A circuit breaker and three-phase switch

Abstract

The application relates to a circuit breaker and a three-phase switch. The circuit breaker is connected with an opening branch and a through-flow branch in parallel. The opening branch comprises two symmetrically arranged first vacuum arc-extinguishing chambers and a first transmission mechanism, a first connecting head of which is provided with a long waist hole to be slidably matched with a first rocker arm to drive a first movable contact to vertically move; the through-flow branch comprises two symmetrically arranged second vacuum arc-extinguishing chambers and a second transmission mechanism, a second connecting head of which is provided with a connecting shaft to be rotatably matched with a second rocker arm to drive a second movable contact to horizontally move. Input ends of the first and second driving rods are respectively used for being transmissionally connected with corresponding synchronous linkage shafts, the opening and closing timing of the two branches is controlled through the actions of external driving sources in sequence, the through-flow branch is opened first, and the opening branch is opened later. The conflict between the through-flow capacity and the opening capacity is effectively solved, the transmission is self-balanced, the synchronism is high, and the operating power and the volume are obviously reduced.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker technology, specifically to a circuit breaker and a three-phase switch. Background Technology

[0002] With the rapid growth of renewable energy installed capacity, pumped storage technology has become a key support for the construction of new power systems, and its role is becoming increasingly prominent. Among them, the core equipment, generator circuit breakers, has long been monopolized by foreign companies, and the domestic market for circuit breakers used in 300-450MW pumped storage units is basically dominated by foreign companies such as Hitachi and ABB.

[0003] Conventional SF6 generator circuit breakers have shortcomings in terms of environmental protection, mechanical and electrical lifespan. Using vacuum circuit breakers as generator outlet switches is a technically sound approach that aligns with future development trends. Vacuum breaking and SF6 breaking differ fundamentally in principle: vacuum possesses superior insulation properties, reducing arc erosion of contacts to milligram levels, thus effectively meeting the demands of pumped-storage power stations for frequent low-current interruptions daily. Furthermore, vacuum circuit breakers have smaller moving and stationary contact spacing and lower operating power, which helps improve breaking speed, control arcing time, and enhance adaptability to large-capacity units. Existing generator outlet vacuum circuit breakers are mostly single-tube vacuum interrupter structures, with a few being double-tube series structures, and their capacity is typically small.

[0004] To accommodate larger capacity units, existing technologies include vacuum circuit breakers with multiple vacuum interrupters connected in parallel. For example, a scheme disclosed in prior art document CN116844908A provides a vacuum interrupter group composed of multiple vacuum interrupters to further improve current carrying capacity and withstand voltage. Electrically, this group uses a matrix parallel connection with either parallel-then-series or series-then-parallel configurations. Physically, the vacuum interrupters are arranged uniformly in a ring, and a permanent magnet or repulsive force operating mechanism at the bottom drives a bidirectional scissor-shaped transmission mechanism mounted on an intermediate support via an insulated pull rod, thereby synchronizing the moving ends of the series-connected vacuum interrupters.

[0005] Although the parallel matrix layout of multiple arc-extinguishing chambers used in the aforementioned comparative documents theoretically improves the overall parameters, those skilled in the art have found in actual engineering applications and structural debugging that the arc-extinguishing chambers in this parallel system are completely homogeneous in electrical function. This means that when carrying a large rated current for a long time, if there are slight impedance or contact resistance deviations between the parallel branches, without complex active control intervention, it is very easy to cause severe current unevenness, which in turn leads to thermal failure consequences such as local temperature rise runaway. Summary of the Invention

[0006] The purpose of this invention is to provide a circuit breaker to solve the technical problems of existing circuit breakers for large-capacity units, which, despite employing multiple vacuum interrupters, still involve homogeneous parallel connection, cannot meet the requirements for carrying large rated currents, leading to uncontrolled temperature rise and complex operation; the purpose of this invention is also to provide a three-phase switch using this circuit breaker.

[0007] The technical solution of the circuit breaker of the present invention is as follows:

[0008] A circuit breaker includes: Opening branches and current-carrying branches connected in parallel between the incoming and outgoing ends; The disconnecting branch includes at least two first vacuum interrupters arranged in series and a first transmission mechanism for synchronously driving the opening and closing of the first vacuum interrupters; The flow path includes at least two parallel-connected second vacuum interrupters and a second transmission mechanism for synchronously driving the opening and closing of the second vacuum interrupters; The first transmission mechanism includes a first drive rod that can reciprocate axially, and the output end of the first drive rod is connected to the moving contact of each of the first vacuum interrupters through a first linkage part. The second transmission mechanism includes a second drive rod that can reciprocate axially, and the output end of the second drive rod is connected to the moving contact of each of the second vacuum interrupters through a second linkage part; The input ends of the first drive rod and the second drive rod are respectively used to be connected to their respective synchronous linkage shafts for transmission, so as to control the opening and closing actions of the disconnection branch and the current-carrying branch respectively through the sequential action of the synchronous linkage shafts, so that the first vacuum interrupter closes before the second vacuum interrupter and the first vacuum interrupter opens after the second vacuum interrupter.

[0009] Furthermore, it also includes a support frame, the flow path includes two symmetrical and horizontally arranged second vacuum interrupters on the support frame, the interruption path includes two symmetrical and vertically arranged first vacuum interrupters above the second vacuum interrupters; the first drive rod is located between the two first vacuum interrupters, and the second drive rod is located between the two second vacuum interrupters.

[0010] Furthermore, the first transmission mechanism and the second transmission mechanism are arranged side by side on the support frame, and the first drive rod and the second drive rod extend vertically downwards parallel to each other to the bottom of the support frame.

[0011] Furthermore, both the first linkage and the second linkage include: The connector is fixedly connected to the top end of the corresponding first and second drive rods; A pair of rocker arms are symmetrically arranged on both sides of the first and second drive rods, and the pair of rocker arms are rotatably mounted on the support frame of the corresponding branch through corresponding pivots. The first end of each rocker arm is rotatably or slidably assembled with the connector, and the second end of each rocker arm is rotatably connected to the moving contact of the vacuum interrupter on the corresponding side via a corresponding connecting rod.

[0012] Furthermore, the transmission ratio of the rocker arm rotating around the axis is 1:2, so that the moving speed and displacement of the corresponding first drive rod and the second drive rod are twice that of the corresponding connecting rod.

[0013] Furthermore, the connector of the first drive rod is provided with an elongated hole for sliding assembly of the first end of the corresponding rocker arm; The connector of the second drive rod has a connecting shaft that extends radially away from the second drive rod and is rotatably assembled to the first end of the corresponding rocker arm.

[0014] Furthermore, the first transmission mechanism and the second transmission mechanism are also connected to a bistable retaining unit to provide an axial locking force to the first drive rod or the second drive rod.

[0015] The technical solution of the three-phase switch of the present invention is as follows: The three-phase switch includes three sets of circuit breakers connected in parallel, and a synchronous linkage shaft that drives each set of circuit breakers to operate. The circuit breaker includes: a breaking branch and a current-carrying branch connected in parallel between the incoming and outgoing terminals. The disconnecting branch includes at least two first vacuum interrupters arranged in series and a first transmission mechanism for synchronously driving the opening and closing of the first vacuum interrupters; The flow path includes at least two parallel-connected second vacuum interrupters and a second transmission mechanism for synchronously driving the opening and closing of the second vacuum interrupters; The first transmission mechanism includes a first drive rod that can reciprocate axially, and the output end of the first drive rod is connected to the moving contact of each of the first vacuum interrupters through a first linkage part. The second transmission mechanism includes a second drive rod that can reciprocate axially, and the output end of the second drive rod is connected to the moving contact of each of the second vacuum interrupters through a second linkage part; The input ends of the first drive rod and the second drive rod are respectively used to be connected to their respective synchronous linkage shafts for transmission, so as to control the opening and closing actions of the disconnection branch and the current-carrying branch respectively through the sequential action of the synchronous linkage shafts, so that the first vacuum interrupter closes before the second vacuum interrupter and the first vacuum interrupter opens after the second vacuum interrupter.

[0016] The synchronous linkage shaft has two parts, which are respectively connected to the first drive rod and the second drive rod of the three sets of circuit breakers. It also includes two hydraulic drive mechanisms that are respectively controlled and connected to the synchronous linkage shaft.

[0017] Furthermore, it also includes a support frame, the flow path includes two symmetrical and horizontally arranged second vacuum interrupters on the support frame, the interruption path includes two symmetrical and vertically arranged first vacuum interrupters above the second vacuum interrupters; the first drive rod is located between the two first vacuum interrupters, and the second drive rod is located between the two second vacuum interrupters.

[0018] Furthermore, the first transmission mechanism and the second transmission mechanism are arranged side by side on the support frame, and the first drive rod and the second drive rod extend vertically downwards parallel to each other to the bottom of the support frame.

[0019] Furthermore, both the first linkage and the second linkage include: The connector is fixedly connected to the top end of the corresponding first and second drive rods; A pair of rocker arms are symmetrically arranged on both sides of the first and second drive rods, and the pair of rocker arms are rotatably mounted on the support frame of the corresponding branch through corresponding pivots. The first end of each rocker arm is rotatably or slidably assembled with the connector, and the second end of each rocker arm is rotatably connected to the moving contact of the vacuum interrupter on the corresponding side via a corresponding connecting rod.

[0020] Furthermore, the transmission ratio of the rocker arm rotating around the axis is 1:2, so that the moving speed and displacement of the corresponding first drive rod and the second drive rod are twice that of the corresponding connecting rod.

[0021] Furthermore, the connector of the first drive rod is provided with an elongated hole for sliding assembly of the first end of the corresponding rocker arm; The connector of the second drive rod has a connecting shaft that extends radially away from the second drive rod and is rotatably assembled to the first end of the corresponding rocker arm.

[0022] Furthermore, the first transmission mechanism and the second transmission mechanism are also connected to a bistable retaining unit to provide an axial locking force to the first drive rod or the second drive rod.

[0023] The beneficial effects of this application are as follows: Compared with the prior art, the circuit breaker involved in this application divides the circuit breaker into parallel breaking branches and current-carrying branches, with their respective independent drive rods and synchronous linkage shafts controlling their sequential operation. During closing, the breaking branch closes first to withstand the pre-breakdown arc; during opening, the current-carrying branch opens first, transferring the continuous high current to the breaking branch without arcing, and finally, the breaking branch completes the arc extinguishing. This parallel structure achieves decoupling and current shunting of current-carrying and arc-extinguishing functions, enabling the vacuum circuit breaker to safely achieve a rated continuous current carrying capacity of 16kA without using any harmful sulfur hexafluoride gas, while retaining extremely high short-circuit current breaking capacity.

[0024] Each of the interrupting branch and the flow-through branch requires only one independent main drive rod, which directly links multiple arc-extinguishing chambers within its branch through the first / second linkage. This centralized mechanical transmission design with one rod and multiple chambers ensures high-precision mechanical synchronization between the arc-extinguishing chambers through rigid constraints, eliminating the response delay and electromagnetic interference risks of the electronic controller. While significantly simplifying the mechanical structure and reducing assembly costs, it also ensures a high level of operational synchronicity. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a specific embodiment of the circuit breaker of the present invention; Figure 2 for Figure 1 A half-section view; Figure 3 for Figure 2 A schematic diagram of the structure of the first transmission mechanism; Figure 4 for Figure 2 A schematic diagram of the structure of the second transmission mechanism; Figure 5 for Figure 2 Schematic diagram of the structure of the bistable unit; Figure 6 This is a schematic diagram of a specific embodiment of the three-phase switch of the present invention.

[0026] In the diagram: 1-First vacuum interrupter; 11-First stationary contact; 12-First moving contact; 13-Stationary sliding contact finger; 14-Moving sliding contact finger; 15-Stationary overtravel disc spring; 2-First transmission mechanism; 21-First connecting rod; 22-First pin; 23-First rocker arm; 24-First rotating shaft; 25-First connector; 26-First drive rod; 3-Bridging conductor; 4-Second vacuum interrupter; 41-Second stationary contact; 42-Second moving contact; 43-Stationary sliding contact finger ; 44-Moving end sliding contact finger; 45-Static end overtravel disc spring; 5-Second transmission mechanism; 51-Second connecting rod; 52-Second pin; 53-Second rocker arm; 54-Second rotating shaft; 55-Connecting shaft; 56-Second connector; 57-Second drive rod; 6-Incoming conductor; 7-Opening and closing buffer unit; 8-Dual-stable holding unit; 10-Sealed tank; 16-Support frame; 17-Support insulator; 18-Outgoing conductor; 19-Synchronous linkage shaft; 20-Hydraulic drive mechanism. Detailed Implementation

[0027] 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 and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0029] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0030] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0031] Specific embodiments of the circuit breaker of the present invention: as follows Figures 1 to 5 As shown, it is mainly installed on the support frame 16. The support frame 16 is rigidly supported on the ground or foundation frame by the lower support insulator 17 to ensure the mechanical stability of the overall circuit breaker structure when subjected to high-speed impact.

[0032] The circuit breaker has two completely separate electrical branches connected in parallel between the incoming and outgoing ends: a breaking branch, which includes two symmetrically arranged first vacuum interrupters 1 and a first transmission mechanism 2 for synchronously driving the opening and closing of the first vacuum interrupters 1; and a current-carrying branch, which includes two symmetrically arranged second vacuum interrupters 4 and a second transmission mechanism 5 for synchronously driving the opening and closing of the second vacuum interrupters 4.

[0033] To achieve the most compact installation of the circuit breaker within the limited space of the enclosed busbar, this design employs an asymmetrical spatial folding design with one vertical and one horizontal component. Two symmetrical and side-by-side second vacuum interrupters 4 are horizontally positioned in the lower middle part of the support frame 16, their axes parallel to the horizontal plane and the mounting surface of the support frame 16. This horizontal arrangement allows the larger current-carrying portion to extend horizontally, fully utilizing the lateral space above the support base and reducing the overall vertical height of the unit. Directly above the two horizontally positioned second vacuum interrupters 4, two symmetrical first vacuum interrupters 1 are vertically positioned, their axes perpendicular to the horizontal plane and the mounting surface of the support frame 16.

[0034] The first transmission mechanism 2 includes a first drive rod 26 that can reciprocate axially. The output end of the first drive rod 26 is connected to the moving contact of each of the first vacuum interrupters 1 through a first linkage. The first drive rod 26 extends vertically and is located on the symmetrical center line between the two first vacuum interrupters 1. The second transmission mechanism 5 includes a second drive rod 57 that can reciprocate axially. The output end of the second drive rod 57 is connected to the moving contact of each of the second vacuum interrupters 4 through a second linkage. The second drive rod 57 also extends vertically and is located on the symmetrical center line between the two second vacuum interrupters 4.

[0035] This spatial layout achieves physical isolation between the interruption and current flow in terms of electromagnetic force and thermal field, avoiding the superposition and accumulation of heat and electromagnetic force generated by the two arc-extinguishing chambers during high-current operation, thereby greatly improving the temperature rise performance of the circuit breaker under continuous high-current operation.

[0036] Each of the two first vacuum interrupters 1 is equipped with a first stationary contact 11 and a first moving contact 12. To achieve low contact resistance and reliable conductivity under high current, a stationary sliding contact finger 13 is fitted on the outer circumference of the first stationary contact 11, and a moving sliding contact finger 14 is fitted on its moving end. One end of the first stationary contact 11 is in sliding contact with the stationary sliding contact finger 13, and the other end is in separable mating contact with the first moving contact 12; one end of the first moving contact 12 is in mating contact with the first stationary contact 11, and the other end is in sliding contact with the moving sliding contact finger 14.

[0037] To provide a constant contact pressure during the closing state, the stationary end of the first vacuum interrupter 1 is equipped with a stationary overtravel disc spring 15, which is composed of multiple standard disc springs stacked together. At the end of the closing process, the transmission mechanism drives the first moving contact 12 to continue moving, compressing the overtravel disc spring to store energy. This preload is then used to apply a rated mechanical contact clamping force to the mating contacts, effectively reducing the contact resistance between the contacts and preventing micro-bounce of the contacts caused by electro-repulsive forces.

[0038] Similarly, the interiors of the two horizontally positioned second vacuum interrupters 4 are also equipped with a second stationary contact 41, a second moving contact 42, a stationary sliding contact finger 43, a moving sliding contact finger 44, and a stationary overtravel disc spring 45, and their conduction and overtravel compression principles are completely consistent with those of the breaking side.

[0039] To achieve the series connection and support of the two sets of arc-extinguishing chambers in space, a bridging conductor 3 made of highly conductive copper is provided between the moving ends of the two first vacuum arc-extinguishing chambers 1 at the top. The moving end conductive rods of the two series-connected first vacuum arc-extinguishing chambers 1 are electrically connected to both sides of the bridging conductor 3, while the stationary and moving contacts on both sides of the two parallel second vacuum arc-extinguishing chambers 4 are connected to the cylindrical inlet conductor 6 and outlet conductor 18 made of cast aluminum, respectively.

[0040] These highly conductive conductors work together to form a primary conductive circuit. Under high rated current conditions, since the current-carrying branch is in a closed state and its circuit resistance is designed to be much smaller than that of the open branch, the load current mainly passes through the current-carrying branch, thereby reducing the overall heat generation by a factor of two and eliminating the potential for local thermal runaway.

[0041] The first transmission mechanism 2 includes a first drive rod 26 that reciprocates axially in the vertical direction. A first connector 25 is fixedly connected to the top of the first drive rod 26 by a high-strength thread. The first connector 25 is shaped like a carrying pole and has elongated slots that extend symmetrically in the horizontal direction.

[0042] Two first rotating shafts 24 are symmetrically mounted on the support frame 16. The middle portions of two horizontally symmetrically arranged first rocker arms 23 are rotatably mounted on their respective first rotating shafts 24. The first end (inner end) of each first rocker arm 23 is rotatably connected to a first connector 25 via a first pin 22, which passes through the elongated slot and can slide freely along the lateral extension direction of the slot. The second end (outer end) of the first rocker arm 23 is rotatably connected to the first moving contact 12 of the corresponding first vacuum interrupter chamber 1 via a first connecting rod 21.

[0043] When the external driving force pulls the first drive rod 26 vertically downward, the inner wall of the elongated hole of the first connector 25 pushes the two first pins 22 downward synchronously. Since the first pins 22 can slide horizontally within the elongated hole, they absorb and eliminate the horizontal displacement component that inevitably occurs when the first rocker arm 23 rotates around the first rotating shaft 24, thus achieving geometric decoupling between rotational and linear motion. The two first pins 22 drive the inner ends of the two first rocker arms 23 to move downward synchronously, causing the outer ends of the first rocker arms 23 to move upward synchronously. This, in turn, pulls the first moving contacts 12 of the two first vacuum interrupters 1 to move upward synchronously and linearly via the first connecting rod 21, achieving circuit breaking.

[0044] This symmetrical layout with a single tie rod and two rocker arms ensures that when the tie rod moves upward or downward, the horizontal components of the forces applied to the first connector 25 by the two symmetrical first rocker arms 23 are equal in magnitude and opposite in direction, resulting in self-cancellation along the central axis of the connector. This allows the first drive rod 26 to bear only pure axial tensile and compressive stress during high-speed reciprocating motion, with its lateral shear moment being almost zero, completely eliminating the risk of tie rod bending deformation and guide jamming caused by eccentric force.

[0045] In order to match the horizontal layout of the second vacuum interrupter 4, the second transmission mechanism 5 must convert the vertical reciprocating linear motion of the second drive rod 57 into the horizontal reciprocating linear motion of the second moving contact 42 with high precision.

[0046] For this purpose, a second connector 56 is fixed to the top of the second drive rod 57, and the second connector 56 has a connecting shaft 55 extending radially away from the second drive rod 57. Two second rotating shafts 54 are symmetrically mounted on the support frame 16. The middle portions of two second rocker arms 53 (preferably designed as L-shaped rocker arms or crank rocker arms) are rotatably mounted on the corresponding second rotating shafts 54. The first end of each second rocker arm 53 is rotatably mounted to the second connector 56 via the connecting shaft 55. The second end of each second rocker arm 53 is connected to the second connecting rod 51 via the second pin 52, and is rotatably connected to the second moving contact 42 of the corresponding horizontally placed second vacuum interrupter 4.

[0047] When the second drive rod 57 moves vertically downward, the second connector 56 pulls the connecting shaft 55 and the first ends of the two second rocker arms 53 downward synchronously. The second rocker arms 53 rotate around their fixed second pivot 54, and their second ends generate a horizontally outward arc motion. Through the linear guidance of the second connecting rod 51, this rotational motion is converted into pulling the second moving contacts 42 of the two horizontally placed second vacuum interrupters 4 to move horizontally outward, realizing synchronous horizontal opening on the current-flow side.

[0048] In this design, the transmission ratio of the first rocker arm 23 rotating around the first shaft 24 and the transmission ratio of the second rocker arm 53 rotating around the second shaft 54 ​​are both rigidly designed to be 1:2. That is, the lever arm length of the rocker arm connecting the drive rod is twice the lever arm length of the connecting rod connecting the moving contact. The vertical displacement and velocity of the drive rod are twice the corresponding axial displacement and velocity of the moving contact. This allows the moving contact end to maintain a reasonable small opening distance, while the drive rod end can perform smooth movement with a large stroke. Both the first transmission mechanism 2 and the bottom of the second transmission mechanism 5 are connected to a bistable holding unit 8. The bistable holding unit 8 is existing technology and includes a thrust holding spring 84, a connecting rod 86, a bistable seat 81, and a piston 85. The thrust holding spring 84 is limited and compressed within the bistable seat 81, its rear side is limited by a cover plate 83, and its front side moves back and forth with the connecting rod 86 and the piston 85. When the drive rod moves to the closing or opening end point, the thrust holding spring 84 releases its pre-compression stress, applying an axial self-locking tension or thrust to the drive rod. This ensures that under extreme accidents such as power failure or voltage loss, the contact pressure of the contacts never decreases, and the opening break never shifts due to gravity or electrodynamic force.

[0049] To protect the bistable holding unit 8 from the complex humid environment and dust of the power plant, a barrel-shaped sealed tank 10 is fitted on its outside.

[0050] Because of the 1:2 lever ratio, the speed of the drive rod is twice that of the contact, and the mechanical kinetic energy carried by the drive rod at the end point reaches four times that of the contact. To smoothly absorb this huge end-point kinetic energy, a closing / opening buffer unit 7 is also connected to the transmission mechanism. The closing / opening buffer unit 7 is equipped with a progressive multi-stage hydraulic damping piston, which outputs an exponentially increasing hydraulic damping resistance in the last 20% of the drive rod's stroke, smoothly converting kinetic energy into heat energy for absorption, completely eliminating contact bounce at the closing end point, and jointly ensuring the electrical life of the circuit breaker.

[0051] In other embodiments, the number of the first vacuum interrupter chamber 1 connected in series and the number of the second vacuum interrupter chamber 4 connected in parallel can be replaced by three, four or more vacuum interrupters, and the spatial arrangement can be changed from symmetrical horizontal and vertical arrangement to ring array arrangement, triangular matrix arrangement or staggered stacked arrangement.

[0052] In other embodiments, the first drive rod 26 and the second drive rod 57 extending vertically downwards in parallel with each other can be replaced by extending obliquely in parallel with each other, extending horizontally in a lateral manner, or extending in a coaxial nested telescopic manner, in order to adapt to the spatial orientation of different substation enclosed busbars.

[0053] In other embodiments, the first and second linkage parts formed by the pair of rocker arms and connecting rods can also be replaced by symmetrically arranged gear and rack pairs, bidirectional wedge sliding pairs, rolling groove wheel mechanisms or hinged four-bar mechanisms to complete the conversion of the reciprocating linear movement of the drive rod to the linear movement of the contact.

[0054] In other embodiments, the 1:2 transmission ratio of the rocker arm rotating about the axis can also be replaced by a 1:1.5, 1:3, 1:4 or other equal transmission ratios, or even by a non-linear variable transmission ratio cam linkage mechanism, so as to match the speed and holding force according to the contact opening distance of different arc-extinguishing chambers.

[0055] In other embodiments, the elongated hole on the connector of the first drive rod 26 and the connecting shaft 55 on the connector of the second drive rod 57 can be replaced by a T-shaped slide, a linear rolling guide mechanism, a universal ball joint or a cross universal coupling, respectively, to release the multi-dimensional displacement components generated when the rocker arm rotates.

[0056] Embodiments of the three-phase switch involved in this invention, such as... Figure 6 As shown, it includes three sets of circuit breakers arranged in parallel, and a synchronous linkage shaft 19 for driving the operation of each set of circuit breakers. The structure of the circuit breaker is the same as that of the circuit breaker in any embodiment of the above-mentioned circuit breaker, and will not be described in detail.

[0057] Specifically, there are two synchronous linkage shafts 19, which are respectively connected to the first drive rod 26 and the second drive rod 57 of the three sets of circuit breakers, and also include two hydraulic drive mechanisms 20 that are respectively controlled and connected to the synchronous linkage shafts 19.

[0058] The system utilizes two independent synchronous linkage shafts 19, namely the first synchronous linkage shaft 19 and the second synchronous linkage shaft 19, to achieve rigid linkage between the three phases: the first synchronous linkage shaft 19 runs horizontally through the three phases and is connected to the bottom input end of the first drive rod 26 of the three sets of circuit breakers respectively, ensuring that the six first vacuum interrupters 1 of the three phases operate in absolute mechanical synchronization; the second synchronous linkage shaft 19 is arranged in parallel, runs horizontally through the three phases, and is connected to the bottom input end of the second drive rod 57 of the three sets of circuit breakers respectively, ensuring that the six second vacuum interrupters 4 of the three phases operate in absolute mechanical synchronization.

[0059] When the circuit breaker is in a long-term closed and current-carrying state, most of the large current flows through the horizontally placed second vacuum interrupter chamber 4.

[0060] Phase 1: Disconnection of the current-carrying branch: When the tripping signal is issued, the hydraulic drive mechanism 20 on the current-carrying side is activated, driving the second synchronous linkage shaft 19 to rotate. The second synchronous linkage shaft 19 drives the second drive rods 57 of the three phases to move downwards synchronously. Through the 1:2 ratio transmission of the second connector 56, connecting shaft 55, and second rocker arm 53, the vertical motion is converted into horizontal motion, causing the moving contacts of the six second vacuum interrupters 4 of the three phases to retract horizontally and quickly outwards, thus disconnecting the current-carrying branch.

[0061] Second stage: Arc-free commutation: Since the disconnected branch (first vacuum interrupter 1) is still in a closed state, the weak arc voltage generated at the moment the current-carrying branch is disconnected quickly transfers all the current to the disconnected branch in series.

[0062] Third stage: Final arc extinguishing of the disconnecting branch: After the current-carrying branch is completely disconnected and the commutation is completed, the hydraulic drive mechanism 20 on the disconnecting side is activated, driving the first synchronous linkage shaft 19 to rotate. The first synchronous linkage shaft 19 pulls the first drive rod 26 of the three phases downward synchronously. The elongated hole of the first connector 25 pulls the first rocker arm 23 to rotate downward, causing the moving contacts of the first vacuum interrupter 1 connected in pairs of the three phases to retract synchronously and at high speed upward, and the arc is extinguished instantly in the vacuum interrupter, and the tripping is safely completed.

[0063] First stage: Pre-closing of the branch circuit: After the closing command is issued, the hydraulic drive mechanism 20 on the breaking side first drives the first synchronous linkage shaft 19 to rotate, pushes the first drive rod 26 upward, and the first connector 25 rigidly pushes the first pin 22 upward through the long waist hole, causing the first rocker arm 23 to rotate in the opposite direction, and quickly pushes the first moving contact 12 of the first vacuum interrupter 1 downward to the closing position, receiving the pre-breakdown arc and closing.

[0064] Second stage: Zero-voltage closing of the current-carrying branch: After the first vacuum interrupter 1 is fully in contact and begins to compress the overtravel disc spring, the hydraulic drive mechanism 20 on the current-carrying side then actuates, pushing the second drive rod 57 up through the connecting shaft 55. The second connecting head 56 and the second rocker arm 53 push the second moving contact 42 horizontally inward until it contacts the stationary contact. Since the series-connected breaking branch is already in a conducting state at this time, the current-carrying branch is safely closed in a zero-voltage (arc-free) state, completely avoiding the current-carrying contact being burned by the large closing current.

[0065] Phase 3: Overtravel Compression and Bistable Locking: The hydraulic drive mechanism 20 continues to push the pull rod higher, compressing the overtravel disc spring on the interruption side and the overtravel disc spring on the current-carrying side respectively. The bistable holding unit 8 flips and locks, and the closing operation ends.

[0066] In other embodiments, the two hydraulic drive mechanisms 20 that control the sequential movement of the linkage shafts can also be replaced by two independent permanent magnet operating mechanisms, electrically controlled high-pressure pneumatic operating mechanisms, or spring operating mechanisms driven by fast digital servo motors, so as to realize electromagnetic or pneumatic drive of the two sets of branch sequential actions.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A circuit breaker, characterized in that, include: Opening branches and current-carrying branches connected in parallel between the incoming and outgoing ends; The disconnecting branch includes at least two first vacuum interrupters arranged in series and a first transmission mechanism for synchronously driving the opening and closing of the first vacuum interrupters; The flow path includes at least two parallel-connected second vacuum interrupters and a second transmission mechanism for synchronously driving the opening and closing of the second vacuum interrupters; The first transmission mechanism includes a first drive rod that can reciprocate axially, and the output end of the first drive rod is connected to the moving contact of each of the first vacuum interrupters through a first linkage part. The second transmission mechanism includes a second drive rod that can reciprocate axially, and the output end of the second drive rod is connected to the moving contact of each of the second vacuum interrupters through a second linkage part; The input ends of the first drive rod and the second drive rod are respectively used to be connected to their respective synchronous linkage shafts for transmission, so as to control the opening and closing actions of the disconnection branch and the current-carrying branch respectively through the sequential action of the synchronous linkage shafts, so that the first vacuum interrupter closes before the second vacuum interrupter and the first vacuum interrupter opens after the second vacuum interrupter.

2. The circuit breaker according to claim 1, characterized in that, It also includes a support frame, the flow path includes two symmetrical and horizontally arranged second vacuum interrupters on the support frame, the interruption path includes two symmetrical and vertically arranged first vacuum interrupters above the second vacuum interrupters; the first drive rod is located between the two first vacuum interrupters, and the second drive rod is located between the two second vacuum interrupters.

3. The circuit breaker according to claim 2, characterized in that, The first transmission mechanism and the second transmission mechanism are arranged side by side on the support frame, and the first drive rod and the second drive rod extend vertically downward to the bottom of the support frame in parallel with each other.

4. The circuit breaker according to any one of claims 1-3, characterized in that, Both the first linkage and the second linkage include: The connector is fixedly connected to the top end of the corresponding first and second drive rods; A pair of rocker arms are symmetrically arranged on both sides of the first and second drive rods, and the pair of rocker arms are rotatably mounted on the support frame of the corresponding branch through corresponding pivots. The first end of each rocker arm is rotatably or slidably assembled with the connector, and the second end of each rocker arm is rotatably connected to the moving contact of the vacuum interrupter on the corresponding side via a corresponding connecting rod.

5. The circuit breaker according to claim 4, characterized in that, The transmission ratio of the rocker arm's rotation around the axis is 1:2, so that the moving speed and displacement of the corresponding first and second drive rods are twice that of the corresponding connecting rods.

6. The circuit breaker according to claim 4, characterized in that, The first drive rod has a long slotted hole on its connector head for sliding assembly of the first end of the corresponding rocker arm. The connector of the second drive rod has a connecting shaft that extends radially away from the second drive rod and is rotatably assembled to the first end of the corresponding rocker arm.

7. The circuit breaker according to claim 1, characterized in that, The first transmission mechanism and the second transmission mechanism are also connected to a bistable retaining unit to provide an axial locking force to the first drive rod or the second drive rod.

8. A three-phase switch, comprising three sets of circuit breakers connected in parallel, and a synchronous linkage shaft for driving the operation of each set of circuit breakers, characterized in that, The circuit breaker is the circuit breaker described in any one of claims 1-7. There are two synchronous linkage shafts, which are respectively connected to the first drive rod and the second drive rod of the three sets of circuit breakers. The circuit breaker also includes two hydraulic drive mechanisms that are respectively controlled and connected to the synchronous linkage shafts.

Images