JPH03253210A - Supervisory device for gas insulation transformer equipment - Google Patents

Abstract

PURPOSE:To contribute to environmental protection by automatically sampling charging gas in an enclosed tank and supplying sampling gas to the enclosed tank of the other gas insulation electrical equipment, whose internal pressure is lower than that of a gas insulation transformer equipment, while generating a data signal which shows concentration of a predetermined component in the sampling gas. CONSTITUTION:Charging gas in an enclosed tank 3 is automatically fetched and sampled by a sampling means 8, and also the concentration of a predetermined component is measured by a measuring means 12 to automatically generate a data signal which shows the concentration of the gas component. Accordingly, whether a gas insulation transformer equipment 1 is placed or not in a warning condition leading to a fault can be judged based on the data signal. While gas, presented for component measurement by the measuring means 12, is supplied into the enclosed tank of the other gas insulation electrical equipment having internal pressure lower than that of the gas insulation transformer equipment 1 which is an inspected object.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) The present invention is directed to monitoring the state of insulating gas in a closed tank in order to improve the reliability of gas-insulated substation equipment. This invention relates to a monitoring device for gas-insulated substation equipment.

(Conventional technology) Generally, when an accident occurs in substation equipment,
There is a risk that the power supply will be stopped unexpectedly, which will have a serious negative impact on the load and its peripheral equipment, and that the substation equipment itself will become irreparable, resulting in a large economic loss. For this reason, conventional methods have been used to prevent accidents in substation equipment by regularly monitoring the status of substation equipment, thereby stabilizing the power supply and requiring only minor repairs to malfunctioning parts. Efforts are being made to reduce economic losses.

When performing such monitoring, it is necessary to monitor for signs of abnormal conditions because the main components of gas-insulated substation equipment such as gas-insulated transformers and gas-insulated switchgear are housed in sealed tanks. Difficult to monitor directly. Therefore, in recent years, it has been discovered that when abnormally overheated parts or corona discharge occur in gas-insulated substation equipment, there is a phenomenon in which the internal insulating gas (for example, 5Fs) undergoes a chemical change and decomposition gas is generated. We focused on the phenomenon that when thin insulating materials such as insulating paper and plastic films deteriorate naturally, co and CO2 are generated due to the decomposition of polymers.
It is being considered to monitor precursory conditions that may lead to an accident based on changes in the composition of gas filled in a sealed tank.

Specifically, a worker collects the required amount of gas filled in gas-insulated substation equipment as a sample into a portable cylinder, and then takes the cylinder to a facility equipped with testing equipment to examine the components of the sample gas, for example. Gas analyzers are used to perform inspections, and based on the test results, it is determined whether there are precursory phenomena that may lead to accidents.

(Issue 8 to be solved by the invention) In the above-mentioned conventional configuration, each time the filling gas in the gas-insulated substation equipment is tested, a troublesome procedure is required to sample gas and test the sample gas with a gas analyzer. Therefore, there is a problem that the labor required for the inspection becomes large. Furthermore, in the past, the gas sampled (that is, the gas whose main component is insulating gas) was released directly into the atmosphere after the inspection was completed, but the above inspections are usually conducted every day. Therefore, the amount of gas released into the atmosphere is relatively large. However, in recent years, the deterioration of the global environment due to air pollution has become a serious problem, and the above-mentioned gas emissions are not desirable in terms of environmental conservation.

The present invention has been made in view of the above circumstances, and its purpose is to automate the monitoring of gas-insulated substation equipment, thereby saving labor, and to reduce the amount of gas sampled for the above-mentioned monitoring. An object of the present invention is to provide a monitoring device for gas-insulated substation equipment that can be recovered without using any special equipment and can contribute to environmental conservation.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a sampling means for automatically taking in filling gas in a closed tank of gas-insulated substation equipment, and A measuring means for generating a data signal indicating the concentration of a predetermined component in the gas is provided, and the sampling gas that has passed through the measuring means is placed in a sealed tank of another gas-insulated electrical equipment whose internal pressure is lower than that of the gas-insulated electrical substation equipment. The configuration is such that the

(Function) The filling gas in the closed tank is automatically taken in and sampled by the sampling means, and the concentration of a predetermined component is measured by the measuring means. At this time, when local overheating or corona discharge occurs in the sealed tank of gas-insulated substation equipment, the insulating gas filled inside changes chemically and decomposed gas is generated, and the insulating paper inside When natural deterioration occurs, gases such as co and Co2 are generated.

Therefore, if the measuring means is configured to measure the gas component generated as described above, the measuring means will automatically generate a data signal indicating the concentration of the gas component. It becomes possible to determine whether gas-insulated substation equipment is in a state that is a precursor to an accident.

Moreover, the gas subjected to component measurement by the measuring means is supplied into a sealed tank of another gas-insulated electrical equipment whose internal pressure is lower than that of the gas-insulated electrical substation equipment to be inspected. Therefore, the insulating gas can be recovered without being released into the atmosphere, contributing to atmospheric environmental conservation. In this case, the above-mentioned gas recovery can be performed using the internal pressure difference between different gas-insulated electrical devices, which eliminates the need for devices such as pumps and complicates the structure. , maintenance free can be achieved.

(Example) In FIG. 1, a gas insulated transformer 1, which is a gas insulated substation equipment, is constructed by filling a closed tank 3 in the shape of a pressure vessel containing a winding 2 with SF6 gas as an insulating gas.
A cooler 4 through which gas circulates is attached to the outside of the cooler. The gas insulated transformer 1 is integrally attached with a gas insulated disconnector 5, which is a gas insulated electric device, on the side thereof to form a unit. This gas insulated disconnect switch 5 is installed in a closed tank 5a in the form of a pressure vessel that houses a disconnect mechanism (not shown).
F. It is filled with gas and is connected to the primary side of the gas insulated transformer 1 via a through bushing 6, and is also connected to a power supply source (not shown) via a through bushing 7. There is. The filling gas pressure of the gas insulated transformer 1 is set to, for example, about 1.5 kg/c1, and the filling gas pressure of the gas insulated disconnector 5 is set to, for example, 0.3 kg/c1.
It is set at around kg/cm2.

The filling gas in the gas insulated transformer 1 can be sampled by a solenoid valve 8 serving as a sampling means. In other words, this solenoid valve 8 is configured to open when energized, and one end is communicated with the sealed tank 3 via a filter 9 and a nigga type plug 10, and the other end is communicated with the inspection unit 11. has been done. Therefore, when the solenoid valve 8 is energized with the cock 10 open, gas in the tank 3 is supplied to the inspection unit 11.

Now, the inspection unit 11 will be explained below.

That is, the sampling gas provided through the electromagnetic valve 8 is supplied to an infrared gas analyzer 12 serving as a measuring means via a capillary tube 13 for pressure reduction. Further, the analyzer 12 is supplied with N2 gas and reference gas for calibrating its measurement output from external cylinders 14 and 15. Specifically, cylinder 1
4 is filled with N2 gas, and the N2 gas is supplied to the solenoid valve 16. Pressure regulating valve 17 and capillary tube 18
The gas is supplied to the infrared gas analyzer 12 via the infrared gas analyzer 12. Also, in the cylinder 15, for example, CO2 gas is added to N2 gas at a concentration of 20%.
It is filled with a reference gas mixed at 0.00 PPM, and the reference gas is used in the solenoid valve 19 and the pressure regulating valve 1.
7. It is supplied to the infrared gas analyzer 12 via a capillary tube 18.

As will be understood from the description below, the infrared gas analyzer 12 is configured to sequentially exhaust the supplied gas, and the exhaust gas is passed through the flowmeter 20 and piping vibrator 21.
The gas is supplied into the closed tank 6 of the gas insulated disconnector 5 through the gas insulated disconnector 5.

FIG. 2 shows a schematic configuration of the infrared gas analyzer 12, which will be described below.

That is, as is well known, this gas analyzer 12 utilizes the fact that CO2 gas has the property of absorbing infrared rays of a specific wavelength, and from the infrared light source 22,
Infrared light whose center wavelength is the wavelength at which CO2 gas exhibits absorbency is output. The infrared rays outputted in this way are passed through a filter 24 that mainly passes infrared rays of a specific wavelength to which CO2 gas exhibits absorption, into the sample chamber 23 equipped with a gas inlet 23a and a gas outlet 23b. It is incident. The infrared rays that have passed through the sample chamber 23 are incident on the infrared sensor unit 27 via the fan-shaped slit 25a of the slitted disc 25 and the filter 26. At this time, the disk 25 is rotated at a constant speed by the motor 28, so that infrared rays are intermittently incident on the sensor unit 27, and its output signal is refreshed.

The sensor unit 27 is for measuring the level of incident infrared rays, and outputs a current signal corresponding to the difference between the measured level and a reference level as a data signal Sd indicating the concentration of CO2 gas through the preamplifier 29. do. The data signal Sd thus output is displayed on the indicator 30 as data indicating the CO2 gas concentration within the gas insulated transformer 1, and is also provided to the control circuit 31 shown in FIG.

The control circuit 31 is configured to include a microcomputer, and is configured to control the measurement of the C02 gas concentration by the inspection uni-soto 11 based on a preset sequence program. The contents and related operating procedures will be explained with reference to the timing chart of FIG.

That is, in order to measure the gas concentration, the cap 10 is opened and the pressure held by the pressure regulating valve 17 is adjusted to a predetermined level in advance. However, the control circuit 3
1 sequentially executes the control operations described below.

■For example, every 24 hours, when the power is turned on, the gas Ps
(time t1 in FIG. 3). When the power-on pulse Ps is output in this manner, the infrared gas analyzer 12 is powered on.

(2) At the same time as the power is turned on as described above, the solenoid valve 16 is opened continuously for, for example, one minute. As a result, the sample chamber 23 of the infrared gas analyzer 12 is filled with N2 gas supplied from the cylinder 14.

■At time tz when a predetermined time Δt shorter than one minute has passed since the start of the supply of N2 gas (the timing at which the sample chamber 23 is filled with N2 gas), the level of the data signal Sd output through the preamplifier 29 is, for example, 4 mA. The infrared gas analyzer 12 and two preamplifiers are calibrated so that Here, when the sample chamber 23 is filled with N2 gas, the concentration of CO2 gas is zero, so when the level of the data signal Sd is 4 mA, the infrared gas analyzer 1
The measured concentration according to 2 indicates a state of zero, and zero point calibration is thereby performed.

■At time t3, when N2 gas has been supplied for one minute, the solenoid valve 16 is shut off, and the solenoid valve 19 is turned off.
Open continuously for a minute. As a result, cylinder 15
A reference gas with a CO2 gas concentration of 2000 PPM is supplied to the infrared gas analyzer 12. As a result,
The N2 gas in the sample chamber 23 is replaced with the reference gas and CO2
Since the gas concentration increases, the level of the data signal Sd increases.

■At time ta when a predetermined time Δt has elapsed from the start of supply of the reference gas (timing when the level rise of the data signal Sd is saturated due to the sample chamber 23 being filled with the reference gas), the level of the data signal Sd is, for example, 20 mA.
The infrared gas analyzer 12 and two preamplifiers are calibrated so that Here, since the concentration of CO2 gas is 2000 PPM when the sample chamber 23 is filled with the reference gas, when the level of this data signal Sd is 20 mA, the concentration measured by the infrared gas analyzer 12 is 2000 PPM.
This indicates the state of the PM, and span calibration is performed based on this.

■At time t, when the reference gas has been supplied for one minute, the solenoid valve 19 is shut off and the solenoid valve 16 is turned off.
Open continuously for a minute. As a result, cylinder 14
The N2 gas inside is supplied to the infrared gas analyzer 12, and the reference gas inside the sample chamber 23 is replaced with N2 gas. Note that, if the level of the data signal Sd deviates from 4 mA corresponding to the zero point after such gas replacement, the above-mentioned zero point calibration and span calibration may be performed again.

(2) At time t6, when the N2 gas has been supplied for one minute, the solenoid valve 16 is shut off, and the solenoid valve 8 is continuously opened for a predetermined measurement time T. Thereby, the filling gas in the gas insulated transformer 1 is sampled and supplied to the infrared gas analyzer 12. Then, the level of the data signal Sd changes according to the C02a degree of the sampling gas.

■When the time tr (timing at which the level of the data signal Sci is saturated) is reached, when the measurement time T has elapsed from the start of sampling of the filling gas, the data signal Sd at that time is transferred to the CO2 in the gas insulated transformer 1. It is stored as a signal indicating the gas concentration.

Then, the stored data signal Sd is transmitted to an automatic diagnosis device for a substation system, which is a host device, through an online communication means.

After this, at time t6, when a predetermined period of time has passed after time t7 when the solenoid valve 8 is shut off, the level of the data signal Sd is switched to a forced zero state of 4 mA, and at time T9, when a predetermined period of time has elapsed, At this point, a power cutoff pulse Pe is output to cut off the power to the infrared gas analyzer 12. Note that when the infrared gas analyzer 12 is powered on and the level of the data signal Sd reaches OmA as shown by the two-dot chain line in FIG. 3, an interrupt is generated in the control circuit 31. Therefore, control circuit 3
1 generates an alarm signal indicating that an abnormality has occurred in the gas analyzer 12.

As a result of the above control, the zero point adjustment and span adjustment of the infrared gas analyzer 12 are performed every 24 hours, and the filling gas in the gas insulated transformer 1 is sampled and the amount of gas in the sampling gas is adjusted. The CO2 concentration is measured. Incidentally, FIG. 4 shows an outline of the control contents in the form of a flowchart to help understand the control operation by the control circuit 31 described above.

In short, according to the configuration of this embodiment described above, the measurement of the CO2 gas concentration generated within the gas insulated transformer 1 and the output of the data signal Sd indicating the measurement result are automatically performed. Therefore, the data signal Sd indicates a state in which the deterioration of insulating paper or the like progresses in the gas insulated transformer 1 and CO2 gas is generated, that is, a state that is a precursor to an accident.
Automatic monitoring and diagnosis based on

Further, the sampling gas used for measuring the CO2B degree in the infrared gas analyzer 12 is supplied to the sealed tank 5a of the gas insulated disconnector 5, which has an internal pressure lower than that of the gas insulated transformer 1 to be inspected. . Therefore, the gas containing SF6 as a main component sampled for measurement can be recovered without being released into the atmosphere, thereby contributing to environmental conservation of the atmosphere. Moreover, in this case, gas recovery is performed using the internal pressure difference between the gas insulated transformer 1 and the gas insulated disconnector 5, so devices such as pumps are not required, making the structure of the inspection device complicated. In addition to eliminating the risk of this happening, maintenance-free operation can be achieved.

In the above embodiment, the deterioration of the gas insulated transformer 1 is monitored by measuring the CO2 concentration in the gas filling the gas insulated transformer 1, but local overheating, corona discharge, etc. In order to monitor this, a configuration may be adopted that measures the presence or concentration of gases (such as So2.SOF2.HF) generated by decomposition of SF6 gas. Alternatively, a configuration may be adopted in which the sampling gas used for gas concentration measurement is supplied to a gas insulated switchgear (GIS), which is a gas insulated electrical device.

[Effects of the Invention] As described above, the present invention automatically samples the filling gas in the closed tank of gas-insulated substation equipment, measures the concentration of a predetermined component in the sampled gas, and displays the measurement results. Since the system is configured to generate data signals, gas-insulated substation equipment can be automatically monitored, resulting in labor savings. Furthermore, the present invention has a configuration in which the sampling gas used for measurement is supplied to other gas-insulated electric equipment whose internal pressure is lower than that of the gas-insulated substation equipment to be monitored, so that no extra equipment is required for supplying the insulating gas. It can be recovered with a maintenance-free structure and can greatly contribute to environmental conservation.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an overall configuration diagram that practically shows the state of the piping, FIG. 2 is a schematic configuration diagram of the measuring means, and FIG. 3 is a timing chart for explaining the operation. ,
FIG. 4 is a flowchart showing an outline of the operation contents. In the drawing, 1 is a gas insulated transformer (gas insulated substation equipment), 3
5 is a closed tank, 5 is a gas insulated disconnector (gas insulated electrical equipment), 8 is a solenoid valve (sampling means), 11 is an inspection unit, 12 is an infrared gas analyzer (measuring means), and 31 is a control circuit.

Claims (1)

[Claims] 1. Equipped with a sampling means that automatically takes in the filling gas in the closed tank of the gas-insulated substation equipment, and a measuring means that measures the concentration of a predetermined component in the sampling gas and generates a data signal indicating the measured concentration. . A monitoring device for gas-insulated electrical substation equipment, characterized in that the sampling gas that has passed through the measuring means is supplied into a closed tank of another gas-insulated electrical equipment whose internal pressure is lower than that of the gas-insulated electrical equipment.