High voltage circuit breaker

Abstract

A high-voltage circuit breaker unit, the high-voltage circuit breaker unit includes a fixed contact assembly and a movable contact assembly, the fixed contact assembly has at least a first fixed main contact and a first fixed auxiliary contact, the movable contact assembly has at least a first movable main contact and a first movable auxiliary contact, the first movable main contact and the first movable auxiliary contact rotate from a contact closing position to a contact opening position relative to the first fixed main contact and the first fixed auxiliary contact, characterized in that during the breaking operation of the circuit breaker unit, the separation of the first movable main contact and the first fixed main contact occurs before the separation of the first movable auxiliary contact and the first fixed auxiliary contact, and is also characterized in that the relative breaking speed V1 between the first movable auxiliary contact and the first fixed auxiliary contact is greater than the relative breaking speed V2 between the first movable main contact and the first fixed main contact.

Description

Technical Field

[0001] The present invention relates to a high voltage circuit breaker, and more particularly to a contact assembly of a high voltage circuit breaker or a combined circuit breaker and earthing switch used in a high voltage metal enclosed switchgear. For the purpose of the present invention, the term "high voltage" is used to indicate an operating voltage above 1000 volts AC.

[0002] In particular, the high-voltage circuit breaker according to the invention, thanks to its innovative structure, allows optimizing the performance of the required electrical operations according to a solution that is at the same time simple, effective and compact. Background Art

[0003] It is known from the prior art that electrical operations for disconnection or for disconnection and earthing in gas-insulated switchgear can be performed by means of a translational movement of one or more movable contacts, wherein these movable contacts can be coupled / uncoupled relative to corresponding fixed contacts. A significant disadvantage of devices of known type is due to the fact that, in order to perform the various operations, such as disconnection operations on input or output lines, dedicated components are used that are structurally separate and different from each other. In this way, the number of components for implementing the various operations is high and leads to an increase in the overall size and volume of the device, with the result that an additional burden is created in terms of costs.

[0004] It is also known from the prior art that a breaking unit or a combined breaking and earthing unit can be operated by a rotary actuation device, usually a motor drive. The movable contact is usually rigidly fixed to the motor and rigidly rotates with it to perform the required breaking and / or earthing operation.

[0005] In order to withstand the arc generated during the opening / closing operation, the fixed contact assembly and the movable contact assembly are usually provided with auxiliary contacts, which are made of or contain materials with better arc resistance (such as tungsten / copper alloy). During the opening / closing operation, the current is switched to the auxiliary contacts.

[0006] In special cases, such as busbar switching operations in double busbar (DBB) air insulated switchgear (AIS), it is necessary to cope with a certain voltage difference between the two busbars due to the significant voltage drop (which is usually much larger than the voltage drop in gas insulated switchgear (GIS). In this case, there is a large arc energy, which may cause rapid ablation of the arc contact material.

[0007] Therefore, in order to ensure the normal function of the switchgear, the standard requirements for such applications (such as the IEC standard bus transfer current switching test) are particularly strict in specifying the voltage and current ratings to be applied for the bus transfer current switching test (which includes N°100 CO operation).

[0008] For example, for applications with a nominal voltage of 170 kV and a rated normal current ≥ 2000 A, the busbar switching rating is 100 V / 1600 A. In these cases, at speeds typically used for rotating contacts, the auxiliary contacts are subject to extended arc durations (e.g., arc durations > 100 ms) when opening, and significant pre-arcing occurs when closing.

[0009] This large arc energy will cause rapid ablation of arc contact materials, resulting in loss of insulation coordination. The nominal contacts will gradually be affected by the arc, thus losing the DS function and causing the busbar transfer test to fail.

[0010] In order to avoid the above problems and use a rotating DS or a combined DS / ES to pass the bus transfer test, the arc duration during breaking must be significantly shortened to an acceptable arc energy level.

[0011] Therefore, the relative breaking speed between the arcing contacts should be significantly improved, for example at least by a factor of 10. This can be achieved by a high-speed drive, but this solution will inevitably lead to an oversize of the motor drive and increase costs and technical risks (mechanical aspects, sealing aspects, etc.). Summary of the invention

[0012] Based on the above considerations, there is a need for an available technical solution for a high voltage disconnecting unit, which will be able to overcome the above limitations and problems.

[0013] Therefore, the present disclosure aims to provide a high-voltage disconnecting unit which allows to overcome at least some of the above-mentioned disadvantages.

[0014] In particular, the present invention aims to provide a high voltage circuit breaker unit which is able to withstand adverse arcing effects during opening / closing operations of the circuit breaker unit.

[0015] Furthermore, an object of the present invention is to provide a high-voltage breaking unit which is capable of ensuring appropriate arc resistance without oversizing an actuating drive of the breaking unit.

[0016] Furthermore, the present invention aims to provide a high-voltage disconnecting unit in which the erosion of the contact surfaces in the event of an arc being formed is significantly reduced.

[0017] Furthermore, it is an object of the present invention to provide a high-voltage breaking unit in which the risk of pre-striking of an arc during a making operation is significantly reduced.

[0018] In addition, the present invention aims to provide a high-voltage circuit breaker unit, which can pass the busbar switching standard test with a certain safety margin.

[0019] Furthermore, the present invention aims to provide a high voltage breaking unit, wherein the general power test performance of a rotating DS or a combined DS / ES is improved.

[0020] Furthermore, an object of the present invention is to provide a high-voltage disconnecting unit which has a compact structure with a reduced number of components, is reliable and is relatively easy to produce at competitive costs.

[0021] Therefore, the present invention relates to a high-voltage circuit breaker unit, which includes a fixed contact assembly and a movable contact assembly, wherein the fixed contact assembly has at least a first fixed main contact and a first fixed auxiliary contact, and the movable contact assembly has at least a first movable main contact and a first movable auxiliary contact, wherein the first movable main contact and the first movable auxiliary contact rotate from a contact closing position to a contact opening position relative to the first fixed main contact and the first fixed auxiliary contact. The high-voltage circuit breaker unit disclosed in the present invention is characterized in that, during the breaking operation of the circuit breaker unit, the separation of the first movable main contact from the first fixed main contact occurs before the separation of the first movable auxiliary contact from the first fixed auxiliary contact, and is also characterized in that the relative breaking speed V1 between the first movable auxiliary contact and the first fixed auxiliary contact is greater than the relative breaking speed V2 between the first movable main contact and the first fixed main contact.

[0022] As better explained in the following description, due to the specific structure of the high voltage circuit breaker unit of the present invention, especially the specific structure of the fixed contact assembly and the movable contact assembly, the above problems can be avoided or at least greatly reduced.

[0023] In fact, in the high-voltage circuit breaker unit of the present invention, the separation of the movable main contact and the movable auxiliary contact from the corresponding fixed main contact and the fixed auxiliary contact occurs at different times and at different speeds. Relative to the separation of the main contact, the separation of the auxiliary contact occurs later and at a faster speed.

[0024] In this way, the arc duration is significantly reduced without oversizing the actuating drive of the movable contact assembly. In fact, although the speed V2 of the first movable main contact can be kept at a relatively low value, for example <1.5 rad / s, the speed V1 of the first movable auxiliary contact can be an order of magnitude higher than V2, or even more. In this way, the arc duration can be greatly reduced.

[0025] As better illustrated in the description below, in a typical embodiment of a high-voltage circuit breaker unit according to the present invention, the movable contact assembly may advantageously include an elastic device, and when the first movable auxiliary contact is separated from the corresponding first fixed auxiliary contact, the elastic device acts on the first movable auxiliary contact with a snapping action, thereby giving the first movable auxiliary contact the breaking speed V2.

[0026] In this case, said resilient means may conveniently comprise spring means, such as one or more springs appropriately positioned to impart said snap action to said first movable auxiliary contact.

[0027] In an advantageous embodiment of the high-voltage disconnecting unit according to the invention, preferably, the first movable main contact rotates about a first rotation axis and the first movable auxiliary contact rotates about a second rotation axis which is different from and separate from the first rotation axis.

[0028] In fact, in the high-voltage circuit breaker unit of the present invention, the breaking speed V1 is the rotational angular velocity of the first movable auxiliary contact around the second rotation axis, and the breaking speed V2 is the rotational angular velocity of the first movable main contact around the first rotation axis.

[0029] In this case, in a more preferred embodiment of the high-voltage circuit breaker unit, the second rotation axis is advantageously pivotably fixed to the first movable main contact, so that the relative position of the second rotation axis relative to the first fixed main contact and the first fixed auxiliary contact changes during the rotation of the first movable main contact.

[0030] In fact, according to this embodiment, during the circuit breaking operation of the high-voltage circuit breaker unit, the second rotation axis of the first movable auxiliary contact is not fixed relative to the fixed contact assembly but changes. In particular, as better explained below, during at least one phase of the circuit breaking operation, the distance between the second rotation axis of the first movable auxiliary contact and the first fixed main contact and the first fixed auxiliary contact increases.

[0031] In a specific embodiment of the currently disclosed high-voltage circuit breaker unit, the first movable main contact includes a first contact arm and a second contact arm that are parallel to each other and spaced apart from each other along a first rotation axis, and the first movable auxiliary contact is located between the first contact arm and the second contact arm.

[0032] A typical embodiment of the high-voltage circuit breaker unit is characterized in that the fixed contact assembly includes a fixed contact body. The first fixed main contact advantageously includes a first contact surface and a second contact surface located on opposite sides of the fixed contact body. Accordingly, the first fixed auxiliary contact preferably includes a third contact surface located on the bottom portion of the fixed contact body. For the purpose of the present invention, the term "bottom portion" refers to the portion of the fixed contact body that is closest to the first movable auxiliary contact.

[0033] Furthermore, the first contact surface and the second contact surface are substantially parallel to each other, and the third contact surface is substantially perpendicular to the first contact surface and the second contact surface.

[0034] In fact, in this highly preferred embodiment of the invention, the fixed contact assembly is formed by a single fixed contact body, which has two parallel surfaces on first and second opposite faces, thereby forming the first contact surface and the second contact surface, and has a third surface on a third face perpendicular to the first and second opposite faces, thereby forming the third contact surface.

[0035] In this case, according to a preferred embodiment of the high-voltage circuit breaker unit disclosed herein, the first contact arm and the second contact arm of the first movable main contact advantageously include contact strips on their respective facing surfaces, and the contact strips are operably connectable to the first contact surface and the second contact surface of the fixed contact body, as better described below.

[0036] Accordingly, the first movable auxiliary contact advantageously comprises: a contact support portion rigidly fixed on the second rotating shaft and a contact head at the end of the contact support portion, the contact head being capable of being operably connected to the third contact surface of the fixed contact body, as better described below.

[0037] In an embodiment of the high-voltage circuit breaker unit disclosed herein, the elastic device preferably includes a first torsion spring and a second torsion spring, and the first torsion spring and the second torsion spring are coaxially installed on the second rotating axis between the contact support portion and the first contact arm and between the contact support portion and the second contact arm, respectively.

[0038] According to the present invention, in a typical operating situation of the high-voltage circuit breaker unit, in the closed position of the circuit breaker unit, the first movable main contact is coupled to the first fixed main contact, while the first movable auxiliary contact is decoupled from the first fixed auxiliary contact. Therefore, in the closed position, the current flows only through the first fixed main contact and the first movable main contact. Alternatively, in the closed position, both the first movable main contact and the first movable auxiliary contact engage with the corresponding fixed contact.

[0039] Subsequently, the breaking operation of the circuit breaker unit generally includes a first step in which the first movable main contact rotates and remains in contact with the first fixed main contact, while the first movable auxiliary contact is in contact with the first fixed auxiliary contact. During this stage, current flows through the first fixed main contact and the first movable main contact, as well as the first fixed auxiliary contact and the first movable auxiliary contact. When both the first movable main contact and the first movable auxiliary contact are engaged with the corresponding fixed contacts in the closed position, the first step does not exist.

[0040] In the second step of the breaking operation of the circuit breaker unit, the first movable main contact continues to rotate and is disconnected from the first fixed main contact at the breaking speed V2, while the first movable auxiliary contact bends backward in a direction opposite to the rotation direction of the first movable main contact and slides on the first fixed auxiliary contact to maintain electrical contact with the first fixed auxiliary contact. Therefore, during this stage, the current path is switched from the main contact to the auxiliary contact.

[0041] Subsequently, in the third step of the breaking operation of the circuit breaker unit, the first movable main contact continues to rotate, while the first movable auxiliary contact moves away from the first fixed auxiliary contact at the breaking speed V1. This is the stage where the actual separation between the movable contact assembly and the fixed contact assembly occurs and an arc is formed. As mentioned above, since the breaking speed V1 can be very high relative to the conventional breaking speed (i.e., relative to the breaking speed V2 usually given to the main movable contact by the driver), the arc duration can be greatly reduced, thereby minimizing the above-mentioned adverse effects.

[0042] Finally, in the opening position of the circuit breaker unit, both the first movable main contact and the first movable auxiliary contact are decoupled from the corresponding first fixed main contact and first fixed auxiliary contact.

[0043] In a preferred embodiment of the currently disclosed high-voltage circuit breaker unit, in the third step, the first movable auxiliary contact preferably moves away from the first fixed auxiliary contact by rotating in the same direction as the first movable main contact under the action of the elastic device.

[0044] As better explained below, in a preferred embodiment of the present invention, during one stage of the breaking operation, the first movable auxiliary contact is bent backward in a direction opposite to the rotation direction of the first movable main contact due to mechanical interference with the surface of the first fixed auxiliary contact, thereby loading the elastic device (e.g. spring device).

[0045] Subsequently, in the subsequent stage of the breaking operation, the mechanical interference between the first movable auxiliary contact and the first fixed auxiliary contact stops, and the first movable auxiliary contact is free to move rapidly along the rotation direction of the first movable main contact under the action of the elastic device, thereby achieving separation from the corresponding first fixed auxiliary contact.

[0046] In other words, in a more preferred embodiment of the invention, in this subsequent operation phase, the force exerted by the elastic means on the first movable auxiliary contact overcomes the mechanical resistance between the first movable auxiliary contact and the first fixed auxiliary contact. As a result, the first movable auxiliary contact is free to quickly snap away from the first fixed auxiliary contact by rotating counterclockwise at the breaking speed V1, which is substantially given by the rotational angular velocity of the first movable auxiliary contact around its rotation axis.

[0047] According to an embodiment of the high-voltage breaking unit of the present invention, the breaking unit may include at least a second fixed contact assembly.

[0048] Preferably, the second fixed contact assembly is conveniently spaced apart from the first fixed contact assembly and, in one embodiment, is located in the rotation plane of the first movable main contact. In fact, according to this embodiment, the first movable main contact can be connected to either the first fixed contact assembly or the second fixed contact assembly by rotating through successive contact positions. According to a preferred alternative embodiment, the second fixed contact assembly is located outside the rotation plane of the first movable main contact, and the movable contact assembly is conveniently provided with a second movable main contact and a second movable auxiliary contact that can be connected / disconnected with the second fixed contact in a manner similar to the first fixed contact and the first movable contact.

[0049] In another preferred embodiment of the high-voltage disconnecting unit according to the present invention, the disconnecting unit may include a third fixed contact assembly, the third fixed contact assembly is spaced apart from the first fixed contact assembly and the second fixed contact assembly, and is located in the rotation plane of the first movable main contact. One of the second fixed contact assembly and the third fixed contact assembly is at ground potential. In this way, a typical combined disconnecting and grounding operation of a high-voltage switchgear can be implemented.

[0050] In particular, if the fixed contacts at earth potential are provided with corresponding fixed auxiliary contacts, the more stringent ratings of the inductive current switching test specified in Annex C of IEC 62271-102 can be achieved, which would otherwise require the use of much more expensive fast earthing circuit breakers.

[0051] A high-voltage switchgear comprising the disclosed breaking unit is also part of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Other features and advantages of the present invention will become more apparent from the description of a preferred but not exclusive embodiment of a high voltage disconnecting unit according to the present invention, which is shown by way of example in the accompanying drawings, in which:

[0053] Figure 1 is a three-dimensional diagram of an embodiment of a high-voltage circuit breaker unit according to the present invention, wherein the high-voltage circuit breaker unit is in a contact closing position;

[0054] Figure 2 is a three-dimensional diagram of an embodiment of a high-voltage circuit breaker unit according to the present invention, wherein the high-voltage circuit breaker unit is in a contact-breaking position;

[0055] Figure 3 is a more detailed stereoscopic view of an embodiment of a high-voltage circuit breaker unit according to the present invention, wherein the high-voltage circuit breaker unit is in a contact-opening position;

[0056] Figure 4 is a second stereoscopic view of an embodiment of a high-voltage circuit breaker unit according to the present invention, wherein the high-voltage circuit breaker unit is in a contact closing position;

[0057] Figure 5 is a perspective view of a first stage of a breaking operation of a high-voltage circuit breaker unit according to the present invention;

[0058] Figure 6 is a perspective view of a second stage of a breaking operation of a high-voltage circuit breaker unit according to the present invention;

[0059] Figure 7 is a perspective view of a third stage of a breaking operation of a high-voltage circuit breaker unit according to the present invention;

[0060] Figure 8 It is a second stereoscopic view of an embodiment of a high-voltage circuit breaker unit according to the present invention, wherein the high-voltage circuit breaker unit is in a contact-breaking position. DETAILED DESCRIPTION

[0061] With reference to the drawings, the high-voltage breaking unit of the present invention, indicated by reference numeral 1 , in its more general definition comprises a fixed contact assembly 2 having at least a first fixed main contact 21 and a first fixed auxiliary contact 22 .

[0062] The circuit breaker unit 1 further comprises a movable contact assembly 3, which has at least a first movable main contact 31 and a first movable auxiliary contact 32, and the first movable main contact 31 and the first movable auxiliary contact 32 are rotatable from a contact closing position to a contact opening position relative to the first fixed main contact 21 and the first fixed auxiliary contact 22. According to known embodiments, the first movable main contact 31 can be operably connected to a motor driver, such as an electrically controlled rotary motor, which imparts a rotational movement to the first movable main contact 31 to implement a desired opening or closing operation.

[0063] One of the notable features of the circuit-breaking unit 1 of the present invention is given by the fact that during the breaking operation of the circuit-breaking unit 1, the separation of the first movable main contact 31 from the first fixed main contact 21 occurs before the separation of the first movable auxiliary contact 32 from the corresponding first fixed auxiliary contact 22.

[0064] Furthermore, the circuit breaker unit 1 of the present invention is characterized in that a relative breaking speed V1 between the first movable auxiliary contact 32 and the first fixed auxiliary contact 22 is greater than a relative breaking speed V2 between the first movable main contact 31 and the first fixed main contact 21 .

[0065] In other words, in the breaking unit 1 of the present invention, the separation between the main contacts 21 and 31 occurs at different times and at different speeds relative to the separation between the auxiliary contacts 32 and 22 .

[0066] In a typical embodiment of the high-voltage circuit breaker unit 1, the movable contact assembly 3 further comprises an elastic device 4, which acts on the first movable auxiliary contact 32 with a snap action, and the snap action imparts the breaking speed V2 to the first movable auxiliary contact 32. In other words, when the first movable main contact 31 moves at a speed V2 by, for example, a motor drive, the breaking operation of the first movable auxiliary contact 32 is actuated by the elastic device 4 through a snap action at a speed V1, which is greater than the speed V2 of the first movable main contact 31.

[0067] Preferably, said elastic means 4 may conveniently comprise spring means, such as one or more torsion springs appropriately positioned.

[0068] In the illustrated embodiment, the opening / closing operation of the high-voltage circuit breaker unit 1 occurs by the rotation of the first movable main contact 31 about the first rotation axis 310 and the rotation of the first movable auxiliary contact 32 about the second rotation axis 320 .

[0069] Special reference Figures 1 to 3The position of the first rotating shaft 310 is fixed relative to the first fixed main contact 21 and the first fixed auxiliary contact 22, while the second rotating shaft 320 is pivotally fixed on the first movable main contact 31, especially in its eccentric position relative to the first rotating shaft 310.

[0070] In fact, the breaking speed V1 is given by the rotational angular velocity of the first movable auxiliary contact 32 around the second rotation axis 320 , while the breaking speed V2 is given by the rotational angular velocity of the first movable main contact 31 around the first rotation axis 310 .

[0071] Therefore, during the rotation of the first movable main contact 31, the relative position of the second rotation axis 320 with respect to the first fixed main contact 21 and the first fixed auxiliary contact 22 changes. Figure 1 In the closed position, the second rotating shaft 320 is located between the first rotating shaft 310 and the fixed main contact 21 and the fixed auxiliary contact 22, and Figure 2 and Figure 3 When the second rotating shaft 320 is in the disconnecting position, it moves counterclockwise, and the distance between the second rotating shaft 320 and the fixed main contact 21 and the fixed auxiliary contact 22 increases.

[0072] In the embodiment of the high voltage circuit breaker unit 1 shown in the drawings, the first movable main contact 31 comprises a first contact arm 311 and a second contact arm 312 which are parallel to each other. Moreover, the first contact arm 311 and the second contact arm 312 are spaced apart from each other along the first rotation axis 310, leaving a space therebetween.

[0073] In this way, the first movable auxiliary contact 32 can be conveniently located in the space between the first contact arm 311 and the second contact arm 312 , thereby obtaining a very compact structure of the movable contact assembly 3 .

[0074] As shown in the embodiment of the drawings, the fixed contact assembly 2 includes a fixed contact body 20 having an elongated shape, which protrudes toward the movable contact assembly 3 .

[0075] The first fixed main contact 21 includes a first contact surface 211 and a second contact surface 212 located on opposite sides of the slender fixed contact body 20, and the first fixed auxiliary contact 22 includes a third contact surface 223 located on the bottom portion of the fixed contact body 20 (i.e., at the end of the fixed contact body 20 close to the movable contact assembly 3).

[0076] In fact, as clearly shown in the drawings, the first contact surface 211 and the second contact surface 212 are substantially parallel to each other, while the third contact surface 223 is substantially perpendicular to the first contact surface 211 and the second contact surface 212 .

[0077] Therefore, from a construction point of view, the fixed contact assembly 2 can be conveniently formed by a single fixed contact body 20, which has two parallel surfaces 211 and 212 on first and second opposite faces, thereby forming the first contact surface and the second contact surface. The fixed contact body 20 is also provided with a third surface 223 on a third face perpendicular to the first and second opposite faces of the fixed contact body 20, thereby forming the third contact surface. In this way, the overall design of the fixed contact assembly 2 can have a very compact design and can be manufactured very easily.

[0078] Special References Figure 2 and Figure 3 In the illustrated embodiment, the first contact arm 311 and the second contact arm 312 of the first movable main contact 31 include contact strips 350 on their respective facing surfaces (ie, the surfaces of the first contact arm 311 and the second contact arm 312 facing each other).

[0079] The contact strip 350 is operably coupled to the first contact surface 211 and the second contact surface 212 of the fixed contact body 20 , and provides a nominal current path when the breaking unit 1 is in the closed position.

[0080] The first movable auxiliary contact 32 includes a contact support portion 321 and a contact head portion 322 . The contact support portion 321 is in the form of an elongated body and has a first end rigidly fixed on the second rotating shaft 320 . The contact head portion 322 is located at the second end of the contact support portion 321 .

[0081] The contact head 322 is operably coupled to the third contact surface 223 of the fixed contact body 20 and provides a switching current path during a phase of a breaking operation of the breaking unit 1 .

[0082] In one embodiment of the high-voltage circuit breaker unit 1, the elastic device 4 includes a first torsion spring 41 and a second torsion spring 42, and the first torsion spring 41 and the second torsion spring 42 are coaxially installed on the second rotating shaft 320 between the contact support portion 321 and the first contact arm 311 and between the contact support portion 321 and the second contact arm 312, respectively.

[0083] Refer to the attached Figures 4 to 8 , the breaking operation of the high-voltage circuit breaker unit 1 of the present invention can be described as follows.

[0084] refer to Figure 4In the closed position of the circuit breaker unit 1 , the first movable main contact 31 is connected to the first fixed main contact 21 to provide a nominal current path, while the first movable auxiliary contact 32 is disconnected from the first fixed auxiliary contact 22 .

[0085] Then, refer to Figure 5 In the first step of the breaking operation, the first movable main contact 31 rotates, for example, counterclockwise, and remains in contact with the first fixed main contact 21, while the first movable auxiliary contact 32 is in contact with the first fixed auxiliary contact 22. At this stage, current can flow through the main contact 21, 31 system and the auxiliary contact 22, 32 system, and the current intensity depends on the contact resistance of the main contact 21, 31 system and the auxiliary contact 22, 32 system.

[0086] As mentioned above, in a more general embodiment of the high voltage breaking unit 1, in the closed position, both the first movable main contact 31 and the first movable auxiliary contact 32 engage with the corresponding fixed main contact 21 and the fixed auxiliary contact 22, in which case the above-mentioned first step does not exist.

[0087] In the second step of the breaking operation, Figure 6 As shown, the first movable main contact 31 continues to rotate counterclockwise and disconnects from the first fixed main contact 21 at the breaking speed V2 (the main contact is broken), and at the same time, the first movable auxiliary contact 32 bends backward clockwise in the direction opposite to the rotation direction of the first movable main contact 31 and slides on the first fixed auxiliary contact 21, thereby maintaining electrical contact therewith. Therefore, during this stage, the current path is switched from the main contact system to the auxiliary contact system. At the same time, the mechanical interference between the first movable auxiliary contact 32 and the first fixed auxiliary contact 22 (which forces the first movable auxiliary contact 32 to bend backward and rotate clockwise) causes the elastic device 4 to be loaded.

[0088] Subsequently, the first movable main contact 31 continues to rotate counterclockwise, and the first movable auxiliary contact 32 slides on the first fixed auxiliary contact 21, while its rotation axis 320 moves away from the fixed contact assembly until it reaches Figure 7 location.

[0089] In this position, the force applied by the elastic means 4 overcomes the mechanical resistance between the first movable auxiliary contact 32 and the first fixed auxiliary contact 22. Therefore, the first movable auxiliary contact 32 is free to quickly snap away from the first fixed auxiliary contact by rotating counterclockwise at the breaking speed V1, which is substantially given by the rotational angular speed of the first movable auxiliary contact 32 around its rotation axis 320.

[0090] Finally, reference Figure 8In the disconnecting position, the first movable main contact 31 and the first movable auxiliary contact 32 are disconnected from the corresponding first fixed main contact 21 and the first fixed auxiliary contact 22 .

[0091] The breaking operation of the high-voltage circuit breaker unit 1 has been described with reference to the counterclockwise movement of the first movable main contact 31 and the initial clockwise movement of the first movable auxiliary contact 32 and the subsequent counterclockwise snap action of the first movable auxiliary contact 32. Obviously, the operation can be performed in a similar manner by rotating the first movable main contact 31 clockwise and rotating the first movable auxiliary contact 32 first counterclockwise and then clockwise.

[0092] According to a specific embodiment of the high-voltage breaking unit 1 not shown in the drawings, the breaking unit 1 may comprise at least a second fixed contact assembly.

[0093] The second fixed contact assembly is conveniently spaced apart from the first fixed contact assembly 2 and is located in the rotation plane of the first movable main contact 31. In fact, according to this embodiment, the first movable main contact 31 can be coupled with either the first fixed contact assembly 2 or the second fixed contact assembly by rotating through successive contact positions.

[0094] In addition, the circuit breaker unit 1 may include a third fixed contact assembly, which is spaced apart from the first fixed contact assembly 2 and the second fixed contact assembly and is located in the rotation plane of the first movable main contact 31, and one of the second fixed contact assembly 2 and the third fixed contact assembly is at ground potential. In this way, a typical combined circuit breaking and grounding operation of a high-voltage switchgear can be implemented.

[0095] It can be clearly seen from the above description that the currently disclosed high-voltage circuit breaker unit completely solves the highlighted technical problems of the circuit breaker units of the prior art.

[0096] In particular, the high separation speed between the auxiliary fixed contact and the main contact that can be achieved by the invention allows to reduce the arc duration relative to conventional circuit-breaking units. As a result, the ablation of the contact surface in the event of an arc is significantly reduced. This has a very positive effect not only on the operating life of the circuit-breaking unit, but also on the ability of the circuit-breaking unit to pass the busbar switching standard test with a certain safety margin and more generally improve the power test performance.

[0097] Furthermore, the erosion of the contacts is significantly reduced due to less arc exposure, and thus the risk of pre-arcing during the closing operation is also significantly reduced, thereby greatly improving the performance of the high-voltage circuit breaker unit during the closing operation.

[0098] It is also worth noting that the structure of the circuit breaker unit is very simple and the number of components is reduced, thereby minimizing manufacturing and maintenance costs. In addition, the structure is extremely compact, which can allow for a significant optimization of the space and volume within the circuit breaker unit.

[0099] The high-voltage disconnecting unit thus conceived can be subjected to numerous modifications, all of which fall within the scope of the appended claims.In practice, the materials used as well as the possible dimensions and shapes may be any, according to requirements and the state of the art.

Claims

1. A high-voltage circuit breaker unit (1), comprising a fixed contact assembly (2) and a movable contact assembly (3), wherein the fixed contact assembly (2) has at least a first fixed main contact (21) and a first fixed auxiliary contact (22), and the movable contact assembly (3) has at least a first movable main contact (31) and a first movable auxiliary contact (32), wherein the first movable main contact (31) and the first movable auxiliary contact (32) rotate relative to the first fixed main contact (21) and the first fixed auxiliary contact (22) from a contact closing position to a contact opening position, characterized in that: During the breaking operation of the high-voltage circuit breaker unit (1), the separation of the first movable main contact (31) from the first fixed main contact (21) occurs before the separation of the first movable auxiliary contact (32) from the first fixed auxiliary contact (22), and the feature is that the relative breaking speed V1 between the first movable auxiliary contact (32) and the first fixed auxiliary contact (22) is greater than the relative breaking speed V2 between the first movable main contact (31) and the first fixed main contact (21), and the fixed contact assembly (2) comprises a fixed contact body (20), the first fixed main contact (21) comprises a first contact surface (211) and a first contact surface (212) located on opposite sides of the fixed contact body (20); The first movable auxiliary contact (32) comprises a third contact surface (223) located on the bottom part of the fixed contact body (20), the first movable auxiliary contact (32) slides on the third contact surface (223) of the first fixed auxiliary contact (22), the first movable main contact (31) rotates around a first rotation axis (310), and the first movable auxiliary contact (32) rotates around a second rotation axis (320), the breaking speed V1 is the rotation angular velocity of the first movable auxiliary contact (32) around the second rotation axis (320), and the breaking speed V2 is the rotation angular velocity of the first movable main contact (31) around the first rotation axis (310).

2. The high-voltage circuit breaker unit (1) according to claim 1, characterized in that: The movable contact assembly (3) comprises an elastic device (4), wherein the elastic device (4) acts on the first movable auxiliary contact (32) in a snap-action action, and the snap-action action imparts the first movable auxiliary contact (32) with the breaking speed V2.

3. The high-voltage circuit breaker unit (1) according to claim 2, characterized in that: The elastic device (4) comprises a spring device.

4. The high-voltage circuit breaker unit (1) according to claim 1, characterized in that: The second rotating shaft (320) is pivotally fixed to the first movable main contact (31), and the relative position of the second rotating shaft (320) relative to the first fixed main contact (21) and the first fixed auxiliary contact (22) changes during the rotation of the first movable main contact (31).

5. The high voltage breaking unit (1) according to any one of claims 1 to 3, characterized in that: The first movable main contact (31) comprises a first contact arm (311) and a second contact arm (312) which are parallel to each other and spaced apart from each other along a first rotation axis (310), and the first movable auxiliary contact (32) is located between the first contact arm (311) and the second contact arm (312).

6. The high-voltage circuit breaker unit (1) according to claim 5, characterized in that: The first contact surface (211) and the second contact surface (212) are substantially parallel to each other, and the third contact surface (223) is substantially perpendicular to the first contact surface (211) and the second contact surface (212).

7. The high-voltage circuit breaker unit (1) according to claim 6, characterized in that: The first contact arm (311) and the second contact arm (312) of the first movable main contact (31) include a contact strip (350) on the surfaces of the first contact arm (311) and the second contact arm (312) facing each other, and the contact strip (350) can be operably connected to the first contact surface (211) and the second contact surface (212) of the fixed contact body (20), and the first movable auxiliary contact (32) includes a contact support portion (321) rigidly fixed on the second rotating shaft (320) and a contact head (322) at the end of the contact support portion (321), and the contact head (322) can be operably connected to the third contact surface (223) of the fixed contact body (20).

8. The high-voltage disconnecting unit (1) according to claim 7, characterized in that: The movable contact assembly (3) includes an elastic device (4), and the elastic device (4) acts on the first movable auxiliary contact (32) with a quick action, and the quick action gives the first movable auxiliary contact (32) the breaking speed V2, and the elastic device (4) includes a first torsion spring (41) and a second torsion spring (42), and the first torsion spring (41) and the second torsion spring (42) are coaxially installed on the second rotating shaft (320) between the contact support part (321) and the first contact arm (311) and between the contact support part (321) and the second contact arm (312), respectively.

9. The high-voltage breaking unit (1) according to any one of claims 1 to 3, characterized in that: In the closed position of the high-voltage circuit breaker unit (1), the first movable main contact (31) is connected to the first fixed main contact (21), and the first movable auxiliary contact (32) is disconnected from the first fixed auxiliary contact (22), and is characterized in that the breaking operation of the high-voltage circuit breaker unit (1) includes a first step, a second step, a third step, and a fourth step. In the first step, the first movable main contact (31) rotates and maintains contact with the first fixed main contact (21), and the first movable auxiliary contact (32) is in contact with the first fixed auxiliary contact (22). In the second step, the first movable main contact (31) continues to rotate and moves at the breaking speed V2. The first movable auxiliary contact (32) is disconnected from the first fixed main contact (21), and the first movable auxiliary contact (32) is bent backward in a direction opposite to the rotation direction of the first movable main contact (31) and slides on the first fixed auxiliary contact (22) so as to maintain electrical contact with the first fixed auxiliary contact. In the third step, the first movable main contact (31) continues to rotate, and the first movable auxiliary contact (32) moves away from the first fixed auxiliary contact (22) at the breaking speed V1. In the fourth step, both the first movable main contact (31) and the first movable auxiliary contact (32) are disconnected from the corresponding first fixed main contact (21) and the first fixed auxiliary contact (22).

10. The high-voltage disconnecting unit (1) according to claim 9, characterized in that: The movable contact assembly (3) comprises an elastic device (4), wherein the elastic device (4) acts on the first movable auxiliary contact (32) in a snap-action manner, wherein the snap-action manner imparts the first movable auxiliary contact (32) with the breaking speed V2. In the third step, the first movable auxiliary contact (32) moves away from the first fixed auxiliary contact (22) by rotating in the same direction as the first movable main contact (31) under the action of the elastic device (4).

11. The high voltage breaking unit (1) according to any one of claims 1 to 3, characterized in that: The high-voltage circuit breaker unit (1) comprises at least a second fixed contact assembly, which is spaced apart from the fixed contact assembly (2).

12. The high voltage circuit breaker unit according to claim 11, characterized in that: The high-voltage circuit breaker unit comprises a third fixed contact assembly, the third fixed contact assembly is spaced apart from the fixed contact assembly (2) and the second fixed contact assembly, and one of the second fixed contact assembly and the third fixed contact assembly is at ground potential.

13. The high voltage breaking unit according to claim 12, characterized in that: The movable contact assembly (3) is provided with a second movable main contact and a second movable auxiliary contact capable of being coupled to / disconnected from the second fixed contact assembly and / or the third fixed contact assembly.

14. A high-voltage switchgear, comprising a high-voltage disconnecting unit (1) according to any one of claims 1 to 13.

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