A switch unit and switchgear

Abstract

A switch unit and a switch cabinet, the switch unit is arranged in the switch cabinet, the switch unit comprises: a static contactor having at least one contact piece; at least one set of knife switches movable between a closed position and an open position to contact or separate from the corresponding contact piece to make the switch unit in a closed state or an open state; wherein the static contactor further comprises a heat sink, and a chamfer is provided between the heat sink and the contact piece, and the heat sink is configured to dissipate heat at the static contactor to the outside.

Description

Technical Field

[0001] This utility model relates to a switch unit and a switch cabinet, and more specifically, to a switch unit and a switch cabinet with better heat dissipation performance. Background Technology

[0002] In medium-voltage switchgear, good insulation and heat dissipation performance are crucial. Sulfur hexafluoride (SF6) has good insulation and heat dissipation properties, and is therefore widely used in medium-voltage switchgear. However, SF6 contributes significantly to the greenhouse effect, with a global warming potential 25,200 times that of carbon dioxide. To meet environmental protection requirements, the gas used to fill medium-voltage switchgear is being replaced with dry air, but this has led to a decrease in the insulation and heat dissipation performance of the switchgear.

[0003] Therefore, it is desirable to propose a switching unit that improves upon the shortcomings of the aforementioned prior art. Utility Model Content

[0004] According to a first aspect of the present invention, a switching unit is provided, comprising: a stationary contact having at least one contact piece; at least one set of knife switches movable between a closed position and an open position to contact or separate from the corresponding contact piece, so that the switching unit is in a closed state or an open state; wherein the stationary contact further comprises a heat sink, the heat sink and the contact piece having a chamfer, the heat sink being configured to dissipate heat at the stationary contact to the outside.

[0005] According to this design, by incorporating heat sinks, the heat dissipation area of ​​the stationary contact is increased, thereby improving the heat dissipation rate of the stationary contact and ultimately enhancing the heat dissipation performance of the switching unit. Furthermore, the chamfering between the heat sink and the contact plate prevents sharp points from concentrating the electric field near them, thus improving the insulation performance of the switching unit.

[0006] In some designs, the heat sink can be perpendicular to the contact plate.

[0007] In some designs, the heat sink can be positioned such that when the switch is in the closed position, it restricts the switch from rotating in the opposite direction to the open position.

[0008] According to this design, the heat sink can also be used to prevent the knife switch from rotating further after it has moved from the open position to the closed position, thus improving the safety of the switching unit.

[0009] In some designs, the switching unit may also include a heat sink that contacts the outer surface of a heat sink fin, allowing heat from the stationary contact to be transferred to the heat sink via the heat sink fin.

[0010] According to this scheme, by arranging a heat sink for the switching unit, the heat generated at the stationary contact is further dissipated to the outside, thereby improving the heat dissipation performance of the switching unit.

[0011] In some designs, the radiator may include internal fins and two external fins, with the two external fins arranged on both sides of the internal fins along a first direction perpendicular to the contact plate.

[0012] In some designs, the internal fins can form multiple parallel internal grooves, which are arranged side by side along a first direction, and each internal groove extends along a second direction perpendicular to the heat sink.

[0013] In some designs, the outer fins may have a plate-shaped fin body that is parallel to the contact plate, and multiple parallel external grooves are formed in the fin body, with the external grooves extending along a closed path.

[0014] In some designs, the projection of the inner fin onto the plane parallel to the contact plate lies within the projection of the outer fin onto the plane parallel to the contact plate.

[0015] According to this design, the internal fins are partially surrounded by the external fins to prevent the protrusions in the internal fins from causing electric field concentration, thereby improving the insulation performance of the switching unit.

[0016] In some designs, the outer periphery of the outer fin has a first arc portion and a second arc portion, the first arc portion being located outside the second arc portion along a first direction, and a smooth transition is formed between the first arc portion and the second arc portion.

[0017] According to this design, the outer fins have a smooth shape without sharp points, thus avoiding the concentration of electric field at the tips and improving the insulation performance of the switching unit.

[0018] In some designs, the radius of the first arc portion can be larger than the radius of the second arc portion.

[0019] According to this scheme, the electric field distribution around the switching unit is more uniform, which further improves the insulation performance of the switching unit.

[0020] In some designs, a gap may exist between the heat sink and the contact plate.

[0021] According to this design, the gap between the heat sink and the contact plate facilitates airflow to carry away heat, thereby improving the heat dissipation performance of the switching unit.

[0022] In some designs, the stationary contact may have one contact piece, which forms an L-shaped structure with the heat sink. Alternatively, the stationary contact may have two contact pieces, which form a U-shaped structure with the heat sink.

[0023] In some designs, the stationary contact may also have a connecting piece, with the connecting piece, contact piece, and heat sink perpendicular to each other, and the connecting piece electrically connected to the bus bushing.

[0024] According to a second aspect of the present invention, a switch cabinet is provided, wherein the switch unit described in the first aspect of the present invention is arranged in the switch cabinet.

[0025] According to this scheme, the heat dissipation performance of the switch cabinet is improved because the switch unit is equipped with heat sinks and radiators.

[0026] In some designs, the switch cabinet can be filled with dry air.

[0027] According to this plan, because the switchgear has good heat dissipation performance, sulfur hexafluoride is no longer needed as a filling gas in the switchgear, which reduces the emission of sulfur hexafluoride as a greenhouse gas and meets the corresponding green and environmental protection requirements. Attached Figure Description

[0028] Figure 1A A schematic diagram of a switching unit according to a first embodiment of the present invention is shown;

[0029] Figure 1B Another schematic diagram of the switching unit according to the first embodiment of the present invention is shown;

[0030] Figure 2 A schematic diagram of a switching unit according to a second embodiment of the present invention is shown; Figure 3 A schematic diagram of a switching unit according to a third embodiment of the present invention is shown;

[0031] Figure 4 A schematic diagram of a switching unit according to a fourth embodiment of the present invention is shown;

[0032] Figure 5 A schematic diagram of a switching unit according to a fifth embodiment of the present invention is shown;

[0033] Figure 6 A schematic diagram of a switching unit according to a sixth embodiment of the present invention is shown;

[0034] Figure 7 A schematic diagram of a heat sink according to an embodiment of the present invention is shown;

[0035] Figure 8 A front view of a heat sink according to an embodiment of the present invention is shown;

[0036] Figure 9 A top view of a heat sink according to an embodiment of the present invention is shown.

[0037] Figure Labels

[0038] 10 Radiators

[0039] 11 Internal fins

[0040] 12 Internal grooves

[0041] 13 External fins

[0042] 14. Fin body

[0043] 15 External groove

[0044] 17 First arc section

[0045] 18 Second arc section

[0046] 100 Switching Unit

[0047] 110 stationary contact

[0048] 112 Contact Piece

[0049] 113 Chamfer

[0050] 114 Heatsink

[0051] 116 Connecting piece

[0052] 117 Connecting hole

[0053] 118 busbar bushing

[0054] 120 disconnect switch

[0055] 200 Switching Unit

[0056] 210 stationary contact

[0057] 212 First Contact Piece

[0058] 213 Second Contact Piece

[0059] 216 Connecting piece

[0060] 217 Connecting hole

[0061] 220 disconnect switch

[0062] 300 Switching Unit

[0063] 310 stationary contact

[0064] 312 contact pad

[0065] 314 heatsink

[0066] 316 connecting piece

[0067] 317 Connecting hole

[0068] 320 disconnect switch assembly

[0069] 322 First disconnect switch

[0070] 324 Second disconnect switch

[0071] 400 Switching Unit

[0072] 410 stationary contact

[0073] 412 First Contact Piece

[0074] 413 Second Contact Piece

[0075] 416 Connecting piece

[0076] 417 Connecting hole

[0077] 420 disconnect switch assembly

[0078] 422 First disconnect switch

[0079] 424 Second disconnect switch

[0080] 500 Switching Unit

[0081] 510 stationary contact

[0082] 512 First Contact Piece

[0083] 513 Second Contact Piece

[0084] 516 Connecting piece

[0085] 517 Connecting hole

[0086] 520 disconnect switch assembly

[0087] 522 First disconnect switch

[0088] 524 Second disconnect switch

[0089] 600 Switching Unit

[0090] 610 stationary contact

[0091] 612 First Contact Piece

[0092] 613 Second Contact Piece

[0093] 616 Connecting piece

[0094] 617 Connecting hole

[0095] 620 disconnect switch assembly

[0096] 622 First disconnect switch

[0097] 624 Second disconnect switch

[0098] 626 Third disconnect switch

[0099] 628 Fourth disconnect switch Detailed Implementation

[0100] To make the objectives, solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise stated, the terms used herein have their ordinary meanings in the art. The same reference numerals in the drawings represent the same parts.

[0101] For clarity, unless otherwise explicitly stated, the directional terms used in this document are defined as follows: the first direction is the direction perpendicular to the contact plate, the second direction is the direction perpendicular to the heat sink, and the third direction is the direction perpendicular to the connecting plate.

[0102] Figure 1A A schematic diagram of a switching unit 100 according to a first embodiment of the present invention is shown. The switching unit 100 is used to control the on and off of a circuit, the current carried by which the circuit can be approximately between 630A and 800A. The switching unit 100 mainly includes a stationary contact 110 and a set of knife switches 120, the knife switches 120 being rotatable to move between a closed position and an open position. In the closed position, the knife switches 120 are in contact with the stationary contact 110, thereby turning on the circuit. In the open position, the knife switches 120 are separated from the stationary contact 110, thereby turning off the circuit. Each knife switch 120 includes two blades arranged side by side, and in the closed position, the stationary contact 110 is sandwiched between the two blades.

[0103] The stationary contact 110 mainly includes a contact piece 112, a heat sink 114, and a connecting piece 116. A chamfer is provided between the contact piece 112, the heat sink 114, and the connecting piece 116. Preferably, the contact piece 112, the heat sink 114, and the connecting piece 116 are perpendicular to each other (i.e., the contact piece 112 is perpendicular to the heat sink 114 and the connecting piece 116, the heat sink 114 is perpendicular to the connecting piece 116 and the contact piece 112, and the connecting piece 116 is perpendicular to the contact piece 112 and the heat sink 114) to roughly form a corner structure. The contact piece 112 and the heat sink 114 roughly form an L-shaped structure. The chamfer 113 between the heat sink 114 and the contact piece 112 (e.g., ...) Figure 1B (As shown) This avoids the presence of sharp points that would cause the electric field to concentrate near those points, thereby improving the insulation performance of the switching unit 100.

[0104] Contact piece 112 is configured to contact knife switch 120. Specifically, when knife switch 120 is in the closed position, the two blades of knife switch 120 clamp contact piece 112 of stationary contact 110. Heat sink 114 is configured to dissipate heat from stationary contact 110 to the outside. The presence of heat sink 114 increases the heat dissipation area of ​​stationary contact 110, thereby increasing the heat dissipation performance of switching unit 100. Furthermore, the position of heat sink 114 is configured such that when knife switch 120 is in the closed position, it restricts knife switch 120 from continuing to rotate in the opposite direction to the open position (i.e., as...). Figure 1A As shown, this limits the knife switch 120 from rotating further to the left. In this way, the heat sink 114 can also be used to prevent further rotation of the knife switch 120 after it has moved from the open position to the closed position, improving the safety of the switching unit 100. The connecting piece 116 has a connecting hole 117, through which the bus bushing 118 is electrically connected to the connecting piece 116.

[0105] Figure 2 A schematic diagram of a switching unit 200 according to a second embodiment of the present invention is shown. The switching unit 200 is used to control the on and off states of a circuit, the current of which can be approximately between 630A and 800A. The switching unit 200 mainly includes a stationary contact 210 and a knife switch 220, which is rotatable to move between a closed position and an open position. In the closed position, the knife switch 220 contacts the stationary contact 210, thereby turning on the circuit. In the open position, the knife switch 220 separates from the stationary contact 210, thereby turning off the circuit. One knife switch 220 includes two blades arranged side by side, and in the closed position, the stationary contact 210 is sandwiched between the two blades.

[0106] The stationary contact 210 mainly includes a first contact piece 212, a second contact piece 213, a heat sink (which is not visible due to being blocked by the second contact piece 213), and a connecting piece 216. The first contact piece 212 and the second contact piece 213 are arranged parallel to each other, and the heat sink and the connecting piece 216 are arranged between the first contact piece 212 and the second contact piece 213. A chamfer is provided between the first contact piece 212, the heat sink, and the connecting piece 216. Preferably, the first contact piece 212, the heat sink, and the connecting piece 216 are perpendicular to each other (i.e., the first contact piece 212 is perpendicular to the heat sink and the connecting piece 216, the heat sink is perpendicular to the connecting piece 216 and the first contact piece 212, and the connecting piece 216 is perpendicular to the contact piece 212 and the heat sink) to roughly form a corner structure. The first contact piece 212, the second contact piece 213, and the heat sink roughly form a U-shaped structure. The chamfer between the heat sink and the first contact plate 212 and the second contact plate 213 avoids the presence of sharp points that would cause the electric field to concentrate near the sharp points, thereby improving the insulation performance of the switching unit 200.

[0107] The first contact piece 212 is configured to contact the knife switch 220. Specifically, when the knife switch 220 is in the closed position, the two blades of the knife switch 220 clamp the first contact piece 212 of the stationary contact 210. A heat sink is configured to dissipate heat from the stationary contact 210 to the outside. The presence of the heat sink 214 increases the heat dissipation area of ​​the stationary contact 210, thereby increasing the heat dissipation performance of the switching unit 200. Furthermore, the position of the heat sink is configured such that when the knife switch 220 is in the closed position, it restricts the knife switch 220 from continuing to rotate in the opposite direction to the open position (i.e., as...). Figure 2 As shown, this limits the knife switch 220 from rotating further to the left. In this way, the heat sink can also be used to prevent further rotation of the knife switch 220 after it has moved from the open position to the closed position, improving the safety of the switching unit 200. Although the second contact piece 213 is not used for electrical connection with the knife switch 220, it increases the heat dissipation area of ​​the stationary contact 210, thereby improving the heat dissipation performance of the switching unit 200. Alternatively, when in the closed position, the two blades of the knife switch 220 can also clamp the second contact piece 213. The connecting piece 216 has a connecting hole 217, through which the bus bushing (not shown) is electrically connected to the connecting piece 216.

[0108] Figure 3 A schematic diagram of a switching unit 300 according to a third embodiment of the present invention is shown. The switching unit 300 is used to control the on and off of a circuit, and the circuit can carry a current of up to 1250A. The switching unit 300 mainly includes a stationary contact 310, a knife switch assembly 320, and a heat sink 10 (the specific structure of the heat sink 10 will be referred to below). Figures 7 to 9 (Described in detail), the switch assembly 320 is rotatable to move between a closed position and an open position. In the closed position, the switch assembly 320 contacts the stationary contact 310, thereby making the circuit conductive. In the open position, the switch assembly 320 separates from the stationary contact 310, thereby breaking the circuit. The switch assembly 320 includes a first switch 322 and a second switch 324, each switch including two blades arranged side by side. In the closed position, the two blades of the first switch 322 and the two blades of the second switch 324 respectively clamp the stationary contact 310.

[0109] The stationary contact 310 mainly includes a contact piece 312, a heat sink 314, and a connecting piece 316. A chamfer is provided between the contact piece 312, the heat sink 314, and the connecting piece 316. Preferably, the contact piece 312, the heat sink 314, and the connecting piece 316 are perpendicular to each other (i.e., the contact piece 312 is perpendicular to the heat sink 314 and the connecting piece 316, the heat sink 314 is perpendicular to the connecting piece 316 and the contact piece 312, and the connecting piece 316 is perpendicular to the contact piece 312 and the heat sink 314) to roughly form a corner structure. The contact piece 312 and the heat sink 314 roughly form an L-shaped structure. The chamfer between the heat sink 314 and the contact piece 312 avoids sharp points that could cause the electric field to concentrate near those points, thereby improving the insulation performance of the switching unit 300.

[0110] The contact piece 312 is configured to contact the knife switch assembly 320. Specifically, when the knife switch assembly 320 is in the closed position, the two blades of the first knife switch 322 and the two blades of the second knife switch 324 respectively clamp the contact piece 312 of the stationary contact 310. The outer surface of the heat sink 314 contacts the heat sink 10. The heat generated at the stationary contact 310 is transferred to the heat sink 10 via the heat sink 314, and then dissipated to the outside by the heat sink 10, thereby improving the heat dissipation performance of the switching unit 300. A gap may exist between the heat sink 10 and the contact piece 312. The gap between the heat sink 10 and the contact piece 312 facilitates airflow to carry away heat, further improving the heat dissipation performance of the switching unit 300. In addition, the position of the heat sink 314 is configured such that when the knife switch assembly 320 is in the closed position, it restricts the knife switch assembly 320 from continuing to rotate in the opposite direction to the open position (i.e., as shown in the image). Figure 3 As shown, this limits the knife switch assembly 320 from rotating further to the left. In this way, the heat sink 314 can also be used to prevent further rotation of the knife switch assembly 320 after it has moved from the open position to the closed position, improving the safety of the switch unit 300. The connecting piece 316 has a connecting hole 317, through which the bus bushing (not shown) is electrically connected to the connecting piece 316.

[0111] Figure 4 A schematic diagram of a switching unit 400 according to a fourth embodiment of the present invention is shown. The switching unit 400 is used to control the on and off of a circuit, and the circuit can carry a current of up to 1250A. The switching unit 400 mainly includes a stationary contact 410, a knife switch assembly 420, and a heat sink 10 (the specific structure of the heat sink 10 will be referred to below). Figures 7 to 9(Described in detail), the switch assembly 420 is rotatable to move between a closed position and an open position. In the closed position, the switch assembly 420 contacts the stationary contact 410, thereby making the circuit conductive. In the open position, the switch assembly 420 separates from the stationary contact 410, thereby breaking the circuit. The switch assembly 420 includes a first switch 422 and a second switch 424, each switch including two blades arranged side by side. In the closed position, the two blades of the first switch 422 and the two blades of the second switch 424 respectively clamp the stationary contact 410.

[0112] The stationary contact 410 mainly includes a first contact piece 412, a second contact piece 413, a heat sink (which is not visible due to being blocked by the second contact piece 413), and a connecting piece 416. The first contact piece 412 and the second contact piece 413 are arranged parallel to each other, and the heat sink and the connecting piece 416 are arranged between the first contact piece 412 and the second contact piece 413. A chamfer is provided between the first contact piece 412, the heat sink, and the connecting piece 416. Preferably, the first contact piece 412, the heat sink, and the connecting piece 416 are perpendicular to each other (i.e., the first contact piece 412 is perpendicular to the heat sink and the connecting piece 416, the heat sink is perpendicular to the connecting piece 416 and the first contact piece 412, and the connecting piece 416 is perpendicular to the contact piece 412 and the heat sink) to roughly form a corner structure. The first contact piece 412, the second contact piece 413, and the heat sink roughly form a U-shaped structure. The chamfer between the heat sink and the first contact plate 412 and the second contact plate 413 avoids the presence of sharp points that would cause the electric field to concentrate near the sharp points, thereby improving the insulation performance of the switching unit 400.

[0113] The first contact piece 412 is configured to contact the knife switch assembly 420. Specifically, when the knife switch assembly 420 is in the closed position, the two blades of the first knife switch 422 and the two blades of the second knife switch 424 respectively clamp the first contact piece 412 of the stationary contact 410. The outer surface of the heat sink contacts the heat sink 10. The heat generated at the stationary contact 410 is transferred to the heat sink 10 via the heat sink and then dissipated to the outside by the heat sink 10, thereby improving the heat dissipation performance of the switching unit 400. A gap may exist between the heat sink 10 and the first contact piece 412 and the second contact piece 413. The gap between the heat sink 10 and the first contact piece 412 and the second contact piece 413 facilitates airflow to carry away heat, further improving the heat dissipation performance of the switching unit 400. In addition, the position of the heat sink is configured such that when the knife switch assembly 420 is in the closed position, it restricts the knife switch assembly 420 from continuing to rotate in the opposite direction to the open position (i.e., as shown in the image). Figure 4As shown, this limits the knife switch assembly 420 from further rotation to the left. In this way, the heat sink can also be used to prevent further rotation of the knife switch assembly 420 after it has moved from the open position to the closed position, improving the safety of the switching unit 400. Although the second contact piece 413 is not used for electrical connection with the knife switch assembly 420, it increases the heat dissipation area of ​​the stationary contact 410, thereby improving the heat dissipation performance of the switching unit 400. Alternatively, when in the closed position, the two blades of the first knife switch 422 and the two blades of the second knife switch 424 can also respectively clamp the second contact piece 413. The connecting piece 416 is provided with a connecting hole 417, through which the bus bushing (not shown) is electrically connected to the connecting piece 416.

[0114] Figure 5 A schematic diagram of a switching unit 500 according to a fifth embodiment of the present invention is shown. The switching unit 500 is used to control the on and off of a circuit, and the circuit can carry a current of up to 1250A. The switching unit 500 mainly includes a stationary contact 510, a knife switch assembly 520, and a heat sink 10 (the specific structure of the heat sink 10 will be referred to below). Figures 7 to 9 (Described in detail), the switch assembly 520 is rotatable to move between a closed position and an open position. In the closed position, the switch assembly 520 contacts the stationary contact 510, thereby making the circuit conductive. In the open position, the switch assembly 520 separates from the stationary contact 510, thereby breaking the circuit. The switch assembly 520 includes a first switch 522 and a second switch 524, each switch including two blades arranged side by side. In the closed position, the two blades of the first switch 522 and the two blades of the second switch 524 respectively clamp the stationary contact 510.

[0115] The stationary contact 510 mainly includes a first contact piece 512, a second contact piece 513, a heat sink (which is not visible due to being blocked by the second contact piece 513), and a connecting piece 516. The first contact piece 512 and the second contact piece 513 are arranged parallel to each other, and the heat sink and the connecting piece 516 are arranged between the first contact piece 512 and the second contact piece 513. A chamfer is provided between the first contact piece 512, the heat sink, and the connecting piece 516. Preferably, the first contact piece 512, the heat sink, and the connecting piece 516 are perpendicular to each other (i.e., the first contact piece 512 is perpendicular to the heat sink and the connecting piece 516, the heat sink is perpendicular to the connecting piece 516 and the first contact piece 512, and the connecting piece 516 is perpendicular to the contact piece 512 and the heat sink) to roughly form a corner structure. The first contact piece 512, the second contact piece 513, and the heat sink roughly form a U-shaped structure. The chamfer between the heat sink and the first contact plate 512 and the second contact plate 513 avoids the presence of sharp points that would cause the electric field to concentrate near the sharp points, thereby improving the insulation performance of the switching unit 500.

[0116] The first contact piece 512 and the second contact piece 513 are configured to contact the knife switch assembly 520. Specifically, when the knife switch assembly 520 is in the closed position, the two blades of the first knife switch 522 clamp the first contact piece 512 of the stationary contact 510, and the two blades of the second knife switch 524 clamp the second contact piece 513 of the stationary contact 510. The outer surface of the heat sink contacts the heat sink 10. The heat generated at the stationary contact 510 is transferred to the heat sink 10 via the heat sink, and then dissipated to the outside by the heat sink 10, thereby improving the heat dissipation performance of the switching unit 500. A gap may exist between the heat sink 10 and the first contact piece 512 and the second contact piece 513. The gap between the heat sink 10 and the first contact piece 512 and the second contact piece 513 facilitates airflow to carry away heat, further improving the heat dissipation performance of the switching unit 500. In addition, the position of the heat sink is configured such that when the knife switch assembly 520 is in the closed position, it restricts the knife switch assembly 520 from continuing to rotate in the opposite direction to the open position (i.e., as shown in the image). Figure 5 As shown, this limits the knife switch assembly 520 from rotating further to the left. In this way, the heat sink can also be used to prevent further rotation of the knife switch assembly 520 after it has moved from the open position to the closed position, improving the safety of the switch unit 500. The connecting piece 516 has a connecting hole 517, through which the bus bushing (not shown) is electrically connected to the connecting piece 516.

[0117] Figure 6 A schematic diagram of a switching unit 600 according to a sixth embodiment of the present invention is shown. The switching unit 600 is used to control the on and off of a circuit, and the circuit can carry a current of up to 3150A. The switching unit 600 mainly includes a stationary contact 610, a knife switch assembly 620, and a heat sink 10 (the specific structure of the heat sink 10 will be referred to below). Figures 7 to 9 (Described in detail), the switch assembly 620 is rotatable to move between a closed position and an open position. In the closed position, the switch assembly 620 contacts the stationary contact 610, thereby making the circuit conductive. In the open position, the switch assembly 620 separates from the stationary contact 610, thereby making the circuit disconnected. The switch assembly 620 includes a first switch 622, a second switch 624, a third switch 626, and a fourth switch 628, each switch including two blades arranged side by side. In the closed position, the two blades of the first switch 622, the two blades of the second switch 624, the two blades of the third switch 626, and the two blades of the fourth switch 628 respectively clamp the stationary contact 610.

[0118] The stationary contact 610 mainly includes a first contact piece 612, a second contact piece 613, a heat sink (which is not visible due to being blocked by the second contact piece 613), and a connecting piece 616. The first contact piece 612 and the second contact piece 613 are arranged parallel to each other, and the heat sink and the connecting piece 616 are arranged between the first contact piece 612 and the second contact piece 613. A chamfer is provided between the first contact piece 612, the heat sink, and the connecting piece 616. Preferably, the first contact piece 612, the heat sink, and the connecting piece 616 are perpendicular to each other (i.e., the first contact piece 612 is perpendicular to the heat sink and the connecting piece 616, the heat sink is perpendicular to the connecting piece 616 and the first contact piece 612, and the connecting piece 616 is perpendicular to the contact piece 612 and the heat sink) to roughly form a corner structure. The first contact piece 612, the second contact piece 613, and the heat sink roughly form a U-shaped structure. The chamfer between the heat sink and the first contact plate 612 and the second contact plate 613 avoids the presence of sharp points that would cause the electric field to concentrate near the sharp points, thereby improving the insulation performance of the switching unit 600.

[0119] The first contact piece 612 and the second contact piece 613 are configured to contact the knife switch assembly 620. Specifically, when the knife switch assembly 620 is in the closed position, the two blades of the first knife switch 622 and the two blades of the third knife switch 626 respectively clamp the first contact piece 612 of the stationary contact 610, and the two blades of the second knife switch 624 and the two blades of the fourth knife switch 628 respectively clamp the second contact piece 613 of the stationary contact 610. The outer surface of the heat sink is in contact with the heat sink 10. The heat generated at the stationary contact 610 is transferred to the heat sink 10 via the heat sink, and then dissipated to the outside by the heat sink 10, thereby improving the heat dissipation performance of the switching unit 600. A gap may exist between the heat sink 10 and the first contact piece 612 and the second contact piece 613. The gap between the heat sink 10 and the first contact piece 612 and the second contact piece 613 facilitates airflow to carry away heat, further improving the heat dissipation performance of the switching unit 600. Furthermore, the heat sink is positioned such that when the switch assembly 620 is in the closed position, it restricts the switch assembly 620 from continuing to rotate in the opposite direction to the open position (i.e., as shown in the image). Figure 6 As shown, this limits the knife switch assembly 620 from rotating further to the left. In this way, the heat sink can also be used to prevent further rotation of the knife switch assembly 620 after it has moved from the open position to the closed position, improving the safety of the switch unit 600. A connection hole 617 is provided on the connecting piece 616, through which the bus bushing (not shown) is electrically connected to the connecting piece 616.

[0120] Figure 7A schematic diagram of a radiator 10 according to an embodiment of the present invention is shown. The working mechanism of the radiator 10 is described below using the third embodiment as an example. It should be understood that the working mechanism of the radiator 10 in the fourth, fifth, and sixth embodiments is similar to that in the third embodiment. The radiator 10 includes an inner fin 11 and two outer fins 13, with the outer fins 13 arranged along a first direction on both sides of the inner fin 11. The inner fin 11 forms a plurality of mutually parallel inner grooves 12, which extend along a second direction. The inner grooves 12 can also be designed in other shapes, as long as the airflow channel is vertical to facilitate convection between hot and cold gases. Furthermore, the central portion of the inner fin 11 contacts the heat sink 314 of the stationary contact 310, thereby transferring the heat generated at the stationary contact 310 to the inner fins 11 and outer fins 13 of the radiator 10 via the heat sink 314, and then dissipating it to the outside. The outer fins 13 have plate-shaped fin bodies 14, which are parallel to the contact plates 312 of the stationary contact 310. Optionally, the fin body 14 may be generally triangular, with the three vertices of the triangle rounded to prevent electric field concentration at the sharp points, which could degrade the insulation performance of the switching unit 300. The fin body 14 has a plurality of parallel external grooves 15 extending along a closed path (e.g., along a generally triangular closed path). Furthermore, the height of the ribs within the external grooves 15 does not exceed that of the fin body 14 to prevent electric field concentration caused by the ribs, which could degrade the insulation performance of the switching unit 300.

[0121] Figure 8 and Figure 9 The front and top views of the heat sink 10 according to an embodiment of the present invention are shown respectively. The projection of the inner fins 11 onto a plane parallel to the contact plate 312 lies within the projection of the outer fins 13 onto a plane parallel to the contact plate 312. In other words, the inner fins 11 are partially surrounded by the outer fins 13 to avoid electric field concentration caused by protrusions in the inner fins 11, thereby improving the insulation performance of the switching unit 300. In particular, for multiphase circuits (e.g., three-phase circuits), the inner fins 11 corresponding to two adjacent phases are shielded by the electric field of the corresponding outer fins 13, thereby improving the phase-to-phase insulation performance of the switching unit 300. Alternatively, the structure of the inner fins 11 may also be non-parallel. Figure 8 As shown, the upper part of the widest part in the middle of the internal fin 11 can be other shapes, such as mushroom shape or other shapes that can shield the electric field of the internal components.

[0122] Preferably, the outer periphery of the outer fin 13 has a first arc portion 17 and a second arc portion 18, with the first arc portion 17 located outside the second arc portion 18 along a first direction, forming a smooth transition between the first arc portion 17 and the second arc portion 18. This gives the outer fin 13 a smooth shape without sharp points, thus preventing electric field concentration at the tips and improving the insulation performance of the switching unit 300. More preferably, the radius of the first arc portion 17 can be larger than the radius of the second arc portion 18. Simulation analysis results show that, compared to the case where the radii of the first and second arc portions are equal, the structure proposed in this invention, where the radius of the first arc portion 17 is larger than the radius of the second arc portion 18, increases the breakdown voltage from approximately 120kV to approximately 135kV. Therefore, when the radius of the first arc portion 17 is larger than the radius of the second arc portion 18, the electric field distribution around the switching unit 300 is more uniform, further improving the insulation performance of the switching unit 300.

[0123] According to the above embodiments, the switch unit 100 proposed in this invention has good insulation and heat dissipation performance. This is particularly important for environmentally friendly switchgear, because sulfur hexafluoride gas, traditionally used for heat dissipation and insulation, has a strong greenhouse effect. Therefore, for environmental protection requirements, sulfur hexafluoride gas is replaced with dry air. Dry air has lower thermal conductivity and insulation properties than sulfur hexafluoride, thus placing higher demands on the heat dissipation and insulation performance of the switchgear. Therefore, this invention proposes a switch unit 100 that, while replacing the gas filling the switchgear with dry air to meet environmental requirements, still satisfies the insulation and heat dissipation performance requirements of the switchgear.

[0124] This document describes in detail several exemplary embodiments of the present disclosure with reference to preferred embodiments. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the concept of the present disclosure, and various technical features and structures proposed in the present disclosure can be combined without exceeding the protection scope of the present disclosure, the protection scope of the present disclosure being determined by the appended claims.

Claims

1. A switching unit, characterized by comprising: include: The stationary contact has at least one contact piece; At least one set of knife switches is movable between a closed position and an open position to contact or separate from the corresponding contact piece, so that the switching unit is in a closed state or an open state; The stationary contact further includes a heat sink, and a chamfer is provided between the heat sink and the contact plate. The heat sink is configured to dissipate the heat at the stationary contact to the outside.

2. The switching unit according to claim 1, characterized in that The heat sink is perpendicular to the contact plate.

3. The switching unit according to claim 1, characterized in that, The heat sink is positioned such that when the knife switch is in the closed position, it restricts the knife switch from rotating in the opposite direction to the open position.

4. The switching unit according to claim 1, characterized in that, It also includes a radiator that contacts the outer surface of the heat sink, so that heat at the stationary contact is transferred to the radiator via the heat sink.

5. The switching unit according to claim 4, characterized in that, The radiator includes an inner fin and two outer fins, the two outer fins being arranged on both sides of the inner fin along a first direction perpendicular to the contact plate.

6. The switching unit according to claim 5, characterized in that, The internal fins form a plurality of parallel internal grooves, which are arranged side by side along the first direction, and each internal groove extends along a second direction, which is perpendicular to the heat sink.

7. The switching unit according to claim 5, characterized in that, The outer fin has a plate-shaped fin body, which is parallel to the contact plate. The fin body has multiple parallel external grooves that extend along a closed path.

8. The switching unit according to claim 6, characterized in that, The projection of the inner fin onto the plane parallel to the contact plate lies within the projection of the outer fin onto the plane parallel to the contact plate.

9. The switching unit according to claim 8, characterized in that, The outer periphery of the outer fin has a first arc portion and a second arc portion, the first arc portion is located outside the second arc portion along the first direction, and a smooth transition is formed between the first arc portion and the second arc portion.

10. The switching unit according to claim 9, characterized in that, The radius of the first arc portion is greater than the radius of the second arc portion.

11. The switching unit according to claim 4, characterized in that, There is a gap between the heat sink and the contact plate.

12. The switching unit according to any one of claims 1 to 11, characterized in that, The stationary contact has one contact piece, which forms an L-shaped structure with the heat sink, or the stationary contact has two contact pieces, which form a U-shaped structure with the heat sink.

13. The switching unit according to any one of claims 1 to 11, characterized in that, The stationary contact also has a connecting piece, the connecting piece, the contact piece, and the heat sink are perpendicular to each other, and the connecting piece is electrically connected to the bus bushing.

14. A switch cabinet, characterized in that, The switch unit according to any one of claims 1 to 13 is arranged in the switch cabinet.

15. The switchgear according to claim 14, characterized in that, The switch cabinet is filled with dry air.

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