A gas relay and diagnosis method for real-time detection of transformer faults

Abstract

A gas relay and diagnostic method for real-time detection of transformer faults, the gas relay comprising: a gas relay body, an oil inlet, an oil outlet, a first air pipe, a bottle to be inspected, a gas relay vent valve, and a collection and sending unit. A fault gas detection module connected to the collection and sending unit is provided in the bottle to be inspected, for detecting whether the bottle to be inspected contains hydrocarbon gas and its concentration, gas color, and whether it contains irritating odor gas; if the pressure sensor detects that the gas pressure inside the gas relay body reaches a threshold value K1, the air intake solenoid valve is controlled to open, and the gas inside the gas relay body enters the bottle to be inspected through the air intake solenoid valve and the oil filter. Compared with the prior art, the present invention comprehensively evaluates the severity of transformer faults, wins extremely valuable time for transformer operation and maintenance, and eliminates the need for traditional operators to go to the substation to take gas and return to the laboratory for testing.

Description

Technical Field

[0001] The present invention belongs to the technical field of power equipment quality detection, and more specifically, relates to a gas relay and a diagnosis method for real-time detection of transformer faults. Background Art

[0002] Gas relays mainly play a basic protective role inside power transformers. The application of gas relays shows that when the insulation of the transformer decomposes rapidly or the transformer body has a discharge fault, the gas relay often quickly reflects the degree of the fault and disconnects the power supply in time, effectively reducing the losses caused by the transformer fault and avoiding the expansion of the transformer accident. However, due to reasons such as air entering the transformer and temperature drop, gas relays often malfunction (partly due to air mixing into the gas relay), causing alarms or tripping, while in fact the transformer is not faulty, which seriously affects the reliable operation of the transformer.

[0003] After a certain amount of gas is gathered in the gas relay, an alarm signal is issued. Generally, the operator needs to go to the substation to conduct transformer oil tests and gas detection to further diagnose whether the transformer is faulty gas or air. The traditional method is to cut off the power of the transformer, arrange personnel to take gas from the transformer gas relay, and send it to the laboratory for testing. It often takes 1-2 days from the gas relay gathering gas to the diagnosis result. This work efficiency is extremely low. Once the transformer has a sudden serious fault, there is no time to take measures according to the diagnosis results. The transformer is seriously damaged or even burned, causing a serious accident. In addition, there is a great safety risk for the operator to take gas on site when the transformer is energized. Once the transformer suddenly fails, it will seriously threaten the personal safety of the operator and cause immeasurable consequences.

[0004] In the existing patent technology descriptions, most of them are limited to improving the gas relay itself, and cannot effectively judge whether the transformer is a fault gas and the severity of the fault. Representative patents include a transformer fault gas collection device and method (CN201811304616.2). This method identifies whether it is a fault gas by ignition. This method has poor effectiveness and real-time performance. Some fault gas components are not necessarily flammable. On-site operation is extremely dangerous, and the work efficiency is low and the fault situation cannot be judged in time. This method also requires the transformer to be powered off, which seriously affects the reliability of power supply. Summary of the invention

[0005] In order to solve the problems in the prior art of transformer gas relays malfunctioning due to other interferences, causing alarms, untimely gas detection, and poor effectiveness of a single detection method, which lead to transformer damage or even burning, and other accident expansion problems, and to improve the reliability of transformer safe operation, the purpose of the present invention is to provide a gas relay for real-time detection and diagnosis of transformer faults and a method for identifying and judging transformer faults, quickly detect whether the gas gathered in the gas relay is gas generated by the fault or gas generated by non-fault reasons, and comprehensively judge the severity of the transformer fault by detecting the smell, composition, and color of the gas. After detection, the device of the present invention quickly sends diagnostic information to the transformer operator through the cloud platform, and can diagnose the transformer operating status before the transformer develops into a serious fault, thereby winning precious processing time for the transformer operator to inspect and maintain, and preventing damage to the transformer due to untimely processing.

[0006] The present invention adopts the following technical solution. A gas relay for real-time detection of transformer faults comprises: a gas relay body, an oil inlet, an oil outlet, a first air pipe, a bottle to be inspected, a gas relay venting valve and a collection and sending unit, wherein one end of the bottle to be inspected is connected to the gas relay body through the first air pipe, and the other end is connected to the gas relay venting plug through the second air pipe; a fault gas detection module connected to the collection and sending unit is arranged in the bottle to be inspected, and is used to detect whether the bottle to be inspected contains hydrocarbon gas and its concentration, gas color and whether it contains irritating odor gas; an oil filter is arranged at one end of the first air pipe close to the bottle to be inspected, a pressure sensor is arranged at one end of the first air pipe close to the gas relay body, and an air intake solenoid valve is arranged between the oil filter and the pressure sensor, and both are connected to the collection and sending unit; if the pressure sensor detects that the gas pressure inside the gas relay body reaches a threshold value K1, the air intake solenoid valve is controlled to open, and the gas inside the gas relay body enters the bottle to be inspected through the air intake solenoid valve and the oil filter; the collection and sending unit is arranged above the gas relay body, connected to the fault gas detection module, and is used to generate a transformer fault level evaluation result and send alarm information to the background.

[0007] Preferably, the threshold value K1 is set to 0.1-2 kPa. Further preferably, after the air intake solenoid valve is opened, if the pressure sensor detects that the gas pressure inside the gas relay body drops below the threshold value K1, the air intake solenoid valve is controlled to be closed.

[0008] Preferably, the faulty gas detection module comprises: a hydrocarbon detection sensor on the upper side of the bottle to be inspected, a color change sensor and an electronic nose sensor arranged on the side of the bottle to be inspected, all of which are connected to the collection and transmission unit.

[0009] Preferably, an exhaust solenoid valve is arranged on the upper side of the inside of the bottle to be inspected, which is used to control the discharge of the gas inside the bottle to be inspected, and is connected to the collection and sending unit. After the fault gas detection module inside the bottle to be inspected completes the detection, the exhaust control solenoid valve is opened to release the gas inside the bottle to be inspected. Further preferably, the exhaust control solenoid valve is provided with a check valve to control the external air from entering the bottle to be inspected, and only the gas inside the bottle to be inspected is discharged, and the exhaust control solenoid valve is automatically closed.

[0010] Preferably, the outside of the acquisition and transmission unit adopts a semi-enclosed spherical metal shell cover structure, and the edge of the cover is greater than 1 cm away from the lowest end of the signal acquisition and transmission unit. Further preferably, this distance is set to 1-5 cm to shield interference from surrounding charged bodies and prevent rain.

[0011] The present invention also provides a diagnostic method for a gas relay using the real-time transformer fault detection method, comprising the following steps:

[0012] Step 1: After gas accumulation occurs inside the transformer, if the pressure sensor detects that the gas pressure inside the gas relay body reaches the threshold value K1, the air intake solenoid valve is controlled to open, and the gas inside the gas relay body enters the bottle to be tested; thereafter, if the pressure sensor detects that the gas pressure inside the gas relay body drops below the threshold value K1, the air intake solenoid valve is controlled to close;

[0013] Step 2: The fault gas detection module in the bottle to be tested detects whether the bottle to be tested contains hydrocarbon gas and its concentration C CH , gas color and whether it contains pungent odor gas, generating a hydrocarbon gas detection result represented by a first eigenvalue Pq, a gas color detection result represented by a second eigenvalue Ps, and a pungent odor gas detection result represented by a third eigenvalue Pd;

[0014] Step 3, using the first eigenvalue Pq, the second eigenvalue Ps and the third eigenvalue Pd generated in step 2 as bases, multiplying them after exponential operation to obtain a transformer fault diagnosis evaluation coefficient P, and dividing the transformer fault level according to the transformer fault diagnosis evaluation coefficient P;

[0015] Step 4: The acquisition and transmission unit sends the fault level assessment results to the cloud server, sends the analysis results to the transformer operation or management user APP, and issues an early warning;

[0016] Step 5: After all sensors inside the bottle to be inspected complete the detection, the exhaust control solenoid valve is opened to release the gas inside the bottle to be inspected. When the relative pressure inside and outside the bottle to be inspected is zero, the exhaust control solenoid valve is controlled to close automatically.

[0017] Preferably, in step 2, the hydrocarbon gas detection result represented by the first characteristic value Pq is expressed by the following formula:

[0018]

[0019] Where:

[0020] Pq represents the first eigenvalue,

[0021] C CH Indicates hydrocarbon gas concentration;

[0022] Preferably, the second characteristic value Ps represents the gas color detection result, which is expressed by the following formula:

[0023]

[0024] Where:

[0025] Ps represents the second eigenvalue;

[0026] Preferably, the third characteristic value Pd represents the irritating odor gas detection result, which is expressed by the following formula:

[0027]

[0028] Where:

[0029] Pd represents the third eigenvalue.

[0030] Preferably, in step 3, the first eigenvalue Pq, the second eigenvalue Ps and the third eigenvalue Pd generated in step 2 are used to comprehensively analyze and diagnose the transformer fault, which can be expressed as follows:

[0031]

[0032] Where:

[0033] P represents the transformer fault diagnosis evaluation coefficient,

[0034] Pq represents the first eigenvalue,

[0035] Ps represents the second eigenvalue,

[0036] Pd represents the third eigenvalue.

[0037] Preferably, in step 3, the transformer fault diagnosis evaluation coefficient P is used to judge the transformer fault, which is expressed by the following formula:

[0038]

[0039] Where:

[0040] P represents the transformer fault diagnosis evaluation coefficient.

[0041] Preferably, in step 4, if the fault level assessment result is any one of a general fault, a serious fault or a critical fault, the analysis result is immediately accessed to the transformer operation or management user APP, and a timely warning is issued; the user APP can access and display the transformer's diagnostic data and analysis results in real time.

[0042] The beneficial effect of the present invention is that, compared with the prior art, when the gas relay of the transformer gathers gas and causes the gas pressure to increase to K1, by setting the size of K1, a small amount of gas (less than 100mL) can enter the bottle to be tested, while the traditional gas relay needs to reach 300mL of gas before alarming, which is more sensitive than the present invention. The gas detected by the comprehensive diagnosis of hydrocarbon detection sensors, electronic nose sensors, and color change sensors is the characteristic gas or air generated by the transformer failure. After the detection, the test results are quickly sent to the transformer operation or management personnel through the cloud server, and the severity of the transformer failure is accurately evaluated, which wins extremely valuable time for the operation and maintenance of the transformer, and eliminates the traditional operation personnel from going to the substation to take gas and returning to the laboratory for testing.

[0043] The patent of this invention uses comprehensive detection and diagnosis of gas composition, color, and odor, with fast detection, accurate diagnosis, and strong effectiveness. After detection, the results are sent to the cloud in real time for calculation and analysis, which greatly improves work efficiency, improves the safe operation level of the transformer, and ensures the safety of operators. The implementation of this invention is of great significance for discovering latent faults of transformers in advance and ensuring the safe operation of transformers. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the structure of a gas relay for real-time transformer fault detection provided by the present invention;

[0045] Figure 2 A schematic diagram of a gas relay detection unit for real-time detection of transformer faults provided by the present invention;

[0046] Figure 3 This is a schematic diagram of the outer cover of the collection and sending unit of the present invention;

[0047] Figure 4 This is a flow chart of the signal acquisition and sending unit of the present invention.

[0048] In the figure:

[0049] 1- Gas relay body;

[0050] 2-Observation window;

[0051] 3-Oil inlet;

[0052] 4-Oil outlet;

[0053] 5-First trachea;

[0054] 6-Bottles to be inspected;

[0055] 7- vent plug;

[0056] 8- Collection and sending unit;

[0057] 9-probe;

[0058] 10-Hydrocarbon sensor;

[0059] 11- Color change sensor;

[0060] 12-Electronic nose sensor;

[0061] 13- Oil filter;

[0062] 14-Intake control solenoid valve;

[0063] 15-pressure sensor;

[0064] 16-Exhaust control solenoid valve;

[0065] 17- Collection and transmission unit cover. DETAILED DESCRIPTION

[0066] The present application is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present application.

[0067] First embodiment: A gas relay for real-time detection of transformer faults

[0068] like Figure 1 As shown, the present invention provides a gas relay for real-time detection of transformer faults, comprising: a gas relay body 1, an observation window 2, an oil inlet 3, an oil outlet 4, a first gas pipe 5, a bottle to be inspected 6, a gas relay vent plug 7, a collection and sending unit 8 and a probe 9.

[0069] The inspection bottle 6 is a transparent container for collecting the gas released from the gas relay body 1. One end of the inspection bottle 6 is connected to the gas relay body 1 through the first gas pipe 5, and the other end is connected to the gas relay vent plug 7 through the second gas pipe.

[0070] like Figure 2As shown, a fault gas detection module connected to the collection and transmission unit 8 is provided in the to-be-tested bottle 6, and is used to detect whether hydrocarbon gas is contained in the to-be-tested bottle 6, its concentration, gas color, and whether irritating odor gas is contained. It is understandable that the technicians in the field can arbitrarily configure the sensors used in the fault gas detection module and their installation positions according to the actual situation on site, and these sensors can be multiple single-function sensors or multifunctional sensors integrating multiple functions.

[0071] In order to clearly introduce the implementation mode of the present invention, a preferred but non-restrictive configuration is introduced in the first embodiment of the present invention. The fault gas detection module includes: a hydrocarbon detection sensor 10, a color change sensor 11 and an electronic nose sensor 12.

[0072] The hydrocarbon detection sensor 10 is arranged on the upper side of the bottle to be inspected 6 and is connected to the collection and transmission unit 8 to detect whether the bottle to be inspected 6 contains hydrocarbon gas and its concentration C CH The first characteristic value Pq represents the hydrocarbon gas detection result, which is expressed by the following formula:

[0073]

[0074] Where:

[0075] Pq represents the first eigenvalue,

[0076] C CH Indicates the concentration of hydrocarbon gases.

[0077] The color change sensor 11 is arranged on the inner side of the bottle to be inspected 6 and connected to the collection and transmission unit 8 to detect the color of the gas in the bottle to be inspected 6. The second characteristic value Ps represents the gas color detection result, which is expressed by the following formula:

[0078]

[0079] Where:

[0080] Ps represents the second eigenvalue.

[0081] The electronic nose sensor 12 is arranged on the inner side of the bottle 6 to be inspected and connected to the collection and transmission unit 8 to detect whether the bottle 6 to be inspected contains pungent odor gas. The third characteristic value Pd represents the pungent odor gas detection result, which is expressed by the following formula:

[0082]

[0083] Where:

[0084] Pd represents the third eigenvalue.

[0085] The oil filter 13 is arranged at one end of the first air pipe 5 close to the bottle to be inspected 6, and the pressure sensor 15 is arranged at one end of the first air pipe 5 close to the gas relay body 1, and is connected to the collection and transmission unit 8. The air intake solenoid valve 14 is arranged between the oil filter 13 and the pressure sensor 15, and is connected to the collection and transmission unit 8.

[0086] If the pressure sensor 15 detects that the gas pressure inside the gas relay body 1 reaches the threshold value K1, the air intake solenoid valve 14 is controlled to open, and the gas inside the gas relay body 1 enters the to-be-tested bottle 6 through the air intake solenoid valve 14 and the oil filter 13; thereafter, if the pressure sensor 15 detects that the gas pressure inside the gas relay body 1 drops below the threshold value K1, the air intake solenoid valve 14 is controlled to close. It is understandable that the technicians in the field can set the threshold value K1 arbitrarily according to the actual situation on site. A preferred but non-limiting implementation is to set the threshold value K1 to 0.1-2kpa according to different sensitivity requirements.

[0087] Compared with the prior art, when the transformer gas relay accumulates gas, causing the gas pressure to increase to the threshold value K1, by setting the threshold value K1, a small amount of gas can enter the bottle to be inspected. A preferred but non-limiting implementation is to set the threshold so that less than 100mL enters the bottle to be inspected, while the traditional gas relay will not alarm until 300mL of gas is reached. Compared with the present invention, the sensitivity is higher.

[0088] The exhaust solenoid valve 16 is arranged on the upper side of the inside of the bottle to be inspected 6, and is used to control the discharge of the gas inside the bottle to be inspected 6, and is connected to the collection and sending unit 8. After the various sensors inside the bottle to be inspected 6 complete the detection, the exhaust control solenoid valve 16 is opened to release the gas inside the bottle to be inspected 6. The exhaust control solenoid valve 16 is provided with a check valve to control the external air from entering the bottle to be inspected, and only the gas inside the bottle to be inspected is discharged. When the relative pressure inside and outside the bottle to be inspected 6 drops to 0, the exhaust control solenoid valve 16 is automatically closed.

[0089] The acquisition and transmission unit 8 is arranged above the gas relay body 1 and connected to the faulty gas detection module, and is used to send transformer fault information to the transformer operator in a timely manner. It is understandable that each sensor and valve works under the control of the acquisition and transmission unit 8, collects data, and after data analysis and calculation, sends fault information to the user through the acquisition and transmission unit 8. The technical personnel in the field can realize the data processing and control function of the acquisition and transmission unit 8 in any way, including but not limited to, a data processing and control module based on a single chip microcomputer, etc. Figure 3As shown, the outside of the acquisition and sending unit 8 adopts a semi-enclosed spherical metal shell cover 17 structure, and the edges A and B of the cover are greater than 1 cm away from the lowest end of the signal acquisition and sending unit. This distance is set to 1-5 cm, which can not only shield the influence of surrounding charged bodies, but also send the acquisition signal to the outside and have the function of long-term rain protection.

[0090] It can be understood that the positions of the multiple sensors and valves arranged on or inside the bottle to be inspected 6 in the first embodiment of the present invention can be arbitrarily set by technicians in the field according to actual conditions on site. Without affecting their functions and ensuring good sealing, the sensors and valves are evenly distributed on the surface of the bottle to be inspected 6. The sensors and valves are arranged on the upper side, side or lower side of the bottle to be inspected 6, which are all technical means for implementing the present invention.

[0091] Second embodiment: A diagnostic method for real-time detection of transformer faults

[0092] like Figure 4 As shown, the second embodiment of the present invention provides a diagnostic method for a gas relay for real-time transformer fault detection using the above-mentioned method, comprising the following steps:

[0093] Step 1: Gas accumulation occurs inside the transformer. If the pressure sensor 15 detects that the gas pressure inside the gas relay body 1 reaches the threshold value K1, the air intake solenoid valve 14 is controlled to open, and the gas inside the gas relay body 1 enters the inspection bottle 6 through the air intake solenoid valve 14 and the oil filter 13; thereafter, if the pressure sensor 15 detects that the gas pressure inside the gas relay body 1 drops below the threshold value K1, the air intake solenoid valve 14 is controlled to close.

[0094] Step 2: The hydrocarbon detection sensor 10 disposed inside the bottle to be inspected 6 detects whether the bottle to be inspected 6 contains hydrocarbon gas and its concentration C CH , generating a hydrocarbon gas detection result represented by the first characteristic value Pq, which is expressed by the following formula:

[0095]

[0096] Where:

[0097] Pq represents the first eigenvalue,

[0098] C CH Indicates hydrocarbon gas concentration;

[0099] The color change sensor 11 detects the color of the gas in the bottle to be tested 6, and generates a second characteristic value Ps representing the gas color detection result, which is expressed by the following formula:

[0100]

[0101] Where:

[0102] Ps represents the second eigenvalue;

[0103] The electronic nose sensor 12 detects whether the bottle to be inspected 6 contains pungent odor gas, and generates a third characteristic value Pd representing the pungent odor gas detection result, which is expressed by the following formula:

[0104]

[0105] Where:

[0106] Pd represents the third eigenvalue.

[0107] Step 3, using the first eigenvalue Pq, the second eigenvalue Ps and the third eigenvalue Pd generated in step 2 to comprehensively analyze and diagnose the transformer fault, which is expressed as the following formula:

[0108]

[0109] Where:

[0110] P represents the transformer fault diagnosis evaluation coefficient,

[0111] Pq represents the first eigenvalue,

[0112] Ps represents the second eigenvalue,

[0113] Pd represents the third eigenvalue;

[0114] The transformer fault diagnosis evaluation coefficient P is used to judge the transformer fault, which is expressed as follows:

[0115]

[0116] Where:

[0117] P represents the transformer fault diagnosis assessment coefficient;

[0118] No fault indicates that the gas inside the gas relay body 1 is air, and the transformer can operate safely with power on. If the fault level is a critical fault, an emergency power outage is required.

[0119] It is understandable that the assignment of the first eigenvalue Pq, the second eigenvalue Ps and the third eigenvalue Pd used in this embodiment, and the power index used to calculate the fault diagnosis evaluation coefficient are all a preferred but non-restrictive choice. For example, the technical personnel in the field can assign the first eigenvalue Pq, the second eigenvalue Ps and the third eigenvalue Pd with fractions or decimals, larger or smaller values, or use other power indexes to obtain the fault diagnosis evaluation coefficient for the first eigenvalue Pq, the second eigenvalue Ps and the third eigenvalue Pd, and then re-divide the interval of the fault evaluation level. The preferred values ​​given in the present invention are only for the purpose of clearly introducing the technical solutions and beneficial effects of the present invention, and do not mean that the present invention must be implemented with these parameters.

[0120] Compared with the existing technology, the comprehensive diagnosis of hydrocarbon detection sensors, electronic nose sensors, and color change sensors can determine whether the gas detected is the characteristic gas generated by the transformer failure or air. After the detection, the test results are quickly sent to the transformer operation or management personnel through the cloud server, and the severity of the transformer failure is evaluated, which wins extremely valuable time for the transformer operation and maintenance, and eliminates the traditional operating personnel's need to go to the substation to take gas and return it to the laboratory for testing.

[0121] Step 4: The acquisition and sending unit 8 sends the fault level assessment result to the cloud serverless system. If the fault level assessment result is any one of a general fault, a serious fault or a critical fault, the analysis result is immediately accessed to the transformer operation or management user APP, and a warning is issued in time. The user APP can access and display the transformer's diagnostic data and analysis results in real time.

[0122] Step 5: After all sensors inside the bottle 6 to be inspected complete the detection, the exhaust control solenoid valve 16 is opened to release the gas inside the bottle 6 to be inspected. When the relative pressure inside and outside the bottle 6 to be inspected drops to 0, the exhaust control solenoid valve 16 is automatically closed.

[0123] The beneficial effect of the present invention is that, compared with the prior art, when the gas relay of the transformer gathers gas and causes the gas pressure to increase to K1, by setting the size of K1, a small amount of gas (less than 100mL) can enter the bottle to be tested, while the traditional gas relay needs to reach 300mL of gas before alarming, which is more sensitive than the present invention. The gas detected by the comprehensive diagnosis of hydrocarbon detection sensors, electronic nose sensors, and color change sensors is the characteristic gas or air generated by the transformer failure. After the detection, the cloud server quickly sends the test results to the transformer operation or management personnel, and evaluates the severity of the transformer failure, which wins extremely valuable time for the operation and maintenance of the transformer, and eliminates the traditional operation personnel from going to the substation to take gas and returning to the laboratory for testing.

[0124] In Example 1, gas accumulated in a gas relay of a certain transformer caused the gas relay to send out an alarm signal. It was impossible to determine at the first time whether it was gas or air caused by an internal fault of the transformer. Using the technology of the present invention, the hydrocarbon sensor detected hydrocarbon gas at 16.5ppm, and the Pq characteristic value was 2. The electronic nose sensor detected a pungent odor, and the Pd characteristic value was 2. The color change sensor detected the gas color as yellow, and the Ps characteristic value was 2. Through comprehensive detection and diagnosis, P was 17.8, and it was determined that there was an emergency fault inside the transformer, and the substation operating personnel were promptly notified that a power outage was needed for emergency treatment. After a timely power outage and inspection, it was found that there were serious discharge marks inside the transformer. By timely power outage and taking effective measures, further damage to the transformer and the expansion of the accident were avoided.

[0125] The patent of this invention uses comprehensive detection and diagnosis of gas composition, color, and odor, with high accuracy and strong effectiveness. After detection, the results are sent to the cloud in real time for calculation and analysis, which greatly improves work efficiency, improves the safe operation level of the transformer, and ensures the safety of operators. The implementation of this invention is of great significance for early detection of transformer faults and ensuring the safe operation of the transformer.

[0126] The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the drawings in the specification. However, those skilled in the art should understand that the above implementation examples are only preferred implementation schemes of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, but not to limit the scope of protection of the present invention. On the contrary, any improvements or modifications based on the inventive spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. A diagnostic method using a gas relay for real-time detection of transformer faults, characterized in that: The gas relay comprises: a gas relay body (1), an oil inlet (3), an oil outlet (4), a first gas pipe (5), a bottle to be inspected (6), a gas relay vent plug (7) and a collection and transmission unit (8), and is characterized in that: One end of the bottle to be tested (6) is connected to the gas relay body (1) via a first gas pipe (5), and the other end is connected to the gas relay vent plug (7) via a second gas pipe; a fault gas detection module connected to the collection and transmission unit (8) is provided in the bottle to be tested (6) to detect whether the bottle to be tested (6) contains hydrocarbon gas and its concentration, gas color, and whether it contains irritating odor gas; An oil filter (13) is provided at one end of the first air pipe (5) close to the bottle to be inspected (6), a pressure sensor (15) is provided at one end of the first air pipe (5) close to the gas relay body (1), and an air intake solenoid valve (14) is provided between the oil filter (13) and the pressure sensor (15), and both are connected to the collection and transmission unit (8); If the pressure sensor (15) detects that the gas pressure inside the gas relay body (1) reaches a threshold value K1, the air intake solenoid valve (14) is controlled to open, and the gas inside the gas relay body (1) enters the to-be-tested bottle (6) through the air intake solenoid valve (14) and the oil filter (13); The collection and transmission unit (8) is arranged above the gas relay body (1) and is connected to the fault gas detection module, and is used to generate a transformer fault level assessment result and send alarm information to the background; the fault gas detection module includes: a multi-function sensor or multiple single-function sensors; The diagnostic method comprises the following steps: Step 1: After gas accumulation occurs inside the transformer, if the pressure sensor (15) detects that the gas pressure inside the gas relay body (1) reaches a threshold value K1, the air intake solenoid valve (14) is controlled to open, and the gas inside the gas relay body (1) enters the test bottle (6); thereafter, if the pressure sensor (15) detects that the gas pressure inside the gas relay body (1) drops below the threshold value K1, the air intake solenoid valve (14) is controlled to close; Step 2: The fault gas detection module in the test bottle (6) detects whether the test bottle (6) contains hydrocarbon gas and its concentration. , gas color and whether it contains pungent odor gas, generating the first characteristic value The representative hydrocarbon gas detection result is the second characteristic value Represents the gas color detection result, and the third characteristic value Represents the detection result of irritating odor gas; The first eigenvalue The representative hydrocarbon gas detection results are expressed by the following formula: Where: represents the first eigenvalue, Indicates hydrocarbon gas concentration; The second eigenvalue Represents the gas color detection result, expressed as follows: Where: represents the second eigenvalue; The third eigenvalue Represents the detection result of irritating odor gas, expressed by the following formula: Where: represents the third eigenvalue; Step 3: Use the first eigenvalue generated in step 2 , the second eigenvalue and the third eigenvalue As the base, multiply after exponential operation to obtain the transformer fault diagnosis evaluation coefficient , expressed as the following formula, Where: P represents the transformer fault diagnosis evaluation coefficient, represents the first eigenvalue, represents the second eigenvalue, represents the third eigenvalue; Transformer fault diagnosis evaluation coefficient The transformer fault level is divided into the following formula: Where: P represents the transformer fault diagnosis assessment coefficient; Step 4, the acquisition and transmission unit (8) transmits the fault level assessment result to the cloud server, transmits the analysis result to the transformer operation or management user APP, and issues a real-time warning; Step 5, after all sensors inside the bottle to be inspected (6) complete the detection, the exhaust control solenoid valve (16) is opened to release the gas inside the bottle to be inspected (6), and when the relative pressure inside and outside the bottle to be inspected (6) is zero, the exhaust control solenoid valve (16) is controlled to close automatically; An exhaust solenoid valve (16) is provided on the upper side of the interior of the bottle to be tested (6) for controlling the discharge of gas inside the bottle to be tested (6) and is connected to the collection and transmission unit (8). After the fault gas detection module inside the bottle to be tested (6) completes the detection, the exhaust control solenoid valve (16) is opened to release the gas inside the bottle to be tested (6); the exhaust control solenoid valve (16) is provided with a check valve to prevent external air from entering the bottle to be tested and only discharge the gas inside the bottle to be tested, and the exhaust control solenoid valve (16) is automatically closed.

2. The diagnostic method according to claim 1, characterized in that: The threshold value K1 is set to 0.1-2 kPa. After the air intake solenoid valve (14) is opened, if the pressure sensor (15) detects that the gas pressure inside the gas relay body (1) drops below the threshold value K1, the air intake solenoid valve (14) is controlled to be closed.

3. The diagnostic method according to claim 1 or 2, characterized in that: The fault gas detection module comprises: a hydrocarbon detection sensor (10) on the upper side of the interior of the bottle to be detected (6), a color change sensor (11) and an electronic nose sensor (12) arranged on the side of the interior of the bottle to be detected (6), all of which are connected to the collection and transmission unit (8).

4. The diagnostic method according to claim 1 or 2, characterized in that: The outside of the signal collection and transmission unit (8) adopts a semi-enclosed spherical metal shell cover (17) structure, and the edge of the cover is greater than 1 cm away from the lowest end of the signal collection and transmission unit (8) to shield the interference of surrounding charged bodies and prevent rain.

5. The diagnostic method according to claim 1, characterized in that: In step 4, if the fault level assessment result is any of general fault, serious fault or critical fault, the analysis result is immediately accessed to the transformer operation or management user APP, and a warning is issued in time; The user APP can access and display the transformer's diagnostic data and analysis results in real time.

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