CN104659700A - Automatic gas filling warning device of SF6 gas insulated metal closed switch equipment - Google Patents

Abstract

Aiming at the defects or deficiencies of the above-mentioned existing artificial SF ₆ inflating devices, an automatic inflating alarm device for SF ₆ gas-insulated metal-enclosed switchgear is disclosed. Consider determining the automatic stop of SF ₆ inflation work based on the rated working pressure of the closed switch air chamber, determine the gas tank switching according to the air pressure and weight of the gas tank, and issue corresponding alarms according to the environmental status and inflation state detection, and develop a set of SF ₆ inflation automatic stop , alarm, switching and monitoring devices, standardize, intelligentize and automate the GIS inflation work, ensure the inflation quality, improve the inflation efficiency, make GIS inflation safer, more efficient and economical, and can effectively ensure the insulation strength and arc extinguishing of closed switchgear gas ability.

Description

A SF6 gas-insulated metal-enclosed switchgear automatic filling alarm device

technical field

The invention belongs to the technical field of automatic control of high-voltage gas-enclosed switchgear in electrical engineering, and in particular relates to a device for automatically filling and alarming gas-insulated-enclosed switchgear (GIS) equipment.

Background technique

With the development of the power grid, its voltage level is getting higher and higher, and the short-circuit capacity is also getting bigger and bigger, and the requirements for the insulation strength and arc extinguishing ability of the power grid equipment are getting higher and higher. In response to these requirements, due to the strong electronegativity of sulfur hexafluoride (SF ₆ ) gas, it has excellent insulation performance and arc extinguishing performance, and has been widely used in the field of high-voltage switches to break circuits at high-voltage and ultra-high voltage levels It is widely used in equipment such as switchgear and gas-insulated metal-enclosed switchgear (GIS), and it has also gradually penetrated into the medium and low voltage fields. In particular, since GIS installs circuit breakers, disconnectors, busbars, grounding switches, transformers, outlet bushings or cable terminals in their respective sealed rooms to form an integral shell, and fills it with SF ₆ gas as an insulating medium, It has the advantages of compact structure, small size, light weight, not affected by atmospheric conditions, long maintenance intervals, no electric shock accidents and electrical noise interference, etc., and has become the first choice for urban substations.

Now SF ₆ has become the most important insulating and arc-extinguishing gas medium in the power grid. However, although pure SF ₆ gas has excellent insulation properties and arc extinguishing properties, its electrical properties will deteriorate significantly as its purity decreases, especially when the gas purity does not meet the specified requirements. For example, it is stipulated in relevant standards that the gas purity of SF ₆ in operation shall not be lower than 97%. During the operation of the equipment, SF ₆ decomposes due to large current breaking and discharge faults, producing oxygen, water and other decomposition compounds, which not only degrades the insulating materials, but also corrodes the metal materials of the equipment. In particular, the increase of moisture content will directly affect the insulation performance, breaking performance and mechanical performance. Therefore, in order to give full play to the excellent insulation and arc extinguishing properties of SF ₆ gas, it is necessary to replace SF ₆ gas in equipment that does not meet the SF ₆ standard in time to ensure the safe operation of electrical equipment.

In fact, most of the existing SF ₆ inflation systems rely on manual work, requiring staff to determine whether the inflation is complete based on the barometer readings of the GIS gas chamber (a closed space filled with SF ₆ gas) on the spot, and to determine whether the inflation is complete according to the pressure tank pressure. The meter reading determines whether the air tank needs to be replaced. For a standard air chamber, it often takes 10-15 days to complete all air changes, and the entire inflation efficiency is low. At the filling site, the staff often judge whether the gas is frozen according to the reading speed of the air chamber or the gas tank barometer, so as to decide whether the gas tank needs to be replaced. However, due to the difference in the judgment ability of the staff, it may lead to When there is more sulfur hexafluoride gas, it is replaced, resulting in a waste of resources. In the process of artificial inflation, because the time interval for the staff to read the barometer is long and the speed of operating the valve is slow, it is easy to cause the pressure of the air chamber to be too high, which not only causes a waste of resources, but also increases the cost of putting the substation into operation. time. When artificially inflating, on the one hand, it may be caused by the operator's operation error, which may lead to the entry of water, air and other impurities, making it difficult to ensure the quality of ventilation. On the other hand, it may lead to the emission of sulfur hexafluoride gas into the air, leading to the aggravation of the greenhouse effect, and may lead to the deposition of sulfur hexafluoride gas with a higher density than air in low-lying places such as cable trenches in substations , causing the oxygen content inside to drop, which may cause personal injury to the staff when it is lower than the rated value specified in the regulations.

Contents of the invention

In view of the defects or insufficiencies of the existing artificial SF ₆ inflation devices mentioned above, it is considered to determine the automatic stop of the SF ₆ inflation work according to the rated working pressure of the closed switch chamber, determine the gas tank switching according to the air pressure and weight of the gas tank, and determine the gas tank switching according to the environmental status and inflation pressure. State detection sends corresponding alarms, develops a set of SF ₆ inflation automatic stop, alarm, switching and monitoring devices, standardizes, intelligentizes and automates GIS inflation work, ensures inflation quality, improves inflation efficiency, and makes GIS inflation safer, more efficient and more efficient It is economical and can effectively guarantee the insulation strength and arc extinguishing ability of the closed switchgear gas.

The technical solution adopted to realize the object of the present invention is as follows, a kind of SF ₆ gas insulated metal-enclosed switchgear automatic filling alarm device, it is characterized in that: it includes the first air chamber, the second air chamber and the third air chamber supply The first gas tank, the second gas tank, the third gas tank and the fourth gas tank of SF ₆ gas.

The first gas tank, the second gas tank, the third gas tank and the fourth gas tank are respectively placed on the first weight sensor, the second weight sensor, the third weight sensor and the fourth weight sensor

The gas outlet of the first gas tank is connected to the main pipeline through the first gas tank branch pipe, and the first gas tank valve is installed on the first gas tank branch pipe.

The gas outlet of the second gas tank is connected to the main pipeline through a second gas tank branch pipe, and a second gas tank valve is installed on the second gas tank branch pipe.

The gas outlet of the third gas tank is connected to the main pipeline through a third gas tank branch pipe, and a third gas tank valve is installed on the third gas tank branch pipe.

The gas outlet of the fourth gas tank is connected to the main pipeline through the branch pipe of the fourth gas tank, and the valve of the fourth gas tank is installed on the branch pipe of the fourth gas tank.

The main pipe is also communicated with the intake ends of the first air chamber branch pipe, the second air chamber branch pipe and the third air chamber branch pipe.

The gas outlet end of the branch pipe of the first air chamber is connected to the first air chamber. A first air chamber valve is installed on the first air chamber branch pipe. The branch pipe of the first gas chamber is also equipped with a first flow sensor for measuring the gas flow in the tube, a first air pressure sensor for measuring the gas pressure in the tube, and a first temperature sensor for measuring the gas temperature in the tube.

The gas outlet end of the branch pipe of the second air chamber is connected to the second air chamber. A second air chamber valve is installed on the branch pipe of the second air chamber. The branch pipe of the second air chamber is also equipped with a second flow sensor for measuring the gas flow in the tube, a second air pressure sensor for measuring the gas pressure in the tube, and a second temperature sensor for measuring the gas temperature in the tube.

The gas outlet end of the branch pipe of the third air chamber is connected to the third air chamber. A third air chamber valve is installed on the branch pipe of the third air chamber. The branch pipe of the third air chamber is also equipped with a third flow sensor for measuring the gas flow in the tube, a third air pressure sensor for measuring the gas pressure in the tube, and a third temperature sensor for measuring the gas temperature in the tube.

The first flow sensor, the second flow sensor and the third flow sensor respectively measure the gas flow in the pipe: Q ₁ , Q ₂ and Q ₃ .

Open at least one of the first gas tank valve, the second gas tank valve, the third gas tank valve and the fourth gas tank valve, and at the same time, open the first gas chamber valve, the second gas chamber valve and the third gas chamber valve at least one of the .

If the valve of the first air chamber is open, when Q ₁ <0.1L/s, close the opened valves of the first, second, third, and fourth air tank valves, and replace them. corresponding gas tank.

If the valve of the second air chamber is open, when Q ₂ <0.1L/s, close the opened valves of the first, second, third, and fourth air tank valves, and replace them. corresponding gas tank.

If the valve of the third air chamber is open, when Q ₃ <0.1L/s, close the opened valves of the valves of the first air tank, the second air tank, the third air tank and the fourth air tank, and replace them corresponding gas tank.

The first air pressure sensor, the second air pressure sensor and the third air pressure sensor respectively measure the gas pressure in the tube: P ₁ , P ₂ and P ₃ .

Open at least one of the first gas tank valve, the second gas tank valve, the third gas tank valve and the fourth gas tank valve, and at the same time, open the first gas chamber valve, the second gas chamber valve and the third gas chamber valve at least one of the .

If the valve of the first air chamber is open, when P ₁ ≥ _Pe , close the valve of the first air chamber. Among them, P _e is the rated value set by the regulations. For example, for a 110 kV GIS combined electrical appliance, the rated air pressure of the circuit breaker air chamber is 0.6Mpa (gauge pressure 20°C), and the rated air pressure of other air chambers is 0.4Mpa ( Gauge pressure 20°C).

If the valve of the second air chamber is open, when P ₂ ≥ _Pe , close the valve of the second air chamber.

If the valve of the third air chamber is open, when P ₃ ≥ _Pe , close the valve of the third air chamber.

The first temperature sensor, the second temperature sensor and the third temperature sensor respectively measure the gas temperature in the tube: t ₁ , t ₂ and t ₃ .

Open at least one of the first gas tank valve, the second gas tank valve, the third gas tank valve and the fourth gas tank valve, and at the same time, open the first gas chamber valve, the second gas chamber valve and the third gas chamber valve at least one of the .

If the valve of the first air chamber is open, when t ₁ >60°C, close the valve of the first air chamber.

If the valve of the second air chamber is open, when t ₂ >60°C, close the valve of the second air chamber.

If the valve of the third air chamber is open, when t ₃ >60°C, close the valve of the third air chamber.

The first weight sensor, the second weight sensor, the third weight sensor and the fourth weight sensor respectively measure the weights m ₁ , m ₂ , m ₃ and m ₄ .

When m ₁ ≤ m _s , close the valve of the first gas tank and replace the first gas tank. Among them, m _s is the set threshold value. Generally, different manufacturers of sulfur hexafluoride gas tanks have different values. For a general 38-40L gas tank, the value is about 50kg.

When m ₂ ≤ m _s , close the valve of the second gas tank and replace the second gas tank.

When m ₃ ≤ m _s , close the valve of the third gas tank and replace the third gas tank.

When m ₄ ≤ m _s , close the valve of the fourth gas tank and replace the fourth gas tank.

The ambient temperature and humidity sensor placed near the device or installed on the main pipeline measures the ambient temperature t _en and ambient humidity RH _en of the area where the device is located.

Open at least one of the first gas tank valve, the second gas tank valve, the third gas tank valve and the fourth gas tank valve, and at the same time, open the first gas chamber valve, the second gas chamber valve and the third gas chamber valve at least one of the .

If RH _en >90% or t _en >60°C, close all valves, stop inflation, and send out an alarm.

If it is not in the inflation process, the valve is closed to prohibit inflation and an alarm is issued.

The present invention mainly has following effect:

(1) Open the electromagnetic valve through computer control, and check whether the ambient temperature and humidity t and RH meet the requirements of the regulations, that is, the temperature must be lower than 60°C, and the relative humidity must be less than 90%; if the requirements are not met, close the valve to stop inflation.

(2) The automatic inflation device can measure the SF ₆ gas flow Q at the same time, and calculate the gas volume V ₀ required for the closed switch gas chamber according to the relationship between the air pressure P of the closed switch gas chamber, the volume V, and the temperature t, so as to obtain the automatic inflation prediction required time t;

(3) measure air tank air pressure P ₁ and weight M ₁ , according to new bottle SF ₆ weight M _bottle and volume V _bottle , utilize formula M _leftover =M ₁ -M _bottle to calculate SF ₆ gas tank remaining gas amount M _leftover , when remaining When the gas volume is less than the threshold m _s , an alarm for replacing the gas tank is issued;

(4) When the inflation time reaches the previously calculated required time t, measure whether the air pressure P of the air chamber of the gas-enclosed switch meets the rated required value P _e , and if it does not meet the requirements (P≤P _e ), re-according to the air chamber air pressure and The flow rate is corrected for the time; when the requirement (P≥P _e ) is met, the valve is closed to complete the inflation.

(5) When the device is used to inflate multiple air chambers, the multiple air chambers are connected to the gas tank, and each air chamber is connected to a gas delivery pipe equipped with a controllable valve and a sensor, as shown in FIG. 3 . When the valve is opened for inflation, the gas state is detected by the sensor. When the ambient temperature, humidity and gas temperature do not meet the requirements, the valve is closed to stop inflation; when the air pressure of the air chamber 1 meets the requirements, the controllable valve 1 of the air chamber is closed. , the air chamber is inflated, and the other air chambers continue to inflate.

Description of drawings

Fig. 1 is a structural diagram of the present invention.

Fig. 2 is a schematic diagram of simultaneous inflation and connection of multiple air chambers of the present invention.

Figure 3 is a diagram of the location of the weight sensor.

Fig. 4 is a flow chart for judging the software of the control system of the automatic inflation device.

In the figure: gas tank (1), gas tank valve (2), gas chamber valve (5), flow sensor (6), air pressure sensor (7), temperature sensor (8), gas chamber (9), weight sensor ( 11), an ambient temperature and humidity sensor (12), a movable platform (13), a computer (14), and an operating table (15). The first gas tank (101), the second gas tank (102), the third gas tank (103), the fourth gas tank (104), the first weight sensor (111), the second weight sensor (112), the third Weight sensor (113), the fourth weight sensor (114), the first gas tank valve (201), the second gas tank valve (202), the third gas tank valve (203), the fourth gas tank valve (204), The first gas tank branch pipe (301), the second gas tank branch pipe (302), the third gas tank branch pipe (303), the fourth gas tank branch pipe (304), the first gas chamber branch pipe (401), the second gas chamber branch pipe (402), third air chamber branch pipe (403), first air chamber valve (501), second air chamber valve (502), third air chamber valve (503), first flow sensor (601), second air chamber valve Flow sensor (602), third flow sensor (603), first air pressure sensor (701), second air pressure sensor (702), third air pressure sensor (703), first temperature sensor (801), second temperature sensor (802), a third temperature sensor (803), a first air chamber (901), a second air chamber (902), and a third air chamber (903).

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but it should not be understood that the scope of the subject matter of the present invention is limited to the following embodiments. Without departing from the above-mentioned technical ideas of the present invention, various replacements and changes made according to common technical knowledge and conventional means in this field shall be included in the protection scope of the present invention.

Example 1:

A SF ₆ gas insulated metal-enclosed switchgear automatic charging alarm device, characterized in that it includes a first gas tank 101 for supplying SF ₆ gas to the first gas chamber 901, the second gas chamber 902 and the third gas chamber 903, and a second gas tank 101 Two gas tanks 102 , a third gas tank 103 and a fourth gas tank 104 .

The first gas tank 101, the second gas tank 102, the third gas tank 103 and the fourth gas tank 104 are respectively placed on the first weight sensor 111, the second weight sensor 112, the third weight sensor 113 and the fourth weight sensor 114

The gas outlet of the first gas tank 101 is connected to the main pipeline 16 through a first gas tank branch pipe 301 , and a first gas tank valve 201 is installed on the first gas tank branch pipe 301 .

The gas outlet of the second gas tank 102 is connected to the main pipeline 16 through the second gas tank branch pipe 302 , and the second gas tank valve 202 is installed on the second gas tank branch pipe 302 .

The gas outlet of the third gas tank 103 is connected to the main pipeline 16 through a third gas tank branch pipe 303 , and a third gas tank valve 203 is installed on the third gas tank branch pipe 303 .

The gas outlet of the fourth gas tank 104 is connected to the main pipeline 16 through the fourth gas tank branch pipe 304 , and the fourth gas tank valve 204 is installed on the fourth gas tank branch pipe 304 .

The main pipe 16 is also in communication with the intake ends of the first air chamber branch pipe 401 , the second air chamber branch pipe 402 and the third air chamber branch pipe 403 .

The gas outlet end of the first air chamber branch pipe 401 is connected to the first air chamber 901 . A first air chamber valve 501 is installed on the first air chamber branch pipe 401 . The first gas chamber branch pipe 401 is also equipped with a first flow sensor 601 for measuring the gas flow in the pipe, a first air pressure sensor 701 for measuring the gas pressure in the pipe, and a first temperature sensor 801 for measuring the gas temperature in the pipe.

The gas outlet end of the second air chamber branch pipe 402 is connected to the second air chamber 902 . A second air chamber valve 502 is installed on the second air chamber branch pipe 402 . The second gas chamber branch pipe 402 is also equipped with a second flow sensor 602 for measuring the gas flow in the tube, a second air pressure sensor 702 for measuring the gas pressure in the tube, and a second temperature sensor 802 for measuring the gas temperature in the tube.

The gas outlet end of the third air chamber branch pipe 403 is connected to the third air chamber 903 . A third air chamber valve 503 is installed on the third air chamber branch pipe 403 . The third gas chamber branch pipe 403 is also equipped with a third flow sensor 603 for measuring the gas flow in the pipe, a third air pressure sensor 703 for measuring the gas pressure in the pipe, and a third temperature sensor 803 for measuring the gas temperature in the pipe.

Example 2:

A kind of control SF ₆ gas-insulated metal-enclosed switchgear automatic inflation method adopting the device described in embodiment 1:

The first flow sensor 601 , the second flow sensor 602 and the third flow sensor 603 respectively measure the gas flow in the pipe: Q ₁ , Q ₂ and Q ₃ .

Open at least one of the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204, and at the same time, open the first gas chamber valve 501, the second gas chamber valve 502 and At least one of the third air chamber valves 503 .

If the first gas chamber valve 501 is open, when Q ₁ <0.1L/s, close the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204 which have been opened valve, and replace the corresponding gas tank.

If the second gas chamber valve 502 is open, when Q ₂ <0.1L/s, close the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204 that have been opened valve, and replace the corresponding gas tank.

If the third gas chamber valve 503 is opened, when Q ₃ <0.1L/s, close the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204 that have been opened valve, and replace the corresponding gas tank.

Example 3:

A kind of control SF ₆ gas-insulated metal-enclosed switchgear automatic inflation method adopting the device described in embodiment 1:

The first air pressure sensor 701 , the second air pressure sensor 702 and the third air pressure sensor 703 respectively measure the gas pressure in the tube: P ₁ , P ₂ and P ₃ .

Open at least one of the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204, and at the same time, open the first gas chamber valve 501, the second gas chamber valve 502 and At least one of the third air chamber valves 503 .

If the first air chamber valve 501 is open, when P ₁ ≥ _Pe , close the first air chamber valve 501 .

If the second air chamber valve 502 is open, when P ₂ ≥ _Pe , close the second air chamber valve 502 .

If the third air chamber valve 503 is open, when P ₃ ≥ _Pe , close the third air chamber valve 503 .

Example 4:

A kind of control SF ₆ gas-insulated metal-enclosed switchgear automatic inflation method adopting the device described in embodiment 1:

The first temperature sensor 801 , the second temperature sensor 802 and the third temperature sensor 803 respectively measure the gas temperature in the tube: t ₁ , t ₂ and t ₃ .

Open at least one of the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204, and at the same time, open the first gas chamber valve 501, the second gas chamber valve 502 and At least one of the third air chamber valves 503 .

If the first air chamber valve 501 is open, when t ₁ >60°C, close the first air chamber valve 501 .

If the second air chamber valve 502 is open, when t ₂ >60°C, close the second air chamber valve 502 .

If the third air chamber valve 503 is open, when t ₃ >60°C, the third air chamber valve 503 is closed.

Example 5:

A kind of control SF ₆ gas-insulated metal-enclosed switchgear automatic inflation method adopting the device described in embodiment 1:

The first weight sensor 111, the second weight sensor 112, the third weight sensor 113 and the fourth weight sensor 114 respectively measure the first gas tank 101, the second gas tank 102, the third gas tank 103 and the fourth gas tank 104 The weight m ₁ , m ₂ , m ₃ and m ₄ .

When m ₁ ≤ m _s , close the valve 201 of the first gas tank, and replace the first gas tank 101 .

When m ₂ ≤ m _s , close the valve 202 of the second gas tank, and replace the second gas tank 102 .

When m ₃ ≤ m _s , close the valve 203 of the third gas tank, and replace the third gas tank 103 .

When m ₄ ≤ m _s , close the valve 204 of the fourth gas tank, and replace the fourth gas tank 104 .

Embodiment 6:

A method for controlling the automatic inflation of SF ₆ gas-insulated metal-enclosed switchgear using the device described in Embodiment 1: the ambient temperature and humidity sensor 12 measures the ambient temperature t _en and ambient humidity RH _en of the area where the device is located.

Open at least one of the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204, and at the same time, open the first gas chamber valve 501, the second gas chamber valve 502 and At least one of the third air chamber valves 503 .

If RH _en >90% or t _en >60°C, close all valves, stop inflation, and send out an alarm.

Embodiment 7:

A kind of control SF ₆ gas-insulated metal-enclosed switchgear automatic inflation method adopting the device described in embodiment 1:

Open the first gas tank valve 201, the second gas tank valve 202, the third gas tank valve 203 and the fourth gas tank valve 204, and at the same time, open the first gas chamber valve 501, the second gas chamber valve 502 and the third gas chamber Valve 503.

The first flow sensor 601 , the second flow sensor 602 and the third flow sensor 603 respectively measure the gas flow in the pipe: Q ₁ , Q ₂ and Q ₃ .

The first air pressure sensor 701 , the second air pressure sensor 702 and the third air pressure sensor 703 respectively measure the gas pressure in the tube: P ₁ , P ₂ and P ₃ .

The first temperature sensor 801 , the second temperature sensor 802 and the third temperature sensor 803 respectively measure the gas temperature in the tube: t ₁ , t ₂ and t ₃ .

The first weight sensor 111, the second weight sensor 112, the third weight sensor 113 and the fourth weight sensor 114 respectively measure the first gas tank 101, the second gas tank 102, the third gas tank 103 and the fourth gas tank 104 The weight m ₁ , m ₂ , m ₃ and m ₄ .

The ambient temperature and humidity sensor 12 measures the ambient temperature t _en and the ambient humidity RH _en of the area where the device is located.

The corresponding relationship between the opening and closing of the valve of the entire automatic inflation system and the data collected by the sensor is as follows:

Table 1 Correspondence between the data collected by the sensor and the opening and closing of the valve

The _pe in the table is the rated pressure of the air chamber specified in the regulations, which is 0.6Mpa (gauge pressure 20°C) for the circuit breaker air chamber and 0.4Mpa (gauge pressure 20°C) for other air chambers. m _s is the sum of the weight of the gas tank and the weight of sulfur hexafluoride gas that cannot inflate the gas chamber because the air pressure is too low. For a general 38-40L gas tank, the value is about 50kg.

Claims (5)

1. A kind of SF ₆ gas insulated metal-enclosed switchgear automatic charging alarm device, it is characterized in that: comprise to the first gas chamber (901), the second gas chamber (902) and the 3rd gas chamber (903) supply SF ₆ gas The first gas tank (101), the second gas tank (102), the third gas tank (103) and the fourth gas tank (104); The first gas tank (101), the second gas tank (102), the third gas tank (103) and the fourth gas tank (104) are respectively placed on the first weight sensor (111), the second weight sensor (112) ), the third weight sensor (113) and the fourth weight sensor (114); The gas outlet of the first gas tank (101) is connected to the main pipeline (16) through the first gas tank branch pipe (301), and the first gas tank valve (201) is installed on the first gas tank branch pipe (301) ; The gas outlet of the second gas tank (102) is connected with the main pipeline (16) through the second gas tank branch pipe (302), and the second gas tank valve (202) is installed on the second gas tank branch pipe (302) ; The gas outlet of the third gas tank (13) is connected with the main pipeline (16) through the third gas tank branch pipe (303), and the third gas tank valve (203) is installed on the third gas tank branch pipe (303) ; The gas outlet of the fourth gas tank (104) is connected with the main pipeline (16) through the fourth gas tank branch pipe (304), and the fourth gas tank valve (204) is installed on the fourth gas tank branch pipe (304) ; The main pipeline (16) is also communicated with the air intake ends of the air chamber branch pipe (401), the second air chamber branch pipe (402) and the third air chamber branch pipe (403); The gas outlet end of the first gas chamber branch pipe (401) is connected to the first gas chamber (901); the first gas chamber branch pipe (401) is equipped with a first gas chamber valve (501); The chamber branch pipe (401) is also equipped with a first flow sensor (601) for measuring the gas flow in the tube, an air pressure sensor (701) for measuring the gas pressure in the tube, and a first temperature sensor (801) for measuring the gas temperature in the tube; The gas outlet end of the second gas chamber branch pipe (402) is connected to the second gas chamber (902); the second gas chamber branch pipe (402) is equipped with a second gas chamber valve (502); The second flow sensor (602) for measuring the gas flow in the tube, the second air pressure sensor (702) for measuring the gas pressure in the tube, and the second temperature sensor (802) for measuring the gas temperature in the tube are also installed on the chamber branch pipe (402); The air outlet end of the third air chamber branch pipe (403) is connected to the third air chamber (903); the third air chamber branch pipe (403) is equipped with a third air chamber valve (503); the third air chamber branch pipe (403) is equipped with a third air chamber valve (503); The chamber branch pipe (403) is also equipped with a third flow sensor (603) for measuring the gas flow in the tube, a third air pressure sensor (703) for measuring the gas pressure in the tube, and a third temperature sensor (803) for measuring the gas temperature in the tube. 2. adopt a kind of control _SF6 gas-insulated metal-enclosed switchgear automatic inflation method of adopting the described device of claim 1, it is characterized in that: The first flow sensor (601), the second flow sensor (602) and the third flow sensor (603) respectively measure the gas flow in the pipe: Q ₁ , Q ₂ and Q ₃ ; Open at least one of the first gas tank valve (201), the second gas tank valve (202), the third gas tank valve (203) and the fourth gas tank valve (204), and at the same time, open the first gas chamber valve ( 501), at least one of the second air chamber valve (502) and the third air chamber valve (503); If the first gas chamber valve (501) is open, when Q ₁ <0.1L/s, close the first gas tank valve (201), the second gas tank valve (202), the third gas tank valve (203) and the Open the valve in the four gas tank valves (204), and replace the corresponding gas tank; If the second air chamber valve (502) is open, when Q ₂ <0.1L/s, close the first air tank valve (201), the second air tank valve (202), the third air tank valve (203) and the third air tank valve Open the valve in the four gas tank valves (204), and replace the corresponding gas tank; If the third gas chamber valve (503) is open, when Q ₃ <0.1L/s, close the first gas tank valve (201), the second gas tank valve (202), the third gas tank valve (203) and the third gas tank valve Open the valves in the four gas tank valves (204), and replace the corresponding gas tanks. 3. adopt a kind of control _SF6 gas-insulated metal-enclosed switchgear automatic inflation method of adopting the described device of claim 1, it is characterized in that: The first air pressure sensor (701), the second air pressure sensor (702) and the third air pressure sensor (703) respectively measure the gas pressure in the tube: P ₁ , P ₂ and P ₃ ; Open at least one of the first gas tank valve (201), the second gas tank valve (202), the third gas tank valve (203) and the fourth gas tank valve (204), and at the same time, open the first gas chamber valve ( 501), at least one of the second air chamber valve (502) and the third air chamber valve (503); If the first air chamber valve (501) is open, when P ₁ ≥ _{P e} , close the first air chamber valve (501); where P _e is the rated value set by the regulations, for example, for a 110 kV GIS combined electrical appliance , the rated air pressure of the circuit breaker air chamber is 0.6Mpa (gauge pressure 20°C), and the rated air pressure of other air chambers is 0.4Mpa (gauge pressure 20°C), the same below; If the second air chamber valve (502) is opened, when P ₂ ≥ P _e , close the second air chamber valve (502); If the third air chamber valve (503) is open, when P ₃ ≥ _Pe , close the third air chamber valve (503). 4. adopt a kind of control _SF6 gas-insulated metal-enclosed switchgear automatic inflation method of adopting the described device of claim 1, it is characterized in that: The first temperature sensor (801), the second temperature sensor (802) and the third temperature sensor (803) respectively measure the gas temperature in the tube: t ₁ , t ₂ and t ₃ ; Open at least one of the first gas tank valve (201), the second gas tank valve (202), the third gas tank valve (203) and the fourth gas tank valve (204), and at the same time, open the first gas chamber valve ( 501), at least one of the second air chamber valve (502) and the third air chamber valve (503); If the first air chamber valve (501) is open, when t ₁ >60°C, close the first air chamber valve (501) according to relevant national standards and electric power standards; If the second air chamber valve (502) is open, when t ₂ >60°C, close the second air chamber valve (502) according to relevant national standards and electric power standards; If the third air chamber valve (503) is open, when t ₃ >60°C, close the third air chamber valve (503) according to relevant national standards and electric power standards. 5. adopt a kind of control _SF6 gas-insulated metal-enclosed switchgear automatic inflation method of adopting the described device of claim 1, it is characterized in that: The first weight sensor (111), the second weight sensor (112), the third weight sensor (113) and the fourth weight sensor (114) respectively measure the first gas tank (101), the second gas tank (102) , the weight m ₁ , m ₂ , m ₃ and m ₄ of the third gas tank (103) and the fourth gas tank (104); When m ₁ ≤ m _s , close the valve (201) of the first gas tank, and replace the first gas tank (101); where m _s is a set threshold, which is generally different from the value of the manufacturer of the sulfur hexafluoride gas tank Not the same, for a general 38-40L gas tank, the value is about 50kg, the same below; When m ₂ ≤ m _s , close the second gas tank valve (202), and replace the second gas tank (102); When m ₃ ≤ m _s , close the third gas tank valve (203), and replace the third gas tank (103); When m ₄ ≤ m _s , close the fourth gas tank valve (204), and replace the fourth gas tank (104). 6. A method for controlling the automatic inflation of SF ₆ gas-insulated metal-enclosed switchgear using the device described in claim 1, characterized in that: the ambient temperature and humidity sensor (12) measures the ambient temperature t _en and ambient humidity RH _en in the area where the device is located ; Open at least one of the first gas tank valve (201), the second gas tank valve (202), the third gas tank valve (203) and the fourth gas tank valve (204), and at the same time, open the first gas chamber valve ( 501), at least one of the second air chamber valve (502) and the third air chamber valve (503); If RH _en >90% or t _en >60°C, close all valves, stop inflation, and send out an alarm; When not in the inflation process, if RH _en > 90% or t _en > 60°C, the valve will be closed, inflation is prohibited, and an alarm will be issued.