Pre-aging device for alternating current and direct current voltage breakdown test of oil paper of converter transformer

Abstract

The invention relates to the technical field of converter transformers, and particularly discloses a pre-aging device for a converter transformer oil paper alternating current and direct current voltage breakdown test, which comprises a high-temperature drying oven, a pre-aging device, a pre-aging device and a pre-aging device, and is characterized in that a bearing seat is arranged on the bottom wall of the high-temperature drying oven; the box body is detachably mounted in the bearing seat, a sealing cover is arranged at the top end of the box body, an I-shaped frame is arranged at the top end of the sealing cover, and a plurality of vertical rods are arranged between the I-shaped frame and the sealing cover; the driving assembly is mounted in the high-temperature drying oven; the vibrating clamp is used for clamping oiled paper; the vibration type clamp is connected to the bottom end of the I-shaped frame through the vibration type clamp; wherein the high-temperature oven provides a controllable, uniform and reproducible thermal stress environment for the oiled paper. According to the invention, continuous and stable mechanical vibration is applied to the oil paper sample in a high-temperature insulating oil environment, the actual operation condition of the transformer is effectively simulated, and the reliability of a performance test result after pre-aging is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of converter transformers, in particular to a pre-aging device for oil-paper AC / DC voltage breakdown test of a converter transformer. BACKGROUND

[0002] As an efficient and reliable power transmission method, high-voltage direct current (HVDC) transmission technology has been widely used in power systems. Converter transformers, as the core equipment connecting AC and DC systems, bear the key functions of power conversion, electrical isolation and voltage regulation. In the ultra-high voltage (UHV) transmission project, due to long transmission distance and complex environment, converter transformers and their oil-paper insulation systems are subjected to extreme electrical and thermal stresses in AC / DC systems. A deep understanding of the performance of oil-paper insulation can help design more durable insulation systems, slow down the aging process, prevent early damage due to degradation of insulation performance, and thus prolong the service life of converter transformers and related power equipment.

[0003] Currently, when using the laboratory pre-aging device for oil-paper insulation of a converter transformer, the following problems exist:

[0004] 1. The pre-aging device usually uses a single thermal aging method, i.e., the oil-paper sample is placed in an oven for static heating, ignoring the fact that the winding and insulation structure of the transformer are subjected to continuous mechanical vibration caused by electromagnetic force during actual operation. The aging mode of thermal and vibration stresses is disconnected, resulting in a large deviation between the aging mechanism in the laboratory and the degradation mechanism of the insulation material in the real equipment. The performance test results after pre-aging cannot truly reflect the long-term operation reliability of the oil-paper insulation.

[0005] 2. Some pre-aging devices attempt to simply mechanically superimpose a vibration table, but the strong excitation of the vibration table will be transmitted to the entire oven structure and the internal oil box through rigid connection, causing uncontrollable structural resonance, which cannot guarantee the consistency of long-term test conditions and data repeatability, and may even cause equipment damage due to resonance. SUMMARY

[0006] To solve the above problems in the prior art, the present application provides a pre-aging device for oil-paper AC / DC voltage breakdown test of a converter transformer, which can solve the problems raised in the background art.

[0007] The object of the present application can be achieved by the following technical solutions:

[0008] A pre-aging device for oil-paper AC / DC voltage breakdown test of a converter transformer, comprising:

[0009] A high-temperature oven, the bottom wall of the high-temperature oven is provided with a bearing seat;

[0010] A box body for containing insulating oil, which is detachably mounted in a bearing seat, and a sealing cover arranged at the top end of the box body, and a work frame arranged at the top end of the sealing cover, and a plurality of vertical rods arranged between the work frame and the sealing cover;

[0011] A driving assembly mounted in a high-temperature oven;

[0012] A vibrating clamp for clamping oil paper;

[0013] A vibration isolation assembly, and the vibrating clamp is connected to the bottom end of the work frame through the vibrating clamp;

[0014] Wherein, the high-temperature oven provides a controllable, uniform and reproducible thermal stress environment for the oil paper, the driving assembly drives the sealing cover to perform opening or closing action, and the vibrating clamp continuously applies mechanical vibration to the oil paper in the insulating oil to simulate the electromagnetic vibration stress in the operation of the transformer.

[0015] Preferably, the inner wall of the box body is provided with a plurality of partitions, the partitions are arranged at intervals with the bottom wall of the box body to form a bottom communication space, and the top edge of the partition is coplanar with the top edge of the box body.

[0016] Preferably, the bottom end of the sealing cover is provided with a plurality of sealing lips, and the sealing lips of the sealing cover are matched with the ports of the box body.

[0017] Preferably, the driving assembly comprises an electric push rod, the electric push rod is arranged on the top wall of the high-temperature oven through a mounting seat, the output shaft end of the electric push rod is fixedly connected with the top end of the work frame through a fastener, and the top wall of the high-temperature oven is provided with a U-shaped frame, the horizontal section of the U-shaped frame is penetrated and slidably installed with two limiting rods, and the bottom end of the limiting rod is fixedly connected with the top end of the work frame.

[0018] Preferably, a shaft sleeve is arranged in the horizontal section through hole of the U-shaped frame, and the shaft sleeve is slidably sleeved with the limiting rod.

[0019] Preferably, the vibrating clamp comprises a horizontal plate, a plurality of support plates are fixedly connected with the horizontal plate through a rod body at the bottom end of the horizontal plate, the rod body at the bottom end of the horizontal plate is penetrated and slidably connected with the sealing cover, two electric clamping jaws for clamping oil paper are arranged at the bottom end of the support plate, and a vibrator is arranged at the top end of the horizontal plate.

[0020] Preferably, a sealing sleeve is arranged in the through hole of the sealing cover, and the rod body at the bottom end of the horizontal plate is matched with the sealing sleeve.

[0021] Preferably, the vibration isolation assembly comprises a plurality of elastic sheets, the plurality of elastic sheets are mounted between the work frame and the horizontal plate, a plurality of tension springs are arranged between the horizontal plate and the work frame, and a plurality of dampers are arranged between the horizontal plate and the work frame.

[0022] Preferably, the cross plate and the I-beam frame are rotatably connected to the spring sheet via rods.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. By setting up drive components and vibrating clamps, the high-temperature oven provides a constant high-temperature environment, so that the insulating oil in the box and the oil paper sample immersed in it are subjected to continuous thermal stress. At the same time, the vibrator is started, and the mechanical vibration of a specific frequency and amplitude is transmitted to the electric gripper and the oil paper sample it holds through the horizontal plate and support plate, accurately simulating the electromagnetic vibration during operation.

[0025] The beneficial effects are: it enables the application of continuous and stable mechanical vibration to the oil-paper sample in a high-temperature insulating oil environment, effectively simulating the actual operating conditions of the transformer and improving the reliability of the performance test results after pre-aging.

[0026] 2. By setting up vibration isolation components, the spring provides the main static support stiffness, and the tension spring provides flexible buffering. Together, they attenuate the transmission of vibration to the jig. The damper efficiently dissipates vibration energy and suppresses resonance, ensuring that the vibration waveform applied to the test specimen is pure and stable. Vibration isolation components are the key to ensuring effective vibration application without interfering with the environment. The spring provides the main static support stiffness, and the tension spring provides flexible buffering. Together, they attenuate the transmission of vibration to the jig. The damper efficiently dissipates vibration energy and suppresses resonance, ensuring that the vibration waveform applied to the test specimen is pure and stable.

[0027] The beneficial effects that can be obtained are: suppressing the transmission of vibration energy through the positive and negative stiffness composite vibration isolation system, ensuring the purity of the aging test environment and the accuracy of the data.

[0028] 3. By setting up a box body and multiple partitions, the space inside the box is divided by multiple partitions, allowing multiple sets of comparative tests to be carried out simultaneously. The spacing between the partitions and the bottom wall ensures that the insulating oil is connected at the bottom, making the oil temperature highly uniform throughout the box body, and also facilitating the uniform diffusion of aging products;

[0029] The beneficial effects are: improved realism and consistency of the zonal aging test environment for multiple groups of oil paper samples, and improved comparability and reliability of test data. Attached Figure Description

[0030] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0032] Figure 2 This is a structural diagram of the box body and high-temperature oven in this invention;

[0033] Figure 3 This is an installation structure diagram of the box body and the support base in this invention;

[0034] Figure 4 This is a diagram showing the installation structure of the driving component in this invention;

[0035] Figure 5 This is a structural diagram of the sealing cap and support plate in this invention.

[0036] Figure 6 This is a diagram showing the installation structure of the vibration clamp in this invention;

[0037] Figure 7 For the present invention Figure 6 Enlarged view of the structure at point A in the middle.

[0038] Explanation of reference numerals in the attached figures:

[0039] In the picture:

[0040] 1. High-temperature drying oven; 2. Support base;

[0041] 11. Box body; 12. Partition; 13. Sealing cover; 14. I-beam frame; 15. Upright pole;

[0042] 21. Electric push rod; 22. U-shaped frame; 23. Limiting rod; 24. Bushing;

[0043] 31. Horizontal plate; 32. Support plate; 33. Electric gripper; 34. Vibrator; 35. Spring; 36. Tension spring; 37. Damper. Detailed Implementation

[0044] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the specific implementation methods, structures, features, and effects of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and preferred embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this application, it should be understood that the orientation or positional relationship indicated by terms such as "inner" and "outer" are based on the orientation or position shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, a specific orientation structure and operation, and therefore should not be construed as a limitation of this application.

[0046] Reference Figures 1-7The present invention discloses a pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper, comprising: a high-temperature oven 1, and a bearing seat 2 provided on the bottom wall of the high-temperature oven 1;

[0047] The box 11 is used to hold insulating oil. The box 11 can be detachably installed in the support base 2. The inner wall of the box 11 is provided with multiple partitions 12. The partitions 12 are spaced apart from the bottom wall of the box 11 to form a bottom connecting space. The top edge of the partition 12 is coplanar with the top edge of the box 11. The top of the box 11 is provided with a sealing cover 13. The bottom of the sealing cover 13 is provided with multiple sealing lips. The sealing lips of the sealing cover 13 match the port of the box 11. The top of the sealing cover 13 is provided with an I-beam frame 14. Multiple uprights 15 are provided between the I-beam frame 14 and the sealing cover 13.

[0048] To enable the sealing cover 13 to perform opening or closing actions, in this embodiment: a driving assembly is installed inside the high-temperature oven 1. The driving assembly includes an electric push rod 21, which is mounted on the top wall of the high-temperature oven 1 via a mounting base. The output shaft end of the electric push rod 21 is fixedly connected to the top of the I-frame 14 via fasteners. A U-shaped frame 22 is provided on the top wall of the high-temperature oven 1. Two limiting rods 23 are slidably installed through the horizontal section of the U-shaped frame 22. The bottom end of the limiting rod 23 is fixedly connected to the top of the I-frame 14. A bushing 24 is provided in the through hole of the horizontal section of the U-shaped frame 22, and the bushing 24 is slidably sleeved with the limiting rod 23.

[0049] To achieve continuous mechanical vibration of the oil paper in insulating oil and simulate the electromagnetic vibration stress during transformer operation, in this embodiment: a vibrating clamp is used to hold the oil paper. The vibrating clamp includes a horizontal plate 31. Multiple support plates 32 are fixedly connected to the bottom end of the horizontal plate 31 through a rod. The rod at the bottom end of the horizontal plate 31 is slidably connected to the sealing cover 13. A sealing sleeve is provided in the through hole of the sealing cover 13. Two electric grippers 33 for holding the oil paper are provided at the bottom end of the support plate 32. A vibrator 34 is provided at the top end of the horizontal plate 31.

[0050] In order to achieve rigid support and flexible vibration isolation of the I-beam frame 14 and the horizontal plate 31, in this embodiment: the vibration isolation component and the vibrating clamp are connected to the bottom end of the I-beam frame 14 through the vibrating clamp. The vibration isolation component includes springs 35, multiple springs 35 are installed between the I-beam frame 14 and the horizontal plate 31, multiple tension springs 36 are provided between the horizontal plate 31 and the I-beam frame 14, and multiple dampers 37 are provided between the horizontal plate 31 and the I-beam frame 14.

[0051] The working principle of this invention is as follows: By simultaneously applying precisely controlled thermal stress and mechanical vibration to the oil-paper sample in a high-temperature insulating oil environment, the actual operating conditions of the converter transformer are simulated, thereby achieving efficient and realistic accelerated pre-aging.

[0052] Thermal-vibration composite stress loading principle: The core of the device lies in achieving multi-stress synergistic aging. The high-temperature oven 1 provides a constant high-temperature environment, causing the insulating oil in the box 11 and the oil paper sample immersed in it to bear continuous thermal stress. At the same time, the vibrator 34 is activated, and mechanical vibration of a specific frequency and amplitude is transmitted to the electric gripper 33 and the oil paper sample it holds through the horizontal plate 31 and the support plate 32, accurately simulating the electromagnetic vibration during operation.

[0053] Active dynamic sealing and precision guiding principle: The electric push rod 21 drives the jig 14 and the sealing cover 13 to move vertically, realizing the automatic opening and closing of the inlet of the box 11. The limit rod 23 cooperates with the bushing 24 to ensure the precise movement trajectory and prevent deflection. The sealing lip at the bottom of the sealing cover 13 and the port of the box 11 form the main seal, while the rod penetrating the sealing cover 13 and the sealing sleeve form a dynamic seal to ensure no leakage during vibration transmission.

[0054] Flexible vibration isolation and energy dissipation principle: The vibration isolation component is the key to ensuring that vibration is applied effectively without disturbing the environment. The spring 35 provides the main static support stiffness, and the tension spring 36 provides flexible buffering. Together, they attenuate the transmission of vibration to the I-beam frame 14. The damper 37 efficiently dissipates vibration energy, suppresses resonance, and ensures that the vibration waveform applied to the test specimen is pure and stable.

[0055] The principle of zoned aging and oil circuit connection: Multiple partitions 12 inside the box 11 divide the space, allowing multiple sets of comparative tests to be carried out simultaneously. The gap between the partitions 12 and the bottom wall ensures that the insulating oil is connected at the bottom, making the oil temperature in the entire box 11 uniform, and facilitating the uniform diffusion of aging products.

[0056] Operating Procedure: First, the operator injects sufficient insulating oil into the housing 11 to ensure the test sample is completely submerged. The sealing cover 13 is opened via the drive assembly, and multiple oil-paper test samples are placed into different electric grippers 33 and clamped. Next, the electric push rod 21 is activated again to close the sealing cover 13, ensuring the sealing lip is tightly pressed. The high-temperature oven 1 door is then closed. Next, the aging parameters are set on the control system interface: the target temperature and duration of the high-temperature oven 1, and the vibration frequency, amplitude, and mode of the vibrator 34. After confirming the parameters, the aging program is started, and the device begins automatic operation. The high-temperature oven 1 heats to the set temperature and maintains it. The vibrator 34 continuously applies mechanical vibration to the test sample in the oil according to the set program. During the subsequent test cycle of hundreds or even thousands of hours, the vibration isolation assembly continues to operate. Finally, at the end of the test, the system first stops heating and vibration. After the temperature drops to a safe range, the sealing cover 13 is automatically opened, and the operator removes the oil-paper test sample for subsequent operations.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A pre-aging device for AC / DC voltage breakdown testing of converter transformer oil paper, characterized in that, include: High temperature oven (1), the bottom wall of the high temperature oven (1) is provided with a support seat (2); The box (11) is used to hold insulating oil. The box (11) is detachably installed in the support base (2). The top of the box (11) is provided with a sealing cover (13). The top of the sealing cover (13) is provided with an I-shaped frame (14). Multiple uprights (15) are provided between the I-shaped frame (14) and the sealing cover (13). The drive assembly is installed inside the high-temperature oven (1); Vibration clamps are used to hold oil paper. Vibration isolation components, the vibration clamp is connected to the bottom end of the jig (14) through the vibration clamp; The high-temperature oven (1) provides a controllable, uniform and reproducible thermal stress environment to the oil paper, the drive assembly drives the sealing cover (13) to perform opening or closing actions, and the vibrating clamp continuously applies mechanical vibration to the oil paper in the insulating oil to simulate the electromagnetic vibration stress during transformer operation.

2. The pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 1, characterized in that, The inner wall of the box (11) is provided with a plurality of partitions (12), the partitions (12) are spaced apart from the bottom wall of the box (11) to form a bottom connecting space, and the top edge of the partitions (12) is coplanar with the top edge of the box (11).

3. The pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 2, characterized in that, The bottom of the sealing cover (13) is provided with multiple sealing lips, and the sealing lips of the sealing cover (13) are matched with the port of the box body (11).

4. The pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 1, characterized in that, The drive assembly includes an electric push rod (21), which is mounted on the top wall of the high-temperature oven (1) via a mounting base. The output shaft end of the electric push rod (21) is fixedly connected to the top of the I-frame (14) via fasteners. A U-shaped frame (22) is provided on the top wall of the high-temperature oven (1). Two limiting rods (23) are slidably installed through the horizontal section of the U-shaped frame (22). The bottom end of the limiting rod (23) is fixedly connected to the top of the I-frame (14).

5. The pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 4, characterized in that, A bushing (24) is provided in the through hole of the horizontal section of the U-shaped frame (22), and the bushing (24) is slidably sleeved with the limiting rod (23).

6. The pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 1, characterized in that, The vibratory clamp includes a horizontal plate (31), and a plurality of support plates (32) are fixedly connected to the bottom end of the horizontal plate (31) by a rod. The rod at the bottom end of the horizontal plate (31) is connected to the sealing cover (13) through and in a sliding manner. The bottom end of the support plate (32) is provided with two electric grippers (33) for holding oil paper. The top end of the horizontal plate (31) is provided with a vibrator (34).

7. The pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 6, characterized in that, A sealing sleeve is provided in the through hole of the sealing cover (13), and the bottom rod of the horizontal plate (31) matches the sealing sleeve.

8. The pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 6, characterized in that, The vibration isolation assembly includes springs (35), a plurality of springs (35) are installed between the I-beam frame (14) and the cross plate (31), a plurality of tension springs (36) are provided between the cross plate (31) and the I-beam frame (14), and a plurality of dampers (37) are provided between the cross plate (31) and the I-beam frame (14).

9. A pre-aging device for AC / DC voltage breakdown test of converter transformer oil paper according to claim 8, characterized in that, The horizontal plate (31) and the I-beam frame (14) are rotatably connected to the spring piece (35) via rods.

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