Oil-immersed composite vacuum on-load tap changer

Abstract

The utility model provides a kind of oil-immersed composite vacuum load tap changer, including oil chamber and the switching core being rotatably installed in oil chamber, switching core includes the insulating main shaft being rotatably arranged in oil chamber, and at least one switching mechanism being fixed on insulating main shaft;Each switching mechanism includes upper mounting plate, lower mounting plate, vacuum arc extinguishing system, movable contact system, transition resistance and roller;Upper mounting plate and lower mounting plate are sequentially fixed on insulating main shaft from top to bottom;Two ends of vacuum arc extinguishing system are respectively installed on upper mounting plate and lower mounting plate, and it includes V1 vacuum arc extinguishing system and V2 vacuum arc extinguishing system;Movable contact system is installed between V1 vacuum arc extinguishing system and V2 vacuum arc extinguishing system;Transition resistance is installed on lower mounting plate;The number of roller is multiple and is rotatably installed in the inside of oil chamber respectively.The utility model structure is compact, small in size, low in height, low in cost, substantially reduces installation process, saves assembly time, improves assembly efficiency.

Description

Technical Field

[0001] This utility model relates to the field of on-load tap changer technology, and in particular to an oil-immersed composite vacuum on-load tap changer. Background Technology

[0002] like Figure 1 and Figure 2 This diagram illustrates the structure of an existing oil-immersed composite vacuum on-load tap changer and its switching core. It mainly includes an oil chamber, a switching core installed within the oil chamber, and an energy storage system for driving the switching core to perform switching actions. The switching core primarily consists of a non-rotatable insulated main shaft, a cam disc mounted on the insulated main shaft and equipped with multiple cams, three vertical supports mounted on the outside of the main shaft and capable of rotating around it, and a moving contact system and an arc-extinguishing system installed between the supports. During installation, the cam disc and supports must be installed sequentially first, and then the moving contact system and arc-extinguishing system are installed on the supports using the relevant connecting parts. This structure has the following disadvantages:

[0003] First, the cam plate is set between the support and the insulating main shaft. The arc extinguishing system of the support needs to cooperate with the cam on the cam plate. This requires the support to be a certain distance away from the insulating main shaft (outward expansion) to leave enough space for the cam plate installation and the cam and the arc extinguishing system to cooperate. This results in an increase in the overall diameter and volume of the switching core, which indirectly increases the volume of the oil chamber, vacuum on-load tap changer and transformer, and also increases material and manufacturing costs.

[0004] Secondly, maintenance is troublesome. When the cam is worn and needs to be repaired, the bracket, its moving contact system, vacuum arc extinguishing system, and insulated spindle must be removed before the cam disc can be replaced. After replacement, the bracket, its moving contact system, and vacuum arc extinguishing system must be reinstalled, making the replacement process complicated.

[0005] Finally, the moving contact system has a complex structure, is troublesome to install and maintain, and also increases material and manufacturing costs.

[0006] In summary, the aforementioned defects of existing oil-immersed composite vacuum on-load tap changers result in a large switch structure, high height, and high manufacturing costs, which also increase the manufacturing cost of transformers. This is particularly true for transformers below 40.5kV, where the low voltage, small insulation distance, and small transformer body necessitate a larger transformer body and increased height to meet the requirements of existing oil-immersed composite vacuum on-load tap changers, significantly increasing manufacturing costs. Meanwhile, this switch can replace similar oil-immersed arc-extinguishing switches on the market. Utility Model Content

[0007] To address the aforementioned problems, the purpose of this invention is to provide an oil-immersed composite vacuum on-load tap changer that is small in size, low in height, and low in cost.

[0008] The objective of this utility model is achieved through the following technical solution:

[0009] An oil-immersed composite vacuum on-load tap changer includes an oil chamber and a switching core rotatably mounted within the oil chamber. The switching core includes an insulating main shaft rotatably mounted within the oil chamber and at least one switching mechanism fixed to the insulating main shaft. Each switching mechanism includes an upper mounting plate, a lower mounting plate, a vacuum arc-extinguishing system, a moving contact system, a transition resistor, and rollers. The upper and lower mounting plates are sequentially fixed to the insulating main shaft from top to bottom. The two ends of the vacuum arc-extinguishing system are respectively mounted on the upper and lower mounting plates, and it includes a V1 vacuum arc-extinguishing system and a V2 vacuum arc-extinguishing system. The moving contact system is installed between the V1 and V2 vacuum arc-extinguishing systems. The transition resistor is mounted on the lower mounting plate. Multiple rollers are rotatably mounted inside the oil chamber. The vacuum arc-extinguishing system can cooperate with the rollers as the insulating main shaft rotates, enabling the vacuum arc-extinguishing system to open and close.

[0010] Furthermore, the moving contact system includes a neutral point leading-out moving contact, a K1 current-carrying switching contact, and a K2 transition switching contact; the neutral point leading-out moving contact is mounted on the upper mounting plate; the K1 current-carrying switching contact and the K2 transition switching contact are both fixed on the lower mounting plate, wherein the K2 transition switching contact is located between the V2 vacuum arc-extinguishing system and the K1 current-carrying switching contact; the K1 current-carrying switching contact, the V1 vacuum arc-extinguishing system, and the neutral point leading-out moving contact are connected in series; the K2 transition switching contact, the transition resistor, the V2 vacuum arc-extinguishing system, and the neutral point leading-out moving contact are connected in series.

[0011] Furthermore, at least one stationary contact system corresponding to each switching mechanism is provided on the oil chamber; each stationary contact system includes an outgoing stationary contact mechanism and an input stationary contact mechanism; the outgoing stationary contact mechanism includes a conductive ring fixed to the inner wall of the oil chamber and an outgoing stationary contact fixed to the outer wall of the oil chamber and connected to the conductive ring; the conductive ring and the neutral point outgoing moving contact on the corresponding switching mechanism are always in contact; the input stationary contact mechanism includes multiple input stationary contact groups arranged in a ring on the oil chamber, each input stationary contact group includes a conductive sheet fixed to the inner wall of the oil chamber and an input stationary contact fixed to the outer wall of the oil chamber and connected to the conductive sheet; the conductive sheet is in contact with the K1 current-carrying changeover contact and the K2 transition changeover contact respectively, and both the K1 current-carrying changeover contact and the K2 transition changeover contact can move to another position and contact another conductive sheet as the insulating spindle rotates.

[0012] Furthermore, the neutral point lead-out moving contact, K1 current-carrying conversion contact, and K2 transition conversion contact are identical and each consists of a support member, a clamping spring, and at least one moving contact group. The support member is fixed to the corresponding upper and lower mounting plates, and mounting grooves are provided on the upper and lower sides of the support member. A vertical through hole is provided in the support member near the insulating spindle. Each moving contact group includes two moving contacts located in the upper and lower mounting grooves of the support member. The middle part of each moving contact is rotatably mounted in the mounting groove through a positioning pin. One end of the moving contact points to the oil chamber, and the other end points to the insulating spindle and is located above the vertical through hole. The clamping spring is set in the vertical through hole, and its two ends extend out of the vertical through hole and contact the two moving contacts respectively, so that the ends of the two moving contact groups away from the insulating spindle are brought closer to each other.

[0013] Furthermore, the V1 vacuum arc extinguishing system and the V2 vacuum arc extinguishing system are identical in composition, both consisting of a vacuum bulb, a guide member, a pull rod, a limiting plate, a spring, a support member, and a lever. The lower end of the vacuum bulb is mounted on the lower mounting plate. The guide member is fixed to the top of the upper mounting plate and located directly above the vacuum bulb. The lower end of the pull rod is connected to the upper end of the vacuum bulb and can drive the vacuum bulb to open and close. The upper end of the pull rod moves through a pre-set mounting hole on the upper mounting plate and slides into a pre-set guide hole in the guide member. The limiting plate is fixed on the pull rod and located between the vacuum bulb and the guide member. The spring is sleeved on the outside of the pull rod and located in the mounting hole of the upper mounting plate. Its upper end contacts the bottom of the guide member, and its lower end contacts the top of the limiting plate. The support member is fixed to the bottom of the upper mounting plate and located between the pull rod and the roller. The lever is rotatably mounted on the support member. One end of the lever is sleeved on the pull rod and contacts the bottom of the limiting plate, and the other end is located below the roller and cooperates with the roller.

[0014] Furthermore, a cam is fixed at one end of the lever that engages with the roller. When the cam moves to contact the roller, it is pressed down by the roller, causing the lever to rotate around the shaft. This causes the other end of the lever to pry the limiting plate and the pull rod upward, compressing the spring and breaking the vacuum bubble.

[0015] The beneficial effects of this utility model are as follows:

[0016] This utility model features a compact structure, small size, low height, low cost, and convenient maintenance, significantly reducing installation procedures, saving assembly time, and improving assembly efficiency. It adopts a layered switching mechanism design, with three switching mechanisms arranged longitudinally along the insulating main shaft, eliminating the need for traditional supports and related supporting mechanisms. Simultaneously, it optimizes the structure and drive method of the arc-extinguishing system, reducing material costs and making its operation more efficient. The integrated layout of the vacuum arc-extinguishing system and contact system reduces traditional mechanical transmission components, effectively lowering the overall height of the equipment. Through these features, significant reductions in size, height, and cost are achieved while ensuring electrical performance, making it particularly suitable for space-constrained installation scenarios such as urban power grid upgrades and underground substations. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the structure of an existing oil-immersed composite vacuum on-load tap changer.

[0019] Figure 2 This is a schematic diagram of the switching core in an existing oil-immersed composite vacuum on-load tap changer.

[0020] Figure 3 This is a schematic diagram of the structure of the oil-immersed composite vacuum on-load tap changer described in this utility model.

[0021] Figure 4 This is a schematic diagram of the switching core in the oil-immersed composite vacuum on-load tap changer of this utility model.

[0022] Figure 5 for Figure 3 A cross-sectional view of the K1 current-carrying switching contact and the neutral point lead-out moving contact in the switching mechanism at the bottom of the switching core.

[0023] Figure 6 for Figure 3 A cross-sectional view of the V1 vacuum arc extinguishing system in the switching mechanism at the bottom of the switching core.

[0024] Figure 7 for Figure 3 A schematic diagram showing the state when the lower end of the switching core is assembled into the oil chamber.

[0025] The diagram shows: 1-Oil chamber, 2-Head cover gear box, 3-Energy storage system, 4-Switching core, 5-Oil extraction pipe, 6-Bearing seat, 7-Insulated spindle, 8-Upper mounting plate, 9-Neutral point lead-out moving contact, 10-Connecting wire one, 11-Transition resistor, 12-V2 vacuum arc extinguishing system, 13-Connecting wire two, 14-Lower mounting plate, 15-Counterweight, 16-K2 transition changeover contact, 17-K1 current-carrying changeover contact, 18-Connecting wire three, 19-V1 vacuum arc extinguishing system, 20-Connecting wire four, 21-Fasting bolt, 22-Metal ring, 23-Pressure bolt, 24-Clamping spring. 25-Protective shell, 26-Moving contact, 27-Positioning pin one, 28-Conductive ring, 29-Bolt, 30-Nut, 31-Lead-out stationary contact, 32-Positioning pin two, 33-Support component, 34-Input stationary contact, 35-Mounting nut, 36-Support ring, 37-Bearing, 38-Mounting bolt, 39-Vacuum bubble, 40-Fastening nut, 41-Pull rod, 42-Spring, 43-Guide component, 44-Fastening screw, 45-Support component, 46-Roller, 47-Shaft one, 48-Lever, 49-Shaft two, 50-Cylinder, 51-Limiting plate, 52-Cam, 53-Conductive sheet. Detailed Implementation

[0026] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. The described embodiments are merely some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example 1

[0029] like Figures 3 to 7 As shown, this embodiment provides an oil-immersed composite vacuum on-load tap changer, including an oil chamber 1 and a switching core 4.

[0030] The oil chamber 1 adopts a cylindrical structure similar to that used in conventional oil-immersed composite vacuum on-load tap changers, providing a sealed container for housing the switching core 4 and providing an installation position for mounting the switch on the transformer body. A cylinder 50 for mounting the switching core 4 is located at the bottom of the oil chamber 1. Similar to conventional oil-immersed composite vacuum on-load tap changers, the oil chamber 1 also houses a head cover gearbox 2 for transmission and an energy storage system 3. Both the head cover gearbox 2 and the energy storage system 3 are conventional structures for conventional oil-immersed composite vacuum on-load tap changers. The head cover gearbox 2 (essentially a gearbox) transmits external torque to the energy storage system 3 for energy storage. The energy storage system 3 provides power for the switching of the entire switching core 4 by releasing energy. The energy storage system 3 is connected to the oil chamber 1 and fixed to the top of the oil chamber 1.

[0031] Three stationary contact systems, each corresponding to a switching mechanism, are arranged from top to bottom on the oil chamber 1; each stationary contact system includes an outgoing stationary contact mechanism and an input stationary contact mechanism.

[0032] The lead-out stationary contact mechanism includes a conductive ring 28 and a lead-out stationary contact 31; the conductive ring 28 is fixedly fixed on the inner wall of the oil chamber 1, and the lead-out stationary contact 31 is fixed on the outer wall of the oil chamber 1 and is in communication with the conductive ring 28. The conductive ring 28 and the lead-out stationary contact 31 are fastened and connected by bolts 29 and nuts 30; the conductive ring 28 and the neutral point lead-out moving contact 9 on the corresponding switching mechanism are always in contact.

[0033] The input stationary contact mechanism includes multiple input stationary contact groups arranged in a ring on the oil chamber 1. Each input stationary contact group includes a conductive sheet 53 fixed on the inner wall of the oil chamber 1 and an input stationary contact 34 fixed on the outer wall of the oil chamber 1 and connected to the conductive sheet 53. The conductive sheet 53 is in contact with the K1 current-carrying changeover contact 17 and the K2 transition changeover contact 16 respectively. The K1 current-carrying changeover contact 17 and the K2 transition changeover contact 16 can move to another position and contact another conductive sheet 53 as the insulating main shaft 7 rotates. The stationary input contact 34 is fixed on the oil chamber 1 by a mounting nut 35. The input contact 34 is connected to the transformer coil tap and is responsible for the current input.

[0034] The switching core 4 is rotatably mounted inside the oil chamber 1 and connected to the energy storage system 3. The switching core includes an insulating main shaft 7 rotatably mounted inside the oil chamber 1, and three switching mechanisms fixed sequentially from top to bottom on the insulating main shaft. The three switching mechanisms correspond one-to-one with the three phases A, B, and C.

[0035] The insulating spindle 7 is the supporting component of the entire switching core 4 and is also responsible for the torque transmission of the entire switching core 4. The insulating spindle 7 is coaxially mounted outside the oil extraction pipe 5. The upper end of the insulating spindle 7 is equipped with a bearing seat 6 that is sleeved outside the oil extraction pipe 5. The bearing seat 6 is connected to the energy storage system 3 and transmits the torque of the energy storage system 3 to the insulating spindle 7. The lower end of the insulating spindle 7 is rotatably mounted outside the cylinder 50.

[0036] Each switching mechanism includes an upper mounting plate 8, a lower mounting plate 14, a vacuum arc extinguishing system, a moving contact system, a transition resistor 11, and a roller 46.

[0037] The upper mounting plate 8 and the lower mounting plate 14 are fixed to the insulating spindle 7 from top to bottom.

[0038] The upper mounting plate 8 is made of metal and is fixed to the outer wall of the insulating spindle 7 by fastening bolts 21 and metal ring 22 (the metal ring 22 is sleeved inside the insulating spindle 7, and multiple fastening bolts 21 pass through the upper mounting plate 8 and the insulating spindle 7 in sequence and are screwed into the pre-set screw holes on the metal ring 22, thereby fixing the upper mounting plate 8 to the outer wall of the insulating spindle 7).

[0039] The lower mounting plate 14 is made of insulating material and is fixed to the outer wall of the insulating spindle 7 by the support ring 36 via additional fastening bolts 21 (the support ring 36 is sleeved inside the insulating spindle 7, and multiple fastening bolts 21 pass through the lower mounting plate 14 and the insulating spindle 7 in sequence and are screwed into the pre-set screw holes on the support ring 36, thereby fixing the lower mounting plate 14 to the outer wall of the insulating spindle 7).

[0040] The rollers 46 are multiple and are rotatably mounted on the inner side of the oil chamber 1 (on the conductive ring 28) via shaft 47. Shaft 47 is vertically fixed on the inner wall of the conductive ring 28. The rollers 46 are coaxially mounted on shaft 47 and can rotate axially on shaft 47. The diameter of the rollers 46 is smaller than the distance between the upper and lower surfaces of the conductive ring 28, so as to facilitate the smooth passage between the two moving contacts 26 of the driven contact group.

[0041] The transition resistor 11 is mounted on the lower mounting plate 14.

[0042] The two ends of the vacuum arc extinguishing system are respectively installed on the upper mounting plate 8 and the lower mounting plate 14, and the vacuum arc extinguishing system includes V1 vacuum arc extinguishing system 19 and V2 vacuum arc extinguishing system 12.

[0043] The V1 vacuum arc extinguishing system 12 and the V2 vacuum arc extinguishing system 19 are identical and both consist of a vacuum bubble 39, a guide 43, a pull rod 41, a limiting plate 51, a spring 42, a support 45, and a lever 48.

[0044] The lower end of the vacuum bulb 39 is mounted on the lower mounting plate. It is a conventional electrical component. Its lower part is fixed to the lower mounting plate 14 by mounting bolts 38. The vacuum bulb 39 is connected in series in the current transition circuit system and the current carrying circuit system respectively (the vacuum bulb 39 of the V1 vacuum arc extinguishing system 19 is connected in series in the current carrying circuit system, and the vacuum bulb 39 of the V2 vacuum arc extinguishing system 12 is connected in series in the current transition circuit system). It plays the role of opening and closing the current, ensuring that the arc is extinguished in the vacuum bulb when the current is interrupted.

[0045] The guide member 43 is fixed to the top of the upper mounting plate 8 and located directly above the vacuum bubble 39. The middle part of the guide member 43 protrudes upward and has a polygonal guide hole on the protrusion to provide guidance for the pull rod 41 and prevent the pull rod 41 from rotating during movement.

[0046] The lower end of the pull rod 41 is connected to the upper end (movable contact) of the vacuum bulb 39 and can drive the vacuum bulb 39 to perform opening and closing actions. The upper end of the pull rod 41 moves through the preset mounting hole on the upper mounting plate 8 and then slides into the guide hole of the guide member 43. The upper end of the pull rod 41 cooperates with the guide hole of the guide member 43 and can only move up and down, but cannot rotate.

[0047] The limiting plate 51 is fixed on the pull rod 41 and located between the vacuum bubble 39 and the guide member 43, and it is located below the upper mounting plate 8.

[0048] The spring 42 is sleeved outside the pull rod 41 and located in the mounting hole of the upper mounting plate 8. The upper end of the spring 42 extends above the upper mounting plate 8 and contacts the bottom of the guide member 43. The lower end of the spring 42 extends below the upper mounting plate 8 and contacts the top of the limiting plate 51. The spring 42 provides a closing force to the vacuum bubble 39, ensuring reliable contact between the contacts (moving contacts and stationary contacts) inside the vacuum bubble 39.

[0049] The support 45 is fixed to the bottom of the upper mounting plate 8 by fastening screws 44 and is located between the pull rod 41 and the roller 46.

[0050] The middle part of the lever 48 is rotatably mounted on the support via a second shaft 49 (the second shaft 49 is perpendicular to the first shaft 47 and is used to mount the lever 48 on the support 45, while also providing a fulcrum for the rotation of the lever 48). One end of the lever 48 is sleeved on the pull rod 41 and contacts the bottom of the limiting plate 51 (this end of the lever 48 is U-shaped, and the lever 48 is sleeved on the outside of the pull rod 41 through the U-shaped groove), and the other end is located below the roller 56 and cooperates with the roller 46. A cam 52 is fixed at one end of lever 41 that engages with roller 46. Roller 46 is located on the movement trajectory of cam 52. The top two sides of cam 52 are inclined surfaces. When cam 52 rotates with lever 48 and moves to contact roller 46 (the inclined surfaces of cam 52 contact roller 46 first), its top is pressed down by roller 46 and moves downward, thereby driving lever 48 to rotate around shaft 49. This causes the other end of lever 48 (tilted upward) to pry the limiting plate 51 and pull rod 41 upward, compressing spring 42 and breaking vacuum bubble 39. During switching, switching core 4 rotates, and cam 52 engages with roller 46, so that when the circuit is interrupted, the arc is extinguished in vacuum bubble 39. By integrating cam 52 for opening and closing vacuum bubble 39 with lever 48, only one cam 52 is needed to meet the usage requirements, reducing the number of cams 52 and lowering the processing difficulty and cycle time.

[0051] The moving contact system is installed between the V1 vacuum arc extinguishing system 19 and the V2 vacuum arc extinguishing system 12, and includes a neutral point lead-out moving contact 9, a K1 current-carrying changeover contact 17 and a K2 transition changeover contact 16.

[0052] The neutral point lead-out moving contact 9 is mounted on the upper mounting plate 8 and is responsible for leading out the transformer coil current.

[0053] The K1 current-carrying changeover contact 17 is fixed on the lower mounting plate 14 and located directly below the neutral point lead-out moving contact 9. The K1 current-carrying changeover contact 17 is used to carry the load current of the entire switch.

[0054] The K2 transition contact 16 is also fixed on the lower mounting plate 14, and the K2 transition contact 16 is located between the V2 vacuum arc extinguishing system 12 and the K1 current-carrying contact 17. The K2 transition contact 16 is used to preselect the transformer coil and carry the instantaneous current when switching.

[0055] The K1 current-carrying changeover contact 17, the V1 vacuum arc-extinguishing system 19, and the neutral point lead-out moving contact 9 are connected in series to form a load current loop system. The K1 current-carrying changeover contact 17 and the V1 vacuum arc-extinguishing system 19 are electrically connected via connecting wire three 18. Specifically, one end of connecting wire three 18 is electrically connected to the lower part of the vacuum bulb 39 in the V1 vacuum arc-extinguishing system 19, and the other end is fixed to the moving contact 26 of the K1 current-carrying changeover contact 17 by a clamping bolt 23. The V1 vacuum arc-extinguishing system 19 and the neutral point lead-out moving contact 9 are electrically connected via connecting wire four 20. Specifically, one end of connecting wire four 20 is clamped to the upper part of the vacuum bulb 39 (on the pull rod 41) by a fastening nut 40, and the other end of connecting wire four 20 is fixed to the moving contact 26 of the neutral point lead-out moving contact 9 by other clamping bolts 23.

[0056] The K2 transition contact 16, transition resistor 11, V2 vacuum arc extinguishing system 12, and neutral point lead-out moving contact 9 are connected in series to form a current transition circuit system. The lower part of the vacuum bulb 39 of the V2 vacuum arc extinguishing system 12 is electrically connected to one end of the transition resistor 11 through connecting wire 2 13. The V2 vacuum arc extinguishing system 12 and the neutral point lead-out moving contact 9 are electrically connected through connecting wire 10. Specifically, one end of connecting wire 10 is pressed onto the upper part of the vacuum bulb 39 of the V2 vacuum arc extinguishing system (on the pull rod 41) by other fastening nuts 40, and the other end of connecting wire 10 is fixed to the moving contact 26 of the neutral point lead-out moving contact 9 by other clamping bolts 23.

[0057] The neutral point lead-out moving contact 9, K1 current-carrying conversion contact 17 and K2 transition conversion contact 16 have the same structure and are all composed of a support member 33, a clamping spring 24 and at least one moving contact group.

[0058] The support member 33 is fixed on the corresponding upper mounting plate 8 and lower mounting plate 14 respectively (the support member 33 of the neutral point lead-out moving contact 9 is fixed on the upper mounting plate 8, and the support member 33 of the K1 current-carrying conversion contact 17 and the K2 transition conversion contact 16 is fixed on the lower mounting plate 14). Mounting grooves are provided on the upper and lower sides of the support member 33 respectively, and a vertical through hole is provided in the support member 33 near the insulating spindle 7.

[0059] Each moving contact group includes two moving contacts 26 located in the upper and lower mounting slots of the support 33, respectively. The middle part of each moving contact 26 is rotatably mounted in the mounting slot via a positioning pin 27. The moving contact 26 is responsible for switching the electrical connection between the core 4 and the input stationary contact 34. One end of the moving contact 26 points towards the oil chamber 1 and maintains contact with the conductive sheet 53 on the inner wall of the oil chamber 1. The other end of the moving contact 26 points towards the insulating spindle 7 and is located above the vertical through hole. In the K1 current-carrying changeover contact 17 and the K2 transition changeover contact 16, the two moving contacts 26 of the moving contact group are located on the upper and lower sides of the conductive sheet 53, respectively, and both maintain contact with the upper and lower sides of the conductive sheet 53. (Clamped on the upper and lower sides of the conductive sheet 53 under the action of the clamping spring 24), the moving contact groups of both can move to another position and contact the other conductive sheet 53 as the insulating spindle 7 rotates; in the neutral point lead-out moving contact 9, the two moving contacts 26 of its moving contact group are respectively located on the upper and lower sides of the conductive ring 28 and always keep in contact with the upper and lower sides of the conductive ring 28 (clamped on the upper and lower sides of the conductive ring 28). At the same time, in the neutral point lead-out moving contact 9, the support member 33, the conductive ring 28 and the two moving contacts 26 form a gap. As the moving contact group rotates, the roller 46 is located on the movement trajectory of the gap and can pass through it smoothly.

[0060] The clamping spring 24 is installed in the vertical through hole, with its two ends extending out of the vertical through hole and contacting the two moving contacts 26 respectively. This causes the end of the moving contact group away from the insulating spindle 7 to move closer to the conductive sheet 53, clamping the conductive sheet 53 and providing clamping force to ensure reliable contact.

[0061] Each moving contact group has two moving contacts 26 sharing a clamping spring 24, which ensures that the pressure, conductivity, and wear of the two moving contacts 26 are balanced, thus extending the service life of the contacts.

[0062] In addition, the neutral point leading-out moving contact 9 and the K1 current-carrying changeover contact 17 have two moving contact groups, which are arranged side by side and their support members 33 are connected as one unit, while the K2 transition changeover contact 16 has only one moving contact group.

[0063] The switching steps for switching core 4 in this oil-immersed composite vacuum on-load tap changer are as follows:

[0064] S1. The motor drives the head cover gear box 2 to rotate and drive the energy storage system 3 to store energy. During the opening and closing of the switch, the energy storage spring 3 releases the stored energy and drives the insulated main shaft 7 to rotate.

[0065] During the rotation of the S2. Insulating spindle 7, one end of the lever 48 with cam 52 of the V2 vacuum arc extinguishing system first contacts the roller 46 on the inner wall of the conductive ring 28. As the rotation proceeds, the roller 46 moves upward along the inclined surface of the cam 52 to the top of the cam 52, causing the top of the cam 52 to be pressed down by the roller 46 and move downward, thereby driving the lever 48 to rotate around the shaft 49. This causes the other end of the lever 48 (tilted upward) to pry the limiting plate 51 and the pull rod 41 upward, compressing the spring 42 and causing the vacuum bulb 39 to break, thus disconnecting the current transition circuit system (the load current circuit system remains conductive to ensure that the switching process is uninterrupted). When the circuit breaks the current, the arc is extinguished in the vacuum bulb.

[0066] In the S3.V2 vacuum arc extinguishing system, after the vacuum bulb 39 is disconnected and the arc is extinguished, the K2 transition contact 16 disengages from the conductive sheet 53 that was initially in contact (the one that was first in contact) and moves toward another conductive sheet 53.

[0067] S4. The insulating spindle 7 continues to rotate. After the K2 transition contact 16 contacts another conductive plate 53, the end of the lever 48 with cam 52 in the V2 vacuum arc extinguishing system disengages from the roller 46. The spring 42 releases energy and extends, pushing the limiting plate 51 and the pull rod 41 downward. At the same time, the end of the lever 48 that contacts the limiting plate 51 also moves downward under the push of the limiting plate 51, causing the lever 48 to rotate. This causes the end of the lever 48 with cam 52 to move downward (to cooperate with the next roller 46). The pull rod 41 moves downward, causing the vacuum bubble 39 to close. Both the current transition circuit system and the load current circuit system are in the connected state. The K2 transition contact 16 and the K1 current-carrying contact 17 are respectively connected across two adjacent conductive plates 53, forming a short circuit. However, due to the presence of the transition resistance 11 in the current transition circuit system, the current in the circuit remains stable.

[0068] S5. The insulating spindle 7 rotates continuously again, causing one end of the lever 48 with cam 52 of the V1 vacuum arc extinguishing system to first contact the roller 46 on the inner wall of the conductive ring 28. As the rotation proceeds, the roller 46 moves upward along the inclined surface of cam 52 to the top of cam 52, causing the top of cam 52 to be pressed down by the roller 46 and move downward, thereby driving the lever 48 to rotate around the shaft 49, causing the other end of the lever 48 (tilted upward) to pry the limiting plate 51 and the pull rod 41 upward, compressing the spring 42 and causing the vacuum bulb 39 to break, thus disconnecting the load current circuit system (the current transition circuit system remains conductive to ensure that the switching process is uninterrupted). When the circuit breaks the current, the arc is extinguished in the vacuum bulb.

[0069] In the S6.V1 vacuum arc extinguishing system, after the vacuum bulb 39 is disconnected and the arc is extinguished, the K1 current-carrying changeover contact 17 disengages from the conductive piece 53 that was initially in contact (the one that was first in contact) and moves toward another conductive piece 53.

[0070] S7. The insulating spindle 7 continues to rotate. After the K1 current-carrying changeover contact 17 contacts another conductive plate 53, one end of the lever 48 with cam 52 in the V1 vacuum arc extinguishing system disengages from the roller 46. As the spring 42 releases its energy and extends, it pushes the limiting plate 51 and the pull rod 41 downward. At the same time, the end of the lever 48 that is in contact with the limiting plate 51 also moves downward under the push of the limiting plate 51, causing the lever 48 to rotate. This causes the end of the lever 48 with cam 52 to move downward (to cooperate with the next roller 46). The pull rod 41 moves downward, causing the vacuum bulb 39 to close. Both the current transition circuit system and the load current circuit system are in the connected state, and the K2 transition changeover contact 16 and the K1 current-carrying changeover contact 17 are connected to the same conductive plate 53, completing one switching operation. Example 2

[0071] Since all the parts of the switching core 4 are assembled on one side of the insulated main shaft 7, the center of the switching core 4 shifts when it is lifted. In order to balance the center of gravity of the switching core 4 and guide it during assembly, this embodiment adds the following settings based on embodiment 1.

[0072] A counterweight 15 with a guiding function is installed at the bottom of the insulating spindle 7 of the switching core 4. The upper end of the counterweight 15 is fitted inside the bottom of the insulating spindle 7 and locked inside the insulating spindle 7 by multiple bolts. The lower end of the counterweight 15 is located outside the insulating spindle 7 and has a counterweight ring with an edge protruding from the insulating spindle 7 on its outer side. The insulating spindle 7 is cylindrical in shape, and the opening on the inner side of its lower end is flared, which facilitates the guiding function during assembly. The counterweight 15 is fitted outside the cylinder 50 of the oil chamber 1. A bearing 37 is installed inside the counterweight 15. The lower end of the bearing 37 (inner ring) is combined with the cylinder 50 of the oil chamber 1 to support the weight of the entire switching core 4. Example 3

[0073] To provide a housing for the moving contact and prevent it from being directly worn during operation, this embodiment adds the following features based on embodiment 1 or 2.

[0074] A protective shell 25 is fitted on the part of each moving contact 26 located in the mounting groove. The protective shell 25 is in direct contact with the clamping spring 24 and bears the pressure of the clamping spring 24. Example 4

[0075] In order to achieve the desired opening distance between the two moving contacts 26 in each moving contact group facing the inner wall of the oil chamber, and to avoid the opening distance being too small, the following settings are added to this embodiment based on embodiment 3.

[0076] A pin hole is vertically provided on the support member 33, and a positioning pin 32 located between the two moving contacts 26 is sleeved in the pin hole. The positioning pin 32 adjusts the opening distance of the moving contacts 26. Example 5

[0077] Similar to conventional disassembly switches, this embodiment also has an oil extraction pipe 5 installed in the oil chamber 1. The oil extraction pipe 5 is coaxially sleeved inside the insulating main shaft 7. The lower end of the oil extraction pipe 5 has a two-stage conical structure. The upper diameter of the upper cone is larger than its lower diameter, and the upper diameter of the lower cone is larger than its lower diameter. The lower diameter of the upper cone is equal to the upper diameter of the lower cone. There is a cylindrical transition section between the upper and lower cones. The upper side of the upper cone also has a cylindrical structure that mates with the inner wall of the cylinder 50 and the inner ring of the bearing 37, forming a multi-stage positioning structure. The lower end of the oil extraction pipe 5 rotates through the inner ring of the bearing 37 and is then assembled inside the cylinder 50. The oil extraction pipe 5 has a multi-stage positioning function.

[0078] When installing the switching core 4, the center of the switching core 4 does not coincide with the center of the oil chamber 1 (e.g.) Figure 7 As shown), primary positioning is first achieved using the sucker pipe 5. The lower end of the sucker pipe 5 is inserted into the cylinder 50. Then, the moving and stationary contacts of phase A of the switching core 4 are closed. Finally, the sucker pipe 5 is installed in place so that the moving and stationary contacts of phases A, B, and C are closed simultaneously. During positioning, the lower-stage cone at the lower end of the sucker pipe 5 first extends into the cylinder 50. Guided by its inclined surface, the cylindrical transition section is fitted into the cylinder 50. Then, the inclined surface of the lower-stage cone further guides the upper cylindrical structure to fit into and assemble into the cylinder 50, thus achieving primary positioning of the switching core 4 and the oil chamber 1.

[0079] Other aspects of this utility model that are not detailed herein are all conventional techniques known to those skilled in the art.

[0080] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0081] The scope of protection of this utility model is not limited to the technical solutions disclosed in the specific embodiments. Any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of this utility model shall fall within the scope of protection of this utility model.

Claims

1. An oil-immersed composite vacuum on-load tap changer, comprising an oil chamber and a switching core rotatably mounted within the oil chamber, characterized in that: The switching core includes an insulating spindle rotatably mounted in the oil chamber, and at least one switching mechanism fixed on the insulating spindle. Each switching mechanism includes an upper mounting plate, a lower mounting plate, a vacuum arc extinguishing system, a moving contact system, a transition resistor, and rollers; The upper mounting plate and the lower mounting plate are fixed to the insulating spindle from top to bottom; The vacuum arc extinguishing system is installed on the upper mounting plate and the lower mounting plate respectively at both ends, and includes a V1 vacuum arc extinguishing system and a V2 vacuum arc extinguishing system; The moving contact system is installed between the V1 vacuum arc extinguishing system and the V2 vacuum arc extinguishing system; The transition resistor is mounted on the lower mounting plate; The rollers are multiple and are rotatably installed on the inside of the oil chamber. The vacuum arc extinguishing system can cooperate with the rollers as the insulating spindle rotates, so that the vacuum arc extinguishing system can open and close.

2. The oil-immersed composite vacuum on-load tap changer according to claim 1, characterized in that: The moving contact system includes a neutral point lead-out moving contact, a K1 current-carrying changeover contact, and a K2 transition changeover contact; The neutral point lead-out moving contact is mounted on the upper mounting plate; the K1 current-carrying changeover contact and the K2 transition changeover contact are both fixed on the lower mounting plate, wherein the K2 transition changeover contact is located between the V2 vacuum arc extinguishing system and the K1 current-carrying changeover contact; The K1 current-carrying changeover contact, the V1 vacuum arc-extinguishing system, and the neutral point lead-out moving contact are connected in series in sequence; the K2 transition changeover contact, the transition resistor, the V2 vacuum arc-extinguishing system, and the neutral point lead-out moving contact are connected in series in sequence.

3. The oil-immersed composite vacuum on-load tap changer according to claim 2, characterized in that: At least one stationary contact system corresponding to the switching mechanism is provided on the oil chamber; Each stationary contact system includes a lead-out stationary contact mechanism and an input stationary contact mechanism; The lead-out stationary contact mechanism includes a conductive ring fixed to the inner wall of the oil chamber and a lead-out stationary contact fixed to the outer wall of the oil chamber and connected to the conductive ring; the conductive ring and the neutral point lead-out moving contact on the corresponding switching mechanism always maintain contact. The input stationary contact mechanism includes multiple input stationary contact groups arranged in a ring on the oil chamber. Each input stationary contact group includes a conductive sheet fixed on the inner wall of the oil chamber and an input stationary contact fixed on the outer wall of the oil chamber and connected to the conductive sheet. The conductive sheet maintains contact with the K1 current-carrying changeover contact and the K2 transition changeover contact respectively. Both the K1 current-carrying changeover contact and the K2 transition changeover contact can move to another position and contact another conductive sheet as the insulating spindle rotates.

4. The oil-immersed composite vacuum on-load tap changer according to claim 2, characterized in that: The neutral point lead-out moving contact, K1 current-carrying conversion contact, and K2 transition conversion contact are identical and each consists of a support member, a clamping spring, and at least one moving contact group. The support member is fixed to the corresponding upper and lower mounting plates, and mounting grooves are provided on the upper and lower sides of the support member. A vertical through hole is provided in the support member near the insulating spindle. Each moving contact group includes two moving contacts located in the upper and lower mounting grooves of the support member, respectively. The middle part of each moving contact is rotatably mounted in the mounting groove by a positioning pin. One end of the moving contact points to the oil chamber, and the other end points to the insulating spindle and is located above the vertical through hole. The clamping spring is set in the vertical through hole, and its two ends extend out of the vertical through hole and contact the two moving contacts respectively, so that the ends of the two moving contact groups away from the insulating spindle are brought closer to each other.

5. The oil-immersed composite vacuum on-load tap changer according to claim 4, characterized in that: A protective shell is fitted onto the part of each moving contact located in the mounting groove, and the protective shell is in direct contact with the clamping spring.

6. The oil-immersed composite vacuum on-load tap changer according to claim 4, characterized in that: The K2 transition contact has one moving contact group, while the neutral point lead-out moving contact and the K1 current-carrying transition contact each have two moving contact groups.

7. The oil-immersed composite vacuum on-load tap changer according to claim 1, characterized in that: A counterweight is installed at the bottom of the insulated spindle.

8. The oil-immersed composite vacuum on-load tap changer according to claim 1, characterized in that: The upper mounting plate is made of metal and is fixed to the outer wall of the insulating spindle by fastening bolts and a metal ring sleeved inside the insulating spindle; the lower mounting plate is made of insulating material and is fixed to the outer wall of the insulating spindle by fastening bolts and a support ring sleeved inside the insulating spindle.

9. The oil-immersed composite vacuum on-load tap changer according to claim 1, characterized in that: The V1 vacuum arc extinguishing system and the V2 vacuum arc extinguishing system have the same structure and both consist of a vacuum bulb, a guide, a pull rod, a limiting plate, a spring, a support, and a lever. The lower end of the vacuum bulb is mounted on the lower mounting plate. The guide is fixed to the top of the upper mounting plate and located directly above the vacuum bulb. The lower end of the pull rod is connected to the upper end of the vacuum bulb and can drive the vacuum bulb to open and close. The upper end of the pull rod moves through a pre-set mounting hole on the upper mounting plate and slides into a pre-set guide hole in the guide. The limiting plate is fixed on the pull rod and located between the vacuum bulb and the guide. The spring is sleeved on the outside of the pull rod and located in the mounting hole of the upper mounting plate. Its upper end contacts the bottom of the guide and its lower end contacts the top of the limiting plate. The support is fixed to the bottom of the upper mounting plate and located between the pull rod and the roller. The lever is rotatably mounted on the support. One end of the lever is sleeved on the pull rod and contacts the bottom of the limiting plate, and the other end is located below the roller and cooperates with the roller.

10. The oil-immersed composite vacuum on-load tap changer according to claim 9, characterized in that: A cam is fixed at one end of the lever that engages with the roller. When the cam moves to contact the roller, it is pressed down by the roller, causing the lever to rotate around the shaft. This causes the other end of the lever to pry the limiting plate and the pull rod upward, compressing the spring and breaking the vacuum bubble.

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