Split-phase environment-friendly gas ring main unit

Abstract

The invention discloses a split-phase type environment-friendly gas ring main unit which comprises a cabinet body, a three-phase upper inlet wire, a three-phase lower outlet wire and a three-phase grounding bar are arranged on the cabinet body, and a three-station circuit breaker and an isolating switch are installed in the cabinet body. A movable feeler lever of the isolating switch is rotated to a closing position in contact with the upper incoming line, a grounding position in contact with the grounding bar and an isolating position between the upper incoming line and the grounding bar respectively; the circuit breaker comprises an insulating cover, a support, a static contact, a vacuum arc-extinguishing chamber, a circuit breaker main shaft and an ejector rod, a switch rotating shaft of the circuit breaker and a switch rotating shaft of the disconnecting switch are metal rotating shafts, three phases are separated from one another and are directly connected without insulating materials, and the three phases are connected through the grounded metal rotating shafts. By means of the mode, split-phase arrangement is achieved, each phase is insulated to the ground, only ground breakdown, relay protection overcurrent and quick break occur, the protection effect can be rapidly achieved, the power failure time is shortened, the power failure range is shortened, the electric field design is uniform, the situation that an electric field is concentrated at the tip part is effectively avoided, and partial discharge is controlled.

Description

Technical Field

[0001] The invention relates to the technical field of ring main unit, and in particular to a phase-splitting environmentally friendly gas ring main unit. Background Art

[0002] As the dual carbon goals are gradually advanced, the electrical field is moving towards SF6-free. However, the insulation strength of environmentally friendly gases such as dry air or nitrogen is only 1 / 3 of that of SF6. In order to achieve the same insulation performance as SF6, the switch cabinet needs to increase the size of the switch cabinet and the internal electrical clearance. In the State Grid's standardization specifications, there is no major change in the external dimensions of the environmentally friendly gas insulated ring main cabinet and the SF6 ring main cabinet, resulting in many ring main cabinets directly applying the design layout of SF6 to make environmentally friendly gas cabinets. This practice is unreasonable and needs to be changed from the bottom-level design to make a new environmentally friendly gas switch cabinet that truly meets the State Grid's standardization technical requirements.

[0003] At present, most of the ring network cabinets on the market are non-phase-split type, with insulating partitions separating phases or phases to ground, and the rotating shaft is a non-metallic shaft. Since the conductive materials are directly connected through the insulating material, under long-term high-voltage operating conditions, it is possible to form a leakage current with non-self-recovering insulation properties, which may eventually lead to flashover or discharge breakdown. Due to the strong insulation capacity of SF6, the leakage current is very small and will not cause flashover and discharge breakdown. Its design concept is not completely suitable for environmentally friendly gas cabinets. If environmentally friendly gas is filled, the previously concealed "electrical clearance" and "creepage distance" problems will become prominent. If the single-phase short circuit is not disconnected in time, it may cause a short circuit fault in the other two phases.

[0004] Based on the above defects and shortcomings, it is necessary to improve the existing technology and design a phase-split environmentally friendly gas ring network cabinet. Summary of the invention

[0005] The main technical problem solved by the present invention is to provide a phase-split environmentally friendly gas ring network cabinet with a phase-split layout, which avoids the problem of relay protection being unable to protect when the phase-to-phase insulation is broken down, causing over-tripping, and prevents the upper switch from operating, causing the power outage to expand.

[0006] In order to solve the above technical problems, a technical solution adopted by the present invention is: to provide a phase-splitting environmentally friendly gas ring network cabinet, the phase-splitting environmentally friendly gas ring network cabinet includes a cabinet body, the cabinet body is provided with a three-phase upper incoming line, a three-phase lower outgoing line and a three-phase grounding bar, a three-position circuit breaker and an isolating switch are installed in the cabinet body, and the moving contact rod of the isolating switch is respectively rotated to a closing position in contact with the upper incoming line, to a grounding position in contact with the grounding bar, and to an isolating position between the upper incoming line and the grounding bar; the circuit breaker includes an insulating cover, a support, a static contact, a vacuum interrupter, a circuit breaker main shaft and a top rod, and a support is fixed on the upper crossbeam of the insulating cover. A seat is provided on the support, and a static contact is fixedly connected to the upper end of the pull rod in the vacuum interrupter chamber. A soft connection for connecting the lower outlet is fixed on the upper crossbeam of the insulating cover, and the soft connection is connected to the pull rod below the vacuum interrupter chamber. A circuit breaker main shaft is also provided in the cabinet, and the shift fork cam of the circuit breaker main shaft rotates to control the opening of the vacuum interrupter chamber, and performs upward closing or downward opening movement. The insulating cover fixes the push rod through an internal insert, and the push rod is stuck on the spring seat below the pull rod; the switch shafts of the circuit breaker and the isolating switch adopt metal shafts, the three phases are separated from each other, and are directly connected without insulating material, and the three phases are connected through a grounded metal shaft.

[0007] Preferably, the circuit breaker main shaft includes a circuit breaker shaft, a fork cam and a shielding layer. The circuit breaker shaft is made of metal and is formed through an integral process with an insulating material. A fork cam is installed at one end of the circuit breaker shaft close to the vacuum arc chamber. The circuit breaker shaft drives the fork cam to rotate, thereby driving the upper pull rod of the vacuum arc chamber to move up and down. A shielding layer for a uniform electric field is pre-embedded in the circuit breaker shaft, and the shielding layer is located between the fork cam and the circuit breaker shaft. The circuit breaker shaft on both sides of the fork cam is radially extended outward and provided with an insulating layer for increasing the creepage distance, and the insulating layer is rounded all around.

[0008] Preferably, the shift fork cam is provided with an opening for avoiding the spring seat on the pull rod, the shift fork cam and the push rod clamp the spring seat to limit it radially, the upper and lower planes of the shift fork cam are control surfaces, the control surfaces are inclined surfaces, and the stroke of the spring pull rod can be customized by modifying the control surface angle β; the shape of the shift fork cam is processed by end face rounding.

[0009] Preferably, the insulating cover is made of insulating material, the overall structure is rounded, and the insulating cover is fixed to the bracket inside the cabinet through an external insert.

[0010] Preferably, the support includes an upper support and a lower support, the upper and lower supports are connected by screws, and the upper and lower supports are rounded on all sides.

[0011] Preferably, the isolating switch includes an isolating switch shaft, a crank arm, a moving contact rod, an insulating pull rod, a shielding ring and a voltage equalizing cover. The isolating switch shaft is rotatably installed on the cabinet, and a three-position crank arm that rotates therewith is installed on the isolating switch shaft. The moving contact rod is rotatably installed on the static contact of the circuit breaker. The crank arm and the moving contact rod are rotatably connected through the insulating pull rod. The protruding end of the pull rod shaft pin at the connection between the crank arm and the insulating pull rod is covered with a shielding ring, and the outer end of the connecting piece under the contacts of the two moving contact rods in the same group is covered with a voltage equalizing cover. The shielding ring and the voltage equalizing cover are made of metal. The rotation angle of the moving contact rod is controlled by controlling the size of the crank arm, so as to control the entire movement process of closing-opening-grounding of the isolating switch.

[0012] Preferably, the static contact of the circuit breaker, the moving contact rod of the disconnector and the grounding knife of the grounding bar are all made of conductive materials and are chamfered.

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

[0014] Each phase is separated from each other and connected only by a metal shaft. The existence of the metal shaft solves the problem of phase-to-phase insulation breakdown. If a single-phase short circuit occurs, it will not spread to other phases. The arc of the short circuit will first pass through the metal shaft. The metal shaft is at ground potential, and a high-voltage ground breakdown occurs, triggering the relay action and interrupting the fault current, avoiding the failure of other phases caused by a single-phase fault and reducing the scope of power outage.

[0015] According to the design principle of relay protection in my country's substation, for the power system with neutral point insulation, the relay protection does not have the ability to sense phase-to-phase short circuit. Only when the accident expands to ground breakdown, the upper level protection system can take effect and cause over-level tripping. Therefore, the split-phase structure of the present invention makes the switch equipment break down to the ground as much as possible. The ground breakdown can make the relay protection trigger the fault current breaking faster, so that the power outage tripping is controlled at the current level, preventing over-level tripping caused by untimely disconnection of the switch at the current level, and reducing the power outage time and scope;

[0016] The uniform electric field design effectively avoids the concentration of the electric field at the tip, controls local discharge, and reduces the field strength as much as possible in a limited space. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of a phase-split environmentally friendly gas ring network cabinet.

[0018] Figure 2 This is a schematic diagram of the internal structure of a phase-split environmentally friendly gas ring network cabinet.

[0019] Figure 3 This is a schematic diagram of the internal structure of a phase-split environmentally friendly gas ring network cabinet from another perspective.

[0020] Figure 4The diagram is a partial structural diagram of the circuit breaker of a phase-split environmentally friendly gas ring main unit.

[0021] Figure 5 The diagram is a structural diagram of the main shaft portion of a circuit breaker of a phase-split environmentally friendly gas ring main unit.

[0022] Figure 6 The diagram is a schematic diagram of the fork cam structure of a phase-split environmentally friendly gas ring network cabinet.

[0023] Figure 7 The diagram is a partial structural diagram of a circuit breaker of a phase-split environmentally friendly gas ring main unit.

[0024] Figure 8 The figure is a schematic diagram of a shift fork cam of a phase-split environmentally friendly gas ring main unit.

[0025] Fig. 9 The figure is a schematic diagram of the isolating switch structure of a phase-split environmentally friendly gas ring network cabinet.

[0026] Fig.10 This is a working status diagram of the isolating switch of a phase-split environmentally friendly gas ring network cabinet.

[0027] Fig.11 The diagram is a schematic diagram of the operation of the isolating switch of a phase-split environmentally friendly gas ring main unit.

[0028] Among them, 1. cabinet, 2. upper incoming line, 3. lower outgoing line, 4. grounding bar, 5. circuit breaker, 51. insulating cover, 52. support, 53. static contact, 54. vacuum interrupter, 540. pull rod, 55. circuit breaker main shaft, 551. circuit breaker rotating shaft, 5510. insulating layer, 552. shift fork cam, 5520. control surface, 56. push rod, 6. disconnector, 61. disconnector rotating shaft, 62. crank arm, 63. moving contact rod, 64. insulating pull rod, 65. shielding ring, 66. equalizing cover. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0030] See also Figures 1 to 11 , the embodiment of the present invention includes:

[0031] A phase-splitting environmentally friendly gas ring network cabinet, the phase-splitting environmentally friendly gas ring network cabinet comprises a cabinet body 1, on which a three-phase upper incoming line 2, a three-phase lower outgoing line 3 and a three-phase grounding bar 4 are arranged, a three-position circuit breaker 5 and an isolating switch 6 are installed in the cabinet body 1, the isolating switch 6 rotates to drive the upper moving contact rod 63 to rotate, respectively rotating to a closing position in contact with the upper incoming line 2, to a grounding position in contact with the grounding bar 4 and to an isolating position between the upper incoming line 2 and the grounding bar 4; the circuit breaker 5 comprises an insulating cover 51, a support 52, a static contact 53, a vacuum interrupter 54, a circuit breaker main shaft 55 and a push rod 56, a support 52 is fixed on the upper crossbeam of the insulating cover 51, a static contact 53 is installed on the support 52, the static contact 53 is fixedly connected to the upper end of the pull rod in the vacuum interrupter 54, a soft connection for connecting the lower outgoing line 3 is fixed on the upper crossbeam of the insulating cover 51, and the soft connection is connected to the vacuum interrupter The pull rod 540 is connected below the arc chamber 54, and a circuit breaker main shaft 55 is also installed in the cabinet 1. The fork cam 552 of the circuit breaker main shaft 55 rotates to control the vacuum arc chamber 54 to open and close, and the insulating cover 51 fixes the top rod 56 through the internal insert, and the top rod 56 is stuck on the spring seat below the pull rod; the switch shafts of the circuit breaker 5 and the disconnector 6 adopt metal shafts, and the three phases are separated from each other and directly connected without insulating materials. The three phases are connected through a grounded metal shaft. The existence of the metal shaft solves the problem of phase-to-phase insulation breakdown (if a short circuit fault occurs in a single phase, it will not spread to other phases. The arc spread by the short circuit will first pass through the metal shaft. The metal shaft is at ground potential, and high voltage breakdown to the ground occurs, triggering the relay protection action, breaking the fault current, avoiding the accident from expanding to three phases, causing the upper switch to trip, and reducing the power outage time and scope).

[0032] The circuit breaker main shaft 55 includes a circuit breaker shaft 551, a fork cam 552 and a shielding layer. The circuit breaker shaft 551 is made of metal and is formed by an integral process with an insulating material. A fork cam 552 is installed at one end of the circuit breaker shaft 551 close to the vacuum arc chamber 54. The circuit breaker shaft 551 drives the fork cam 552 to rotate, thereby driving the upper pull rod 540 of the vacuum arc chamber 54 to move up and down. Since the high voltage and ground positions before and after the circuit breaker shaft 551 are close, a shielding layer for a uniform electric field is embedded in the circuit breaker shaft 551. The shielding layer is located between the fork cam 552 and the circuit breaker shaft 551 to prevent the electric field from concentrating at the tip part and control partial discharge. The circuit breaker shaft 551 on both sides of the fork cam 552 is radially extended outward with an insulating layer 5510 to increase the creepage distance. The insulating layer 5510 is rounded all around.

[0033] The shift fork cam 552 is fixed on the circuit breaker shaft 551 by an insert nut. The shift fork cam 552 is provided with an opening for avoiding the spring seat on the pull rod 540. The shift fork cam 552 and the push rod 56 clamp the spring seat to limit it radially. The upper and lower planes of the shift fork cam 552 are control surfaces 5520, and the control surface is an inclined surface. The center distance between the circuit breaker shaft 551 and the pull rod is L (known quantity), the opening / closing stroke a of the pull rod action (known quantity), the rotation angle α of the circuit breaker shaft 551 (the quantity to be solved), and the inclination angle β of the control surface of the shift fork cam 552 (the quantity to be solved) can be solved through plane geometric relations, such as Figure 8 As shown, the stroke of the spring pull rod can be customized by modifying the control surface angle β; the shape of the fork cam 552 is processed by end face rounding and a uniform electric field design to prevent the electric field from concentrating at the tip part and control local discharge.

[0034] The insulating cover 51 is made of insulating material, and the overall structure is rounded. The insulating cover 51 is fixed to the bracket inside the cabinet 1 through an external insert, and a uniform electric field design is used to prevent the electric field from concentrating at the tip part to control partial discharge.

[0035] The support 52 includes an upper support and a lower support, which are connected by screws to strengthen the fixed support of the static end position of the vacuum interrupter 54. The upper and lower supports are rounded around and designed with a uniform electric field to prevent the electric field from concentrating at the tip part and control partial discharge.

[0036] The isolating switch 6 comprises an isolating switch shaft 61, a crank arm 62, a moving contact rod 63, an insulating pull rod 64, a shielding ring 65 and a voltage-equalizing cover 66. The isolating switch shaft 61 is rotatably mounted on the cabinet 1 and driven to rotate by the isolating switch operating mechanism (omitted here). A three-position crank arm 62 is mounted on the isolating switch shaft 61 and rotates accordingly. The moving contact rod 63 is rotatably mounted on the static contact 53 of the circuit breaker 5. The crank arm 62 and the moving contact rod 63 are rotatably connected through the insulating pull rod 64. The pull rod shaft at the connection between the crank arm 62 and the insulating pull rod 64 The protruding end of the pin is sleeved with a shielding ring 65, and the outer end of the connecting piece below the contact point of the two moving contact rods 63 in the same group is sleeved with a voltage grading cover 66. The shielding ring 65 and the voltage grading cover 66 are made of metal material and are designed with a uniform electric field to prevent the electric field from concentrating at the tip part and control partial discharge. The center length L1 of the moving contact rod 63 (known quantity), the distance L2 from the rotating hole of the moving contact rod 63 to the fulcrum (known quantity), the length L3 of the insulating pull rod 64 (known quantity), the plane coordinate position (x, y) of the center A of the isolating switch shaft 61 (solved quantity), and the length L4 of the crank arm 62 (solved quantity), as shown in FIG. Fig.11As shown, by controlling the size of the crank arm 62, the mechanism input, that is, the movable contact rod 63, is rotated exactly 90°, so as to control the entire movement process of closing-opening-grounding of the isolating switch. The 90° output angle is more convenient for the selection of the isolating switch mechanism. The common three-station mechanisms on the market are all designed with a 90° output angle. As long as they meet the installation requirements, they can be adapted to the isolating switch. By controlling the size and position of the crank arm 62, the input angle of the isolating switch 6 can be changed to the output angle of the switch.

[0037] The static contact 53 of the circuit breaker 5, the moving contact rod 63 of the disconnector 6 and the grounding knife of the grounding bar 4 are all made of conductive materials and are chamfered, with a uniform electric field design to prevent the electric field from concentrating at the tip part and control partial discharge.

[0038] When a phase-split environmentally friendly gas ring network cabinet of the present invention is working, the isolating switch shaft 61 rotates, and the moving contact rod 63 is driven to move through the insulating pull rod 64, and the switch knife is controlled from top to bottom, which are respectively in the three states of closing, isolation, and grounding. The circuit breaker shaft 551 rotates, driving the fork cam 552 to rotate, and the upper plane / lower plane of the fork cam 552 contacts the spring seat, controlling the pull rod 540 to close the switch upward / open the switch downward.

[0039] Closing: The moving contact rod 63 of the disconnector 6 moves to the upper incoming line 2, and the circuit breaker shaft 551 of the circuit breaker main shaft 55 rotates to drive the circuit breaker to the closing position;

[0040] Isolation: The moving contact rod 63 of the isolating switch 6 rotates to the middle isolation position, and the circuit breaker shaft 551 of the circuit breaker main shaft 55 rotates to drive the circuit breaker to the opening position;

[0041] Grounding: The moving contact rod 63 of the disconnector 6 moves to the grounding bar 4, and the circuit breaker shaft 551 of the circuit breaker main shaft 55 rotates to drive the circuit breaker to the opening position.

[0042] The invention discloses a phase-splitting environmentally friendly gas ring network cabinet. The phase-splitting layout eliminates the concern about phase-to-phase insulation and focuses the problem on only considering the insulation relative to the ground, that is, only the breakdown to the ground will occur, thus reducing the power outage time and scope caused by the fault.

[0043] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A phase-splitting environmentally friendly gas ring main unit, characterized by: The invention comprises a cabinet (1), wherein a three-phase upper incoming line (2), a three-phase lower outgoing line (3) and a three-phase grounding bar (4) are arranged on the cabinet (1), a three-position circuit breaker (5) and an isolating switch (6) are installed in the cabinet (1), and a movable contact rod (63) of the isolating switch (6) is respectively rotated to a closing position in contact with the upper incoming line (2), to a grounding position in contact with the grounding bar (4), and to an isolating position between the upper incoming line (2) and the grounding bar (4); the circuit breaker (5) comprises an insulating cover (51), a support (52), a static contact (53), a vacuum interrupter (54), a circuit breaker main shaft (55) and a top rod (56), a support (52) is fixed on the upper crossbeam of the insulating cover (51), and the static contact (53) is installed on the support (52) The static contact (53) is fixedly connected to the upper end of the pull rod in the vacuum arc extinguishing chamber (54); a soft connection for connecting the lower outlet line (3) is fixed on the upper crossbeam of the insulating cover (51); the soft connection is connected to the pull rod below the vacuum arc extinguishing chamber (54); a circuit breaker main shaft (55) is also installed in the cabinet (1); the shift fork cam (552) of the circuit breaker main shaft (55) rotates to control the vacuum arc extinguishing chamber (54) to open and close, and to perform upward closing or downward opening movement; the insulating cover (51) fixes the top rod (56) through an internal insert, and the top rod (56) is stuck on the spring seat below the pull rod; the switch shafts of the circuit breaker (5) and the disconnector (6) are metal shafts, the three phases are separated from each other, and are directly connected without insulating material, and the three phases are connected through a grounded metal shaft; The circuit breaker main shaft (55) comprises a circuit breaker rotating shaft (551), a shift fork cam (552) and a shielding layer. The circuit breaker rotating shaft (551) is made of metal and is formed by an integral process with an insulating material. The shift fork cam (552) is installed at one end of the circuit breaker rotating shaft (551) close to the vacuum interrupter (54). The circuit breaker rotating shaft (551) drives the shift fork cam (552) to rotate, thereby driving the upper pull rod of the vacuum interrupter (54) to move up and down. The circuit breaker rotating shaft (551) is pre-buried with a shielding layer for a uniform electric field. The shielding layer is located between the shift fork cam (552) and the circuit breaker rotating shaft ( 551), the circuit breaker rotating shaft (551) on both sides of the fork cam (552) is radially extended outwardly to be provided with an insulating layer (5510) for increasing the creepage distance, and the insulating layer (5510) is chamfered on all sides; the fork cam (552) is provided with an opening for avoiding the spring seat on the pull rod, the fork cam (552) and the push rod (56) clamp the spring seat to limit it radially, the upper and lower planes of the fork cam (552) are control surfaces, the control surface is an inclined surface, and the stroke of the spring pull rod can be customized by modifying the control surface angle β; the outer shape of the fork cam (552) is processed by end face chamfering.

2. The phase-splitting environmentally friendly gas ring main unit according to claim 1, characterized in that: The insulating cover (51) is made of insulating material, and the overall structure is rounded. The insulating cover (51) is fixed to the inner bracket of the cabinet (1) via an external insert.

3. The phase-splitting environmentally friendly gas ring main unit according to claim 1 is characterized in that: The support (52) comprises an upper support and a lower support, the upper and lower supports are connected by screws, and the upper and lower supports are rounded around.

4. The phase-splitting environmentally friendly gas ring main unit according to claim 1, characterized in that: The isolating switch (6) comprises an isolating switch rotating shaft (61), a crank arm (62), a movable contact rod (63), an insulating pull rod (64), a shielding ring (65) and a voltage-equalizing cover (66); the isolating switch rotating shaft (61) is rotatably mounted on a cabinet (1); a crank arm (62) is mounted on the isolating switch rotating shaft (61) and rotates with three positions; the movable contact rod (63) is rotatably mounted on a stationary contact (53) of a circuit breaker (5); the crank arm (62) and the movable contact rod (63) are rotatably mounted on a stationary contact (53) of a circuit breaker (5); 63) is rotatably connected through an insulating pull rod (64); a shielding ring (65) is sleeved on the protruding end of the pull rod axle pin at the connection between the crank arm (62) and the insulating pull rod (64); a voltage equalizing cover (66) is sleeved on the outer end of the connecting piece below the contact points of the two moving contact rods (63) in the same group; the shielding ring (65) and the voltage equalizing cover (66) are made of metal material; by controlling the size of the crank arm (62), the rotation angle of the moving contact rod (63) is controlled, thereby achieving the control of the entire movement process of closing-opening-grounding of the disconnector.

5. The phase-splitting environmentally friendly gas ring main unit according to claim 1 is characterized in that: The static contact (53) of the circuit breaker (5), the moving contact rod (63) of the isolating switch (6) and the grounding knife of the grounding bar (4) are all made of conductive materials and are chamfered.

Images