An on-line monitoring device and method for oil leakage of large oil-immersed transformer equipment

Abstract

The application discloses a kind of large oil-immersed transformer equipment oil leakage online monitoring device and monitoring method, including the hydraulic sensor of pipeline being arranged between transformer body and oil pillow, fire oil drain pipe on the transformer body is equipped with oil leakage detection sensor;Its monitoring method includes S1: hydraulic sensor is set on datum plane, the height change ΔH of oil in oil pillow is calculated according to the detection value P of hydraulic sensor;S2: whether transformer body, fire oil drain pipe is leaked by the cooperation of oil pillow oil level change and oil leakage detection sensor to judge.Judgment transformer body, fire oil drain pipe whether leak by the cooperation of oil pillow oil level change and oil leakage detection sensor, and whether serious when fire oil drain pipe leaks compared with prior art, the pressure of hydraulic sensor is calculated by the pressure relationship between oil pillow oil pressure, atmospheric pressure, transformer body oil pressure, and the oil level of oil pillow is calculated by the formula of pressure conversion into oil level.Then whether transformer body, fire oil drain pipe is leaked by the cooperation of oil pillow oil level change and oil leakage detection sensor, and whether serious when fire oil drain pipe leaks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of large oil-immersed transformer oil leakage monitoring, and particularly relates to a large oil-immersed transformer equipment oil leakage online monitoring device and a monitoring method. BACKGROUND

[0002] A transformer substation is an important component of a power grid. A main transformer in a high-voltage grade transformer substation is large in size and is mostly an oil-filled device. In particular, in an extra-high voltage and ultra-high voltage AC transformer substation, the weight of the main transformer can reach several hundred tons, and the transformer oil is also more than several dozen tons. With the increase of the use time of the transformer, the transformer will have oil leakage. In the prior art, other devices and multiple sensors need to be installed on the transformer to monitor the oil leakage of the transformer. In this way, many devices are installed, the transformer is greatly modified, and the monitoring cost is high.

[0003] Therefore, it is necessary to provide a large oil-immersed transformer equipment oil leakage online monitoring device to solve the above technical problems through experiments. SUMMARY

[0004] The technical problem to be solved by the present application is to disclose a large oil-immersed transformer equipment oil leakage online monitoring device and a monitoring method to solve the problems of great modification of the transformer and high monitoring cost of the existing monitoring method.

[0005] The technical solution adopted by the present application to solve the technical problem is: a large oil-immersed transformer equipment oil leakage online monitoring device, comprising a hydraulic sensor arranged on a pipeline between a transformer body and an oil pillow, and a leakage detection sensor arranged on a fire-fighting oil discharge pipe of the transformer body.

[0006] Preferably, the device further comprises an on-site data processing module, which is in communication connection with the hydraulic sensor and the leakage detection sensor, respectively.

[0007] Preferably, the device further comprises a mobile terminal, which is connected with the on-site data processing module through a communication module.

[0008] Preferably, the device further comprises a server, which is connected with the on-site data processing module, and the server is connected with a transformer substation monitor.

[0009] Preferably, the device further comprises a production management system, which is connected with the server through a firewall and a switch.

[0010] Preferably, the oil pillow comprises a local oil pillow and an on-load tap changer oil pillow, one hydraulic sensor is arranged on a pipeline between the on-load tap changer oil pillow and the transformer body, and another hydraulic sensor is arranged on a pipeline between the local oil pillow and the transformer body.

[0011] Preferably, a gas relay is further arranged on the pipeline between the oil pillow and the hydraulic sensor.

[0012] Preferably, the oil leakage detection sensor is one of a capacitive oil leakage detection sensor, an electronic oil leakage detection sensor and an ultrasonic oil leakage detection sensor.

[0013] The application further provides an online oil leakage monitoring method for large oil-immersed transformer equipment, comprising the online oil leakage monitoring device for large oil-immersed transformer equipment as described above, and further comprising the following steps:

[0014] S1: the center line of the pipeline between the oil pillow and the transformer body is set as a reference surface, the hydraulic sensor is arranged on the reference surface, and the height change AH of the oil in the oil pillow is calculated according to the detection value P of the hydraulic sensor;

[0015] The specific steps of calculating the height change of the oil in the oil pillow according to the hydraulic sensor are as follows:

[0016] The pressure P on the reference surface is calculated by the following formula (1),

[0017] P=P atm +P0+P f (1)

[0018] In the formula,

[0019] P0 is the pressure of the oil in the oil pillow on the reference surface,

[0020] P f is the pressure of the oil in the transformer body on the reference surface,

[0021] P atm is the pressure of the atmosphere on the reference surface,

[0022] The pressure P0 of the oil in the oil pillow on the reference surface is calculated according to the following formula (2),

[0023] P0=ρg(H-h1)=ρgΔH (2)

[0024] In the formula,

[0025] ρ represents the density of the liquid,

[0026] g is the acceleration of gravity,

[0027] ΔH represents the height change of the oil in the oil pillow, ΔH=H-h1,

[0028] H represents the height of the oil surface of the oil pillow to the reference surface,

[0029] h1 represents the height of the bottom of the oil pillow to the reference surface.

[0030] According to (1) formula and (2) formula calculation ΔH:

[0031]

[0032] S2: when the oil leakage detection sensor detects oil leakage, if the detection value of the hydraulic sensor does not change, the fire oil drain pipe is slightly leaked, otherwise the fire oil drain pipe is seriously leaked;

[0033] When the oil leakage detection sensor does not detect oil leakage, if the detection value of the hydraulic sensor does not change, the fire oil drain pipe is not leaked, otherwise the oil pillow trend needs to be continuously monitored to determine whether the transformer body leaks oil.

[0034] Preferably, in step S2, when the oil leakage detection sensor detects oil leakage, if the oil detection sensor detects the oil leakage speed v≤0.01, it is judged as a general defect; if the oil detection sensor detects the oil leakage speed 1≥v≥0.01, it is judged as a serious defect; if the oil detection sensor detects the oil leakage speed v≥1, it is judged as a crisis defect.

[0035] Compared with the prior art, the present application calculates the pressure at the hydraulic sensor through the pressure relationship between the oil pillow oil pressure, the atmospheric pressure and the transformer body oil pressure, and calculates the oil level of the oil pillow through the formula of pressure conversion into oil level. Then, through the cooperation of the oil pillow oil level change and the oil leakage detection sensor, it is judged whether the transformer body and the fire oil drain pipe leak oil, and whether the fire oil drain pipe leaks seriously when it leaks. The present application needs to install fewer sensors, has small modification to the transformer, has small modification cost and difficulty, and is beneficial to popularization. The present application fills the gap of intelligent monitoring of transformer oil leakage at present by developing an online monitoring device for oil leakage of large oil-immersed transformer equipment, improves the efficiency of routine inspection and patrol through intelligent technology, reduces equipment hidden dangers, and improves the stability of power grid. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a pressure relationship structure diagram between the oil pillow and the transformer body of an embodiment of the present application;

[0037] Figure 2 It is a structure diagram of an embodiment of the present application.

[0038] Explanation of reference signs:

[0039] 100. oil pillow, 1. transformer body, 2. hydraulic sensor, 3. fire oil drain pipe, 4. on-site data processing module, 5. mobile terminal, 6. communication module, 7. server, 8. transformer substation monitor, 9. production management system, 10. firewall, 11. switch, 12. local oil pillow, 13. on-load tap changer oil pillow, 14. gas relay, 15. oil leakage detection sensor, 16. reference surface. DETAILED DESCRIPTION

[0040] The present application will be described in detail below with reference to the embodiments shown in the drawings, but it should be noted that these embodiments are not a limitation on the present application, and equivalent transformations or substitutions of function, method, or structure made by those of ordinary skill in the art based on these embodiments are within the scope of the present application.

[0041] The large oil-immersed transformer type equipment referred to in the present application refers to three-phase donor transformers, three-phase split transformers, three-phase split reactors, large oil-immersed AC / DC transformers, and reactors, etc. of voltage levels of 110 kV and above.

[0042] The present application will be described in detail below with reference to the embodiments shown in the drawings, but it should be noted that these embodiments are not a limitation on the present application, and equivalent transformations or substitutions of function, method, or structure made by those of ordinary skill in the art based on these embodiments are within the scope of the present application. Figure 2 The present application will be described in detail below with reference to the embodiments shown in the drawings, but it should be noted that these embodiments are not a limitation on the present application, and equivalent transformations or substitutions of function, method, or structure made by those of ordinary skill in the art based on these embodiments are within the scope of the present application. The hydraulic sensor 2 is generally a high-precision hydraulic sensor, which monitors the change in the oil level of the oil pillow 100 by detecting the pressure of the pipeline between the transformer body 1 and the oil pillow 100. The fire oil discharge pipe 3 on the transformer body 1 is provided with an oil leakage detection sensor 15, which is used to detect whether the fire oil discharge pipe 3 is leaking oil, and can also be used for oil leakage detection of other non-oil filling pipeline structures.

[0043] As another embodiment of the present application: the present embodiment also includes an on-site data processing module 4 (IED), which is in communication connection with the hydraulic sensor 2 and the oil leakage detection sensor 15, respectively. The on-site data processing module 4 is used to collect the information sent by the two sensors and process the information (calculate the change in the height of the oil in the oil pillow 100 through the pressure data), and then perform a preliminary analysis according to the change in the oil level of the oil pillow 100 and the oil leakage of the fire oil discharge pipe 3 and send the preliminary analysis results to the server 7 or the mobile terminal 5.

[0044] As another embodiment of the present application: the present embodiment also includes a mobile terminal 5, which is connected with the on-site data processing module 4 through a communication module 6. Specifically, the communication module 6 is a 4G communication module.

[0045] As another embodiment of the present application: the present embodiment also includes a server 7, which is connected with the on-site data processing module 4, and the server 7 is connected with a substation monitor 8. The server 7 and the substation monitor 8 constitute a background service module, which is used for data processing, data storage, data query, data analysis, and sending of alarm information.

[0046] As another embodiment of the present application: the embodiment also includes a production management system 9 (PMS) connected with the server 7 through the firewall 10 and the switch 11.

[0047] As another embodiment of the present application: the oil pillow 100 includes a local oil pillow 12 and an on-load tap changer oil pillow 13, one hydraulic sensor 2 is arranged on the pipeline between the on-load tap changer oil pillow 13 and the transformer body 1, and another hydraulic sensor 2 is arranged on the pipeline between the local oil pillow 12 and the transformer body 1.

[0048] As another embodiment of the present application: a gas relay 14 is further arranged on the pipeline between the oil pillow 100 and the hydraulic sensor 2.

[0049] As another embodiment of the present application: the oil leakage detection sensor 15 is one of a capacitive oil leakage detection sensor, an electronic oil leakage detection sensor and an ultrasonic oil leakage detection sensor.

[0050] The present application collects the oil leakage condition of the fire oil discharge pipe 3 and the pressure change between the transformer body 1 and the oil pillow 100 through the sensors, to monitor the oil leakage condition of the fire oil discharge pipe 3 and the oil level change condition of the oil pillow 100 in real time, and to calculate data and analyze through the on-site data processing module 4. If the equipment is abnormal, the communication module 6 alarms the mobile terminal 5 and the server 7 alarms the transformer substation monitor 8, to realize the dynamic monitoring of the transformer. The equipment data is sent to the production management system 9 (PMS) to generate historical data, to provide a data basis for the judgment of the transformer state by the operating personnel.

[0051] The present application also provides an oil leakage online monitoring method for large oil-immersed transformer equipment, which comprises the large oil-immersed transformer equipment oil leakage online monitoring device and the following steps.

[0052] Step one: refer to the attached drawings Figure 1 The center line of the pipeline between the oil pillow 100 and the transformer body 1 is set as the reference surface 16, the hydraulic sensor 2 is arranged on the reference surface 16, and the height change ΔH of the oil in the oil pillow 100 is calculated according to the detection value P of the hydraulic sensor 2;

[0053] The specific steps of calculating the height change of the oil in the oil pillow 100 according to the hydraulic sensor 2 are as follows:

[0054] The pressure P on the reference surface 16 is calculated by the following formula (1),

[0055] P = P atm + P0+ P f (1)

[0056] In the formula, P is the pressure on the reference surface 16, P0 is the atmospheric pressure, and P is the pressure change of the oil in the oil pillow 100.

[0057] P0 is the pressure of the oil in the oil pillow 100 on the reference surface 16,

[0058] P f is the pressure of the oil in the transformer body 1 on the reference surface 16,

[0059] P atm is the atmospheric pressure on the reference surface 16,

[0060] The pressure P0 of the oil in the oil pillow 100 on the reference surface 16 is calculated according to the following formula (2), which is obtained based on the density-pressure relationship.

[0061] P0=ρg(H-h1)=ρgΔH (2)

[0062] Where:

[0063] ρ represents the density of the liquid,

[0064] g is the acceleration due to gravity,

[0065] ΔH represents the height change of the oil in the oil pillow 100, ΔH=H-h1,

[0066] H represents the height from the oil level of the oil pillow 100 to the reference surface 16,

[0067] h1 represents the height from the bottom of the oil pillow 100 to the reference plane 16;

[0068] When the transformer is operating normally, the internal pressure of the transformer body 1 remains unchanged. The pressure P of the oil in the transformer body 1 against the reference surface 16 is f Unchanged, due to atmospheric pressure P atm is a constant, ΔH can be calculated according to equations (1) and (2):

[0069]

[0070] Therefore, the change in the oil level in the oil pillow 100 can be determined by the pressure P detected by the hydraulic sensor 2. When the pressure P decreases, it means that the oil level in the oil pillow 100 has dropped.

[0071] Step 2: Referring to Table 1, when the oil leakage detection sensor 15 detects an oil leak, if the detection value of the hydraulic sensor 2 does not change, the fire oil drain pipe 3 has a slight oil leak; otherwise, the fire oil drain pipe 3 has a serious oil leak;

[0072] When the oil leakage detection sensor 15 does not detect oil leakage, if the detection value of the hydraulic sensor 2 does not change, the fire oil drain pipe 3 does not leak oil. Otherwise, it is necessary to continuously monitor the trend of the oil pillow 100 to determine whether the transformer body 1 leaks oil.

[0073] Table 1

[0074]

[0075] In the table, 0 represents no change, and 1 represents a change. For example, if the detection value of the oil leakage detection sensor 15 does not change, it indicates that there is no oil leakage; otherwise, it indicates that there is oil leakage. If the detection value of the hydraulic sensor 2 does not change, it indicates that the height of the oil in the oil reservoir 100 does not change; otherwise, it indicates that the height of the oil in the oil reservoir 100 changes.

[0076] In the table, when the oil leakage detection sensor 15 does not change, the hydraulic sensor 2 detects a decrease in the height in the oil reservoir 100. If there is no further decrease or the oil level rises within a certain period of time, it may be caused by other factors. If it continues to decrease within a certain period of time, it indicates that the transformer body 1 has oil leakage, resulting in a decrease in the height of the oil in the oil reservoir 100.

[0077] In step S2, in combination with the actual situation of the field device, the defect limits are summarized through a large number of tests and actual applications. According to the test data calculation and analysis, the oil leakage rate is taken as the defect limit at ν = 0.01 L / h and ν = 1 L / h. Specifically, referring to Table 2, when the oil leakage detection sensor 15 detects oil leakage, if the oil detection sensor detects that the oil leakage speed ν ≤ 0.01, it is judged as a general defect; if the oil detection sensor detects that the oil leakage speed 1 ≥ ν ≥ 0.01, it is judged as a serious defect; if the oil detection sensor detects that the oil leakage speed ν ≥ 1, it is judged as a crisis defect. Since the oil leakage defect is still determined by subjective and artificial methods at present, there is no objective and mathematical way to determine the concept, so the present application formulates the oil leakage defect and mathematically determines the defect type, which is beneficial to improve the level of equipment technology and intelligence and reduce safety risks.

[0078] Table 2

[0079]

[0080] One way to calculate the oil leakage rate: the height of the oil in the oil reservoir 100 is h0 mm, after a period of time T, the height of the oil in the oil reservoir 100 decreases by h2 mm, so the height of the oil in the oil reservoir 100 at this time is (h0-h2) mm. The volume of the oil in the oil reservoir 100 before time T and the volume of the oil in the oil reservoir 100 after time T are calculated, and then the volume M of the oil in the oil reservoir 100 that decreases within time T is calculated, and the oil leakage rate is

[0081] The present application calculates the pressure at the hydraulic sensor 2 through the pressure relationship among the oil pressure of the oil pillow 100, the atmospheric pressure and the oil pressure of the transformer body 1, and calculates the oil level of the oil pillow 100 through the formula of pressure conversion into oil level. Then, through the cooperation of the oil level change of the oil pillow 100 and the oil leakage detection sensor 15, it is judged whether the transformer body 1 and the fire oil drain pipe 3 leak oil, and whether the oil leakage of the fire oil drain pipe 3 is serious. The present application needs to install less sensors, has small modification to the transformer, has small modification cost and difficulty, and is beneficial to popularization. The present application fills the gap of intelligent monitoring of transformer oil leakage at present through the development of a large oil-immersed transformer equipment oil leakage online monitoring device, improves the inspection and patrol efficiency through intelligent technology, reduces the equipment hidden danger, and improves the stability of power grid.

[0082] The large oil-immersed transformer equipment oil leakage online monitoring device of the present application is mainly suitable for large power oil-immersed AC / DC transformer and reactor, and is also suitable for application in the oil leakage and liquid level monitoring of the fire oil drain pipe 3 of large storage insulating oil equipment of Sinopec and China Petroleum.

[0083] The above series of detailed descriptions are only specific descriptions of the feasible embodiments of the present application, and are not used to limit the protection scope of the present application, and equivalent embodiments or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

[0084] In addition, it should be understood that although the present application is described in the form of embodiments, not every embodiment contains only one independent technical solution, and the description manner of the specification is only for the sake of clarity, and the person skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be properly combined to form other embodiments that can be understood by the person skilled in the art.

Claims

1. A method for on-line monitoring of oil leakage in large oil-immersed transformer type equipment, characterized in that, The hydraulic sensor is arranged on the pipeline between the transformer body and the oil conservator, the fire-fighting oil discharge pipe on the transformer body is provided with an oil leakage detection sensor, and the method comprises the following steps: S1: the center line of the pipeline between the oil conservator and the transformer body is set as a reference surface, the hydraulic sensor is arranged on the reference surface, and the height change ΔH of the oil in the oil conservator is calculated according to the detection value P of the hydraulic sensor; The specific steps of calculating the height change ΔH of the oil in the oil conservator according to the hydraulic sensor are as follows: The pressure P on the reference surface is calculated by the following formula (1), （1）； In the formula, P0 is the pressure of the oil in the oil conservator on the reference surface, P f the pressure of the oil in the transformer body to the reference surface, P atm P is the pressure of the atmosphere on the reference surface, The pressure P0 of the oil in the oil conservator on the reference surface is calculated according to the following formula (2), （2）； In the formula, ρ represents the density of the liquid, g is the acceleration of gravity, ΔH represents the height change of the oil in the oil conservator, ΔH=H-h1, H represents the height of the oil surface of the oil conservator to the reference surface, h1 represents the height of the bottom of the oil conservator to the reference surface; ΔH is calculated according to the formula (1) and the formula (2): （3）； S2: when the oil leakage detection sensor detects oil leakage, if the detection value of the hydraulic sensor does not change, the fire-fighting oil discharge pipe is slightly leaked, otherwise the fire-fighting oil discharge pipe is seriously leaked; When the oil leakage detection sensor does not detect oil leakage, if the detection value of the hydraulic sensor does not change, the fire-fighting oil discharge pipe is not leaked, otherwise the trend of the oil conservator needs to be continuously monitored to determine whether the transformer body is leaked; One calculation method of the oil leakage rate: the height of the oil in the oil reservoir is hO mm calculated by formula (3), the height of the oil in the oil reservoir is reduced by h2 mm after time T, and the height of the oil in the oil reservoir at this time is (hO-h2) mm; the volume of the oil in the oil reservoir before time T and the volume of the oil in the oil reservoir after time T are calculated, and then the volume M of the oil in the oil reservoir reduced in time T is calculated, and the oil leakage rate is ; If the oil leakage speed v≤0.01, it is judged as a general defect; if the oil leakage speed 1≥v≥0.01, it is judged as a serious defect; and if the oil leakage speed v≥1, it is judged as a crisis defect.

2. The method according to claim 1, wherein, The on-site data processing module is further included, and the on-site data processing module is in communication connection with the hydraulic sensor and the oil leakage detection sensor respectively.

3. The method according to claim 2, wherein, The mobile terminal is further included, and the mobile terminal is connected with the on-site data processing module through the communication module.

4. The method according to claim 3, wherein, The server is further included, and the server is connected with the on-site data processing module, and the server is connected with the transformer substation monitor.

5. The method according to claim 4, wherein, The production management system is further included, and the production management system is connected with the server through the firewall and the switch.

6. The method for on-line monitoring of oil leakage of large oil-immersed transformer type equipment according to claim 1, characterized in that, The oil conservator comprises a local oil conservator and an on-load tap changer oil conservator, one hydraulic sensor is arranged on the pipeline between the on-load tap changer oil conservator and the transformer body, and another hydraulic sensor is arranged on the pipeline between the local oil conservator and the transformer body.

7. The method according to claim 6, wherein, A gas relay is further arranged on the pipeline between the oil conservator and the hydraulic sensor.

8. The method for on-line monitoring of oil leakage of large oil-immersed transformer type equipment according to claim 1, characterized in that, The oil leakage detection sensor is one of a capacitive oil leakage detection sensor, an electronic oil leakage detection sensor and an ultrasonic oil leakage detection sensor.

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