Oil-immersed reactor damping and noise reduction method and oil-immersed reactor

Abstract

This invention relates to the field of vibration and noise reduction technology for oil-immersed power equipment, and particularly to a method for vibration and noise reduction of oil-immersed reactors. The method includes: setting an oil-resistant flexible damping layer on the exposed surfaces of the core on both sides corresponding to at least one air gap in the core; setting an oil-resistant elastic support between the lower core clamp and the bottom plate of the oil tank; injecting pre-treated natural ester insulating oil into the oil tank; and configuring an oil flow heat exchange path that matches the viscosity of the natural ester insulating oil. The method and the oil-immersed reactor provided by this invention introduce natural ester insulating oil into a confined gap near the vibration source, allowing it to participate in local vibration energy dissipation. This solves the technical problems that simple external vibration isolation or sound insulation of oil-immersed reactors is insufficient to dissipate vibration energy in the vicinity of the vibration source area near the core air gap, and that direct replacement with high-viscosity natural ester insulating oil may lead to increased temperature rise.

Description

Technical Field

[0001] This invention relates to the field of vibration reduction and noise reduction technology for oil-immersed power equipment, and particularly to a method for vibration reduction and noise reduction of oil-immersed reactors and an oil-immersed reactor. Background Technology

[0002] Oil-immersed reactors are used in power systems for reactive power compensation, current limiting, and filtering. For reactors with segmented air-gap cores, the area near the air gap is subjected to periodic electromagnetic forces during operation, easily generating mechanical vibrations dominated by power frequency harmonics. This vibration is transmitted outward through the core, clamps, insulating oil, and tank walls, forming low-frequency noise. Low-frequency noise attenuates slowly and has strong penetrating power, making it difficult to address with simple external sound insulation in substations, converter stations, and urban perimeter power facilities.

[0003] Existing vibration reduction and noise reduction measures typically focus on the transmission path or sound radiation path. For example, this involves installing vibration isolation pads at the bottom of the equipment, adding a soundproof enclosure to the outside of the oil tank, or reducing vibrations caused by localized loosening by increasing clamping force. These measures have some effect on reducing transmitted vibration, but their effect on local energy dissipation in the vibrating source area near the air gap of the core is limited. Other solutions reduce electromagnetic excitation by changing the core structure, air gap structure, or winding arrangement; however, these solutions involve adjustments to the main electromagnetic structure and have poor adaptability to modifications of existing reactors.

[0004] Oil-immersed reactors commonly use mineral insulating oil as the insulation and cooling medium. Mineral insulating oil has good fluidity, making it suitable for heat exchange cycles, but its low viscosity limits its shear energy dissipation capacity in vibration gaps. Natural ester insulating oil has a higher ignition point, better environmental friendliness, and relatively higher kinematic viscosity. Its higher viscosity provides the basic conditions for participating in fluid damping energy dissipation, but it also leads to increased oil flow resistance and decreased heat exchange capacity. Simply replacing mineral insulating oil with natural ester insulating oil without matching the oil flow heat exchange path poses a risk of increased temperature rise in the reactor. Summary of the Invention

[0005] This invention addresses the technical problems in the prior art where simple external vibration isolation or sound insulation of oil-immersed reactors is insufficient to dissipate vibration energy in the vibrating source region near the air gap of the iron core, and the potential for increased temperature rise after direct replacement with high-viscosity natural ester insulating oil. It provides a vibration reduction and noise reduction method for oil-immersed reactors and an oil-immersed reactor itself.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A vibration reduction and noise reduction method for oil-immersed reactors, applied to oil-immersed reactors with segmented air-gap cores; the method includes: An oil-resistant flexible damping layer is provided on the exposed surfaces of the iron core on both sides corresponding to at least one iron core air gap, and a bonding gap is formed between the oil-resistant flexible damping layer and the corresponding exposed surface of the iron core, which can be immersed in natural ester insulating oil. An oil-resistant elastic support is installed between the lower clamp of the iron core and the bottom plate of the oil tank. The oil-resistant flexible damping layer and the oil-resistant elastic support are located in the vibratory source area near the air gap of the iron core and on the iron core support transmission path, respectively. Inject pre-treated natural ester insulating oil into the oil tank. The natural ester insulating oil fills the inside of the oil tank, the bonding gaps, and the space around the oil-resistant elastic support. Configure an oil flow heat exchange path that matches the viscosity of the natural ester insulating oil. The natural ester insulating oil flows along the oil flow heat exchange path through the heat-generating area inside the oil tank and exchanges heat with the heat dissipation area of ​​the oil tank or an external heat dissipation unit.

[0007] Furthermore, the oil-resistant flexible damping layer is disposed on the exposed side of the adjacent core segment forming the core air gap, and avoids the main magnetic flux working interval of the core air gap.

[0008] Furthermore, the oil-resistant flexible damping layer is made of rubber elastomer or polyurethane elastomer that is resistant to natural ester insulating oil; The thickness of the oil-resistant flexible damping layer is 5mm-20mm; The oil-resistant flexible damping layer covers the exposed surface of the iron core by 10mm-30mm beyond the corresponding air gap boundary of the iron core.

[0009] Furthermore, the gap size of the bonding gap is less than or equal to 1 mm, and the natural ester insulating oil forms an oil film shear damping zone between the exposed surface of the iron core and the oil-resistant flexible damping layer.

[0010] Furthermore, the number, arrangement, and equivalent stiffness of the oil-resistant elastic support components are determined based on the core mass and the 100Hz or 200Hz vibration component during core operation, so that the vibration transmitted from the core to the bottom plate of the oil tank through the lower core clamp is attenuated.

[0011] Furthermore, the kinematic viscosity of natural ester insulating oil at 40°C is 30 mm² / s-35 mm² / s, and its ignition point is not lower than 300°C; Natural ester insulating oil undergoes vacuum dehydration and degassing treatment before being injected into the oil tank. The moisture content after treatment is less than or equal to 50 mg / kg, and the breakdown voltage is greater than or equal to 60 kV.

[0012] Furthermore, the oil flow heat exchange path is formed by increasing the cross-section of the oil passage, setting up oil guiding components, adopting a forced oil circulation unit, or setting up an external heat dissipation unit.

[0013] Furthermore, increasing the flow cross-section of the oil passage includes: For modified oil-immersed reactors, the width of the oil passage before modification will be increased by 20%-50%; For newly manufactured oil-immersed reactors, the oil channel width is increased by 20%-50% relative to the oil channel width suitable for mineral insulating oil; or, At least one longitudinal oil passage is added between the iron core and the winding, between the iron core and the oil tank, and between the winding and the oil tank.

[0014] Furthermore, the oil guiding component is disposed between the iron core and the oil tank. The oil guiding component is used to guide the natural ester insulating oil to flow through the hot spot area of ​​the winding, the area adjacent to the air gap of the iron core, or the hot spot area at the top of the oil tank.

[0015] Furthermore, the forced oil circulation unit includes a low-noise oil pump, the flow rate of which is adjusted according to at least one of the top oil temperature rise, winding hot spot temperature, or tank wall temperature. An external heat dissipation unit is used to increase the external heat dissipation area of ​​the fuel tank.

[0016] Furthermore, it also includes: Collect at least one of the following: oil tank wall vibration signal, iron core vibration signal, top oil temperature signal, or winding hot spot temperature signal; When the collected signal exceeds the corresponding preset threshold, the oil flow rate is adjusted if the oil flow heat exchange path includes an adjustable oil flow drive component, or an alarm signal is output.

[0017] The present invention also provides an oil-immersed reactor for implementing a method for vibration reduction and noise reduction of an oil-immersed reactor, comprising: tank; The iron core is installed inside the oil tank and has segmented air gaps. A winding, fitted over at least a portion of the iron core; An oil-resistant flexible damping layer is disposed on the exposed surfaces of the iron core on both sides corresponding to at least one iron core air gap, and a fitting gap is formed between the oil-resistant flexible damping layer and the corresponding exposed iron core surface. An oil-resistant elastic support is installed between the lower clamp of the iron core and the bottom plate of the oil tank; Natural ester insulating oil is used to fill the interior of the oil tank, the gaps between components, and the space around the oil-resistant elastic support; and The oil flow heat exchange structure is matched with the viscosity of the natural ester insulating oil. The oil flow heat exchange structure is used to form an oil flow heat exchange path for the natural ester insulating oil to flow through the heat-generating area inside the oil tank and exchange heat with the heat dissipation area of ​​the oil tank or an external heat dissipation unit. The bonding gap is used to form a shear flow energy dissipation zone for natural ester insulating oil when vibration occurs at the air gap of the iron core. The oil-resistant flexible damping layer and the oil-resistant elastic support are used to attenuate the vibration in the area adjacent to the air gap of the iron core and the vibration transmitted from the iron core to the bottom plate of the oil tank, respectively.

[0018] Furthermore, the oil flow heat exchange structure includes at least one of widened oil passages, oil guiding components, forced oil circulation units, or external heat dissipation units.

[0019] Furthermore, the oil-immersed reactor also includes a vibration sensor, a temperature sensor, a signal acquisition module, a controller, a cooling flow regulation module, and an alarm module; Vibration sensors are installed on the outside of the tank wall or at the iron core clamp. The temperature sensor is located in the upper oil layer of the oil tank or at the hot spot of the winding. The signal acquisition module has a first signal input terminal, a second signal input terminal, and a signal acquisition output terminal. The first signal input terminal is connected to the vibration sensor, the second signal input terminal is connected to the temperature sensor, and the signal acquisition output terminal is connected to the acquisition input terminal of the controller. The controller has a flow control output terminal and an alarm output terminal. The flow control output terminal is connected to the control input terminal of the cooling flow regulation module, and the alarm output terminal is connected to the alarm input terminal of the alarm module. The cooling flow rate adjustment module is connected to the oil circulation pipeline of the oil flow heat exchange structure, and the alarm module is set in the local control box of the oil-immersed reactor, or the alarm module is connected to the background monitoring system.

[0020] Compared with the prior art, the method for vibration reduction and noise reduction of oil-immersed reactors and the oil-immersed reactors provided by the present invention have at least the following beneficial effects: The present invention provides a method for vibration reduction and noise reduction of an oil-immersed reactor, and an oil-immersed reactor in which an oil-resistant flexible damping layer is arranged in the vibrating source region near the air gap of the iron core, and a bonding gap impregnated with natural ester insulating oil is formed between the oil-resistant flexible damping layer and the exposed surface of the iron core. When the reactor is running, the micro-vibration near the air gap of the iron core causes a velocity gradient in the oil in the bonding gap. Natural ester insulating oil has a higher viscosity than mineral oil, making it easier to form shear energy dissipation in this gap. This structure does not simply use natural ester insulating oil to replace mineral oil, but rather introduces natural ester insulating oil into the confined gap near the vibration source, allowing it to participate in the local vibration energy dissipation.

[0021] The present invention provides a method for vibration reduction and noise reduction of an oil-immersed reactor, and an oil-immersed reactor in which an oil-resistant elastic support is installed between the lower clamp of the iron core and the bottom plate of the oil tank, thereby creating a graded treatment of damping near the air gap of the iron core and vibration isolation at the bottom of the iron core. The vibration at the vibration source is first locally attenuated in the area near the air gap, and the mechanical vibration transmitted to the bottom plate and wall of the oil tank is further reduced through the oil-resistant elastic support along the iron core support path. This treatment method can reduce the problem of insufficient local energy dissipation at the vibration source due to single external vibration isolation.

[0022] The present invention provides a vibration reduction and noise reduction method for oil-immersed reactors and an oil-immersed reactor in which an oil flow heat exchange path is configured to match the viscosity of natural ester insulating oil. This allows the natural ester insulating oil to participate in fluid damping energy dissipation while still meeting the temperature rise control requirements of the oil-immersed reactor. By adapting the flow resistance and heat exchange capacity of high-viscosity oil to the oil flow heat exchange path, the risk of hot spot temperature rise that may be caused by simply replacing the insulating oil with natural ester can be reduced. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the oil-immersed reactor in an embodiment of the present invention; Figure 2 This is a schematic diagram of the vibration and temperature monitoring and control structure in an embodiment of the present invention; Figure 3 This is a comparison diagram of the kinematic viscosity of mineral insulating oil and natural ester insulating oil in the embodiments of the present invention; Figure 4 This is a comparison chart of the top oil temperature rise and vibration reduction values ​​under different oil passage width increases and heat dissipation adaptation conditions in the embodiments of the present invention. Figure 5 This is a comparison diagram of vibration acceleration levels between the embodiments and comparative examples in the present invention. Figure 6 The diagram shows the temperature rise process of some embodiments and comparative examples in the implementation of this invention; Figure 7 This is a graph showing the viscosity change of natural ester insulating oil after thermal cycling in an embodiment of the present invention.

[0024] Among them, 1-oil-immersed reactor; 10-oil tank; 20-iron core; 21-iron core air gap; 22-iron core lower clamp; 30-winding; 40-oil-resistant flexible damping layer; 50-oil-resistant elastic support; 60-natural ester insulating oil; 70-oil flow heat exchange structure; 72-oil guiding component; 81-vibration sensor; 82-temperature sensor; 83-signal acquisition module; 84-controller; 85-cooling flow regulation module; 86-alarm module. Detailed Implementation

[0025] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the invention will be thorough and complete.

[0026] The embodiments of the present invention will now be described with reference to the accompanying drawings. The following description uses an oil-immersed reactor with a segmented air-gap core as an example to illustrate how the present invention integrates local damping in the air-gap adjoining region, elastic vibration isolation of the core support path, fluid shear energy dissipation of natural ester insulating oil, and heat transfer adaptation of high-viscosity oil into the same vibration reduction and noise reduction system without changing the air-gap width of the core and the arrangement of the winding body. The following embodiments are used to explain the technical solution of the present invention and are not intended to limit the scope of protection of the present invention.

[0027] like Figure 1 As shown, the oil-immersed reactor includes an oil tank 10, an iron core 20, and a winding 30. The iron core 20 is disposed inside the oil tank 10, and the winding 30 is sleeved on at least a portion of the iron core 20. The iron core 20 has multiple segmented air gaps 21. During reactor operation, the area near the air gaps 21 is subjected to alternating electromagnetic forces, making the region adjacent to the air gaps 21 a location where vibration energy is relatively concentrated. This vibration is transmitted outward through the iron core 20, the lower clamp 22, the insulating oil, and the oil tank 10, causing vibration of the oil tank wall and generating radiated noise.

[0028] In response to the aforementioned vibration transmission characteristics, this invention does not focus on the sound insulation covering of the oil tank 10, but instead implements multi-stage energy dissipation in the early stages of vibration formation and transmission. Specifically, an oil-resistant flexible damping layer 40 is arranged in the vibratory source region near the air gap 21 of the iron core, an oil-resistant elastic support 50 is arranged between the lower clamp 22 of the iron core and the bottom plate of the oil tank, and natural ester insulating oil 60 fills the interior of the oil tank 10 and enters the bonding gap between the oil-resistant flexible damping layer 40 and the iron core 20. Before the vibration generated at the air gap 21 of the iron core is transmitted to the oil tank 10, it undergoes local solid damping, oil film shear damping, and support vibration isolation treatment successively.

[0029] When retrofitting an existing oil-immersed reactor, the original insulating oil is usually drained first. The interior of the oil tank 10, the core 20, the lower core clamp 22, the winding 30, and the original oil channels are then inspected. Next, the oil-resistant flexible damping layer 40 and the oil-resistant elastic support 50 are installed. The oil flow heat exchange structure 70 can be configured before oil injection or can be locally adjusted in conjunction with the existing oil channels and radiator. After completing the above structural treatment, natural ester insulating oil 60, which has undergone insulation pretreatment, is injected into the oil tank 10, filling the interior of the oil tank 10, the fitting gaps, and the space around the oil-resistant elastic support 50.

[0030] like Figure 1As shown, an oil-resistant flexible damping layer 40 is disposed on the exposed surfaces of the iron core on both sides corresponding to at least one iron core air gap 21. Here, the exposed iron core surface refers to the iron core surface area close to the iron core air gap 21 and capable of being attached to or adjacent to the damping structure. The oil-resistant flexible damping layer 40 does not enter the main magnetic flux working interval of the iron core air gap 21; its purpose is to dampen the area adjacent to the iron core air gap 21, rather than to change the magnetic circuit structure of the iron core 20. Therefore, the arrangement of the oil-resistant flexible damping layer 40 should avoid the effective air gap space of the iron core air gap 21, keeping the width of the iron core air gap 21 and the arrangement of the winding 30 unchanged.

[0031] A fitting gap is formed between the oil-resistant flexible damping layer 40 and the exposed surface of the iron core. This fitting gap is not a large-sized oil channel for the main oil flow circulation, but rather a confined oil film space for the natural ester insulating oil 60 to enter. The fitting gap does not leave the oil-resistant flexible damping layer 40 in a loose state from the exposed surface of the iron core; rather, after the oil-resistant flexible damping layer 40 is fixedly installed, it forms a thin oil film space formed by at least one of the following: the micro-roughness of the surface of the oil-resistant flexible damping layer 40, local support protrusions, spacer pads, or pre-set microgrooves. The oil-resistant flexible damping layer 40 is still held in a predetermined position on the exposed surface of the iron core by clamping, bonding, pressing, or limiting components, thus balancing the entry of oil into the fitting gap with the installation stability of the damping layer.

[0032] During reactor operation, micro-vibrations occur near the air gap 21 of the core, creating relative fretting between the exposed surface of the core and the oil-resistant flexible damping layer 40. Consequently, the natural ester insulating oil 60 located in the bonding gap undergoes shear flow. Because the viscosity of the natural ester insulating oil 60 is higher than that of commonly used mineral insulating oil, the oil film in the bonding gap can provide viscous shear damping under relatively fretting conditions, converting some of the mechanical vibration energy into energy dissipated through internal friction in the oil. Simultaneously, the oil-resistant flexible damping layer 40 itself undergoes elastic deformation and material hysteresis energy dissipation, thus forming a localized energy-dissipating structure in the region adjacent to the air gap 21 of the core, combining solid damping and fluid damping.

[0033] The oil-resistant flexible damping layer 40 can be made of rubber elastomer or polyurethane elastomer resistant to natural ester insulating oil. For example, nitrile rubber, fluororubber, or oil-resistant polyurethane elastomer can be selected. Material selection must consider dimensional stability, thermal aging performance, insulation performance, and mechanical damping performance after immersion in natural ester insulating oil. The thickness of the oil-resistant flexible damping layer 40 can be 5mm-20mm, and its coverage area can extend 10mm-30mm beyond the boundary of the corresponding iron core air gap 21. This size range allows vibrations near the edge of the iron core air gap 21 to enter the damping coverage area, while avoiding excessively thick damping layers that would restrict the internal arrangement space of the oil tank 10.

[0034] The size of the bonding gap affects the oil film shear energy dissipation effect. When the bonding gap is too large, the oil is closer to a free-flowing state, and the restricted shear effect is weakened; when the bonding gap is too small, it is difficult to guarantee the oil immersion and assembly consistency. In one embodiment, the bonding gap size is less than or equal to 1 mm, so that the natural ester insulating oil 60 can form an oil film shear damping zone between the exposed surface of the iron core and the oil-resistant flexible damping layer 40. This bonding gap is intended to form a thin oil film, does not change the magnetic circuit spacing of the iron core air gap 21 itself, and is not used as the main circulating oil channel of the reactor.

[0035] After the local energy dissipation is completed in the area adjacent to the air gap 21 of the iron core, residual vibration may still be transmitted to the bottom plate of the oil tank through the iron core 20 and the lower clamping member 22 of the iron core. Figure 1 As shown, this invention provides an oil-resistant elastic support 50 between the lower clamp 22 of the iron core and the bottom plate of the oil tank. The oil-resistant elastic support 50 is located on the support transmission path of the iron core 20, and weakens the rigid vibration transmission from the iron core 20 to the oil tank 10 through elastic deformation and material damping. Compared to simply providing vibration isolation pads outside the oil tank 10, the oil-resistant elastic support 50 is closer to the force transmission path of the iron core 20, enabling attenuation of vibrations before they reach the tank wall.

[0036] The oil-resistant elastic support 50 is made of an elastomer material resistant to natural ester insulating oil. The number, installation position, and equivalent stiffness of the oil-resistant elastic support 50 can be determined based on the mass of the core 20, the stress position of the lower core clamp 22, and the main vibration frequency components during reactor operation. For power frequency reactors, the 100Hz and 200Hz components are usually the vibration components that need to be addressed. By matching the equivalent stiffness of the oil-resistant elastic support 50 with the mass of the core 20 and the target frequency components, the vibration transmitted from the core 20 to the tank bottom plate via the lower core clamp 22 can be reduced. Multiple oil-resistant elastic supports 50 can be arranged at intervals along the main load-bearing positions of the lower core clamp 22 to balance support stability and vibration isolation.

[0037] In this invention, the natural ester insulating oil 60 functions as an insulating medium, a cooling medium, and a fluid damping medium. Before being injected into the oil tank 10, the natural ester insulating oil 60 undergoes vacuum dehydration and degassing treatment to meet the insulation operation requirements of the oil-immersed reactor. In one embodiment, the natural ester insulating oil 60 has a kinematic viscosity of 30 mm² / s-35 mm² / s at 40°C, an ignition point not lower than 300°C, and after pretreatment, a moisture content less than or equal to 50 mg / kg and a breakdown voltage greater than or equal to 60 kV.

[0038] like Figure 3As shown, taking one sample as an example, the kinematic viscosity of natural ester insulating oil 60 is higher than that of mineral insulating oil at the test temperatures illustrated. For example, at the low-temperature test point, the kinematic viscosity of natural ester insulating oil 60 is approximately 85 mm² / s, while that of mineral insulating oil is approximately 24.8 mm² / s; at test points near the operating temperature range, the kinematic viscosity of natural ester insulating oil 60 is approximately 33.9 mm² / s, while that of mineral insulating oil is approximately 9.55 mm² / s; at higher temperature test points, the kinematic viscosity of both natural ester insulating oil 60 and mineral insulating oil decreases, but natural ester insulating oil 60 still maintains a higher viscosity. These viscosity differences indicate that natural ester insulating oil 60 can provide stronger viscous shear damping in the bonding gap, but it also generates greater flow resistance within the oil channels. If only mineral insulating oil is replaced with natural ester insulating oil 60, although some fluid damping effect may be obtained, the risk of temperature rise will increase simultaneously. This invention utilizes its viscosity characteristics for vibration reduction while configuring an oil flow heat exchange path that matches its viscosity.

[0039] The oil flow heat exchange path is formed by the oil flow heat exchange structure 70. The oil flow heat exchange structure 70 allows the natural ester insulating oil 60 to flow through the main heat-generating areas within the oil tank 10, exchanging heat with the oil tank's heat dissipation area or an external heat dissipation unit, thereby transferring heat to the oil tank 10 or external heat dissipation components. The oil flow heat exchange structure 70 may include at least one of widened oil channels, oil guiding components 72, forced oil circulation units, or external heat dissipation units. For oil-immersed reactors of different capacities, voltage levels, and internal structures, the above structures may be used individually or in combination.

[0040] Widening the oil channels reduces the flow resistance of natural ester insulating oil 60 within them. For modified oil-immersed reactors, the original oil channel width can be increased by 20%-50%; for newly manufactured oil-immersed reactors, the oil channel width can be increased by 20%-50% relative to the oil channel width suitable for mineral insulating oil; additional longitudinal oil channels can be added at least once between the core 20 and winding 30, between the core 20 and oil tank 10, and between the winding 30 and oil tank 10. For newly manufactured reactors, widening the oil channels can be achieved during the design phase; for reactors already in operation, widening the oil channels can be achieved by replacing oil channel pads, adjusting local insulation supports, or increasing longitudinal flow space.

[0041] like Figure 4 As shown, the temperature rise and vibration reduction of the top oil layer differ under different increases in oil passage width and different heat dissipation adaptation conditions. Figure 4The 0% oil channel increase corresponds to the case where only the natural ester insulating oil is replaced without configuring an oil flow heat exchange structure. In this case, the top oil temperature rise is high, and the vibration reduction value is small. The 12.5% ​​oil channel increase corresponds to the case of insufficient heat dissipation compensation. Although the vibration reduction value is high due to the configuration of a graded damping structure, the top oil temperature rise is still relatively high. The 25%-50% oil channel increase corresponds to the heat dissipation adaptation conditions in the embodiment. The top oil temperature rise can be controlled at a low level while maintaining a good vibration reduction effect. While a 100% oil channel increase can meet the temperature rise requirements, it will occupy space for insulation and structural layout and may change the oil flow distribution. Therefore, the oil channel width increase should be determined comprehensively based on the original oil circuit structure, insulation distance, hot spot location, and damping structure layout, preferably controlled within the range of 20%-50%. It should be noted that... Figure 4 The vibration reduction value is not determined solely by the width of the oil channel; it is also affected by factors such as the natural ester insulating oil 60, the oil-resistant flexible damping layer 40, the bonding gap, and the oil-resistant elastic support 50.

[0042] The oil guiding component 72 can be disposed between the iron core 20 and the oil tank 10 to guide the natural ester insulating oil 60 through the hot spot area of ​​the winding, the area adjacent to the air gap 21 of the iron core, or the hot spot area at the top of the oil tank. The oil guiding component 72 can reduce oil flow short circuits, allowing the heat exchange oil to flow through the main heat-generating areas and the damping energy-dissipating areas. For the small amount of energy-dissipating heat generated near the bonding gap and the oil-resistant flexible damping layer 40, it can also be carried away by the adjacent oil flow, thereby avoiding abnormal local temperature rise.

[0043] The forced oil circulation unit may include a low-noise oil pump and connecting piping. The low-noise oil pump drives the natural ester insulating oil 60 to circulate between the oil tank 10 and external heat exchange components. The low-noise oil pump can operate at a constant flow rate or with flow rate regulation based on temperature feedback. When using feedback regulation, the oil pump flow rate can be determined based on at least one of the top oil temperature rise, winding hot spot temperature, or oil tank wall temperature. When the load is low or the temperature rise is low, the oil pump operates at a lower flow rate to reduce additional noise and energy consumption; when the temperature rise approaches the set control target, the oil pump increases the flow rate to enhance heat exchange capacity.

[0044] External heat dissipation units are used to increase the external heat dissipation area of ​​oil-immersed reactors. These units can include plate-type radiators, finned radiators, or oil-air coolers. When used in conjunction with a forced oil circulation unit, the natural ester insulating oil 60 flows out of the oil tank 10, enters the external heat dissipation unit for heat exchange, and then returns to the oil tank 10. External heat dissipation units can also be used in natural oil circulation structures to compensate for the reduced convective heat transfer capacity caused by the high viscosity of the natural ester insulating oil by increasing the heat dissipation area.

[0045] like Figure 2As shown, the oil-immersed reactor can also be configured with a vibration and temperature monitoring and control structure. This structure, serving as an operation, maintenance, and safety protection solution, includes a vibration sensor 81, a temperature sensor 82, a signal acquisition module 83, a controller 84, a cooling flow regulation module 85, and an alarm module 86.

[0046] A vibration sensor 81 is disposed on the outer side of the oil tank wall of the oil tank 10 or at the iron core clamp. In one embodiment, the vibration sensor 81 is an accelerometer, disposed in the middle region of the outer wall of the oil tank 10, near the iron core 20 on the side wall of the oil tank 10, or at the iron core clamp. A temperature sensor 82 is disposed in the upper oil layer of the oil tank 10 or at a hot spot location of the winding 30. In one embodiment, the temperature sensor 82 includes an oil temperature sensor or a fiber optic temperature sensor, with the oil temperature sensor disposed in the upper oil layer of the oil tank 10 and the fiber optic temperature sensor disposed at a hot spot location of the winding 30.

[0047] The signal acquisition module 83 has a first signal input terminal, a second signal input terminal, and a signal acquisition output terminal. The first signal input terminal is connected to the vibration sensor 81, the second signal input terminal is connected to the temperature sensor 82, and the signal acquisition output terminal is connected to the acquisition input terminal of the controller 84. The signal acquisition module 83 may include a signal conditioning circuit, an analog-to-digital conversion circuit, and an acquisition communication interface. The signal conditioning circuit is connected between the vibration sensor 81, the temperature sensor 82, and the analog-to-digital conversion circuit, and the acquisition communication interface is connected between the analog-to-digital conversion circuit and the controller 84.

[0048] The controller 84 has a data acquisition input terminal, a flow control output terminal, and an alarm output terminal. The data acquisition input terminal is connected to the data acquisition signal output terminal of the signal acquisition module 83, the flow control output terminal is connected to the control input terminal of the cooling flow regulation module 85, and the alarm output terminal is connected to the alarm input terminal of the alarm module 86.

[0049] The cooling flow rate regulating module 85 is connected to the oil circulation pipeline of the oil flow heat exchange structure 70. In one embodiment, the cooling flow rate regulating module 85 includes a frequency converter or an electric regulating valve. The frequency converter is electrically connected to a low-noise oil pump in the forced oil circulation unit, and the electric regulating valve is located on the oil circulation pipeline of the oil flow heat exchange structure 70. An electrical signal connection and an oil circuit connection are formed between the controller 84, the cooling flow rate regulating module 85, and the oil flow heat exchange structure 70.

[0050] The alarm module 86 is installed in the local control box of the oil-immersed reactor, or the alarm module 86 is communicatively connected to the background monitoring system. In one embodiment, the alarm module 86 includes at least one of an audible and visual alarm, a relay output terminal, or a communication alarm interface. The audible and visual alarm is located in the local control box or a visible inspection location; the relay output terminal is connected to the station's protection or monitoring circuit; and the communication alarm interface is connected to the background monitoring system.

[0051] In the aforementioned vibration and temperature monitoring and control structure, the signals collected by the vibration sensor 81 and the temperature sensor 82 are transmitted to the controller 84 via the signal acquisition module 83. The output signal of the controller 84 is then transmitted to the cooling flow regulation module 85 and the alarm module 86, respectively. This structure serves as an auxiliary operation protection structure and is arranged in conjunction with the oil-resistant flexible damping layer 40, the bonding gap 41, the oil-resistant elastic support 50, and the oil flow heat exchange structure 70.

[0052] To verify the effectiveness of the above technical solution, a 110kV oil-immersed shunt reactor is used as a basic prototype for illustration. This prototype has a rated capacity of 40Mvar, and its core 20 adopts a segmented air-gap structure with eight air gaps 21, each with a width of 6mm. The basic prototype originally used #25 mineral insulating oil, with a kinematic viscosity of approximately 9.2mm² / s at 40℃. The natural ester insulating oil 60 is a soybean oil-based natural ester insulating oil, with a kinematic viscosity of approximately 34mm² / s at 40℃, a flash point of approximately 330℃, and a biodegradability rate of approximately 98%.

[0053] In Example 1, a complete vibration reduction and noise reduction modification was performed on the basic prototype. First, the original mineral insulating oil was drained, the inside of the oil tank 10 was cleaned, and the condition of the core 20, the lower core clamp 22, the winding 30, and the original oil channels was inspected. Then, oil-resistant flexible damping layers 40 were installed on the exposed surfaces of the core on both sides corresponding to the eight core air gaps 21. The oil-resistant flexible damping layers 40 are made of nitrile rubber resistant to natural ester insulating oil, with a thickness of 10mm. The coverage area of ​​each oil-resistant flexible damping layer 40 extends approximately 15mm beyond the boundary of the corresponding core air gap 21. After assembly, the fit gap between the oil-resistant flexible damping layers 40 and the exposed surfaces of the core is approximately 0.5mm. Four oil-resistant elastic supports 50 were installed between the lower core clamp 22 and the bottom plate of the oil tank. The oil-resistant elastic supports 50 are made of oil-resistant polyurethane elastomer, each with a height of 30mm and a diameter of 50mm, and are spaced apart along the main stress points of the lower core clamp 22. The oil flow heat exchange structure 70 includes widened oil channels, oil guiding components 72, a forced oil circulation unit, and an external heat dissipation unit. Specifically, the width of the original horizontal oil channels is increased from 8mm to 12mm, a 50% increase; four longitudinal oil guiding components 72 are installed between the iron core 20 and the oil tank 10; the rated flow rate of the low-noise oil pump is 10m³ / h; and the heat dissipation area of ​​the external finned radiator is increased by approximately 30% compared to the original structure. Before being injected into the oil tank 10, the natural ester insulating oil 60 undergoes vacuum dehydration and degassing treatment, with a moisture content of 38mg / kg and a breakdown voltage of 68kV. After oil injection, oil circulation is initiated, allowing the natural ester insulating oil 60 to fill the interior of the oil tank 10, the fitting gaps, and the space around the oil-resistant elastic support 50.

[0054] Example 2 uses lighter modification parameters. Its main differences from Example 1 are: the thickness of the oil-resistant flexible damping layer 40 is 5mm, and its coverage extends approximately 10mm beyond the boundary of the air gap 21 in the iron core; the number of oil-resistant elastic support members 50 is 6; the oil channel width is increased from 8mm to 10mm, an increase of 25%; the longitudinal oil guiding component 72 is not provided, and natural oil circulation is still used, with an external heat dissipation unit increasing the external heat dissipation area by approximately 50%. Before being injected into the oil tank 10, the moisture content of the natural ester insulating oil 60 is 45mg / kg, and the breakdown voltage is 62kV.

[0055] Example 3 employs a configuration with higher damping and stronger heat dissipation. Its main differences from Example 1 are: the thickness of the oil-resistant flexible damping layer 40 is 15mm, extending approximately 20mm beyond the boundary of the air gap 21 in the iron core; the number of oil-resistant elastic supports 50 is six, and their equivalent stiffness is matched according to the 100Hz and 200Hz vibration components; the oil channel width is increased from 8mm to 12mm; six longitudinal oil guiding components 72 are installed; the rated flow rate of the oil pump in the forced oil circulation unit is 12m³ / h; and the heat dissipation area of ​​the external heat dissipation unit is increased by approximately 40% compared to the original structure. Before being injected into the oil tank 10, the moisture content of the natural ester insulating oil 60 is 36mg / kg, and its breakdown voltage is 70kV.

[0056] To evaluate the effects of each component, Comparative Examples 1-10 were established. Comparative Example 1 was the basic prototype, without any vibration reduction or noise reduction modifications, still using the original mineral insulating oil, and without the oil-resistant flexible damping layer 40, oil-resistant elastic support 50, and oil flow heat exchange structure 70. Comparative Example 2 simply replaced the original mineral insulating oil with natural ester insulating oil 60, and without the oil-resistant flexible damping layer 40, oil-resistant elastic support 50, and oil flow heat exchange structure 70. Comparative Example 3 only used the same oil-resistant flexible damping layer 40 and oil-resistant elastic support 50 as Example 1, but still used mineral insulating oil, and did not adapt the oil flow heat exchange path. Comparative Example 4 only used the same oil flow heat exchange structure 70 as Example 1, but still used mineral insulating oil, and without the oil-resistant flexible damping layer 40 and oil-resistant elastic support 50. Comparative Example 5 replaced the mineral insulating oil with natural ester insulating oil 60 and included the same oil-resistant flexible damping layer 40 and oil-resistant elastic support 50 as in Example 1, but without the oil flow heat exchange structure 70. Comparative Example 6 replaced the mineral insulating oil with natural ester insulating oil 60 and used the same oil flow heat exchange structure 70 as in Example 1, but without the oil-resistant flexible damping layer 40 and oil-resistant elastic support 50. Comparative Example 7 replaced the mineral insulating oil with natural ester insulating oil 60 and included a graded damping structure and oil flow heat exchange structure 70, but the thickness of the oil-resistant flexible damping layer 40 was 2 mm, and its coverage was only approximately flush with the boundary of the air gap 21 in the iron core. Comparative Example 8 replaced the mineral insulating oil with natural ester insulating oil 60 and included a graded damping structure and oil flow heat exchange structure 70, but the thickness of the oil-resistant flexible damping layer 40 was 30 mm, and its coverage extended approximately 30 mm beyond the boundary of the air gap 21 in the iron core. Comparative Example 9 replaced the mineral insulating oil with natural ester insulating oil 60 and set up the same graded damping structure as Example 1. However, the heat dissipation compensation of the oil flow heat exchange structure 70 was insufficient. Specifically, the oil channel width was only increased from 8 mm to 9 mm, an increase of 12.5%. The oil guiding component 72 and the forced oil circulation unit were not set up. Only the heat dissipation area of ​​the external heat dissipation unit was increased by about 20%. Comparative Example 10 replaced the mineral insulating oil with natural ester insulating oil 60 and set up the same graded damping structure and forced oil circulation unit as Example 1. However, the oil channel width was increased from 8 mm to 16 mm, an increase of 100%.

[0057] Performance tests include vibration acceleration level, radiated noise sound pressure level, top oil temperature rise, winding hot spot temperature, and insulating oil acid value after operation. In the vibration acceleration level test, an acceleration sensor is placed at the center of the surface of the tank 10 to measure the vibration acceleration level at the 100Hz component. The vibration reduction value for other embodiments and the comparative example is calculated using the measurement result of Comparative Example 1 as a benchmark. In the radiated noise sound pressure level test, the A-weighted sound pressure level is measured at a distance of 1m from the surface of the tank 10. The noise reduction value is calculated using the measurement result of Comparative Example 1 as a benchmark. Noise testing can be performed according to the relevant methods specified in GB / T 1094.10. In the top oil temperature rise test, the reactor is operated under rated conditions until the oil temperature stabilizes, and the difference between the top oil temperature and the ambient temperature is measured. The winding hot spot temperature is obtained using a fiber optic temperature sensor or an equivalent hot spot temperature measurement method. In the insulating oil acid value test, the insulating oil acid value is sampled and tested after the reactor has been running continuously for 72 hours.

[0058]

[0059] Table 1 Combination Figure 5 As shown in Table 1, Examples 1-3 all achieved higher vibration and noise reduction values ​​compared to Comparative Example 1. Example 1 showed a vibration reduction of 7.5 dB and a noise reduction of 6.2 dB(A); Example 2 showed a vibration reduction of 6.2 dB and a noise reduction of 5.1 dB(A); and Example 3 showed a vibration reduction of 8.1 dB and a noise reduction of 6.8 dB(A). These results demonstrate that when the oil-resistant flexible damping layer 40, the natural ester insulating oil 60 in the bonding gap, and the oil-resistant elastic support 50 work together, the vibration and noise of the oil-immersed reactor can be effectively attenuated.

[0060] like Figure 6 As shown, the top layer oil temperature rise of Comparative Examples 1, 2, 5, 1, and 3 gradually increased with operating time and tended to stabilize after continuous operation. Comparative Example 1 used mineral insulating oil, resulting in a lower steady-state top layer oil temperature rise; Comparative Example 2 only replaced the mineral insulating oil with natural ester insulating oil 60, lacking an oil flow heat transfer path matched to the high-viscosity oil, resulting in a significantly higher steady-state temperature rise; Comparative Example 5, although equipped with a graded damping structure and having a good vibration reduction effect, did not adapt the oil flow heat transfer path, and the steady-state temperature rise was still higher than the control limit. Examples 1 and 3, using natural ester insulating oil 60 and a graded damping structure while configuring an oil flow heat transfer structure 70, were able to maintain the steady-state temperature rise below the control limit. Table 1 further lists the steady-state test results of Examples 1-3 and Comparative Examples 1-10.

[0061] As shown in Table 1, the top oil temperature rises in Examples 1-3 were 56.5K, 58.0K, and 55.0K, respectively. Compared to 54.0K in Comparative Example 1, the temperature rises in Examples 1-3 were slightly increased, but still within a controllable range. The winding hot spot temperatures in Examples 1-3 were 108℃, 111℃, and 106℃, respectively, all lower than the winding hot spot temperature control threshold of 120℃ set in this example. This indicates that even with the high viscosity of the natural ester insulating oil 60, the thermal reliability requirements of the oil-immersed reactor can still be met by configuring the oil flow heat exchange structure 70.

[0062] Comparative Example 2 only replaced the mineral insulating oil with natural ester insulating oil 60. Its vibration reduction was only 1.2 dB, and its noise reduction was only 1.0 dB(A), indicating that simply changing the oil is not sufficient to significantly reduce vibration and noise. Simultaneously, the top oil temperature rise in Comparative Example 2 reached 68.0 K, the winding hot spot temperature reached 128 °C, and the insulating oil acid value rose to 0.04 mg KOH / g after operation. These results demonstrate that, in the absence of a suitable oil flow heat transfer path, high-viscosity natural ester insulating oil 60 can significantly increase the temperature rise and may affect the stability of the insulating oil.

[0063] Comparative Example 3 only includes an oil-resistant flexible damping layer 40 and an oil-resistant elastic support 50, still using mineral insulating oil. Its vibration reduction value is 3.5 dB, and its noise reduction value is 2.8 dB(A), which is better than Comparative Example 1 but lower than Examples 1-3. This indicates that solid damping and bottom vibration isolation can attenuate some vibrations, but the low viscosity of mineral insulating oil limits its shear energy dissipation capacity in the bonding gap, making it difficult to fully utilize the local fluid damping effect.

[0064] Comparative Example 4 only features the oil flow heat exchange structure 70, still uses mineral insulating oil, and lacks the oil-resistant flexible damping layer 40 and oil-resistant elastic support 50. Its top oil temperature rise decreased to 52.5 K, and the winding hot spot temperature was 99 °C, but the vibration reduction was only 0.5 dB, and the noise reduction was only 0.4 dB(A). These results indicate that the oil flow heat exchange structure 70 is mainly used to improve temperature rise, and its attenuation effect on vibrations near the air gap and vibrations along the support path is limited.

[0065] Comparative Example 5 replaced the mineral insulating oil with natural ester insulating oil 60 and added an oil-resistant flexible damping layer 40 and an oil-resistant elastic support 50, but did not include the oil flow heat exchange structure 70. Its vibration reduction value was 7.3 dB and its noise reduction value was 6.0 dB(A), close to that of Example 1, indicating that the combination of natural ester insulating oil 60 and the graded damping structure can achieve good vibration and noise reduction effects. However, in Comparative Example 5, the top oil temperature rose to 70.5 K, the winding hot spot temperature reached 132 °C, and the insulating oil acid value rose to 0.05 mg KOH / g after operation, indicating that without adaptation of the oil flow heat exchange path, the reactor has a risk of overheating operation.

[0066] Comparative Example 6 replaced the mineral insulating oil with natural ester insulating oil 60 and configured an oil flow heat exchange structure 70, but omitted the oil-resistant flexible damping layer 40 and the oil-resistant elastic support 50. Its top oil temperature rise was 56.0 K, and the winding hot spot temperature was 107 °C. The temperature rise control was close to that of Example 1, but the vibration reduction was only 1.8 dB, and the noise reduction was only 1.5 dB(A). These results indicate that relying solely on the natural ester insulating oil 60 and the oil flow heat exchange structure 70 is insufficient to replace the damping structure adjacent to the core air gap and the bottom support vibration isolation structure.

[0067] In Comparative Example 7, the thickness of the oil-resistant flexible damping layer 40 is 2 mm, and its coverage is only basically flush with the boundary of the air gap 21 in the iron core. Its vibration reduction value is 4.5 dB, and its noise reduction value is 3.7 dB(A), lower than that of Example 1. This result indicates that the oil-resistant flexible damping layer 40 needs to have a suitable thickness and coverage to allow vibrations in the vicinity of the air gap 21 in the iron core to adequately enter the damping and energy dissipation region.

[0068] In Comparative Example 8, the thickness of the oil-resistant flexible damping layer 40 was 30 mm, extending approximately 30 mm beyond the boundary of the air gap 21 in the iron core. Its vibration reduction was 7.8 dB, and its noise reduction was 6.5 dB(A), showing limited improvement compared to Example 1. Simultaneously, the top layer oil temperature rose to 57.0 K, and the acid value of the insulating oil after operation was 0.03 mg KOH / g. These results indicate that when the oil-resistant flexible damping layer 40 is too thick, the increase in vibration and noise reduction benefits is not significant; instead, it increases installation difficulty and may affect the local oil flow arrangement. Therefore, the thickness of the oil-resistant flexible damping layer 40 should ideally be controlled within the range of 5 mm to 20 mm.

[0069] Comparative Example 9 uses the same graded damping structure as Example 1, but the oil flow heat transfer path is not adequately adapted. Its vibration reduction value is 7.4 dB, and its noise reduction value is 6.1 dB(A), showing a vibration and noise reduction effect close to Example 1. However, the top layer oil temperature rise reaches 64.0 K, and the winding hot spot temperature reaches 120 °C. This result indicates that when natural ester insulating oil 60 participates in fluid damping energy dissipation, if the oil passage cross-section, oil guiding component 72, and forced circulation capacity are insufficient, the problem of excessively high temperature rise will still occur.

[0070] In Comparative Example 10, the oil passage width was increased from 8 mm to 16 mm, an increase of 100%. The vibration reduction was 7.6 dB, the noise reduction was 6.3 dB(A), the top oil temperature rise was 58.5 K, and the winding hot spot temperature was 112 °C. Based on the temperature rise and vibration results, Comparative Example 10 meets the basic operating requirements. However, excessively widening the oil passage will occupy space for insulation and structural layout, potentially altering the oil flow distribution and increasing manufacturing or modification costs. Therefore, the increase in oil passage width should be controlled within the range of 20%-50%, taking into account the equipment structure.

[0071] like Figure 7As shown, after multiple thermal cycles, the kinematic viscosity of natural ester insulating oil 60 at 40℃ gradually decreased from approximately 34 mm² / s to approximately 29.5 mm² / s, without exhibiting a viscosity-increasing or deteriorating trend due to thermal cycling. This result indicates that after vacuum dehydration and degassing treatment, and with the temperature rise controlled by the oil flow heat exchange structure 70, the viscosity of natural ester insulating oil 60 remains within the range suitable for operation of oil-immersed reactors, maintaining the basic properties required for insulation, cooling, and fluid damping.

[0072] As can be seen from the above embodiments, comparative examples, and performance test results, this invention is not simply replacing mineral insulating oil with natural ester insulating oil 60, nor is it simply adding a solid damping structure or heat dissipation structure. This invention uses an oil-resistant flexible damping layer 40 and a bonding gap to allow natural ester insulating oil 60 to enter the confined gap near the core air gap 21, forming an oil film for shear energy dissipation; the oil-resistant elastic support member 50 weakens the vibration transmitted from the core 20 to the bottom plate of the oil tank via the core lower clamp 22; and the oil flow heat exchange structure 70 compensates for the adverse heat exchange effects caused by the high viscosity of natural ester insulating oil 60. These technical features are mutually complementary, enabling simultaneous improvement in vibration noise levels and temperature rise control without altering the main electromagnetic structure of the reactor.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for vibration reduction and noise reduction of an oil-immersed reactor, applied to an oil-immersed reactor with a segmented air-gap core; characterized in that, The method includes: An oil-resistant flexible damping layer is provided on the exposed surfaces of the iron core on both sides corresponding to at least one iron core air gap, and a bonding gap is formed between the oil-resistant flexible damping layer and the corresponding exposed surface of the iron core, which can be immersed in natural ester insulating oil. An oil-resistant elastic support is installed between the lower clamp of the iron core and the bottom plate of the oil tank. The oil-resistant flexible damping layer and the oil-resistant elastic support are located in the vibratory source area near the air gap of the iron core and on the iron core support transmission path, respectively. Inject pre-treated natural ester insulating oil into the oil tank. The natural ester insulating oil fills the inside of the oil tank, the bonding gaps, and the space around the oil-resistant elastic support. Configure an oil flow heat exchange path that matches the viscosity of the natural ester insulating oil. The natural ester insulating oil flows along the oil flow heat exchange path through the heat-generating area inside the oil tank and exchanges heat with the heat dissipation area of ​​the oil tank or an external heat dissipation unit.

2. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 1, characterized in that, The oil-resistant flexible damping layer is disposed on the exposed side of the adjacent core segment forming the core air gap, and avoids the main magnetic flux working interval of the core air gap.

3. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 1, characterized in that, The oil-resistant flexible damping layer is made of rubber elastomer or polyurethane elastomer that is resistant to natural ester insulating oil; The thickness of the oil-resistant flexible damping layer is 5mm-20mm; The oil-resistant flexible damping layer covers the exposed surface of the iron core by 10mm-30mm beyond the corresponding air gap boundary of the iron core.

4. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 1, characterized in that, The gap size of the bonding gap is less than or equal to 1mm, and the natural ester insulating oil forms an oil film shear damping zone between the exposed surface of the iron core and the oil-resistant flexible damping layer.

5. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 1, characterized in that, The number, arrangement, and equivalent stiffness of the oil-resistant elastic support components are determined based on the core mass and the 100Hz or 200Hz vibration component during core operation, so that the vibration transmitted from the core to the bottom plate of the oil tank through the lower core clamp is attenuated.

6. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 1, characterized in that, The kinematic viscosity of natural ester insulating oil at 40℃ is 30mm² / s-35mm² / s, and its ignition point is not lower than 300℃. Natural ester insulating oil undergoes vacuum dehydration and degassing treatment before being injected into the oil tank. The moisture content after treatment is less than or equal to 50 mg / kg, and the breakdown voltage is greater than or equal to 60 kV.

7. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 1, characterized in that, The oil flow heat exchange path is formed by increasing the cross-section of the oil passage, setting up oil guiding components, adopting a forced oil circulation unit, or setting up an external heat dissipation unit.

8. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 7, characterized in that, Increasing the flow cross-section of the oil passage includes: For modified oil-immersed reactors, the width of the oil passage before modification will be increased by 20%-50%; For newly manufactured oil-immersed reactors, the oil channel width is increased by 20%-50% compared to the oil channel width suitable for mineral insulating oil; Alternatively, a longitudinal oil passage may be added at least at one point between the iron core and the winding, between the iron core and the oil tank, or between the winding and the oil tank.

9. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 7, characterized in that, The oil guiding component is located between the iron core and the oil tank. The oil guiding component is used to guide the natural ester insulating oil to flow through the hot spot area of ​​the winding, the area near the air gap of the iron core, or the hot spot area at the top of the oil tank.

10. The method for vibration reduction and noise reduction of an oil-immersed reactor according to claim 7, characterized in that, The forced oil circulation unit includes a low-noise oil pump, the flow rate of which is adjusted according to at least one of the top oil temperature rise, winding hot spot temperature, or tank wall temperature. An external heat dissipation unit is used to increase the external heat dissipation area of ​​the fuel tank.

11. The method for vibration reduction and noise reduction of an oil-immersed reactor according to any one of claims 1-10, characterized in that, Also includes: Collect at least one of the following: oil tank wall vibration signal, iron core vibration signal, top oil temperature signal, or winding hot spot temperature signal; When the collected signal exceeds the corresponding preset threshold, the oil flow rate is adjusted if the oil flow heat exchange path includes an adjustable oil flow drive component, or an alarm signal is output.

12. An oil-immersed reactor for implementing the vibration reduction and noise reduction method for an oil-immersed reactor as described in any one of claims 1-11, characterized in that, include: tank; The iron core is installed inside the oil tank and has segmented air gaps. A winding, fitted over at least a portion of the iron core; An oil-resistant flexible damping layer is disposed on the exposed surfaces of the iron core on both sides corresponding to at least one iron core air gap, and a fitting gap is formed between the oil-resistant flexible damping layer and the corresponding exposed iron core surface. An oil-resistant elastic support is installed between the lower clamp of the iron core and the bottom plate of the oil tank; Natural ester insulating oil is used to fill the interior of the oil tank, the gaps between components, and the space around the oil-resistant elastic support; and The oil flow heat exchange structure is matched with the viscosity of the natural ester insulating oil. The oil flow heat exchange structure is used to form an oil flow heat exchange path for the natural ester insulating oil to flow through the heat-generating area inside the oil tank and exchange heat with the heat dissipation area of ​​the oil tank or an external heat dissipation unit. The bonding gap is used to form a shear flow energy dissipation zone for natural ester insulating oil when vibration occurs at the air gap of the iron core. The oil-resistant flexible damping layer and the oil-resistant elastic support are used to attenuate the vibration in the area adjacent to the air gap of the iron core and the vibration transmitted from the iron core to the bottom plate of the oil tank, respectively.

13. The oil-immersed reactor according to claim 12, characterized in that, The oil flow heat exchange structure includes at least one of the following: widened oil passage, oil guiding component, forced oil circulation unit, or external heat dissipation unit.

14. The oil-immersed reactor according to claim 13, characterized in that, Oil-immersed reactors also include vibration sensors, temperature sensors, signal acquisition modules, controllers, cooling flow regulation modules, and alarm modules; Vibration sensors are installed on the outside of the tank wall or at the iron core clamp. The temperature sensor is located in the upper oil layer of the oil tank or at the hot spot of the winding. The signal acquisition module has a first signal input terminal, a second signal input terminal, and a signal acquisition output terminal. The first signal input terminal is connected to the vibration sensor, the second signal input terminal is connected to the temperature sensor, and the signal acquisition output terminal is connected to the acquisition input terminal of the controller. The controller has a flow control output terminal and an alarm output terminal. The flow control output terminal is connected to the control input terminal of the cooling flow regulation module, and the alarm output terminal is connected to the alarm input terminal of the alarm module. The cooling flow rate regulation module is connected to the oil circulation pipeline of the oil flow heat exchange structure, and the alarm module is set in the local control box of the oil-immersed reactor, or the alarm module is connected to the background monitoring system.

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