JPH0862082A - Inspection device for pressure sensor - Google Patents

Abstract

PURPOSE: To provide an inspection device for more positively and accurately detecting the failure in a pressure sensor. CONSTITUTION: The gas pressure of a gas insulation electric equipment 1 is measured by a pressure sensor 4 and temperature is measured by a temperature sensor 7. A timer means 9 inputs the measurement values of the pressure sensor and the temperature sensor at 5:00 and 13:00 to a storage means 10. A calculation means 11 calculates the abnormal judgment value of the gas pressure and temperature at 13:00 from the gas pressure at 5:00 and the temperature at 13:00. A judgment means 12 compares an abnormal judgment value with the gas pressure at 13:00 to judge to see if the pressure sensor fails, thus accurately detecting failure by utilizing the change in the increase of gas pressure corresponding to temperature increase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION There is a pressure sensor used for monitoring gas pressure of gas-insulated electric equipment. The present invention relates to an inspection device for inspecting whether or not this pressure sensor is operating normally. Examples of the gas-insulated electrical equipment to which the pressure sensor targeted by the present invention is applied include:
There are a gas-insulated switchgear (hereinafter referred to as "GIS") of a power receiving and transforming facility, a gas circuit breaker, and the like.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional GIS gas pressure monitoring device. The gas pressure in the GIS 1 is the pipe 2 and the valve 3
Through the pressure sensor 4. The pressure sensor 4 is
The gas pressure is converted into an electric signal, and the electric signal is output to the gas pressure monitoring device 5. The gas pressure monitoring device 5 monitors the gas pressure of the GIS 1 based on this signal. Further, the gas pressure monitoring device 5 also monitors from the output of the pressure sensor 4 whether the pressure sensor 4 is operating normally. In addition,
6 is a compound meter.

FIG. 6 is a graph showing an example of the output of the pressure sensor 4. The horizontal axis of the graph in the figure represents time, and the vertical axis represents pressure. In Figure, P represents the output of the pressure sensor 4, Prior to the time t ₁ the pressure sensor 4 is not normal operation, at time t ₁ that an abnormality has occurred the output P to the pressure sensor 4 is lowered It represents.

Pressure sensor 4 and GIS ₁ before time t ₁
When there is no abnormality, the output P of the pressure sensor 4 changes within a range of a predetermined upper limit value P _H and lower limit value P _L. When the output P of the pressure sensor 4 exceeds the upper limit value P _H and the lower limit value P _L , the gas pressure monitoring device 5 determines that an abnormality has occurred in the GIS 1. Also within the scope of the upper limit value MAX and lower limit value MIN of the measurement range of the pressure sensor 4, and the upper limit value P _H
And the lower limit value P _L are exceeded, the upper limit value P _aH and the lower limit value P _{aL of the} abnormality determination value used for the abnormality determination of the pressure sensor 4 are set. At time t ₁ , if an abnormality occurs in the pressure sensor 4 and, for example, its output P abnormally decreases and becomes lower than the lower limit value P _aL , the gas pressure monitoring device 5 determines that the pressure sensor 4 has an abnormality.

[0005]

In the conventional method of inspecting the pressure sensor, the value for judging the abnormality of the pressure sensor is a constant value. Therefore, even if an abnormality occurs in the pressure sensor, if the output does not exceed the upper limit value or the lower limit value of the determination value, for example, the output of the pressure sensor is fixed without fluctuation, or, It was not possible to detect abnormalities that would change randomly regardless of the actual gas pressure.

[0006] It is an object of the present invention to provide an inspection device which can detect an abnormality of a pressure sensor more reliably and accurately.

[0007]

In order to achieve the above object, the present invention provides a pressure sensor for measuring a gas pressure, a temperature sensor for measuring an air temperature, and a storage means for storing a measured value of the pressure sensor and the temperature sensor. , Predetermined first time and second
Of the measured values of the pressure sensor and the temperature sensor stored in the storage means, and the measured values of the pressure sensor and the temperature sensor at the first time among the measured values stored in the storage means. Calculation means for calculating an abnormality determination value of the gas pressure at the second timing using the measurement value of the temperature sensor at the second timing, the abnormality determination value calculated by the calculation means, and the pressure sensor at the second timing. The inspection device for the pressure sensor is configured by the determination means for determining the abnormality of the pressure sensor by comparing the measured value with

[0008]

The first time and the second time in the timer means are, for example, 5 o'clock (5 am) when the temperature is low in one day.
In addition, 13:00 (1:00 pm), which is the highest temperature in the day, is set. The calculation means calculates an abnormality determination value for the gas pressure at 13:00 using a predetermined calculation formula from the gas pressure and the air temperature at 5 o'clock and the air temperature at 13:00 stored in the storage means. Then, the determination means compares the gas pressure measured at 13:00 with the abnormality determination value to determine whether there is an abnormality in the pressure sensor.

As described above, since the abnormality of the pressure sensor can be inspected by utilizing the change in the rise of the gas pressure corresponding to the rise of the temperature, the abnormality of the pressure sensor can be detected with higher accuracy. Further, by selecting a time with a large temperature difference in one day such as 5:00 and 13:00, the accuracy can be further improved.

[0010]

FIG. 1 is a block diagram of an embodiment of a pressure sensor inspection device of the present invention. The circuit for monitoring the gas pressure of GIS by the pressure sensor is not shown. In the figure, 4 is a pressure sensor for measuring the gas pressure of the GIS 1, and 7 is a temperature sensor for measuring the temperature of the place where the GIS 1 is installed. The measured values of these sensors 4 and 7 are output to the timer means 9.

The timer means 9 has a predetermined first time and a second time.
At this time, the input measured values of the sensors 4 and 7 are output to the storage means 10 and stored therein. In this embodiment, the first
The time of 5 is set to 5 o'clock, and the second time is set to 13 o'clock. Reference numeral 11 denotes a calculation means, which calculates an abnormality determination value of GIS1 at 13:00 from the measured value stored in the storage means 10 and outputs it to the determination means 12. The determination means 12 is the storage means 10.
The measured value of the pressure sensor 4 stored at 13:00 is compared with the abnormality determination value value calculated by the calculation means 11 to determine whether the pressure sensor 4 is abnormal.

Next, the operating principle of the pressure sensor inspection device having the above-described structure will be described. In FIG. 2, the gas pressure P of the GIS 1 measured by the pressure sensor 4 on a certain day,
The change in the temperature T measured by the temperature sensor 7 is shown. As is clear from the figure, normally the temperature is the lowest at 5 o'clock a day and the highest at 13:00. If the gas pressure P changes only due to the temperature, the peak should be at 13:00, but actually it changes due to other factors.
Therefore, in the illustrated example, the peaks of the gas pressure P and the temperature T are deviated.

That is, the gas pressure P of GIS1 is
It also changes due to load current application and solar radiation when outdoors. Now, it is assumed that the gas pressure increase due to the temperature factor in the normal operation state of GIS1 is ΔP _a , the gas pressure increase due to load current conduction is ΔP _IU , the decrease is ΔP _ID, and the gas pressure increase due to solar radiation is ΔP _S. Further, the temperature at 5 o'clock is T ₅ , the gas pressure at 5 o'clock is P ₅ , the gas pressure at _13:00 is P ₁₃ , and the air temperature at _13:00 is T ₁₃ .

Where ΔP_IU, ΔP_ID, ΔP_SThat's it
This is one that is expected to change during normal operation of GIS1.
Set to a fixed value. Then, the gas pressure P at 13:00₁₃Is a figure
As shown in 3, the gas pressure P at 5 o'clock_FiveAgainst the temperature
Rise (T₁₃-T_Five) As a factor_aTo rise. It
Gas pressure P₁₃P depends on other factors_Five+ ΔP
_aHigher or lower, but its maximum value P_aHIs P_Five+
ΔP_aTo ΔP_IUAnd ΔP _SThe minimum value
P_aLIs P_Five+ ΔP_aTo ΔP_IDIs the value obtained by subtracting.

That is, when the temperature changes from T ₅ to T ₁₃ , and there is no abnormality in the pressure sensor 4, the gas pressure P _{13 of} GIS1 should fall within the range of P _aH and P _aL . Therefore, by using P _aH and P _aL as abnormality determination values, it is possible to determine that the pressure sensor 4 is abnormal if the gas pressure at 13:00 is outside this range. Next, the operation of this embodiment will be described in detail with reference to the flowchart of FIG.

At 5 o'clock (Y in step S1), the timer means 9 stores the temperature T ₅ measured by the temperature sensor 7 and the gas pressure P _{5 of} GIS1 measured by the pressure sensor 4 in the storage means 1.
It is output to 0 and stored (step S2). When the timer means 9 reaches 13:00 (Y in step S3),
The temperature T ₁₃ measured by the temperature sensor 7 and the gas pressure P _{13 of} GIS1 measured by the pressure sensor 4 are output to the storage means 10 and stored therein (step S4).

Next, the calculation means 11 determines the abnormality determination value P _aH ,
P _aL is calculated using the following formula (step S5). P _aH = P ₅ + L (T ₁₃ −T ₅ ) + ΔP _IU + ΔP _S P _aL = P ₅ + L (T ₁₃ −T ₅ ) −ΔP _ID Here, L (T ₁₃ −T ₅ ) is ΔP _a . L is a gas density constant, and a different value is set depending on the gas pressure and the like. Further, ΔP _IU , ΔP _ID , and ΔP _S are constants set as described above.

The determination means 12 compares the gas pressure P ₁₃ stored at 13:00 in the storage means 10 with the abnormality determination values P _aH and P _aL calculated by the calculation means 11 (step S6). If there is a relation of P _aH > P ₁₃ > P _aL (step S6
Y) of the pressure sensor 4 is determined to be normal (step S
7) Return to step S1. If the pressure is out of the range (N in step S6), it is determined that the pressure sensor 4 is abnormal (step S8), an alarm or the like is output, and the inspection operation is ended.

According to the pressure sensor inspection device described above, the abnormality inspection of the pressure sensor 4 can be performed by utilizing the change in the rise of the gas pressure corresponding to the rise of the air temperature.
It is possible to detect abnormalities in the pressure sensor with high accuracy. For example, in the case of an abnormality in which the output of the pressure sensor is fixed without fluctuating,
Due to the change in air temperature between 5:00 and 13:00, the abnormality determination value becomes higher than the gas pressure at 5:00, but the output of the pressure sensor does not become high at 13:00. Therefore, 13
The abnormality can be detected by comparing the output of the pressure sensor at that time with the abnormality determination value.

This is also the case when the output of the pressure sensor changes randomly regardless of the actual gas pressure.
In this case, at the time of measurement at 13:00, a random change may happen to fall within the abnormality determination value, and the abnormality of the pressure sensor may not be detected at that time. However, even in such a case, there is a high probability that a random change will exceed the abnormality determination value at the time of inspection on and after the next day, so that the abnormality of the pressure sensor will be detected.

Further, since the abnormality judgment value can be decided based on the gas pressure at the time when the temperature difference is large in one day, the judgment accuracy can be made constant throughout the year.

[0022]

According to the present invention, the abnormality of the pressure sensor
It is possible to obtain an inspection device that can detect more reliably and accurately.

[Brief description of drawings]

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

FIG. 2 is a graph showing changes in gas pressure and temperature of the GIS of FIG.

FIG. 3 is a diagram for explaining the operating principle of the inspection device of FIG.

FIG. 4 is a flowchart for explaining the operation of the inspection device in FIG.

FIG. 5 is a view showing a conventional gas pressure monitoring device.

6 is a graph showing the operating principle of the gas pressure monitoring device of FIG.

[Explanation of symbols]

 1 ... GIS 2 ... Piping 3 ... Valve 4 ... Pressure Sensor 5 ... Gas Pressure Monitoring Device 6 ... Compound Meter 7 ... Temperature Sensor 9 ... Timer Means 10 ... Storage Means 11 ... Calculation Means 12 ... Judgment Means

Claims (1)

[Claims] 1. A pressure sensor for measuring a gas pressure, a temperature sensor for measuring an air temperature, a storage means for storing the pressure sensor and a measured value of the temperature sensor, and a predetermined first time and a second time. Timer means for storing the measured values of the pressure sensor and the temperature sensor in the storage means, among the measured values stored in the storage means, the measured value of the pressure sensor and the temperature sensor at the first time Calculation means for calculating an abnormality determination value of the gas pressure at the second timing using the measurement value and the measurement value of the temperature sensor at the second time, and the abnormality determination value calculated by the calculation means and the first An inspection device for a pressure sensor, comprising: a determination means for determining an abnormality of the pressure sensor by comparing the measured value of the pressure sensor at the time 2).