metal container 5 is reflected directly or several times from the longitudinal direction of the metal container 5. Since the light can be received by the number of times, the intensity of the ground-fault arc light 7 is not weakened, and there is no fear of missed detection.

Further, since one light receiving sensor 1 corresponds to each longitudinal direction, the place where the ground fault arc light is generated can be surely specified.

Further, since each light receiving sensor 1 is provided with the surface perpendicular to the longitudinal direction, the installation process can be simplified.

Further, as shown in FIG. 2, a microphone 10 for detecting a sound signal or a pressure gauge 11 for detecting a pressure fluctuation signal is arranged on the same surface as the light receiving sensor arranged at the end of the metal container.
By providing the fault location function that can determine the location of the ground fault accident by reading the time difference between the ground fault light detected by the light receiving sensor and the sound signal or pressure fluctuation signal sensed by the microphone or pressure gauge. good.

EFFECT OF THE INVENTION According to the present invention, the light receiving sensor of the optical ground fault detecting device is
For each curved portion in the longitudinal direction of the tubular bus bar in the metal container,
Since the surface perpendicular to the longitudinal direction of the tubular bus bar is arranged in each longitudinal direction, it is possible to reliably detect the ground fault arc light generated inside the metal container, and at no cost, The installation process can be simplified. Also,
Since one light receiving sensor is associated with each direction, the place where the ground fault arc light is generated can be surely specified. Furthermore, by arranging a microphone or a pressure gauge on the same surface as the surface on which the light receiving sensor is arranged, it is possible to reliably determine the location of the ground fault accident.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the arrangement of the optical ground fault detecting device of the present invention, FIG. 2 is a sectional view showing another embodiment of the present invention, and FIG. 3 is an optical ground fault detecting device. Diagram showing the configuration of the device,
4 to 6 are sectional views showing the arrangement of a conventional optical ground fault detection device. 1 ... Light receiving sensor, 2 ... Plastic cover, 3 ... O / E converter, 4 ... Optical fiber cable, 5 ... Metal container, 6 ...
Conductor, 7 ... Ground fault arc light, 10 microphone, 11 ... Pressure gauge.

 ─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-54-116651 (JP, A) JP-A-55-58717 (JP, A) JP-A-51-14207 (JP, A) JP-A-54- 65348 (JP, A) Actually open Sho 61-88432 (JP, U) Japanese Patent Sho 41-9339 (JP, B1)

Claims (3)

[Claims] 1. A gas-insulated switchgear in which an electric device is housed in a bent metal container together with an insulating medium, and a ground-fault accident occurring in the gas-insulated switchgear is detected by a flashing light sensor. In an optical ground fault detection device that collects light with a lens and inputs it to an O / E conversion unit via an optical fiber to detect, the light receiving sensor, for each bent portion of the tubular bus bar in the metal container, the tubular bus bar An optical ground fault detection device, which is arranged on a surface perpendicular to the longitudinal direction of the optical fiber in the longitudinal direction. 2. The microphone according to claim 1, wherein a microphone for sensing a sound signal is disposed on the same surface of the metal container on which the light receiving sensor is disposed. Optical ground fault detector. 3. A pressure gauge for sensing a pressure fluctuation signal is disposed on the same surface of the metal container on which the light receiving sensor is disposed, as claimed in claim 1.
An optical ground fault detection device according to the item.