JP2000139009A - Pressure monitoring device for electrical insulating gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of an electrical insulating gas from many already existing GISs(gas insulated switchgears) to the atmosphere as much as possible by detecting gas pressure drops with accuracy in early stages and issuing gas pressure inspection requesting signals. SOLUTION: The connecting pipe section 11 of a pressure relay 1 is connected to the pressure introducing pipe 3 of the pressure vessel 2C of a GIL(gas insulated transmission line). The high-pressure alarming pressure of the relay 1 is set on the higher-pressure side than the initial charging pressure of an SF6(sulfur hexafluoride) gas and, when a temperature- compensated pressure becomes higher than the alarming pressure, the relay 1 outputs a high- pressure alarm. Then the gas leakage alarming pressure of the relay 1 is set on the lower- pressure side than the initial charging pressure and, in addition, the gas pressure inspecting pressure of the relay 1 is set between the initial charging pressure and the gas leakage alarming pressure. When the temperature-compensated pressure becomes lower than the gas pressure inspecting pressure, the relay 1 outputs a gas pressure inspection requesting signal and, when the pressure becomes lower than the gas leakage alarming pressure, a gas leakage alarming signal. The temperature-compensated pressure is calculated from the pressure and temperature detected by means of a composite pressure and temperature sensor and the average value of the pressures measured within a prescribed period of time before dawn and the moving average value in a plurality of days are used as the temperature-compensated temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas-insulated switchgear (hereinafter referred to as GIS: Gas Insulate) in the electric power field, for example.
d Switchgear. ), Gas insulated transmission line (hereinafter, GI
L: It is called Gas Insulated transmission Line. ) And gas insulated transformers (Gas insulated transformer) related to the technology to monitor the gas for electrical insulation sealed in a pressure vessel, such as a small gas pressure due to leakage of this electrical insulation gas into the atmosphere The present invention relates to a pressure monitoring device for an electrical insulating gas that detects a drop at an early stage. In the following description, the electrical equipment in which the above-mentioned electric insulating gas is sealed is generically referred to as GIS, and gas and gas have the same meaning.

[0002]

2. Description of the Related Art Hitherto, as a gas state monitoring technique in GIS, there have been proposed, for example, Japanese Patent Application Laid-Open Nos. 7-24109 and 6-67113.
In the technology disclosed in Japanese Patent Application Laid-Open No. Hei 7-24109, a gas pressure sensor is provided in each of a plurality of pressure vessels (ground metal vessels), and the gas pressure and the gas temperature in the corresponding pressure vessel are detected by each gas pressure sensor. Then, a gas pressure signal and a gas temperature signal are transmitted from each gas pressure sensor to the monitoring means. The monitoring means converts the gas pressure into a gas pressure at a predetermined temperature based on the gas pressure signal and the gas temperature signal, and compares the converted gas pressure with a determination reference value to determine the occurrence of a gas leak or the like in each pressure vessel. It is.

[0003] In the technique disclosed in Japanese Patent Publication No. 6-67113, an analog output proportional to the gas pressure from a gas pressure sensor provided in a pressure vessel having a plurality of compartments, and a GIS are used.
An analog output proportional to the outside air temperature from a temperature sensor disposed outside the unit detects a gas pressure for monitoring gas leakage converted to a reference temperature. Then, the gas pressure for monitoring the gas leak is periodically accumulated and held, and the gas leak is monitored from the change tendency of the accumulated and held gas pressure.

On the other hand, in December 1997, the "International Framework Convention on Climate Change Third Conference (COP3)", the so-called "Kyoto Conference on Global Warming Prevention" was held, and carbon dioxide, methane gas, and gas for electrical insulation were held. Greenhouse gases such as sulfur hexafluoride (SF ₆ ), which is widely used as a target, are subject to regulation, and numerical targets for reduction have been approved. Considering the current situation where sulfur hexafluoride gas is used in large quantities (on a global scale), regardless of whether it is a new GIS or an existing GIS,
It is urgently necessary to consider how to reduce the leakage of sulfur hexafluoride gas into the atmosphere.

[0005] Further, gas leakage in GIS is far more spontaneous than emergency leakage due to a sudden accident, and measures against such a natural leak are effective measures against gas leakage. However, when a gas leak alarm is issued in response to an emergency leak, it can be detected by a sudden change in gas pressure or the like. There is a need to.

As an interim measure to reduce the leakage of sulfur hexafluoride gas to the atmosphere, it has been studied to control the total amount by mixing a gas having electrical insulation such as nitrogen gas or argon gas. , SF as a permanent measure
R & D is underway to discover the invention of " ₆ alternative gases". However, even with such a gas, it is useful to detect a small decrease in gas pressure at an early stage in consideration of the maintenance work by a gas leak alarm.

[0007]

Here, in the present situation where GIS is widely spread and installed around the world, to prevent gas from leaking into the atmosphere is naturally overwhelming as a countermeasure with the newly established GIS. This is nothing less than taking measures for the existing GIS, which has a large volume. However, Japanese Patent Application Laid-Open No. 7-241
It is extremely difficult to add a monitoring system as disclosed in Japanese Patent Application Publication No. 009 or Japanese Patent Publication No. 6-67113 to an existing GIS in terms of installation space or cost.

By the way, GIS is newly established or existing,
Regardless of the presence or absence of the “monitoring system”, at least one of a pressure gauge, a compound gauge, a pressure switch, and a density switch (temperature compensation pressure switch) is connected to the pressure vessel (one gas compartment) through a pressure introduction pipe. One is attached.

In view of this, the present invention focuses on this point and attaches a pressure monitoring device to the pressure introducing pipe, thereby issuing a gas pressure check request signal at an early stage in many existing GISs to an inspector so as to inspect the observer. And to prevent gas leakage into the atmosphere as much as possible. It is another object of the present invention to accurately detect a slight decrease in gas pressure at such an early stage.

[0010]

According to a first aspect of the present invention, there is provided a pressure monitoring apparatus for an electrically insulating gas, comprising: a connecting pipe portion connectable to a pressure introducing pipe of a pressure vessel in which the electrically insulating gas is sealed; Gas pressure detecting means for detecting the gas pressure of the electric insulating gas in the pressure vessel through the connection pipe portion, and the electric insulation higher than a gas leak alarm pressure corresponding to a low pressure side control limit of the electric insulating gas. A first control for setting a gas pressure check pressure on the low pressure side near the initial filling pressure of the working gas and outputting a gas pressure check request signal when the gas pressure detected by the gas pressure detecting means reaches the gas pressure check pressure. Means, and a second control means for outputting a gas leak alarm signal when the gas leak alarm pressure is set and the gas pressure detected by the gas pressure detecting means becomes lower than the gas leak alarm pressure. Characterized by .

According to the pressure monitoring apparatus for an electrically insulating gas according to the first aspect of the present invention, the pressure introduction of the pressure vessel to which the density switch or the like of the GIS is installed irrespective of whether it is new or existing. The connection pipe can be connected to the pipe, and the pressure of the electric insulating gas can be detected through the connection pipe by the gas pressure detection means. In the first control means, a gas pressure check pressure on a low pressure side higher than the gas leak alarm pressure and near an initial filling pressure of the electric insulating gas is set. The first control means outputs a gas pressure check request signal when the gas pressure detected by the gas pressure detecting means reaches a gas pressure check pressure. Can be encouraged,
Gas leakage to the atmosphere can be prevented as much as possible. Also,
In the second control means, a gas leak alarm pressure corresponding to a low pressure side control limit of the electric insulating gas is set. The second control means outputs a gas leak alarm signal when the gas pressure detected by the gas pressure detecting means reaches a gas leak alarm pressure, so that functions such as a density switch can be maintained.

According to a second aspect of the present invention, there is provided an electric insulating gas pressure monitoring apparatus having the configuration of the first aspect, further comprising an output terminal for outputting the gas pressure check request signal and the gas leak alarm signal. The gas pressure detecting means, the first control means, and the second control means are housed in one case, and the output terminal is provided in the case.

According to the pressure monitoring apparatus for an electrically insulating gas according to the second aspect of the present invention, in addition to the function and effect of the first aspect, the gas pressure detecting means and the first and second control means are arranged in one. The case is provided with an output terminal for receiving a gas pressure check request signal and a gas leak warning signal.
In the IS, the pressure monitoring device can be easily provided instead of the existing density switch or the like.

According to a third aspect of the present invention, there is provided a pressure monitoring apparatus for an electrically insulating gas having the structure of the first or second aspect, wherein the gas pressure detecting means detects the pressure of the electrically insulating gas. And a temperature sensor for detecting the temperature of the electric insulating gas, and the gas pressure detected by the gas pressure detecting means is a pressure detected by the pressure sensor and detected by the temperature sensor. It is a temperature compensation pressure converted into a standard temperature pressure based on the temperature.

According to the third aspect of the present invention, in addition to the function and effect of the first or second aspect, the gas pressure detecting means is based on the temperature compensation pressure. Therefore, the influence of the temperature difference can be reduced and a minute gas pressure drop can be accurately detected.

According to a fourth aspect of the present invention, there is provided an apparatus for monitoring the pressure of an electrically insulating gas, comprising the configuration of the third aspect, wherein the pressure sensor and the temperature sensor are combined sensors having the same structure. I do.

According to the pressure monitoring apparatus for an electrically insulating gas according to the fourth aspect of the present invention, in addition to the functions and effects of the third aspect, the pressure sensor and the temperature sensor are combined sensors having the same structure. Therefore, the pressure monitoring device can be easily assembled at the time of manufacture, and can be easily installed on a GIS or the like.

According to a fifth aspect of the present invention, there is provided a pressure monitoring apparatus for an electrically insulating gas having the configuration according to the third or fourth aspect, wherein the pressure sensor and the temperature sensor detect a change in pressure on the same diaphragm. It is characterized by a pressure sensor using a piezoresistive element in a distorted part and a temperature sensor using a piezoresistive element in a part that is not distorted by pressure change.

According to the pressure monitoring apparatus for an electrically insulating gas according to the fifth aspect of the present invention, the temperature sensor is adjacent to the pressure sensor in addition to the effects of the third or fourth aspect. Therefore, the accuracy of detecting the temperature of the electric insulating gas whose pressure is detected by the pressure sensor is improved.

According to a sixth aspect of the present invention, there is provided an apparatus for monitoring the pressure of an electrically insulating gas, comprising the configuration of the first, second, or third aspect, wherein the gas pressure detected by the gas pressure detecting means is equal to the pressure of the gas. The first control means, which outputs a gas pressure check request signal when the gas pressure check pressure is reached, sets the gas pressure detected by the gas pressure detection means to a lower pressure side than near the initial filling pressure of the electric insulating gas. When the gas pressure becomes lower than the set first predetermined set value, a first gas pressure check request signal is output, and the gas pressure detected by the gas pressure detecting means is set to the gas leak alarm pressure and the electric insulation gas. A second gas pressure check request signal is output when the gas pressure becomes lower than a second predetermined set value set in the vicinity of the average value with the initial filling pressure.

According to the pressure monitoring apparatus for an electrically insulating gas according to the sixth aspect of the present invention, in addition to the effects of the first, second, or third aspect, the degree of reduction of the gas pressure is also reduced. Can be determined in two stages.

According to a seventh aspect of the present invention, there is provided an electric insulating gas pressure monitoring apparatus having the structure of the sixth aspect, wherein the first gas pressure check request signal and the second gas pressure check request signal are different from each other. , And performs a logical sum operation and outputs the signal as a gas pressure check request signal.

According to the pressure monitoring apparatus for an electrically insulating gas according to the seventh aspect of the present invention, in addition to the function and effect of the sixth aspect, the first and second gas pressure check request signals are set to one.
Since the signals can be of different types, they can be output from one output terminal, and the number of wirings can be reduced.

According to an eighth aspect of the present invention, there is provided a pressure monitoring apparatus for an electrically insulating gas having the structure of the first or second aspect, wherein the gas pressure check request signal and the gas leak alarm signal are connected in parallel. Is output.

According to the pressure monitoring apparatus for an electrically insulating gas according to the eighth aspect of the present invention, in addition to the effects of the first or second aspect, a gas pressure check request signal and the gas leak alarm are provided. An output terminal can be shared for outputting a signal, and the number of wirings is reduced, so that installation in an existing GIS can be particularly easily performed.

According to a ninth aspect of the present invention, there is provided an electric insulating gas pressure monitoring apparatus having the configuration of the first, second, third or sixth aspect, wherein the gas pressure check request signal is a switch output. And a flashing signal that alternately switches between open and closed or on and off.

According to the pressure monitoring apparatus for an electrically insulating gas according to the ninth aspect of the present invention, in addition to the effects of the first, second, third or sixth aspect, the gas pressure Inspection request signals can be easily identified.

According to a tenth aspect of the present invention, there is provided an electric insulating gas pressure monitoring apparatus having the configuration of the ninth aspect, wherein the gas pressure check request signal corresponds to the degree of gas pressure decrease to a blinking duty ratio. It is a blinking signal.

According to the pressure monitoring apparatus for an electrically insulating gas according to the present invention, the degree of the gas pressure drop is determined by the blinking duty ratio, that is, the blinking mode. You can check.

An eleventh aspect of the present invention provides the pressure monitoring apparatus for an electrically insulating gas according to the tenth aspect of the present invention, wherein the degree of the gas pressure drop depends on the initial sealing pressure of the electrically insulating gas and the electrical insulation. It is characterized by a degree obtained by a difference between an initial filling pressure and a gas pressure detected by a gas pressure detecting means with respect to a difference between a gas leak alarm pressure corresponding to a low pressure side management limit of service gas.

According to the pressure monitoring apparatus for an electrically insulating gas according to the eleventh aspect of the present invention, in addition to the functions and effects of the tenth aspect, the pressure within the pressure range between the initial sealing pressure and the gas leak alarm pressure is provided. The degree of decrease in gas pressure can be confirmed.

[0032] According to a twelfth aspect of the present invention, a pressure monitoring device for an electric insulating gas detects a pressure of the electric insulating gas sealed in a pressure vessel, and detects a temperature of the electric insulating gas. A temperature sensor, pressure detecting means for obtaining a temperature compensation pressure obtained by converting a pressure detected by the pressure sensor into a standard temperature based on a temperature detected by the temperature sensor, and a low pressure side management of the gas for electrical insulation. A gas pressure check pressure based on a first predetermined set value is set higher than a gas leak alarm pressure corresponding to the limit and lower than near an initial filling pressure of the electric insulating gas, and the temperature compensation pressure is set to the first pressure.
Control means for outputting a first gas pressure check request signal when the gas pressure becomes lower than the gas pressure check pressure based on a predetermined set value,
The control means uses an average value of the temperature compensation pressures at predetermined times on a plurality of days as the temperature compensation pressure to be compared with the gas pressure check pressure based on the first predetermined set value.

According to the pressure monitoring apparatus for an electrically insulating gas according to the twelfth aspect of the present invention, even if the measured temperatures are different in a plurality of measurements, they are converted into a temperature compensation pressure, so that there is no problem for the time being. Since the temperature is substantially constant at a constant time even on different days, the accuracy of the temperature compensation pressure is increased, and a minute decrease in gas pressure can be accurately detected by the stable temperature compensation pressure. Further, since the average of a plurality of days is obtained, even if there is a day with an abnormal climate, the difference between the days can be reduced.

According to a thirteenth aspect of the present invention, there is provided a pressure monitoring apparatus for an electrically insulating gas, comprising the configuration of the twelfth aspect, wherein the average value of the temperature compensation pressure is a value obtained by moving average over a predetermined number of days. And

According to the pressure monitoring apparatus for an electrically insulating gas according to the thirteenth aspect of the present invention, in addition to the effects of the twelfth aspect, for example, a gradual change over a long period of time, such as a change in the average temperature in each season. It is possible to accurately detect a small decrease in gas pressure while following a temperature change.

According to a fourteenth aspect of the present invention, there is provided a pressure monitoring apparatus for an electrically insulating gas, comprising the configuration of the twelfth or thirteenth aspect, wherein the temperature compensation pressure at the predetermined time is set for a predetermined time near dawn. And the average value of the plurality of temperature compensation pressures detected.

According to the pressure monitoring apparatus for an electrically insulating gas according to claim 14 configured as described above, in addition to the functions and effects of claim 12 or claim 13, the temperature of the outside air is substantially equilibrium before dawn. Therefore, the temperature compensation pressure as an average value becomes a stable value, and a minute gas pressure drop can be detected accurately.

According to a fifteenth aspect of the present invention, a pressure monitoring apparatus for an electrically insulating gas has the configuration according to the twelfth, thirteenth, or fourteenth aspect, wherein the pressure sensor and the temperature sensor are of the same structure. The composite sensor is characterized by a pressure sensor using a piezoresistive element in a portion distorted by pressure change on the same diaphragm and a temperature sensor using a piezoresistive element in a portion not distorted by pressure change.

According to the pressure monitoring apparatus for an electrically insulating gas according to the fifteenth aspect, the pressure sensor and the temperature sensor have the same effects as those of the twelfth, thirteenth, and fourteenth aspects. Since the pressure sensor is a composite sensor having the same structure, the pressure monitor can be easily assembled at the time of manufacture, and can be easily installed on a GIS or the like.
Since the temperature sensor is adjacent to the pressure sensor, the accuracy of detecting the temperature of the electric insulating gas whose pressure is detected by the pressure sensor is increased, and the accuracy of the calculated temperature compensation pressure is also increased.

[0040]

Preferred embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a pressure relay (pressure switch) 1 and a GIL (gas insulated transmission line) 2 as a pressure monitoring device of the embodiment. In the GIL 2, a transmission line 2B through which a current flows at a voltage of about 30,000 to 500,000 [V] is provided, and the transmission line 2B is supported by an insulating spacer 2A also serving as a sealing. Spaces separated by the insulating spacer 2A and the GIL 2 form independent pressure vessels 2C, and SF ₆ gas is sealed in each pressure vessel 2C as an electric insulating gas.

The pressure relay 1 is provided for each pressure vessel 2C, and the pressure relay 1 and the pressure vessel 2C are connected to the pressure introducing pipe 3C.
It is communicated with. Each of the pressure relays 1 detects the pressure and temperature of the SF ₆ gas in the corresponding pressure vessel 2C via the pressure introducing pipe 3, and detects a high-pressure alarm or a gas pressure check according to the gas pressure state of the SF ₆ gas. The state of occurrence of a request or the like is displayed, and a signal corresponding to each state is output to the electric device circuit operation unit 10 via the output signal line 4. In addition, the electric device circuit operation unit 10 responds to various signals from the pressure relay 1 by GI
It outputs various operation signals for operating L2.

FIG. 2 is a view showing a state in which the pressure relay 1 is mounted. A gauge box 20 is attached to the GIL 2, and the pressure introducing pipe 3 and the pressure relay 1
Is stored. The pressure introducing pipe 3 includes a normally open stop valve 3A, a normally closed stop valve 3B, and a T-shaped pipe 3C. The pressure relay 1 is fixed to the gauge box 20 by a mounting plate 1B, and a connection pipe portion 11 at a lower end of the pressure relay 1 is connected to a pressure vessel 2C via a T-tube 3C and a stop valve 3A. Nine output signal lines 4 connected to a 12-pole terminal block of the pressure relay 1 described later.
A predetermined wiring is applied to the electric device circuit operation unit 10 via the conduit opening 20A of the gauge box 20.

The gauge box 20 is provided with a conventional pressure gauge, a compound gauge, a pressure switch, a density switch and the like in the existing GIS, for example. The pressure relay 1 can be easily attached to the tube 3 and the gauge box 20.

Here, various types of alarms and
Explanation of various set values used as judgment criteria for these alarms
I do. The gas pressure to be determined in this embodiment
Is the SF detected by the pressure sensor₆Actual detection pressure of gas
Force (actual pressure) and this actual pressure is SF ₆Based on the detected gas temperature
And the temperature converted to the pressure at a predetermined temperature (20 ° C)
Compensation pressure (correction pressure)
Is mainly used.

FIG. 3 is a diagram showing an example of the set value in the embodiment, and the vertical axis shows the pressure (MPa: megapascal). First, the initial filling pressure PG of SF ₆ gas is set to 0.1.
The first high pressure alarm pressure PH1 is set to 0.70 (MPa) and the second high pressure alarm pressure PH2 is set to 0.90 (MPa) on the higher pressure side, and the temperature compensation pressure is set to the first high pressure alarm pressure PH1. When the above is reached, a first high-pressure alarm is output, and when the actual pressure exceeds the second high-pressure alarm pressure PH2, a second high-pressure alarm is output. The outputs of the first high-pressure alarm and the second high-pressure alarm are ORed together with an SP (impact pressure) detection signal at the time of occurrence of impact pressure detected by the pressure rise rate and an abnormality detection signal by self-diagnosis. Is output as a one-stage alarm. As a result, an alarm of one stage on the high voltage side is output from a pair of output terminals.

On the lower pressure side than the initial filling pressure P G, the operation locking pressure PL 2 is 0.40 (MPa), and the gas leak alarm pressure P L is between 0 and 0 between this operation locking pressure P L2 and the initial filling pressure P G. 45 (MPa). Further, between the initial filling pressure PG and the gas leak alarm pressure PL1, the gas pressure check pressure PM1 which is the first predetermined set value is 0.49 (MPa), and the gas pressure check pressure PM2 which is the second predetermined set value. Is set as 0.475 (MPa). When the temperature compensation pressure falls below the gas pressure check pressure PM1, a first gas pressure check request signal is output, and when the temperature compensation pressure falls below the gas pressure check pressure PM2, a second gas pressure check request signal is output. When the temperature compensation pressure becomes equal to or lower than the gas leak alarm pressure PL1, a gas leak alarm signal is output, and when the temperature compensation pressure becomes equal to or lower than the operation lock pressure PL2, an operation lock signal is output. The first and second gas pressure check request signals based on the two types of gas pressure check pressures PM1 and PM2 are ORed,
The logical OR of these two types is defined as one stage, and one stage of the gas leak alarm signal and one stage of the operation lock signal, and a total of three stages of low pressure side signals are three stages.
Output from a pair of output terminals.

The first high pressure alarm pressure PH1, the gas leak alarm pressure PL1, and the operation locking pressure PL2 are values set by a trimmer described later, and the second high pressure alarm pressure PH2, the gas pressure check pressures PM1, PM2, and Set value for SP detection is ROM
Is stored in advance or adjusted by adjusting the value.
This is the value stored in the EPROM. Further, the second high pressure alarm pressure PH2 is set corresponding to the actual pressure, and the other is set corresponding to the temperature compensation pressure. It goes without saying that it is optional to set by a trimmer or to store it in the ROM in advance. For example, the operation is the same even if all are performed by a trimmer or all are stored in the ROM.

FIG. 4 is an external front view of the pressure relay 1, and FIG.
5A is a bottom view of the external appearance of the pressure relay 1 (a view taken along the line AA in FIG. 4), and FIG. 5B is a side view of the external appearance (a view taken along the line BB in FIG. 4). The pressure relay 1 has a rectangular front case 12 and a rectangular back case 13.
The left end surface of the front case 12 and the rear case 13 is partially cut out so that the output signal line 4 connected to the terminal 14 can be drawn out. In addition, a terminal cover 12a is provided on a part of the left side of the front case 12 so as to cover the terminal 14. The terminal cover 12a can be freely opened and closed as shown by a dashed line in FIG. The front end of the terminal 14 is locked with the end surface of the front case 12 so that the front surface of the terminal 14 can be fixed with the lid closed.

An operation display panel 1P provided on the front of the front case 12 has a numerical display 1D for displaying a detected pressure and a detected temperature, two LEDs 15a and 15b indicating the display contents of the numerical display 1D, , A display changeover switch 16 for changing the display content of the numerical value display section 1D is provided. Normally, the temperature compensation pressure (MPa (at 20 ° C.)) is displayed on the numerical value display section 1D. In this state, every time the display changeover switch 16 is pressed once, the detected pressure (actual pressure: MPa) → The temperature is displayed in the order of the detected temperature (° C.), and the display returns to the temperature compensation pressure again. At this time, the LED 15a is turned on when the detected pressure (actual pressure) is displayed, and the LED 15b is turned on when the detected temperature is displayed.

It should be noted that only the display changeover switch 16 is provided as an operation unit of the operation display panel 1P.
To set various setting values, switches and the like inside the front case 12 are operated. Further, since the front case 12 is fastened and fixed to the back case 13 by screws (not shown) accommodated in the terminal cover 12a, in a normal state, the screws (not shown) are intentionally removed and the front case 12 is not opened. As long as the monitor is the display switch 1
6 can be operated only, and various setting values cannot be changed. Thus, there is no fear that an operation error occurs, and the configuration is easy to use.

The operation display panel 1P is used for displaying a high-pressure alarm which is lit (or flashes quickly for 0.25 seconds / off for 0.25 seconds (hereinafter referred to as "fast flash")) at the time of a high-voltage alarm. LED 15c, a LED 15d for displaying a gas pressure check request which is lit red (duty blinking) when a gas pressure check is requested, an LED 15e for displaying a gas leak warning which is lit red (or flashes quickly) when a gas leak warning is made, an operation chain An LED 15f for operating lock display, which is lit red (or flashes rapidly) when the lock is output, and an LED 15g for displaying an error, which is lit red (or flashes quickly) when an abnormality is detected by self-diagnosis, are provided.

A pressure temperature detecting section 17 is provided on the lower surface of the back case 13, and a connection pipe section 11 connectable to the pressure introducing pipe 3 is mounted below the pressure temperature detecting section 17. .

FIG. 6 is a cross-sectional view of the pressure / temperature detector 17. The pressure / temperature detector 17 includes a cap 17a to which the connection pipe 11 is attached, a header 17b, and the cap 17a and the header 17b. The cover 17c is disposed in the formed gap, transmits the pressure of the SF ₆ gas from the connection pipe 11, and protects the metal diaphragm 17d. The cover 17c is deformed according to the pressure transmitted from the cover 17c. And a relay board 17f to which the output terminal of the sensor chip 17e is connected. A flat cable 171 for extracting an output signal corresponding to the detected pressure and the detected temperature is connected to the relay board 17f.

FIG. 7 is a plan view of the sensor chip 17e. The sensor chip 17e includes an electrode 21, a conductive layer 22, and piezoresistive elements 23, 2 on the surface of a silicon chip.
4, the pressure sensor and the temperature sensor are formed on one chip. The inside of the dashed line shown in the figure is a part that performs the function of a diaphragm that can be elastically deformed (slightly deformed) by pressure, and a piezoresistive element 23 that constitutes a pressure sensor is formed in this diaphragm part. The outside of the broken line is a fixed portion fixed to the header portion 17b, and the electrode 21 and the piezoresistive element 24 constituting the temperature sensor are formed on this fixed portion.

Each electrode 21 and the piezoresistive element 23 are connected by a conductive layer 22 as shown in FIG.
Electrodes 21 are formed at both ends of each of FIGS.
The circuit shown in FIG. Note that in FIG.
The electrode 21 indicated by and the terminal indicated by in FIG. 8 correspond to each other. Then, as shown in FIG. 8A, an input voltage is applied to the terminals of
The pressure sensor 25 is formed by extracting the original pressure detection signal SP0 from the terminal. Further, the temperature sensor 26 is formed by extracting the raw temperature detection signal ST0 from the terminals of. The electrode 21 is connected to the ground. As a result, the pressure sensor 25 is constituted by a portion of the piezoresistive element which is distorted by a change in pressure, and the temperature sensor 26 is constituted by a portion of the piezoresistive element which is not distorted by a change in pressure. The sensor chip 17e forms a composite sensor in which a pressure sensor and a temperature sensor are integrally formed on a silicon chip.

FIG. 9 is a front view showing a state where the front case 12 of the pressure relay 1 is removed, and a circuit board 31 on which a microcomputer and an analog circuit (not shown) are mounted.
Are arranged. On the circuit board 31, a 3-digit 7-segment display 32a constituting the numerical value display section 1D, a rectangular LED 32b for displaying a minus sign, the LEDs 15a to 15g for various displays, and a display changeover switch 16 are provided. In addition, a return switch 33 for manually resetting the operation lock state, a setting changeover switch 34 for performing the setting operation of the various set values, a trimmer 35 for setting the first high pressure alarm pressure, a gas leak alarm pressure And trimmer 3 for setting operation lock pressure
7 are provided. A short-circuit pin 45a for switching between the "adjustment mode" and the "measurement mode" is provided below the display changeover switch 16.

Each time the setting changeover switch 34 is depressed once, the display content of the numerical value display section 1D is, for example, the second high pressure alarm pressure PH2 (actual pressure: MPa) → SP detection set value PSP (kPa / 100 ms). ) → 1st gas pressure check pressure PM1
(MPa (at 20 ° C) → 2nd gas pressure check pressure PM2
(MPa (at 20 ° C) → initial filling pressure PG (MPa
(At 20 ° C)) → 1st high pressure alarm pressure PH1 (MPa
(At 20 ℃)) → Gas leak alarm pressure PL1 (MPa
(At 20 ° C)) → Operation locking pressure PL2 (MPa (at
20 ° C.)), and returns to the display of the second high pressure alarm set value PH2 again. For setting values other than the setting values set by the trimmers 35 to 37, when the setting change switch 34 is pressed for 5 seconds or more while the set values are being displayed, the set value change mode is set. The switch 33 and the setting switch 34 are assigned to an “ENT key”, an “up key”, and a “down key”, and the setting values can be updated by operating these keys.

FIG. 10 is a schematic block diagram of the pressure relay 1. The pressure relay 1 outputs a voltage drop detection signal when the power supply voltage (+ 5V) drops to a predetermined value (CMOS-iC is functioning) in addition to the power-on reset function, in addition to the above-described elements such as the LED and the switch. A power-on reset circuit 41 for outputting a watchdog timer signal SWDT for outputting a second-order reset by detecting that a control unit 48 described later has fallen out of control without following a processing program; Timer 42
And a pressure / voltage converter (P / V converter) 43 that converts the original pressure detection signal SPO output from the pressure sensor 25 into an original pressure voltage signal SVPO that is a voltage signal and outputs the converted signal, and a temperature sensor 26 outputs. A temperature / voltage converter (T / V converter) 44 for converting the original temperature detection signal STO into an original temperature voltage signal SVTO which is a voltage signal and outputting the converted signal is provided. A function selector 45 having a short-circuit pin 45a for switching between an “adjustment mode” for adjusting various set values according to the GIS 2 to which the pressure relay 1 is attached and a “measurement mode” which is an operation state after installation. , A high-pressure alarm setting unit 35 'including the trimmer 35, a gas leak alarm setting unit 36' including the trimmer 36, and an operation lock setting unit 37 'including the trimmer 37.

In addition, data is saved at the time of a voltage drop to prevent data loss, and a fixed set value of the ROM, a changed value thereof, or a set value by a trimmer is stored, and the data such as the set value is referred to at the time of power-on reset. E to do
An EPROM 46, a predetermined time near dawn, for example, one hour before dawn, a calendar clock 47 backed up by a lithium battery when the power is turned off, and a control unit 48 for controlling the entire pressure relay 1 , 7 segment display 32a, LED 32
b, a driving digit selecting circuit 49A and an LED driving circuit 49B for controlling the driving of the LEDs 15a to 15g.

Further, a fuse element blowing section 51 for securing safety around the GIS by cutting off the power supply when an output section for driving a relay switch described later is abnormal or when the control section 48 runs away, A high-voltage alarm relay switch 56 based on the high-voltage alarm control signal SHE
A high-pressure alarm output section 52 for outputting a high-pressure alarm output signal SCHE for driving the motor and a gas pressure check request output signal SCME for driving a gas pressure check request relay switch 57 based on the gas pressure check request control signal SME. A gas pressure check request output section 53 for outputting a gas leak alarm output signal SCLE for driving a gas leak alarm relay switch 58 based on the gas leak alarm control signal SLE; An operation lock output section 55 for outputting an operation lock output signal SCLC for driving the operation lock relay switch 59 based on the lock output control signal SLC.

An insulated DC / DC converter 61 for reducing the voltage of an external DC power supply to a predetermined internal power supply voltage of +12 V, and a power supply for reducing the output voltage (+12 V) of the insulated DC / DC converter 61 to +5 V An iC62, a power supply iC63 for similarly stepping down from + 12V to + 8V, and a terminal block 64 on which the terminal 14 for connecting to an external DC power supply (not shown) or the corresponding electric device circuit operation unit 10 are provided.

Here, the insulation type DC / DC converter 61
In the above, the input diode prevents damage to the circuit due to reverse connection of the power supply, and may be a bridge diode. The aluminum electrolytic capacitor stabilizes the operation of the converter. Since there is no so-called "ripple" because of DC100V input, "long life" can be secured. The ceramic capacitor in the output section is used instead of the conventional aluminum electrolytic capacitor. This capacitor has a lot of "ripple" during rectification, and the conventional aluminum capacitor has a limited life (up to several years). However, by using this ceramic capacitor, the life is dramatically extended. The circuit voltage +12 V is used for display and relay driving, +8 V is used for analog circuits, and +5 V is used for digital circuits such as microcomputers.

The control unit 48 is composed of a microcomputer or the like, and includes a control unit 48a for controlling the entire control unit 48, an operation unit 48b for performing various operations, and a comparison unit 48c for performing various comparisons. A determination unit 48d for making various determinations based on a comparison result in the comparison unit 48c;
Timer unit 48e for generating a 5 msec interrupt signal for executing detection by interrupt processing, A / D converter 48f for performing analog / digital conversion of an input analog signal, and RAM for temporarily storing various data , And a storage unit 48h composed of a ROM storing a control program and various data. The control unit 48
Functions such as a, the operation unit 48b, the comparison unit 48c, and the determination unit 48d are realized by a CPU constituting the microcomputer and a control program described later executed by the CPU.

The control unit 48 includes a driving digit selection circuit 4
9A and the LED drive circuit 49B, the fuse element blowing section 51, and a high-pressure alarm control signal SHE to the high-pressure alarm output section 52 in accordance with the results of the various determinations. , A gas leak alarm control signal SLE to the gas leak alarm output unit 54, and an operation lock output control signal SLC to the operation lock output unit 55. The high-pressure alarm control signal SHE is also output during self-diagnosis and SP detection in addition to the two high-pressure alarms. That is, the logical sum of the four types of alarms is obtained. The gas pressure check request control signal SME is output at the time of the first and second gas pressure check requests. That is, the logical sum of the two types of inspection requests is obtained.

The high-voltage alarm relay switch 56 is turned on when the high-voltage alarm output signal SCHE is output from the high-voltage alarm output section 52, and the terminal block 64 is closed between the terminals “H3” and “C3”. Is done. The gas pressure check request relay switch 57 is turned on when a gas pressure check request output signal SCME is output from the gas pressure check request output section 53, and both terminals of the terminal “L0” and the terminal “C0” of the terminal block 64 are turned on. The interval is closed. The gas leak alarm relay switch 58 is turned on when the gas leak alarm output signal SCLE is output from the gas leak alarm output section 54, and the terminals L1 and C1 of the terminal block 64 are closed. Is done. When the gas leak alarm relay switch 58 is off, the terminal block 6
4, the terminal between "H1" terminal and "C1" terminal is closed. The operation lock relay switch 59 is turned on when the operation lock output signal SCLC is output from the operation lock output unit 55, and both terminals of the “L2” terminal and the “C2” terminal of the terminal block 64 are closed. Is done. The state shown in FIG. 10 in each relay switch is an ON state in which the back contact is closed when power is not supplied to the pressure relay 1.

FIG. 11 is a view showing a wiring state of the terminal block 64. The terminal of "ground" is grounded together with the electric equipment circuit operation unit 10, and the terminal of "DC-" and the terminal of "DC +" are connected to the electric equipment. D from the circuit operation unit 10 to the pressure relay 1
The power of C100V is supplied. "H3", "C
3 "," L1 "," C1 "," H1 "," L2 "," C
The terminal “2” is connected to the electric device circuit operation unit 10 as it is, but the terminal “L0” is connected to the terminal “L1”, and the terminal “C0” is connected to the terminal “C1”. . As a result, the gas pressure check request signal and the gas leak alarm signal are logically ORed and output in a hardware manner, and the number of wirings can be reduced when the GIS is installed on an existing GIS. .

FIGS. 12 to 16 are flowcharts of a control program of the CPU constituting the microcomputer of the control unit 48. FIGS. 12 to 14 are flowcharts of a main routine, FIG. 15 is a flowchart of an interrupt process, and FIG. It is a flowchart of a subroutine of an input process. Hereinafter, the operation will be described based on the flowchart. In the following description and each flowchart, each register and flag used for control are represented by the following labels, and each register and flag and their storage contents are represented by the same label unless otherwise specified.

[0068] Pt: SF ₆ register t of the detected pressure of the gas (actual pressure): SF ₆ detects the temperature of the registers of the gas P20: Temperature compensation register pressure PG: register setting value of the initial filling pressure of SF ₆ gas PH1: Register of the set value of the first high-pressure alarm pressure PH2: Register of the set value of the second high-pressure alarm pressure (actual pressure) PL2: Register of the set value of the operation lock pressure PL1: Register of the set value of the gas leak alarm pressure PM1: Register of first set value of gas pressure check pressure PM2: Register of second set value of gas pressure check pressure t2, t1: Register of duty ratio of blinking of gas pressure check request signal

The CPU is turned on by the power-on reset as shown in FIG.
When the process of the main routine is started, first, an initialization process-1 is performed in step S1. In this initialization process-1, the storage unit (RAM) 48g is all cleared and the data in the EEPROM 46 is referred to, and all the data is "00h"("h" indicates a hexadecimal number) or "FFh". In the case of, the storage unit (ROM) 48h
Of the storage unit 48g and E
It is stored in the EPROM 46. When the initialization process-1 is completed, the process proceeds to step S2.

On the other hand, when the watchdog timer starts, initialization processing-2 is performed in step S1 '. In this initialization process-2, a part of the storage unit (RAM) 48g is cleared, and the set values of the EEPROM 46 are retained. When the initialization process-2 is completed, step S
Proceed to 2.

In step S2, it is determined whether or not the measurement mode (open) is selected according to the state of the short-circuit pin 45a of the function selection section 45. If not, the measurement mode is the adjustment mode (short circuit). At step S3, the temperature compensation pressure P is displayed by the numerical display 1D and the LEDs 15a and 15b.
20, the detected pressure Pt and the detected temperature t are blinked and displayed in sequence, and the process proceeds to step S5. Note that this adjustment mode is a mode of adjustment work when the pressure relay 1 is inspected before shipment.
Each display value is displayed as one digit more numerical value so that fine adjustments can be made. When the adjustment is completed, the short-circuit pin 45a of the function selecting section 45 is opened to set the "measurement mode". On the other hand, in the measurement mode, the display of the numerical value display section 1D is displayed as the temperature compensation pressure P20 in step S4, and the process proceeds to step S5. In step S5, the timer unit (5 msec timer) 48e is activated and the interruption is permitted.

Next, at step S6, the A / D converter 48f
, The data of the gas temperature t is read, and it is determined in step S7 whether or not the gas temperature t is in the range of −30 ° C. to 70 ° C. If the temperature is not within the range of -30.degree. C. to 70.degree. As a result, when the gas temperature is abnormal, an alarm is issued and the apparatus stands by until a key input or the like is made after restoration. The process corresponding to the key input after the restoration is a process for returning to the main routine, and a detailed description thereof will be omitted. If the temperature is in the range of −30 ° C. to 70 ° C., the detected pressure (actual pressure) Pt and the gas temperature t are determined in step S9.
Temperature compensation pressure P20 is calculated based on
Go to 0. The calculation of the temperature compensation pressure P20 is performed by, for example, calculating the detected pressure Pt based on the gas temperature t using a constant molar volume curve (or an approximate straight line) representing the gas pressure at a constant molar volume as a function of temperature. P20
Convert to

Next, at step S10, the temperature compensation pressure P20 is displayed on the numerical value display section 1D, and at step S11, it is determined whether or not the temperature compensation pressure P20 is equal to or higher than the first high-pressure alarm pressure PH1. If not, in step S12, the high-pressure alarm control signal SHE is not output to the high-pressure alarm output unit 52, and the high-pressure alarm relay switch 56 is turned off. Then, the process proceeds to step S14. The high-voltage alarm control signal SHE is output to the unit 52 to turn on the high-voltage alarm relay switch 56, and the process proceeds to step S14. When the high-voltage alarm relay switch 56 is turned on / off, abnormality diagnosis is performed at the same time.

In step S14, the temperature compensation pressure P20
Is less than or equal to the gas pressure check pressure (second set value) PM2, and if not, the gas pressure check request output unit 53 is supplied with the gas pressure check request control signal SME in step S15. With no output, the gas pressure check request relay switch 57 is turned off, and the process proceeds to step S18 in FIG. If not more than PM2, then in step S16 (PG-P2
0) / (PG-PL1) is calculated as the blinking duty ratio t2, and in step S17, the gas pressure check request output unit 5
A gas pressure check request control signal SME is output in response to the duty ratio t2 with respect to No. 3, and the gas pressure check request relay switch 57 is repeatedly turned on / off at a cycle of 1 second. That is, the gas pressure check request control signal SME is output so as to be turned on for t2 seconds and turned off for (1-t2) seconds. Also,
In response to this on / off, L for displaying a gas pressure check request is displayed.
The ED 15d also blinks.

Next, at step S18 in FIG. 13, it is determined whether or not the temperature compensation pressure P20 is equal to or lower than the gas leak alarm pressure PL1, and if not, the gas leak alarm output unit 54 is determined at step S19. Gas leak alarm control signal SLE
Gas leak alarm relay switch 5
8 and then goes to step S21. If it is equal to or less than PL1, a gas leak alarm control signal SLE is output to the gas leak alarm output section 54 in step S20, and the gas leak alarm relay switch 58 is turned on to go to step S21. move on.

At step S21, the temperature compensation pressure P20
Is not equal to or less than the operation lock pressure PL2. If not, the operation lock output control signal SLC is not output to the operation lock output unit 55 in step S22. Step S after turning off the relay switch 59
If it is not more than PL2, the operation lock output control signal SLC is output to the operation lock output unit 55 in step S23 to turn on the operation lock relay switch 59, and the flow proceeds to step S24.

In step S24, the calendar clock 47
Thus, for example, it is determined whether or not the time has reached one hour before dawn. If the time has not reached one hour before dawn, the process proceeds to step S31. If the time has reached one hour before dawn, the process proceeds to step S25. In addition, the time of dawn differs according to the area where the GIS is installed, and varies with the season. For example, since the average time is determined for each month, the time of dawn for each month is stored in advance. OK, calendar clock 4
It is preferable to set a range of one hour before dawn according to seven possible months.

In step S25, the temperature compensation pressure P20 is obtained every 10 minutes, and the average value of the seven temperature compensation pressures P20 is calculated. In step S26, the calculated average value is stored in the storage unit (RAM) 48g, for example. Seven average values are sequentially stored in the ring buffer together with the average values for the six days up to the previous day. Next, in step S27, the average value of the average value for seven days in the storage unit 48g is calculated, and the average value is set as the average temperature compensation pressure <P20>. Then, in step S28, it is determined whether or not the average temperature compensation pressure <P20> is equal to or less than the gas pressure check pressure (first set value) PM1.
If it is not M1 or less, the process proceeds to step S31, and if it is PM1 or less, (PG- <P20>) / (PG
−PL1) is calculated as the blinking duty ratio t1,
In step S30, a gas pressure check request control signal SME is output to the gas pressure check request output section 53 in accordance with the duty ratio t1, and the gas pressure check request relay switch 57 is repeatedly turned on / off at a cycle of 1 second. That is, the gas pressure check request control signal SME is output so as to be turned on for t1 seconds and turned off for (1-t1) seconds. In addition, the LED 15d for displaying the gas pressure check request is also blinked in response to the on / off operation.

Next, at step S31, the return switch 33
It is determined whether or not has been pressed, and if it has not been pressed, the process proceeds to step S33, and if it has been pressed, at step S32,
With the gas pressure check request control signal SME not output to the gas pressure check request output section 53, the gas pressure check request relay switch 57 is turned off, and the routine proceeds to step S33.

In step S33, the key input processing of FIG. 16 is performed as described later. When this key input processing is completed, it is determined in step S34 of FIG. 14 whether or not the time is an odd multiple of 10 minutes. If it is an odd multiple, step S3
At 5, the abnormality diagnosis of the P / V converter 43 is performed, and the process returns to step S6 of FIG. If the time is not an odd multiple of 10 minutes in step S34, it is determined whether or not the time is an even multiple of 10 minutes in step S36. If not, the process returns to step S6 of FIG. If T in step S37
The abnormality diagnosis of the / V converter 44 is performed, and the process returns to the step S6 in FIG.

The interrupt processing of FIG.
In step S41, the timer unit 48e is restarted for the next interrupt. In step S42, the detected pressure (actual pressure) Pt is read from the A / D converter 48f. In S43, the detected pressure Pt is −0.101 MPa to 1.00.
It is determined whether it is within the range of 0 MPa, and if it is out of the range, in step S44, a self-diagnosis abnormal signal output process is performed and a standby state is set (Wait). As a result, when the detected pressure is abnormal, an alarm is issued, and the process stands by until a key input or the like is made after restoration. If the gas pressure Pt is within the range, in step S45, the read detection pressure Pt is stored in the storage unit 48g together with the detection pressure Pt of the predetermined sampling number up to the previous time stored in the storage unit 48g.
Are sequentially stored in the storage unit 4 in step S46.
SP detection processing is performed based on the pressure rise rate and the like from the plurality of detected pressures Pt stored in 8g, and the process proceeds to step S47. When the impact pressure is detected in the SP process, a high-pressure alarm control signal SHE is output to the high-pressure alarm output unit 52 to turn on the high-pressure alarm relay switch 56 to output an alarm.

In step S47, the detected pressure Pt is set to the second
It is determined whether or not the pressure is equal to or higher than the high-pressure alarm pressure PH2. If the pressure is not equal to or higher than PH2, the high-pressure alarm control signal SHE is not output to the high-pressure alarm output unit 52 in step S48 and the high-pressure alarm relay switch 56 is turned off. And return to the original routine. If the detected pressure Pt is equal to or higher than PH2, step S4
9, the high-voltage alarm control signal SHE is sent to the high-voltage alarm output unit 52.
Is output to turn on the high-voltage alarm relay switch 56 and return to the original routine.

In the key input processing of FIG. 16, step S5
In step 1, it is determined whether or not the setting switch 34 has been pressed.
If it has not been pressed, the process proceeds to step S56. If it has been pressed, in step S52, the set value is displayed on the numerical value display section 1D as described above, and the LEDs 15a and 15b perform unit display and output display. This display is turned on for 0.5 seconds, turned off for 0.5 seconds, and flashes slowly. Next, in step S53, it is determined whether or not the setting switch 34 has been pressed for 5 seconds or more. If the switch has not been pressed for 5 seconds or more, the process proceeds to step S56. If it has been pressed for 5 seconds or more, the process proceeds to step S54. , Display switch 16 is set to "ENT key"
Then, the return switch 33 is assigned to the "up key", and the setting changeover switch 34 is assigned to the "down key". Next, in step S55, corresponding set values (PH1, PL1, PL2) are read from the states of the trimmers 35, 36, 37 and set.

Next, in step S56, it is determined whether or not the display changeover switch 16 has been pressed. If the switch has not been pressed, the process proceeds to step S60. If it has been pressed, the process proceeds to step S57.
, The detected pressure Pt is lit on the numerical value display section 1D, and the LED 15a blinks slowly to display the actual pressure.
Proceed to step S58. In step S58, it is determined whether or not the display changeover switch 16 has been pressed. If the switch has not been pressed, the process proceeds to step S60. If the switch has been pressed, the detected temperature t is illuminated and displayed on the numerical value display section 1D in step S59. Then, the LED 15b is made to blink slowly so as to display the unit of temperature, and the process proceeds to step S60.

In step S60, the display of the numerical value display section 1D is returned to the display of the temperature compensation pressure P20, and step S61 is performed.
It is determined whether or not the return switch 33 has been pressed, and if not, the process returns to the original routine.
In step S62, the standby state (Wait) is released, and the process returns to the original routine.

By the above processing, as shown in FIG. 17, the detected pressure (actual pressure) Pt is changed to the second high pressure alarm pressure PH2.
(0.90 MPa), "C3" and "H
3 "is turned off (open), and when the detected pressure Pt reaches the second high pressure alarm pressure PH2, both terminals of" C3 "and" H3 "are turned on (closed), and the electrical equipment circuit is turned on. Operation unit 1
Operation corresponding to the high pressure alarm can be performed at 0.

Further, as shown in FIG. 18, when the temperature compensation pressure P20 is lower than the first high pressure warning pressure PH1 (0.70 MPa), the terminals between "C3" and "H3" are turned off (open). When the temperature compensation pressure P20 reaches the first high pressure alarm pressure PH1, the terminals between "C3" and "H3" are turned on (closed), and the electric device circuit operation unit 10 responds to the high pressure alarm. Can operate. When the temperature compensation pressure P20 is higher than the gas pressure check pressure PM1 (0.49 MPa), the terminals between "C0" and "L0" are turned off (open). C0 ”and“ L
"0" is turned on / off according to the duty ratio. Further, the temperature compensation pressure P20 is equal to the gas pressure check pressure PM2.
(0.475 MPa), "C0" and "L
"0" is turned on / off according to the duty ratio at that time.

When the temperature compensation pressure P20 is higher than the gas leak alarm pressure PL1 (0.45 MPa), "C1"
When the temperature compensation pressure P20 becomes lower than the gas leak alarm pressure PL1 when the temperature between the two terminals L1 and L1 is turned off (open), "C
The terminals between “1” and “L1” are turned on (closed), and the electric device circuit operation unit 10 can perform an operation corresponding to the gas leak alarm. Further, the temperature compensation pressure P20 is equal to the operation lock pressure PL2.
(0.40 MPa), "C2" and "L
2 ”is turned off (open) between both terminals, and the temperature compensation pressure P
When the pressure 20 becomes lower than the operation lock pressure PL2, "C2" and "L
2 "is turned on (closed), and the operation corresponding to the operation lock can be performed by the electric device circuit operation unit 10.

FIG. 19 is a diagram showing an example of the duty ratio of the first and second gas pressure check request signals. FIG. 19 (A) shows that the temperature compensation pressure P20 decreases to the first gas pressure check pressure PM1. FIG. 19B shows the case where the temperature compensation pressure P20
Has decreased to the second gas pressure check pressure PM2. That is, the duty ratio, which is the degree of the gas pressure drop, is the initial filling pressure PG (0.50 MPa) and the gas leak alarm pressure PL1 (0.45MPa) corresponding to the low pressure side control limit.
a) the initial filling pressure PG (0.
50 MPa) and the temperature compensation pressure P20. In the case of FIG. 19A, 0.01 / 0.05 = 0.
2. In the case of FIG. 19B, 0.025 / 0.05 = 0.
It becomes 5. Then, the degree of the gas pressure drop can be confirmed by the LED 15d which blinks according to the duty ratio.

As shown in FIG. 20, the temperature compensating pressure P20 for determining the gas pressure check request is determined by, for example, obtaining an average value of seven values sampled within one hour before dawn and calculating the average value. This is a value obtained by moving average the values for 7 days, so the detected pressure is also a stable value due to the stable temperature before dawn, and the difference between days can be reduced. , A small decrease in gas pressure can be detected with high accuracy.

[0091]

According to the pressure monitoring apparatus for an electrically insulating gas according to the first or second aspect of the present invention, a pressure vessel equipped with a GIS, for example, a density switch, regardless of whether it is new or existing, is installed. The connection pipe section can be connected to a pressure introduction pipe, a check can be prompted to a monitor by a gas pressure check request signal, and a gas leak to the atmosphere can be prevented as much as possible. Since the function of the output density switch and the like can be maintained, it is possible to accurately detect a small decrease in gas pressure at an early stage and to prevent gas leakage to the atmosphere as much as possible.

According to the third aspect of the present invention, in addition to the function and effect of the first or second aspect, the gas pressure detecting means detects the gas pressure based on the temperature compensation pressure. Since the detection is performed, the influence of the temperature difference can be reduced and the minute gas pressure drop can be accurately detected.

According to the pressure monitoring apparatus for an electrically insulating gas according to the fourth aspect of the present invention, in addition to the functions and effects of the third aspect,
Since the pressure sensor and the temperature sensor are a composite sensor having the same structure, assembly and arrangement can be easily performed.

According to the pressure monitoring apparatus for an electrically insulating gas according to the fifth aspect of the present invention, in addition to the functions and effects of the third and fourth aspects, the temperature sensor is located adjacent to the pressure sensor. The accuracy of detecting the temperature of the electrical insulating gas whose pressure is detected by the sensor is improved.

According to the pressure monitoring apparatus for an electrically insulating gas according to claim 6 of the present invention, in addition to the effects of claim 1, claim 2, or claim 3, the degree of decrease in gas pressure can be determined in two stages. I can judge.

According to the pressure monitoring apparatus for an electrically insulating gas according to the seventh aspect of the present invention, in addition to the functions and effects of the sixth aspect, the first and second gas pressure check request signals are one type of signal. Therefore, the output can be performed from one output terminal, and the installation can be facilitated.

According to the pressure monitoring apparatus for an electrically insulating gas according to the eighth aspect of the present invention, in addition to the functions and effects of the first and second aspects, a gas pressure check request signal and the gas leak alarm signal are output. Output terminal can be shared with existing GI
The installation in S can be made particularly easy.

According to the pressure monitoring apparatus for an electrically insulating gas according to the ninth aspect of the present invention, in addition to the functions and effects of the first, second, third, or sixth aspects, a gas pressure check request signal is also provided. Identification becomes easy.

According to the pressure monitoring apparatus for an electrically insulating gas according to the tenth aspect of the present invention, in addition to the functions and effects of the ninth aspect,
The degree of gas pressure drop can be confirmed by the blinking duty ratio, that is, the manner of blinking.

According to the eleventh aspect of the present invention, in addition to the functions and effects of the tenth aspect, the gas pressure drop in the pressure range between the initial filling pressure and the gas leak alarm pressure is obtained. Can be checked.

According to the pressure monitoring apparatus for an electrically insulating gas according to the twelfth aspect of the present invention, the accuracy of the temperature compensation pressure is increased, and a small decrease in gas pressure can be accurately detected by the stable temperature compensation pressure. Yes, and since the average of a plurality of days is taken, even if there is an abnormal climate day, the difference between the days can be reduced.

According to the pressure monitoring apparatus for an electrically insulating gas according to the thirteenth aspect of the present invention, in addition to the functions and effects of the twelfth aspect, it follows a gradual temperature change over a long period of time, for example, a change in the average temperature every season. It is possible to accurately detect a small decrease in gas pressure.

According to the pressure monitoring apparatus for an electrically insulating gas described in claim 14 of the present invention, claim 12 or 13 is provided.
In addition to the effects of the above, before dawn, since the outside air temperature is in a substantially equilibrium state, the temperature compensation pressure as an average value becomes a stable value, and a minute gas pressure drop can be detected accurately.

According to the pressure monitoring apparatus for an electrically insulating gas described in claim 15 of the present invention, claim 12 or claim 13 is provided.
In addition to the effects of the fourteenth aspect, the pressure monitoring device can be easily assembled at the time of manufacture, can be easily installed on a GIS or the like, and further, the accuracy of detecting the temperature of the electrically insulating gas can be increased, and the calculation can be further performed. The accuracy of the temperature compensation pressure is also increased.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a pressure relay and a GIL according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a mounting state of a pressure relay according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a set value according to the embodiment of the present invention.

FIG. 4 is an external front view of the pressure relay according to the embodiment of the present invention.

FIG. 5 is an external bottom view and an external side view of the pressure relay according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view of a pressure / temperature detecting unit according to the embodiment of the present invention.

FIG. 7 is a plan view of a sensor chip according to the embodiment of the present invention.

FIG. 8 is a circuit diagram of a pressure sensor and a temperature sensor according to the embodiment of the present invention.

FIG. 9 is a front view showing a state where a front case of the pressure relay according to the embodiment of the present invention is removed.

FIG. 10 is a schematic configuration block diagram of a pressure relay according to an embodiment of the present invention.

FIG. 11 is a diagram showing a wiring state of a terminal block in the embodiment of the present invention.

FIG. 12 is a flowchart of a main routine of a control program according to the embodiment of the present invention.

FIG. 13 is another part of the flowchart of the main routine of the control program in the embodiment of the present invention.

FIG. 14 is yet another part of the flowchart of the main routine of the control program in the embodiment of the present invention.

FIG. 15 is a flowchart of an interrupt process of a control program according to the embodiment of the present invention.

FIG. 16 is a flowchart of a key input process of a control program according to the embodiment of the present invention.

FIG. 17 shows a detected pressure (actual pressure) in the embodiment of the present invention.
FIG. 4 is a diagram for explaining a state between terminals by means of a second high-alarm pressure.

FIG. 18 shows a temperature compensation pressure according to the embodiment of the present invention;
It is a figure explaining the state between terminals by the 1st high pressure alarm pressure, gas pressure check pressure, gas leak alarm pressure, and operation locking pressure.

FIG. 19 is a diagram illustrating an example of a duty ratio of first and second gas pressure check request signals according to the embodiment of the present invention.

FIG. 20 is a diagram showing a change in gas pressure and a sampling time of a temperature compensation pressure in the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 pressure relay (pressure monitoring device) 2C pressure vessel 3 pressure introduction pipe 4 output signal line 11 connection pipe section 12 front case 13 back case 14 terminal 15c LED for high pressure alarm display 15d LED for gas pressure check request display 15e Gas leak LED for alarm display 15f LED for operation lock alarm display 16 Display changeover switch 17 Pressure / temperature detection unit 47 Calendar clock (24-hour timer) 48 Control unit (microcomputer) 53 Gas pressure check request output unit 57 Gas pressure check request Relay switch 61 Insulated DC / DC converter 64 Terminal block

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seiichi Nakahara 535 Sasai, Sayama-shi, Saitama F-term (reference) 5G017 DD12 EE04 EE05 5G028 AA03 AA07 AA24 GG18 GG21

Claims (15)

[Claims] 1. A connecting pipe portion connectable to a pressure introducing pipe of a pressure vessel in which an electric insulating gas is sealed, and detecting a gas pressure of the electric insulating gas in the pressure vessel through the connecting pipe portion. Gas pressure detecting means, and a gas pressure check pressure on a low pressure side near an initial filling pressure of the electric insulating gas is set higher than a gas leak alarm pressure corresponding to a low pressure side control limit of the electric insulating gas; First control means for outputting a gas pressure check request signal when the gas pressure detected by the detection means becomes the gas pressure check pressure; and gas detected by the gas pressure detection means, wherein the gas leak alarm pressure is set. A second control means for outputting a gas leak alarm signal when the pressure becomes lower than the gas leak alarm pressure, the pressure monitoring device for an electrically insulating gas. 2. An output terminal for outputting the gas pressure check request signal and the gas leak alarm signal, wherein the gas pressure detecting means, the first control means, and the second control means are housed in one case. 2. The pressure monitoring device according to claim 1, wherein the output terminal is provided on the case. 3. The gas pressure detecting means includes a pressure sensor for detecting a pressure of the electric insulating gas, and a temperature sensor for detecting a temperature of the electric insulating gas, the gas pressure being detected by the gas pressure detecting means. 3. The gas pressure according to claim 1, wherein the gas pressure is a temperature compensation pressure obtained by converting a pressure detected by the pressure sensor into a standard temperature pressure based on a temperature detected by the temperature sensor. 4. Pressure monitoring device for electrical insulation gas. 4. The pressure monitoring apparatus according to claim 3, wherein the pressure sensor and the temperature sensor are a composite sensor having the same structure. 5. The pressure sensor and the temperature sensor are a pressure sensor using a piezoresistive element in a portion distorted by pressure change on the same diaphragm and a temperature sensor using a piezoresistive element in a portion not distorted by pressure change. The pressure monitoring device for gas for electrical insulation according to claim 3 or 4, wherein 6. The first control means, which outputs a gas pressure check request signal when the gas pressure detected by the gas pressure detection means reaches the gas pressure check pressure, comprises a gas detected by the gas pressure detection means. When the pressure becomes lower than a first predetermined set value which is set to a lower pressure side than the vicinity of the initial filling pressure of the electric insulating gas, a first gas pressure check request signal is output and detected by the gas pressure detecting means. When the set gas pressure becomes lower than a second predetermined set value set near the average value of the gas leak alarm pressure and the initial filling pressure of the electric insulating gas, a second gas pressure check request signal is output. The pressure monitoring device for an electrically insulating gas according to claim 1, wherein the pressure is monitored. 7. The gas pressure check request signal, wherein the first gas pressure check request signal and the second gas pressure check request signal are logically ORed and output as a gas pressure check request signal.
A pressure monitoring device for an electrically insulating gas as described in the above. 8. The pressure monitoring apparatus according to claim 1, wherein the gas pressure check request signal and the gas leak alarm signal are output in parallel. 9. The gas pressure check request signal is a switch output, and is a blinking signal that is alternately switched between open and closed or on and off. The pressure monitoring device for an electrically insulating gas according to claim 6. 10. The gas pressure monitoring device according to claim 9, wherein the gas pressure check request signal is a blinking signal in which a degree of a decrease in gas pressure corresponds to a blinking duty ratio. 11. The degree of the gas pressure drop is defined as a difference between an initial sealing pressure of the electric insulating gas and a gas leak alarm pressure corresponding to a low pressure side control limit of the electric insulating gas.
The pressure monitoring device for an electrically insulating gas according to claim 10, wherein the degree is determined by a difference between an initial filling pressure and a gas pressure detected by the gas pressure detecting means. 12. A pressure sensor for detecting a pressure of an electric insulating gas sealed in a pressure vessel, a temperature sensor for detecting a temperature of the electric insulating gas, and a temperature sensor for detecting a pressure detected by the pressure sensor. Pressure detection means for obtaining a temperature compensation pressure converted to a standard temperature pressure based on the temperature detected in the above, the electric insulation gas higher than the gas leak alarm pressure corresponding to the low pressure side control limit of the electric insulation gas A gas pressure check pressure based on a first predetermined set value is set to a lower pressure side than near the initial filling pressure, and when the temperature compensation pressure becomes lower than the gas pressure check pressure based on the first predetermined set value, a first gas pressure is set. Control means for outputting a check request signal, wherein the control means sets the temperature at a predetermined time on a plurality of days as the temperature compensation pressure to be compared with the gas pressure check pressure according to the first predetermined set value. Pressure monitoring device for an electric insulation gas which is characterized by using the average value of the compensation pressure. 13. The system according to claim 12, wherein the average value of the temperature compensation pressure is a value obtained by moving average over a predetermined number of days.
A pressure monitoring device for an electrically insulating gas as described in the above. 14. The electricity according to claim 12, wherein the temperature compensation pressure at the predetermined time is an average value of a plurality of temperature compensation pressures detected during a predetermined time near dawn. Pressure monitoring device for insulating gas. 15. The pressure sensor and the temperature sensor,
A composite sensor having the same structure, wherein the pressure sensor on the same diaphragm is distorted by a pressure change by a piezoresistive element, and a temperature sensor by a piezoresistive element on a portion not distorted by the pressure change. The pressure monitoring device for an electrically insulating gas according to claim 12 or claim 13.