Switching device for electrical system

Abstract

The embodiment of the invention relates to a switching device for an electrical system. A low voltage switchgear comprising a switching device having one or more switching poles, each switching pole comprising: a first terminal and a second terminal coupleable with a corresponding wire conductor of an electrical wire; a fixed contact assembly including a plurality of fixed electrical contacts electrically connected to the first terminal and including one or more first fixed contacts and one or more second fixed contacts electrically insulated from the first fixed contacts; and a movable contact assembly including a plurality of movable electrical contacts electrically connected to the second terminal and including one or more first movable contacts and one or more second movable contacts. For each switching pole of the switching device, the switching apparatus includes a current limiter electrically connected in series with the second fixed contact and the first terminal of the switching pole. The current limiter is configured to limit or cut off the current during a turn-off manipulation of the switching device.

Description

Technical Field

[0001] This invention relates to a switchgear for use in electrical systems, preferably low-voltage electrical systems. Background Technology

[0002] Low-voltage switchgear (such as circuit breakers, disconnectors, contactors, etc.) includes one or more switch poles, each switch pole including one or more fixed contacts and movable contacts that can be connected and disconnected from each other.

[0003] As is well known, during the disconnection operation of a switching device, when the switch electrodes are separated, especially under stress conditions (e.g., in the presence of overload current or short-circuit current), an electric arc may occur between the electrical contacts.

[0004] To interrupt the current flowing along the switching poles, such arcing must be extinguished as quickly as possible. Therefore, for each switching pole, the switching device typically includes an arc-extinguishing chamber, comprising a suitable arc-extinguishing element positioned near the electrical contacts and designed to interrupt any arcing that may occur between the contacts. Unfortunately, the arc-extinguishing effect exerted by the arc-extinguishing element is not always uniform and effective, which can adversely affect the lifespan of the arc-extinguishing chamber itself and cause premature functional decay, thus significantly limiting the overall performance of the switching device.

[0005] Furthermore, it has been found that electric arcs can sometimes strike other conductive parts of the switching electrode, located outside the arc-extinguishing chamber of the switching electrode. Components of the switching device potentially affected by these arcs can suffer severe damage because they are not typically designed to withstand high electrical and thermal stresses. These inconveniences become even more pronounced in modern distribution networks where switching devices are often operated at relatively high voltages (e.g., up to 2.0–2.5 kV AC or DC). Therefore, during the disconnection operation of the switching device, high-power arcs can occur between the electrical contacts in the disconnected state.

[0006] In the existing technology, there is a great need for innovative solutions to overcome or alleviate the above problems. Summary of the Invention

[0007] This need is met by providing a switching device according to claim 1 and related dependent claims.

[0008] The switching device according to the present invention includes a switching device having one or more switching poles.

[0009] Each switch pole includes a first terminal and a second terminal, which are configured to be connected to the corresponding conductor of the wire.

[0010] Each switch pole includes a fixed contact assembly comprising a plurality of fixed electrical contacts electrically connected to the first pole, the fixed electrical contacts including one or more first fixed contacts and one or more second fixed contacts electrically insulated from the first fixed contacts.

[0011] Each switch pole includes a movable contact assembly comprising a plurality of movable electrical contacts electrically connected to the second pole, the movable electrical contacts including one or more first movable contacts and one or more second movable contacts.

[0012] The movable contact assembly of each switch pole is reversibly movable about a rotation axis, such that when the movable contact assembly moves about the rotation axis, the first movable contact can be connected or disconnected from the first fixed contact, and the second movable contact can be connected or disconnected from the second fixed contact.

[0013] The switching device according to the invention includes a current limiter for each switching pole of the switching device.

[0014] Each current limiter is electrically connected in series with the second fixed contact and the first terminal of the corresponding switching pole.

[0015] The current limiter is configured to, during the disconnection operation of the switching device, limit or disconnect the current flowing along a series circuit comprising at least the second fixed contact, the current limiter, and the first terminal when the first movable electrical contact of the movable contact assembly is decoupled from the first fixed contact of the fixed contact assembly.

[0016] The movable contact assembly of each switch electrode can reversibly move between a first position and a second position about the rotation axis, the first position corresponding to the closed state of the switch electrode and the second position corresponding to the open state of the switch electrode.

[0017] When the movable contact assembly is in the first position, the first movable contact is connected to the first fixed contact, and the second movable contact is disconnected from the second fixed contact.

[0018] When the movable contact assembly is in the second position, the first movable contact is decoupled from the first fixed contact, and the second movable contact is decoupled from the second fixed contact.

[0019] During the disconnection operation of the switching device, the movable contact assembly moves from the first position to a first intermediate position, in which the first movable contact is connected to the first fixed contact, and the second movable contact is connected to the second fixed contact.

[0020] The movable contact assembly then moves from the first intermediate position to a second intermediate position, in which the first movable contact is decoupled from the first fixed contact, and the second movable contact is connected to the second fixed contact.

[0021] The movable contact assembly then moves from the second intermediate position to the second position, where the second movable contact is also decoupled from the second fixed contact. When the movable contact assembly moves from the second intermediate position to the second position, the second movable contact is decoupled from the second fixed contact.

[0022] The current limiter electrically connected to the switch electrode is configured to limit or break the current flowing along the series circuit comprising at least the second fixed contact, the current limiter, and the first terminal when the movable contact assembly reaches the second intermediate position and when the movable contact assembly moves from the second intermediate position to the second position.

[0023] According to some embodiments, the switching device of the present invention includes an electromechanical auxiliary switching device electrically connected to the switching electrode of the switching device. Each current limiter of the switching device is formed by the switching electrode of the auxiliary switching device.

[0024] According to other embodiments, each current limiter of the switching device includes an electromechanical auxiliary switching device electrically connected to a corresponding switch electrode of the switching device. Preferably, the auxiliary switching device has a plurality of switch electrodes connected in series.

[0025] According to other embodiments, each current limiter of the switching device includes a semiconductor-based solid-state switching circuit electrically connected to the corresponding switching electrode of the switching device.

[0026] According to other embodiments, each current limiter of the switching device includes a fuse circuit electrically connected to the corresponding switch electrode of the switching device.

[0027] According to other embodiments, each current limiter of the switching device includes a resistor circuit electrically connected to the corresponding switch electrode of the switching device.

[0028] According to other embodiments, each current limiter of the switching device includes a resonant circuit electrically connected to the corresponding switch electrode of the switching device.

[0029] According to other embodiments, each current limiter of the switching device includes a hybrid switching circuit electrically connected to a corresponding switch electrode of the switching device. This hybrid switching circuit includes at least electromechanical switching devices and at least solid-state switching circuits combined with each other.

[0030] According to some embodiments of the present invention, for each switching pole of the switching device, the switching device includes a magnetic field generating device, which includes a first coil conductor and a second coil conductor wound around a winding axis parallel to the rotation axis of the movable contact assembly of the switching pole.

[0031] The first coil conductor and the second coil conductor are spaced apart from each other along the winding axis and are connected in series with the second fixed contact of the switch pole, the current limiter, and the first terminal of the switch pole.

[0032] A current limiter electrically connected to the switch pole is configured to, during the disconnection operation of the switching device, when the first movable electrical contact is disengaged from the first fixed contact, more specifically, when the movable contact assembly of the pole reaches the second intermediate position and moves from the second intermediate position to the second position, limit or break the current flowing along the series circuit comprising at least the second fixed contact, the first coil conductor, the current limiter, the second coil conductor, and the first pole. Attached Figure Description

[0033] Further features and advantages of the invention will become apparent from the description of preferred, but not exclusive, embodiments of the switching poles according to the invention, which are illustrated by way of example in the accompanying drawings, wherein:

[0034] Figure 1 A schematic diagram of an embodiment of the switching device according to the present invention is shown;

[0035] Figure 2 A schematic diagram of another embodiment of the switching device according to the present invention is shown;

[0036] Figures 3 to 5 It shows Figures 1 to 2 A schematic diagram of the electrodes of the switching device included in the switching equipment;

[0037] Figure 6 It shows Figure 1-Figure 2 A schematic circuit diagram of the general electrical phase of the switching equipment in the circuit;

[0038] Figure 7 It shows Figure 1 A schematic circuit diagram of a variant of the switching device for a general electrical phase;

[0039] Figure 8 It shows Figure 2 A schematic circuit diagram of a variant of a switching device for a general electrical phase;

[0040] Figures 9 to 18It is shown Figures 1 to 2 A schematic diagram of the operation of the switching equipment during the disconnection operation of the switching device;

[0041] Figure 19 A schematic circuit diagram of a switching device for a general-purpose electrical phase is shown according to another embodiment of the present invention. Detailed Implementation

[0042] Referring to the accompanying drawings, the present invention relates to a switchgear 500 suitable for installation in AC or DC low-voltage electrical systems.

[0043] For the purposes of this invention, the term "low voltage" generally refers to operating voltages of up to 2.0 kV AC and 2.5 kV DC.

[0044] According to the present invention, the switching device 500 includes a switching device 100, such as a circuit breaker, a disconnecting switch, a contactor, etc.

[0045] The switching device 100 includes one or more switching poles 1.

[0046] The number of switching poles in the switching device 100 can vary as needed. For example, the switching device 100 can be a three-phase type, and therefore includes three switching poles. However, in principle, the switching device can include different numbers of switching poles.

[0047] Each switch pole 1 of the switching device 100 includes a first terminal 7 and a second terminal 8 that can be connected to the corresponding conductor of an electric wire.

[0048] In operation, the terminals 7 and 8 (in a known manner) are electrically coupled to the corresponding conductors of the wire. These conductors are then electrically connected to a power source (e.g., a power transmission or generation system or part of a power grid) and an electrical load (e.g., a power system or equipment or part of a power grid).

[0049] For clarity, it should be noted that the terms “connection” and “disconnection” as used in this disclosure refer to the electrical and mechanical connection / disconnection of different components, unless otherwise stated or self-evident from the description or drawings.

[0050] Preferably, the switch electrode 1 includes an insulating housing 2, which defines an internal volume comprising a contact area 3 and an arc-extinguishing area 4. Figure 3 ).

[0051] Generally, the contact area 3 is part of the internal volume of the switching electrode, in which the contact assembly of the switching electrode is arranged and operates. On the other hand, the arc-extinguishing area 4 is part of the internal volume of the switching electrode, in which a suitable arc-extinguishing device is arranged, designed to extinguish any arc that may be generated between the electrical contacts of the switching electrode during disconnection operation.

[0052] The contact region 3 and the arc-extinguishing region 4 are preferably adjacent and hydrodynamically connected to each other. Preferably, the arc-extinguishing region 4 is located above the contact region 3, that is, at a proximal position relative to the top side of the contact region 3.

[0053] For clarity, it should be noted that the relative terms used in this disclosure, such as "front," "rear," "side," "upper," "lower," "top," and "bottom," are relative to the switch pole 1 in its normal mounting state, i.e., in a "vertical" mounting state. Figure 3 In terms of ).

[0054] The insulating housing 2 of the switch electrode is formed as a well-defined box with opposing first and second side walls, opposing top and bottom walls, and opposing front and rear walls 23, 24.

[0055] Preferably, the aforementioned extreme terminals 7 and 8 are positioned at the rear wall 24 of the insulating housing of the switching electrode.

[0056] The insulating shell 2 is preferably made of an electrically insulating material, such as a thermosetting or thermoplastic material.

[0057] According to the present invention, the switch electrode 1 includes a fixed contact assembly 5 and a movable contact assembly 6 arranged in the contact area 3 of the switch electrode. Figure 3 , Figures 9-14 ).

[0058] The fixed contact assembly 5 includes one or more fixed electrical contacts 51, 52, which are typically electrically connected to the first terminal 7.

[0059] More specifically, the fixed contact assembly 5 includes one or more first fixed contacts 51 and one or more second fixed contacts 52, the second fixed contacts 52 being spaced apart from and electrically insulated from the fixed contacts 51.

[0060] Therefore, the first and second fixed contacts 51 and 52 are electrically connected to the first terminal 7, but they are spaced apart from each other.

[0061] Preferably, the first and second fixed contacts 51 and 52 are positioned on the rear wall 24 of the insulating housing of the switch pole.

[0062] Preferably, the first and second fixed contacts 51 and 52 are respectively arranged at the far end and near end of the arc-extinguishing region 4 relative to the switching pole.

[0063] Preferably, the first fixed contact 51 is formed by a pair of conductive tips arranged on the first conductive base 51A, and the first conductive base 51A is directly connected to the first terminal 7. Figure 6-Figure 8 , Figures 11-19 ).

[0064] Similarly, the second fixed contact 52 is preferably formed by a pair of conductive tips arranged on a second conductive base 52A, which is electrically connected to the first terminal 7 via other conductive components of the switching electrode, as will become more apparent below.

[0065] Preferably, the first and second fixed contacts 51 and 52 protrude at different heights relative to the common reference plane defined by the respective conductive bases 51A and 52A. More specifically, the first fixed contact 51 protrudes at a greater height than the second fixed contact 52. Figures 9-14 ).

[0066] Preferably, the fixed contact assembly 5 includes a first spacer 53 of electrically insulating material, which is inserted between the first and second fixed contacts 51 and 52 to electrically insulate the first and second fixed contacts 51 and 52 from each other. Figure 3-Figure 5 , Figures 9-14 ).

[0067] Preferably, the fixed contact assembly 5 includes a second spacer 54 of electrically insulating material, which is inserted between the first terminal 7 and the second fixed contact 52 to prevent direct electrical coupling between these components (which are interconnected via other conductive parts of the switching pole, as will become clearer below).

[0068] Preferably, the fixed contact assembly 5 includes an elongated conductive plate 55 (e.g., formed of a metallic material) electrically connected to the second fixed contact 52. The conductive plate 55 extends from the second fixed contact 52 toward the arc-extinguishing region 4 and is disposed at the rear wall 24 of the insulating housing 2. Figure 3-Figure 5 ).

[0069] The movable contact assembly 6 includes one or more movable electrical contacts 61, 62, which are typically electrically connected to the second terminal 8. Figure 3 , Figures 9-14 ).

[0070] More specifically, the movable contact assembly 6 includes one or more first movable contacts 61 and one or more second movable contacts 62.

[0071] Preferably, the first and second movable electrical contacts 61 and 62 are electrically connected to each other and to the second terminal 8.

[0072] Preferably, the first and second movable electrical contacts 61 and 62 are respectively arranged at the far end and near end of the arc-extinguishing region 4 relative to the switching pole.

[0073] Preferably, the first and second movable contacts 61 and 62 are formed by the first and second pairs of conductive fingers, respectively, and protrude from the conductive head 65 which is electrically connected to the second terminal 8.

[0074] The movable contact assembly 6 can be reversibly moved about a rotation axis A1, which is preferably perpendicular to the sidewall of the insulating housing of the switch pole (such a rotation axis A1 is perpendicular to...). Figure 3 , Figures 9-14 (the plane).

[0075] Preferably, the movable contact assembly 6 includes a support structure 63 for the movable contacts 61, 62. This support structure can be easily rotated about the rotation axis A1 and includes a connecting element 64 that protrudes to the outside of the insulating housing of the switching pole (preferably from a suitable window in the front wall 23) for connection with a drive mechanism (not shown).

[0076] Preferably, the conductive head 65, on which movable contacts 61 and 62 are mounted, is hinged to the support structure 63. Therefore, the conductive head 65 rotates together with the support structure 63, and when the support structure 63 moves, the conductive head 65 can rotate slightly relative to the support structure about another axis of rotation A2.

[0077] In this way, when the support structure 63 rotates according to the rotation direction, the conductive head 65 can tilt slightly relative to the support structure 63 with relative rotational movement.

[0078] The movable contact assembly 6 can rotate around the axis A1 at the first position P1. Figure 9 and Figure 11 ) and second position P2 ( Figure 10 and Figure 14 Move between ).

[0079] In this way, the first movable contact 61 can be connected to or disconnected from the first fixed contact 51, while the second movable contact 62 can be connected to or disconnected from the second fixed contact 52.

[0080] The first position P1 of the movable contact assembly 6 corresponds to the closed state of the switch pole, in which current can flow between the terminals of the switch pole, while the second position P2 of the movable contact assembly 6 corresponds to the open state of the switch pole, in which the current flowing along the switch pole is interrupted.

[0081] Conveniently, the movable contact assembly 6 moves between a first position P1 and a second position P2 by rotating about the rotation axis A1 in opposite directions of rotation.

[0082] For each switch pole, the transition of the movable contact assembly 6 from the first position P1 to the second position P2 constitutes the disconnection operation of the switching device 100.

[0083] For each switch pole, the reverse transition of the movable contact assembly 6 from the second position P2 to the first position P1 constitutes the closing operation of the switching device 100.

[0084] Advantageously, the movable contact assembly 6 and the fixed contact assembly 5 are arranged such that during the disconnection operation of the switching poles ( Figures 11 to 14 The first and second movable contacts 61 and 62 are disconnected from the first and second fixed contacts 51 and 52 according to a specific disconnection sequence (described below).

[0085] When the movable contact assembly 6 is in the first position P1 (switch closed), the first movable contact 61 is connected to the first fixed contact 51, while the second movable contact 62 is disconnected from the second fixed contact 52. Figure 11 ).

[0086] During the opening operation of the switch pole, when the initial movement is made around the rotation axis A1 according to the rotation direction R ( Figures 11-12 The movable contact assembly 6 moves from the first position P1 to the first intermediate position P3. Figure 12 The first movable contact 61 is connected to the first fixed contact 51, and the second movable contact 62 is connected to the second fixed contact 52. When the movable contact assembly 6 moves from the first position P1 to the first intermediate position P3, the first movable contact 61 rotates about the rotation axis A2.

[0087] When moving further according to the rotation direction R ( Figures 12-13 The movable contact assembly 6 moves from the first intermediate position P3 to the second intermediate position P4. Figure 13 In this configuration, the first movable contact 61 is decoupled from the first fixed contact 51, while the second movable contact 62 is connected to the second fixed contact 52.

[0088] After moving further according to the rotation direction R ( Figures 13-14 The movable contact assembly 6 moves from the second intermediate position P4 to the second position P2. Figure 14 ).

[0089] When the movable contact assembly 6 is in the second position P2, the first movable contact 61 is decoupled from the first fixed contact 51, and the second movable contact 62 is decoupled from the second fixed contact 52. When the movable contact 6 moves from the second intermediate position P4 to the second position P2, the second movable contact 62 is decoupled from the second fixed contact 52.

[0090] from Figures 11 to 14 It is evident that the above-mentioned disconnection sequence of electrical contacts 51, 52, 61, and 62 can be achieved through the special arrangement of movable contacts 61 and 62 (mounted on tilting head 65) and fixed contacts 51 and 52 (protruding at different heights from corresponding conductive bases 51A and 52A).

[0091] Advantageously, the movable contact assembly 6 and the fixed contact assembly 5 are arranged such that the first and second movable contacts 61 and 62 are connected to the first and second fixed contacts 51 and 52 in a specific closing sequence during the closing operation of the switch pole. The closing sequence of the electrical contacts is substantially the reverse of the opening sequence described above. No electric arc is generated during the closing operation of the switch pole.

[0092] Preferably, the switch electrode 1 includes an arc-extinguishing chamber 40 positioned in the arc-extinguishing region 4, conveniently located above the contact region 3. Figure 3 , Figures 9-10 ).

[0093] The arc-extinguishing chamber 40 includes multiple arc-extinguishing elements 41, designed to extinguish any arc that may occur between the electrical contacts 51, 52, 61, and 62 when the electrical contacts 51, 52, 61, and 62 are separated during the disconnection operation of the switching poles. Figures 11-14 ).

[0094] The arc-breaking element 41 of the arc-extinguishing chamber 40 includes a series of parallel arc-breaking plates, preferably arranged along a reference plane that is parallel to the front wall 23 and rear wall 24 of the insulating housing 2 and perpendicular to the side walls 21 and 22. The arc-breaking plates 41 are preferably arranged at a subsequent position between the front wall 23 and the rear wall 24, with the distance from the fixed contact assembly 5 gradually increasing.

[0095] Preferably, the arc-extinguishing plate 41 is formed of a well-defined metal plate or ceramic plate, which may have different sizes and shapes as needed.

[0096] According to the present invention, for each switching pole of the switching device 100, the switching device 500 includes a current limiter 200.

[0097] During the disconnection operation of the switching device, the current flowing along the corresponding switching pole 1 of the switching device 100 is restricted or disconnected, especially when the first movable contact 61 of the switching pole is decoupled from the first fixed contact 51 and the current flowing along the switching pole passes entirely through the second movable contact 62 and the second fixed contact 52 of the switching pole, because these contacts are still connected or because an electric arc is generated between these contacts.

[0098] Each current limiter 200 effectively helps to extinguish any arcing that may occur between the movable contact assembly 6 and the fixed contact assembly 5, because the current limiter 200 intervenes during the most critical phase of disconnection operation when the movable contact assembly 6 is disengaging from the fixed contact assembly 5 and an arc may strike between the electrical contacts of the switching poles.

[0099] According to the present invention, each current limiter 200 is electrically connected in series with the second fixed contact 52 and the first terminal 7 of the corresponding switch pole 1.

[0100] Figure 6 A schematic circuit diagram of a switching device for a general-purpose electrical phase is shown.

[0101] For each electrical phase, the switching device 500 includes a switching pole 1 of the switching device 100 and a current limiter 200 that are electrically connected to each other.

[0102] The current limiter 200 includes a first terminal 201 and a second terminal 202. The first terminal 201 is connected to the second fixed contact 52 of the switch electrode 1 (conveniently connected to the conductive base 52A supporting the fixed contact), and the second terminal 202 is connected to the first terminal 7 of the switch electrode 1.

[0103] Therefore, the second fixed contact 52, the current limiter 200 and the first terminal 7 form a series circuit 210, along which current can flow during the disconnection operation of the switching device 100.

[0104] Each current limiter 200 may include multiple current limiting units (or even different types of current limiting units) electrically connected in series, parallel, or series-parallel configurations as needed.

[0105] The current limiter 200 is configured to limit or interrupt the current flowing along the series circuit 210 when the first movable electrical contact 61 of the switch pole 1 is disconnected from the corresponding first fixed electrical contact 51.

[0106] Now for reference Figures 9 to 18 The operation of the switching device 500 for general electrical phases is described in more detail.

[0107] Figure 11 The switching pole 1 of the switching device 100 is shown, wherein the movable contact assembly 6 is in the first position P1 (the closed state of the switching pole).

[0108] In this configuration, the first movable contact 61 is connected to the first fixed contact 51, and the second movable contact 62 is disconnected from the second fixed contact 52.

[0109] The electrode current I can flow along the switching electrode between terminals 7 and 8. The electrode current I passes entirely through the first movable contact 61 and the first fixed contact 51. Figure 15 Since the second movable contact 62 and the second fixed contact 52 are decoupled, no current flows along the current limiter 200.

[0110] Because the extreme terminals 7 and 8 are short-circuited, no electric arc will be generated between the movable contact assembly 6 and the fixed contact assembly 5.

[0111] In this situation, the current limiter 200 does not intervene.

[0112] Figure 12 The switch pole 1 with a movable contact assembly 6 is shown in the first intermediate position P3, when the movable contact assembly rotates around the rotation axis A1 according to the rotation direction R. Figures 11-12 It reached that position when it initially moved slightly.

[0113] In this configuration, the first movable contact 61 is connected to the first fixed contact 51, and the second movable contact 62 is connected to the second fixed contact 52.

[0114] Electrode current can still flow between terminals 7 and 8. However, this electrode current is shunt between the first current I1 passing through the first movable contact 61 and the first fixed contact 51 and the second current I2 passing through the second movable contact 62, the second fixed contact 52 and the current limiter 200. Figure 16 ).

[0115] The second current I2 is typically lower than the first current I1 because it circulates along a conductive path that typically has a higher equivalent resistance.

[0116] Since the extreme terminals 7 and 8 are still in a short-circuit state, no electric arc will be generated between the movable contact assembly 6 and the fixed contact assembly 5.

[0117] In this situation, the current limiter 200 does not intervene.

[0118] Figure 13 The switch pole 1 with movable contact assembly 6 is shown at the second intermediate position P4, when the movable contact assembly 6 rotates according to the rotation direction R ( Figure 12-14 It will reach this position when it moves further.

[0119] In this case, the first movable contact 61 is decoupled from the first fixed contact 51, and the second movable contact 62 is connected to the second fixed contact 52.

[0120] Since terminals 7 and 8 are still in a short-circuit state, the electrode current I can still flow between terminals 7 and 8 along the switch electrode. The electrode current I passes completely through the second movable contact 62, the second fixed contact 52, and the current limiter 200. Figure 17 ).

[0121] No current flows along the first movable contact 61 and the first fixed contact 51 because the latter has been disconnected.

[0122] Since the extreme terminals 7 and 8 are still in a short-circuit state, no electric arc will be generated between the movable contact assembly 6 and the fixed contact assembly 5.

[0123] In this situation, as soon as the movable contact assembly 6 reaches the second intermediate position P4, the current limiter 200 will intervene to limit or interrupt the current flowing along the switch pole.

[0124] If it is configured to limit the current flowing through the switch pole, the current limiter 200 will continue to operate when the movable contact assembly 6 moves from the second intermediate position P4 to the second position P2 until the current flowing along the switch pole is finally interrupted due to the separation of the movable contact assembly 6 from the fixed contact assembly 5.

[0125] If configured to interrupt the current through the switch pole, the current limiter 200 will begin to cut off the current during the disconnection operation of the switching device 100.

[0126] If the intervention speed is particularly fast (e.g., because it includes a solid-state switching circuit), the current limiter 200 can complete its current-breaking operation while the second movable contact 62 is still connected to the second fixed contact 52. In this case, the subsequent separation of the second movable contact 62 from the second fixed contact 52 will occur substantially in the absence of an electric arc.

[0127] However, when the second movable contact 62 is still connected to the second fixed contact 52, the current limiter 200 may fail to complete the current interruption operation. In this case, the current limiter 200 will intervene after the second movable contact 62 is disconnected from the second fixed contact 52, until the current flowing along the switch pole 1 is finally interrupted. In this case, an electric arc may occur between the movable contact assembly 6 and the fixed contact assembly 5.

[0128] When according to the rotation direction R ( Figure 12-14 When the movement is further, the second movable contact 62 is also decoupled from the second fixed contact 52, and the movable contact assembly 6 moves to the second position P2 (the open state of the switch pole).

[0129] When the movable electrical contacts 61 and 62 are disconnected from their corresponding fixed electrical contacts 51 and 52 during the disconnection operation phase, the voltage potential difference between the first and second terminals 7 and 8 increases. At any given time, the second terminal (and the movable contacts 61 and 62) may have a positive voltage polarity, while the first terminal 7 (and the fixed contacts 51 and 52) may have a negative voltage polarity, and vice versa. Because the dielectric distance between the movable contacts 61 and 62 and the fixed contacts 51 and 52 is very short, an electric arc may occur between the separated movable contact assembly 6 and the fixed contact assembly 5. In this case, the arc-extinguishing element 41 facilitates the extinguishing process of the arc.

[0130] The possible occurrence of these arcs will allow arc current I arc The circuit passes through the second movable contact 62, the second fixed contact 52, and the current limiter 200. Figure 18 ).

[0131] However, during the disconnection phase, the current limiter 200 has intervened to limit or interrupt the current flowing along the switch poles.

[0132] If configured to limit the current flowing through the switching poles, the current limiting device 200 can effectively help extinguish any arcs that may occur between the separated movable contact assembly 6 and the fixed contact assembly 5, because these arcs occur at a low energy level and are therefore easier to extinguish.

[0133] If the current limiter 200 is configured to disconnect the current flowing through the switch poles, it can complete its current disconnection action during this phase of the disconnection operation of the switching device 100. In this case, the intervention of the current limiter 200 causes any arc that may occur between the disengaged movable contact assembly 6 and the fixed contact assembly 5 to be forcibly extinguished because the arc current I... arc It cannot be recycled through the switch poles.

[0134] If the current limiter 200 has completed its current-breaking action before the second movable contact 62 is disconnected from the corresponding second fixed contact 52 (because the current limiter intervenes very quickly), no arc will be generated because the arc current cannot circulate through the switching poles. Therefore, the final stage of the disconnection operation can occur without any arcing phenomenon.

[0135] Finally, when the movable contact assembly 6 reaches the second position P2 (the open state of the switch pole), the disconnection operation is completed. In this case, any ongoing potential arcing will continue its extinguishing process with the help of the arc-extinguishing element 41 and the current limiter 200.

[0136] According to some embodiments of the present invention, the current limiter 200 includes an electromechanical auxiliary switching device, such as a circuit breaker. Figure 1 and Figure 7 In this case, each current limiter 200 includes at least a switching pole 200 of an auxiliary switching device. The ratings of the switching poles 1 of the auxiliary switching device can be much lower than the normal operating values ​​in the switching device because they operate during the disconnection operation of the switching device 100.

[0137] The electromechanical switching device 200 can be of the automatic type, used to perform disconnection operations. In this case, the transition from the closed state to the open state (disconnection operation) occurs by utilizing the electrodynamic force generated by the circulation of current along the switching poles. Therefore, the disconnection operation of this type of switching device occurs in a very short time (rapid switching) without receiving input control signals or external power supply (uncontrolled disconnection operation).

[0138] As an alternative, the electromechanical switching device 200 can also be fully controllable. In this case, any transition from a closed state to an open state (disconnection operation) or from an open state to a closed state (closed operation) occurs in response to receiving an appropriate input control signal, which causes activation of a drive mechanism that moves a movable contact or triggers movement of the movable contact of each switching pole.

[0139] Generally, the electromechanical switching device 200 can be implemented according to known types of solutions. Therefore, for the sake of brevity, the following description will only refer to aspects of interest to the present invention.

[0140] According to other embodiments of the invention, the current limiter 200 includes at least a solid-state switching circuit for each switching pole of the switching device 100. Figure 1 and Figure 6 ).

[0141] Each switching circuit 200 includes one or more switching components based on semiconductor materials. Typically, the semiconductor switching components can be of conventional types, such as, for example, power MOSFETs, JFETs, insulated gate bipolar transistors (“IGBTs”), gate turn-off thyristors (GTOs), integrated gate commutated thyristors (“IGCTs”), etc.

[0142] In response to receiving an appropriate input control signal, each solid-state switch 200 can reversibly switch between a conduction current on state and a blocking current off state.

[0143] When the solid-state switch circuit 200 switches from the ON state to the OFF state, the solid-state switch circuit 200 is turned off; when the solid-state switch circuit 200 switches from the OFF state to the ON state, the solid-state switch circuit 200 is turned on.

[0144] The transition from the ON to the OFF state in the solid-state switching circuit 200 is typically very rapid. Therefore, each solid-state switching circuit 200 can interrupt the current flowing along the corresponding switching electrode 1 of the switching device 100 before the second movable contact 62 is decoupled from the corresponding second fixed contact 52. In this case, the disconnection operation of the switching device 100 will occur without arcing.

[0145] Generally, the solid-state switching circuit 200 can be implemented according to known types of solutions. Therefore, for the sake of brevity, it will be described below only with reference to aspects of interest to the present invention.

[0146] According to other embodiments of the invention, the current limiter 200 includes at least a fuse circuit 200 for each switching pole of the switching device 100. Figure 1 and Figure 6 ).

[0147] Each fuse circuit 200 can be conveniently configured to operate when a specific energy (I) of the flowing current is present. 2 The current flowing through the fuse is interrupted when a certain threshold is exceeded. In practice, each fuse circuit 200 can be configured to intervene only if a high-energy arc may occur during the disconnection operation of the switching device 100. Obviously, the fuse circuit 200 should be replaced after intervention.

[0148] Generally, the fuse circuit 200 can be implemented using known types of solutions. Therefore, for the sake of brevity, it will be described below only with reference to aspects of interest to the present invention.

[0149] According to other embodiments of the invention, the current limiter 200 includes at least a resistive circuit (e.g., a rheostat circuit) or a resonant circuit 200 (e.g., an RLC circuit of different configurations) for each switching pole of the switching device 100. Figure 1 and Figure 6 ).

[0150] Each resistor circuit or resonator 200 can be conveniently configured to increase the total impedance of the conductive path of the current through the corresponding switching electrode of the switching device 100 during the disconnection operation of the switching device 100. In this way, a lower energy arc may occur during the disconnection operation of the switching device 100, and the arc that may occur between the electrical contacts of the switching electrode of the switching device 100 can be extinguished more easily.

[0151] Generally, the resistor or resonant circuit 200 can be implemented according to known types of solutions. Therefore, for the sake of brevity, they will be described below only with reference to the aspects of interest of the present invention.

[0152] According to another embodiment of the invention, the current limiter 200 includes an electromechanical auxiliary switching device 200 (e.g., a circuit breaker) for each switching pole 1 of the switching device 100. Figure 2 and Figure 8 ).

[0153] In principle, each switching device 200 may have a single switching pole, which is connected in series with the second electrical contact 52 and the first terminal 7 of the corresponding switching pole of the switching device 100 (the other switching poles of the switching device 200 may remain floating).

[0154] Preferably, each auxiliary switching device 200 has multiple switching poles, which are connected in series with the second electrical contact 52 and the first terminal 7 of the corresponding switching pole of the switching device 100.

[0155] This solution is highly advantageous because it allows for an increase in the operating voltage of the switching device 500. In fact, each current limiter 200 can withstand a higher voltage potential difference during the disconnection operation of the switching device 100, especially when the second movable contact 62 of each switching pole is disengaged from the corresponding second fixed contact 52 (the transition between the operating positions P4 and P2 of the movable contact assembly 6).

[0156] Generally, the electromechanical switching device 200 can be implemented according to known types of solutions. Therefore, for the sake of brevity, it will be described below only with reference to the aspects of interest of the present invention.

[0157] According to other embodiments, the current limiter 200 includes a hybrid switching circuit comprising a combination of at least an electromechanical switching device and at least a semiconductor-based solid-state switching device. This hybrid switching circuit is electrically connected to the corresponding switching electrode of the switching device.

[0158] According to some embodiments of the present invention ( Figure 19 The switching device 100 includes a magnetic field generating device for each switching pole 1, which is configured to generate a magnetic field during the disconnection operation of the switching device.

[0159] Each magnetic field generating device includes a first coil conductor 11 and a second coil conductor 12 wound around a winding axis parallel to the rotation axis A1 of the movable contact assembly 6.

[0160] The first and second coil conductors 11 and 12 are conveniently arranged according to the Helmholtz coil configuration. Therefore, they are spaced apart from each other along their winding axis and connected in series, such that the same current flows along them in the same direction.

[0161] Preferably, the first and second coil conductors 11 and 12 are arranged on opposite sidewalls of the insulating shell of the switch electrode, outside the internal volume of the switch electrode.

[0162] The first and second coil conductors 11 and 12 are connected in series with the second fixed contact 52 of the switch pole 1, the first terminal 7 of the switch pole 1, and the corresponding limiter 200.

[0163] Figure 19 A schematic circuit diagram of a switching device for a general-purpose electrical phase according to an embodiment of the present invention is shown.

[0164] For each electrical phase, the switching device 500 includes a switching pole 1 of the switching device 100 and a current limiter 200 that are electrically connected to each other.

[0165] The switch pole 1 includes a magnetic field generating device, which includes first and second coil conductors 11 and 12.

[0166] The first and second coil conductors 11 and 12 respectively have first and second coil terminals 13 and 14, and third and fourth coil terminals 15 and 16.

[0167] The first coil terminal 13 of the first coil conductor 11 is electrically connected to the second fixed contact 52 of the switch pole 1, the second coil terminal 14 of the first coil conductor 11 is electrically connected to the third coil terminal 15 of the second coil conductor 12, and the fourth coil terminal 16 of the second coil conductor 12 is electrically connected to the first terminal 7.

[0168] The first coil terminal 13 of the first coil conductor 11 is electrically connected to the second terminal 202 of the current limiter 200, while the second coil terminal 14 of the first coil conductor 11 is electrically connected to the first terminal 201 of the current limiter 200.

[0169] Clearly, the second fixed contact 52, the first coil conductor 11, the current limiter 200, the second coil conductor 12, and the first terminal 7 form a series circuit 210, along which current can flow during the disconnection operation of the switching device 100.

[0170] During the disconnection operation of the switching device, a magnetic field is generated by the magnetic field generating device when current flows through the second movable contact 62 of the movable contact assembly 6 and the second fixed contact 52 of the fixed contact assembly 5 (and thus along the aforementioned series circuit 210).

[0171] According to the general electrical phase operation of the above-described switching device, when the movable contact assembly 6 of the corresponding switch pole of the switching device 100 moves from the first intermediate position P3 to the second intermediate position P4, and possibly when the movable contact assembly 6 moves from the second intermediate position P4 to the second position P2 (if an electric arc occurs between the electrical contacts of the switch pole), the current flows along the coil conductors 11 and 12.

[0172] When current flows along coil conductors 11 and 12, a magnetic field is generated. In the case of separation (when the second movable contact 62 is disconnected from the second fixed contact 52), the arc that may be generated between the fixed contact assembly 5 and the movable contact assembly 6 is affected by the magnetic force (Lorentz force) pointing towards the arc-extinguishing region 4 of the switching pole. This magnetic force causes the arc to move towards the arc-extinguishing region 4.

[0173] In fact, in the separated state, any arcs that may be generated between the fixed contact assembly 5 and the movable contact assembly 6 are "blown" towards the arc-extinguishing region 4 by the generated magnetic field. They can therefore be evenly distributed among the arc-breaking elements 41 in the arc-extinguishing chamber 40, thus effectively extinguishing the arcs.

[0174] The magnetic field generated by the magnetic field generating device allows the arc to be more effectively confined within the arc extinguishing region 4, thereby reducing the possibility of other conductive parts toward the switching electrode being struck again.

[0175] Even in the presence of a magnetic field generating device, the current limiter 200 electrically connected to the switch electrode behaves as described above.

[0176] Therefore, when the first movable electrical contact 61 of the switch pole 1 is decoupled from the corresponding first fixed electrical contact 51, more specifically, when the movable contact assembly reaches the second intermediate position P4 and moves from the second intermediate position P4 to the second position P2, the current limiter 200 will limit or interrupt the current flowing along the series circuit including the second fixed contact 52, the first coil conductor 11, the current limiter 200, the second coil conductor 12 and the first terminal 7.

[0177] Generally, the aforementioned magnetic field generating devices can be implemented using known types of solutions. Therefore, for the sake of brevity, they will be described below with reference only to aspects of interest to this invention.

[0178] The switching device according to the present invention exhibits relevant advantages.

[0179] The current limiter 200, which is associated with the switching pole operating ground of the switching device 100, provides or significantly facilitates the effective extinguishing process of an electric arc that may occur between the disconnected electrical contacts during the disconnection operation of the switching device.

[0180] The internal components of the arc-extinguishing chamber 40 and, more generally, the switching poles of the switching device 100 are subjected to lower mechanical and thermal stresses, thus extending their service life.

[0181] Additionally, the current limiting or breaking action of the current limiter 200 allows for a reduction in the likelihood of arcing to other conductive parts of the switching poles of the switching device 100 during the disconnection operation of the switching device 100.

[0182] The switching device of the present invention has a relatively simple and compact structure, is relatively easy to manufacture at the industrial level, and has a competitive cost compared with currently available solutions on the market.

Claims

1. A switching device (500) comprising a switching apparatus (100) having one or more switching poles (1), wherein the switching poles of the switching apparatus include: The first terminal (7) and the second terminal (8) can be connected to the corresponding conductor of the wire; The fixed contact assembly (5) includes a plurality of fixed electrical contacts (51, 52) electrically connected to the first terminal (7), the fixed electrical contacts including one or more first fixed contacts (51) and one or more second fixed contacts (52) electrically insulated from the first fixed contacts; A movable contact assembly (6) includes a plurality of movable electrical contacts (61, 62) electrically connected to the second terminal (8), the movable electrical contacts including one or more first movable contacts (61) and one or more second movable contacts (62), the movable contact assembly being reversibly movable about a rotation axis (A1) such that when the movable contact assembly (6) moves about the rotation axis, the first movable contact (61) can be engaged or disengaged from the first fixed contact (51), and the second movable contact (62) can be engaged or disengaged from the second fixed contact (52); The characteristic feature is that, for each switch pole (1) of the switching device, the switching device (500) includes: a current limiter (200) electrically connected in series with the second fixed contact (52) and the first terminal (7) of the switch pole. The current limiter (200) is configured to limit or interrupt the flow of current (I2, I3) along the series circuit (210) comprising at least the second fixed contact (52), the current limiter (200), and the first terminal (7) during the disconnection operation of the switching device, when the first movable electrical contact (61) is decoupled from the first fixed contact (51). arc ).

2. The switching device according to claim 1, characterized in that, The movable contact assembly (6) of the switch electrode (1) is reversibly movable between a first position (P1) and a second position (P2) about the rotation axis (A1), the first position corresponding to the closed state of the switch electrode and the second position corresponding to the open state of the switch electrode. When the movable contact assembly (6) is in the first position (P1): The first movable contact (61) is connected to the first fixed contact (51); The second movable contact (62) is decoupled from the second fixed contact (52); When the movable contact assembly (6) is in the second position (P2): The first movable contact (61) is decoupled from the first fixed contact (51); The second movable contact (62) is decoupled from the second fixed contact (52).

3. The switching device according to claim 2, characterized in that, During the disconnection operation of the switching device (100), the movable contact assembly (6) moves from the first position (P1) to a first intermediate position (P3), in which: The first movable contact (61) is connected to the first fixed contact (51); The second movable contact (62) is connected to the second fixed contact (52).

4. The switching device according to claim 3, characterized in that, During the disconnection operation of the switching device (100), the movable contact assembly (6) then moves from the first intermediate position (P3) to the second intermediate position (P4), in which: The first movable contact (61) is decoupled from the first fixed contact (51); The second movable contact (62) is connected to the second fixed contact (52).

5. The switching device according to claim 4, characterized in that, During the disconnection operation of the switching device (100), the movable contact assembly (6) subsequently moves from the second intermediate position (P4) to the second position (P2). The current limiter (200) electrically connected to the switch pole (1) is configured to limit or break the current (I) flowing through the series circuit comprising at least the second fixed contact (52), the current limiter (200), and the first terminal (7) when the movable contact assembly (6) reaches the second intermediate position (P4) and moves from the second intermediate position (P4) to the second position (P2). arc ).

6. The switching device according to any one of the preceding claims, characterized in that, The switching device includes an electromechanical auxiliary switching device electrically connected to the switching pole (1) of the switching device (100), and the current limiter (200) includes at least the switching pole of the auxiliary switching device.

7. The switching device according to any one of the preceding claims, characterized in that, The current limiter (200) includes at least the electromechanical auxiliary switching device electrically connected to the corresponding switching pole (1) of the switching device (100).

8. The switching device according to claim 7, characterized in that, The auxiliary switching device (200) has multiple switching poles connected in series.

9. The switching device according to any one of the preceding claims, characterized in that, The current limiter (200) includes at least a solid-state switching circuit electrically connected to the corresponding switching pole (1) of the switching device (100).

10. The switching device according to any one of the preceding claims, characterized in that, The current limiter (200) includes a fuse circuit electrically connected to the corresponding switch pole (1) of the switching device (100).

11. The switching device according to any one of the preceding claims, characterized in that, The current limiter (200) includes a resistor circuit electrically connected to the corresponding switch pole (1) of the switching device (100).

12. The switching device according to any one of the preceding claims, characterized in that, The current limiter (200) includes a resonant circuit electrically connected to the corresponding switch pole (1) of the switching device (100).

13. The switching device according to any one of the preceding claims, characterized in that, The current limiter (200) includes a hybrid switching circuit electrically connected to a corresponding switch pole (1) of the switching device (100), wherein the hybrid switching circuit includes at least the electromechanical switching device and at least the solid-state switching circuit.

14. The switching device according to any one of the preceding claims, characterized in that, For each switching pole (1) of the switching device (100), the switching device includes a magnetic field generating device, which includes a first coil conductor (11) and a second coil conductor (12) wound around a winding axis parallel to the rotation axis (A1) of the movable contact assembly (6). The first coil conductor (11) and the second coil conductor (12) are spaced apart from each other along the winding axis and are connected in series with the second fixed contact (52), the current limiter (200), and the first terminal (7). The current limiter (200) is configured to, during the disconnection operation of the switching device, limit or interrupt the flow of current (I2, I3) along a series circuit (210) comprising at least the second fixed contact (52), the first coil conductor (11), the current limiter (200), the second coil conductor (12), and the first terminal (7) when the first movable electrical contact (61) is disengaged from the first fixed contact (51). arc ).

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