JP2662678B2 - Sulfur hexafluoride gas-filled load switch with gas monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention, sulfur hexafluoride is an excellent negative gas and electrical insulation (hereinafter, abbreviated as SF ₆₎ an oxygen gas concentration in the load break switch which gas is sealed detecting and warning, to a gas monitoring apparatus with SF ₆ gas filled load break switch which monitors the filling gas concentration by performing a warning display or the like.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a conventional SF ₆ gas-filled load switch with a gas monitoring device disclosed in Japanese Patent Publication No. 64-3304, and FIG. 7 is a cross-sectional view of the gas monitoring device of FIG. It is. In the figure, 1 denotes an inert gas (SF ₆
Gas, etc.), a movable contact 2 for disposing an opening and closing operation, and a movable contact 3 for opening and closing, and a bushing 4 fixed below the outside of the closed container 1 and an outside of the closed container 1. This is a movable terminal connected to equipment (not shown).

A fixed contact 5 is disposed at a position facing the movable contact 2 and is electrically connected to the movable contact 2 by mechanical connection. A bushing 7 is provided above the outside of the closed container 1. And is a fixed terminal connected to an external device (not shown) outside the sealed container 1.

[0004] Numeral 8 denotes a drive shaft for pivotally connecting the movable contact 2 and a drive shaft for moving the attached movable contact to make mechanical contact with each fixed contact 5.
, A drive lever for operating the drive shaft 8,
A lock mechanism device 0 is interposed between the drive lever 9 and the drive shaft 8 and locks the operation of the drive lever 9.

[0005] Reference numeral 11a denotes an inert gas (SF) in the closed container 1.
_The gas monitoring device locks the lock mechanism device 10 when the property change (purity change of the sealed SF ₆ gas) is detected and monitored, and the gas monitoring device 12 is provided outside the sealed container 1 to monitor the gas. This is an alarm display device that issues an alarm when the device 11a is abnormal.

Reference numeral 13 denotes a substantially rectangular parallelepiped casing having a large number of holes 13a formed therein. Reference numeral 14 denotes a fixed contact provided inside the casing 13 and formed of a switching member.
Reference numeral 5 denotes a fixed-side conductor that is connected to the fixed contact 14 and extends to the outside of the casing 13, and is connected to the lock mechanism device 10 and the alarm display device 12.

Reference numeral 16 denotes a movable contact which is disposed at a position opposed to the fixed contact 14 and contacts the bent fixed contact 14 when the amount of oxygen accumulated due to leakage of air increases. Reactive substance 16 consisting of phosphorus, antimony, etc., which has an exothermic reaction with oxygen.
a, a first metal member 16b made of a bimetal which is a heat-responsive element having a large number of holes H adhered to one surface of the reactive substance 16a, and a reactive member at a position facing the fixed contact 14. The second metal member 16c is made of a bimetal that is a thermoresponsive element having a smaller thermal expansion coefficient than the first metal member 16a. A movable conductor 17 is connected to the second metal member 16c of the movable contact 16 and extends to the outside of the casing 13. The movable conductor 17 is connected to the lock mechanism device 10 and the alarm display device 12.

A conventional SF ₆ gas-filled load switch with a gas monitoring device is constructed as described above, and FIG. 8 is a schematic diagram showing an operation when an abnormality of the gas monitoring device is detected. Hereinafter, the operation will be described.

First, the function as a switch is as follows. When an operator turns on a drive lever 9, the drive shaft 8 operates in the horizontal direction, and the movable contact 2 connected to the drive shaft 8 has a fixed contact. The electrical connection is made in contact with the child 5.
Further, when the drive lever 9 is turned off, the movable contact 2 operates in the opposite direction to the above and is cut off.

By using the above switch for a long period of time, the airtight mechanism of the switch deteriorates, and the sealed SF6 gas pressure, which was initially set to a gauge pressure of 0.15 MPa, becomes atmospheric pressure (0.1 MPa). Down to When the pressure of the charged gas increases and decreases with a change in the outside air temperature, for example, when the internal pressure decreases, air flows from the deteriorated portion into the closed container 1. In this manner, when air flows into the closed container 1, the air contacts the movable contact 16 through the hole 13a of the casing 13 of the gas monitoring device 11a, and the reactive substance 16a of the movable contact 16 becomes free from oxygen in the air. The reaction generates heat. Due to the heat generation, the first and second metal members 16b forming the bimetal with the reactive substance 16a interposed therebetween,
The movable contact 16c is bent by being thermally deformed, and the movable contact 16 and the fixed contact 14 come into contact with each other.

When the movable contact 16 and the fixed contact 14 come into contact with each other, the contact becomes conductive, and the gas monitoring device 11a locks the drive lever 9 of the lock mechanism device 10 and operates the alarm display device 12 to display an alarm and an alarm display. It is supposed to do.

[0012]

In the above-mentioned conventional SF ₆ sealed load switch with a gas monitoring device, since the detection of air entrainment by the reactive substance 16a is based on the accumulation of the amount of air, it is abrupt. There was a problem that it was not possible to respond quickly to the incorporation of air.

Further, the reaction of the reactive substance 16a is poor in reversibility, and when a small amount of gas leakage occurs for a long period of time, even if the concentration of the inert gas in the closed container 1 becomes lower than a predetermined value, it is not detected. However, there has been a problem that a decrease in the electrical insulation of the device cannot be detected.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The present invention is sensitive to a sudden gas, and also sensitive to a small amount of gas leakage over a long period of time. An object of the present invention is to provide a SF ₆ sealed load switch with a gas monitoring device that reliably detects deterioration of a sensor.

[0015]

An SF ₆ gas-filled load switch with a gas monitoring device according to the present invention is provided in a closed container having a switch and filled with sulfur hexafluoride gas, and is provided with a closed container. Detects the concentration of oxygen, which is the impurity gas inside,
A galvanic cell-type oxygen sensor that outputs a voltage proportional to the oxygen concentration, and a voltage corresponding to an oxygen concentration of the minimum condition under which an output value from the galvanic cell-type oxygen sensor can ensure the switching function of the switch is a first reference value. In the above case, when the output value from the alarm output means for outputting the alarm signal and the output value from the galvanic cell type oxygen sensor is smaller than the second reference value corresponding to the oxygen concentration during normal use of the switch, The galvanic cell type oxygen sensor includes a self-diagnosis unit for diagnosing abnormality.

[0016]

According to the present invention, the galvanic cell type oxygen sensor first detects the oxygen concentration in the sealed container and outputs a voltage proportional to the detected oxygen concentration. I do. When the output value from the galvanic cell type oxygen sensor is equal to or more than a predetermined value (first reference value), the alarm output means outputs an alarm signal as an alarm. On the other hand, if the output value from the galvanic cell type oxygen sensor is smaller than another predetermined value (second reference value), the self-diagnosis means added to this means that the galvanic cell type oxygen sensor is abnormal. Diagnose and indicate that continued use of the galvanic oxygen sensor is inappropriate.

[0017]

FIG. 1 is an explanatory diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a circuit diagram showing alarm output means and self-diagnosis output means in FIG. Note that 1 to 10 and 12 are the same as or equivalent to the part numbers of the conventional apparatus described with reference to FIGS.

In FIG. 1, reference numeral 11 denotes a gas leak monitoring device provided in the sealed container 1 of the SF ₆ gas-filled load switch. The gas leak monitoring device 11 changes the output voltage proportionally according to the oxygen concentration. Galvanic cell type oxygen sensor 10
0, the output voltage from the galvanic cell oxygen sensor 100 and one of the reference voltages are input, the alarm output means 200 compares the two voltages and outputs an alarm signal, and the output voltage from the galvanic cell oxygen sensor 100 and the other. Self-diagnosis output means 3 which outputs a self-diagnosis signal by comparing with a reference voltage of
00. Reference numeral 13 denotes a self-diagnosis display device that displays a state in which the galvanic cell type oxygen sensor 100 is normally operating (for example, LED display) based on a self-diagnosis signal from the self-diagnosis output unit 300.

In FIG. 2, reference numerals 201, 202 and 301 are connected in series between a power supply terminal Vcc and a ground potential point, and constitute a reference voltage generating means, respectively, a first resistor and a second resistor.
And the third resistor, and two reference voltages are output to a connection point between the resistors. A reference voltage (referred to as a first reference value) at a connection point between the first resistor 201 and the second resistor 202 can secure the opening and closing function of the movable contact 2 and the fixed contact 5 in the closed container 1. The minimum conditions are, for example, a SF6 gas concentration of 25% in the closed vessel 1,
The output voltage from the galvanic cell type oxygen sensor 100 at the time of the oxygen concentration of 15% and the nitrogen concentration of 60% is set to the same value. On the other hand, the second resistor 202 and the third resistor 30
The reference voltage at the connection point 1 (referred to as a second reference value) is a condition under which the opening and closing function of the movable contact 2 and the fixed contact 5 can be sufficiently ensured in the closed container 1. S
The output voltage from the galvanic cell type oxygen sensor 100 at the time when the F ₆ gas concentration is 98% and the oxygen concentration is 2% is set to the same value.

Reference numeral 203 denotes a first voltage comparator, to which the output voltage from the galvanic cell type oxygen sensor 100 is input to the non-inverting input side +, and the first resistor 20 is connected to the inverting input side.
A reference voltage between the first and second resistors 202 is input,
When the output voltage V0 from the galvanic cell type oxygen sensor 100 is higher than the reference voltage (A.VH), the alarm output means 200 which outputs an H signal (V1 out: see FIG. 4A) is used. And outputs the signal to the lock mechanism device 10 and the alarm display device 12 shown in the operation block diagram of FIG.

Reference numeral 302 denotes a second voltage comparator, which has an inverting input
The output voltage from the galvanic cell type oxygen sensor 100 is input to the non-inverting input and the second resistor 20
Reference voltage (S · VH) between the second and third resistors 301
When the output voltage V0 from the galvanic cell type oxygen sensor 100 is smaller than the reference voltage, an H signal is output (V2 out: see FIG. 4B). And outputs the signal to the gas leak monitoring device 11 shown in FIG.

The SF ₆ sealed load switch with gas monitoring of the present invention is configured as described above. FIG. 3 is an input / output characteristic diagram of a galvanic cell type oxygen sensor, and FIG. 4 is an alarm output means and a self-diagnosis output means. FIG. 5 is an operation block diagram of the present apparatus. Hereinafter, the operation will be described. First, when the operator turns on the drive lever 9 of the switch, the drive shaft 8 is turned on.
Is operated, and the movable contact 2 connected to the drive shaft 8 comes into contact with the fixed contact 5 to make an electrical connection. When the drive lever 9 is turned OFF, the movable contact 2 operates in the opposite direction to disconnect the connection. In this way, the ON / OFF switching operation is repeated, and the normal switching function as a switch operates. However, if the switch is used for a long time and the airtight mechanism of the sealed container 1 is deteriorated due to corrosion, heat cycle, etc., the airtightness is lost.
SF that was initially sealed to a gauge pressure of about 0.15 MPa
The pressure of the _six gases is reduced to the atmospheric pressure of about 0.1 MPa, and the internal pressure in the sealed container 1 is reduced. And
From this point, air flows in and out of the deteriorated portion of the sealed container 1 in the same manner as described in the related art.

Now, assuming that air is mixed in the sealed container 1, the oxygen concentration increases (OX1 → OX2) as shown in FIG. 3 by the galvanic cell type oxygen sensor 100, so that the output voltage also increases proportionally. (V1 → V2). In this case, the output voltage of the galvanic cell type oxygen sensor 100 becomes S
When the reference voltage (A · VH) corresponding to the F ₆ gas concentration of 25% and the air of 75% is exceeded, this output voltage is applied to the non-inverting input + of the first voltage comparator 203 as shown in FIG. As a result, the output voltage at the H level is output to the lock mechanism device 10 and the alarm display device 12, for example, as an alarm signal, as shown in FIG. In this manner, a short-term rapid change in concentration, a long-term cumulative change, and deterioration can be reliably detected. The lock mechanism device 10 locks the drive lever 9 and outputs an alarm and an alarm display from the alarm display device 12 to notify the user. In the galvanic cell type oxygen sensor 100, the oxygen concentration decreases (O
(X2 → OX1) and the reversible characteristic that the output voltage also decreases (V2 → V1), so that it can be easily restored, so that the oxygen sensor is a stable oxygen sensor having a relatively long life.

Next, a self-diagnosis function for detecting long-term deterioration of the galvanic cell type oxygen sensor 100 will be described. When the gas concentration in the closed container 1 is a gas concentration during normal use, for example, when the SF ₆ gas concentration is 98% and the oxygen concentration is 2%, the galvanic cell type oxygen sensor 100 is used.
Generates an output voltage corresponding to the oxygen concentration (2%) as shown in FIG. For this reason, the reference voltage (SV
H), the output voltage value when the SF ₆ gas concentration is 98% and the oxygen concentration is 2% is set, and the reference voltage (S · V
H) is input to the non-inverting input + of the second voltage comparator 302, and the output voltage of the galvanic cell type oxygen sensor 100 is input to the inverting input-. Therefore, when the galvanic cell type oxygen sensor 100 is not deteriorated and the gas concentration in the sealed container 1 is the gas concentration at the time of normal use as described above, the output voltage of the galvanic cell type oxygen sensor 100 Is not lower than the reference voltage (S.VH), the output voltage (self-diagnosis signal) of L level is output from the second voltage comparator 302 as shown in FIG. 13 is output. Then, the self-diagnosis display device 13
Diagnoses that the galvanic cell type oxygen sensor 100 is operating normally, and displays the diagnosis with an LED or the like.

However, the galvanic cell type oxygen sensor 10
When 0 is deteriorated due to, for example, long-term use, the sensitivity is reduced. The characteristic curve (actually, characteristic line) of the input / output characteristic diagram in FIG.
The output voltage (vertical axis) corresponding to (horizontal axis) is not generated.
That is, the output voltage of the second voltage comparator 302 is a reference voltage (S · V) corresponding to the output voltage of the galvanic cell type oxygen sensor 100 corresponding to 98% of SF ₆ gas concentration and 2% of oxygen concentration.
H), when it is input to the inverting input- of the second voltage comparator 302, the H level output voltage is used as a self-diagnosis signal for sensor deterioration as shown in FIG. The data is output to the self-diagnosis display device 13 via the display 11. Then, the self-diagnosis display device 13 diagnoses that the galvanic cell type oxygen sensor 100 is not operating normally and is abnormal. Then, the self-diagnosis display device 13
Turns off the LED and the like. Note that the self-diagnosis display device 13 does not need to be operated at all times, and need only be periodically performed in a short time.

As described above, the galvanic cell type oxygen sensor 1
Since the gas leak is detected by utilizing the characteristic of No. 00, even if abrupt mixing of air or a small amount of gas leak occurs for a long period of time, the gas concentration in the closed container 1 is, for example, SF ₆ gas 25
%, Oxygen 15%, nitrogen 60%, that is, air 75%, the driving mechanism 9
Is locked and the alarm display device 12 is operated. In addition, the self-diagnosis display device 1
3, the self-diagnosis of whether the function of the galvanic cell type oxygen sensor 100 is normal or not is performed while the above-described gas leak detection is being carried out.

[0027]

As described above, according to the present invention, the self-diagnosis output means for diagnosing the degree of deterioration of the oxygen sensor itself is provided to the alarm output means for issuing an alarm according to the output value of the sensor provided in the closed container. With this addition, short-term sudden gas changes can be detected, and long-term deterioration of the detection capability of the oxygen sensor can be diagnosed without fail.This improves the reliability of the sulfur hexafluoride gas-enclosed load switch with gas monitoring device. The effect of increasing was obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an alarm output unit and a self-diagnosis output unit of FIG.

FIG. 3 is an input / output characteristic diagram of a galvanic cell type oxygen sensor.

FIG. 4 is an output characteristic diagram of an alarm output unit and a self-diagnosis output unit.

FIG. 5 is a schematic diagram of the operation of the present apparatus.

FIG. 6 is a configuration explanatory view of a conventional SF ₆ gas-filled load switch with a gas monitoring device.

FIG. 7 is a sectional view of the gas monitoring device of FIG. 6;

FIG. 8 is a schematic diagram showing an operation when an abnormality of the gas monitoring device is detected.

[Explanation of symbols]

1 closed container, 2 movable contacts, 3 movable terminals, 4
Bushing, 5 fixed contact, 6 fixed terminal, 7 bushing, 8 drive shaft, 9 drive lever, 10 lock mechanism device, 11 gas leak monitoring device, 12 alarm display device, 13 self-diagnosis display device, 100 galvanic cell type oxygen Sensor, 200 alarm output means, 300 self-diagnosis output means.

Claims (1)

(57) [Claims] 1. A sealed container having a switch and filled with sulfur hexafluoride gas is provided, and the concentration of oxygen as an impurity gas in the sealed container is detected, and a voltage proportional to the oxygen concentration is detected. a galvanic cell type oxygen sensor which outputs an output value from the galvanic cell type oxygen sensor, in the case of more than a first reference value corresponding to the oxygen concentration of minimum conditions that can ensure the closing function of the switch is Alarm output means for outputting an alarm signal; and an output value from the galvanic cell type oxygen sensor ,
From the second reference value corresponding to the oxygen concentration during normal use of the switchgear
The galvanic cell type oxygen sensor
A sulfur hexafluoride gas-filled load switch with a gas monitoring device, comprising: self-diagnosis means for diagnosing abnormality .