Dry-type vacuum on-load tap-changer and transformer device

Abstract

This application discloses a dry-type vacuum on-load tap changer and transformer. The dry-type vacuum on-load tap changer includes a selection switch assembly, a polarity switching mechanism, a moving contact assembly, a linear transmission mechanism, and a switching assembly. The polarity switching mechanism is integrated within the plane of the selection switch assembly to change the polarity of the voltage regulating winding. The moving contact assembly is used to move within the plane. The linear transmission mechanism drives the moving contact assembly to slide linearly to pre-select a tap position or change the polarity of the voltage regulating winding. The switching assembly is used to disconnect and reconnect the moving contact assembly to the main winding before and after tap position pre-selection. This application features a planar layout design, resulting in a more compact structure and convenient external wiring. The linear transmission mechanism enables tap position and polarity pre-selection. The switching assembly limits short-circuit circulating current, achieves smooth transfer of vacuum arc extinguishing, and improves the safety and reliability of the switch.

Description

Technical Field

[0001] This application relates to the field of transformer equipment technology, specifically to a dry-type vacuum positive and negative voltage regulating on-load tap changer and transformer equipment. Background Technology

[0002] On-load tap changers with forward and reverse voltage regulation are core voltage regulating components of power transformers, playing a crucial role in high-voltage and large-capacity transformers. Their core principle involves switching the forward or reverse connection of the regulating winding and the main winding using a polarity selector. This expands the voltage regulation range with the same number of turns in the regulating winding, while reducing the number of taps and simplifying insulation design.

[0003] Currently, the most widely used type of on-load tap changer is the oil-immersed type with forward and reverse voltage regulation, which uses transformer oil as the insulation and arc-extinguishing medium. Although this design meets the voltage regulation requirements of transformers to a certain extent, it cannot be directly applied to dry-type transformers with extremely high safety requirements due to the risk of oil leakage and fire and environmental restrictions. In recent years, vacuum on-load tap changers have gradually developed as a new technology. They use vacuum arc-extinguishing tubes to replace the original transition contacts, so that the arc only occurs within the vacuum arc-extinguishing tube. For dry-type tap changers, using vacuum arc extinguishing not only avoids pollution problems but also reduces the impact of the external environment on the switch and reduces maintenance frequency.

[0004] However, traditional dry-type on-load tap changers often employ a step-by-step or bridging voltage regulation structure. Their selectors typically use a cylindrical layout, with stationary contacts distributed circumferentially and moving contacts switching via rotation. When integrating a polarity switching mechanism, this cylindrical structure, due to space constraints, makes it difficult to simultaneously achieve tap selection and polarity switching on the same movement path. This necessitates the addition of an independent polarity selector to realize forward and reverse voltage regulation functions, increasing the switch's size and structural complexity. Furthermore, the circumferential distribution of stationary contacts in the cylindrical structure is incompatible with the linear tap arrangement of the regulating windings in dry-type transformers, resulting in long external wiring distances and complex wiring. In addition, existing dry-type on-load tap changers typically use only two contact groups for direct switching, lacking an intermediate transition circuit with a transition resistor. This causes the voltage difference between adjacent tap positions to directly act on the switching contacts at the moment of tap switching, generating significant short-circuit circulating current and arc energy, affecting switching safety and contact lifespan.

[0005] Therefore, how to achieve forward and reverse voltage regulation in dry-type transformers while solving the problems of spatial layout and transition switching mechanism is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] In order to solve the technical problems in the prior art, this application provides a dry vacuum positive and negative voltage regulating on-load tap changer and transformer equipment.

[0007] The dry-type vacuum positive and negative voltage regulating on-load tap changer and transformer equipment provided in this application adopts the following technical solution: A dry-type vacuum on-load tap changer with forward and reverse voltage regulation includes: The selector switch assembly has fixed contact arrays arranged in the same plane and uses a linear selection method for gear pre-selection. A polarity switching mechanism, integrated in the plane of the selection switch assembly, is used to change the polarity of the transformer's regulating winding to achieve positive and negative voltage regulation. A movable contact assembly for moving within the plane of the selector switch assembly; A linear transmission mechanism is used to drive each moving contact of the moving contact assembly to slide linearly on the fixed contact array in order to preselect the gear position of the switch assembly and / or change the connection polarity of the voltage regulating winding. A switching assembly has one end for electrical connection to one end of another winding of the transformer, the other end of which is electrically connected to the A end of the main winding. The other end of the switching assembly is for connection or disconnection with the moving contact assembly. It is used to disconnect the electrical connection between the moving contact assembly and the other winding before the moving contact assembly is pre-selected, and to reconnect the moving contact assembly to the other winding after the moving contact assembly is pre-selected.

[0008] In some embodiments, the fixed contact array includes an odd column consisting of a plurality of odd fixed contacts distributed along a straight line, an even column consisting of a plurality of even fixed contacts distributed along a straight line, and a zero-position fixed contact; the polarity conversion mechanism includes a polarity column consisting of a first polarity plate K+ and a second polarity plate K- distributed along a straight line; the odd column, the even column, and the polarity column are arranged in parallel to each other.

[0009] In some embodiments, the linear transmission mechanism includes a slide that can be driven to move linearly by power, and the sliding direction of the slide is perpendicular to the odd column, the even column and the polar column; The movable contact assembly includes odd-numbered movable contacts, even-numbered movable contacts, and polarized movable contacts fixed on the slide. During the movement of the slide, the odd-numbered movable contacts can be connected to the corresponding odd-numbered fixed contacts, the even-numbered movable contacts can be connected to the corresponding even-numbered fixed contacts, and the polarized movable contacts can be connected to the first polarized contact K+ or the second polarized contact K-.

[0010] In some embodiments, the movable contact assembly further includes odd-numbered conductive rods, even-numbered conductive rods, and polarity conductive rods respectively disposed above the odd-numbered column, the even-numbered column, and the polarity column; One end of the odd-numbered moving contact piece is slidably disposed on the odd-numbered conductive rod and electrically connected to it, and the other end is sequentially connected to each odd-numbered fixed contact piece during the movement of the slide table. One end of the even-numbered moving contact piece is slidably disposed on the even-numbered conductive rod and electrically connected to it, and the other end is sequentially connected to each even-numbered fixed contact or the zero-position fixed contact during the movement of the slide table. One end of the polar moving contact is slidably disposed on and electrically connected to the polar conductive rod, and the other end is sequentially connected to the first polar piece K+ or the second polar piece K- during the movement of the slide table. The polar conductive rod is used to electrically connect to the K end of the main winding. The zero-position fixed contact is used to electrically connect to the K end of the main winding via a wire.

[0011] In some embodiments, the first polarity plate K+ and the second polarity plate K- in the polarity column are respectively formed by multiple polarity fixed contacts electrically connected by connecting pieces, or are respectively formed by a single flat strip-shaped fixed contact.

[0012] In some embodiments, the linear transmission mechanism further includes a housing, a first rotational drive member, a transmission gear set, a transmission shaft, two first bevel gears, two lead screws, two second bevel gears, two nuts, and a counter. The transmission shaft is rotatably disposed on the housing. The first rotational drive member is connected to the transmission shaft via the transmission gear set and is used to drive the transmission shaft to rotate. The two first bevel gears are respectively fixed to both ends of the transmission shaft. The two lead screws are respectively rotatably disposed on both sides of the housing. The two second bevel gears are respectively fixed to one end of the two lead screws. The two nuts are respectively threaded into the two lead screws. The two nuts are respectively fixed to both ends of the slide. The counter is electrically connected to the first rotational drive member and is used to obtain the rotation angle of the first rotational drive member to determine the position of the slide relative to the housing.

[0013] In some embodiments, the switching assembly includes a first vacuum interrupter, a second vacuum interrupter, a third vacuum interrupter, and a closing drive assembly. The first vacuum interrupter has a first moving conductive rod and a first fixed conductive rod. The second vacuum interrupter has a second moving conductive rod and a second fixed conductive rod. The third vacuum interrupter has a third moving conductive rod and a third fixed conductive rod. The first moving conductive rod, the second moving conductive rod, and the third moving conductive rod are all used to electrically connect to one end of other windings. The other end of the other windings is electrically connected to the A end of the main winding. The first fixed conductive rod is electrically connected to the odd-numbered conductive rods. The second fixed conductive rod is electrically connected to the even-numbered conductive rods via a resistor. The third fixed conductive rod is electrically connected to the even-numbered conductive rods. The closing drive assembly is used to drive the opening and closing of the first vacuum interrupter, the second vacuum interrupter, and the third vacuum interrupter according to the position of the slide table to achieve steady-state conduction and transition, specifically including: In the steady-state conduction state, only the first vacuum interrupter or the third vacuum interrupter is in the closed state; During the transition from odd-numbered to even-numbered gears, after the slide table drives the even-numbered moving contact to connect any even-numbered fixed contact, the closing drive assembly sequentially drives the second vacuum interrupter to close, the first vacuum interrupter to open, the third vacuum interrupter to close, and the second vacuum interrupter to open. During the transition from even-numbered to odd-numbered gears, after the slide table drives the odd-numbered moving contact to connect any odd-numbered fixed contact, the closing drive assembly sequentially drives the second vacuum interrupter to close, the third vacuum interrupter to open, the first vacuum interrupter to close, and the second vacuum interrupter to open.

[0014] In some embodiments, the closing drive assembly includes a drive shaft, a second rotation drive member, a first cam, a second cam, and a third cam; The second rotation drive component is connected to the drive shaft for driving the drive shaft to rotate; The first cam, the second cam, and the third cam are fixedly sleeved on the drive shaft at axial intervals and rotate synchronously with the drive shaft; The ends of the first moving conductive rod, the second moving conductive rod, and the third moving conductive rod that are away from their respective corresponding vacuum interrupters are respectively engaged with the outer contours of the first cam, the second cam, and the third cam in a transmission cooperation. The outer contour driving surfaces of the first cam, the second cam, and the third cam are offset from each other in the circumferential direction. When the drive shaft rotates to switch gears, the offset outer contour driving surfaces of the first cam, the second cam, and the third cam push the corresponding moving conductive rod to move. The circumferential angle of the offset outer contour protrusions of the first cam, the second cam, and the third cam is configured such that when the drive shaft rotates to the transition stage where the odd-numbered fixed contacts and the even-numbered fixed contacts alternate, the second moving conductive rod and the second fixed conductive rod in the second vacuum interrupter connected in series with a resistor close before the corresponding disconnection action, so as to limit the circulating current during switching.

[0015] This application also provides a transformer device, including: The transformer body includes a main winding, a voltage regulating winding, and other windings; and The aforementioned dry-type vacuum on-load tap changer with forward and reverse voltage regulation; The A end of the main winding is electrically connected to one end of the other winding, and the other end of the other winding is electrically connected to the switching assembly of the dry vacuum positive and negative voltage regulating on-load tap changer. The K-end of the main winding is electrically connected to the polarity conductive rod of the dry vacuum positive and negative voltage regulating on-load tap changer. Both ends of the voltage regulating winding are electrically connected to the polarity conversion mechanism, and each tap of the voltage regulating winding is electrically connected to the corresponding fixed contact in the fixed contact array of the preselection switch assembly of the dry vacuum positive and negative voltage regulating on-load tap changer.

[0016] In some embodiments, in the fixed contact array of the dry vacuum positive and negative voltage regulating on-load tap changer, two fixed contacts are provided for each corresponding to the same position. Two wires are led out from the same tap of the voltage regulating winding and electrically connected to two fixed contacts corresponding to the same gear position; or, the two fixed contacts corresponding to the same gear position are connected in parallel inside the dry-type vacuum positive and negative voltage regulating on-load tap changer, and a wire is led out from the same tap of the voltage regulating winding and electrically connected to one of the fixed contacts.

[0017] In summary, this application includes at least one of the following beneficial technical effects: 1. The dry-type vacuum forward and reverse voltage regulating on-load tap changer, through its planar layout design, differs from the traditional cylindrical structure. This allows the layout of the fixed contact array to match the linear tap arrangement of the dry-type transformer's regulating winding, shortening the external wiring distance. A linear drive mechanism enables the moving contact assembly to slide linearly across the fixed contact array, achieving pre-selection of the tap position and polarity switching. The switching assembly employs three independent vacuum arc-extinguishing tube structures, and through the staggered design of the cam group, it achieves a "connect first, disconnect later" mechanical timing sequence, effectively limiting short-circuit circulating current during switching and achieving smooth transfer of vacuum arc extinguishing. Simultaneously, the design of the zero-position fixed contact, combined with the planar polarity plate, enables graded adjustment of the output voltage in both forward and reverse directions without increasing the winding length. This design scheme combines vacuum arc extinguishing and forward and reverse voltage regulation in the dry-type transformer tap changer, improving the safety and reliability of the switch. 2. By combining a dry-type vacuum on-load tap changer with the transformer body, the transformer equipment utilizes the switch's forward and reverse voltage regulation function to expand the voltage regulation range with the same number of turns in the regulating winding, while reducing the number of taps and simplifying insulation design. Two different wiring methods can adapt to different operating conditions and assembly requirements, improving the equipment's flexibility and applicability. Through reasonable electrical connections, the main winding, regulating winding, other windings, and switch can work together to achieve reliable voltage regulation and stable output. This optimizes the structural layout of traditional transformer equipment in terms of voltage regulation and wiring, improving the overall performance and reliability of the transformer equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a transformer device provided in one embodiment of this application; Figure 2 yes Figure 1 A schematic diagram of the overall three-dimensional structure of a medium-dry type vacuum positive and negative voltage regulating on-load tap changer; Figure 3 yes Figure 1 A top view of the structure of a medium-dry vacuum on-load tap changer with forward and reverse voltage regulation; Figure 4 yes Figure 1 A partial structural schematic diagram of the fixed contact array, polarity conversion mechanism, and moving contact assembly; Figure 5 yes Figure 4 A partial structural diagram of the center contact array and polarity conversion mechanism; Figure 6 yes Figure 2 A magnified view of the structure at point B in the middle; Explanation of reference numerals in the attached drawings: 1. Dry-type vacuum positive and negative voltage regulating on-load tap changer; 11. Selector switch assembly; 111. Fixed contact array; 1111. Odd-numbered fixed contacts; 1112. Even-numbered fixed contacts; 1113. Zero-position fixed contact; 12. Polarity switching mechanism; 121. First polarity plate K+; 122. Second polarity plate K-; 123. Polarity fixed contact; 124. Connecting piece; 13. Moving contact assembly; 131. Odd-numbered moving contacts; 132. Even-numbered moving contacts; 133. Polarity moving contacts; 134. Odd-numbered conductive rods; 135. Even-numbered conductive rods; 136. Polarity conductive rods; 14. Linear transmission mechanism; 141. Housing; 142. First rotational drive component; 143. Transmission gear set; 144. Transmission shaft; 145. First bevel gear. 146. Lead screw; 147. Second bevel gear; 148. Nut; 149. Slide table; 15. Switching assembly; 151. First vacuum interrupter; 152. Second vacuum interrupter; 153. Third vacuum interrupter; 154. First moving conductive rod; 155. Second moving conductive rod; 156. Third moving conductive rod; 157. First fixed conductive rod; 158. Second fixed conductive rod; 159. Third fixed conductive rod; 1510. Resistor; 1511. Closure drive assembly; 15111. Drive shaft; 15112. Second rotation drive component; 15113. First cam; 15114. Second cam; 15115. Third cam; 2. Transformer equipment; 21. Transformer body; 211. Main winding; 212. Voltage regulating winding. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments are only possible technical implementations of the present invention, but are not limited thereto. Other embodiments obtained by those skilled in the art in conjunction with the embodiments of the present invention without creative effort are also within the protection scope of the present invention.

[0020] This application mainly adopts a planar layout to realize dry-type vacuum forward and reverse voltage regulation, which achieves the effect of providing a matching tap changer for dry-type transformers, realizing vacuum arc extinguishing switching and forward and reverse voltage regulation. The following is a further detailed description of this application.

[0021] Example 1 Please refer to Figures 1 to 3 The dry vacuum positive and negative voltage regulating on-load tap changer 1 provided in this application embodiment includes a selection switch assembly 11, a polarity conversion mechanism 12, a moving contact assembly 13, a linear transmission mechanism 14, and a switching switch assembly 15. In this configuration, the fixed contact array 111 of the selector switch assembly 11 is arranged in the same plane, the polarity conversion mechanism 12 is integrated in the same plane, the moving contact assembly 13 moves in the same plane, and the linear transmission mechanism 14 drives the moving contact assembly 13 to slide linearly on the fixed contact array 111 to pre-select a gear position, and / or change the polarity of the voltage regulating winding 212. One end of the switching switch assembly 15 is used to electrically connect to one end of another winding, and the other end of the other winding is electrically connected to the A end of the main winding 211. The other end of the switching switch assembly 15 is used to connect or disconnect with the moving contact assembly 13, to disconnect the moving contact assembly 13 from the other winding before the moving contact assembly 13 pre-selects a gear position, and to reconnect the moving contact assembly 13 to the other winding after the moving contact assembly 13 pre-selects a gear position. This layout and coordination make the layout of the fixed contact array match the linear tap arrangement of the voltage regulating winding of the dry transformer, shorten the external wiring distance, and also realize safe and reliable vacuum arc extinguishing switching and positive and negative voltage regulation functions.

[0022] Please refer to Figure 4 and Figure 5Specifically, the fixed contact array 111 of the selector switch assembly 11 includes an odd column composed of several odd-numbered fixed contacts 1111 arranged in a straight line, an even column composed of several even-numbered fixed contacts 1112 arranged in a straight line, and a zero-position fixed contact 1113. The polarity switching mechanism 12 includes a polarity column composed of a first polarity plate K+121 and a second polarity plate K-122 arranged in a straight line. The odd-numbered column, even-numbered column, and polarity column are arranged in parallel to each other. The odd-numbered fixed contacts 1111 and even-numbered fixed contacts 1112 are generally made of a metal material with good conductivity, such as copper alloy, and their shape can be block-shaped or sheet-shaped. In the polarity series, the first polarity plate K+121 and the second polarity plate K-122 can be constructed by electrically connecting multiple polarity stationary contacts 123 via connecting pieces 124 to ensure conductive area and contact stability. The connecting pieces 124 are also made of materials with good conductivity. Alternatively, in actual manufacturing, a single flat, elongated stationary contact can be integrally molded. Using multiple polarity stationary contacts electrically connected via connecting pieces allows for flexible adjustment of the length of the polarity plates and the contact position according to different gear ratios. Using a single flat, elongated stationary contact integrally molded reduces the number of connection points, lowers contact resistance, and improves conductive reliability.

[0023] During operation, the linear parallel layout of the fixed contact array 111, combined with the directional movement of the slide table 149, achieves a compact spatial distribution, enabling the taps of the dry-type transformer to be connected to the same plane in a shorter distance and more intuitive mapping manner, shortening the lead distance, optimizing the insulation design space, and simplifying the wiring structure.

[0024] Please refer to the reference. Figure 2 and Figure 3The linear transmission mechanism 14 drives the movable contact assembly 13 to move linearly in a plane. It includes a housing 141, a first rotary drive component 142, a transmission gear set 143, a transmission shaft 144, two first bevel gears 145, two lead screws 146, two second bevel gears 147, two nuts 148, and a counter. The housing 141 protects and supports the internal components and is generally made of sturdy metal, providing a certain level of protection. The first rotary drive component 142 is the power source; besides a drive motor, other devices capable of providing rotational power can also be used. The first rotary drive component 142 is connected to the transmission shaft 144 via the transmission gear set 143 and drives the transmission shaft 144 to rotate. The transmission gear set 143 includes at least one pair of meshing gears, used to reduce the output speed of the first rotational drive 142 and increase the torque before transmitting it to the transmission shaft 144. Two first bevel gears 145 are respectively fixed to both ends of the transmission shaft 144, two lead screws 146 are respectively rotatably disposed on both sides of the housing 141, and two second bevel gears 147 are respectively fixed to one end of the two lead screws 146. The first bevel gears 145 mesh with the corresponding second bevel gears 147, thereby driving the parallel lead screws 146 on both sides to rotate synchronously. Two nuts 148 are threaded into the two lead screws 146, and the two nuts 148 are respectively fixed to both ends of the slide table 149. When the lead screws 146 rotate, the nuts 148 will move linearly along the threads of the lead screws 146, thereby converting the rotational motion into the translational motion of the slide table 149. The counter is electrically connected to the first rotational drive 142, and by obtaining the rotation angle of the first rotational drive 142, the position of the slide table 149 relative to the housing 141 is determined. The sliding direction of the slide table 149 is perpendicular to the odd column, even column and polarity column. This design enables the moving contact assembly 13 to slide accurately in a straight line on the fixed contact array 111.

[0025] The linear transmission mechanism 14 operates as follows: the first rotary drive component 142 rotates, and power is smoothly transmitted to the transmission shaft 144 via the transmission gear set 143. The first bevel gears 145 at both ends of the transmission shaft 144 drive the second bevel gears 147 on both sides to rotate synchronously, thereby causing the lead screws 146 on both sides to rotate synchronously, driving the slide table 149 fixed on the nuts 148 at both ends to perform linear translation. In this embodiment, the symmetrical mechanical transmission design of double lead screws and double bevel gears improves the stability and anti-skewness capability of the slide table 149 when carrying multiple moving contact pieces for long-distance linear movement; at the same time, the introduction of the counter replaces the traditional limit switch, improving the positioning accuracy of gear pre-selection.

[0026] The movable contact assembly 13 includes an odd number of movable contacts 131, an even number of movable contacts 132, and a polarity movable contact 133 fixed on the slide table 149, as well as an odd number of conductive rods 134, an even number of conductive rods 135, and a polarity conductive rod 136 respectively disposed above the odd column, the even column, and the polarity column. Specifically, the odd-numbered conductive rods 134 extend parallel to the odd-numbered columns, are positioned above the odd-numbered fixed contacts 1111 and maintain a preset distance from the plane containing the odd-numbered fixed contacts 1111, and are fixed to the housing 141 by an insulating bracket. The even-numbered conductive rods 135 extend parallel to the even-numbered columns, are positioned above the even-numbered fixed contacts 1112 and maintain a preset distance from the plane containing the even-numbered fixed contacts 1112, and are fixed to the housing 141 by an insulating bracket. The polarized conductive rods 136 extend parallel to the polarized columns, are positioned above the first polarized piece K+121 and the second polarized piece K-122 and maintain a preset distance from the plane containing the first polarized piece K+121 and the second polarized piece K-122, and are fixed to the housing 141 by an insulating bracket. One end of the odd-numbered movable contact 131 is slidably disposed on and electrically connected to the odd-numbered conductive rods 134, and the other end sequentially connects to each of the odd-numbered fixed contacts 1111 during the movement of the slide table 149. Odd-numbered moving contacts 131 are typically made of a conductive material with good elasticity, such as beryllium bronze, to ensure good contact with odd-numbered fixed contacts 1111. One end of the even-numbered moving contacts 132 is slidably mounted on and electrically connected to the even-numbered conductive rod 135, while the other end sequentially connects to each even-numbered fixed contact 1112 or the zero-position fixed contact 1113 during the movement of the slide table 149. One end of the polarity moving contact 133 is slidably mounted on and electrically connected to the polarity conductive rod 136, while the other end sequentially connects to the first polarity piece K+121 or the second polarity piece K-122 during the movement of the slide table 149. The polarity conductive rod 136 and the zero-position fixed contact 1113 are both designed to be electrically connected to the K end of the main winding 211 via a wire. The cooperation of these moving contacts and conductive rods allows current to be smoothly conducted between different positions and polarities.

[0027] It should be noted that the polarity conversion mechanism 12 not only includes the statically arranged first polarity plate K+121 and second polarity plate K-122, but also, in actual working condition, it slides and cooperates with the polarity moving contact plate 133 in the moving contact plate assembly 13 to jointly complete the change of the polarity of the voltage regulating winding 212.

[0028] During operation, the slide table 149 moves, causing each moving contact to slide synchronously. One end of the moving contact slides continuously over a long distance on the suspended conductive rod to draw power, while the other end precisely switches and connects to the various fixed contacts or polarity plates below. In this embodiment, the sliding electrical connection between the fixed conductive rod and the moving contact replaces the flexible wire that is dragged back and forth with the moving parts in traditional on-load tap changers. This avoids the risk of metal fatigue fracture caused by frequent bending and movement of the flexible wire, thus improving the service life of the dry-type switch and the reliability of system operation.

[0029] Please refer to Figure 2 and Figure 6 The switching assembly 15 is responsible for cutting off and conducting the main current during gear switching to realize vacuum arc extinguishing transfer. It includes a first vacuum arc extinguishing tube 151, a second vacuum arc extinguishing tube 152, a third vacuum arc extinguishing tube 153, and a set of closing drive assembly 1511. Among them, the first vacuum arc extinguishing tube 151 has a first moving conductive rod 154 and a first fixed conductive rod 157, the second vacuum arc extinguishing tube 152 has a second moving conductive rod 155 and a second fixed conductive rod 158, and the third vacuum arc extinguishing tube 153 has a third moving conductive rod 156 and a third fixed conductive rod 159. The first moving conductive rod 154, the second moving conductive rod 155, and the third moving conductive rod 156 are all used for electrical connection to one end of other windings, the other end of which is electrically connected to end A of the main winding 211; the first fixed conductive rod 157 is electrically connected to the odd-numbered conductive rod 134; the second fixed conductive rod 158 is electrically connected to the even-numbered conductive rod 135 via a resistor 1510; the resistance value of the resistor 1510 is selected according to the rated current of the transformer and the inter-stage voltage difference, generally selected to ensure that the transient circulating current does not exceed a certain proportion (such as 1.5 times) of the rated current. The third fixed conductive rod 159 is electrically connected to the even-numbered conductive rod 135. In this embodiment, each vacuum interrupter tube has a pair of separable contacts inside. The end of the moving conductive rod is provided with a moving contact terminal, and the end of the fixed conductive rod is provided with a stationary contact terminal. When the moving conductive rod moves towards the fixed conductive rod under the drive of the cam, the moving contact terminal and the stationary contact terminal make contact and conduct. When the moving conductive rod moves in the opposite direction, the moving contact terminal and the stationary contact terminal separate, and the generated arc is quickly extinguished in the vacuum environment. Preferably, each moving conductive rod has a roller at the end away from the vacuum interrupter tube. The roller abuts against the outer contour surface of the corresponding cam. Each moving conductive rod is also fitted with a return spring. When the convex section of the cam rotates, the return spring drives the moving conductive rod to retract, so that the moving contact terminal and the stationary contact terminal inside the vacuum interrupter tube are separated.

[0030] The closed drive assembly 1511 includes a drive shaft 15111, a second rotation drive member 15112, and a first cam 15113, a second cam 15114, and a third cam 15115 that are axially spaced and fixedly sleeved on the drive shaft 15111. The outer contour drive surfaces of the three cams are offset from each other in the circumferential direction. The ends of the first moving conductive rod 154, the second moving conductive rod 155, and the third moving conductive rod 156 away from their respective corresponding vacuum interrupters are respectively engaged with the outer contours of the three cams. When it is necessary to switch gears, the second rotation drive member 15112 drives the drive shaft 15111 to rotate, and the three cams, by virtue of their offset outer contour drive surfaces, push the corresponding moving conductive rods to move according to a preset timing sequence. For example, during the transition phase where odd-numbered fixed contacts 1111 and even-numbered fixed contacts 1112 alternate, the protrusion of the second cam 15114 actuates first, causing the second moving conductive rod 155 and the second fixed conductive rod 158 within the second vacuum interrupter 152 (with resistor 1510 connected in series) to close before the corresponding disconnection action, thereby limiting the circulating current during switching. In this embodiment, to achieve a transition sequence of connection before disconnection, the outer contours of all three cams are provided with a reference circular segment and a protrusion segment. In terms of physical geometric phase, the protrusion segment of the second cam 15114 (corresponding to the transition state) spans between the protrusion segment of the first cam 15113 and the protrusion segment of the third cam 15115, and each has a specific overlapping phase angle. Preferably, the value of the overlapping phase angle ranges from 3° to 20°. The numerical range design of the overlapping phase angle ensures that, on the one hand, the vacuum arc-extinguishing tubes can still reliably achieve "connection before disconnection" even under the conditions of machining tolerances and long-term wear, avoiding the instantaneous disconnection of the main circuit that could cause arcing or overvoltage; on the other hand, it also strictly limits the connection time of the transition resistor 1510 during the transition process, preventing the transition resistor 1510 from overheating and being damaged due to prolonged current flow.

[0031] Its working process and technical effects are as follows: Utilizing three staggered cams on the same drive shaft 15111, the rotational motion is directly converted into the linear opening and closing motion of the three vacuum arc-extinguishing tube moving conductive rods. This purely mechanical hard interlocking design reduces the risk of electrical misoperation caused by control system failures (such as short circuits caused by simultaneous unobstructed direct connection of two gears); the second vacuum arc-extinguishing tube 152 of the series resistor 1510 absorbs and limits the circulating current at the moment of switching, realizing vacuum arc extinguishing and smooth gear switching under load, enabling the transformer to safely regulate voltage without interrupting power.

[0032] Regarding system turn-on and switching, the specific timing of the closed-loop drive component 1511 is as follows: When the system is in an odd-number steady state, only the first vacuum interrupter 151 is closed. When the system transitions from an odd-numbered to an even-numbered position, the slide 149 first moves to connect the even-numbered moving contact 132 to the target even-numbered fixed contact 1112. Then, the drive shaft 15111 rotates, and due to phase overlap, the raised section of the second cam 15114 drives the second vacuum interrupter 152 to close first. At this time, the main current is divided into two paths: one flows through the first vacuum interrupter 151 to the odd-numbered position, and the other flows through the resistor 1510 to the even-numbered position, with the resistor limiting the interstage circulating current. Next, the raised section of the first cam 15113 ends, the first vacuum interrupter 151 opens, and the main current is entirely borne by the second vacuum interrupter 152 with its resistor. Subsequently, the raised section of the third cam 15115 drives the third vacuum interrupter 153 to close, and finally the second vacuum interrupter 152 opens, completing the smooth transition to the even-numbered position.

[0033] Conversely, when the system transitions from an even-numbered range to an odd-numbered range (initially only the third vacuum interrupter 153 is closed), the slide 149 moves first to connect the odd-numbered moving contact 131 to the target odd-numbered fixed contact 1111. The drive shaft 15111 rotates in the opposite direction or continues to rotate (depending on the circumferential double-sided symmetrical design of the cam), and the raised section of the second cam 15114 again drives the second vacuum interrupter 152 to close first. At this time, since the second vacuum interrupter and the third vacuum interrupter 153 are connected in parallel on the even-numbered conductive rod 135, there is a stepless circulating current. Subsequently, the third vacuum interrupter 153 is disconnected, and the main current is transferred to the second vacuum interrupter 152 with a resistor. Immediately afterwards, the first cam 15113 drives the first vacuum interrupter 151 to close, and the main current is shunt through the first vacuum interrupter 151 and the second vacuum interrupter 152. The resistor 1510 also plays the role of limiting the short-circuit circulating current between the odd and even ranges. Finally, the second vacuum interrupter 152 disconnects, completing the smooth reverse transfer to the odd-numbered range.

[0034] Zero position operation: When the slide table 149 moves to the zero position, the even-numbered moving contact 132 connects to the zero-position fixed contact 1113, and the polarity moving contact 133 is in the empty space between the first polarity contact K+121 and the second polarity contact K-122. At this time, the voltage regulating winding 212 is bypassed, and the main winding 211 directly forms a circuit through the zero-position fixed contact 1113 and the polarity conductive rod 136.

[0035] The complete polarity conversion process (taking switching from positive polarity to reverse polarity as an example): When it is necessary to change the connection polarity of the voltage regulating winding 212, the linear transmission mechanism 14 drives the slide table 149 to move towards the zero position. First, through the timing action of the switching assembly 15, the main current is smoothly transferred to the even-numbered conductive rod 135 where the even-numbered moving contact 132 is located. Subsequently, the slide table 149 continues to move, causing the even-numbered moving contact 132 to connect the zero-position fixed contact 1113, and the system enters the aforementioned zero-position working state. While maintaining the main current passing through the zero-position fixed contact 1113, the slide table 149 continues to translate, and the polarity moving contact 133 slides out from the first polarity piece K+121, passes through the gap between the two, and slides to contact the second polarity piece K-122. Since the voltage regulating winding 212 has been bypassed and no current flows through it at this time, the sliding switching of the polarity moving contact 133 in this gap interval is a completely no-load switching and will not generate an arc. After the polarity switch is completed, the slide 149 continues to move, causing the odd-numbered moving contact 131 to connect the first odd-numbered fixed contact 1111 of the reverse voltage regulation. Finally, the switching assembly 15 operates again according to the timing sequence, smoothly transferring the main current to the odd-numbered conductive rod 134, thus completing the complete conversion from positive polarity to reverse polarity. The process of switching from reverse to positive polarity is similar.

[0036] In practical operation, the dry-type vacuum on-load tap changer 1 of this embodiment, through its planar layout design, differs from the traditional cylindrical structure, allowing the layout of the fixed contact array to match the linear tap arrangement of the regulating winding of the dry-type transformer, thus shortening the external wiring distance. The linear transmission mechanism 14 can drive the moving contact assembly 13 to slide linearly on the fixed contact array 111, realizing the pre-selection of the tap position and the conversion of polarity. The switching assembly 15 adopts three independent vacuum arc-extinguishing tube structures, and through the staggered design of the cam group, it realizes the "connect first, disconnect later" mechanical timing, effectively limiting the short-circuit circulating current during switching and achieving smooth transfer of vacuum arc extinguishing. At the same time, the design of the zero-position fixed contact 1113, combined with the planar polarity plate, realizes the graded adjustment of the output voltage in both directions without increasing the winding length. This design solves the problem of the lack of matching forward and reverse voltage regulating vacuum tap changers for dry-type transformers in the prior art, improving the safety and reliability of the switch.

[0037] Example 2 Please refer to Figure 1 The transformer device 2 provided in this application embodiment includes a transformer body 21 and the aforementioned dry-type vacuum positive and negative voltage regulating on-load tap changer 1. The transformer body 21 includes a main winding 211, a voltage regulating winding 212, and other windings.

[0038] In terms of electrical connections, the A end of the main winding 211 is electrically connected to one end of the other windings, and the other end of the other windings is electrically connected to the switching assembly 15 of the dry-type vacuum on-load tap changer 1. The K end of the main winding 211 is electrically connected to the polarity conductive rod 136 of the dry-type vacuum on-load tap changer 1. The two ends of the voltage regulating winding 212 are electrically connected to the polarity conversion mechanism 12, and each tap of the voltage regulating winding 212 is electrically connected to the corresponding fixed contact in the fixed contact array 111 of the preselection switch assembly 11 of the dry-type vacuum on-load tap changer 1.

[0039] In the fixed contact array 111 of the dry-type vacuum on-load tap changer 1, two fixed contacts are provided for each tap position. There are two ways to connect the same tap of the regulating winding 212 to the two fixed contacts corresponding to the same tap position. Method one is to connect two wires from the same tap of the regulating winding 212 to the two fixed contacts corresponding to the same tap position, respectively. This method is suitable for applications requiring high circuit independence and can better avoid interference. Method two is to connect the two fixed contacts corresponding to the same tap position in parallel inside the dry-type vacuum on-load tap changer 1, and then connect a wire from the same tap of the regulating winding 212 to one of the fixed contacts. This method simplifies the external wiring of the transformer, reducing wiring difficulty and cost.

[0040] In actual assembly and operation, the above connection methods can be flexibly selected according to different site spaces and wiring requirements. The technical effects are as follows: Method 1 retains a completely independent dual redundant return line, which has a stronger current carrying capacity and higher reliability after single-line failure; Method 2, by pre-parallelizing internally before the switch leaves the factory, directly halves the number of tap cables led out from the transformer body 21, reducing the amount of external wiring and fixing work during the manufacturing of large transformers, improving the overall assembly efficiency, and also reducing the risk of insulation breakdown caused by too many high-voltage flying wires or too close distances.

[0041] When the dry-type vacuum on-load tap changer 1 adopts the aforementioned detailed structure, the K end of the main winding 211 is electrically connected to the polarity conductive rod 136 and the zero-position fixed contact 1113 of the dry-type vacuum on-load tap changer 1, respectively. The A end of the main winding 211 is electrically connected to one end of other windings, and the other end of other windings is electrically connected to the first moving conductive rod 154, the second moving conductive rod 155 and the third moving conductive rod 156 of the switching switch assembly 15. The two ends of the voltage regulating winding 212 are electrically connected to the first polarity plate K+121 and the second polarity plate K-122 of the dry-type vacuum on-load tap changer 1, respectively. Each tap of the voltage regulating winding 212 is electrically connected to each odd-numbered fixed contact 1111 and each even-numbered fixed contact 1112 of the dry-type vacuum on-load tap changer 1.

[0042] In practical applications, this transformer device 2 combines a dry-type vacuum on-load tap changer 1 with the transformer body 21. Utilizing the switch's forward and reverse voltage regulation function, it can expand the voltage regulation range with the same number of turns in the regulating winding, while reducing the number of taps and simplifying insulation design. Two different wiring methods can adapt to different operating conditions and assembly requirements, improving the equipment's flexibility and applicability. Through reasonable electrical connections, the main winding 211, the regulating winding 212, other windings, and the switch can work together to achieve reliable voltage regulation and stable output.

[0043] 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. A dry-type vacuum forward and reverse voltage regulating on-load tap changer, characterized in that, include: Select switch assembly (11), wherein the fixed contact array (111) of the select switch assembly (11) is arranged in the same plane and the gear position is pre-selected by linear selection method; The polarity switching mechanism (12) is integrated in the plane of the selection switch assembly (11) and is used to change the connection polarity of the voltage regulating winding (212) of the transformer to achieve positive and negative voltage regulation. The movable contact assembly (13) is movable within the plane of the selection switch assembly (11); A linear transmission mechanism (14) is used to drive each of the moving contacts of the moving contact assembly (13) to slide linearly on the fixed contact array (111) to preselect the gear position of the switch assembly (11) and / or change the connection polarity of the voltage regulating winding (212). A switching assembly (15) has one end for electrical connection to one end of another winding of the transformer, and the other end for connection or disconnection to the moving contact assembly (13). It is used to disconnect the electrical connection between the moving contact assembly (13) and the other winding before the moving contact assembly (13) is pre-selected, and to reconnect the moving contact assembly (13) and the other winding after the moving contact assembly (13) is pre-selected. The other end of the other winding is electrically connected to the A end of the main winding (211) of the transformer.

2. The dry-type vacuum on-load tap changer with forward and reverse voltage regulation according to claim 1, characterized in that, The fixed contact array (111) includes an odd column consisting of a number of odd fixed contacts (1111) arranged in a straight line, an even column consisting of a number of even fixed contacts (1112) arranged in a straight line, and a zero fixed contact (1113). The polarity conversion mechanism (12) includes a polarity column consisting of a first polarity plate K+ (121) and a second polarity plate K- (122) arranged in a straight line. The odd column, the even column, and the polarity column are arranged in parallel to each other.

3. The dry-type vacuum on-load tap changer with forward and reverse voltage regulation according to claim 2, characterized in that, The linear transmission mechanism (14) includes a slide (149) that can move linearly by power drive, and the sliding direction of the slide (149) is perpendicular to the odd column, the even column and the polar column; The movable contact assembly (13) includes an odd number of movable contacts (131), an even number of movable contacts (132), and a polarity movable contact (133) fixed on the slide (149). During the movement of the slide (149), the odd number of movable contacts (131) can be connected to the corresponding odd number of fixed contacts (1111), the even number of movable contacts (132) can be connected to the corresponding even number of fixed contacts (1112), and the polarity movable contact (133) can be connected to the first polarity contact K+ (121) or the second polarity contact K- (122).

4. The dry-type vacuum on-load tap changer with forward and reverse voltage regulation according to claim 3, characterized in that, The moving contact assembly (13) further includes odd-numbered conductive rods (134), even-numbered conductive rods (135), and polar conductive rods (136) respectively disposed above the odd-numbered column, the even-numbered column, and the polarity column; One end of the odd-numbered moving contact (131) is slidably disposed on the odd-numbered conductive rod (134) and electrically connected thereto, while the other end sequentially connects each odd-numbered fixed contact (1111) during the movement of the slide table (149); One end of the even-numbered moving contact (132) is slidably disposed on the even-numbered conductive rod (135) and electrically connected thereto, while the other end is sequentially connected to each even-numbered fixed contact (1112) or the zero-position fixed contact (1113) during the movement of the slide table (149). One end of the polar moving contact (133) is slidably disposed on the polar conductive rod (136) and electrically connected thereto, and the other end is sequentially connected to the first polar piece K+ (121) or the second polar piece K- (122) during the movement of the slide table (149). The polar conductive rod (136) is used to electrically connect to the K end of the main winding (211). The zero-position fixed contact (1113) is used to electrically connect to the K end of the main winding (211) via a wire.

5. The dry-type vacuum forward and reverse voltage regulating on-load tap changer according to claim 2, characterized in that, The first polarity plate K+ (121) and the second polarity plate K- (122) in the polarity column are respectively composed of multiple polarity fixed contacts (123) electrically connected by connecting pieces (124), or are respectively composed of a single flat strip-shaped fixed contact.

6. The dry-type vacuum on-load tap changer with forward and reverse voltage regulation according to claim 3, characterized in that, The linear transmission mechanism (14) further includes a housing (141), a first rotation drive member (142), a transmission gear set (143), a transmission shaft (144), two first bevel gears (145), two lead screws (146), two second bevel gears (147), two nuts (148), and a counter; the transmission shaft (144) is rotatably mounted on the housing (141), the first rotation drive member (142) is connected to the transmission shaft (144) via the transmission gear set (143) and is used to drive the transmission shaft (144) to rotate, and the two first bevel gears (145) are respectively fixed to the housing (141). At both ends of the drive shaft (144), two lead screws (146) are rotatably mounted on both sides of the housing (141). Two second bevel gears (147) are fixed to one end of the two lead screws (146). Two nuts (148) are threadedly fitted to the two lead screws (146) and fixed to both ends of the slide (149). The counter is electrically connected to the first rotation drive (142) and is used to obtain the rotation angle of the first rotation drive (142) to determine the position of the slide (149) relative to the housing (141).

7. The dry-type vacuum on-load tap changer with forward and reverse voltage regulation according to claim 4, characterized in that, The switching assembly (15) includes a first vacuum interrupter (151), a second vacuum interrupter (152), a third vacuum interrupter (153), and a closing drive assembly (1511). The first vacuum interrupter (151) has a first moving conductive rod (154) and a first fixed conductive rod (157). The second vacuum interrupter (152) has a second moving conductive rod (155) and a second fixed conductive rod (158). The third vacuum interrupter (153) has a third moving conductive rod (156). The first moving conductor (154), the second moving conductor (155) and the third moving conductor (156) are all used to be electrically connected to one end of the main winding (211). The first fixed conductor (157) is electrically connected to the odd-numbered conductor (134). The second fixed conductor (158) is electrically connected to the even-numbered conductor (135) via a resistor (1510). The third fixed conductor (159) is electrically connected to the even-numbered conductor (135). The closing drive assembly (1511) is used to drive the opening and closing of the first vacuum interrupter (151), the second vacuum interrupter (152), and the third vacuum interrupter (153) according to the position of the slide (149) to achieve steady-state conduction and transition, specifically including: In the steady-state conduction state, only the first vacuum interrupter (151) or the third vacuum interrupter (153) is in the closed state. During the transition from odd to even gears, after the slide (149) drives the even-numbered moving contact (132) to connect any even-numbered fixed contact (1112), the closing drive assembly (1511) sequentially drives the second vacuum interrupter (152) to close, the first vacuum interrupter (151) to open, the third vacuum interrupter (153) to close, and the second vacuum interrupter (152) to open. During the transition from even-numbered to odd-numbered gears, after the slide (149) drives the odd-numbered moving contact (131) to connect any odd-numbered fixed contact (1111), the closing drive assembly (1511) sequentially drives the second vacuum interrupter (152) to close, the third vacuum interrupter (153) to open, the first vacuum interrupter (151) to close, and the second vacuum interrupter (152) to open.

8. The dry-type vacuum on-load tap changer with forward and reverse voltage regulation according to claim 7, characterized in that, The closed drive assembly (1511) includes a drive shaft (15111), a second rotation drive element (15112), a first cam (15113), a second cam (15114), and a third cam (15115); The second rotation drive (15112) is connected to the drive shaft (15111) for driving the drive shaft (15111) to rotate; The first cam (15113), the second cam (15114) and the third cam (15115) are fixedly sleeved on the drive shaft (15111) at axial intervals and rotate synchronously with the drive shaft (15111); The first moving conductive rod (154), the second moving conductive rod (155) and the third moving conductive rod (156) are respectively engaged with the outer contours of the first cam (15113), the second cam (15114) and the third cam (15115) at the ends away from their respective corresponding vacuum interrupters. The outer contour driving surfaces of the first cam (15113), the second cam (15114), and the third cam (15115) are offset from each other in the circumferential direction; when the drive shaft (15111) rotates to perform gear switching, the offset outer contour driving surfaces of the first cam (15113), the second cam (15114), and the third cam (15115) push the corresponding moving conductive rod to move; the first cam (15113), the second cam (15114), and the third cam (15115) are offset from each other in the circumferential direction. The outer contour protrusions of the third cam (15114) and the third cam (15115) are angularly arranged in the circumferential direction such that when the drive shaft (15111) rotates to the transition stage where the odd-numbered fixed contacts (1111) and the even-numbered fixed contacts (1112) alternately switch, the second moving conductive rod (155) and the second fixed conductive rod (158) in the second vacuum interrupter (152) connected in series with the resistor (1510) close before the corresponding disconnection action, so as to limit the circulating current during switching.

9. A transformer device, characterized in that, include: The transformer body (21) includes a main winding (211), a voltage regulating winding (212), and other windings. And the dry vacuum positive and negative voltage regulating on-load tap changer (1) as described in claim 4; The A end of the main winding (211) is electrically connected to one end of the other winding, and the other end of the other winding is electrically connected to the switching assembly (15) of the dry vacuum positive and negative voltage regulating on-load tap changer (1). The K end of the main winding (211) is electrically connected to the polarity conductive rod (136) of the dry vacuum positive and negative voltage regulating on-load tap changer (1). Both ends of the voltage regulating winding (212) are electrically connected to the polarity conversion mechanism (12), and each tap of the voltage regulating winding (212) is electrically connected to the corresponding fixed contact in the fixed contact array (111) of the selection switch assembly (11) of the dry vacuum positive and negative voltage regulating on-load tap changer (1).

10. The transformer equipment according to claim 9, characterized in that, In the fixed contact array (111) of the dry vacuum positive and negative voltage regulating on-load tap changer (1), there are two fixed contacts corresponding to the same gear position. Two wires are led out from the same tap of the voltage regulating winding (212) and electrically connected to two fixed contacts corresponding to the same gear position respectively; or, the two fixed contacts corresponding to the same gear position are connected in parallel inside the dry vacuum positive and negative voltage regulating on-load tap changer (1), and a wire is led out from the same tap of the voltage regulating winding (212) and electrically connected to one of the fixed contacts.

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