JP6872990B2 - Accident point rating device - Google Patents

Description

The present invention relates to an accident point locating device capable of assessing a gas section where an accident has occurred with a gas insulated switchgear.

The gas-insulated switchgear is configured by connecting a large number of gas compartments filled with gas, which is an insulating medium. Therefore, in the event of an accident such as a ground fault or short circuit, it is necessary to promptly find the gas section (container) where the accident occurred and repair or renew it. However, it is difficult to visually determine which pressure vessel the accident occurred in from the outside. Since the gas is overheated and expanded by the arc generated at the time of the accident, it is thought that the pressure vessel in which the accident occurred can be identified by monitoring the pressure in all the gas compartments constituting the gas-insulated switchgear. ..

In Patent Document 1, a strain gauge 9 is arranged on a partition partition wall 10 between a first gas chamber and a second gas chamber, which is provided outside the closed container 15 and communicates with the inside of the closed container. Detects internal accidents in gas insulation equipment by detecting the pressure difference in the gas chamber.

Japanese Patent Application Laid-Open No. 8-308046

However, since the internal accident detection device in the above patent document has a configuration in which the gas in the closed container is guided to the external pressure sensor through a pipe, a plurality of sealed portions are required for monitoring one closed container, and there is a risk of gas leakage. was there.

An object of the present invention is to provide an accident point locating device having a low risk of gas leakage.

The above purpose is to evaluate the accident point of a gas insulation switching device provided with a plurality of gas compartments for accommodating conductors, and the electric current is attached to each of the metal pipes constituting the gas compartment to cause distortion of the metal pipe. A strain detecting means for detecting, a current detecting means for detecting a current flowing through the conductor, a recording device for recording a signal of the strain detecting means, and a processing means for performing evaluation based on the signal of the recording device are provided. This is achieved by the processing means assessing the gas compartment, which is the point of failure, based on the signal recorded in the recording device when the current detected by the current detecting means exceeds a predetermined value.

According to the present invention, it is possible to provide an accident point locating device having a low risk of gas leakage.

It is a block diagram of the accident section point setting system. It is a figure which shows the attachment to the metal tube of a strain sensor. It is a figure which shows an example of the single-phase wiring diagram of a gas insulation switchgear. It is a figure which shows the flowchart of the accident point setting. It is a figure which shows the accident point display example on a monitor screen. It is a figure which shows the relationship of the instantaneous value of the current, the effective value, and the threshold value. It is a block diagram which shows the calculation method of the effective value from the instantaneous value of an electric current. It is a figure which shows the output of a strain sensor and the calculation result. It is a figure which shows the other flowchart of the accident point setting.

Hereinafter, an example of the embodiment will be described with reference to the drawings.

FIG. 1 is a system configuration diagram including a gas-insulated switchgear and an accident point locating device showing the present embodiment.

The gas-insulated switchgear is composed of a plurality of gas compartments 1a, 2a, 3a filled with an insulating gas, and a conductor 2 through which a high current flows. Here, the plurality of gas compartments 1a, 2a, 3a are composed of metal pipes 31a, 31b, 31c and insulating spacers 32a, 32b. In FIG. 1, spacers at both ends constituting 1a and 3a are omitted. In addition to the gas compartments 1a, 2a, and 3a, existing gas compartments are also omitted.

The accident point locator includes axial strain sensors 3a, 3b, 3c installed on the outer surfaces of the metal tubes 31a, 32b, 33c constituting the gas-insulated switching device, and circumferential strain for measuring the circumferential strain. The waveform recording unit 5, the waveform recording unit 5, and the communication line that can hold the instantaneous waveform of the signal from the sensors 4a, 4b, 4c, the current sensor 8 that detects the signal from these distortion sensors and the current of the conductor 2. It is composed of a processing unit 6 that is connected via 7 and performs diagnosis and evaluation. Here, it is assumed that the current sensor 8 is appropriately attached to all the ends of the unit of the gas-insulated switchgear as required. Since the strain sensor is not exposed to the insulating gas in the gas compartment, there is little failure or deterioration.

FIG. 2 shows an enlarged display of the distortion sensor mounting portion of FIG. The axial strain sensor 3b and the circumferential strain sensor 4b may be integrally configured.

FIG. 3 shows a double main bus system as an example of a single-phase connection diagram of a gas-insulated switchgear. In this example, there are 6 lines of drawers, and terminals N1 to N6 are connected to external equipment. Each line is provided with current sensors 8a to 8f for measuring the currents I1 to I6 flowing into the gas-insulated switchgear, and these signals are input to the waveform recording unit 5.

In FIG. 4, the setting of the accident point performed by the processing unit 6 will be described with reference to a flowchart. The processing unit 6 constantly monitors the current sensor signal 8. First, in the process S1, it is determined whether or not the measured current of the current sensor signal 8 exceeds the rated current.

Here, since the current measured by the current sensor signal 8 is the instantaneous value current i (t), as shown in FIG. 6, the i (t) is once converted into the effective value I (t), and the effective value is obtained. I (t) is the rated current 1p. u. Monitor if it exceeds. FIG. 7 shows a block diagram for calculating the effective value I (t) from the instantaneous value i (t) of the current. Using the instantaneous value i (t) and the instantaneous value i2 (t) that is 90 degrees out of phase with the electric angle, the effective value I (t) is calculated by the following equation.
(Number 1)
I (t) = √ (i (t) ^ 2 + i2 (t) ^ 2) / √2
When an accident occurs in the gas-insulated switchgear, the monitored current exceeds the rated current. If it exceeds the rated current, the process proceeds to the next process S2. If it does not exceed, the process does not proceed to S3.

In the process S2, the waveform recording unit 5 records the instantaneous waveforms of the signals from the axial strain sensors 3a, 3b, 3c ... And the axial strain sensors 4a, 4b, 4c ... Of all the gas compartments for a predetermined time.

In the process S3, a gas section exceeding a predetermined threshold value ε1 is specified from the axial strain sensors 3a, 3b, 3c ... In the gas compartment where the ground fault occurred due to the accident, the gas inside is overheated and expanded by the arc current, so that distortion occurs in the axial direction and the circumferential direction of the gas compartment based on the cylindrical shape. Therefore, by performing this process, it is possible to identify and narrow down the candidates for the gas section where the accident has occurred, and to reduce the false detection due to noise. Here, an accident means that a ground fault or a short circuit occurs due to foreign matter or gas leakage.

FIG. 8A describes the axial strain σ1. Here, it is assumed that a ground fault has occurred in the gas compartment 1b in FIG. Since the threshold value ε1 is exceeded for the adjacent gas compartments 1a and 1c in addition to the gas compartment 1b, the gas compartments 1a, 1b, 1c are selected from among many gas compartments and are candidates for the accident site. It becomes. If the peak value does not exceed the threshold value, it is excluded from the candidates.

If there is only one gas section that exceeds the threshold value ε1, it is evaluated as an accident point, and the process proceeds to process S6. Further, when there are a plurality of gas compartments exceeding the threshold value ε1, the gas compartment having the maximum peak value of the waveform may be evaluated as an accident point, and the process may proceed to S6.

In the process S4, the ratio σ1 / σ2 of the strain σ1 in the circumferential direction and the strain σ2 in the axial direction is calculated for the gas section that is a candidate for the accident point in the process S3. The strain σ2 in the circumferential direction is as shown in FIG. 8 (b). FIG. 8C shows an example of the calculation result of the ratio σ1 / σ2. The ratio of the gas compartment 1b where the accident has occurred is the largest.

In process S5, the gas compartment 1b having the largest ratio σ1 / σ2 is evaluated as an accident point.

In process S6, an accident occurred in the gas-insulated switchgear to be diagnosed from the information of the protection relay provided to operate the circuit breaker (FIG. 3) when an excessive current flows through the conductor 2. If it is specified, the process proceeds to the next process S7, and if the occurrence of the accident is not specified by the protection relay information, the process returns to the process S1 and the evaluation is repeated.

Next, in the process S7, the evaluated gas section is displayed on the monitor screen of the process unit 6. FIG. 5 shows an example of displaying the accident point on the monitor screen. Information on the gas compartment is added to the single-phase wiring diagram shown in FIG. 3, so that the correspondence with the gas compartment of the actual gas switchgear can be easily understood. The accident point is highlighted so that you can see it at a glance. Information on the accident phase is also displayed at the bottom right. In FIG. 5, No. It is illustrated that an accident has occurred in phase A of the portion corresponding to the gas compartment of 022.

FIG. 9 shows an example of another accident point determination performed by the processing unit 6. In the process of FIG. 9, the S1 process is omitted from the process of FIG. Since the current is not constantly monitored, the processing load at the time of accident point determination can be reduced.

According to the above embodiment, the accident point can be evaluated immediately after the accident occurs. This can be expected to save a lot of labor. Further, in this embodiment, since the insulating gas can be realized from inside the gas compartment without leaving the compartment, the risk of gas leakage is small, and the gas is simple and highly reliable.

1a, 1b, 1c ... Gas compartment,
2 ... Conductor,
3a, 3b, 3c ... Axial distortion sensor,
4a, 4b, 4c ... Circumferential distortion sensor,
5 ... Waveform recording unit,
6 ... Processing unit,
7 ... Ground fault,
8 ... Current sensor,
31a, 31b, 31 ... Metal pipe 32a, 32b ... Spacer

Claims (6)

In the accident point rating device of the gas insulation switchgear equipped with multiple gas compartments for accommodating conductors,
Strain detection means, which is attached to each of the metal pipes constituting the gas compartment and detects the strain of the metal pipe,
A processing means for assessing a specific gas compartment as an accident point from the gas compartments in which the strain of the strain detecting means exceeds a predetermined value is provided .
The strain detecting means detects the strain in the axial direction of the metal tube.
The processing means is an accident point rating device, characterized in that a specific gas compartment is designated as an accident point from the gas compartments in which the strain in the axial direction exceeds a predetermined value. In claim 1,
A recording device for recording the signal of the distortion detecting means is provided.
Said processing means, said recording apparatus fault point commentary constant and wherein the waveform of the stored signal is orientation and the fault point the gas compartment with the largest peak value. In claim 1,
The strain detecting means detects the strain in the circumferential direction and the strain in the axial direction of the metal tube.
The processing means, the axial direction on the basis of the distortion and the circumferential direction of the strain, the fault point commentary constant device, characterized in that orientation and the fault point a particular said gas compartment. In claim 3 ,
Said processing means, said axial find the ratio of the circumferential direction of the distortion for the distortion, the ratio fault point commentary constant device, wherein a Standardize the fault point the gas compartment becomes maximum. In claim 4 ,
A current detecting means for detecting the current flowing through the conductor, and
A breaking means for cutting off the current of the conductor and
Based on the current detected by the current detecting means, a protective means for operating the breaking means when an accident occurs is provided.
Wherein when the information from the protection means was achieved and whether the occurrence of an accident, the accident point commentary constant device said processing means, characterized in that the re-processing of the assessment of the accident point. In claim 5,
Fault point commentary constant device characterized by comprising a display means for displaying the rated gas compartment and the fault point.

Images