A device and method for aging test of transformer seals under multi-stress combined action

Abstract

The present invention discloses an aging test device for transformer seals under the combined action of multiple stresses, comprising a test cavity, a heater, a vibrator, an oil pump, and a seal specimen fixing structure. The seal specimen fixing structure is disposed within the test cavity, and the test cavity is connected to the heater, the vibrator, and the oil pump, respectively. The heater is used to heat the test cavity, the vibrator is used to vibrate the test cavity, and the oil pump is used to input transformer oil into the test cavity to generate oil pressure for the seal specimen. This device is used to address the problem of significant discrepancies between the test conditions of existing transformer seal accelerated aging test methods and actual operating conditions, simulate the aging process of seals under the combined action of oil pressure, temperature, and vibration, and ensure that the test conditions are aligned with actual conditions.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to an aging test device and method for transformer seals under the combined action of multiple stresses. Background Art

[0002] Transformers are key components of electrical energy conversion. Oil-immersed transformers are common, using transformer oil as both insulation and cooling medium. Leakage of this oil can lead to performance failure and even malfunction. Seal failure, caused by seal aging, is a primary defect in transformers and poses a significant threat to the safe and reliable operation of transformer equipment. Transformer oil seal aging tests can be used to evaluate transformer seal performance and accurately determine the extent and rate of seal aging. This provides a basis for transformer seal replacement planning, ensuring both improved maintenance efficiency and the avoidance of resource waste caused by frequent seal replacement. Therefore, accurately simulating the seal aging process is of great engineering value in providing accurate information on the extent and rate of seal aging.

[0003] Existing aging testing methods for transformer oil seals typically involve immersing seal specimens in transformer oil and conducting accelerated aging tests at a constant temperature for a specified period of time. However, during actual transformer operation, seals are subjected to a combination of stresses, including heat, mechanical vibration, and oil pressure. In addition to thermal stress, mechanical vibration and oil pressure can also cause premature seal failure.

[0004] The test conditions of the existing test method are significantly different from the actual operating conditions, and cannot fully simulate the aging and failure process of the seal. The specific differences are: (1) Due to the change in the transformer load rate, the transformer oil temperature rises and falls in a cycle, and the temperature cannot be maintained constant. Using a constant temperature for accelerated aging test cannot simulate the temperature alternation process; (2) Mechanical vibration occurs during the operation of the transformer, and the seal is actually in a vibrating state rather than the static state assumed in the existing test method. It is necessary to analyze the impact of vibration on the seal; (3) The seal is installed at different positions in the transformer and is subjected to different transformer oil pressures. It is necessary to consider the impact of oil pressure on seal failure. Summary of the Invention

[0005] The present invention provides an aging test device and method for transformer seals under the combined action of multiple stresses, which is used to solve the problem that the test conditions of existing accelerated aging test methods for transformer seals are significantly different from the actual operating conditions. The device simulates the aging process of seals under the combined action of oil pressure, temperature and vibration, and ensures that the test conditions are consistent with the actual situation.

[0006] The present invention provides a transformer seal aging test device under multiple stress combined action, comprising

[0007] Test chamber, heater, vibrator, oil feeder and sealing specimen fixing structure,

[0008] The sealing sample fixing structure is arranged inside the test cavity.

[0009] The test cavity is connected to the heater, the vibrator and the oil feeder respectively.

[0010] The heater is used to heat the test cavity, the vibrator is used to vibrate the test cavity, and the oil feeder is used to feed transformer oil into the test cavity to generate oil pressure on the sealing component sample.

[0011] Furthermore, it is characterized in that it also includes an oil pressure measuring and controlling device, which is respectively connected to the test cavity and the oil transfer device, and is used to obtain the oil pressure value in the test cavity, and control the oil transfer device to output or input transformer oil according to the oil pressure value so that the oil pressure in the test cavity reaches the preset oil pressure value.

[0012] Furthermore, it also includes a temperature controller, which is connected to the test cavity and the heater respectively. The temperature controller is used to obtain the temperature value in the test cavity and control the working state of the heater according to the temperature value so that the temperature of the test cavity reaches a preset temperature value.

[0013] Furthermore, the heater is an electromagnetic heating coil, and the electromagnetic heating coil is equidistantly arranged outside the test cavity.

[0014] Furthermore, the sealing sample fixing structure includes a groove provided at the bottom of the test cavity, and the groove is used for placing the sealing sample.

[0015] Furthermore, the vibrator is a vibration test bench, and the vibration test bench is arranged at the bottom of the test cavity.

[0016] Furthermore, the oil delivery device includes an oil inlet pipe and an oil outlet pipe, and the oil inlet pipe and the oil outlet pipe are both connected to the test cavity.

[0017] In another aspect, the present invention provides a method for aging testing a transformer seal under multiple combined stresses, comprising the following steps:

[0018] S1. Input transformer oil into the test chamber until the oil pressure reaches a preset value;

[0019] S2, the heater heats the test cavity until the temperature reaches a preset value;

[0020] S3, the vibrator is started according to the preset vibration value;

[0021] S4. When the temperature, oil pressure and vibration parameters in the test cavity reach preset values ​​for a predetermined time, remove the sealing component sample.

[0022] Further, including:

[0023] If the oil pressure in the test cavity is higher than the preset oil pressure value, outputting the variable pressure oil from the test cavity until the preset oil pressure value is reached;

[0024] And / or if the temperature in the test chamber is higher than the preset temperature value, adjusting the heating temperature of the heater until the preset temperature value is reached.

[0025] Furthermore, the step S4 further includes:

[0026] S41, when the test cavity maintains the preset temperature value for a first preset time, turning off the heater to keep the temperature of the test cavity in a cooling state;

[0027] S42, when the cooling state of the test cavity is maintained for a second preset time, restarting the heater to heat the test cavity until the temperature reaches the preset value;

[0028] S43. Repeat steps S41 and S42 until the sealing member sample is taken out.

[0029] It can be seen from the above technical solutions that the present invention has the following advantages:

[0030] The test chamber of the present invention is used to hold transformer oil. By changing the volume of the transformer oil within the test chamber, the oil pressure within the test chamber is controlled, simulating the oil pressure environment of the seal within the transformer. A heater is used to heat the test chamber, thereby heating the transformer oil within the test chamber, simulating the temperature environment of the seal within the transformer. A vibrator vibrates the test chamber, simulating the mechanical vibration environment of the seal within the transformer. Therefore, the test apparatus of this embodiment accelerates the aging of the transformer seal under the combined effects of heat, mechanical vibration, and oil pressure, and the simulated test conditions are closer to actual operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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.

[0032] Figure 1The present invention is a schematic structural diagram of an aging test device for transformer seals under the combined action of multiple stresses.

[0033] Figure 2 The present invention is a flow chart of an aging test method for transformer seals under the combined action of multiple stresses.

[0034] Figure 3 This is a schematic diagram of the temperature control process in an aging test method for transformer seals under multiple combined stresses of the present invention.

[0035] Description of the drawings: 1. Transformer oil sampling device; 2. Solenoid valve; 3. Solenoid pump; 4. Pipeline; 5. Test chamber; 6. Oil pressure sensor; 7. Temperature sensor; 8. Electromagnetic heating coil; 9. Sealing specimen; 10. Vibration test bench; 11. Oil storage device; 12. Communication interface; 13. Data bus; 14. Control terminal. DETAILED DESCRIPTION

[0036] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below 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 creative work are within the scope of protection of the present invention.

[0037] The terms "first," "second," "third," "fourth," and so forth (if any) in the description and drawings of the present invention are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that, for example, the implementation of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, product, or apparatus.

[0038] See also Figure 1 , Figure 1 The present invention provides an aging test device for transformer seals under multiple stresses, comprising a test chamber 5, a heater, a vibrator, an oil feeder, and a sealing sample 9 fixing structure.

[0039] The sealing sample fixing structure is inside the test cavity 5.

[0040] The test chamber 5 is connected to the heater, vibrator and oil feeder respectively.

[0041] The heater is used to heat the sealing sample 9 , the vibrator is used to vibrate the sealing sample 9 , and the oil feeder is used to feed transformer oil into the test cavity 5 to generate oil pressure for the sealing sample 9 .

[0042] It will be understood that, in practice, test chamber 5 is used to hold transformer oil. The oil pressure within test chamber 5 is controlled by changes in the transformer oil volume, simulating the oil pressure environment of the seal within the transformer. A heater is used to heat test chamber 5, thereby heating the transformer oil within test chamber 5 and simulating the temperature environment of the seal within the transformer. A vibrator vibrates test chamber 5, simulating the mechanical vibration environment of the seal within the transformer. Therefore, the test apparatus of this embodiment accelerates the aging of the transformer seal under the combined effects of heat, mechanical vibration, and oil pressure, and the simulated test conditions are closer to actual operating conditions.

[0043] In a more specific embodiment, the test device also includes an oil pressure measuring and controlling device, which is respectively connected to the test cavity 5 and the oil transfer device. The oil pressure measuring and controlling device is used to obtain the signal of the oil pressure sensor 6 and control the oil transfer device to output or input transformer oil so that the oil pressure in the test cavity 5 reaches the preset oil pressure value.

[0044] In a more specific embodiment, the oil pressure monitor includes an oil pressure sensor 6, which is disposed at the top of the test chamber 5. It will be appreciated that the oil pressure sensor disposed at the top of the test chamber 5 can measure the oil pressure in the test chamber 5 while being minimally affected by the pressure of the transformer oil.

[0045] In a more specific embodiment, the oil delivery device includes an oil inlet pipeline, which connects the test chamber to the transformer oil sampling device through the oil inlet pipeline. The oil inlet pipeline is sequentially provided with a solenoid valve 2 and a solenoid pump 3. The solenoid valve 2 is located on a side close to the transformer oil sampling device 1, and the solenoid pump 3 is located on a side close to the test chamber 5. In a specific implementation, the solenoid valve 2 and the solenoid pump 3 are sequentially opened to allow the transformer oil from the transformer oil sampling device 1 to be transferred into the test chamber 5, thereby increasing the oil pressure within the test chamber 5.

[0046] In a more specific embodiment, the oil delivery device further includes an oil outlet pipeline connected to an oil storage device 11. The oil storage device 11 includes an electromagnetic pump and a solenoid valve. In practice, transformer oil within the test chamber 5 can be pumped into the oil storage device 11, and the transformer oil within the test chamber 5 can be discharged, thereby reducing the oil pressure within the test chamber 5.

[0047] It is understood that, in specific implementations, when the oil pressure in the test chamber is low, the transformer oil in the transformer oil sampling device 1 is input into the test chamber 5 by activating the electromagnetic pump 3 and the electromagnetic valve 2, thereby increasing the oil pressure in the test chamber 5. When the oil pressure in the test chamber 5 is high, the oil storage device is activated to output the transformer oil in the test chamber 5 to the oil storage device 11, thereby reducing the oil pressure in the test chamber 5. Therefore, this embodiment can achieve adjustable and controllable temperature in the test chamber 5, ensuring the accuracy of the oil pressure test conditions.

[0048] It can be understood that this embodiment realizes accelerated aging test of the seal under different oil pressures by separately setting up the oil inlet pipe and the oil outlet pipe, and cooperating with the oil pressure sensor 6, simulating the seal being installed at different positions of the transformer or withstanding different oil pressures.

[0049] In a more specific embodiment, the test device also includes a temperature controller, which is connected to the temperature sensor 7 and the heater respectively. The temperature controller is used to obtain the signal of the temperature sensor 7, control the working state of the heater, and the temperature of the test chamber 5 reaches a preset temperature value.

[0050] In a more specific embodiment, the temperature measurement and control device further includes a temperature sensor disposed at the top of the test chamber. It is understood that disposing the temperature sensor at the top of the test chamber allows for measurement of the temperature within the test chamber while minimizing the effect of transformer oil pressure.

[0051] In a more specific embodiment, the heater is an electromagnetic heating coil 8, which is arranged on the outside of the test cavity 5 and is used to heat the oil inside the test cavity 5. During implementation, multiple layers of electromagnetic heating coils 8 can be arranged and evenly distributed on the outer surface of the test cavity 5 to achieve uniform heating of the test cavity 5, reduce the difference in oil temperature at different locations in the test cavity 5, and avoid affecting the test results.

[0052] It is understood that, in practice, when the temperature in the test chamber is too high, the temperature in the test chamber is adjusted by changing the heating temperature of the electromagnetic heating coil 8. Therefore, this embodiment can achieve adjustable and controllable temperature in the test chamber 5, ensuring the accuracy of the temperature test conditions.

[0053] It should be noted that this embodiment is a combined aging test device, and its test environment is complex. During specific implementation, the temperature, oil pressure, and mechanical vibration in the test chamber will also affect each other:

[0054] After transformer oil is input into the test chamber 5 until the oil pressure reaches the preset value, the test chamber 5 is heated by the heater. During this process, the oil pressure will increase due to the influence of temperature. At this time, the oil pressure measurement and control device of this embodiment receives the oil pressure information in the test chamber in real time. When the oil pressure is too high, the oil pressure is reduced by outputting the transformer oil in the test chamber 5, and the oil pressure is maintained at the preset value again, thereby overcoming the problem that the oil pressure is affected by temperature.

[0055] After starting the vibrator, on the one hand, the strong vibration of the transformer oil may cause phenomena such as partial discharge, generating a small amount of gas. The presence of this gas in the oil may cause the oil pressure to change. If the gas is generated at a fast rate, it may cause the oil pressure to increase. On the other hand, the strong vibration of the transformer oil will cause friction between the transformer oil molecules, and heat will continue to accumulate, which may cause the temperature of the transformer oil to gradually increase. In this embodiment, during the vibration process of the test cavity 5, the oil pressure and temperature are controlled in real time by the oil pressure controller and the temperature controller, thereby overcoming the problem that the oil pressure and temperature are affected by mechanical vibration.

[0056] It should be noted that since the purpose of the seal aging test is to quickly evaluate the seal's quality and performance in a relatively short period of time, the preset temperature, oil pressure, and vibration values ​​used in the test are higher than the actual operating conditions of the transformer. Exceeding these preset values ​​can pose a safety hazard. The device of this embodiment can monitor in real time whether the temperature, oil pressure, and vibration values ​​have reached the preset values, ensuring the safe conduct of the aging test.

[0057] It should be noted that this embodiment can accurately control the temperature, oil pressure and vibration parameters in the test chamber 5 to maintain them at preset values, ensure the accuracy of the test conditions and thus obtain accurate test results for the seals, provide a basis for accurately estimating the service life of the seals, and achieve both control and improvement of maintenance efficiency and avoidance of waste of resources caused by frequent replacement of seals.

[0058] In a more specific embodiment, the seal sample fixing structure includes a groove provided at the bottom of the test cavity, and the groove is used to place the seal sample 9. In some specific implementation methods, the test cavity is composed of two parts, the upper part is a metal can body, and the lower part is a planar structure provided with a sealing groove. The two parts are sealed and connected by a seal and fixed with fixing bolts. In some specific implementation methods, the groove can be a rectangular groove or a semicircular groove. It is understandable that the seal is fixed in the groove and can vibrate synchronously with the test cavity when the vibrator is started. In some more specific implementation methods, the width of the groove is adjustable, which can prevent the aging failure characteristics of the seals in transformers of various types and sizes and has a wide range of applications.

[0059] In a more specific embodiment, the vibrator is a vibration test bench 10, which is fixedly mounted at the bottom of the test chamber 5. It will be appreciated that, unlike existing accelerated aging test methods for seals under constant mechanical stress or no mechanical stress, this embodiment proposes the use of a combination of the vibration test bench 10 and the test chamber 5 to simulate the mechanical vibration experienced by transformer seals, more closely resembling actual operating conditions and reflecting the failure patterns of seals under long-term, repetitive vibration conditions.

[0060] In a more specific embodiment, the aging test apparatus further includes a control terminal 14, which is respectively connected to the communication interface 12 on the solenoid valve 2, the solenoid pump 3, the oil pressure sensor 6, the temperature sensor 7, the electromagnetic heating coil 8, the vibration test bench 10, and the oil storage device 11 to achieve automated control. The control terminal 14 is electrically connected to the solenoid valve 2 and the electromagnetic pump 3 via the data bus 13 to control the start and stop of the solenoid valve 2 and the electromagnetic pump 3. The control terminal 14 is electrically connected to the oil pressure sensor 6 to monitor the oil pressure in the test chamber 5. The control terminal 14 is electrically connected to the temperature sensor 7 to monitor the temperature in the test chamber 5 and is electrically connected to the electromagnetic heating coil 8 to control the temperature in the test chamber 5 to reach a predetermined temperature. The control terminal is electrically connected to the communication interface 12 to control the oil storage device 11 to extract transformer oil from the test chamber 5, thereby reducing the oil pressure in the test chamber 5. The control terminal 14 is electrically connected to the vibration test bench 10 to control the vibration test bench 10 to vibrate according to a predetermined pattern to simulate the vibration characteristics of the actual operation of the transformer.

[0061] It can be understood that the working principle of this embodiment is:

[0062] Under the control of control terminal 14, transformer oil medium controllably enters the test chamber through transformer oil sampling device 1, solenoid valve 2, solenoid pump 3, and pipeline 4. The oil pressure within the chamber is monitored by oil pressure sensor 6 and then transmitted to control terminal 14 for control. The interior of test chamber 5 is heated by electromagnetic heating coil 8. The oil pressure within the chamber is monitored by temperature sensor 7 and then transmitted to control terminal 14 for control. Test chamber 5 is placed on a vibration test bench 10. The control terminal controls vibration test bench 10 to simulate mechanical vibrations in actual operating conditions. The seal specimen 9 to be tested is installed in a groove at the bottom of the test chamber. The present invention utilizes control terminal 14, data bus 13, temperature sensor 7, oil pressure sensor 6, and vibration test bench 10 to achieve controllable and adjustable temperature, vibration, and oil pressure within test chamber 5. This can simulate the accelerated aging process of transformer seals under actual operating conditions, which is affected by a combination of multiple factors such as temperature, mechanical vibration, and oil pressure. This simulated test conditions are closer to actual operating conditions.

[0063] In some more specific embodiments:

[0064] The oil pressure preset value and temperature preset value are both range values. The oil pressure preset value is 0.1-0.8MPa, and the temperature preset value is 40-105℃;

[0065] The vibration preset value includes the amplitude preset value and the frequency preset value. The amplitude preset value is 2mm and the vibration frequency preset value is 30Hz.

[0066] Solenoid valve 2 is a solenoid valve controlled by analog signal, and the control signal is 4-20mA analog signal;

[0067] Electromagnetic pump 3 is a 100W plunger pump, and the control signal is a 4-20mA analog signal;

[0068] Pipe 4 is a 6mm diameter corrosion-resistant stainless steel pipe. Other materials such as Teflon and copper that are resistant to transformer oil corrosion can also meet the requirements.

[0069] The test chamber 5 is preferably made of 316 stainless steel, which is resistant to transformer oil corrosion;

[0070] The oil pressure sensor 6 preferably has a test range of 0-1 MPa and supports a pressure sensor with digital signals. The digital signal adopts the ModBus_RTU communication protocol and the RS-485 physical interface;

[0071] The temperature sensor 7 preferably has a test range of 0-150°C, a measurement accuracy of 0.5°C, and a pressure sensor that supports digital signals. The digital signal adopts ModBus_RTU communication protocol and RS-485 physical interface;

[0072] The seal sample 9 preferably uses an O-ring, other rubber strips and special-shaped parts can also meet the requirements

[0073] The oil storage device 11 is a stainless steel oil storage tank with a preferred volume of 5L;

[0074] The control terminal 14 includes a laptop computer, an industrial computer, etc., and is preferably used in conjunction with an industrial computer with rich interfaces.

[0075] The second aspect of the present invention discloses a method for testing aging of seals under the combined action of multiple stresses, using the above-mentioned device, comprising the following steps:

[0076] S1. Input the variable pressure oil into the test chamber 5 until the oil pressure reaches the preset value;

[0077] S2, the heater heats the test cavity 5 until the temperature reaches a preset value;

[0078] S3, the vibrator starts according to the preset vibration value;

[0079] S4. When the temperature, oil pressure and vibration parameters in the test cavity 5 reach the preset values ​​for a predetermined time, the sealing component sample 9 is taken out.

[0080] It can be understood that the above steps accelerate the aging process of the transformer seal under the combined effects of heat, mechanical vibration and oil pressure.

[0081] In a more specific embodiment, in the above steps S1-S4, if the oil pressure in the test chamber 5 is higher than the preset oil pressure value, the transformer oil is output from the test chamber until the oil pressure reaches the preset oil pressure value; and / or if the temperature in the test chamber is higher than the preset temperature value, the heating temperature of the heater is adjusted until the preset temperature value is reached.

[0082] It can be understood that the temperature and oil pressure of this embodiment are controllable and adjustable, which achieves: the simulated test conditions are closer to the actual operating conditions; overcomes the problem that the temperature, oil pressure and mechanical vibration in the test chamber will also affect each other; ensures the safe conduct of the aging test; accurately controls the temperature, oil pressure and vibration parameters in the test chamber 5 to maintain at the preset values, ensures the accuracy of the test conditions and thus obtains accurate test results for the seals, provides a basis for accurately estimating the service life of the seals, and realizes both control and improvement of maintenance efficiency, and avoids the waste of resources caused by frequent replacement of seals.

[0083] In a more specific embodiment, step S4 further includes:

[0084] S41, when the temperature of the test chamber is maintained for a first preset time, turning off the heater to keep the temperature of the test chamber in a cooling state;

[0085] S42, when the cooling state of the test cavity reaches a second preset time, restarting the heater to heat the test cavity to a preset temperature value;

[0086] S43. Repeat steps S41 and S42 until the sealing member sample is taken out.

[0087] It can be understood that, unlike the existing accelerated aging test method for seals at a constant temperature, the accelerated aging test method proposed in the present invention simulates the thermal cycle process of heating and cooling of seals during actual operation of the transformer, which is closer to the actual operating conditions.

[0088] See Figure 2 In some more specific embodiments, a seal aging test method under multiple combined stresses is provided.

[0089] (1) The control terminal sends an analog signal command through the data bus 13 to start the solenoid valve 2;

[0090] (2) The control terminal 14 sends an analog signal instruction through the data bus 13 to control the electromagnetic pump 3, and uses the electromagnetic pump 3 to drive the transformer oil into the test cavity 5;

[0091] (3) The control terminal 14 communicates with the oil pressure sensor 6 via the data bus 13 to monitor the oil pressure inside the test chamber 5;

[0092] (4) When the oil pressure inside the test chamber 5 reaches the predetermined oil pressure, the control terminal 14 issues a command to close the solenoid valve 2 and the solenoid pump 3 in sequence; if the oil pressure sensor 6 detects that the oil pressure inside the test chamber 5 is higher than the predetermined oil pressure, the control terminal 14 issues a command to control the oil storage device 11 to extract transformer oil from the test chamber 5, thereby reducing the oil pressure inside the test chamber 5 until it reaches the predetermined oil pressure;

[0093] (5) The control terminal 14 communicates with the temperature sensor 7 via the data bus 13 to monitor the temperature in the test chamber 5;

[0094] (6) Simulate the load variation and oil temperature variation of the transformer in actual operation (see Figure 3 ), a heating and cooling process is presented within a 24-hour load cycle, and a control terminal 14 is used to issue a command to control the electromagnetic heating coil 8 to heat for a predetermined time tr and stop heating for a time td, thereby realizing a cycle of rising and falling of the transformer oil temperature;

[0095] It is understandable that the temperature of the transformer in actual operation changes periodically with the power load. During the daytime peak power consumption and the higher ambient temperature, the internal temperature of the transformer is at a high temperature; at night, the temperature follows the power consumption valley and the lower ambient temperature, and the internal temperature of the transformer is at a relatively low temperature. Under such temperature cycle conditions, the seal will undergo cyclic alternating compression deformation. This embodiment considers a temperature cycle within 24 hours of a natural day (Tr+Td=24 hours), which is closer to the actual working conditions and is suitable for transformer seals operating in various regions, not just seals in plateau areas. The temperature loading conditions proposed in this embodiment are a gradual heating and natural cooling process, which reflects the actual thermal stress that the seal can withstand.

[0096] (7) The control terminal 14 communicates with the vibration test bench 10 to control the vibration test bench 10 to operate according to predetermined vibration characteristics, simulating the vibration frequency and amplitude to which the seal is subjected during actual operation of the transformer;

[0097] (8) When the temperature, vibration and oil pressure in the test cavity 5 reach the preset conditions, the seal in the test cavity 5 is kept under the three stress conditions of heat, vibration and oil pressure for accelerated aging for a predetermined time, and the seal sample is taken out;

[0098] (9) Carry out performance testing of seals after aging, test the compression permanent deformation, quality, Shore hardness and other parameters of the seals, and evaluate the degree of aging of the seals;

[0099] (10) The experiment ends.

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transformer seal aging test device under multiple stress combined action, characterized in that: include: Test chamber, heater, vibrator, oil feeder and sealing specimen fixing structure, The sealing sample fixing structure is arranged inside the test cavity. The test cavity is connected to the heater, the vibrator and the oil feeder respectively. The heater is used to heat the test cavity, the vibrator is used to vibrate the test cavity, and the oil feeder is used to feed transformer oil into the test cavity to generate oil pressure on the sealing component sample.

2. The aging test device for transformer seals under multiple combined stresses according to claim 1 is characterized in that: It also includes an oil pressure measuring and controlling device, which is connected to the test cavity and the oil transfer device respectively. The oil pressure measuring and controlling device is used to obtain the oil pressure value in the test cavity and control the oil transfer device to output or input transformer oil according to the oil pressure value so that the oil pressure in the test cavity reaches a preset oil pressure value.

3. A transformer seal aging test device under multiple stress combined action according to claim 1 or 2, characterized in that: It also includes a temperature controller, which is connected to the test cavity and the heater respectively. The temperature controller is used to obtain the temperature value in the test cavity and control the working state of the heater according to the temperature value so that the temperature of the test cavity reaches a preset temperature value.

4. The aging test device for transformer seals under multiple combined stresses according to claim 1 is characterized in that: The heater is an electromagnetic heating coil, and the electromagnetic heating coil is equidistantly arranged outside the test cavity.

5. The aging test device for transformer seals under multiple combined stresses according to claim 1 is characterized in that: The sealing component sample fixing structure includes a groove arranged at the bottom of the test cavity, and the groove is used for placing the sealing component sample.

6. The aging test device for transformer seals under multiple combined stresses according to claim 1 is characterized in that: The vibrator is a vibration test bench, and the vibration test bench is arranged at the bottom of the test cavity.

7. The aging test device for transformer seals under multiple combined stresses according to claim 1 is characterized in that: The oil delivery device includes an oil inlet pipe and an oil outlet pipe, and the oil inlet pipe and the oil outlet pipe are both connected to the test cavity.

8. A transformer seal aging test method under multiple stress combined action based on the device of claim 1, characterized in that: The steps include: S1. Input transformer oil into the test chamber until the oil pressure reaches a preset value; S2, the heater heats the test cavity until the temperature reaches a preset value; S3, the vibrator is started according to the preset vibration value; S4. When the temperature, oil pressure and vibration parameters in the test cavity reach preset values ​​for a predetermined time, remove the sealing component sample.

9. The aging test method for transformer seals under multiple combined stresses according to claim 8, characterized in that: include: If the oil pressure in the test cavity is higher than the preset oil pressure value, outputting the variable pressure oil from the test cavity until the preset oil pressure value is reached; And / or if the temperature in the test chamber is higher than the preset temperature value, adjusting the heating temperature of the heater until the preset temperature value is reached.

10. A transformer seal aging test method under multiple combined stresses according to claim 8 or 9, characterized in that: The step S4 further includes: S41, when the test cavity maintains the preset temperature value for a first preset time, turning off the heater to keep the temperature of the test cavity in a cooling state; S42, when the cooling state of the test cavity is maintained for a second preset time, restarting the heater to heat the test cavity until the temperature reaches the preset value; S43. Repeat steps S41 and S42 until the sealing member sample is taken out.

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