JPH01243327A - Abnormality monitoring device for opening/closing equipment - Google Patents

Abstract

PURPOSE:To perform highly reliable abnormality monitoring for an opening/ closing equipment by generating an abnormality detecting signal in the case of detecting two or more abnormal phenomena among heating, cracked gas, partial discharge and the like following abnormal current-carrying. CONSTITUTION:When local heating and cracked gas are detected, operation of judgement circuit 12 and 13 allows as AND-gate 20 to function. When the cracked gas and partial discharge are detected, operation of the circuit 13 and an OR-gate 19 permits an AND-gate 22 to function. When the partial discharge and the local heating are detected, operation of the gate 19 and the circuit 13 causes an AND-gate 21 to function. When all of the local heating, the cracked gas and the partial discharge are detected, operation of the circuit 12 and 13 and the gate 19 leads to function of the gates 20, 21 and 22, thereby generating an output signal. Another OR-gate disposed in a final step can generate an output signal when either one of the gates 20, 21 and 22 operates.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an abnormality detection device for switching equipment, and in particular, an abnormality detection device for switching equipment equipped with an abnormality determination logic circuit configuration suitable for improving reliability of abnormality detection. Regarding equipment.

[Conventional technology]

In order to improve the quality of power transport, it is desired that power transmission and substation equipment, including switching equipment, be made highly reliable. As a method for this purpose, there is a preventive maintenance technology that detects abnormalities that occur in equipment in advance and prevents serious accidents from occurring. If there is an abnormality in electrical conduction such as poor contact in switching equipment, phenomena such as local overheating, partial discharge, and accompanying decomposition of insulating gas will occur. Conventional techniques for detecting these phenomena include the following. For local overheating, the surface temperature of the container is measured as described in JP-A No. 56-31323, for gas decomposition as described in Utility Model Publication No. 57-363, and for detection of partial discharge as described in JP-A-59-
The method described in Publication No. 2518 and the like has been proposed. There are many other methods, including one that detects abnormalities by inserting a sensor into the container, but they are omitted here. What these methods have in common is that there is a limit to the accuracy of abnormality detection due to environmental noise at the substation site where switchgear equipment is actually installed. Furthermore, JP-A-55-41113
As described in the publication, there are devices that are equipped with multiple sensors to monitor multiple phenomena, but if a disturbance occurs in one phenomenon, a single alarm is issued, which can increase the frequency of malfunctions. There is sex. For this reason, as described in JP-A-59-10125, partial discharge, which is a phenomenon of -, is detected and judged by a combination of two sensors that detect electric pulses and ultrasonic pulses, aiming to improve accuracy. There are some, but it is still not sufficient. That is, when the same type of phenomenon occurs due to a different cause, there is a possibility that this will be regarded as an abnormality and the device will malfunction and generate an abnormal signal. For example, if the tank temperature rises abnormally due to direct sunlight in midsummer, the temperature sensor will be activated, and even if the circuit breaker is operating normally, decomposition gas will be generated due to the interruption current arc discharge, and the decomposition gas sensor will be activated. If a spark discharge occurs in the ground wire near the circuit breaker due to overvoltage, etc., the partial discharge sensor will malfunction.

In this way, if phenomena associated with power supply abnormalities are individually monitored, malfunctions may occur when similar phenomena occur due to different causes.

[Problem to be solved by the invention]

With conventional abnormality detection devices for switchgear equipment, when the preventive maintenance system activates and issues an alarm, the equipment must be disconnected from the power grid and inspected for abnormalities. In terms of reliability, there was still a problem that it could not be said to be satisfactory.

An object of the present invention is to provide an abnormality detection device for switching equipment that can detect abnormalities with higher reliability.

[Means to solve the problem]

The above objective can be achieved by configuring the system to issue an abnormality alarm when two or more phenomena such as local overheating, partial discharge, and decomposition of insulating gas due to abnormal energization are detected at the same time. 6 [Function] When a current-carrying abnormality such as a poor contact occurs for some reason in the current-carrying part of a switching device, the temperature around the part initially rises by several tens of degrees. When the current flowing through the power transmission system changes depending on the operational status of the power transmission system, the conductor repeatedly thermally expands and contracts in response, and the abnormality in the current-carrying part gradually develops over several days to several months, and the local temperature reaches several hundred degrees. SFs gas, which is generally sealed as an insulating gas in switchgear equipment, begins to decompose at 200 to 400°C, and begins to generate decomposed gases such as 5OzFz, HF, and SO2. As the abnormality progresses further, the electrode material melts due to local concentration of the current flowing at the current-carrying contact surface, and partial discharges accompanied by the generation of sparks begin to occur intermittently. As the decomposition rate of SFa gas exposed to partial discharge arc increases,
Abnormalities in the current-carrying parts develop at an accelerating rate, and in a few tens of hours to a few days, the current cannot be applied, leading to serious accidents such as ground faults. As described above, the development process of an energization abnormality takes several months, so if an abnormality can be detected during this time, it is possible to prevent a ground fault from occurring.

As mentioned above, in the process of abnormal energization of switching equipment, local overheating occurs in the early stage, local overheating and gas decomposition in the middle stage, and local overheating, gas decomposition, and partial discharge phenomena occur in parallel in the final stage. If the detection device is operating normally, it will always be possible to detect multiple phenomena until the final aspect is reached.

As a different type of failure, for example, if an electrical contact failure occurs at a fixed portion of an electric field relaxation shield installed in a high potential area, the shield becomes a floating potential and corona discharge occurs.

In this case as well, gas decomposition occurs and partial discharge and gas decomposition are detected as phenomena. If surge voltage such as lightning enters from outside in this state, it will immediately lead to a ground fault. Therefore, when local overheating and gas decomposition are detected, it is still in the middle stage of abnormal progress, but when partial discharge and gas decomposition, or local overheating is detected in addition to these, the state is close to the final stage of abnormal progress. it is conceivable that.

From this, by issuing an abnormality alarm when two or more phenomena are detected, the reliability of abnormality detection can be improved.

By configuring the system to issue different abnormality alarms depending on the combination of detected phenomena such as local overheating, gas decomposition, partial discharge, and gas decomposition, the system can be made more flexible.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an abnormality detection device for a switching device according to the present invention will be described below with reference to FIG. This figure shows an example in which the present invention is applied to a two-point circuit breaker with two disconnecting parts connected in series.
This diagram schematically shows the phase components. A conductor 3 is hermetically insulated and supported by bushings 2 and 2' in a tank 1 which is an airtight container and has a ground potential.

The breaker parts 4, 4' are electrically connected and insulatedly supported by a support (not shown). For conductor 3.

An external conductor 5.5' whose other end is connected to other power transmission/transformation equipment or a power transmission line is connected to constitute a current-carrying circuit.

In this configuration example, a temperature detection thermocouple 6.6',
A constant potential electrolytic sulfur dioxide gas detector 7, a current pulse detector 9 composed of a Hall element that detects current pulses flowing through a grounding wire 8, and an electromagnetic wave that detects airborne electromagnetic waves with an antenna 10 stretched along the tank 1. A total of 11 units are equipped.

Each of these sensors is connected to a judgment circuit 12, 13, 14, respectively.
The determination circuits 12, 13, 14, and 15 determine whether or not there is an abnormality in the input signal based on a preset detection method. The principles of abnormality detection used here will be explained individually. First, in order to detect temperature rise, in this example, a thermocouple 6°6' is installed near the upper part of the shut-off parts 4, 4' on the surface of the tank to detect an abnormality in the shut-off part. Although there are methods to directly measure the temperature of high-potential parts with insulation, we decided to use an external diagnosis method to diagnose abnormalities without compromising the reliability of the circuit breaker itself.

The number of measurement points can be increased as necessary to include other connections. Also, when installing thermocouples,
It is necessary to insulate the tank 1 to withstand the potential increase due to surges, and to cover the surrounding area with a heat insulating material to reduce the effects of sunlight, wind, and rain, but this is omitted from the diagram as it departs from the essence of the invention. There are many temperature measurement methods, including non-contact measurement that detects the amount of infrared rays emitted from the surface of the tank 1, but there is no need to limit the measurement method in particular.

The outputs of the thermocouples 6, 6' are connected to the determination circuit 12, and at the same time, the measurement results at the corresponding positions of the circuit breakers of other phases are also
It is connected to the determination circuit 12 via a measurement line 16. The determination circuit 12 is configured to output an output when the variation between different phases (here, three phases) exceeds a preset value (for example, 5K). Tank 1 temperature is
Since it is easily influenced by external conditions such as current, sunlight, wind, and rain, it is desirable to select the temperature of the same part of the other phase that is similar to these influences as the criterion. This results in
If a current abnormality occurs inside the circuit breaker, a temperature rise due to heat generated from the abnormal part can be detected. A phenomenon accompanying abnormal current flow is the decomposition of atmospheric gas due to heat and arc discharge.

When SFs gas is used as the insulating gas, SFa
, F2. Many cracked gases such as SO2, HF, and 5O2FZ are generated. Although there is a method of precisely measuring the amount of these produced using a gas chromatograph, a mass spectrometer, etc., here, the amount of S02 gas is measured using a simple constant potential electrolysis type sulfur dioxide gas detector 7. The measurement result is sent to the judgment circuit 1.
3 and it is determined whether or not there is an abnormality.However, since the amount of decomposed gas is generated even during a normal current cutoff, consideration must be given to this point. FIG. 2 shows the time characteristics of the decomposed gas amount S, and shows the decomposed gas amount 17 in a normal state and the decomposed gas amount 18 in an abnormal state when the current is cut off at time t1. Under normal conditions, the decomposed gas rapidly increases by several ppm to several tens of ppm at time t1, and then due to the effect of the adsorbent installed in the circuit breaker, it takes a time constant of several hours to several tens of ppm until it reaches equilibrium with the adsorption characteristics of the adsorbent. Shows a ten-hour decrease characteristic.

If there is an abnormality 18, the current increases at a certain slope and then the current is cut off at time tl, resulting in a characteristic in which the amount of occurrence at that time is superimposed. Therefore, in determining abnormalities in decomposed gases, it is sufficient to configure the structure to output an output when the time change exceeds a reference value, rather than the value itself of the amount of decomposed gas, and the reference value is determined by the detection sensitivity of the detector. (here 0.
3ppm 7 days).

There are methods to detect partial discharge due to abnormality in energization, such as by measuring vibrations, electromagnetic waves, pulse current, etc. In this example, the latter two are installed, and when one of them detects an abnormality.

The system assumes that a partial discharge or abnormality has occurred.

That is, when abnormal electromagnetic wave radiation is detected by the antenna 10 and the electromagnetic wave meter 11, the determination circuit 14 compares it with a reference value and outputs an output signal when it exceeds the reference value. Similarly, when the current pulse detector 9 detects an abnormal pulse, the determination circuit 15 processes it according to a preset determination algorithm, and outputs an abnormal signal when the standard is not met.

In either measurement method, the detection sensitivity is about a discharge of several tens of picocoulombs per second, but at the substation site there is back noise equivalent to a discharge of the maximum picocoulomb per second.
Removal of back noise is important in partial discharge detection.

In this configuration, when either one of the determination circuits 14 and 15 outputs an abnormal signal, the OR gate 19 opens and the AND
An abnormality signal is output to the gate 24. In this configuration, in order to detect partial discharge, the electromagnetic wave sensor only needs to detect an abnormality in one of the electromagnetic pulse sensors, so the abnormality judgment standard can be set high (in this example, 2000 picochons/second). In the configuration described above, when heat generation due to an abnormality in energization is detected, the determination circuit 12 outputs an abnormality signal to prevent an increase in decomposed gas. When it is recognized, judgment circuit 1
3 outputs. Further, if a partial discharge occurs, the determination circuit 14
．． 15 outputs an abnormal signal, and the OR gate 19 operates. These signals are individually monitored on a monitor panel display, etc., and an AN configured to operate when any two or more of the respective outputs is detected.
A 1 energization abnormality detection signal 24 is output from the D gates 20, 21° 22 and the OR gate 23. That is, when local overheating and decomposition gas are detected, the judgment circuits 12 and 13 operate, so the AND gate 20 is 1. When decomposition gas and partial discharge are detected, the judgment circuit 13 and OR gate 19 operate. Therefore, AND gate 22 operates, and when partial discharge and local overheating are detected, OR gate 19 and judgment circuit 13 operate, so AND gate 21 operates, and when local overheating, decomposition gas, and partial discharge are all detected, Judgment circuit 12
．． 13 and OR gate 19 operate, all AN
D gates 20, 21, and 22 operate to generate output signals. Further, since the OR gate provided at the final stage is configured to output an output signal when any one of the AND gates 20, 21, and 22 operates, the above-described operation is realized. With the above configuration, it is possible to realize a highly reliable preventive maintenance system that does not malfunction even in the presence of noise.

In the one shown in FIG. 3 showing a different embodiment of the present invention, the AND gate that outputs an abnormal signal only when all three types of phenomena, temperature rise and gas decomposition 1 partial discharge, is detected is connected to the judgment circuit 12,
13, connected to the output of OR gate 19. Thereby, it is possible to further improve the reliability of the abnormality detection signal output from the AND gate 24.

Various other ways of assembling the logic circuit can be considered, but the gist of the present invention is that when different phenomena such as heat generation, gas decomposition, partial discharge, etc. accompanying abnormal energization are detected at the same time, it is regarded as an abnormality and an abnormality detection signal is generated. This is what I did.

Another embodiment of the present invention, shown in FIG. 4, is equipped with a temperature sensor 6,6' for detecting temperature rise and a decomposition gas sensor 7 for detecting decomposition of gas, and two types of sensors can detect two different phenomena. It is designed to detect. The outputs of the judgment circuits 12 and 13 connected to each are sent to the AND gate 20.
In this example, the configuration is such that the abnormality detection signal 24 is output only when both of them determine that it is abnormal. This makes it possible to improve the reliability of the detection circuit against failures.

Further, in the embodiment shown in FIG. 5, two types of sensors are used to detect two phenomena, but in this example, a temperature rise is detected by a temperature sensor, and a partial discharge is detected by an ultrasonic microphone 25. The output of the ultrasonic microphone 25 is amplified by an amplifier 26 and input to a determination circuit 27 . At the substation site, in order to reduce electrically induced noise, it is effective to connect the amplifier 26 and the determination circuit 27 with an optical cable 28 via an electrical-optical or optical-electrical conversion circuit. The AND gate 20 is configured to output an abnormality detection signal 24 when two phenomena, temperature rise and partial discharge, are recognized. In the development process of an abnormality, a temperature rise occurs due to heat generation at the beginning, followed by partial discharge and gas decomposition, so from the perspective of early detection of an abnormality, it is necessary to detect at least the temperature rise of the two phenomena. It's good.

The embodiment of the present invention shown in FIG. 6 is aimed at the connecting portion 31 of the busbars 30, 31' of the gas-insulated switchgear 29, and includes a temperature sensor 6, an acceleration sensor 38 for detecting tank vibration, and a preamplifier 39. It was established. It is preferable to install the sensor near the connection where abnormalities in power supply occur frequently.

It is possible to reduce the number of sensors within the range permitted by detection sensitivity. However, it is preferable to arrange at least one set of sensors in one gas compartment separated by insulating spacers 32, 32'. The output of the preamplifier 39 is input to the judgment circuit 40, and the reference value, for example, 0.005G (G is gravitational acceleration)
It is judged as abnormal when it exceeds.

Furthermore, the 7th rJi! In the embodiment shown in FIG. 1, the determination circuit of the embodiment shown in FIG. A first abnormality alarm signal 36 is outputted through 34.

At the same time, the output through the OR gate 33 and the output through the OR gate 19 of the partial discharge determination circuit 14.15 are output through an AND gate 35 to output a second abnormality alarm signal 37. The first abnormality alarm signal 36 indicates the middle stage of abnormality development, and when this signal is issued, there is a grace period such as conducting a detailed inspection of the equipment. The second abnormality alarm signal 37 indicates the final state, and measures such as stopping the equipment are immediately taken.

In this way, by changing the response depending on the type of alarm, the system has the feature of increasing its flexibility.

Table 1 shows combinations suitable for detecting energization abnormalities by applying the present invention. Here, the tank vibration detection method was considered separately from the partial discharge detection method because the detection means are quite different from those for measuring other electrical signals. In the table, O marks are effective combinations, 0 marks are combinations that can be expected to be effective, and x marks are combinations that are not expected to be effective as a method for detecting energization abnormalities.

Table 1 [Effects of the invention] If the abnormality monitoring device for switching equipment is configured as in the present invention,
When different phenomena such as heat generation, gas decomposition, partial discharge, etc. associated with a power supply abnormality are detected at the same time, it is considered that an abnormality has occurred, and an abnormality detection signal is issued.Even if the same type of phenomenon occurs due to different causes, it will not be caused by malfunction. A highly reliable abnormality monitoring device can be configured without outputting an abnormality detection signal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the abnormality monitoring device for switching equipment of the present invention, FIG. 2 is a characteristic diagram showing some operating characteristics of FIG. 1, and FIGS. 3 to 7 FIG. 2 is a block diagram showing a different embodiment of the abnormality monitoring device for switching equipment according to the present invention. DESCRIPTION OF SYMBOLS 1... Tank, 3... Conductor, 4, 4'... Breaking part, 31... Connection contact, 6.6', 7, 9, 10,
11...Detector, 12, 13, 14, 15... Judgment circuit.

Claims (1)

[Scope of Claims] 1. It has an airtight container that encloses an insulating gas, and a conductor that is insulated and supported in the airtight container and is configured to be able to conduct current, a current-carrying part that includes a interrupting part, a connecting contact, etc., A detector that detects a plurality of phenomena associated with an abnormality occurring in the current-carrying part, and a determination circuit that determines the presence or absence of an abnormality from the output of the detector, wherein the output of the determination circuit is An abnormality monitoring device for switching equipment, characterized in that it is configured to output an abnormality detection signal when an abnormality in a phenomenon is detected. 2. The determination circuit is configured to output an abnormality detection signal when the output of the determination circuit detects at least two of the three phenomena of temperature rise, gas decomposition, and partial discharge caused by abnormality occurrence. An abnormality monitoring device for switching equipment according to claim 1. 3. A claim characterized in that the determination circuit is configured to issue different abnormality detection signals when detecting temperature rise and gas decomposition and when detecting temperature rise and/or gas decomposition and partial discharge. An abnormality monitoring device for switching equipment according to item 2. 4. In a gas insulated device having an airtight container that encloses an insulating gas and a conductor that is insulated and supported in the airtight container and configured to be able to conduct current, a temperature detection means of the airtight container, a structural member of the airtight container, It has a means for detecting a minute current flowing between the ground, a means for detecting a decomposed gas of an insulating gas in the airtight container, a means for detecting a sound wave or an ultrasonic wave in the airtight container, and a temperature detection means. and an ultrasonic detection means, or a means for notifying that there is an abnormality in energization when the temperature detection means and the decomposed gas detection means output a detection signal, and the microcurrent detection means and the sonic or ultrasonic detection means, or the An abnormality monitoring device for switching equipment characterized by comprising means for notifying a dielectric strength abnormality when a minute current detection means and a decomposition gas detection means output a detection signal.