Tap switch electric mechanism for extra-high voltage converter transformer and control method

Abstract

The invention discloses an electric mechanism of an on-load voltage regulation tap-changer for an extra-high voltage converter transformer and a control method of the electric mechanism, and relates to the technical field of on-load tap-changels.The electric mechanism comprises a motor, a speed reduction assembly, a transmission assembly and a gear indication and protection assembly, the motor is connected to a driving shaft of the tap switch through the speed reduction assembly and the transmission assembly, and the gear indication and protection assembly is arranged on the transmission assembly and used for displaying a current gear and providing a protection function; the speed reduction assembly comprises an input shaft directly connected with the motor and an output shaft directly connected with the transmission assembly, and speed reduction transmission is carried out between the input shaft and the output shaft. The transmission assembly is connected with an output shaft of the speed reduction assembly and a driving shaft of the tap switch for synchronous rotation; and the gear indication and protection assembly is linked with the output shaft of the speed reduction assembly for control. According to the invention, the technical effects of improving the operation reliability of the voltage regulation tap switch, enhancing the safety and optimizing the gear adjustment precision are achieved.

Description

Technical Field

[0001] This application relates to the technical field of on-load tap changers, and in particular to an electric mechanism and control method for a tap changer used in an ultra-high voltage converter transformer. Background Technology

[0002] As a crucial voltage regulating device in power systems, the on-load tap changer of a converter transformer plays a key role in voltage regulation through its electric mechanism. The electric mechanism drives the transmission components to complete tap position changes, thereby achieving precise control of the grid voltage. With the development of ultra-high voltage technology, the performance requirements for the electric mechanism of the on-load tap changer are increasingly stringent, demanding not only high reliability but also stability over long periods. In existing technologies, several conventional methods are typically used to address various issues in tap position changes: first, optimizing the motor mounting method, such as adding nuts and washers or improving the installation structure, to prevent motor loosening; second, regularly lubricating and rust-preventing the transmission rod to avoid mechanical jamming caused by corrosion; third, designing multiple protection devices, such as manual power-off protection, phase sequence protection, and limit protection, to ensure safe operation; and fourth, employing traditional relay-based control logic, utilizing contactors, limit switches, and other components to achieve tap position adjustment and protection functions. These methods improve the reliability of the electric mechanism to some extent, but there is still room for improvement. However, a common problem in existing technologies is that when the tap changer is adjusted, slippage can easily occur due to insufficient precision in the fit between mechanical components or delayed response of protection devices, meaning the actual tap position does not match the target tap position. This defect not only affects voltage regulation accuracy but can also lead to equipment damage and, in severe cases, even endanger the safe operation of the power grid. Therefore, improving the accuracy and stability of the electric mechanism during tap adjustment has become an urgent technical problem to be solved. Summary of the Invention

[0003] The purpose of this application is to overcome the above-mentioned technical problems and provide an electric mechanism and control method for a tap changer used in an ultra-high voltage converter transformer.

[0004] On the one hand, this application discloses an electric mechanism for a tap changer in an ultra-high voltage converter transformer.

[0005] An electric mechanism for a tap changer in an ultra-high voltage converter transformer includes a motor, a reduction gear assembly, a transmission assembly, and a tap position indicator and protection assembly. The motor is controlled by a microcontroller and is connected to the drive shaft of the tap changer through the reduction gear assembly and the transmission assembly. The tap position indicator and protection assembly is used to display the current tap position and provide protection functions. The reduction assembly includes an input shaft directly connected to the motor and an output shaft directly connected to the transmission assembly, with the input shaft and the output shaft performing reduction transmission; the transmission assembly connects the output shaft of the reduction assembly and the drive shaft of the tap changer for synchronous rotation; the gear position indicator and protection assembly is linked to the output shaft of the reduction assembly.

[0006] By adopting the above technical solution, the entire electric mechanism is modularly designed into multiple components, improving the reliability and maintenance convenience of the on-load tap changer drive system. Using a microcontroller to control the motor enhances control accuracy and response speed, reduces the failure rate, and helps ensure the precision of the electric mechanism's direct drive of the tap changer's drive shaft. The gear position indicator and protection components are directly connected to the output shaft of the reduction gear assembly, and the output shaft rotates synchronously with the tap changer's drive shaft. This allows the tap changer's gear position switching action to be directly transmitted to the gear position indicator and protection components, thereby synchronously driving the gear position display and switching, and accurately monitoring the gear position switching status, enhancing the safety of the drive system.

[0007] Preferably, the transmission assembly includes a transmission shaft, a coupling, and a connecting shaft. The transmission shaft is a polygonal prism shaft. The coupling includes two symmetrical clamps, which are detachably fixed by bolts. When the two clamps are joined, they form a polygonal hole that matches the contour of the transmission shaft. The end of the clamp away from the transmission shaft has a through slot. The end of the connecting shaft is configured as a spherical connector that rotates with the clamps. Two coaxial connecting rods are provided on the spherical connector corresponding to the slots on the two clamps. The connecting rods are inserted into the slots and slide with them. The axis of the connecting rods is perpendicular to the axis of the connecting shaft. A pulley is provided between the transmission shaft and the output shaft for transmission.

[0008] By adopting the above technical solution, a highly efficient transmission connection between the motor output shaft and the switch body drive shaft is achieved. Using a pulley to reduce the speed of the motor output shaft effectively reduces noise during transmission, ensures smooth transmission, and lowers the failure rate. Employing a prism shaft as the transmission shaft ensures synchronous rotation between the coupling and the transmission shaft. Simultaneously, the connecting shaft uses a ball joint and a slotted connecting rod structure, combined with the slotted groove on the coupling clamp, ensuring that while the connecting shaft and coupling rotate synchronously in the circumferential direction, the axes of the coupling and the connecting shaft can adaptively offset, reducing installation difficulty, minimizing stress damage within the transmission components, making the transmission components less prone to damage, and ensuring precise transmission.

[0009] Preferably, the deceleration assembly includes a deceleration housing and a hand-cranked power-off protection component. The hand-cranked power-off protection component includes a hand crank shaft rotatably mounted on the deceleration housing, a first hand-cranked bevel gear coaxially fixed on the hand crank shaft, and a second hand-cranked bevel gear coaxially fixed on the output shaft. The first hand-cranked bevel gear and the second hand-cranked bevel gear mesh with each other. The hand crank shaft slides axially with the deceleration housing. A first elastic element is provided between the hand crank shaft and the deceleration housing. The first elastic element drives the first hand-cranked bevel gear away from the second hand-cranked bevel gear.

[0010] By adopting the above technical solution and installing a hand-cranked power-off protection component, operators can manually control the tap changer's position switching using a dedicated handle from the outside. When the on-load tap changer stops due to a fault or other factors, the switch position may be in the process of switching or needs to be switched. If the on-load tap changer is not switched to the correct position, it will affect its maintenance and may even lead to more serious accidents. The hand-cranked power-off protection component facilitates the maintenance of the on-load tap changer, better prevents maintenance in various fault scenarios, and improves safety. When the operator is not operating the hand-cranked power-off protection component, the hand crank shaft slides away from the second hand crank bevel gear under the action of the first elastic element, separating the first and second hand crank bevel gears and preventing the hand crank shaft from affecting the normal operation of the electric mechanism.

[0011] Preferably, the reduction housing is provided with mounting holes for mounting a hand crank shaft. The hand crank shaft is rotatably engaged with the mounting holes via bearings mounted at both ends. The hand crank shaft is slidably engaged with the inner rings of the bearings. A retaining ring is installed on the hand crank shaft for axial positioning. A sliding hole is coaxially formed at the end of the hand crank shaft away from the first hand crank bevel gear. A limiting hole communicating with the sliding hole is formed through the side wall of the hand crank shaft. A limiting ball is slidably installed in the limiting hole. A limiting rod is slidably installed in the sliding hole. A second elastic element in a compressed state is provided between the limiting rod and the bottom of the sliding hole. The side wall of the limiting rod is provided with an arc-shaped groove corresponding to the limiting ball, and the minimum vertical clearance between the bottom of the arc-shaped groove and the bearing of the hand crank shaft is in clearance fit with the limiting ball; the side wall of the mounting hole is provided with a clearance groove corresponding to the limiting ball to allow the limiting ball to completely disengage from the arc-shaped groove; a limiting pin is fixed in the sliding hole, and a limiting elongated hole is opened on the limiting rod corresponding to the limiting pin to limit the sliding range of the limiting rod, and the end of the limiting rod is always located in the sliding hole; a vertical groove is opened at the end of the hand crank shaft away from the first hand crank bevel gear, penetrating the sliding hole, and the end of the limiting rod is always located in the vertical groove.

[0012] By adopting the above technical solution, misoperation is effectively prevented, and the safety and reliability of the electric mechanism are improved. When the operator is not operating the mechanism, the hand crank shaft slides away from the second hand crank bevel gear under the action of the first elastic element, separating the first and second hand crank bevel gears and preventing the hand crank shaft from affecting the normal operation of the electric mechanism. Meanwhile, the limit rod slides away from the hand crank shaft under the action of the second elastic element. The arc-shaped groove on the limit rod abuts against the limit ball, causing the limit ball to press against the inner ring wall of the bearing, thereby restricting the overall sliding of the hand crank shaft. Furthermore, since the limit rod is located within the sliding hole of the hand crank shaft, it cannot be operated without a special tool, effectively preventing misoperation. Using a special tool capable of engaging the limit rod, the tool passes through the slot and engages the limit rod. While moving, it forms a circumferential limit with the hand crank shaft. The limit rod is pushed, and the limiting ball's abutment and limiting state loosens. Under the elastic force of the second elastic element, the hand crank shaft slides towards the second hand crank bevel gear. When the limit ball moves below the clearance groove, it is pushed into the clearance groove. The limit rod is no longer limited in its movement range by the limit ball, and the hand crank tool can be fully inserted into the slot. After the first hand crank bevel gear is pressed on the second hand crank bevel gear, if the two are not meshed, simply rotate the hand crank shaft normally. After the two are rotated to the meshing position, the first hand crank bevel gear will automatically push forward to complete the meshing. The operation is simple and convenient.

[0013] Preferably, the gear position indicator and protection component includes a linkage component and a signal feedback component. The linkage component is connected to one end of the output shaft of the reduction assembly for linkage and drives the mechanism in the signal feedback component to perform action signal feedback. The linkage component includes a linkage housing, a primary drive shaft, a secondary worm gear, and a tertiary worm wheel. The primary drive shaft and the secondary worm gear are rotatably mounted in the linkage housing. The upper end of the primary drive shaft extends out of the linkage housing and is coaxially fixed with the output shaft of the reduction assembly. A 1:1 gear pair is provided between the primary drive shaft and the secondary worm gear for constant speed transmission. The secondary worm gear meshes with the tertiary worm wheel, and the transmission ratio is the same as the transmission ratio of the worm wheel box at the top of the tap changer.

[0014] Preferably, the linkage component further includes a first driven shaft, which is rotatably mounted on the linkage housing, and a third-stage worm gear is fixed on the first driven shaft; The signal feedback component includes a functional housing and an action signal feedback component. The action signal feedback component includes a trigger wheel coaxially fixed on a first driven shaft and a first limit switch disposed below the trigger wheel. The first limit switch is fixed on the functional housing. Two clearance planes are provided on the circumference of the trigger wheel, and the two clearance planes are parallel to each other. The circumferential surface of the trigger wheel presses the first limit switch, and the press on the first limit switch is released when the clearance plane of the trigger wheel is aligned with the first limit switch. Two pairs of clearance planes are provided along the axial direction of the trigger wheel, and two first limit switches are provided corresponding to the two pairs of clearance planes.

[0015] Preferably, the signal feedback component includes a functional box and a panel installed on the side of the functional box away from the linkage component. A gear position pointer and a rotation position pointer are rotatably mounted on the panel. Different gear positions are set on the panel corresponding to the gear position pointer, and different circumferential position scales are set on the panel corresponding to the rotation position pointer. The rotation axes of the gear position pointer and the rotation position pointer are coaxial. The linkage component also includes a second driven shaft, which is rotatably mounted on the linkage housing. A three-stage worm gear is fixed on the second driven shaft. The second driven shaft passes through the functional housing and panel of the signal feedback component. The rotation position pointer is fixed at the end of the second driven shaft. A driven shaft sleeve is coaxially fitted at one end of the second driven shaft near the panel. The end of the driven shaft sleeve is fixed to the gear pointer insert. A drive disk is coaxially rotatably mounted at one end of the second driven shaft near the driven shaft sleeve. One end of the driven shaft sleeve is coaxially inserted and fixed to the drive disk, and the other end of the driven shaft sleeve is rotatably inserted to the panel. A gear reduction assembly is provided between the drive disk and the second driven shaft for speed reduction transmission.

[0016] Preferably, the linkage component further includes a third driven shaft, on which a swing block is fixed, and a lever is provided on the side of the drive disk near the swing block to actuate the swing block; a counterweight is fixed on the third driven shaft, and the counterweight ensures that the swing block is always on the rotation trajectory of the lever when no external force is applied. The signal feedback component also includes a first gear signal feedback component, which includes a straight trigger rod fixed on the third driven shaft, two micro switches disposed at both ends of the trigger rod, and two second limit switches disposed at both ends of the trigger rod. The micro switches and the second limit switches are arranged along the axial direction of the third driven shaft, and the trigger rod has two corresponding micro switches and two limit switches.

[0017] Preferably, the second gear signal feedback component includes a signal disk coaxially arranged with the driven shaft sleeve and a trigger disk coaxially fixed on the driven shaft sleeve; the signal disk is coaxially arranged with a conductive ring and a circular array of contact points, the distribution of which corresponds to the central angle of the gear position on the panel; a contact bridge is fixed on the side of the trigger disk near the signal disk, the contact bridge being a conductive metal plate, and elastic contact plates that slide against the conductive ring and contact points respectively at both ends of the contact bridge. A control method for an electric mechanism of a tap changer for an ultra-high voltage converter transformer includes the following steps: S1, receiving a gear adjustment command, starting the motor to rotate forward or reverse, driving the drive shaft of the switch body to rotate through the transmission component to complete the gear adjustment, and simultaneously updating the gear indicator and the display of the protection component through a one-to-one correspondence of signal contacts, BCD code, or analog output; S2. Before starting the motor, check whether the surge protection device at the power input port is working properly. S3, during gear adjustment, monitor whether the mechanical return time of contactors K2 / K3 exceeds the set threshold; S4. After the adjustment is completed, monitor whether the return time of the holding contact in S12 meets the requirements.

[0018] In summary, this application includes at least one of the following beneficial technical effects: 1. By using a modularly designed motor and microcontroller control, the control accuracy and response speed of the electric mechanism are improved, effectively avoiding the slippage phenomenon caused by traditional relay control logic, and improving the accuracy of tap changer gear adjustment; 2. The gear indicator and protection components integrate manual power-off protection and remote signal feedback detection functions, ensuring that the equipment can stop in time or take protective measures in abnormal situations, thereby enhancing the reliability and safety of the electric mechanism operation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a schematic diagram of the overall structure of the deceleration assembly; Figure 3 This is a schematic diagram of the connection relationship of the transmission components; Figure 4 Schematic diagram of the internal structure of the deceleration assembly; Figure 5 This is a structural diagram of a hand-cranked power-off protection component; Figure 6 yes Figure 5 A magnified view of area A in the middle; Figure 7 This is a schematic diagram of the tap changer drive structure in this embodiment; Figure 8 This is a schematic diagram of the gear position indicator and protection components in this embodiment; Figure 9 yes Figure 8 BB section view; Figure 10 yes Figure 8 CC section view; Figure 11 yes Figure 8 DD sectional view; Figure 12 This is a schematic diagram of the drive structure on the second driven shaft (the position of the first internal gear ring). Figure 13 This is a schematic diagram of the internal structure of the signal feedback component; Figure 14 yes Figure 13 Enlarged view of region E in the middle; Figure 15 This is a schematic diagram of the second gear signal feedback component. Figure 1 ; Figure 16 This is a schematic diagram of the second gear signal feedback component. Figure 2 ; Figure 17 This is a schematic diagram illustrating the principle of adding isolation measures to the power supply.

[0020] Reference numerals: 1. Switch body; 11. Worm gear box; 12. Toggle lever; 13. Grooved wheel disc; 2. Mechanism housing; 3. Motor; 4. Reduction assembly; 41. Reduction housing; 42. Input shaft; 43. Output shaft; 44. Belt; 45. Small diameter pulley; 46. Large diameter pulley; 47. Hand-cranked power-off protection component; 471. Hand-cranked shaft; 4711. Sliding hole; 4712. Limiting hole; 4714. Pressure relief hole; 4715. Vertical groove; 472. First hand-cranked bevel gear; 473. Second hand-cranked bevel gear; 474. First elastic element; 475. Limit ball; 476. Limit rod; 4761. Arc groove; 4762. Limit elongated hole; 477. Second elastic element; 48. Limit pin; 49. Insert coupling; 5. Transmission assembly; 48. Mounting base; 481. Mounting hole; 482. Clearance groove; 51. Drive shaft; 52. Coupling; 521. Clamp; 522. Slotted groove; 53. Connecting shaft; 531. Ball joint; 532. Connecting rod; 54. Steering gear box; 6. Controller; 7. Gear position indicator and protection assembly; 8. Linkage component; 81. Linkage box body; 82. First stage 83. Drive shaft; 84. Second-stage worm gear; 85. Third-stage worm gear; 86. First driven shaft; 87. Trigger wheel; 88. Clearance plane; 89. First limit switch; 80. Second driven shaft; 81. First internal gear ring; 82. First planetary gear; 863. Second internal gear ring; 864. Second planetary gear; 865. Support arm; 866. Drive gear; 867. Drive disc; 868. Pulley; 87. Third driven shaft; 871. Swing block; 872. Counterweight; 873. Trigger rod; 874. Micro switch; 875. Second stroke 88. Switch; 9. Driven shaft sleeve; 10. Signal feedback component; 11. Panel; 12. Gear position pointer; 13. Rotation position pointer; 14. Counter; 15. Functional box; 16. Action signal feedback component; 17. First gear signal feedback component; 18. Second gear signal feedback component; 19. Signal disk; 10. Outer conductive ring; 11. External electrical contact; 12. Inner conductive ring; 13. Internal electrical contact; 14. Internal electrical contact; 15. Trigger disk; 16. External bridge; 17. Internal bridge; 18. Partition; 19. Disc component; 10. Lithium battery. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only possible technical implementations of the present invention and not all possible implementations. Those skilled in the art can obtain other embodiments in conjunction with the embodiments of the present invention without creative effort, and these embodiments are also within the protection scope of the present invention.

[0022] An electric mechanism for a tap changer in an ultra-high voltage converter transformer, reference Figure 1 The switch body 1 comprises a rectangular housing 2, a motor 3, a reduction gear assembly 4, a transmission assembly 5, a controller 6, and a gear position indicator and protection assembly 7. The controller 6 is fixed inside the housing 2 with screws. The motor 3 is a stepper motor, which is precisely controlled by a microcontroller. The motor 3 is connected to the drive shaft of the switch body 1 via the reduction gear assembly 4 and the transmission assembly 5. The gear position indicator and protection assembly 7 is mounted on the transmission assembly 5 and is used to display the current gear position and provide protection. A rechargeable lithium battery 10 is also installed inside the housing 2 to power the various electric mechanisms and prevent accidental power outages.

[0023] The transmission assembly 5 includes a drive shaft 51, a coupling 52, a connecting shaft 53, and a steering gear box 54. The drive shaft 51 is a quadrilateral prism shaft, and the steering gear box 54 is a bevel gear box.

[0024] refer to Figure 2 and Figure 3 The coupling 52 includes two symmetrical clamps 521, which are detachably fixed by bolts. When the two clamps 521 are joined together, they form a quadrilateral hole that matches the contour of the drive shaft 51. The end of the clamp 521 away from the drive shaft 51 is provided with a slot 522 that passes through the clamp 521. The end of the connecting shaft 53 is provided with a spherical connector 531 that rotates with the clamp 521. The spherical connector 531 is provided with two coaxial connecting rods 532 corresponding to the slots 522 on the two clamps 521. The connecting rods 532 are inserted into the slots 522 and slide with the slots 522. The axis of the connecting rods 532 is perpendicular to the axis of the connecting shaft 53.

[0025] refer to Figure 2 and Figure 4The reduction assembly 4 includes a reduction housing 41, an input shaft 42 directly connected to the motor 3, an output shaft 43 directly connected to the transmission assembly 5, and a belt 44 pulley transmission structure disposed between the input shaft 42 and the output shaft 43. The input shaft 42 is coaxially fixed on the rotating shaft of the motor 3, and the motor 3 is fixed to the reduction housing 41 with bolts. A small-diameter pulley 45 is coaxially fixed on the input shaft 42. The output shaft 43 is rotatably mounted in the reduction housing 41 with bearings. A large-diameter pulley 46 is coaxially fixed on the output shaft 43. A belt 44 is disposed between the two pulleys for transmission. One end of the output shaft 43 is connected and fixed to the transmission assembly 5 through a coupling 52, and the other end of the output shaft 43 is linked with the gear position indicator and protection assembly 7 through a meshing wheel structure.

[0026] refer to Figure 2 and Figure 5 The deceleration assembly 4 also includes a hand-cranked power-off protection component 47. The hand-cranked power-off protection component 47 includes a hand-cranked shaft 471 rotatably mounted on the deceleration housing 41, a first hand-cranked bevel gear 472 coaxially fixed on the hand-cranked shaft 471, and a second hand-cranked bevel gear 473 coaxially fixed on the output shaft 43. The first hand-cranked bevel gear 472 and the second hand-cranked bevel gear 473 mesh with each other. The hand-cranked shaft 471 slides with the deceleration housing 41 and slides axially. A first elastic element 474 is provided between the hand-cranked shaft 471 and the deceleration housing 41. The first elastic element 474 drives the first hand-cranked bevel gear 472 away from the second hand-cranked bevel gear 473.

[0027] The reduction housing 41 is bolted to a mounting base 48, which has a through mounting hole 481 for mounting a hand crank shaft 471. The hand crank shaft 471 is rotatably engaged with the mounting hole 481 by bearings at both ends, and the hand crank shaft 471 slides against the inner ring of the bearing. A retaining ring is installed on the hand crank shaft 471 for axial positioning. A sliding hole 4711 is coaxially formed at the end of the hand crank shaft 471 away from the first hand crank bevel gear 472. A small-diameter pressure relief hole 4714 is provided at the bottom of the sliding hole 4711, penetrating the hand crank shaft 471. A limiting hole 4712 communicating with the sliding hole 4711 is formed on the side wall of the hand crank shaft 471. A limiting ball 475 is slidably installed in the limiting hole 4712, and a limiting rod 476 is slidably installed in the sliding hole 4711. A positioning rod 476 is provided between the limiting rod 476 and the bottom of the sliding hole 4711. The second elastic element 477 in the compressed state has an arc-shaped groove 4761 on the side wall of the limiting rod 476 corresponding to the limiting ball 475. The minimum vertical clearance between the bottom of the arc-shaped groove 4761 and the bearing of the hand crank shaft 471 is clearance-fitted with the limiting ball 475. The side wall of the mounting hole 481 is provided with a relief groove 482 corresponding to the limiting ball 475 to allow the limiting ball 475 to completely disengage from the arc-shaped groove 4761. A limiting pin 48 is fixed in the sliding hole 4711. A limiting elongated hole 4762 is opened on the limiting rod 476 corresponding to the limiting pin 48 to limit the sliding range of the limiting rod 476. The end of the limiting rod 476 is always located in the sliding hole 4711. A vertical groove 4715 is opened at the end of the hand crank shaft 471 away from the first hand crank bevel gear 472, penetrating the sliding hole 4711. The end of the limiting rod 476 is always located in the vertical groove 4715.

[0028] refer to Figure 7 The electric mechanism for a tap changer used in an ultra-high voltage converter transformer disclosed in this application includes a worm gear box 11 connected and linked to the transmission assembly 5, a lever 12 coaxially fixed on the shaft of the worm gear box 11, and a slotted wheel 13 cooperating with the lever 12. Compared with a transmission tap changer, the spring-loaded mechanism is eliminated, and the gear shifting action is synchronized with the action of the motor 3. There is no lag in the gear shifting action, which helps to more accurately and in real-time monitor the gear shifting status and position.

[0029] refer to Figure 8The gear position indicator and protection component 7 includes a linkage component 8 and a signal feedback component 9. The linkage component 8 is connected to the lower end of the output shaft 43 of the reduction component 4 for linkage, driving multiple shafts to rotate. The signal feedback component 9 is driven by the multiple shafts of the linkage component 8 to realize functions such as gear position indication and protection. The signal feedback component 9 includes a function box 92 and a panel 91 installed on the side of the function box 92 away from the linkage component 8. A gear position pointer 911, a rotation position pointer 912, and a counter 913 are rotatably mounted on the panel 91. Different gear position scales are set on the panel 91 corresponding to the gear position pointer 911, and different circumferential position scales are set on the panel 91 corresponding to the rotation position pointer 912.

[0030] refer to Figure 8 and Figure 9 The linkage component 8 includes a linkage housing 81, a primary drive shaft 82, a secondary worm gear 83, and a tertiary worm wheel 84. The primary drive shaft 82 and the secondary worm gear 83 are rotatably mounted in the linkage housing 81 using bearings. The upper end of the primary drive shaft 82 extends out of the linkage housing 81 and is coaxially fixed to the output shaft 43 of the reduction assembly 4 using a plug-in coupling 49. A 1:1 gear pair is provided between the primary drive shaft 82 and the secondary worm gear 83 for constant speed transmission. There are two tertiary worm wheels 84, one above the other, distributed on both sides of the secondary worm gear 83. The two secondary worm wheels drive the first driven shaft 85 and the second driven shaft 86 respectively. The worm gear transmission ratio in the linkage component 8 is the same as the worm gear transmission ratio in the tap changer worm gear box 11 to ensure synchronous operation.

[0031] refer to Figure 10 and Figure 11 The second driven shaft 86 is rotatably mounted on the linkage housing 81 by a bearing. The second driven shaft 86 passes through the functional housing 92 and panel 91 of the signal feedback component 9. The rotation position pointer 912 is fixed to the end of the second driven shaft 86. This transmission arrangement allows the rotation position pointer 912 and the lever 12 of the top drive mechanism of the tap changer to rotate synchronously, so as to understand the switching status of the on-load tap changer in real time and accurately.

[0032] refer to Figure 11 The second driven shaft 86 is coaxially fitted with a driven shaft sleeve 88 at one end near the panel 91, and the end of the driven shaft sleeve 88 is fixed to the gear pointer 911. The second driven shaft 86 is coaxially fixed with a drive disk 867 by a bearing at one end near the driven shaft sleeve 88, and one end of the driven shaft sleeve 88 is coaxially inserted and fixed to the drive disk 867. The other end of the driven shaft sleeve 88 is rotatably inserted into the panel 91.

[0033] refer to Figure 11 and Figure 12A drive gear 866 is coaxially fixed on the second driven shaft 86, and a pair of first planetary gears 862 are arranged around the drive gear 866. A support arm 865 is rotatably mounted on the second driven shaft 86 by bearings, and the two first planetary gears 862 are respectively rotatably mounted at both ends of the support arm 865. A meshing first internal gear ring 861 is arranged on the outer side of the two first planetary gears 862, and the first internal gear ring 861 is fixed to the linkage housing 81 with screws. A second planetary gear 864 is coaxially fixed on the side of the first planetary gears 862 near the drive disk 867. A meshing second internal gear ring 863 is arranged on the outer periphery of the two second planetary gears 864. The second planetary gears 864 rotate with the first planetary gears 862, and thus the second planetary gears 864 drive the second internal gear ring 863 to rotate. The second internal gear ring 863 is coaxially fixed to the drive disk 867 with bolts.

[0034] The drive gear 866, the first planetary gear 862, the first internal gear ring 861, the second planetary gear 864, the second internal gear ring 863, and the drive disk 867 are combined to form a reduction transmission mechanism coaxially arranged with the second driven shaft 86. Corresponding to the gear switching of the on-load tap changer, whenever the on-load tap changer switches to a gear, the drive disk 867 drives the gear pointer 911 to rotate by one gear angle (gear scale on the panel 91), so that the operator can intuitively see the status of the on-load tap changer from the drive mechanism.

[0035] refer to Figure 13 The signal feedback component 9 also includes an action signal feedback component 93, a first gear signal feedback component 94, and a second gear signal feedback component 95, which are disposed in the function box 92.

[0036] refer to Figure 14The action signal feedback component 93 includes a trigger wheel 851 coaxially fixed on the first driven shaft 85 and a first limit switch 853 disposed below the trigger wheel 851. The first limit switch 853 is fixed on the function box 92. Two clearance planes 852 are provided on the circumference of the trigger wheel 851. The two clearance planes 852 are parallel to each other (central angle is 180 degrees). The circumferential surface of the trigger wheel 851 will press the first limit switch 853. When the clearance plane 852 of the trigger wheel 851 is directly opposite the first limit switch 853, the press on the first limit switch 853 is released. There are two pairs of clearance planes 852 along the axial direction of the trigger wheel 851. The first limit switch 853 is provided with two first limit switches 853 corresponding to the two pairs of clearance planes 852. The first driven shaft 85 rotates synchronously with the rotation of the drive lever 12 inside the tap changer, and the two clearance planes 852 on the trigger wheel 851 correspond to the two positions of the rest point and the switching midpoint of the lever 12. The signal changes of the trigger wheel 851 pressing and releasing the first limit switch 853 can be used to remotely monitor the switching status of the tap changer and count the switching of the tap changer.

[0037] refer to Figure 12 and Figure 14 A swing block 871 is fixed on the third driven shaft 87, and a lever 868 for actuating the swing block 871 is provided on the side of the drive disc 867 near the swing block 871. A counterweight 872 is fixed on the third driven shaft 87, and the counterweight 872 maintains the circumferential position of the third driven shaft 87, so that the swing block 871 is always on the rotation trajectory of the lever 868 when no external force is applied. The first gear signal feedback component 94 includes a straight trigger rod 873 fixed on the third driven shaft 87, two micro switches 874 provided at both ends of the trigger rod 873, and two second limit switches 875 provided at both ends of the trigger rod 873. The micro switches 874 and the second limit switches 875 are arranged along the axial direction of the third driven shaft 87, and the trigger rod 873 has two corresponding micro switches 874 and second limit switches 875. When the toggle block 868 rotates with the drive disc 867 to move the swing block 871, the third driven shaft 87 rotates, and the trigger rod 873 rotates to trigger the micro switch 874 and the limit switch. When the toggle block 868 moves the swing block 871 from a stationary direction, it will drive the trigger rod 873 to rotate in different directions, thereby triggering the micro switch 874 and the limit switch on different sides. The signal emitted in this way can not only count the trigger signals, but also identify the direction of the tap changer.

[0038] refer to Figure 15The second gear signal feedback component 95 includes a signal disk 96 coaxially arranged with the driven shaft sleeve 88 and a trigger disk 97 coaxially fixed on the driven shaft sleeve 88. Two signal disks 96 are provided, both of which are sleeved on the second driven shaft 86. The two signal disks 96 are located on both sides of the trigger disk 97. The two signal disks 96 are fixed to the functional box 92 with long bolts. The signal disks 96 are coaxially arranged with conductive rings and circular arrayed electrical contacts. The distribution of the electrical contacts corresponds to the central angle of the gear position on the panel 91. There are two sets of conductive rings and electrical contacts, which are respectively an outer conductive ring 961, an outer electrical contact 962, an inner conductive ring 963, and an inner electrical contact 964 according to their distribution positions. The inner conductive ring 963 has a smaller diameter than the outer conductive ring 961 and is located inside the outer conductive ring 961. The trigger plate 97 is fixed with screws on both sides with a bridge. The bridge is a conductive metal plate. The two ends of the bridge are provided with elastic contact plates that slide against the conductive ring and the contact point respectively, so that the conductive ring is connected to the contact points in different directions, outputting different electrical signals and thus displaying different gears. The bridge is provided with an external bridge 971 and an internal bridge 972 corresponding to the two sets of conductive rings and contact points.

[0039] The second-position signal feedback component 95 has two partitions 98 on the side near the panel 91, and a disc 99 is disposed between the two partitions 98. The disc 99 is coaxially fixed to the second driven shaft 86, and the partitions 98 have clearance holes corresponding to the second driven shaft 86. The partitions 98 and the signal disc 96 are fixed to the functional box 92 with the same long bolt, and sleeves are provided between them for support.

[0040] refer to Figure 17 A surge suppression circuit is added at the DC power input as a power isolation device to suppress surges. This isolation device can withstand surge voltages up to 4kV, thus protecting the electric mechanism from external interference. The voltage rating of the original surge protection component (varistor) at the power input port is reduced from 470V to 390V. In the event of a momentary surge, the interference voltage is reduced to around 390V, ensuring that the power control chip (with a withstand voltage of 750V) is protected from high-voltage surges and enhancing the electromagnetic interference immunity of the electric mechanism.

[0041] The implementation principle of this embodiment is as follows: Through modular design, the motor 3, reduction gear assembly 4, transmission assembly 5, gear position indicator, and protection assembly 7 are integrated into one unit, improving the coordination accuracy and response speed between the components. By optimizing the design of the transmission assembly 5, energy loss during transmission is reduced, improving overall efficiency. These improvements not only enhance the accuracy and stability of the electric mechanism but also extend the service life of the equipment, representing a significant improvement and contribution to existing technology.

[0042] A control method for the electric mechanism of a tap changer in an ultra-high voltage converter transformer includes the following steps: S1 receives the gear adjustment command, starts the motor 3 to rotate forward or reverse, drives the switch body drive shaft to rotate through the transmission component 5 to complete the gear adjustment, and updates the gear indicator and the display of the protection component 7 through one-to-one corresponding signal contacts, BCD code or analog output.

[0043] S2. Before starting motor 3, check whether the surge protection device at the power input port is working properly.

[0044] S3, during gear adjustment, monitor whether the mechanical return time of contactors K2 / K3 exceeds the set threshold.

[0045] S4. After the adjustment is completed, monitor whether the return time of the holding contact in S12 meets the requirements.

[0046] The implementation principle of this embodiment is as follows: by introducing a control method, comprehensive monitoring and management of the electric mechanism is achieved. From checking the surge protection components at the power input port, to monitoring the contactor return time and S12 holding contact return time during gear adjustment, and then to the braking of the brake disc after gear adjustment, a complete closed-loop control system is formed. These measures not only improve the accuracy and stability of the electric mechanism, but also effectively prevent gear slippage.

[0047] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An electric mechanism for a tap changer in an ultra-high voltage converter transformer, characterized in that, It includes a motor (3), a reduction assembly (4), a transmission assembly (5), and a gear position indicator and protection assembly (7). The motor (3) is controlled by a microcontroller. The motor (3) is connected to the drive shaft of the tap changer through the reduction assembly (4) and the transmission assembly (5). The gear position indicator and protection assembly (7) is set on the transmission assembly (5) and is used to display the current gear position and provide protection function. The deceleration assembly (4) includes an input shaft (42) directly connected to the motor (3) and an output shaft (43) directly connected to the transmission assembly (5). The input shaft (42) and the output shaft (43) perform deceleration transmission. The transmission assembly (5) connects the output shaft (43) of the deceleration assembly (4) and the drive shaft of the tap changer to rotate synchronously. The gear position indicator and protection assembly (7) is linked with the output shaft (43) of the deceleration assembly (4) for control.

2. The electric mechanism for tap changer of UHV converter transformer according to claim 1, characterized in that, The transmission assembly (5) includes a transmission shaft (51), a coupling (52), and a connecting shaft (53). The transmission shaft (51) is a polygonal prism shaft. The coupling (52) includes two symmetrical clamps (521), which are detachably fixed with bolts. After the two clamps (521) are joined together, they form a polygonal hole that matches the contour of the transmission shaft (51). At the end of the clamp (521) away from the transmission shaft (51), there is a through slot (522) through the clamp (521). The connecting shaft (53) 3) The end is configured as a spherical connector (531) that rotates with the clamp (521). The spherical connector (531) is provided with two coaxial connecting rods (532) corresponding to the slots (522) on the two clamps (521). The connecting rods (532) are inserted into the slots (522) and slide with the slots (522). The axis of the connecting rods (532) is perpendicular to the axis of the connecting shaft (53). A belt (44) pulley is provided between the transmission shaft (51) and the output shaft (43) for transmission.

3. The electric mechanism for tap changer of UHV converter transformer according to claim 1, characterized in that, The deceleration assembly (4) includes a deceleration housing (41) and a hand-cranked power-off protection component (47). The hand-cranked power-off protection component (47) includes a hand crank shaft (471) rotatably mounted on the deceleration housing (41), a first hand-cranked bevel gear (472) coaxially fixed on the hand crank shaft (471), and a second hand-cranked bevel gear (473) coaxially fixed on the output shaft (43). The first hand-cranked bevel gear (472) and the second hand-cranked bevel gear (473) mesh with each other. The hand crank shaft (471) slides with the deceleration housing (41) and slides axially. A first elastic element (474) is provided between the hand crank shaft (471) and the deceleration housing (41). The first elastic element (474) drives the first hand-cranked bevel gear (472) away from the second hand-cranked bevel gear (473).

4. The electric mechanism for tap changer of UHV converter transformer according to claim 3, characterized in that, The reduction housing (41) is provided with a mounting hole (481) for mounting a hand crank shaft (471). The hand crank shaft (471) is rotatably engaged with the mounting hole (481) by bearings mounted at both ends. The hand crank shaft (471) slides with the inner ring of the bearing. A retaining ring is installed on the hand crank shaft (471) for axial positioning. A sliding hole (4711) is coaxially provided at the end of the hand crank shaft (471) away from the first hand crank bevel gear (472). The hand crank shaft (471) has a limiting hole (4712) that communicates with the sliding hole (4711) through its side wall. A limiting ball (475) is slidably installed in the limiting hole (4712), and a limiting rod (476) is slidably installed in the sliding hole (4711). A second elastic element (477) in a compressed state is provided between the limiting rod (476) and the bottom of the sliding hole (4711). The limiting rod (476) has a limiting hole (476) through its side wall. A curved groove (4761) is provided corresponding to the limiting ball (475), and the minimum vertical clearance between the bottom of the curved groove (4761) and the bearing of the hand crank shaft (471) is clearance-fitted with the limiting ball (475); a clearance groove (482) is provided on the side wall of the mounting hole (481) corresponding to the limiting ball (475) to allow the limiting ball (475) to completely disengage from the curved groove (4761); a limiting pin (48) is fixed in the sliding hole (4711), and so on. The limiting rod (476) has a limiting hole (4762) corresponding to the limiting pin (48) to limit the sliding range of the limiting rod (476). The end of the limiting rod (476) is always located in the sliding hole (4711). The end of the hand crank shaft (471) away from the first hand crank bevel gear (472) has a vertical groove (4715) that passes through the sliding hole (4711). The end of the limiting rod (476) is always located in the vertical groove (4715).

5. The electric mechanism for tap changer of UHV converter transformer according to claim 1, characterized in that, The gear position indicator and protection component (7) includes a linkage component (8) and a signal feedback component (9). The linkage component (8) is connected to one end of the output shaft (43) of the reduction component (4) for linkage and drives the mechanism in the signal feedback component (9) to provide feedback on the action signal. The linkage component (8) includes a linkage housing (81), a primary transmission shaft (82), a secondary worm (83), and a tertiary worm wheel (84). The primary transmission shaft (82) and the secondary worm (83) are rotatably installed in the linkage housing (81). The upper end of the primary transmission shaft (82) passes through the linkage housing (81) and is coaxially fixed with the output shaft (43) of the reduction component (4). A one-to-one gear pair is provided between the primary transmission shaft (82) and the secondary worm (83) for constant speed transmission. The secondary worm (83) meshes with the tertiary worm wheel (84) for transmission, and the transmission ratio is the same as the transmission ratio of the worm wheel box (11) on the top of the tap changer.

6. The electric mechanism for tap changer of UHV converter transformer according to claim 5, characterized in that, The linkage component (8) also includes a first driven shaft (85), which is rotatably mounted on the linkage housing (81), and a three-stage worm gear (84) is fixed on the first driven shaft (85); The signal feedback component (9) includes a functional housing (92) and an action signal feedback component (93). The action signal feedback component (93) includes a trigger wheel (851) coaxially fixed on a first driven shaft (85) and a first limit switch (853) disposed below the trigger wheel (851). The first limit switch (853) is fixed on the functional housing (92). Two clearance planes (852) are provided on the periphery of the trigger wheel (851), and the two clearance planes (852) are parallel to each other. The circumferential surface of the trigger wheel (851) will press the first limit switch (853). When the clearance plane (852) of the trigger wheel (851) is directly opposite the first limit switch (853), the pressing of the first limit switch (853) is released. Two pairs of clearance planes (852) are provided along the axial direction of the trigger wheel (851), and two first limit switches (853) are provided corresponding to the two pairs of clearance planes (852).

7. The electric mechanism for tap changer of ultra-high voltage converter transformer according to claim 5, characterized in that, The signal feedback component (9) includes a functional box (92) and a panel (91) installed on the side of the functional box (92) away from the linkage component (8). A gear position pointer (911) and a rotation position pointer (912) are rotatably mounted on the panel (91). Different gear positions are set on the panel (91) corresponding to the gear position pointer (911), and different circumferential position positions are set on the panel (91) corresponding to the rotation position pointer (912). The rotation axes of the gear position pointer (911) and the rotation position pointer (912) are coaxially arranged. The linkage component (8) also includes a second driven shaft (86), which is rotatably mounted on the linkage housing (81). A three-stage worm gear (84) is fixed on the second driven shaft (86). The second driven shaft (86) passes through the functional housing (92) and panel (91) of the signal feedback component (9). The rotation position pointer (912) is fixed at the end of the second driven shaft (86). A driven shaft is coaxially sleeved at one end of the second driven shaft (86) near the panel (91). A bushing (88) is provided, with the end of the driven bushing (88) fixed to the gear pointer (911) insert sleeve; a drive disc (867) is coaxially mounted on one end of the second driven shaft (86) near the driven bushing (88), with one end of the driven bushing (88) coaxially inserted and fixed to the drive disc (867), and the other end of the driven bushing (88) rotatably inserted into the panel (91); a gear reduction assembly (4) is provided between the drive disc (867) and the second driven shaft (86) for speed reduction transmission.

8. The electric mechanism for tap changer of ultra-high voltage converter transformer according to claim 7, characterized in that, The linkage component (8) also includes a third driven shaft (87), on which a swing block (871) is fixed. A lever (868) for actuating the swing block (871) is provided on the side of the drive disk (867) near the swing block (871). A counterweight (872) is fixed on the third driven shaft (87), which ensures that the swing block (871) is always on the rotation trajectory of the lever (868) when no external force is applied. The signal feedback component (9) also includes a first gear signal feedback component (94), which includes a straight trigger rod (873) fixed on the third driven shaft (87), two micro switches (874) disposed at both ends of the trigger rod (873), and two second limit switches (875) disposed at both ends of the trigger rod (873). The micro switches (874) and the second limit switches (875) are arranged along the axial direction of the third driven shaft (87), and the trigger rod (873) is provided with two corresponding micro switches (874) and second limit switches (875).

9. The electric mechanism for tap changer of ultra-high voltage converter transformer according to claim 7, characterized in that, The second gear signal feedback component (95) includes a signal disk (96) coaxially arranged with the driven bushing (88) and a trigger disk (97) coaxially fixed on the driven bushing (88); the signal disk (96) is coaxially arranged with a conductive ring and a circular array of contact points, the distribution of which corresponds to the center angle of the gear position on the panel (91); a contact bridge is fixed on the side of the trigger disk (97) near the signal disk (96), the contact bridge is a conductive metal plate, and elastic contact plates that slide and abut against the conductive ring and the contact points at both ends of the contact bridge.

10. A control method for the electric mechanism of a tap changer used in the above-mentioned ultra-high voltage converter transformer, characterized in that, Includes the following steps: S1, receive the gear adjustment command, start the motor (3) to rotate forward or reverse, drive the switch body drive shaft to rotate through the transmission component (5) to complete the gear adjustment, and update the gear indicator and the display of the protection component (7) through one-to-one corresponding signal contacts, BCD code or analog output. S2, Before starting the motor (3), check whether the surge protection device at the power input port is working properly; S3, during gear adjustment, monitor whether the mechanical return time of contactors K2 / K3 exceeds the set threshold; S4. After the adjustment is completed, monitor whether the return time of the holding contact in S12 meets the requirements.

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