Double-break direct-current magnetic field circuit breaker

Abstract

The invention discloses a double-fracture direct-current magnetic field circuit breaker which comprises a frame, a moving contact assembly, a static contact, an electric transmission mechanism, a closing and opening mechanism, a shunt tripping device, an auxiliary signal device and an arc extinguishing system. The two groups of static contacts are matched with the moving contacts in the two groups of moving contact assemblies and are arranged in the frame; according to the invention, the modular design is adopted, the arrangement is clear, the structure is simple and compact, each module mechanism can be independently maintained and replaced, and the circuit breaker has the characteristics of strong breaking capacity, high short-time endurance capacity, high breaking speed, long service life, high reliability and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic field circuit breakers, and in particular relates to a double-break DC magnetic field circuit breaker. Background Art

[0002] DC field circuit breakers are mainly used in deexcitation and rotor overvoltage protection devices for medium and large synchronous generators. They can close and carry current under normal circuit conditions. In the event of a circuit fault, they can cooperate with discharge resistors to transfer energy and deexcite.

[0003] The DC circuit breaker of the excitation system is one of the key equipment of the excitation system and plays a key role in the demagnetization of the unit due to an accident. However, the DC magnetic field circuit breakers used for excitation of large domestic units have shortcomings in breaking capacity, tolerance, breaking speed, life and reliability. Summary of the Invention

[0004] In view of the above deficiencies in the prior art, the present invention provides a double-break DC magnetic field circuit breaker that ensures the stability, safety and reliability of the DC transmission and distribution system and the DC power grid system.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a double-break DC magnetic field circuit breaker, including a frame providing insulation support and two groups of moving contact assemblies and two groups of tripping mechanisms arranged in the frame, and also including an electric transmission mechanism arranged in the frame, and a shunt tripping device and an arc extinguishing system are arranged above the frame; the moving contact assembly includes a moving contact and a "∪"-shaped base with waist-shaped holes on two side walls, and a locking shaft, a connecting shaft, a top rod and a sliding shaft located in the waist-shaped hole are arranged on the moving contact from top to bottom, and a rotating shaft is also fixed on the base, and a bent plate for driving the rotating shaft to rotate is fixed to the bottom tail end of the moving contact, and the rotating shaft is fixed to the base and rotated by the bent plate; the frame Two static contacts arranged relative to the moving contact are also provided inside; the closing and opening mechanism includes a bracket, a tension spring and a closing and opening spring whose ends are fixed on the bracket, and a locking device movably connected to the bracket, the locking device has a T-shaped connecting rod, the front end of the locking device is provided with a stepped portion that abuts against the locking shaft, the bottom end of the locking device is connected to the tension spring, the free end of the closing and opening spring is connected to the connecting shaft, and a driving block located at the free end of the top rod is connected below the bracket; the electric transmission mechanism includes a cam driven by a motor and a driven rod connected to the cam, and the driven rod is movably connected to the driving block; the shunt tripping device consists of a push-type shunt tripper and a pull-type shunt tripper that respectively provide push and pull forces to the T-shaped connecting rod.

[0006] The double-break DC magnetic field circuit breaker also has auxiliary signal devices symmetrically arranged on both sides of the moving contact assembly within its frame. The auxiliary signal device consists of a camshaft connected to the rotating shaft and a micro switch installed on the camshaft. The auxiliary signal device is directly connected to the rotating shaft through the hexagonal hole on the camshaft, thereby driving the micro switch to perform signal conversion.

[0007] In the double-break DC magnetic field circuit breaker, the middle part of the locking device is fixed to the corresponding bracket through an axle pin or a rolling bearing, and the two sets of locking devices are fixedly connected through a T-shaped connecting rod to achieve synchronous coaxial rotation.

[0008] In the described double-break DC magnetic field circuit breaker, the front stepped portion of the locking device is overlapped on the upper portion of the locking shaft, and the middle and lower portions are connected to the bracket via a tension spring to provide contact pressure between the locking device and the locking shaft.

[0009] The double-break DC magnetic field circuit breaker has a locking shaft installed on the upper part of the moving contact through a rolling bearing and can rotate flexibly. The top rod is placed below the connecting shaft and one end is installed on the lower middle part of the moving contact through a rolling bearing, and the other end contacts the driving block during the closing process.

[0010] In the described double-break DC magnetic field circuit breaker, its push-type shunt release and pull-type shunt release are fixed in the middle of the two-pole closing and opening mechanism. The push-type shunt release provides a rightward push force for the T-shaped connecting rod, and the pull-type shunt release provides a rightward pull force for the T-shaped connecting rod. The rear-pull shunt release is provided with a manual operating lever to realize emergency manual opening of the circuit breaker.

[0011] The described double-break DC magnetic field circuit breaker, its electric transmission mechanism also includes a roller shaft connected to the cam through a roller assembly, the roller assembly is fixedly installed in the middle of the roller shaft and below the cam, a group of active rods are provided at each end of the roller shaft and fixedly connected, one end of the two driven rods is respectively connected to the two active rods through an axle pin, and the other end is connected to the driving block through an axle pin.

[0012] The double-break DC magnetic field circuit breaker has two arc extinguishing systems, which are respectively arranged on the upper parts of the corresponding moving contact assemblies and static contacts and fixed on the main frame.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The present invention adopts modular design, has clear levels, simple and compact structure, and each module mechanism can be repaired and replaced easily.

[0015] 2. The present invention is based on a dual-redundant shunt release design, which has high tripping reliability and effectively ensures system safety.

[0016] 3. The present invention has a strong breaking capacity and can break a maximum short-circuit current of 70kA DC. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 It is a partial structural diagram of the electric transmission mechanism, closing and opening mechanism, moving contact assembly, static contact and shunt tripping device of the present invention;

[0019] Figure 3 It is a structural schematic diagram of the electric transmission mechanism of the present invention;

[0020] Figure 4 It is a structural schematic diagram of the auxiliary signal device of the present invention.

[0021] The figures are marked as follows: 1—frame, 2—moving contact assembly, 21—moving contact, 22—locking shaft, 23—connecting shaft, 24—top rod, 25—sliding shaft, 26—base, 27—bent plate, 28—rotating shaft, 3—static contact, 4—electric transmission mechanism, 41—cam, 42—roller assembly, 43—roller shaft, 44—active rod, 45—driven rod, 46—connecting piece, 5—closing and opening mechanism, 51—bracket, 52—locking device, 53—tension spring, 54—closing and opening spring, 55—driving block, 56—T-type connecting rod, 6—shunt tripping device, 61—push-type shunt tripping device, 62—pull-type shunt tripping device, 7—auxiliary signal device, 71—micro switch, 72—camshaft, 8—arc extinguishing system. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; in addition, in the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] like Figure 1As shown, this embodiment provides a double-break DC magnetic field circuit breaker, including a frame 1, a moving contact assembly 2, a static contact 3, an electric transmission mechanism 4, a closing and opening mechanism 5, a shunt trip device 6, an auxiliary signal device 7, and an arc extinguishing system 8. The frame 1 provides insulation support for the entire double-break DC magnetic field circuit breaker structure.

[0025] like Figure 2 As shown, the moving contact assembly 2 is composed of a moving contact 21 , a locking shaft 22 , a connecting shaft 23 , a push rod 24 , a sliding shaft 25 , a base 26 , a bent plate 27 and a rotating shaft 28 . The movable contact assembly 2 comprises two groups. The base 26 is shaped like an ∪ and the movable contact 21 is placed in the waist-shaped holes on the two side walls of the base 26 via a sliding shaft 25, enabling the movable contact 21 to slide and rotate relative to the base 26. The locking shaft 22 is mounted on the upper part of the movable contact 21 via a needle bearing and can rotate flexibly. The connecting shaft 23 is placed below the locking shaft 22 and is tightly fixed to the middle part of the movable contact 21. The ejector rod 24 is placed below the connecting shaft 23 and one end is mounted on the lower middle part of the movable contact 21 via a needle bearing, and the other end contacts the drive block 55 during the closing process. The bent plate 27 is fixed to the bottom tail end of the movable contact 21. The base 26 also has a rotating shaft 28. The bottom tail end of the movable contact 21 is fixed with a bent plate 27 that drives the rotating shaft 28 to rotate. The rotating shaft 28 is fixed to the base 26 and is rotated by the bent plate 27. The two groups of static contacts 3 are arranged in the frame 1 relative to the movable contacts 21 in the two groups of movable contact assemblies 2.

[0026] like Figure 3 As shown, the electric transmission mechanism 4 comprises a cam 41, a roller assembly 42, a roller shaft 43, an active rod 44, a driven rod 45, and a connector 46. The cam 41 in the electric transmission mechanism 4 is directly connected to the motor fixed to the frame 1 and rotates unidirectionally counterclockwise around the roller shaft 43. The connector 46 is welded to the roller shaft 43 to form a single, shaped component. The roller assembly 42 is fixedly mounted to the middle of the roller shaft 43 and below the cam 41 via the connector 46, forming a crank-connecting rod structure. A set of active rods 44 are fixedly connected at each end of the roller shaft 43. The active rods 44 are connected to driven rods 45, which are movably connected to drive blocks 55. One end of each driven rod 45 is connected to the two active rods 44 via a pin, and the other end is connected to the corresponding drive blocks 55 in the closing and opening mechanisms 5. The cam 41, roller assembly 42, and active rod 44 are parallel and perpendicular to the roller shaft 43.

[0027] The closing and opening mechanism 5 is composed of a bracket 51, a locking device 52, a tension spring 53, a closing and opening spring 54, a drive block 55 and a T-shaped connecting rod 56. The two combined opening and closing mechanisms 5 are fixed to the frame 1 through the two moving contact assemblies 2 respectively. The closing and opening springs 54 in the closing and opening mechanisms 5 are connected to the connecting shaft 23 in the moving contact assembly 2. The middle parts of the two sets of locking devices 52 are fixed to the corresponding brackets 51 through shaft pins or rolling bearings. The front end stepped portion overlaps the upper part of the locking shaft 22. The middle and lower parts are connected to the bracket 51 through the tension spring 53, and provide contact pressure between the locking device 52 and the locking shaft 22. During the closing process of the moving contact 21, the locking shaft 22 and the locking shaft 22 are connected. The latching device 52 generates rolling friction and realizes the engagement and locking of the moving contact 21 at a specific position. The engagement and locking position of the latching device 52 and the latching shaft 22 is a stepped design, which can realize reliable operation of the circuit breaker; the driving blocks 55 on the two combined tripping mechanisms 5 are respectively placed directly below the top rod 24 in the moving contact assembly 2 and centered in the middle. The driving blocks 55 are correspondingly connected to the driven rod 45. The two sets of latching devices 52 are fixedly connected by a T-shaped connecting rod 56 to realize synchronous operation of the two latching devices 52.

[0028] The shunt trip device 6 is composed of a push-type shunt release 61 and a pull-type shunt release 62. The push-type shunt release 61 and the pull-type shunt release 62 in the shunt trip device 6 are fixed in the middle of the two-pole closing and opening mechanism 5 and are arranged on the left and right sides of the T-shaped connecting rod 56. The push-type shunt release 61 provides a rightward push force for the T-shaped connecting rod 56, and the pull-type shunt release 62 provides a rightward pull force for the T-shaped connecting rod 56. The rear-pull shunt release 62 is provided with a manual operating lever to realize emergency manual opening of the circuit breaker.

[0029] like Figure 4 As shown, the auxiliary signal device 7 consists of a micro switch 71 and a cam shaft 72. The two auxiliary signal devices 7 are symmetrically arranged on both sides of the moving contact assembly 2 and fixed to the frame 1. The hexagonal hole on the cam shaft 72 is directly connected to the rotating shaft 28 fixed to the base 26, thereby driving the micro switch 71 to switch states.

[0030] There are two groups of arc extinguishing systems 8 , which are respectively arranged on the upper parts of the corresponding moving contact assemblies 2 and static contacts 3 and fixed on the main frame 1 .

[0031] As a specific implementation method, Figure 2 、 3As shown in Figures 4 and 5, the operation process of the magnetic field circuit breaker is that the cam 41 in the closing and opening mechanism 5 rotates counterclockwise under the drive of the motor, and the cam 41 drives the roller assembly 42 to move downward, and drives the driving block 55 to rotate clockwise through the mechanical connecting rods such as the roller shaft 43, the active rod 44, and the driven rod 45 until it contacts the push rod 24; the push rod 24 continues to move clockwise with the driving block 55, and the moving contact 21 moves to the left under the thrust of the push rod 24, while the closing and opening spring 54 stretches and stores energy until the front step surface of the locking device 52 falls on the locking shaft 22, completing the closing and energy storage process of the magnetic field circuit breaker contact system; when the push rod 24 moves to After it is in the same straight line position as the driving block 55, a "dead point" mechanism is formed. As the push rod 24 continues to move, the "over-dead point" process is completed, and the moving contact 21 completes the closing action under the action of the closing and opening spring 54; after closing, the energy stored in the closing and opening spring 54 is not completely released, and the contact force between the moving contact 21 and the static contact 3 is still maintained. When the T-shaped connecting rod 56 rotates to the right under the joint action of the push-type shunt release 61 and the pull-type shunt release 62, it drives the locking device 52 to rotate counterclockwise and disengage from the locking shaft 22. The moving contact 21 completes the opening action under the action of the closing and opening spring 54, and the stored energy is completely released at this time.

[0032] The present invention adopts modular design with clear layers and simple and compact structure. Each module can be independently repaired and replaced. It has the advantages of strong ultimate breaking capacity, high short-time tolerance, fast breaking speed, long life and high reliability.

[0033] The above examples are merely illustrative of the present invention and do not limit the scope of protection of the present invention. Any design that is identical or similar to the present invention falls within the scope of protection of the present invention.

Claims

1. A double-break DC magnetic field circuit breaker, characterized in that: The invention comprises a frame (1), two sets of moving contact assemblies (2) and a closing / opening mechanism (5) arranged in the frame (1), and an electric transmission mechanism (4) arranged in the frame (1). A shunt tripping device (6) and an arc extinguishing system (8) are arranged above the frame (1); the moving contact assembly (2) comprises a moving contact (21) and a base (26) provided with a waist-shaped hole, the moving contact (21) is provided with a locking shaft (22), a connecting shaft (23), a top rod (24) and a sliding shaft (25) located in the waist-shaped hole in sequence from top to bottom, the base (26) is also fixed with a rotating shaft (28), and a bent plate (27) for driving the rotating shaft (28) to rotate is fixed to the bottom of the moving contact (21); two static contacts (3) arranged relative to the moving contact (21) are also provided in the frame (1); the closing / opening mechanism (5) comprises a bracket ( 51), a tension spring (53) whose end is fixed on the bracket (51) and a closing / opening spring (54) connected to the connecting shaft (23), the bracket (51) is movably connected to the T-shaped connecting rod (56) through a locking device (52), the front end of the locking device (52) is provided with a stepped portion that abuts against the locking shaft (22), the bottom end of the locking device (52) is connected to the tension spring (53), and a driving block (55) located at the free end of the top rod (24) is connected below the bracket (51); the electric transmission mechanism (4) includes a cam (41) driven by a motor and a driven rod (45) connected to the cam (41), and the driven rod (45) is movably connected to the driving block (55); the shunt tripping device (6) is composed of a push-type shunt tripper (61) and a pull-type shunt tripper (62) that respectively provide push and pull forces to the T-shaped connecting rod (56).

2. A double-break DC magnetic field circuit breaker according to claim 1, characterized in that: The frame (1) also includes auxiliary signal devices (7) symmetrically arranged on both sides of the moving contact assembly (2). The auxiliary signal device (7) is composed of a cam shaft (72) connected to the rotating shaft (28) and a micro switch (71) installed on the cam shaft (72).

3. The double-break DC magnetic field circuit breaker according to claim 1, characterized in that: The middle portion of the locking device (52) is fixed to the bracket (51) via an axle pin or a rolling bearing, and the two sets of locking devices (52) are fixedly connected via a T-shaped connecting rod (56) to achieve synchronous coaxial rotation.

4. A double-break DC magnetic field circuit breaker according to claim 3, characterized in that: The front stepped portion of the locking device (52) is overlapped on the locking shaft (22), and the middle and lower portion is connected to the bracket (51) through a tension spring (53) to provide contact pressure between the locking device (52) and the locking shaft (22).

5. A double-break DC magnetic field circuit breaker according to claim 1, 2, 3 or 4, characterized in that: The locking shaft (22) is mounted on the upper portion of the moving contact (21) via a rolling bearing, and one end of the push rod (24) is mounted on the lower portion of the moving contact (21) via a rolling bearing.

6. The double-break DC magnetic field circuit breaker according to claim 5, characterized in that: The push-type shunt release (61) and the pull-type shunt release (62) are fixed in the middle of the closing and opening mechanism (5); the push-type shunt release (61) provides a rightward push force for the T-shaped connecting rod (56); and the pull-type shunt release (62) provides a rightward pull force for the T-shaped connecting rod (56).

7. The double-break DC magnetic field circuit breaker according to claim 6, characterized in that: The electric transmission mechanism (4) further comprises a roller shaft (43) connected to the cam (41) via a roller assembly (42), the roller assembly (42) being fixed to the middle of the roller shaft (43) and below the cam (41), a set of active rods (44) being provided at each end of the roller shaft (43), and a driven rod (45) being connected to the active rod (44) and the driving block (55) via an axle pin.

8. The double-break DC magnetic field circuit breaker according to claim 7, characterized in that: The arc extinguishing system (8) has two groups, which are respectively arranged on the upper parts of the corresponding moving contact assembly (2) and the static contact (3).

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