Device and method for evaluating insulation state of insulating gas

Abstract

The invention provides a device and a method for evaluating the insulation state of insulating gas, and relates to the technical field of high-voltage technology and electrical equipment insulation detection. The device comprises a high-voltage discharge module, a gas conveying module and a detection module, one end of the gas conveying module is communicated with the high-voltage discharge module, and the other end is communicated with the gas insulation combined electric appliance and used for obtaining insulation gas in the gas insulation combined electric appliance and conveying the insulation gas into the high-voltage discharge module; the air pressure of the insulating gas in the high-voltage discharge module is lower than that in the gas insulated switchgear; and the detection module supplies power to the high-voltage discharge module and is used for puncturing the insulating gas to form a closed loop with the detection module to obtain a discharge voltage value. The low-pressure discharge process is adopted to evaluate the insulation state of the insulation gas, the gas discharge voltage is reduced, the safety is improved, and the insulation performance of the insulation gas can be safely, simply, conveniently and efficiently evaluated by arranging the insulation state evaluation device for the insulation gas on the high-voltage electrical equipment site.

Description

Technical Field

[0001] The present invention relates to the field of high voltage technology and electrical equipment insulation detection technology, and in particular to an insulating gas insulation state evaluation device and method. Background Art

[0002] Gas insulated switchgear (GIS) has been widely used in high voltage, ultra-high voltage and ultra-high voltage power transmission and transformation fields due to its compact structure, high reliability, low electromagnetic pollution and low maintenance workload. However, many GIS equipment put into operation early are facing increasingly serious insulation aging problems, and equipment failures occur from time to time, which not only endangers the reliable operation of the entire power grid system, but also brings many inconveniences and serious economic losses to social production and life. Therefore, how to accurately evaluate the insulation status according to the actual operation status of GIS and effectively identify various types of latent insulation faults is not only an important part of ensuring the safe operation of GIS equipment, but also has important theoretical value and practical engineering significance for realizing the condition maintenance and full life cycle management of GIS equipment. At present, the insulation status evaluation of GIS equipment is mainly achieved by detecting and evaluating the status of the insulating gas inside the GIS equipment. By evaluating the status of the insulating gas, the insulation defects inside the equipment can be discovered in time. In the current power system, sulfur hexafluoride (SF6) is widely used in high voltage electrical equipment such as gas insulated switchgear (GIS). This evaluation process involves knowledge from multiple disciplines, and one of the key points is to determine whether the gas insulation performance has declined through the gas discharge principle in physics. Of course, in other aspects, such as analyzing the gas decomposition products (these decomposition products may be signs of faults such as partial discharge inside the equipment), detecting gas pressure, humidity and other parameters, etc., to comprehensively evaluate whether the insulating gas can maintain a normal insulation state and ensure the safe and stable operation of electrical equipment.

[0003] The existing insulation gas fault assessment method is based on the industry standard and group standard DL / T1986-2019 "Technical Specifications for Gas Detection of Sulfur Hexafluoride Mixed Gas Insulation Equipment" and T / CEC568-2021 "Calibration and Field Detection Methods for SF6 / N2 Mixed Gas Mixture Ratio Detector", which takes the insulation gas components as the detection target and needs to include sampling, testing and safety precautions on site and in the laboratory. Since the content of the decomposition components of the insulation gas is extremely low, the gas needs to be taken to the laboratory for testing after sampling to obtain accurate results, and its detection cycle is relatively long.

[0004] Therefore, how to safely, simply and efficiently evaluate the insulation performance of the insulating gas in a gas-insulated switchgear (GIS device) device at the installation site of the GIS device is a technical problem that technical personnel in the field urgently need to solve. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for evaluating the insulation state of an insulating gas, so as to reduce the discharge voltage of the insulating gas and realize safe, simple and efficient evaluation of the insulation performance of the insulating gas.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An insulating gas insulation state assessment device comprises a high-voltage discharge module, a gas delivery module and a detection module; one end of the gas delivery module is connected to the high-voltage discharge module, and the other end is connected to a gas-insulated combined electrical appliance, and is used to obtain the insulating gas in the gas-insulated combined electrical appliance and deliver it to the high-voltage discharge module; the gas pressure of the insulating gas in the high-voltage discharge module is lower than the gas pressure in the gas-insulated combined electrical appliance; the detection module supplies power to the high-voltage discharge module, and is used to break down the insulating gas to form a closed loop with the detection module to obtain a discharge voltage value.

[0008] In order to easily obtain the insulating gas in the gas-insulated combination electrical appliance, the present invention provides a preferred solution in the first aspect, wherein the high-voltage discharge module also includes a discharge cavity, and a first electrode and a second electrode arranged opposite to each other; the first electrode and the second electrode are arranged in the discharge cavity; the gas delivery module also includes an air intake pipe and an air intake valve for controlling the air intake of the air intake pipe; the discharge cavity and the gas-insulated combination electrical appliance are connected through the air intake pipe; the detection module includes a high-voltage power supply, and the voltage value of the high-voltage power supply is adjustable and displayable; the positive electrode of the high-voltage power supply is connected to the first electrode, and the second electrode is grounded.

[0009] In order to realize the recycling use of the evaluation device and adjust the gas pressure of the insulating gas to be detected in the evaluation device, the present invention provides a preferred solution in the first aspect, wherein the gas delivery module also includes an outlet pipe, a vacuum pump, a gas cylinder and an outlet valve for controlling the outlet of gas from the outlet pipe; the outlet valve is located between the discharge cavity and the vacuum pump; the discharge cavity and the vacuum pump are connected through the outlet pipe; and the gas cylinder is connected to the discharge cavity through an inlet pipe.

[0010] In order to improve the safety of the evaluation device, the present invention provides a preferred solution in the first aspect, wherein the detection module includes a detection circuit and an indication circuit; the detection circuit is connected in series with a high-voltage power supply, a coil part of a normally closed electromagnetic relay, a switch part of a normally open relay, an ammeter, a first electrode and a second electrode; the indication circuit is connected in series with an AC power supply, a signal light, a switch part of a normally closed electromagnetic relay and a coil part of a normally open relay.

[0011] In order to easily obtain the air pressure value of the insulating gas to be detected in the evaluation device, the present invention provides a preferred solution in the first aspect, and the high-voltage discharge module and / or the gas delivery module is provided with a barometer; the barometer is used to measure the air pressure value in the high-voltage discharge module.

[0012] In a second aspect, the present invention provides a method for evaluating the insulation state of an insulating gas, which is based on the above-mentioned evaluation device and includes: S10 presetting a vacuum state in a high-voltage discharge module; S20 obtaining the insulating gas in the gas-insulated combination electrical appliance through a gas delivery module and delivering it to the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value; S30 electrically breaking down the insulating gas in the high-voltage discharge module through a detection module to discharge, and when the discharge current reaches a set current peak, obtaining a discharge voltage value; S40 evaluating the insulation performance of the insulating gas according to the discharge voltage value.

[0013] In order to realize the recycling use of the evaluation device, the present invention provides another insulating gas insulation status evaluation method in the second aspect, including: S11 cleaning the high-voltage discharge module and exhausting it to vacuum; S20 obtaining the insulating gas in the gas-insulated combination electrical appliance through the gas delivery module and delivering it to the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value; S30 electrically breaking down the insulating gas in the high-voltage discharge module through the detection module to discharge, and when the discharge current reaches the set current peak value, a discharge voltage value is obtained; S40 evaluating the insulation performance of the insulating gas according to the discharge voltage value; step S11 is before step S20 and / or after step S40.

[0014] In order to enable the evaluation device to adapt to the easy-to-breakdown gas pressure values ​​of different insulating gases, the present invention provides another insulating gas insulation status evaluation method in the second aspect, including: S11 cleaning the high-voltage discharge module and exhausting it to vacuum; S21 obtaining the insulating gas in the gas-insulated combination electrical appliance through the gas delivery module and delivering it to the high-voltage discharge module; S22 regulating the pressure of the insulating gas in the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set pressure value; S30 electrically breaking down the insulating gas in the high-voltage discharge module through the detection module to discharge, and when the discharge current reaches the set current peak, obtaining the discharge voltage value; S40 evaluating the insulation performance of the insulating gas according to the discharge voltage value; step S11 is before step S21 and / or after step S40.

[0015] In order to enable the evaluation device to simply evaluate the insulation performance of the insulating gas, the present invention provides a preferred solution in the second aspect, setting the gas pressure value in the range of 100-500 Pa and setting the current peak value to be above 100 mA.

[0016] Compared with the prior art, the above technical solution has the following advantages:

[0017] (1) The low-pressure discharge process is used to evaluate the insulation state of the insulating gas, which reduces the gas discharge voltage and improves safety. The insulating gas insulation state evaluation device is set up at the high-voltage electrical equipment site to safely, simply and efficiently evaluate the insulation performance of the insulating gas.

[0018] (2) An electromagnetic relay is used to detect the insulation status of the insulating gas. When the gas discharges, the main circuit power supply can be quickly cut off to ensure the safety of the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 A schematic structural diagram of an insulating gas insulation state assessment device provided by a specific embodiment of the present invention;

[0021] Figure 2 A flowchart of a method for evaluating the insulation state of an insulating gas provided by a specific embodiment of the present invention;

[0022] Figure 3 A schematic structural diagram of an insulating gas insulation state assessment device provided by another specific embodiment of the present invention;

[0023] Figure 4 A flowchart of a method for evaluating the insulation state of an insulating gas provided by another specific embodiment of the present invention;

[0024] Figure 5 A flowchart of an insulating gas insulation state assessment method provided by another specific embodiment of the present invention.

[0025] The accompanying drawings are marked as follows: high-voltage discharge module 10, discharge chamber 11, first electrode 12, second electrode 13, insulating bracket 14, gas delivery module 20, air inlet pipe 21, air inlet valve 22, barometer 23, air outlet valve 24, vacuum pump 25, air outlet pipe 26, gas cylinder 27, detection module 30, high-voltage power supply 31, normally open electromagnetic relay 32, normally closed electromagnetic relay 33, ammeter 34, AC power supply 35, signal light 36. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Embodiment 1

[0028] refer to Figure 1 , this embodiment provides an insulating gas insulation state assessment device, which is mainly composed of a high-voltage discharge module 10, a gas delivery module 20 and a detection module 30. One end of the gas delivery module 20 is connected to the high-voltage discharge module 10, and the other end is connected to the gas-insulated combined electrical appliance, which is used to obtain the insulating gas in the gas-insulated combined electrical appliance and deliver it to the high-voltage discharge module 10; the gas pressure of the insulating gas in the high-voltage discharge module 10 is lower than the gas pressure in the gas-insulated combined electrical appliance; the detection module 30 supplies power to the high-voltage discharge module 10, which is used to break down the insulating gas and form a closed loop with the detection module 30 to obtain the discharge voltage value. More specifically, the high-voltage discharge module 10 is mainly composed of the following parts: a discharge cavity 11, an insulating bracket 14, and a first electrode 12 and a second electrode 13 arranged oppositely. The first electrode 12 and the second electrode 13 are arranged in the discharge cavity 11 through the insulating bracket 14. The gas delivery module 20 is mainly composed of an air intake pipe 21, an air intake valve 22 for controlling the air intake of the air intake pipe 21, and a barometer 23 arranged on the air intake pipe 21. The barometer 23 is used to measure the air pressure in the discharge cavity 11. The discharge cavity 11 and the gas-insulated combined electrical appliance are connected through the air inlet pipe 21. The detection module 30 mainly consists of a high-voltage power supply 31 and an ammeter 34. The voltage value of the high-voltage power supply 31 is adjustable and can be displayed; the positive electrode of the high-voltage power supply 31 is connected to the first electrode 12, and the second electrode 13 is grounded; the positive electrode of the high-voltage power supply 31 is connected to the first electrode 12, and the second electrode 13 is grounded; the ammeter 34, the first electrode 12, the second electrode 13 and the high-voltage power supply 31 are connected in series to form a circuit.

[0029] refer to Figure 2 This embodiment provides an insulating gas insulation state evaluation method, which is based on the above evaluation device and is mainly implemented through the following steps:

[0030] S10 presets the high voltage discharge module to be in a vacuum state;

[0031] S20 obtains the insulating gas in the gas-insulated combination electrical appliance through the gas delivery module and delivers it to the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value;

[0032] S30 discharges the insulating gas in the high-voltage discharge module by means of electrical breakdown of the detection module, and obtains the discharge voltage value when the discharge current reaches the set current peak value;

[0033] S40 evaluates the insulation performance of the insulation gas according to the discharge voltage value.

[0034] Taking the insulating gas filled with the gas insulated switchgear (GIS equipment) as sulfur hexafluoride nitrogen mixed gas (SF6 / N2) as an example, the specific working process of the above-mentioned evaluation device is as follows: before starting the evaluation, the discharge chamber 11 is in a preset vacuum state. When starting the evaluation, first connect the air inlet pipe 21 on the evaluation device to the gas insulated switchgear, and open the air inlet valve 22; the insulating gas flows from the high-voltage gas insulated switchgear to the vacuum discharge chamber 11 through the air inlet pipe 21; when the value of the barometer 23 on the discharge chamber 11 rises to 100-500pa, close the air inlet valve 22. Then, the high-voltage power supply 31 supplies power to the first electrode 12, inducing the discharge of the sulfur hexafluoride nitrogen mixed gas in the discharge chamber 11 until the peak value of the ammeter 34 reaches more than 100mA, and the voltage value of the high-voltage power supply 31 at this time is recorded and the high-voltage power supply 31 is turned off. Finally, if the voltage value is not less than 8kV, the SF6 / N2 insulation is in good condition; if the voltage value is 5-8kV, it indicates that the performance of the insulating gas has declined; if the voltage value is less than 5kV, it indicates that the insulating gas has seriously deteriorated and needs to be replaced in time.

[0035] The insulating gas insulation state evaluation device and method of this embodiment use a low-pressure discharge process to evaluate the insulation state of the insulating gas, reduce the gas discharge voltage, improve safety, and realize the installation of the insulating gas insulation state evaluation device at the high-voltage electrical equipment site to safely, simply and efficiently evaluate the insulation performance of the insulating gas.

[0036] Embodiment 2

[0037] refer to Figure 3 On the basis of the evaluation device of the first embodiment, the gas delivery module 20 in the insulating gas insulation state evaluation device of this embodiment is provided with an outlet pipe 26, a vacuum pump 25, a gas cylinder 27 and an outlet valve 24 for controlling the outlet of the outlet pipe 26; the outlet valve 24 is located between the discharge cavity 11 and the vacuum pump 25; the discharge cavity 11 and the vacuum pump 25 are connected through the outlet pipe 26; the gas cylinder 27 is connected with the discharge cavity 11 through the inlet pipe 21; the pressure gauge 23 on the discharge cavity 11 is added to the outlet pipe 26, and is located between the outlet valve 24 and the discharge cavity 11. The detection module 30 also includes a detection circuit, an ammeter 34 and a normally open electromagnetic relay 32 for controlling the switch of the detection circuit; the normally open electromagnetic relay 32, the ammeter 34, the first electrode 12, the second electrode 13 and the high voltage power supply 31 are connected in series to form a main circuit; the detection circuit is composed of a normally closed electromagnetic relay 33, a signal lamp 36 and an AC power supply 35 connected in series; the normally closed electromagnetic relay 33 controls the switch of the main circuit.

[0038] refer to Figure 4 Based on the evaluation device of this embodiment, a method for evaluating the insulation state of insulating gas is provided, which is mainly implemented by the following steps:

[0039] S11: cleaning the high-voltage discharge module and exhausting it to a vacuum state; this step S11 may be arranged before step S20 or after step S40;

[0040] S20 obtains the insulating gas in the gas-insulated combination electrical appliance through the gas delivery module and delivers it to the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value;

[0041] S30 discharges the insulating gas in the high-voltage discharge module by means of electrical breakdown of the detection module, and obtains the discharge voltage value when the discharge current reaches the set current peak value;

[0042] S40 evaluates the insulation performance of the insulation gas according to the discharge voltage value.

[0043] Please refer to Figure 5 In a more preferred embodiment, a voltage regulation step may be introduced. The insulating gas insulation state assessment method provided in this embodiment is mainly implemented by the following steps:

[0044] S11: cleaning the high-voltage discharge module and exhausting it to a vacuum state; this step S11 may be arranged before step S20 or after step S40;

[0045] S21 obtains the insulating gas in the gas-insulated switchgear through the gas delivery module and delivers it to the high-voltage discharge module;

[0046] S22 adjusts the pressure of the insulating gas in the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value;

[0047] S30 discharges the insulating gas in the high-voltage discharge module by means of electrical breakdown of the detection module, and obtains the discharge voltage value when the discharge current reaches the set current peak value;

[0048] S40 evaluates the insulation performance of the insulation gas according to the discharge voltage value.

[0049] Taking the insulating gas filled with sulfur hexafluoride and nitrogen mixed gas (SF6 / N2) as an example, the specific working process of the above evaluation device is as follows:

[0050] Before starting the evaluation, first connect the air inlet pipe 21 to the gas cylinder 27, then open the air inlet valve 22, and then use the dry gas in the gas cylinder 27 to clean the discharge cavity 11, then open the air outlet valve 24, and then use the vacuum pump 25 to evacuate the gas in the discharge cavity 11, and finally when the air pressure value of the barometer 23 is 10-30Pa, close the air inlet valve 22 and the air outlet valve 24; repeat the above operation several times.

[0051] When starting the evaluation, first connect the air inlet pipe 21 on the evaluation device to the gas-insulated combined electrical appliance, and open the air inlet valve 22; the insulating gas flows from the high-voltage gas-insulated combined electrical appliance to the discharge cavity 11 through the air inlet pipe 21; when the value of the barometer 23 rises to 100-500 Pa, close the air inlet valve 22. Then, open the air outlet valve 24; use the vacuum pump 25 to extract part of the insulating cavity in the discharge cavity 11 through the air outlet pipe 26, and then close the air outlet valve 24 to adjust the air pressure in the discharge cavity 11 and stabilize it at 100-500 Pa. Then the high-voltage power supply 31 supplies power to the first electrode 12, inducing the discharge of the sulfur hexafluoride nitrogen mixed gas in the discharge cavity 11; until the peak value of the ammeter 34 reaches more than 100mA, the normally open electromagnetic relay 32 starts to work; then the detection circuit is turned on, and the light bulb of the detection circuit lights up, indicating that the discharge cavity 11 induces the discharge of the sulfur hexafluoride nitrogen mixed gas; then the normally closed electromagnetic relay 33 works, disconnecting the main circuit; record the voltage value of the high-voltage power supply 31 at this time. Finally, if the voltage value is not less than 8kV, the SF6 / N2 insulation state is good; if the voltage value is 5-8kV, it indicates that the performance of the insulating gas has decreased; if the voltage value is less than 5kV, it indicates that the insulating gas has seriously deteriorated and needs to be replaced in time.

[0052] After the evaluation is completed, first connect the air inlet pipe 21 to the gas cylinder 27, then open the air inlet valve 22, and then use the dry gas in the gas cylinder 27 to clean the discharge cavity 11, then open the air outlet valve 24, and then use the vacuum pump 25 to evacuate the gas in the discharge cavity 11, and finally when the air pressure value of the barometer 23 is 10-30Pa, close the air inlet valve 22 and the air outlet valve 24; repeat the above operation several times.

[0053] The use of a vacuum pump 25 and a gas cylinder 27 to clean the evaluation device can keep the internal evaluation environment of the evaluation device in a stable and good state, which is beneficial to the accuracy of the evaluation and the cyclic evaluation; at the same time, the vacuum pump 25 can adjust the air pressure value in the evaluation device to the easy-to-breakdown pressure value of different insulating gases, which is beneficial for the evaluation device to induce insulating gas discharge at a lower voltage, thereby improving safety; an electromagnetic relay is used to detect the insulation state of the insulating gas, and the main circuit power supply can be quickly cut off when the gas discharges, thereby ensuring the safety of the operator; the insulating gas insulation state evaluation device is set up at the high-voltage electrical equipment site, and the insulation performance of the insulating gas is evaluated safely, simply and efficiently.

[0054] Each embodiment in this specification focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other.

[0055] The above is a detailed introduction to an insulating gas insulation state assessment device and method provided by the present application. This article uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. An insulating gas insulation state assessment device, characterized in that: The invention comprises a high-voltage discharge module (10), a gas delivery module (20) and a detection module (30); one end of the gas delivery module (20) is connected to the high-voltage discharge module (10), and the other end is connected to a gas-insulated combined electrical appliance, and is used to obtain insulating gas in the gas-insulated combined electrical appliance and deliver it to the high-voltage discharge module (10); the gas pressure of the insulating gas in the high-voltage discharge module (10) is lower than the gas pressure in the gas-insulated combined electrical appliance; the detection module (30) supplies power to the high-voltage discharge module (10) and is used to break through the insulating gas to form a closed loop with the detection module (30) to obtain a discharge voltage value.

2. The insulating gas insulation state evaluation device according to claim 1, characterized in that: The high-voltage discharge module (10) comprises a discharge cavity (11), and a first electrode (12) and a second electrode (13) arranged opposite to each other; the first electrode (12) and the second electrode (13) are arranged in the discharge cavity (11); the gas delivery module (20) comprises an air intake pipe (21) and an air intake valve (22) for controlling air intake of the air intake pipe (21); the discharge cavity (11) and the gas-insulated combined electrical appliance are connected via the air intake pipe (21); the detection module (30) comprises a high-voltage power supply (31), the voltage value of the high-voltage power supply (31) is adjustable and displayable; the positive electrode of the high-voltage power supply (31) is connected to the first electrode (12), and the second electrode (13) is grounded.

3. The insulating gas insulation state evaluation device according to claim 2, characterized in that: The high-voltage discharge module (10) further comprises an insulating support (14); the first electrode (12) and / or the second electrode (13) are arranged in the discharge cavity (11) via the insulating support (14).

4. The insulating gas insulation state evaluation device according to claim 2, characterized in that: The gas delivery module (20) further comprises an outlet pipe (26), a vacuum pump (25), a gas cylinder (27), and an outlet valve (24) for controlling the outlet of gas from the outlet pipe (26); the outlet valve (24) is located between the discharge cavity (11) and the vacuum pump (25); the discharge cavity (11) and the vacuum pump (25) are in communication via the outlet pipe (26); and the gas cylinder (27) is in communication with the discharge cavity (11) via the inlet pipe (21).

5. The insulating gas insulation state evaluation device according to claim 2, characterized in that: The detection module (30) comprises a detection circuit and an indication circuit; the detection circuit is connected in series with the high-voltage power supply (31), the coil part of the normally closed electromagnetic relay (33), the switch part of the normally open relay (32), an ammeter (34), a first electrode (12) and a second electrode (13); the indication circuit is connected in series with an AC power supply (35), a signal light (36), the switch part of the normally closed electromagnetic relay (33) and the coil part of the normally open relay (32).

6. The insulating gas insulation state evaluation device according to claim 1, characterized in that: The high-voltage discharge module (10) and / or the gas delivery module (20) is provided with a barometer (23); the barometer (23) is used to measure the air pressure value in the high-voltage discharge module (10).

7. A method for evaluating the insulation state of insulating gas, based on the evaluation device according to any one of claims 1 to 6, characterized in that: include: S10 presets the high voltage discharge module to be in a vacuum state; S20 obtains the insulating gas in the gas-insulated combination electrical appliance through the gas delivery module and delivers it to the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value; S30 discharges the insulating gas in the high-voltage discharge module by means of electrical breakdown of the detection module, and obtains the discharge voltage value when the discharge current reaches the set current peak value; S40 evaluates the insulation performance of the insulation gas according to the discharge voltage value.

8. An insulating gas insulation state evaluation method, based on the evaluation device according to any one of claims 1 to 6, characterized in that: include: S11 cleans the high-voltage discharge module and exhausts it to vacuum; S20 obtains the insulating gas in the gas-insulated combination electrical appliance through the gas delivery module and delivers it to the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value; S30 discharges the insulating gas in the high-voltage discharge module by means of electrical breakdown of the detection module, and obtains the discharge voltage value when the discharge current reaches the set current peak value; S40 evaluates the insulation performance of the insulating gas based on the discharge voltage value; Step S11 is before step S20 and / or after step S40.

9. An insulating gas insulation state evaluation method, based on the evaluation device according to any one of claims 1 to 6, characterized in that: include: S11 cleans the high-voltage discharge module and exhausts it to vacuum; S21 obtains the insulating gas in the gas-insulated switchgear through the gas delivery module and delivers it to the high-voltage discharge module; S22 adjusts the pressure of the insulating gas in the high-voltage discharge module until the gas pressure in the high-voltage discharge module reaches a set gas pressure value; S30 discharges the insulating gas in the high-voltage discharge module by means of electrical breakdown of the detection module, and obtains the discharge voltage value when the discharge current reaches the set current peak value; S40 evaluates the insulation performance of the insulating gas based on the discharge voltage value; Step S11 is before step S21 and / or after step S40 .

10. The insulating gas insulation state evaluation method according to claim 7, 8 or 9, characterized in that: The set air pressure value ranges from 100-500 Pa, and the set current peak value is above 100 mA.

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