JPH02157670A - Internal fault detecting device - Google Patents

Abstract

PURPOSE:To display the position of a fault such as a ground fault and an interphase short circuit by detecting variations of bellows of two detection containers fixed at difference places of a gas container with a light signal and measuring their time difference. CONSTITUTION:If the fault such as the ground fault occurs at a position in a gas insulation opening/closing device 1, generated arc energy, etc., cause the temperature and pressure in this space to rise suddenly. The sudden pressure rise in the gas space is transmitted to a detection part 2R and a detection part 2L, the bellows 2a expand corresponding to the pressure rise, and when they reach the position of an optical fiber 5, the light signal emitted by a light emission part is projected from the end part of the optical fiber 5 and reflected by the projection and recess surfaces of the bellows. This reflected light enters a fault position display device 7 through the optical fiber 5 and is converted into an electric signal and a microcomputer specifies the fault position according to the time difference between the detection parts 2L and 2R.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an internal failure detection device for detecting ground faults, phase-to-phase short circuits, etc. in sealed electrical equipment such as gas-insulated switchgear.

[Prior Art] FIG. 4 is a cross-sectional view of an example in which an internal failure detection device as shown in Japanese Patent Application Laid-Open No. 58-115370 is attached to a gas-insulated switchgear.

In Fig. 4, when an internal failure such as a short circuit or a short circuit between phases occurs at position 4 in the gas insulated switchgear l,
Due to the injection of arc energy etc. caused by the failure, the 4 degree angle of this space rises rapidly, and the pressure rises accordingly. This rapid pressure increase in the gas space is transmitted to the detection section 2. FIG. 5 is an enlarged detailed cross-section of the detection part 2, in which the bellows 2a expands in response to an increase in pressure, and the contact of the microswitch 2b closes. Next, a display device 3 electrically connected to this contact point by an electric wire or the like shows an indication that the pressure has increased. This display makes it possible to detect failures in sealed electrical devices that cannot be directly monitored from the outside.

[Problems to be Solved by the Invention] Although it is possible to display the presence or absence of an internal failure in the conventional internal failure detection device l shown in FIG. The problem was that it could not be done.

Further, in the conventional example, since the operation of one point of the microswitch 2b is transmitted as an electric signal through an electric wire, there is also a problem that it is easily influenced by external noise and the like.

This invention was made in order to solve the above-mentioned problems, and provides a highly reliable internal failure detection device that is capable of locating the location of an internal failure and is not affected by noise etc. The purpose is to carry out.

[Means for Solving the Problems] An internal failure detection device according to the present invention includes a gas container in which a high voltage member is installed in a sealed gas space, a bellows communicating with the gas container, and a bellows connected to the gas container. a detection means that is enclosed and fixed to the gas container and sends out an optical signal corresponding to a pressure change detected by the movement of the bellows; and a detection means attached to the detection means to monitor fluctuations in the bellows or the rosette. an optical signal transmission means for transmitting an optical signal; and a bellows and optical signal transmission means fixed at different locations in the gas container and similar to the bellows and optical signal transmission means, and transmitting an optical signal similar to the optical signal. A fault location indicator having another detection means and a time measurement means for receiving an optical signal from an optical signal transmission means attached to each detection means and outputting a time difference and a sequential relationship between the optical signals of both detection means. It is equipped with the following.

[Operation] In the present invention, when a failure such as a ground fault or a short circuit between phases occurs inside the sealed gas container, a portion of the discharge energy becomes thermal energy within the gas container.

Therefore, the gas temperature at that location increases and the gas expands. The resulting pressure change is transmitted, and in the first detection container communicating with the gas container, for example, the bellows therein expands accordingly, making the surface of the bellows an anti-Q = 1 plane, changing the reflected light. and detect the reflected light. This reflected light is transmitted as an optical signal to the fault location indicator via the optical transmission line. Another second one with exactly the same bellows.
Similarly, an optical signal is transmitted from the detection container to the fault position indicator, and the time measuring means in the fault position indicator measures and calculates the difference between the two signals and the sequential relationship, and the fault position is displayed.

[Example] An example of the failure position indicator according to the present invention will be described with reference to FIGS. 1, 2, and 3.

FIG. 1 is a sectional view showing how an embodiment of the internal failure detection device according to the present invention is installed.

In Figure 1, when an internal failure such as a ground fault or a short circuit between phases occurs at position 4 in the gas-insulated switchgear l, the temperature of this space will rise rapidly due to the injection of arc energy etc. caused by the failure. , the pressure will increase accordingly. This rapid pressure rise in the gas space causes the detection unit 2
R and is transmitted to the detection unit 2L. FIG. 2 is an enlarged sectional view of the detection section 2R, and the same is true for the detection section 2L. In FIG. 2, when the bellows 2a expands in accordance with the increase in pressure and reaches the preset position of the optical fiber 5, the light emitting part (
An optical signal emitted from the optical fiber 5 (not shown) is emitted from the end of the optical fiber 5 and is reflected by the irregular surface of the bellows. This reflected light passes through the optical fiber 5 again, enters a light receiving section (not shown) in the failure position indicator 7, is converted into an electrical signal, and is transmitted to a microcomputer (not shown). This microcomputer constantly monitors the reflected light while controlling the light emitting section and the light receiving section, and transmits a failure signal when a sudden pressure increase is confirmed by the reflected light from the bellows 2a as described above. Similarly, a failure signal is also transmitted from the other detection section 2L.

In Fig. 3, as shown in Fig. 1, the fault location 4 is both detection parts 2L.
, 2R, the fault position indicator 7
It shows the signals from each detection unit transmitted to the time measuring means. Here, by measuring the time difference ΔT shown in the figure, the fault position can be determined, for example, at a distance of 1! from the detection unit 2R!
Obtained as IL2. The following formula % formula % l, 2: Distance tu from the detection section 2R to the fault position: Distance between the detection section 2R and the detection section 21□: Pressure propagation speed △T: T (2L) - T (2R) ( (see Figure 3).

By displaying this L2 on the fault location display 7, the location 4 of occurrence of an internal fault such as a ground fault or mutual short circuit is evaluated. The fault position is accurately detected by signals indicating the sequential relationship of the optical signals from both detection units.

In the above embodiment, the case of a gas insulated switchgear has been described, but the same effect can be achieved even with other sealed power equipment in which gas is sealed in a sealed space.

[Effects of the Invention] As described above, the internal failure detection device according to the present invention detects fluctuations in the bellows using an optical signal without using a microswitch having a mechanical contact built into the detection device. Therefore, it is not affected by noise etc.
A highly reliable failure detection signal can be obtained. Furthermore, since the two signals are processed and calculated by a fault position indicator having means for measuring the time difference between the detection signal for the same fault obtained by another detection container fixed at a different location of the gas container, the two signals are processed and calculated. It becomes possible to display the location where a failure such as a short circuit between phases has occurred.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an internal failure detection device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the detection unit 2 of FIG. 1.
Third. The figure shows signals transmitted from the detection units 2R and 2L in Figure 1 to the fault position indicator 7, Figure 4 is a sectional view of a conventional internal failure detection device, and Figure 5 shows the detection in Figure 4. FIG. 2 is an enlarged sectional view of part 2; In the figure, 1 is a gas insulated switchgear, 215.2R is a detection unit,
2a is a bellows, 5 is an optical fiber, and 7 is a fault position indicator. Figure 1

Claims (1)

[Scope of Claims] A gas container in which a high voltage member is installed in a sealed gas space, a bellows communicating with the gas container, a pressure change containing the bellows and fixed to the gas container and detected by the operation of the bellows. a detection means for transmitting an optical signal corresponding to the bellows; an optical signal transmission means for transmitting an optical signal from the detection means attached to the detection means for monitoring fluctuations in the bellows portion of the bellows; another detection means having a bellows and optical signal transmission means similar to the bellows and optical signal transmission means and sending out an optical signal similar to the optical signal; an optical signal of the optical signal transmission means attached to each detection means; an internal fault detection device comprising: a fault position indicator having time measuring means for receiving the optical signals and outputting the time difference and sequential relationship between the optical signals of both the detection means.