A switching mechanism for a load regulation switch and a switching method thereof

Abstract

This invention discloses a switching mechanism and method for an on-load tap changer, characterized by comprising a fixed base, a main fixed plate, a vacuum tube, a spring pull rod assembly, a cam drive assembly, and a switching contact assembly. The switching contact assembly consists of an elastic contact, a horn-shaped switching contact, and a flexible connecting wire. The spring pull rod has a built-in spring and a movable pull stud, with a roller at its top. The cam drive assembly consists of a main cam and a secondary cam driving the spring pull rod roller, and a switching cam driving the switching contact. The vacuum tube is mounted above the fixed base, the main fixed plate is mounted above the fixed base, the switching contact assembly is mounted on the main fixed plate, the spring pull rod assembly is connected to the moving contact of the vacuum tube, and the cam drive assembly synchronously pulls the spring pull rod assembly and the switching contact assembly. The switching contact action is triggered by a delayed method. This invention interlocks the switching action and uses a delayed triggering method, solving the problem of insufficient arc extinguishing time and contact damage in the prior art.

Description

Technical Field

[0001] This invention relates to a switching mechanism and switching method for an on-load tap changer. Background Technology

[0002] The working principle of an on-load tap changer is to draw several taps from the transformer windings. Through the on-load tap changer, the circuit can switch from one tap to another without interrupting the load current, thereby changing the effective number of turns in the windings, i.e., altering the transformer's transformation ratio. To ensure that the current is not interrupted during switching, current technology generally employs a transition circuit, i.e., a secondary circuit. The secondary circuit is first connected, then the main circuit is disconnected. During the operation of the secondary circuit, the switching contacts rapidly switch to another tap, then connect the main circuit again, and finally disconnect the secondary circuit. When this type of on-load tap changer disconnects the main circuit, an arc is generated at the break point. This arc is typically extinguished by introducing a vacuum interrupter. After arc extinguishing, the downstream switching contact group performs an arc-free switching.

[0003] The arc extinguishing time of a vacuum interrupter typically requires half a cycle, or 10 milliseconds. This means that in this type of on-load tap changer, after the vacuum interrupter in the main circuit breaks, it is necessary to wait for the arc extinguishing to complete before the switching contact assembly can switch. Existing on-load tap changers with this type of switching mechanism are all symmetrical structures. The action of switching from one tap to another and then back must be consistent. That is, the front-end structure has reserved space gaps, and the rear-end structure also has reserved space gaps to maintain consistent switching actions. This results in a longer switching process time, increased energy required for the drive mechanism, and a corresponding increase in size. Moreover, when the switching time is prolonged, it is easy to cause intermediate jamming. In order to solve the problem of intermediate jamming, the power of the drive mechanism is increased, and the total switching time is shortened, resulting in insufficient arc extinguishing time and damage to the contacts. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a switching mechanism and switching method for on-load tap changers, which interlocks the switching action and uses a delayed triggering method, thereby solving the problem of insufficient arc extinguishing time and damage to contacts in the prior art, shortening the total switching time and reducing the power required for the drive mechanism.

[0005] To solve the above-mentioned technical problems, the present invention provides a switching mechanism and switching method for an on-load tap changer, characterized in that it includes a fixed base, a main fixed plate, a vacuum tube, a spring pull rod assembly, a cam drive assembly, and a switching contact assembly; the switching contact assembly consists of an elastic contact, a horn-shaped switching contact, and a flexible connecting wire; the spring pull rod has a built-in spring and a movable pull pin, and a roller is provided at the top; the cam drive assembly consists of a main cam and a secondary cam that drive the roller of the spring pull rod, and a switching cam that drives the switching contact; the vacuum tube is installed above the fixed base, the main fixed plate is installed above the fixed base, the switching contact assembly is installed on the main fixed plate, the spring pull rod assembly is connected to the moving contact of the vacuum tube, and the cam drive assembly synchronously pulls the spring pull rod assembly and the switching contact assembly to move; the driving of the switching contact is triggered by a delayed method.

[0006] Preferably, the switching mechanism and switching method for an on-load tap changer are characterized by comprising a fixed base, a main fixed plate, a vacuum tube, a spring rod assembly, a cam drive assembly, and a switching contact assembly.

[0007] Preferably, the switching mechanism and switching method for an on-load tap changer are characterized in that the switching contact assembly consists of an elastic contact, a horn-shaped switching contact, and a flexible connecting wire.

[0008] Preferably, the switching mechanism and switching method for an on-load tap changer are characterized in that the spring rod has a built-in spring and a movable pull pin, and a roller is provided at the top.

[0009] Preferably, the switching mechanism and switching method for an on-load tap changer are characterized in that the cam drive assembly consists of a main cam and a secondary cam that drive the spring pull rod roller, and a switching cam that drives the switching contacts.

[0010] Preferably, the switching mechanism and switching method for an on-load tap changer are characterized in that a vacuum tube is installed above the fixed base, a main fixing plate is installed above the fixed base, a switching contact assembly is installed on the main fixing plate, a spring pull rod assembly is connected to the moving contact of the vacuum tube, and a cam drive assembly synchronously pulls the spring pull rod assembly and the switching contact assembly to move.

[0011] Preferably, the switching mechanism and switching method for an on-load tap changer are characterized in that the driving switching contact is triggered in a delayed manner.

[0012] Preferably, the main fixing plate is characterized in that a positioning groove is provided in the middle of the main fixing plate to install the switching contact assembly, and a guide limiting hole is provided on each of the left and right sides to restrict the spring pull rod assembly to slide up and down within the guide limiting hole.

[0013] Preferably, the switching contact assembly is characterized in that it includes a switching contact base, with symmetrical slots on both sides and a positioning pin hole in the middle. The slots are used to install a spring-loaded movable contact piece, and the positioning pin hole is used to install a horn-shaped switching contact.

[0014] Preferably, the horn-shaped switching contact is characterized in that a movable pin hole is provided in the middle of the horn-shaped switching contact, and a flexible connecting wire is installed at the bottom. The other end of the flexible connecting wire is connected to one of the vacuum tube moving contacts to form a main circuit.

[0015] Preferably, the spring pull rod assembly is characterized by comprising a roller, a pull rod, a spring, a movable pull pin, and a sliding connecting sleeve. The roller is installed at the top of the pull rod, the pull rod is rigidly connected to the sliding connecting sleeve, the spring and the movable pull pin are installed inside the sliding connecting sleeve, and the movable pull pin passes through the sliding connecting sleeve and is rigidly connected to the moving contact of the vacuum tube.

[0016] Preferably, the movable pull pin passes through the sliding connecting sleeve and is rigidly connected to the moving contact of the vacuum tube. The characteristic is that when the pull rod moves upward, the sliding connecting sleeve drives the movable pull pin to pull the moving contact of the vacuum tube to move upward synchronously. When the pull rod moves downward, the sliding connecting sleeve moves downward synchronously, compressing the internal spring. The spring presses the movable pull pin and applies a spring force to the moving contact of the vacuum tube.

[0017] Preferably, the main cam is characterized in that a main drive groove is provided on the main cam, and the main groove has a symmetrical structure with a high center and low sides.

[0018] Preferably, the auxiliary cam is characterized in that a drive auxiliary slide groove is provided on the auxiliary cam, and the auxiliary slide groove has a symmetrical structure with a lower middle and higher sides.

[0019] Preferably, the switching cam is characterized in that a rolling bearing is provided on the switching cam, and the rolling bearing drives the horn-shaped contact of the switching contact assembly to swing.

[0020] Preferably, the cam drive assembly synchronously pulls the spring rod assembly and the switching contact assembly, characterized in that the main cam, auxiliary cam, and switching cam of the cam drive assembly rotate synchronously; initial state position 0: the main cam presses down on the spring rod, the auxiliary cam pulls up the spring rod, and the switching cam presses down on one side of the horn-shaped contact; position 1: the main cam and auxiliary cam simultaneously press down on the spring rod, and the switching cam starts to rotate to the empty position; position 2: the main cam pulls up the spring rod, the auxiliary cam presses down on the spring rod, and the switching cam continues to move in the empty position; position 3: the main cam keeps pulling up the spring rod, the auxiliary cam keeps pressing down on the spring rod, the switching cam bearing pushes the horn-shaped contact, continues to rotate to disconnect the horn-shaped contact, and then pushes it into the other elastic contact; position 4: the main cam and auxiliary cam simultaneously press down on the spring rod, and the switching cam continues to push the horn-shaped contact forward; position 5: the main cam presses down on the spring rod, the auxiliary cam pulls up the spring rod, and the switching cam presses down on the other side of the horn-shaped contact symmetrically, and the switching is completed.

[0021] Preferably, the drive switching contact action is triggered by a lag, characterized in that when the drive switching contact is driven, the main cam, the auxiliary cam, and the switching cam move synchronously, the main cam and the auxiliary cam drive the spring rod to move up and down through the sliding groove, and the switching cam does not make contact with the horn-shaped contact in the middle, and the action is triggered when it rotates to a certain angle.

[0022] Implementing this invention has the following beneficial effects:

[0023] This invention provides a switching mechanism and method for on-load tap changers, which features interlocked switching actions and a delayed triggering method. This solves the problem of insufficient arc extinguishing time leading to contact damage in existing technologies, shortens the total switching time, and reduces the power required for the drive mechanism. Attached Figure Description

[0024] Figure 1 This is a front view of a switching mechanism and switching method for an on-load tap changer, which is related to the present invention.

[0025] Figure 2 This is a perspective view of a switching mechanism and switching method for an on-load tap changer, which is an invention of the present invention.

[0026] Figure 3 This is an exploded view of the switching contact assembly of a switching mechanism and switching method for an on-load tap changer, which is an invention of the present invention.

[0027] Figure 4 This is an exploded view of a spring rod assembly for a switching mechanism and switching method of an on-load tap changer, which is an invention of the present invention.

[0028] Figure 5This invention relates to a cam drive assembly for a switching mechanism and switching method for an on-load tap changer.

[0029] Figure 6 This invention relates to a switching mechanism and switching method for an on-load tap changer, and includes a diagram of a switching cam-driven switching contact assembly.

[0030] Figure 7 This invention relates to a schematic diagram of a switching mechanism and switching method for an on-load tap changer. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It is hereby declared that the directional terms such as up, down, left, right, front, back, inside, and outside used in this text are based solely on the accompanying drawings and are not intended to specifically limit the invention.

[0032] See Figure 1 ~ Figure 7 This invention provides a switching mechanism and switching method for on-load tap changers. The switching action is interlocked and the triggering method is delayed, which solves the problem of insufficient arc extinguishing time and damage to contacts in the prior art, shortens the total switching time, and reduces the power required by the drive mechanism.

[0033] To solve the above-mentioned technical problems, the present invention provides a switching mechanism and switching method for an on-load tap changer, characterized in that it includes a fixed base 1, a main fixed plate 4, a vacuum tube 2, a spring pull rod assembly 5, a cam drive assembly 6, and a switching contact assembly 3; the switching contact assembly 3 consists of an elastic contact 8, a horn-shaped switching contact 9, and a flexible connecting wire 10; the spring pull rod 5 has a built-in spring 13 and a movable pull pin 15, and a roller 17 is provided on the top; the cam drive assembly 6 consists of a main cam 19 and a secondary cam 18 that drive the spring pull rod roller 17, and a switching cam 20 that drives the switching contact; the vacuum tube 2 is installed above the fixed base 1, the main fixed plate 4 is installed above the fixed base 1, the switching contact assembly 3 is installed on the main fixed plate 4, the spring pull rod assembly 5 is connected to the moving contact of the vacuum tube 2, and the cam drive assembly 6 synchronously pulls the spring pull rod assembly 5 and the switching contact assembly 3 to move; the driving of the switching contact is triggered by a delayed method.

[0034] The switching mechanism and switching method for an on-load tap changer include a fixed base 1, a main fixed plate 4, a vacuum tube 2, a spring pull rod assembly 5, a cam drive assembly 6, and a switching contact assembly 3.

[0035] The switching mechanism and switching method for an on-load tap changer are described above. The switching contact assembly 3 consists of an elastic contact 8, a horn-shaped switching contact 9, and a flexible connecting wire 10.

[0036] The switching mechanism and switching method for an on-load tap changer include a spring rod 5 with a built-in spring 13, a movable pull pin 15, and a roller 17 on the top.

[0037] The switching mechanism and switching method for an on-load tap changer are described above. The cam drive assembly 6 consists of a main cam 19 and a secondary cam 18 that drive the spring pull rod roller 17, and a switching cam 20 that drives the switching contacts.

[0038] The switching mechanism and switching method for an on-load tap changer include a vacuum tube 2 mounted on a fixed base 1, a main fixed plate 4 mounted on the fixed base 1, a switching contact assembly 3 mounted on the main fixed plate 4, a spring pull rod assembly 5 connected to the moving contact of the vacuum tube 2, and a cam drive assembly 6 synchronously pulling the spring pull rod assembly 5 and the switching contact assembly 3 to move.

[0039] The switching mechanism and switching method for an on-load tap changer described herein employ a delayed triggering method to drive the switching contact action.

[0040] The main fixing plate 4 has a positioning groove in the middle for installing the switching contact assembly 3, and a guide limiting hole on each of the left and right sides to restrict the spring pull rod assembly 5 from sliding up and down within the guide limiting hole.

[0041] The switching contact assembly 3 includes a switching contact base 7, with symmetrical slots on both sides and a positioning pin hole in the middle. The slots are used to install a spring-loaded movable contact piece 8, and the positioning pin hole is used to install a horn-shaped switching contact 9.

[0042] The horn-shaped switching contact 9 has a movable pin hole in the middle and a flexible connecting wire 10 installed at the bottom. The other end of the flexible connecting wire 10 is connected to the moving contact of one of the vacuum tubes 2 to form a main circuit.

[0043] The spring pull rod assembly 5 includes a roller 17, a pull rod 12, a spring 13, a movable pull pin 15, and a sliding connecting sleeve 14. The roller 17 is installed at the top of the pull rod 12, and the pull rod 12 is rigidly connected to the sliding connecting sleeve 14. The spring 13 and the movable pull pin 15 are installed inside the sliding connecting sleeve 14, and the movable pull pin 15 passes through the sliding connecting sleeve 14 and is rigidly connected to the moving contact of the vacuum tube 2.

[0044] The movable pull pin 15 passes through the sliding connecting sleeve 14 and is rigidly connected to the moving contact of the vacuum tube 2. When the pull rod 12 moves upward, the sliding connecting sleeve 14 drives the movable pull pin 15 to pull the moving contact of the vacuum tube 2 upward in sync. When the pull rod 12 moves downward, the sliding connecting sleeve 14 moves downward in sync, compressing the internal spring 13. The spring 13 presses against the movable pull pin 15, applying spring force to the moving contact of the vacuum tube 2.

[0045] The main cam 19 is provided with a drive main slide groove, which has a symmetrical structure with a high middle and low sides.

[0046] The auxiliary cam 18 is provided with a drive auxiliary slide groove, which has a symmetrical structure with a lower middle section and higher sides.

[0047] A rolling bearing 21 is provided on the switching cam 20, and the rolling bearing pushes the horn-shaped contact 9 of the switching contact assembly to swing.

[0048] The cam drive assembly 6 synchronously pulls the spring rod assembly 5 and the switching contact assembly 3, causing the main cam 19, auxiliary cam 18, and switching cam 20 of the cam drive assembly 6 to rotate synchronously. Initial position 0: the main cam 19 presses down on the spring rod, the auxiliary cam 18 pulls up the spring rod, and the switching cam 20 presses down on one side of the horn-shaped contact. Position 1: the main cam 19 and auxiliary cam 18 simultaneously press down on the spring rod, and the switching cam 20 begins to rotate to the neutral position. Position 2: the main cam 19 pulls up the spring rod, the auxiliary cam 18 presses down on the spring rod, and the switching cam 20 continues to rotate. Continue to move without load; Position 3: Main cam 19 holds the spring lever up, and secondary cam 18 holds the spring lever down. Switching cam bearing 21 pushes the horn-shaped contact 9 and continues to rotate to disconnect the horn-shaped contact 9, then pushes it into the other elastic contact; Position 4: Main cam 19 and secondary cam 18 simultaneously press the spring lever down, and switching cam 20 continues to push the horn-shaped contact 9 forward; Position 5: Main cam 19 presses the spring lever down, secondary cam 18 holds the spring lever up, and switching cam 20 presses the horn-shaped contact 9 on the other side symmetrically, completing the switching.

[0049] The drive switching contact action is triggered in a delayed manner. When the drive switching contact is driven, the main cam 19, the auxiliary cam 18, and the switching cam 20 move synchronously. The main cam 19 and the auxiliary cam 18 drive the spring rod to move up and down through the sliding groove. The switching cam 20 has no contact with the horn-shaped contact 9 and needs to be rotated to a certain angle to trigger the action.

[0050] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A switching mechanism for an on-load tap changer, comprising a fixed base, a main fixed plate, a vacuum tube, a spring pull rod assembly, a cam drive assembly, and a switching contact assembly; characterized in that: A vacuum tube is installed above the fixed base, a main fixing plate is installed above the fixed base, a switching contact assembly is installed on the main fixing plate, a spring pull rod assembly is connected to the moving contact of the vacuum tube, and a cam drive assembly synchronously pulls the spring pull rod assembly and the switching contact assembly to move. The cam drive assembly includes a main cam, a secondary cam, and a switching cam, all of which rotate coaxially and synchronously. The main cam has a main slide groove that is high in the middle and low on both sides, and the auxiliary cam has an auxiliary slide groove that is low in the middle and high on both sides, and the two form an interlocked drive. The spring pull rod assembly includes a roller, a pull rod, a sliding connecting sleeve, a built-in spring, and a movable pull pin. When the pull rod is pulled up, it rigidly drives the moving contact of the vacuum tube. When the pull rod is pressed down, it compresses the spring to apply an elastic preload to the contact. The switching contact assembly includes an elastic contact and a horn-shaped switching contact; The switching cam uses angle lag triggering: in the early stage of cam rotation, it does not contact the horn-shaped switching contact. After idling to complete the arc extinguishing, it pushes the horn-shaped switching contact to swing and switch when it reaches the set angle. The entire switching process is executed in a five-position sequence: 0→1→2→3→4→5. The main / auxiliary cam controls the interlocking on / off of the vacuum tube. When the switching cam is at position 3, it pushes the horn-shaped switching contact to disconnect the original connection and connect to the elastic contact on the other side.

2. The switching mechanism of claim 1, wherein The main fixing plate has a positioning slot in the middle for installing the switching contact assembly, and guide limiting holes on the left and right sides to restrict the up and down sliding of the spring rod assembly.

3. The switching mechanism according to claim 1, characterized in that, The switching contact assembly includes a switching contact base, with symmetrical slots on both sides of the switching contact base. Spring-loaded elastic contacts are installed in the symmetrical slots on both sides, and a horn-shaped switching contact is installed in the central positioning pin hole.

4. The switching mechanism according to claim 1, characterized in that, The horn-shaped switching contact is connected to a flexible connecting wire at its lower end, and the other end of the flexible connecting wire is connected to the moving contact of the vacuum tube to form the main circuit.

5. The switching mechanism according to claim 1, characterized in that, The switching cam is equipped with a rolling bearing for driving the horn-shaped switching contact to swing.

6. A switching method for an on-load tap changer, applied to the switching mechanism according to any one of claims 1-5, characterized in that, Includes the following steps: Position 0: The main cam presses down the spring lever, the secondary cam pulls up the spring lever, and the switching cam presses down on one side of the horn-shaped switching contact; Position 1: The main and auxiliary cams simultaneously press the spring lever, and the switching cam rotates to the neutral position; Position 2: The main cam pulls up the spring lever, the secondary cam presses down the spring lever, and the switching cam keeps moving freely; Position 3: The main and auxiliary cams maintain an interlocked state. The switching cam pushes the horn-shaped switching contact to disconnect the original connection and connect to the elastic contact on the other side. Position 4: The main and auxiliary cams simultaneously press the spring lever, and the switching cam continues to push the contact into place; Position 5: The main cam presses down on the spring lever, the secondary cam pulls up the spring lever, and the switching cam presses down on the other side of the contact, completing the switching.

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