Gas taking device and method for gas collecting box of gas relay

Abstract

The invention relates to a gas taking device and method for a gas collecting box of a gas relay, the gas taking device for the gas collecting box of the gas relay comprises the gas collecting box, a sealing oil tank and an oil drain pump with a forward and reverse rotation function, the top of the gas collecting box is connected with a gas taking valve and an air inlet valve capable of being communicated with the gas relay, and the gas collecting box is further connected with an oil drain valve. The oil drain valve is communicated with the sealing oil tank through an oil drain pump, a gas sensor used for detecting the gas content is arranged in the gas collecting box, and the gas sensor and the oil drain pump are both electrically connected with a controller. According to the gas taking device and method of the gas collecting box of the gas relay, the problem that gas in a transformer is difficult to enter the gas collecting box when gas generated by decomposition of an oil medium is less in the existing gas taking device of the gas collecting box is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power voltage equipment, and in particular to a gas extraction device and method for a gas collecting box of a gas relay. Background Art

[0002] Gas protection is a non-electrical protection measure that reflects internal short-circuit faults in transformers. When a short circuit occurs within the transformer, the oil medium decomposes and produces gas. When this gas accumulates on the top of the gas relay, it generates pressure, triggering an alarm and initiating a minor gas protection. A major fault causes a rapid surge of oil, impacting the gas relay, opening the control circuit and triggering a major gas protection.

[0003] When a transformer triggers a gas protection action, whether heavy or light, it generates gas. Since the gas box is filled with oil, once the oil is drained, the gas will flow from the transformer through the gas relay and into the gas box. Therefore, by observing the presence of gas inside the gas relay and sampling and analyzing the gas collected by the gas box, staff can determine the authenticity of the fault and identify whether it is a misoperation of the protection. However, when the gas generated by the decomposition of the oil is relatively small, the air pressure in the conduit between the gas relay and the gas box is very low, possibly far below atmospheric pressure. At this point, even if the oil drain port at the bottom of the gas box is opened, the oil will not fall due to gravity. Instead, it will be sucked by the pressure difference between the conduit and the atmosphere, preventing the gas in the transformer from entering the gas box. Summary of the Invention

[0004] The main purpose of the present invention is to propose a gas collecting box gas extraction device and method for a gas relay, aiming to solve the problem of existing gas collecting box gas extraction equipment that the gas in the transformer is difficult to enter the gas collecting box when the gas generated by the decomposition of the oil medium is small.

[0005] To achieve the above-mentioned objectives, the present invention proposes a gas collecting box gas extraction device for a gas relay, comprising a gas collecting box, a sealed oil tank and an oil drain pump with forward and reverse functions. The top of the gas collecting box is connected to an air extraction valve and an air intake valve that can be connected to the gas relay. The gas collecting box is also connected to an oil drain valve, and the oil drain valve and the sealed oil tank are connected through an oil drain pump. A gas sensor for detecting gas content is provided in the gas collecting box, and the gas sensor and the oil drain pump are both electrically connected to a controller.

[0006] According to some embodiments of the present invention, a three-way joint is further included, through which the oil discharge pump and the sealed oil tank are connected. A pressure gauge for detecting oil pressure is connected to the three-way joint, and the pressure gauge is electrically connected to the controller.

[0007] According to some embodiments of the present invention, a first solenoid valve is further included, and the oil drain valve and the oil drain pump are connected through the first solenoid valve. The valve of the first solenoid valve is connected to a stepper motor drive so that the stepper motor controls the opening size of the valve, and the stepper motor is electrically connected to the controller.

[0008] According to some embodiments of the present invention, a second solenoid valve is further included for connecting to an external oil storage container. An oil inlet pipe and an oil outlet pipe are connected to the sealed oil tank. The second solenoid valve is connected to the sealed oil tank through the oil inlet pipe. The oil drain pump is connected to the sealed oil tank through the oil outlet pipe. The top of the sealed oil tank is connected to an exhaust valve.

[0009] According to some embodiments of the present invention, the oil inlet pipe and the oil outlet pipe both extend into the sealed oil tank and are arranged close to the bottom of the sealed oil tank.

[0010] In addition, the present invention further provides a gas extraction method for a gas collecting box of a gas relay, based on any one of the gas extraction devices for a gas collecting box of a gas relay described above, the gas extraction method comprises the following steps:

[0011] Open the air intake valve and the oil drain valve after receiving the alarm signal;

[0012] Determine the operating power of the oil drain pump according to the type of transformer gas protection action;

[0013] Controlling the oil drain pump to rotate forward according to the operating power, so that the oil medium in the gas collecting box flows through the oil drain pump into the sealed oil tank, so that the gas enters the gas collecting box through the air inlet valve;

[0014] After the gas content in the gas collecting box detected by the gas sensor reaches a preset content, the gas inlet valve is closed and the gas outlet valve is opened;

[0015] Controlling the oil drain pump to reversely run at the original operating power, so that the oil medium in the sealed oil tank flows through the oil drain pump into the gas collecting box, so as to press the gas out from the gas extraction valve;

[0016] After detecting that the air collecting box is full of oil medium, the air intake valve and the oil discharge valve are closed and the oil discharge pump is controlled to stop running.

[0017] According to some embodiments of the present invention, after controlling the oil discharge pump to rotate forward, the method further includes:

[0018] Determining the dynamic balance range of the oil pressure in the pipeline between the oil drain pump and the sealed oil tank according to the type of transformer gas protection action;

[0019] Obtaining the current oil pressure value of the pipeline;

[0020] The valve opening of the first solenoid valve is adjusted according to the oil pressure dynamic balance range and the current oil pressure value, so that the current oil pressure value is within the oil pressure dynamic balance range.

[0021] According to some embodiments of the present invention, adjusting the valve opening of the first solenoid valve according to the oil pressure dynamic balance range and the current oil pressure value so that the current oil pressure value is within the oil pressure dynamic balance range includes:

[0022] comparing the current oil pressure value with the oil pressure dynamic balance range;

[0023] When the current oil pressure value is less than the minimum value of the oil pressure dynamic balance range, controlling the stepping motor to reduce the valve opening until the current oil pressure value is within the oil pressure dynamic balance range;

[0024] When the current oil pressure value is greater than the maximum value of the oil pressure dynamic balance range, the stepping motor is controlled to increase the valve opening until the current oil pressure value is within the oil pressure dynamic balance range.

[0025] According to some embodiments of the present invention, before opening the air intake valve and the oil drain valve, the method further includes:

[0026] Open the oil drain valve and control the oil drain pump to run forward, so that the oil medium in the air collecting box flows through the oil drain pump into the sealed oil tank, so that the air in all pipes between the oil drain valve and the sealed oil tank is discharged into the sealed oil tank;

[0027] After observing that the oil medium level in the sealed oil tank is higher than the pipe openings of the oil inlet pipe and the oil outlet pipe, the second solenoid valve is opened and the oil discharge pump is controlled to reversely run, so that the oil medium in the external oil storage container enters the sealed oil tank;

[0028] After observing that the oil medium flows out of the exhaust valve on the top of the sealed oil tank, the oil discharge pump is controlled to stop running and the oil discharge valve and the exhaust valve are closed.

[0029] According to some embodiments of the present invention, after controlling the oil drain pump to operate in reverse, the method further includes:

[0030] Obtaining a current oil pressure value of the pipeline between the oil discharge pump and the sealed oil tank;

[0031] When the current oil pressure value is less than the minimum value of the preset oil pressure range, closing the oil drain valve and opening the second solenoid valve;

[0032] After detecting that the current oil pressure value is within the preset oil pressure range, the oil drain valve is opened.

[0033] The present invention has at least the following beneficial effects:

[0034] In the present invention, after the gas protection action of the transformer occurs, the gas decomposed from the oil medium inside the transformer gathers in the gas relay. At this time, the air inlet valve and the oil drain valve are opened, and the oil drain pump runs in the forward direction to drive the oil medium in the gas collecting box to be discharged from the oil drain valve into the sealed oil tank. Since the gas collecting box is almost in a vacuum state after the oil medium is discharged, the gas in the gas relay enters the gas collecting box from the air inlet valve under the action of air pressure. When the gas sensor in the gas collecting box detects that the gas content in the gas collecting box reaches the required amount, the air inlet valve is closed and the air extraction valve is opened. The oil drain pump runs in the reverse direction to drive the oil medium in the sealed oil tank to be discharged into the gas collecting box until the oil medium fills the gas collecting box, so as to push the gas in the gas collecting box out from the air extraction valve for subsequent gas sampling and analysis. The present invention realizes the extraction and injection of the oil medium in the gas collecting box by the forward and reverse rotation of the oil drain pump, so that even if there is less gas in the transformer, it can enter the gas collecting box under the action of air pressure and be output to the subsequent sampling and analysis process after the gas collection is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic structural diagram of a gas collecting box gas extraction device for a gas relay provided in an embodiment of the present invention;

[0037] Figure 2 This is a flow chart of a first embodiment of a method for extracting gas from a gas collecting box of a gas relay according to the present invention;

[0038] Figure 3 This is a schematic flow chart of a second embodiment of the gas extraction method of the present invention;

[0039] Figure 4 This is a schematic flow chart of a third embodiment of the gas extraction method of the present invention;

[0040] Figure 5 This is a schematic flow chart of a fourth embodiment of the gas extraction method of the present invention;

[0041] Figure 6 Schematic diagram of the flow chart of the fifth embodiment of the gas extraction method of the present invention.

[0042] Description of reference numerals:

[0043] 100-Gas relay gas collecting box gas extraction device; 1-Gas collecting box; 11-Gas extraction valve; 12-Air inlet valve; 13-Oil drain valve; 14-Observation window; 2-Sealed oil tank; 21-Oil inlet pipe; 22-Oil outlet pipe; 3-Oil drain pump; 4-Tee connector; 5-Pressure gauge; 6-First solenoid valve; 7-Second solenoid valve; 8-Exhaust valve; 200-External oil storage container. DETAILED DESCRIPTION

[0044] The following is a clear and complete description of 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 making any creative efforts are within the scope of protection of the present invention.

[0045] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0046] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] The present invention provides a gas collecting box gas extraction device and method for a gas relay. Figures 1 to 6 The present invention provides a specific embodiment of a gas extraction device and method for a gas collecting box of a gas relay.

[0048] like Figure 1As shown, an embodiment of the present invention provides a gas collecting box gas extraction device 100 for a gas relay, comprising a gas collecting box 1, a sealed oil tank 2 and an oil drain pump 3 with forward and reverse functions. The top of the gas collecting box 1 is connected to an air extraction valve 11 and an air intake valve 12 that can be connected to the gas relay. The gas collecting box 1 is also connected to an oil drain valve 13, and the oil drain valve 13 and the sealed oil tank 2 are connected through the oil drain pump 3. A gas sensor for detecting gas content is provided in the gas collecting box 1, and the gas sensor and the oil drain pump 3 are both electrically connected to a controller.

[0049] In the present invention, after the gas protection action of the transformer occurs, the gas decomposed by the oil medium inside the transformer gathers in the gas relay. At this time, the air inlet valve 12 and the oil drain valve 13 are opened, and the oil drain pump 3 runs in the forward direction, driving the oil medium in the gas collecting box 1 to be discharged from the oil drain valve 13 into the sealed oil tank 2. Since the gas collecting box 1 is almost in a vacuum state after the oil medium is discharged, the gas in the gas relay enters the gas collecting box 1 from the air inlet valve 12 under the action of air pressure. When the gas sensor in the gas collecting box 1 detects that the gas content in the gas collecting box 1 reaches the required amount, the air inlet valve 12 is closed and the air extraction valve 11 is opened. The oil drain pump 3 runs in the reverse direction, driving the oil medium in the sealed oil tank 2 to be discharged into the gas collecting box 1 until the oil medium fills the gas collecting box 1, so as to push the gas in the gas collecting box 1 out from the air extraction valve 11 for subsequent gas sampling and analysis. The present invention realizes the extraction and injection of the oil medium in the gas collecting box 1 by the forward and reverse rotation of the oil drain pump 3, so that even if there is less gas in the transformer, it can enter the gas collecting box 1 under the action of gas pressure and be output to the subsequent sampling and analysis process after the gas collection is completed.

[0050] Specifically, in some embodiments, Figure 1 As shown, the gas collecting box 1 is provided with an observation window 14. When a large amount of gas enters the gas collecting box 1, bubbles will appear on the surface of the remaining oil medium in the gas collecting box 1. When the gas sensor fails, this can be used to roughly determine whether the amount of gas collected in the gas collecting box 1 is sufficient.

[0051] In order to facilitate the adjustment of the oil pressure in the pipeline, in some embodiments, as Figure 1As shown, the gas relay gas collecting box gas extraction device 100 also includes a three-way joint 4, the oil drain pump 3 and the sealed oil tank 2 are connected via the three-way joint 4, and a pressure gauge 5 for detecting oil pressure is connected to the three-way joint 4, and the pressure gauge 5 is electrically connected to the controller. In this arrangement, the oil pressure of the pipeline between the oil drain pump 3 and the sealed oil tank 2 is detected in real time by the pressure gauge 5. If the oil pressure is too low, it means that the oil medium in the sealed oil tank 2 is insufficient. If the oil drain pump 3 continues to operate, air may enter the pipeline and be discharged into the gas collecting box 1 from the oil drain valve 13, thereby causing the gas in the gas collecting box 1 to be contaminated, affecting the subsequent gas sampling and analysis results. If the oil pressure is too high, it may cause the pipeline to rupture. Therefore, the pipeline oil pressure is adjusted in real time according to the oil pressure value detected by the pressure gauge 5 to ensure the normal operation of the device.

[0052] When the oil flow velocity and the pipeline oil pressure are in a dynamic equilibrium state, the flow resistance of the oil medium can be reduced, and the device can be operated efficiently and stably. In some embodiments, such as Figure 1 As shown, the gas relay gas collecting box gas extraction device 100 also includes a first solenoid valve 6, and the oil drain valve 13 and the oil drain pump 3 are connected through the first solenoid valve 6. The valve of the first solenoid valve 6 is connected to the stepper motor drive so that the stepper motor controls the opening size of the valve, and the stepper motor is electrically connected to the controller. In this arrangement, since the dynamic balance range of oil pressure is related to the volume of gas accumulated in the gas relay, and the gas volume is directly related to the type of transformer gas protection action, the dynamic balance range of oil pressure corresponding to the heavy gas protection action and the light gas protection action is different. When the controller receives the alarm signal, it can determine the type of transformer gas protection action according to the content of the message, and then determine the dynamic balance range of oil pressure. Then, after obtaining the current oil pressure value of the pipeline through the pressure gauge 5, if the current oil pressure value is greater than the maximum value of the dynamic balance range of oil pressure, the valve opening of the first solenoid valve 6 is increased by controlling the stepper motor to reduce the oil flow rate, thereby reducing the oil pressure in the pipeline. If the current oil pressure value is less than the minimum value of the dynamic balance range of oil pressure, the valve opening of the first solenoid valve 6 is reduced by controlling the stepper motor to increase the oil flow rate, thereby increasing the oil pressure in the pipeline, thereby adjusting the pipeline oil pressure to be within the dynamic balance range of oil pressure.

[0053] Furthermore, in some embodiments, Figure 1As shown, the gas relay gas collecting box air extraction device 100 also includes a second solenoid valve 7 for communicating with an external oil storage container 200. The sealed oil tank 2 is connected to an oil inlet pipe 21 and an oil outlet pipe 22. The second solenoid valve 7 is connected to the sealed oil tank 2 via the oil inlet pipe 21, and the oil drain pump 3 is connected to the sealed oil tank 2 via the oil outlet pipe 22. The top of the sealed oil tank 2 is connected to an exhaust valve 8. With this arrangement, when the pressure gauge 5 detects that the oil pressure in the pipeline between the oil drain pump 3 and the sealed oil tank 2 is too low in real time, it indicates that the oil medium in the sealed oil tank 2 is insufficient. If the oil drain pump 3 continues to operate, air may enter the pipeline. Therefore, by closing the oil drain valve 13 and opening the second solenoid valve 7, the oil medium in the external oil storage container 200 is input into the sealed oil tank 2, thereby increasing the oil pressure in the pipeline. At the same time, the top of the sealed oil tank 2 is connected to the exhaust valve 8. As the oil medium in the sealed oil tank 2 increases, the air in the sealed oil tank 2 can be pushed upward and then discharged from the exhaust valve 8.

[0054] Furthermore, in some embodiments, Figure 1 As shown, the oil inlet pipe 21 and the oil outlet pipe 22 both extend into the sealed oil tank 2 and are disposed near the bottom of the sealed oil tank 2. With this arrangement, since the oil inlet pipe 21 and the oil outlet pipe 22 are both located near the bottom of the sealed oil tank 2, the oil medium in the sealed oil tank 2 only needs to be higher than the pipe openings of the oil inlet pipe 21 and the oil outlet pipe 22 to achieve an oil sealing effect, preventing air from entering the pipe through the oil outlet pipe 22. The oil medium does not need to fill the entire sealed oil tank 2, thereby reducing waste of the oil medium.

[0055] Those skilled in the art will appreciate that the above structure does not limit the gas collecting box gas extraction device 100 of the gas relay, and may include more or fewer components than those described above, or a combination of certain components, or a different arrangement of components.

[0056] like Figure 2 As shown, an embodiment of the present invention provides a method for extracting gas from a gas collecting box 1 of a gas relay, comprising the following steps:

[0057] Step S40: opening the air intake valve 12 and the oil drain valve 13 after receiving the alarm signal.

[0058] It should be noted that when an alarm signal is received, it indicates that the transformer has undergone heavy gas protection action or light gas protection action, and the oil medium in the transformer will decompose to produce gas. Therefore, it is necessary to open the air inlet valve 12 to supply gas to enter the gas collecting box 1. At the same time, since the gas collecting box 1 is already full of oil medium in the initial state and there is no space to accommodate gas, it is necessary to open the oil drain valve 13 to discharge the oil medium.

[0059] Step S50: Determine the operating power of the oil drain pump 3 according to the transformer gas protection action type.

[0060] It should be noted that, when the controller receives the alarm signal, the type of transformer gas protection action can be determined according to the message content.

[0061] It should be noted that when the transformer undergoes heavy gas protection action, more gas is decomposed from the oil medium inside it, while when the transformer undergoes light gas protection action, less gas is decomposed from the oil medium inside it. When the gas applies thrust to the oil medium in the gas collecting box 1, the thrust and the driving force of the oil drain pump 3 work together to discharge the oil medium from the oil drain valve 13. The amount of gas is different, and the thrust applied is also different, so the driving force required for the oil drain pump 3 is also different. Therefore, for different types of gas protection actions, the operating power of the oil drain pump 3 is different.

[0062] It should be noted that when the transformer undergoes heavy gas protection action, the first preset power is used as the operating power of the oil drain pump 3; when the transformer undergoes light gas protection action, the second preset power is used as the operating power of the oil drain pump 3; wherein, the first preset power is less than the second preset power.

[0063] Step S60 : controlling the oil drain pump 3 to rotate forward according to the operating power, so that the oil medium in the gas collecting box 1 flows through the oil drain pump 3 into the sealed oil tank 2 , so that gas enters the gas collecting box 1 through the air inlet valve 12 .

[0064] It should be noted that the oil medium is drawn out of the gas collecting box 1 by the thrust of the gas and the driving force of the oil drain pump 3 , so that the oil medium is temporarily stored in the sealed oil tank 2 .

[0065] Step S100: After the gas content in the gas collecting box 1 detected by the gas sensor reaches a preset content, the gas inlet valve 12 is closed and the gas outlet valve 11 is opened.

[0066] It should be noted that when it is detected that the gas content reaches the preset content, it means that the gas collecting box 1 has collected enough gas. At this time, the air inlet valve 12 is closed and the air extraction valve 11 is opened, so that the gas is output from the air extraction valve 11 to the subsequent gas sampling and analysis process.

[0067] Step S110 : controlling the oil drain pump 3 to reversely run at the original operating power, so that the oil medium in the sealed oil tank 2 flows through the oil drain pump 3 into the gas collecting box 1 to press the gas out from the gas extraction valve 11 .

[0068] It should be noted that, since the air extraction valve 11 is open and the density of the gas is less than that of the oil medium, the oil drainage pump 3 only needs to ensure that it can drive the oil medium into the air collecting box 1. Therefore, the actual operating power required by the oil drainage pump 3 is relatively small. This application chooses to control the reverse operation of the oil drainage pump 3 with the original operating power, so that the operating power during forward and reverse rotation is the same, thereby making the torque output by the motor and the axial and radial loads close during forward and reverse rotation, reducing the sudden change in mechanical stress caused by direction switching, extending the life of bearings, seals and impellers, and when the power is consistent, the forward and reverse switching has less impact on the power grid, reducing the configuration complexity of the inverter or soft starter.

[0069] Step S150: After detecting that the gas collecting box 1 is full of oil medium, the gas intake valve 11 and the oil discharge valve 13 are closed and the oil discharge pump 3 is controlled to stop running.

[0070] It should be noted that the oil medium liquid level in the gas collecting box 1 can be detected by setting a liquid level sensor in the gas collecting box 1. When it is detected that the gas collecting box 1 is full of oil medium, it means that all the gas in the gas collecting box 1 has been output. At this time, the air intake valve 11 and the oil drain valve 13 are closed to prevent the oil medium from entering the air intake valve 11.

[0071] In the present invention, the gas extraction method of the gas relay gas collecting box 1 includes the following steps: opening the air inlet valve 12 and the oil drain valve 13 after receiving an alarm signal; determining the operating power of the oil drain pump 3 according to the transformer gas protection action type; controlling the oil drain pump 3 to run forward according to the operating power, so that the oil medium in the gas collecting box 1 flows through the oil drain pump 3 into the sealed oil tank 2, so that gas can enter the gas collecting box 1 from the air inlet valve 12; after the gas content in the gas collecting box 1 detected by the gas sensor reaches a preset content, closing the air inlet valve 12 and opening the air extraction valve 11; controlling the oil drain pump 3 to run in reverse with the original operating power, so that the oil medium in the sealed oil tank 2 flows through the oil drain pump 3 into the gas collecting box 1, so as to press the gas out from the air extraction valve 11; after detecting that the gas collecting box 1 is full of oil medium, closing the air extraction valve 11 and the oil drain valve 13 and controlling the oil drain pump 3 to stop running. The gas extraction method for the gas collecting box 1 of a gas relay provided by the present invention solves the problem of the existing gas extraction equipment for the gas collecting box 1 that the gas in the transformer is difficult to enter the gas collecting box 1 when the gas generated by the decomposition of the oil medium is small.

[0072] refer to Figure 3 , Figure 3 Schematic diagram of the flow chart of the second embodiment of the gas extraction method of the present invention.

[0073] Based on the first embodiment described above, the gas extraction method of this embodiment further includes, after step S60:

[0074] Step S70: determining the dynamic balance range of the oil pressure in the pipeline between the oil drain pump 3 and the sealed oil tank 2 according to the transformer gas protection action type.

[0075] It should be noted that since the dynamic balance range of oil pressure is related to the volume of gas accumulated in the gas relay, and the gas volume is directly related to the type of transformer gas protection action, the dynamic balance range of oil pressure corresponding to heavy gas protection action and light gas protection action is different.

[0076] Specifically, when a light gas protection action occurs, the volume of gas accumulated in the gas relay is generally 250-350 cm³, while when a heavy gas protection action occurs, the volume of gas accumulated in the gas relay is 2500-3500 cm³.

[0077] Step S80: Acquire the current oil pressure value of the pipeline.

[0078] It should be noted that the current oil pressure value of the pipeline between the oil discharge pump 3 and the sealed oil tank 2 can be detected by the pressure gauge 5 .

[0079] Step S90: adjusting the valve opening of the first solenoid valve 6 according to the oil pressure dynamic balance range and the current oil pressure value, so that the current oil pressure value is within the oil pressure dynamic balance range.

[0080] It should be noted that by adjusting the valve opening of the first solenoid valve 6, the oil flow rate can be adjusted, and then the oil pressure value of the pipeline can be adjusted so that the oil pressure value of the pipeline is within the oil pressure dynamic balance range.

[0081] In this embodiment, the dynamic balance range of the oil pressure in the pipeline between the oil drain pump 3 and the sealed oil tank 2 is first determined according to the type of transformer gas protection action, and then the current oil pressure value of the pipeline is obtained. Finally, the valve opening of the first solenoid valve 6 is adjusted according to the dynamic balance range of the oil pressure and the current oil pressure value, thereby adjusting the oil flow rate to adjust the oil pressure value of the pipeline so that the current oil pressure value is within the dynamic balance range of the oil pressure.

[0082] refer to Figure 4 , Figure 4 Schematic diagram of the flow of the third embodiment of the gas extraction method of the present invention.

[0083] Based on the above second embodiment, the gas extraction method of this embodiment includes, in step S90:

[0084] Step S91: Compare the current oil pressure value with the oil pressure dynamic balance range.

[0085] It should be noted that if the current oil pressure value is within the oil pressure dynamic balance range, there is no need to adjust the valve opening of the first solenoid valve 6 .

[0086] Step S92: When the current oil pressure value is less than the minimum value of the oil pressure dynamic balance range, controlling the stepper motor to reduce the valve opening until the current oil pressure value is within the oil pressure dynamic balance range.

[0087] It should be noted that, since the stepper motor is connected to the valve driving connection, the stepper motor can drive the valve to move along the radial direction of the opening of the first solenoid valve 6, thereby adjusting the valve opening.

[0088] Step S93: When the current oil pressure value is greater than the maximum value of the oil pressure dynamic balance range, controlling the stepper motor to increase the valve opening until the current oil pressure value is within the oil pressure dynamic balance range.

[0089] It should be noted that by reducing the valve opening, the oil flow rate can be increased, thereby increasing the oil pressure value of the pipeline, while by increasing the valve opening, the oil flow rate can be reduced, thereby reducing the oil pressure value of the pipeline.

[0090] In this embodiment, the current oil pressure value is compared with the oil pressure dynamic balance range. When the current oil pressure value is less than the minimum value of the oil pressure dynamic balance range, the stepper motor is controlled to reduce the valve opening until the current oil pressure value is within the oil pressure dynamic balance range. When the current oil pressure value is greater than the maximum value of the oil pressure dynamic balance range, the stepper motor is controlled to increase the valve opening until the current oil pressure value is within the oil pressure dynamic balance range.

[0091] refer to Figure 5 , Figure 5 Schematic diagram of the flow chart of the fourth embodiment of the gas extraction method of the present invention.

[0092] Based on the first embodiment described above, the gas extraction method of this embodiment further includes, before step S40:

[0093] Step S10: Open the oil drain valve 13 and control the oil drain pump 3 to run forward, so that the oil medium in the air collecting box 1 flows through the oil drain pump 3 into the sealed oil tank 2, so that the air in all pipes between the oil drain valve 13 and the sealed oil tank 2 is discharged into the sealed oil tank 2.

[0094] It should be noted that after the various components of the gas relay gas collecting box and air extraction device 100 are installed, there is air in the pipeline, and it is necessary to discharge all the air first to avoid contaminating the gas collected by the gas collecting box 1. By extracting a small amount of oil medium from the gas collecting box 1 into the sealed oil tank 2, the air in all the pipelines between the oil drain valve 13 and the sealed oil tank 2 can be discharged into the sealed oil tank 2.

[0095] Step S20: After observing that the oil medium level in the sealed oil tank 2 is higher than the pipe openings of the oil inlet pipe 21 and the oil outlet pipe 22, the second solenoid valve 7 is opened and the oil drain pump 3 is controlled to reversely operate, so that the oil medium in the external oil storage container 200 enters the sealed oil tank 2.

[0096] It should be noted that, when it is observed that the oil medium liquid level in the sealed oil tank 2 is higher than the pipe openings of the oil inlet pipe 21 and the oil outlet pipe 22, it indicates that oil sealing has been achieved in the sealed oil tank 2. At this time, the oil drain pump 3 is controlled to reverse and run, so that the oil medium in the sealed oil tank 2 returns to the air collecting box 1. At the same time, the oil medium in the external oil storage container 200 is extracted into the sealed oil tank 2. During this process, air cannot enter the oil drain pump 3 through the oil outlet pipe 22.

[0097] Step S30: After observing that the oil medium flows out of the exhaust valve 8 at the top of the sealed oil tank 2, the oil discharge pump 3 is controlled to stop running and the oil discharge valve 13 and the exhaust valve 8 are closed.

[0098] It should be noted that when oil medium is observed to flow out of the exhaust valve 8 on the top of the sealed oil tank 2, it means that the air collecting box 1 and the sealed oil tank 2 are both filled with oil medium, and all pipes between the oil drain valve 13 and the sealed oil tank 2 are also filled with oil medium, and there is no air.

[0099] In this embodiment, the oil drain valve 13 is first opened and the oil drain pump 3 is controlled to run forward, so that the oil medium in the gas collecting box 1 flows through the oil drain pump 3 into the sealed oil tank 2, so that the air in all pipes between the oil drain valve 13 and the sealed oil tank 2 is discharged into the sealed oil tank 2, and then after observing that the oil medium liquid level in the sealed oil tank 2 is higher than the pipe openings of the oil inlet pipe 21 and the oil outlet pipe 22, the second solenoid valve 7 is opened and the oil drain pump 3 is controlled to run in reverse, so that the oil medium in the external oil storage container 200 enters the sealed oil tank 2, and finally after observing that the exhaust valve 8 at the top of the sealed oil tank 2 flows out the oil medium, the oil drain pump 3 is controlled to stop running and the oil drain valve 13 and the exhaust valve 8 are closed to realize the discharge of air in all components of the gas collecting box air extraction device 100 of the gas relay.

[0100] refer to Figure 6 , Figure 6Schematic diagram of the flow chart of the fifth embodiment of the gas extraction method of the present invention.

[0101] Based on the first embodiment described above, the gas extraction method of this embodiment further includes, after step S110:

[0102] Step S120: obtaining the current oil pressure value of the pipeline between the oil discharge pump 3 and the sealed oil tank 2.

[0103] Step S130: When the current oil pressure value is less than the minimum value of the preset oil pressure range, the oil drain valve 13 is closed and the second solenoid valve 7 is opened.

[0104] It should be noted that when the current oil pressure value is less than the minimum value of the preset oil pressure range, it means that the oil medium in the sealed oil tank 2 is insufficient. If the oil drain pump 3 continues to run, air may enter the pipeline and be discharged into the gas collecting box 1 from the oil drain valve 13, thereby causing the gas in the gas collecting box 1 to be contaminated, affecting the subsequent gas sampling and analysis results. Therefore, the oil drain valve 13 is closed and the second solenoid valve 7 is in the open state. The oil drain pump 3 operates normally in reverse and can extract the oil medium in the external oil storage container 200 connected to the second solenoid valve 7 into the sealed oil tank 2. At this time, since the oil drain valve 13 is closed, the oil medium cannot enter the gas collecting box 1, causing the oil pressure value of the pipeline to increase.

[0105] Step S140: after detecting that the current oil pressure value is within the preset oil pressure range, opening the oil drain valve 13 .

[0106] It should be noted that, when it is detected that the current oil pressure value is within the preset oil pressure range, the oil drain valve 13 is opened to allow the oil medium to enter the air collecting box 1 to avoid excessive oil pressure that may cause the pipeline to rupture.

[0107] In this embodiment, the current oil pressure value of the pipeline between the oil drain pump 3 and the sealed oil tank 2 is first obtained. When the current oil pressure value is less than the minimum value of the preset oil pressure range, the oil drain valve 13 is closed and the second solenoid valve 7 is opened. After detecting that the current oil pressure value is within the preset oil pressure range, the oil drain valve 13 is opened.

[0108] It should be understood that, although the various steps in the flowchart in the embodiment of the present application are shown in sequence according to the indication of the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless clearly stated herein, the execution of these steps is not strictly limited in order, and they can be performed in other orders. Moreover, at least a portion of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and their execution order is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0109] It should be understood that the above is only an example and does not constitute any limitation to the technical solution of the present invention. In specific applications, those skilled in the art can make settings as needed, and the present invention does not impose any limitation on this.

[0110] It should be noted that the workflow described above is merely illustrative and does not limit the scope of protection of the present invention. In practical applications, technicians in this field can select part or all of it according to actual needs to achieve the purpose of the embodiment scheme, and no limitation is made here.

[0111] In addition, it should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0112] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A gas collecting box gas extraction device for a gas relay, characterized in that: It includes a gas collecting box, a sealed oil tank and an oil drain pump with forward and reverse rotation functions. The top of the gas collecting box is connected to an air extraction valve and an air inlet valve that can be connected to a gas relay. The gas collecting box is also connected to an oil drain valve. The oil drain valve and the sealed oil tank are connected through the oil drain pump. A gas sensor for detecting gas content is provided in the gas collecting box. The gas sensor and the oil drain pump are both electrically connected to a controller.

2. The gas collecting box gas extraction device for a gas relay according to claim 1, characterized in that: It also includes a three-way joint, through which the oil discharge pump and the sealed oil tank are connected. The three-way joint is connected to a pressure gauge for detecting oil pressure, and the pressure gauge is electrically connected to the controller.

3. The gas collecting box gas extraction device for a gas relay according to claim 2, characterized in that: It also includes a first solenoid valve, through which the oil drain valve and the oil drain pump are connected, the valve of the first solenoid valve is connected to a stepper motor drive so that the stepper motor controls the opening size of the valve, and the stepper motor is electrically connected to the controller.

4. The gas collecting box gas extraction device for a gas relay according to claim 2, characterized in that: It also includes a second solenoid valve for connecting to an external oil storage container. The sealed oil tank is connected to an oil inlet pipe and an oil outlet pipe. The second solenoid valve is connected to the sealed oil tank through the oil inlet pipe. The oil drain pump is connected to the sealed oil tank through the oil outlet pipe. The top of the sealed oil tank is connected to an exhaust valve.

5. The gas collecting box gas extraction device for a gas relay according to claim 4, characterized in that: The oil inlet pipe and the oil outlet pipe both extend into the sealed oil tank and are arranged close to the bottom of the sealed oil tank.

6. A method for extracting gas from a gas collecting box of a gas relay, based on the gas extracting device for a gas collecting box of a gas relay according to any one of claims 1 to 5, characterized in that: The following steps are involved: Open the air intake valve and the oil drain valve after receiving the alarm signal; Determine the operating power of the oil drain pump according to the type of transformer gas protection action; Controlling the oil drain pump to rotate forward according to the operating power, so that the oil medium in the gas collecting box flows through the oil drain pump into the sealed oil tank, so that the gas enters the gas collecting box through the air inlet valve; After the gas content in the gas collecting box detected by the gas sensor reaches a preset content, the gas inlet valve is closed and the gas outlet valve is opened; Controlling the oil drain pump to reversely run at the original operating power, so that the oil medium in the sealed oil tank flows through the oil drain pump into the gas collecting box, so as to press the gas out from the gas extraction valve; After detecting that the air collecting box is full of oil medium, the air intake valve and the oil discharge valve are closed and the oil discharge pump is controlled to stop running.

7. The gas extraction method for a gas collecting box of a gas relay according to claim 6, characterized in that: After controlling the oil discharge pump to run forward, it also includes: Determining the dynamic balance range of the oil pressure in the pipeline between the oil drain pump and the sealed oil tank according to the type of transformer gas protection action; Obtaining the current oil pressure value of the pipeline; The valve opening of the first solenoid valve is adjusted according to the oil pressure dynamic balance range and the current oil pressure value, so that the current oil pressure value is within the oil pressure dynamic balance range.

8. The gas extraction method for a gas collecting box of a gas relay according to claim 7, characterized in that: The adjusting the valve opening of the first solenoid valve according to the oil pressure dynamic balance range and the current oil pressure value so that the current oil pressure value is within the oil pressure dynamic balance range includes: comparing the current oil pressure value with the oil pressure dynamic balance range; When the current oil pressure value is less than the minimum value of the oil pressure dynamic balance range, controlling the stepping motor to reduce the valve opening until the current oil pressure value is within the oil pressure dynamic balance range; When the current oil pressure value is greater than the maximum value of the oil pressure dynamic balance range, the stepping motor is controlled to increase the valve opening until the current oil pressure value is within the oil pressure dynamic balance range.

9. The gas extraction method for a gas collecting box of a gas relay according to claim 6, wherein: Before opening the air intake valve and the oil drain valve, the method further comprises: Open the oil drain valve and control the oil drain pump to run forward, so that the oil medium in the air collecting box flows through the oil drain pump into the sealed oil tank, so that the air in all pipes between the oil drain valve and the sealed oil tank is discharged into the sealed oil tank; After observing that the oil medium level in the sealed oil tank is higher than the pipe openings of the oil inlet pipe and the oil outlet pipe, the second solenoid valve is opened and the oil discharge pump is controlled to reversely run, so that the oil medium in the external oil storage container enters the sealed oil tank; After observing that the oil medium flows out of the exhaust valve on the top of the sealed oil tank, the oil discharge pump is controlled to stop running and the oil discharge valve and the exhaust valve are closed.

10. The gas extraction method for a gas collecting box of a gas relay according to claim 6, characterized in that: After controlling the oil discharge pump to reversely operate, the method further includes: Obtaining a current oil pressure value of the pipeline between the oil discharge pump and the sealed oil tank; When the current oil pressure value is less than the minimum value of the preset oil pressure range, closing the oil drain valve and opening the second solenoid valve; After detecting that the current oil pressure value is within the preset oil pressure range, the oil drain valve is opened.

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