JPH03222613A - Gas leakage-monitoring device of gas-insulated electric equipment - Google Patents

Abstract

PURPOSE:To correctly monitor a gas leakage through automatic measurement by providing a gas pressure sensor, an outside air temperature sensor, a density operating means for computing the rate of change of gas pressure to gas temperature and the gas pressure at 0 deg.C, a natural leakage-monitoring means, a gas pressure reference value-computing means and an emergency leakage-monitoring means. CONSTITUTION:Each gas section of a GIS(gas-insulated switchgear) 2 is provided with pressure sensors 1a, 1b,...1n and with an outside air temperature sensor 3 and also with a microcomputer-monitoring part 4, an input amplifier 5, a multiplexer 6, an A/D converter 7 and a data memory part 8, and a means for periodically computing gas density data is formed by a first operating part 9. the natural leakage monitoring means 11 stores and holds a gas pressure and an emergency leakage determination part 12 performs computing a gas pressure to be used as a criterion for determination per unit time and also comparing and determining a detected pressure and the gas pressure.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention is applicable to each gas insulating system (CIS), etc. [Prior Art] Conventionally, in GIS, the main circuit section is housed in a metal container for each unit such as a unit of equipment. It is divided into gas compartments, and the gas compartments are filled and sealed with sulfur hexafluoride (SF6) gas (hereinafter referred to as insulating gas) as an insulating medium. The pressure of this gas (gas pressure) decreases due to gradual natural leakage due to long-term use and relatively rapid gas leakage (emergency leakage) due to sudden airtight abnormality. By the way, if the gas density within the compartment is constant, the gas pressure P varies linearly with the gas temperature T, as shown in FIG. In this Fig. 6, PmaX, P, P= are the initial filling gas pressure (rated gas pressure), the general gas pressure used, and the characteristics of the minimum gas pressure used (gas leakage caution pressure).
P2 Gma rate (gas density coefficient) L,
The gas pressure M at the gas temperature T-0°C is expressed as the pressure Pma
Let the straight line of X be l$aX, Mm aX, and the straight line of pressure Pm be, Phr=(Lma
”), then the following formula [1]. Expression [2 Toju. Pmax = Lmax T+%Jmax
・Formula [l] Pmln=Lmin ・T+Mmin
Formula [2] And the above LmaX *M
The specific sizes of the ffiaX and L layers and Mm are the rated gas pressure P2omax at the reference temperature C-20°C,
Gas leak caution pressure p20m is P2 Qma) (,:4C
K4fyd・g), Pzo Moe-3,6CKgfyc#g
In the case of section 1301 of ], the result is as shown in Table 1 below. Table 1 Also, Pzo,, 1aX= 5 (Kyf yc# g
), Pzo== 4.7CKgf lcrdg]
In the case of the section 200e, the result is as shown in Table 2 below. Conventional GISO gas leak monitoring requires a gas pressure gauge (
Measurement of workers using a compound air meter) and an outside air meter. Based on judgment, this is mainly done to target natural leakage. Table 2 That is, as a periodic measurement, for example, the scales of the gas pressure gauge and the outside temperature gauge are read at a fixed time during the employee's working hours (usually during the day). Then, using the outside air temperature as the gas temperature, the gas pressure is converted into a pressure at 20° C. using the characteristic graph shown in FIG. Further, the converted gas pressure is recorded, and a gas leak is detected from the gas pressure change trend (leak trend) of this record. [Problems to be Solved by the Invention] In the case of the conventional manual gas leak monitoring, the measurement interval is relatively long, such as one day, so the discovery of sudden emergency leaks is delayed and sufficient monitoring cannot be performed. There are some problems. On the other hand, while the GIS is in operation, the main circuit section generates heat due to the load current of the system using this GIS, and the gas temperature changes, and this change changes the gas pressure. Furthermore, in the case of a GISO installed outdoors, the container temperature of the gas compartment changes due to the influence of outside air including weather conditions such as solar radiant heat in the installation environment, and the gas pressure also changes due to the change in gas temperature that follows this change. Even if the surface temperature of the bottom of the container, which is shaded to avoid the influence of direct sunlight, is measured as the outside air temperature, the daily change between this outside air temperature and the actual gas temperature (average temperature inside the container) is, for example, As shown in Figure 7, there is a large difference in temperature between September and November, and the difference in temperature during the daytime is especially significant. In this Figure 7, the solid line based on the * mark and the dashed line based on the X mark indicate the outside air temperature and gas temperature in September. show. Therefore, if measurements are taken during the daytime based on changes in system load, the influence of outside air, etc., gas temperature measurements will be extremely inaccurate. Furthermore, there is a problem in that gas pressure can only be measured very roughly due to inaccurate measurement of gas temperature, reading error of scale, etc., and even gradual natural leakage cannot be accurately monitored. Moreover, it requires complicated work such as reading the scale, and there is also the problem that monitoring cannot be simplified. SUMMARY OF THE INVENTION An object of the present invention is to provide a gas leak monitoring device for gas-insulated electrical equipment that accurately monitors both natural leaks and emergency leaks through automatic measurement. [Means for Solving the Problems] In order to achieve the above object, the first configuration of the gas leak monitoring device of the present invention includes a gas pressure sensor that detects the gas pressure in the gas compartment, and a gas pressure sensor that detects the outside air temperature. The gas temperature is calculated by an interpolation method or the like based on the detected pressure Pa of the gas pressure sensor during the early morning hours as the gas temperature detected by the temperature sensor during the early morning hours when electricity is regularly energized and the influence of outside air is small. Rate of change of gas pressure La
and a density calculation means for calculating and determining the gas pressure NIa at 0°C as gas density data, and Pc(a)2LaC0Ma based on the gas density data
a natural leakage monitoring means for accumulating and holding gas pressure Pc(a) for natural leakage monitoring converted to a reference temperature C using a conversion formula; a temperature Tn detected by the temperature sensor for each unit time such as one minute;
a reference value calculating means for calculating a gas pressure PN for the judgment standard for each unit time according to the judgment calculation formula PN=LaTn+Ma−K (7) based on the gas density data and the judgment threshold K (K>0); An emergency operation in which the detected pressure Pn of the gas pressure sensor for each unit time is compared with the gas pressure PN, and when the detected pressure Pn falls below the gas pressure PN for a predetermined number of consecutive times, it is determined that there is a sudden emergency leak. Fully equipped with leak monitoring means. Further, in the second configuration of the present invention, a gas pressure sensor that detects the gas pressure in the gas compartment, a temperature sensor that detects the entire outside temperature, and both of the above-mentioned sensors are periodically energized and set in the early morning when the influence of the outside air is small. Based on the detected pressure Pa of the sensor, the detected temperature Ta, and the set value LO of the rate of change of gas pressure with respect to the gas temperature, the detected temperature Tag is the gas temperature Pc (a) = L0 · (C - Ta)
A natural leak monitoring means for accumulating and holding gas pressure Pc(a)i for natural leak monitoring converted into the detected pressure Pa and reference temperature C by a conversion formula of +Pa, and the detected pressure of both sensors for each unit time such as 1 minute. Pn, Pc(n)=based on the detected temperature Tn and the set value LO
=L0...(C-Tn) Determined from the constant conversion means for converting the detected pressure Pn into the gas pressure Pc(n) at the reference temperature C from the conversion formula of ten Pn and the latest gas pressure Pc(a). The gas pressure Pc(n) is compared with the gas pressure Pcr as the gas pressure pcr for the threshold K(K>0) low gas pressure total judgment criterion, and the gas pressure Pc(n) is continuously maintained a predetermined number of times. and emergency leak monitoring means for determining a sudden emergency leak when the gas pressure falls below the gas pressure Pcr. [Operation] In the case of the first configuration, the monitoring device of the present invention configured as described above, at the early morning scheduled time 9, for example, 5 a.m. (a-5),
There is little system load, etc., and gas temperature changes due to energization in the compartment are extremely small. Data (Ls, Ms) of characteristic lines corresponding to the characteristic lines PmaX g P and Pxtim shown in FIG. 6 are accurately determined by the calculation means from the true gas pressure in the compartment. Furthermore, the data (Ma, La) is updated at intervals of about one day in accordance with gas leakage due to the periodic calculation decisions of the density calculation means. Then, each time the data (Ls. Ms) is updated by the natural leakage monitoring means, the gas pressure P2 converted to the reference temperature C9, for example, 20°C, is determined from the characteristic line based on the data.
At this time, the gas pressure P20 (5) changes accurately according to the degree of gas leakage without being affected by electricity or outside air, so the natural leakage monitoring means is Accurate measurement results of gas pressure are periodically accumulated and held, and natural leakage can be monitored with high precision from the change trend of gas pressure based on the held results.In addition, the standard value calculation means is used to monitor data (Ls, Ms) based on the data (Ls, Ms). The gas pressure PN of a characteristic straight line that is shifted to a lower pressure by a threshold value than the characteristic straight line when there is no gas leak is calculated while being updated at short time intervals according to the outside air temperature Tn at that time. By comparing the monitoring means, the outside air temperature Tn is set as the total gas temperature, and by utilizing the fact that if there is no gas leakage, the detected pressure Pn is higher than the gas pressure PN by at least a threshold value, the judgment criterion is varied according to the outside air temperature Tn. However, a decrease in gas pressure is constantly detected at the short time interval, and emergency leakage is monitored.
Since the emergency leak monitoring means determines that there is an emergency leak when the leakage value decreases below N and an emergency leak is reliably detected, the emergency leak can also be monitored quickly and with high precision by automatic measurement. In addition, in the case of the second configuration, the gas density coefficient is preset to LO, and by conversion using this coefficient = L0 · i, the natural leakage monitoring means is set at It is converted into gas pressure P20(5) in °C and stored and held. This gas pressure P20(5) is a gas pressure that excludes the influence of electricity and outside air, and the result of holding the gas pressure P20(5) enables highly accurate monitoring of natural leakage similar to the natural leakage monitoring means of the first configuration. I can do it. Further, the constant conversion means uses the coefficient LO to calculate the detected pressure Pn at each short time interval by, for example, 20°CO gas pressure P2.
ward n). Then, the gas pressure P20 (5) is determined by the emergency leakage monitoring means.
Based on the comparison between the gas pressure P+or, which is low only at the threshold value, and the gas pressure P2o(n), a decrease in the gas pressure is constantly detected in terms of 20°C, and the gas pressure P2o(n)
It is determined that there is an emergency leak when the gas pressure decreases below the gas pressure P2or for a predetermined number of consecutive times. Therefore, based on the gas density coefficient LO, the criterion is fixed and the emergency leakage is quickly and accurately monitored by converting the gas pressure Pn f to 20°C. [Example] An example applied to GIS will be described with reference to FIGS. 1 to 5. (1 Example) First, regarding the example of calculating gas density data, the gas pressure sensor (3) is a temperature sensor outside G I 5 (2), and the bus line is adjusted so that it is as equal to the gas temperature as possible. P.T.
It is installed in a shaded area on the outer surface of the metal container in the gas compartment where it is less affected by energization. (4) is a microcomputer-configured monitoring section, (5) is an input amplifier for the monitoring section (3), (6) is a multiplexer,
(7) forms an A/D converter, and (8) forms a gas density calculation means for accumulating measurement data of pressure and temperature. +101 is the second calculation unit, and in this example,
Constantly calculates gas pressure based on gas density data. (11) is a trend memory section as a natural leak monitoring means, gas pressure Pc (a cold storage function is increased). (I2) is a reference value calculation means, and an emergency leak judgment forming a means for monitoring emergency leaks.・）3) is the judgment part (an event that holds the judgment results of 1 The memory section (14) is a local emergency leak alarm section,
Notifies the occurrence of an emergency leak by displaying a lamp, outputting a buzzing sound, etc. (15) is the calculation unit 19! e This is an arithmetic control unit that performs condition setting of lOi, output control, etc. Then, a gas pressure sensor (
The analog output of la) (In) and the analog output of the temperature sensor (3) proportional to the outside temperature are supplied in parallel to the multiplexer (6) via the input amplifier 5), and by switching the output of this multiplexer (6), each analog The outputs are sequentially and repeatedly supplied to the A/D converter (7). At this time, the output switching cycle of the multiplexer (6) is set to, for example, 1 minute, taking into consideration the accuracy of emergency leakage detection, etc.
Gas pressure and outside temperature in each compartment are measured every minute. Furthermore, the A/D 'fJ converter (7) is a multiplexer (
The output of step 6) is sampled and converted into digital data to form data on the detected pressure of each section and the detected temperature of the outside air, and the data is supplied to the data memory section (8). This memory section (8) accumulates and holds data on the detected pressure and outside temperature of each section. Then, based on the data in the data memory section (8), the calculation section ""e flo+ calculates the gas density data of each section,
Perform gas pressure conversion. Next, gas density data calculation by the calculation section (9) will be explained. In each section, if the gas pressure is k PT [Kgf /c++L g ] when the gas temperature is T'C, then
The characteristic line of gas pressure with respect to gas temperature is expressed by the above formula [
1]9 Similar to equation [2], it is expressed by the following equation [3]. PT2LT-T+MT ・
Equation [3] And the gas density coefficient LT and gas pressure MT in Equation [3] are calculated as follows based on Equation [1] 2 Equation [2] and the conditions shown in Table 19 and Table 2 above according to the capacity of the compartment. Formula [4a)
, if the gas temperature is accurate, it can be determined with almost no error, although it is approximate. LT = (LmaX −Lmi+) −(p'r −
P max) / (P max - P expansion) + Lmax formula [
4a] ~IT=(~1max-M+=) (pT-Pmax
)/(Pmax-P,,,) +Mmax formula [4b] As is clear from Figure 7, at 5 a.m., the influence of the energization and outside air is extremely small, and the outside air temperature and gas temperature are almost equal. That is, the gas pressure sensor (la,) (in
), and the detected temperature 2 Ta of the temperature sensor (31) at this time is Ts, then T5 becomes the gas temperature, and P5 becomes the gas pressure excluding the influence of energization etc. on this temperature T5. Therefore, the calculation unit (9) periodically, that is, every day, executes all the calculations of equations [4a] and [4b] as PT=Ps, LT=L5, and MT s based on the detected pressure P5, and the gas temperature reaches T5. Assuming that the gas pressure becomes P5 at some time, the gas density coefficient L5, the gas pressure Msi at 0°C, is calculated and determined for each section as the gas density data for that day.This calculated and determined gas density data is
, is supplied to the trend memory section (11), etc. The trend memory section (11) calculates the gas pressure at 5 o'clock every year based on the gas density by converting it into the following equation [5] based on the gas density data. P 2 G (5) (蒐P c(a)
) and accumulate and hold it. P2O(5):L5・20+Ms formula [
5] This gas pressure P20(5) decreases due to gas leakage, and from its decreasing tendency, the state of natural leakage can be ascertained by applying electricity and excluding the influence of outside air. Therefore, based on the accumulated results of the trend memory section (11), measurements for natural leakage, which were conventionally performed manually, can be performed.
Recording is done automatically and accurately. Then, based on the accumulated results of the trend memory section (11), natural leakage is detected and monitored by automatic or manual discrimination of the downward trend in this memory section (river or arithmetic control section (15), etc.). , gas pressure conversion by the calculation unit (10) will be explained.
If there is no gas leak for a day and the gas density does not change, and the detected temperature Tni gas temperature at time n (n-..., n-1, n,...) is the following based on the gas density data: Gas pressure (hereinafter referred to as converted pressure) Pn' in formula [6]
and the detected pressure Pn at that time n are equal. Pa=Ls−Tn+MS” formula [
6] This gas pressure pn't is shown by the characteristic line P in FIGS. 2 and 3. Then, the calculation unit (lO) calculates the detected temperature 'r for a unit time 2, for example, every minute, which is set based on the emergency leakage detection speed, etc.
Based on n, the converted pressure Pn' per minute is calculated from equation [6] for each section. Then, the detected pressure Pn and the converted pressure pn are determined by the determination unit (12).
The determination unit (12) determines whether there is an emergency leak in each section at one-minute intervals. Next, the determination processing of the determination unit (12) will be explained. For example, in a gas compartment with a capacity of 1301, the standard 10-1 [CC/g!] based on an emergency leak! When the gas leak c) occurs, the amount of decrease in gas pressure for one day based on this leak is expressed by the following equation [7]. Due to the leakage of this formula [7], the rated gas pressure P20maX
A simple calculation shows that the time required for the gas leak warning pressure to drop from P20m++x to (4-3, 6)10.
1 = 4 days. Therefore, a gas leak cannot be detected until four days have passed using only the periodic accumulation results for a relatively long period of time in the trend memory section (9). The reference value is compared with the detected pressure Pn at every time n, and an emergency leak is detected at 1 minute intervals. At this time, the outside temperature changes, for example, as shown by the solid line t in Figure 3, and the influence of energization and outside air changes. Since the gas temperature changes and the gas pressure changes to follow this change, it is necessary to change the judgment reference value according to this change.Then, the detected temperature at every time n is regarded as the gas temperature. Therefore, if there is no gas leak, the gas pressure P at every time n
n becomes larger than the converted pressure Pn' of equation [6]. Therefore, in the case of section 1301, the determination unit (12)
The determination threshold value Ki is set to a practical value of 01, and is calculated and set as the gas pressure 01 lower than the converted pressure Pn', that is, the gas pressure for the determination criterion at every time n of the gas pressure PNi of the following equation [8]. PN=Ls-Tn-1-Ms-Q,l
・Formula [8] Furthermore, the determination unit (12) compares the detected pressure Pn and the gas pressure PN at every time n, and detects that the detected pressure Pn is lower than the gas pressure PN twice in a row, and gas leakage is definitely detected. When detected, for example at time n in FIG. 3, it is determined that there is an emergency leak and an emergency leak alarm is generated. By the way, the difference ΔTn [deg] (=Tn') between the detected temperature Tn (outside air temperature) at every time n and the actual gas temperature Tn'
-Tn), gas pressure PN at the time of judgment and 5 am
The amount of decrease in the determination reference value from the gas pressure P 20 (5) at the time is as shown in Table 3 in the range of Tn, 8 Tn, which actually occurs in the section 1301. In this Table 3, P2ON indicates the gas pressure PN converted to 20°C, and P2 o (s) - P2 oN indicates the amount of decrease. Further, based on the difference □QTn, the gas pressure P2ON becomes as shown in FIG. 2 with respect to the gas pressure P2G(5). As is clear from Table 3, the detection sensitivity decreases as the difference ΔTn increases; however, in an actual gas leak, the rate of decrease in gas pressure decreases over time, so the determination unit; The gas pressure is the maximum usable gas pressure (13
3 for 01. An emergency leak is detected with a considerable margin of time before the pressure drops to O[Kg/cfIgl). Table 3 Furthermore, the emergency leak alarm of 12 in the judgment part is stored in the event memory part, +3. , is supplied to external devices of the notification section (14) and the monitoring section (4), and is notified of the occurrence of an emergency leak. Therefore, it is possible to detect emergency leaks, which was not possible in the past. Monitoring can be performed automatically, accurately and quickly, and emergency leaks can be detected at a relatively early stage. Calculation conditions for gas density data, threshold values, etc. may be set according to the capacity of each section. (Other Examples) Next, an example in which the gas density coefficient is set in advance will be described with reference to FIGS. 1, 4, and 5. The difference between the device of this embodiment and the device of the first embodiment is that
The calculation section (9) in the figure is the gas pressure conversion section at 5 am every morning,
The calculating section f9+, l-lend memory section (11j) forms a natural leak monitoring means, and the calculating section (10) forms a constant conversion means.The calculating section (9) calculates the gas density data. Instead of performing Lma of Table 12 and Table 2 according to the capacity of each section,
The arithmetic mean value of X and Lm++ is set in advance as L0·i gas density coefficient. (15) is set in the calculation unit fil, jlo). Then, the calculation part (9) is the detected pressure Ps at 5 o'clock every year. Based on the detected temperature T5 and LO, the following formula is calculated.

From [9], the detected pressure P5 is converted into a pressure P20(5) where C=20@C, for example. P2O(S)=Ps10.0023・(20-T5)
formula

[9] This pressure P20 (5) is the detected temperature T
Since 5 is almost equal to the gas temperature, it is a converted value of gas pressure excluding the influence of electricity and outside air. Then, the gas pressure P20 (5) is determined by the trend memory section (I
I), and based on the retention results, natural leak detection and monitoring are performed in the same way as in the I embodiment. In addition, the calculation unit (10j calculates the detected pressure Pn by the following equation [10] based on the detected pressure Pn, detected temperature Tn, and LO at each time n) as the gas pressure P 20 (n) at C-20°C.
Convert to . P2 o(n)=P n0CD': OI3-・(20
-Tn) Equation [10] Then, the gas pressure P20(5) and the gas pressure Pzo(n) are determined by the determination unit (I2
). At this time, the determination unit <+2H is different from the case of the first embodiment,
The gas pressure P20(5)- is set as the gas pressure P2or (2 Pcr) for the judgment standard, and this gas pressure Pzo
Compare r with the gas pressure P 20 (n) at every time n. In addition, in the 2001 gas compartment, the standard gas leakage amount based on emergency leakage is 3 x l0-1 [CC/seC]
The amount of decrease in gas pressure over one day due to this leakage is expressed by the following equation [11]. 3xlO-'x60X6°"4≦Q, 15 CKqf
ictii:] -Formula l:11)%Formula% Therefore, the threshold value is set to 0.15. Also, based on the difference ΔTn between the detected temperature Tn (outside air temperature) at each time Tn and the actual gas temperature Tn', the gas pressure P20
For (5), the gas pressure P 20 (n) is as shown in FIG. Then, the determination unit 12) determines that there is an emergency leak and issues an emergency leak alarm at time n in FIG. 5 when the gas pressure P20 (b) falls below the gas pressure pcr twice in a row. In FIG. 5, the solid line [ represents the detected temperature Tn (outside air temperature), and the solid line p represents the detected pressure Pn. In addition, Tn ATn actually generated in the gas compartment of 200E
(range) Here, the amount of reduction based on conversion of gas pressure when an emergency leak is determined and the true amount of reduction are shown in Table 4 below. Table 4 In addition, in Table 4, Pzo(n) rice, (P2O(5)-
Pzo(n)) indicates the true gas pressure and the amount of decrease in 20°C. However, the usage limit gas pressure of 200e is 4. OCKgf/
An emergency leak is detected with a considerable margin of time before the temperature drops to cd ·g). Natural leaks and emergency leaks can be detected with a simpler calculation configuration.
be monitored. The set value LO, threshold value, etc. may be set according to the capacity of each section. Further, in both of the above embodiments, the regular early morning time was set at 5:00 a.m. every year, but it may be set every few days instead of every day, or at an appropriate time before or after 5:00 a.m. [Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below. First, in the structure of claim (2), gas density data is periodically calculated and determined by fully utilizing the fact that the outside air temperature during the early morning hours is almost equal to the gas temperature, and based on this gas density data, the outside air temperature during the early morning hours is determined to be approximately equal to the gas temperature. Since the gas pressure was converted to the pressure at the reference temperature and stored and held, this holding result allows for highly accurate monitoring of natural leakage. Furthermore, based on the gas density data, a gas pressure for judgment criteria is calculated according to the detected temperature for each unit time, and an emergency leak is detected by comparing this gas pressure and the detected pressure for each unit time. Allows for quick and accurate monitoring. Therefore, natural leaks and emergency leaks can be monitored with high accuracy based on the gas density data that is calculated and determined on a regular basis. Next, in the configuration of claim (2), the rate of change of the gas pressure with respect to the gas temperature is set in advance, and based on this rate of change, the gas pressure at a fixed time in the early morning is periodically converted to the pressure at the reference temperature and stored and held. Highly accurate monitoring of natural leakage is possible with simple calculations. Furthermore, the detected pressure for each unit time is converted into a gas pressure at a reference temperature based on the rate of change, and this gas pressure is converted for each unit time to a judgment standard gas pressure based on the converted gas pressure at the early morning time. Since emergency leaks are detected by comparing the values, emergency leaks can be monitored quickly and accurately with simple calculations. Therefore, based on the preset rate of change in gas pressure,
Natural leakage and emergency leakage can be monitored with high precision using simpler calculations than when calculating and determining gas density data.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of the gas leak monitoring device of the present invention, Figure 1 is a block diagram, Figure 3 is a gas pressure car temperature characteristic diagram for emergency leak detection in one embodiment. , an operation explanatory diagram, FIGS. 4 and 5 are gas pressure car temperature characteristic diagrams and operation explanatory diagrams for emergency leak detection of other embodiments, and FIGS. 6 and 7 are GI
They are a gas pressure and temperature characteristic diagram of S, and a characteristic diagram of gas pressure and outside air temperature. (1a)-(1n)...Gas pressure sensor, (3)...
・Temperature sensor, 4)・・Monitoring section 1.9:・Written%/U:
Arithmetic unit, (□+01-・-4 consideration arithmetic unit, 11...Trend memory unit 1.12. Emergency leakage determination unit.

Claims (2)

[Claims] (1) A gas pressure sensor that detects the gas pressure in the gas compartment, a temperature sensor that detects the outside air temperature, and the detected temperature T_a of the temperature sensor, which is periodically energized and set in the early morning when there is little influence from the outside air, is taken as the gas temperature. density calculation means for calculating and determining the rate of change L_a of the gas pressure with respect to the gas temperature and the gas pressure M_a at 0° C. as gas density data by calculation using an interpolation method or the like based on the detected pressure P_a of the gas pressure sensor at the early morning fixed time; , P_c_(_a_)=L_ based on the gas density data
a natural leakage monitoring means for accumulating and holding gas pressure P_c_(_a_) for natural leakage monitoring converted to a reference temperature C using a conversion formula of a・C+M_a; a temperature T_n detected by the temperature sensor for each unit time such as one minute; P_N=L_a・T_ based on the gas density data and determination threshold value K (K>0)
a reference value calculation means that calculates a gas pressure P_N for the judgment standard for each unit time using a judgment calculation formula of n+M_a-K; and a detection pressure P_n of the gas pressure sensor for each unit time.
and the gas pressure P_N, and determines a sudden emergency leak when the detected pressure P_n falls below the gas pressure P_N a predetermined number of times in succession. Gas leak monitoring device for insulated electrical equipment. (2) A gas pressure sensor that detects the gas pressure in the gas compartment, a temperature sensor that detects the outside air temperature, and the detected pressure P_a and detected temperature T_a of both sensors, which are regularly energized and set in the early morning when there is little influence from the outside air. Based on the set value L_0 of the rate of change of gas pressure with respect to the gas temperature and the detected temperature T_a as the gas temperature, P_c(a)=L_0・
The detected pressure P is determined by the conversion formula (C-T_a)+P_a.
natural leakage monitoring means for accumulating and holding gas pressure P_c_(_a_) for natural leakage monitoring, which is obtained by converting _a into a reference temperature C; pressures P_n detected by the two sensors for each unit time such as one minute;
P_c_ based on the detected temperature T_n and the set value L_0
From the conversion formula (_n_)=L_0・(C-T_n)+P_n, the detected pressure P_n is converted to the gas pressure P at the reference temperature C.
A constant conversion means for converting into _c_(_n_), and a determination threshold value K based on the latest gas pressure P_c_(a).
(K>0) Gas pressure P_c for judgment criterion low gas pressure
The gas pressure P_c_(_n_) and the gas pressure P_c_r are compared as _r, and the gas pressure P_c_(_
A gas leak monitoring device for gas-insulated electrical equipment, characterized in that the device comprises an emergency leak monitoring means for determining a sudden emergency leak when the gas pressure P_c_r (n_) falls below the gas pressure P_c_r a predetermined number of times in succession.