Detachable hybrid switch device

Abstract

The present application relates to a draw-out type hybrid switch device. A switch device for a distribution network, comprising: a draw-out first switch unit having one or more first electrodes; a draw-out second switch unit having one or more second electrodes and electrically connected in series with the first switch unit; wherein the second switch unit includes an emergency control arrangement that can be activated by a user to cause the second switch unit to perform an opening operation.

Description

Technical Field

[0001] The present invention relates to a switching device for a distribution network, such as a circuit breaker or other devices of a similar type. Background Art

[0002] As is well known, low-voltage switching devices are used in circuits or power grids to allow the correct operation of specific circuits or parts of the power grid. For example, these devices can be used to ensure the nominal current required for various utilities, enable the correct insertion and disconnection of electrical loads, and protect (especially circuit breakers) the power grid and installed electrical loads from fault events such as overloads and short circuits.

[0003] Most traditional switching devices include an electromechanical switching unit having one or more electrodes, each electromechanical switching unit including a pair of electrical contacts adapted to couple or decouple to allow or interrupt the line current along the electrodes.

[0004] Although they have proven to be very robust and reliable, switching devices of the electromechanical type show a relatively long interruption time in DC applications, mainly at relatively high voltages (between DC 1 - 1.5 kV). Therefore, the arc that usually strikes between the electrical contacts during separation will last for a relatively long time. This causes a serious wear phenomenon of the electrical contacts and thus leads to a significant reduction in working reliability and electrical durability.

[0005] To overcome these technical problems, they have designed a switching device including a switching unit (also referred to as "SSCB" - solid-state circuit breaker), for each electrode, the switching unit having one or more solid-state switches, that is, semiconductor-based transistors or thyristors, which are adapted to operate in a conducting state or a blocking state to allow or interrupt the current flow.

[0006] The main advantage of SSCB is that, due to the situation of performing the disconnection operation without forming an arc, they have potentially unlimited electrical tolerance. Additionally, compared with the interruption time of electromechanical switching devices, their interruption time is significantly shorter.

[0007] An important disadvantage of SSCB is that they generally cannot provide electrical insulation between the line conductors to which they are connected. In fact, when a voltage is applied to the power terminals of the solid-state switch (for example, the collector and emitter terminals of an IGBT), even when the switch is in the blocking state, leakage current usually circulates.

[0008] Recently, a switching device including an SSCB switching unit and an electromechanical switching unit connected in series has been developed.

[0009] These switching devices (generally referred to as "hybrid switching devices") allow taking advantage of all the benefits of the SSCB in terms of reliability and reduced interruption time, and at the same time, they allow obtaining galvanic insulation between the line conductors connected thereto.

[0010] As is known, many hybrid switching devices are of the "draw-out" type. In this case, both the SSCB and the electromechanical switching unit are movable relative to the fixed part of the switching device. In particular, each switching unit is mounted on a carriage in such a way as to be reversibly movable between an inserted position and a withdrawn position relative to the fixed part of the switching device.

[0011] In terms of operating efficiency and safety, the draw-out type of hybrid switching device has further advantages. In fact, it is possible to place both of the above-mentioned switching units in the withdrawn position so as to easily perform on-site tests or maintenance interventions with the switching units completely disconnected from the line conductors.

[0012] However, there are still some aspects of these switching devices that need to be improved, especially with reference to their operation in emergency situations, and more particularly in the case where, for any reason (such as the fact that the switching device is unable to receive an external auxiliary power supply), it is not possible to perform the opening manoeuvre of the electromechanical switching unit.

[0013] As can be easily understood, even when the SSCB switching unit is in the off state, such an event results in the inability to provide electrical insulation between the line conductors electrically connected to the switching device.

[0014] Since leakage current still flows along the electrodes of the switching device, this situation can be very dangerous for the personnel operating on-site, especially if an attempt is made to perform the withdrawal manoeuvre of the switching unit (e.g., the SSCB switching unit). Summary of the Invention

[0015] The main object of the present invention is to provide a draw-out type of hybrid switching device that makes it possible to overcome or mitigate the technical problems of the prior art level mentioned above.

[0016] Within this object, it is an object of the present invention to provide a switching device that ensures a high level of safety even when it has to operate in an emergency situation.

[0017] Another object of the present invention is to provide a switching device that can be easily controlled during operation without the need to arrange complex and expensive control resources.

[0018] Another object of the present invention is to provide a switching device that is relatively easy and inexpensive to manufacture at an industrial level.

[0019] According to the present invention, this object and these purposes, as well as other purposes that will become apparent from the following description and the accompanying drawings, are achieved by a switching device according to claim 1 and the related dependent claims listed below.

[0020] The switching device according to the present invention comprises:

[0021] - one or more first line terminals and second line terminals, which are respectively capable of being electrically connected to corresponding first line conductors and second line conductors of an electrical line;

[0022] - a first switching unit having one or more first electrodes. Each first electrode includes a first pole contact, a second pole contact capable of being electrically connected to the corresponding first line terminal, and one or more solid-state switches electrically connected to the first pole contact and the second pole contact and adapted to operate in a conducting state or a blocking state to allow or interrupt the flow of current. The first switching unit is capable of reversibly switching between a closed condition in which the solid-state switches are in the conducting state and an open condition in which the solid-state switches are in the blocking state. The first switching unit is reversibly movable between an inserted condition in which the first pole contact is coupled to the first line terminal and a withdrawn condition in which the first pole contact is decoupled from the first line terminal;

[0023] - a second switching unit having one or more second electrodes. Each second electrode includes a third pole contact capable of being electrically connected to the corresponding second pole contact of the first switching unit, a fourth pole contact capable of being electrically connected to the corresponding second line terminal, and an electrical contact electrically connected to the third and fourth pole contacts and adapted to operate in a coupled state or a decoupled state to allow or interrupt the flow of current. The second switching unit is capable of reversibly switching between a closed condition in which the electrical contact is in the coupled state and an open condition in which the electrical contact is in the decoupled state. The second switching unit is capable of reversibly moving between an inserted condition in which the fourth pole contact is coupled to the second line terminal and a withdrawn condition in which the fourth pole contact is decoupled from the second line terminal.

[0024] - a controller, adapted to control the operation of the switching device.

[0025] In the switching device according to the present invention, the second switching unit includes an emergency control arrangement that can be activated by a user to switch the second switching unit from the closed state to the open state.

[0026] The emergency control arrangement includes an emergency command button that can be operated by the user. The emergency command button is accessible to the user after removing one or more structural parts of the second switching unit.

[0027] Preferably, the second switch unit includes a first protection panel covering the emergency command button. After removing the first protection panel from the second switch unit, the user can access the emergency command button.

[0028] Preferably, the second switch unit includes a second protection panel covering the first protection panel. After removing the first protection panel and the second protection panel from the second switch unit, the user can access the emergency command button.

[0029] Preferably, each second electrode of the second switch unit includes at least a fixed electrical contact and a movable electrical contact. The second switch unit includes an actuating mechanism adapted to reversibly move one or more movable contacts of the second switch unit between a position coupled to the corresponding fixed contacts of the second switch unit and a position decoupled from the fixed contacts.

[0030] When the second switch unit is in the closed condition, the emergency control arrangement is adapted to trip the actuating mechanism to move the movable contact after being activated by the user. The actuating mechanism is adapted to move the movable contact from the coupled position with the fixed contact to the decoupled position from the fixed contact in response to the tripping of the emergency control arrangement, so that the second switch unit switches from the closed condition to the open condition.

[0031] Preferably, the emergency control arrangement includes a tripping element operatively coupled to the emergency command button. When the emergency command button is operated by the user to the activation position, the tripping element is adapted to trip the actuating mechanism.

[0032] Preferably, the emergency control arrangement includes a signal component adapted to provide a light signal to the user indicating the operating condition of the second switch unit.

[0033] Preferably, the emergency control arrangement includes a sensing component adapted to provide an alarm signal to the controller indicating the removal condition of the first protection panel.

[0034] Preferably, the controller is configured to: when the first switch unit is in the closed condition, in response to receiving the alarm signal, command the first switch unit to switch from the closed condition to the open condition.

[0035] Preferably, the controller is configured to: when the first switch unit is in the open condition, in response to receiving the alarm signal, prevent the first switch unit from switching to the closed condition.

[0036] According to one aspect of the present invention, the controller is configured to control the first switch unit and the second switch unit such that the first switch unit and the second switch unit operate combinatorially according to the following operation configurations:

[0037] - A first operation configuration corresponding to a closed state of the switching device, wherein both the first switch unit and the second switch unit are in a closed condition; or

[0038] - A second operation configuration corresponding to a standby state of the switching device, wherein the first switch unit is in an open condition and the second switch unit is in a closed condition; or

[0039] - A third operation configuration corresponding to an open state of the switching device, wherein both the first switch unit and the second switch unit are in an open condition.

[0040] According to one aspect of the present invention, the controller includes an interface portion that includes one or more input ports adapted to receive an input command indicating a desired operating state of the switching device.

[0041] Preferably, according to the present invention, the switching device includes a human-machine interface that communicates with the interface portion. The human-machine interface is adapted to provide the input command when interacting with a user.

[0042] Preferably, the interface portion is capable of receiving the input command from a remotely computerized device (9).

[0043] According to one aspect of the present invention, the controller is included in the first switch unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Other features and advantages of the present invention will become more apparent from the description of the preferred but non-exclusive embodiments illustrated in the drawings by way of example only and not by way of limitation, in which:

[0045] Figure 1 A switching device according to the present invention is schematically illustrated;

[0046] Figure 2 An electromechanical switch unit of a switching device according to the present invention is schematically illustrated.

[0047] Figures 3 - 4 5A, 5B, 5C schematically illustrate the operation of a switching device according to the present invention. DETAILED DESCRIPTION

[0048] Referring to the drawings mentioned above, the present invention relates to a switching device 100 for a distribution network, such as a circuit breaker, a disconnector, a contactor, etc.

[0049] The switching device 100 is particularly suitable for installation in a low-voltage electrical network or system. However, it can also be successfully used in a medium-voltage electrical network or system.

[0050] For the purposes of the present invention, the term "low voltage" (LV) relates to operating voltages below 1 kV AC and 1.5 kV DC, while the term "medium voltage" (MV) relates to higher operating voltages up to several tens of kV, for example up to 72 kV AC and 100 kV DC.

[0051] Generally speaking, the switching device 100 is intended to be electrically connected to an electrical line 50. Typically, the electrical line 50 includes one or more first line conductors 51 that can be electrically connected to an equivalent power source (e.g., a part of a power feed or generation system or electrical network), and one or more second line conductors 52 that can be connected to an equivalent electrical load (e.g., a part of an electrical system or device or electrical network).

[0052] In the embodiment shown in the figures, the electrical line 50 is of the three-phase type. However, in principle, it can include a different number of electrical phases.

[0053] The switching device 100 includes one or more first line terminals 91 and second line terminals 92, which are intended to be electrically connected to the corresponding first line conductor 51 and second line conductor 52 of the electrical line 50, respectively.

[0054] Conveniently, the first and second line terminals 91, 92 are accommodated in a fixed part of the switching device (not shown), which is conveniently defined by a support frame of the switching device (not shown).

[0055] The switching device 100 includes a first switching unit 1 of the SSCB type and a second switching unit 2 of the electromechanical type, which are electrically connected in series between the above-mentioned line terminals 91 and line terminal 92 during operation.

[0056] The first switching unit 1 includes one or more first electrodes 1A.

[0057] The number of electrodes of the first switching unit can vary as required. In the embodiment shown in the cited figures, the first switching unit is of the three-phase type and includes three electrodes. However, according to other embodiments of the present invention (not shown), the first switching unit can include a different number of electrodes.

[0058] Each electrode 1A is intended to be electrically connected to the corresponding first line conductor 51 of the electrical line 50 and is electrically connected to the corresponding electrode of the second switching unit 2.

[0059] Each electrode 1A includes a first pole contact 11 intended to be electrically connected to a corresponding first line terminal 91 of the switching device and a second pole contact 12 intended to be electrically connected to a corresponding pole contact 23 of the second switching unit 2.

[0060] Each electrode 1A includes one or more solid-state switches 10 adapted to operate in an on-state or an off-state to allow or interrupt the flow of current.

[0061] The solid-state switch (“SSCB”) 10 may include, for example, a MOSFET, an insulated-gate bipolar transistor (“IGBT”), a gate turn-off thyristor (GTO), an integrated gate-commutated thyristor (“IGCT”), etc.

[0062] The solid-state switches 10 of each electrode 1A are electrically connected, for example, in series configuration or in other more complex circuit configurations of known type, between the pole contacts 11 and 12.

[0063] In operation, the first switching unit 1 can be reversibly switched between a closed condition ON in which the solid-state switches 10 of the electrode 1A are in the on-state and an open condition OFF in which the solid-state switches 10 of the electrode 1A are in the off-state.

[0064] When the first switching unit 1 is in the closed condition ON, the line current is allowed to flow along the electrode 1A. Conversely, when the switching unit 1 is in the open condition OFF, the line current cannot flow along the electrode 1A. However, possible leakage currents can still circulate, which generally affect the solid-state switches in the off-state.

[0065] The transition from the closed condition ON to the open condition OFF forms an opening operation of the first switching unit, while the transition from the open condition OFF to the closed condition ON forms a closing operation of the first switching unit.

[0066] The first switching unit 1 can perform an opening operation or a closing operation when receiving a first trip signal T1 from the controller 3.

[0067] Preferably, the first switching unit 1 includes one or more first drive circuits (not shown) adapted to receive the first trip signal T1 and drive the control terminals (e.g., gate terminal or base terminal) of the solid-state switches 10 according to the trip signal T1.

[0068] The second switching unit 2 includes one or more second electrodes 2A.

[0069] Also in this case, the number of electrodes 2A of the switching unit 2 can vary as needed. Generally, the number of electrodes 2A corresponds to the number of electrodes 1A of the first switching unit 1.

[0070] Each electrode 2A is electrically connected in series with a corresponding electrode 1A of the first switching unit 1 and is intended to be electrically connected to a corresponding second line conductor 52 of the electrical line 50.

[0071] Accordingly, each electrode 2A includes a third pole contact 23 intended to be electrically connected to a corresponding second pole contact 12 of the first switching unit 1 and a fourth pole contact 24 intended to be electrically connected to the second line terminal 92 of the switching device.

[0072] Each second electrode 2A includes an electrical contact 20 which can be operated in a coupled state or a decoupled state to allow or interrupt the flow of current. Conveniently, the electrical contact 20 of each electrode 2A includes a fixed electrical contact and a movable electrical contact (not shown). Each movable contact can be actuated to couple with or decouple from the fixed contact.

[0073] In operation, the second switching unit 2 is capable of reversibly switching between a closed condition ON in which the electrical contact 20 of the electrode 2A is in the coupled state and an open condition OFF in which the electrical contact 20 of the electrode 2A is in the decoupled state.

[0074] When the second switching unit 2 is in the closed condition ON, the line current is allowed to flow along the electrode 2A. Conversely, when the second switching unit 2 is in the open condition OFF, the line current cannot flow along the electrode 2A.

[0075] The transition from the closed condition ON to the open condition OFF forms the opening manipulation of the second switching unit, while the transition from the open condition OFF to the closed condition ON forms the closing manipulation of the second switching unit.

[0076] Preferably, the second switching unit 2 includes one or more trip actuators 25 (which can be of a known type) which are adapted to cause actuation of the movable contact of the switching unit to perform the above-mentioned opening and closing manipulations ( Figures 1 - 2 ).

[0077] As an example, the trip actuator 25 can include an opening coil actuator 25A adapted to cause actuation of the movable contact of the electrode 2A to perform the opening manipulation, and a closing coil actuator 25B adapted to cause actuation of the movable contact of the electrode 2A to perform the closing manipulation.

[0078] The trip actuator 25 can be operatively coupled to an actuating mechanism 29 ( Figure 2 ) which is adapted to actuate the movable contact of the second switching unit. Such an actuating mechanism (which can be of a known type) is conveniently designed to move the movable contact of the second switching unit 2 when tripped by the above-mentioned trip actuator.

[0079] The second switch unit 2 can perform an opening operation or a closing operation when receiving a trip signal T2 from the controller.

[0080] Preferably, the second switch unit 2 can include one or more second drive circuits (not shown), adapted to receive the above-mentioned trip signal T2 and drive a trip actuator 25 according to the second trip signal.

[0081] When driven according to the trip signal T2, the trip actuator 25 trips the above-mentioned actuating mechanism, which actuates the movable contact of the second switch unit to perform the closing operation or the opening operation of the switch unit.

[0082] Preferably, the second switch unit 2 includes one or more contact sensing components 26 adapted to provide a sensing signal S1 indicating the operating condition of the second switch unit 2 to the controller.

[0083] As an example, the sensing component 26 can include a closing microswitch (which can be of a known type) adapted to signal the closed condition ON of the switch unit 2 and an opening microswitch (which can be of a known type) adapted to signal the open condition OFF of the switch unit 2.

[0084] According to the present invention, the switching device 100 is of a draw-out type.

[0085] Therefore, both the first switch unit 1 and the second switch unit 2 can be withdrawn from their normal operating positions to disconnect from the electrical line 50.

[0086] The first switch unit 1 moves reversibly between an inserted condition A where the first pole contact 11 is coupled to the first line terminal 91 and a withdrawn condition B where the first pole contact 11 is decoupled from the first line terminal 91.

[0087] Preferably, when the first switch unit 1 is in the inserted condition A, it has a second pole contact 12 coupled to the third pole contact 23 of the second switch unit 2.

[0088] Preferably, when the first switch unit 1 is in the withdrawn condition B, it has a second pole contact 12 decoupled from the third pole contact 23 of the second switch unit 2.

[0089] The transition from the inserted condition A to the withdrawn condition B forms the withdrawal operation of the first switch unit, while the transition from the withdrawn condition B to the inserted condition B forms the insertion operation of the first switch unit.

[0090] When the first switch unit 1 is in the withdrawn condition B, it can be in a test position where it is still electrically connected to the power stage of the switching device and its low-voltage components are fed by this power stage, or in a fully withdrawn position where it is electrically disconnected from any circuit.

[0091] Preferably, the switching device 100 includes a first carriage (not shown) on which the first switching unit 1 is mounted. Conveniently, such a first carriage is slidably coupled to the support frame of the switching device 100. In this way, both the first switching unit 1 and the first carriage are capable of moving relative to the fixed part of the switching device.

[0092] The switching device 100 includes a first actuation arrangement 7 (which may be of a known type), which is adapted to actuate the first switching unit 1 after being activated by the user (e.g., by a suitable command button) so as to at least perform the extraction action of the switching unit.

[0093] According to a preferred embodiment of the present invention, the first actuation arrangement 7 is adapted to move the first switching unit 1 during the insertion operation of the first switching unit 1 after being activated by the user (e.g., by a suitable command button).

[0094] According to other embodiments of the present invention, the insertion operation of the switching unit 1 can be directly performed by the user, e.g., by using a mechanical tool that can be operatively coupled to a suitable kinematic chain, which is operatively coupled to the switching unit 1 and the support frame of the switching device.

[0095] For the first switching unit 1, the second switching unit 2 can reversibly move between an inserted condition A in which the fourth pole contact 24 is coupled to the second line terminal 92 and a withdrawn condition B in which the fourth pole contact 24 is decoupled from the second line terminal 92.

[0096] Preferably, when the second switching unit 2 is in the inserted condition A, its third pole contact 23 is coupled to the second pole contact 12 of the first switching unit 1.

[0097] Preferably, when the second switching unit 2 is in the withdrawn condition B, its third pole contact 23 is decoupled from the second pole contact 12 of the first switching unit 1.

[0098] The transition from the inserted condition A to the withdrawn condition B forms the extraction operation of the switching unit 2, while the transition from the withdrawn condition B to the inserted condition B forms the insertion operation of the switching unit 2.

[0099] When the switching unit 2 is in the withdrawn condition B, it can be in a test position in which the switching unit 2 is still electrically connected to the power stage of the switching device and its low-voltage components are fed by this power stage, or in a fully withdrawn position in which it is electrically disconnected from any circuit.

[0100] Preferably, the switching device 100 includes a second carriage (not shown) on which the switching unit 2 is mounted. Conveniently, such a second carriage is slidably coupled to the support frame of the switching device 100, so that it is movable relative to the fixed part of the latter (together with the second switching unit 2).

[0101] The switching device 100 includes a second actuation arrangement 8 (which can be of a known type), and the second actuation arrangement 8 is adapted to actuate the second switching unit 2 during the extraction operation of the second switching unit 2 at least after being activated by the user (e.g., via a suitable command button).

[0102] According to some embodiments of the present invention, the second actuation arrangement 8 is adapted to move the second switching unit 2 during the insertion operation of the second switching unit 2 as well after being activated by the user (e.g., via a suitable command button).

[0103] According to some embodiments of the present invention, the insertion operation of the switching unit 2 can be directly performed by the user, e.g., by using a mechanical tool operatively coupled to a suitable kinematic chain, which kinematic chain is operatively coupled to the switching unit 1 and the support frame of the switching device.

[0104] Figure 3 Schematically shows the operating configurations that the switching device 100 can adopt when performing the extraction and insertion operations of the switching units 1, 2.

[0105] According to Configuration #1, both switching units 1, 2 are in the inserted condition.

[0106] According to Configuration #2, the switching unit 1 is in the extracted condition B, while the switching unit 2 is in the inserted condition A. In this case, the switching unit 1 can be in the test position or the fully extracted position as required.

[0107] To switch from Configuration #1 of the switching device to Configuration #2, the extraction operation of only the first switching unit 1 must be performed. To switch from Configuration #2 of the switching device to Configuration #1, the insertion operation of only the first switching unit 1 must be performed.

[0108] According to Configuration #3, the first switching unit 1 is in the inserted condition A, while the second switching unit 2 is in the extracted condition B. In this case, the second switching unit 2 can be in the test position or the fully extracted position as required.

[0109] To switch from Configuration #1 of the switching device to Configuration #3, the extraction operation of only the second switching unit 2 must be performed. To switch from Configuration #3 of the switching device to Configuration #1, the insertion operation of only the second switching unit 2 must be performed.

[0110] According to Configuration #4, both switching units 1, 2 are in the extracted condition. In this case, each of the switching units 1, 2 can be in the test position or the fully extracted position as required.

[0111] To switch from configuration #2 to configuration #4 of the switching device, the extraction operation of the only second switching unit 2 must be performed. To switch from configuration #4 to configuration #2 of the switching device, the insertion operation of the only second switching unit 2 must be performed.

[0112] To switch from configuration #3 to configuration #4 of the switching device, the extraction operation of the only first switching unit 1 must be performed. To switch from configuration #4 to configuration #3 of the switching device, the insertion operation of the only first switching unit 1 must be performed.

[0113] In principle, the switching device 100 can adopt any of the above-mentioned configurations as needed. However, the extraction operations of the switching units 1 and 2 can only be performed when the switching units 1 and 2 are in a certain operating condition. In particular, the extraction operation of the switching unit can only be performed when each of the switching units 1 and 2 is in the open state OFF.

[0114] Generally speaking, the switching units 1 and 2 can include a plurality of additional components arranged at the industrial level according to known types of solutions. Hereinafter, for the sake of brevity, no further structural details will be described for them.

[0115] According to the present invention, the switching device 100 includes a controller 3, which is adapted to control the operation of the switching device 100, especially the switching units 1 and 2.

[0116] According to some embodiments of the present invention ( Figure 1 ), the controller 3 is a self-standing device, which is not enclosed in any of the switching units 1 and 2.

[0117] According to other embodiments of the present invention (not shown), the controller 3 is enclosed in one of the switching units 1 and 2, preferably enclosed in the first switching unit 1.

[0118] Preferably, the controller 3 includes a data processing part 31 adapted to process and provide data or control signals to achieve the requested functionality. Generally speaking, the data processing part 31 can include data processing resources of digital or analog types, such as one or more microprocessors or DSPs.

[0119] Preferably, the controller 3 includes a tripping part 32, which is adapted to interact with the data processing part 31 to generate tripping signals T1 and T2 for controlling the operation of the switching units 1 and 2. Generally speaking, the tripping part 32 can include data processing resources of digital or analog types, such as one or more microprocessors or DSPs.

[0120] Preferably, the controller 3 is adapted to receive and process input commands CM1, CM2, CM3 (e.g., formed by suitable control signals) indicating the desired operating states of the switching devices 100 so as to control the operations of the switching units 1, 2.

[0121] Preferably, the controller 3 includes an interface section 33 which includes one or more input ports adapted to receive the input commands CM1, CM2, CM3.

[0122] Preferably, the switching device 100 includes a man-machine interface 5 communicating with the interface section 33 of the controller 3. The man-machine interface 5 is adapted to provide the input commands CM1, CM2, CM3 when interacting with the user.

[0123] According to other embodiments of the present invention (not shown), the man-machine interface 5 is enclosed in one of the switching units 1 and 2, preferably enclosed in the first switching unit 1.

[0124] According to some embodiments of the present invention, the interface section 33 of the controller 3 is adapted to communicate with a remote computerized device 99 (generally not part of the switching device 100) (e.g., a digital relay). Conveniently, the interface section 33 can receive the input commands CM1, CM2, CM3 from the computerized device 99.

[0125] Generally speaking, the controller 3 and the man-machine interface 5 can be arranged at the industrial level according to known types of hardware solutions. Therefore, hereinafter, for the sake of brevity, no further description of their structural or circuit details will be given.

[0126] In the switching device 100, the closing or opening manipulation of each switching unit is generally performed depending on the desired operating state of the switching device 100.

[0127] The controller 3 is thus conveniently configured to command the execution of the opening or closing manipulation of each switching unit 1, 2 by generating the above-mentioned trip signals T1, T2 in response to receiving the above-mentioned input commands CM1, CM2, CM3.

[0128] In principle, the extraction and insertion manipulations of the switching device 100 can also be performed as needed. However, as mentioned above, the extraction manipulation of each switching unit 1, 2 can only be performed after being activated by the user when the switching unit is in the open condition OFF.

[0129] Preferably, the controller 3 is configured such that if the switch unit 1 is in the closed condition ON, then it prevents the first actuation arrangement 7 (by means of a suitable enabling component - not shown) from moving the first switch unit 1 from the inserted condition A to the withdrawn condition B. The controller 3 thus only enables the first actuation arrangement 7 to move the first switch unit 1 from the inserted condition A to the withdrawn condition B when this switch unit is in the open condition OFF.

[0130] Preferably, the controller 3 is configured such that if the second switch unit 2 is in the closed condition ON, then it also prevents the first actuation arrangement 7 from moving the first switch unit 1 from the inserted condition A to the withdrawn condition B. In this case, the controller 3 only enables the first actuation arrangement 7 to move the first switch unit 1 from the inserted condition A to the withdrawn condition B when both switch units 1, 2 are in the open condition OFF.

[0131] When a leakage current still circulates along the electrodes of the switch unit due to the fact that the second switch unit 2 is in the closed condition ON, this solution allows preventing the withdrawal operation of the first switch unit 1. In this way, it is possible to avoid a discharge phenomenon (due to the interruption of the leakage current) at the pole contacts 11, 12 of the first switch unit, which can be very dangerous for the personnel working on site.

[0132] Preferably, the second actuation arrangement 8 is adapted to move the second switch unit 2 from the inserted condition A to the withdrawn condition B only when the second switch unit 2 is in the open condition OFF.

[0133] Conveniently, the second actuation arrangement 8 incorporates a suitable enabling component (not shown) which prevents the execution of the withdrawal operation of the second switch unit 2 if the second switch device 2 is in the closed condition ON.

[0134] Preferably, the switching device 100 includes a power supply stage 4 which is adapted to receive an external auxiliary power supply V AUX , the external auxiliary power supply V AUX for feeding the internal (electrical or electronic) low - voltage components of the switching device (such as the controller 3, the trip actuator 25, the actuation arrangements 7, 8 and the above - mentioned drive circuits included in the switch units 1, 2).

[0135] Generally, the external auxiliary power supply V AUX is derived from an electrical line 50 through a suitable auxiliary power interface device (not shown). Such an auxiliary power interface device (which is generally not included in the switching device) can be of a known type.

[0136] Preferably, the power supply stage 4 includes one or more drive circuits (not shown) which are adapted to receive the external power supply voltage V AUXAnd provides a charging current for charging a suitable energy storage component (not shown) of the power stage. Conveniently, the energy storage component (e.g., a battery of a capacitor bank) can supply a suitable supply voltage V to the low-voltage internal components of the switching device by drawing electrical energy from the above storage component. S .

[0137] Generally speaking, the power stage 4 can be arranged at the industrial level according to known types of solutions. Therefore, hereinafter, for the sake of brevity, no further structural or circuit details of them will be described.

[0138] Preferably, the controller 3 is configured to implement special control logic to control the operation of the switching device 100 by controlling the operation of the switching units 1, 2.

[0139] According to such control logic, when the first switching unit 1 and the second switching unit 2 are in the inserted condition A, they can only be combined to adopt a specific operation configuration, each configuration corresponding to a predefined given operation state of the switching device 100 ( Figure 4 ).

[0140] Preferably, the controller 3 is configured to control the switching units 1, 2 in such a way that the switching units 1, 2 can be operated in combination, only according to the following operation configurations:

[0141] - The first operation configuration [I], in which both switching units 1, 2 are in the closed condition ON; or

[0142] - The second operation configuration [X], in which the first switching unit 1 is in the open condition OFF and the second switching unit 2 is in the closed condition ON; or

[0143] - The third operation configuration [O], in which both switching units 1, 2 are in the open condition OFF.

[0144] When the switching units 1, 2 operate according to the first operation configuration [I], the line current is allowed to flow through the electrodes 1A, 2A of the switching units 1, 2. Therefore, there is electrical continuity between the first electrical line conductor 51 and the second electrical line conductor 52 of the electrical line 50. Therefore, the first operation configuration [I] of the switching units 1, 2 corresponds to the closed state of the switching device 100.

[0145] When the switching units 1, 2 operate according to the second operation configuration [X], since the first switching unit 1 is in the open condition OFF, line current is not allowed to flow along the electrodes 1A, 2A of the switching units 1, 2. The first line conductor 51 and the second line conductor 52 of the electrical line 50 are thus disconnected. However, when the second switching unit 2 is in the closed condition ON, there is no galvanic insulation between the line conductors 51, 52, and the leakage current affecting the solid-state switch 10 can still flow along the electrodes 1A, 2A. The second operation configuration [X] of the switching units 1, 2 corresponds to the standby state of the switching device 100, which is between the closed state and the open state.

[0146] When the switching units 1, 2 operate according to the third operation configuration [O], since both switching units 1 are in the open condition OFF, line current and possible leakage current are not allowed to flow along the electrodes 1A, 2A of the switching units 1, 2. The first line conductor 51 and the second line conductor 52 of the electrical line 50 are disconnected, and there is galvanic insulation between the line conductors. Thus, the third operation configuration [O] of the switching units 1, 2 corresponds to the open state of the switching device 100.

[0147] Generally, the controller 3 is configured to command the switching units 1, 2 to switch from one operation configuration to another in response to receiving the above input commands CM1, CM2, CM3 indicating the desired operation state for the switching device 100.

[0148] However, according to the control logic implemented by the controller 3, any transition between the operation configurations of the switching units 1, 2 must always involve the second operation configuration [X], which corresponds to the standby state of the switching device 100 ( Figure 4 ).

[0149] In other words, the controller 3 is configured to control the switching units 1, 2 in such a way as to prevent any direct transition between the first operation configuration [I] and the third configuration [O] of the switching units 1, 2 ( Figure 4 ).

[0150] Preferably, when the switching units 1, 2 are in the first operation configuration [I] (corresponding to the closed state of the switching device 100), the controller 3 can command the switching units 1, 2 to switch to the second operation configuration [X] (corresponding to the standby state of the switching device 100).

[0151] In fact, according to the control logic implemented by the controller 3, the switching units 1, 2 can only switch from the first operation configuration [I] to another operation configuration through the second operation configuration [X].

[0152] When it is in the closed state (the first operating configuration [I] of switch units 1 and 2), the switching device 100 can be switched to another operating state only through the standby state (the second operating configuration [X] of switch units 1 and 2).

[0153] Preferably, when switch units 1 and 2 are in the second operating configuration [X] (the standby state corresponding to switch unit 100), the controller 3 can command switch units 1 and 2 to switch to the first operating configuration [I] (corresponding to the closed state of the switching device 100) or to the third operating configuration [O] (corresponding to the open state of the switching device 100).

[0154] In fact, according to the control logic implemented by the controller 3, switch units 1 and 2 can be switched from the second operating configuration [X] to the first operating configuration [I] or the third operating configuration [O].

[0155] When it is in the standby state (the second operating configuration [X] of switch units 1 and 2), the switching device 100 can be switched in the closed state (the first operating configuration [I] of switch units 1 and 2) or in the open state (the third operating configuration [O] of switch units 1 and 2).

[0156] Preferably, when switch units 1 and 2 are in the third operating configuration [O] (corresponding to the open state of the switching device 100), the controller 3 can command switch units 1 and 2 to switch to the second operating configuration [X] (corresponding to the standby state of the switching device 100).

[0157] In fact, according to the control logic implemented by the controller 3, switch units 1 and 2 can be switched from the third operating configuration [O] to another operating configuration only through the second operating configuration [X].

[0158] When it is in the open state (the third operating configuration [O] of switch units 1 and 2), in response to receiving input commands CM1, CM2 indicating a desired different operating state, the switching device 100 can be switched to another operating state only through the standby state (the second operating configuration [X] of switch units 1 and 2).

[0159] Configure the above control logic such that the extraction manipulation of each of switch units 1 and 2 can be performed only when the switch unit is in the open condition OFF and is activated by the user.

[0160] Preferably, if the first switch unit 1 and the second switch unit 2 operate combinatorially according to the first operating configuration [I], then the controller 3 is configured to prevent the extraction manipulation of the first switch unit 1 (by disabling the first actuation arrangement 7 as mentioned above).

[0161] Preferably, the controller 3 is configured to prevent the withdrawal operation of the first switch unit 1 even when the second switch unit 2 is in the closed condition ON. In this case, the controller 3 is configured to prevent the withdrawal operation of the first switch unit 1 even when the first switch unit 1 and the second switch unit 2 operate in combination according to the second operation configuration [X], and the controller 3 is configured to enable the withdrawal operation of the first switch unit 1 only when the first switch unit 1 and the second switch unit 2 operate in combination according to the third operation configuration [O].

[0162] Preferably, the second actuation arrangement 8 is adapted to perform the withdrawal operation of the second switch unit 2 only when the second switch unit 2 is in the open condition OFF. In this case, the controller 3 is configured to enable the withdrawal operation of the first switch unit 1 only when the first switch unit 1 and the second switch unit 2 operate in combination according to the third operation configuration [O].

[0163] Conveniently, the above control logic is designed to take into account the possible fault conditions of the power stage 4.

[0164] According to the present invention, the switch unit 2 is designed such that, upon the intervention of the user, when the opening operation commanded by the controller 3 (e.g., when implementing the above-mentioned control logic) cannot be performed for any reason (e.g., because the switching device cannot receive or utilize an external auxiliary power supply to power its low-voltage internal components or because of a fault in the trip actuator 25 or the drive circuit operably associated with the trip actuator), the switch unit 2 can be forced to perform the opening operation in an emergency situation.

[0165] Referring again to Figure 2 , the switch unit 2 includes an emergency control arrangement 27 that can be activated by the user to cause the second switch unit 2 to perform an opening operation, i.e., to switch from the closed condition ON to the opening operation OFF.

[0166] Conveniently, when the emergency control arrangement 27 is activated by the user with the second switch unit 2 in the closed condition ON, the emergency control arrangement 27 trips the actuating mechanism 29 of the second switch unit 2 so that the movable contact 202 of the switch unit moves in a manner to perform the above-mentioned opening operation.

[0167] In response to the tripping of the emergency control arrangement 27, the actuating mechanism 29 moves the movable contact 202 from a position coupled to the fixed contact 201 to a position decoupled from the fixed contact, so that the second switch unit 2 switches from the closed condition ON to the open condition OFF.

[0168] The emergency control arrangement 27 includes an emergency command button 271 that can preferably be operated by the user from a rest position to an activation position.

[0169] Preferably, the emergency control arrangement 27 includes a tripping element 272 operatively coupled to a command button 271.

[0170] When the second switch unit 2 is in the closed condition ON, the movement of the command button 271 to the activated position (applied by the user) trips the activation mechanism 29. The latter causes the movable contact 202 to decouple from the corresponding fixed contact 203, so that the second switch unit 2 performs an opening operation.

[0171] According to the invention, the command button 271 is not normally used by the user because it is covered by one or more parts of the second switch unit 2, preferably by one or more panels of the wall 28 (usually the front wall) of the second switch unit 2.

[0172] Therefore, the user can only access the command button 271 when one or more structural parts 28A, 28B of the second switch unit 2 are removed.

[0173] Preferably, the second switch unit 2 includes a first protection panel 28A covering the emergency command button 271 at the wall 28 (preferably the front wall). Thus, after removing the first protection panel from the second switch unit 2, the user can access the command button 271.

[0174] Preferably, the second switch unit 2 includes a second protection panel 28B covering the first protection panel 28A at the same wall 28. Thus, after removing the first protection panel and the second protection panel from the second switch unit 2, the user can access the command button 271.

[0175] Preferably, the emergency control arrangement 27 includes a signal component 273 adapted to provide the user with an optical signal L indicating the operating condition of the second switch unit 2, and more preferably indicating that the second switch unit 2 is in the closed condition ON.

[0176] Preferably, the signal component 273 may include a sensing device (e.g., a microswitch) adapted to detect the position of the movable contact 202 of the second switch unit 2 and an LED device operatively coupled to the sensing device and adapted to emit the optical signal L in response to receiving a signal from the sensing signal indicating that the movable contact 202 is in the coupled position with the corresponding fixed contact 201.

[0177] Conveniently, the optical signal L emitted by the signal component 273 is always visible to the user without removing a part of the switch unit 2.

[0178] When the signal component 273 (especially its LED device) is arranged on the same wall 28 where the command button 271 is located ( Figure 2The protective panels 28A, 28B covering the emergency command button 271 are designed (as shown in []) in such a way as not to hide the optical signal L emitted by the signal component 273 (for example, provided with a suitable window).

[0179] Generally speaking, the protective panels 28A, 28B and the signal component 273 can be designed at the industrial level according to known types of solutions. Hereinafter, for the sake of brevity, no further structural details thereof will be described.

[0180] Figure 5A , 5B Figures 5B, 5C schematically show how a user activates the emergency control arrangement 27 of the second switch unit 2 in such a way as to force the second switch unit 2 to perform an opening operation.

[0181] When the opening operation of the second switch unit 2 fails, the user can understand that this switch unit is still in the closed condition ON by observing the optical signal L emitted by the signal component 273 ( Figure 5A ).

[0182] The user can remove the second protective panel 28B at a suitable wall 28 (usually the front wall) of the second switch unit 2. In this way, the user can access the first protective panel 28A ( Figure 5B ).

[0183] The user can remove the first protective panel 28A so as to be able to access the command button 271. At this stage, the user can operate (for example, press) the command button 271 in such a way as to make the second switch unit 2 perform an opening operation.

[0184] Preferably, the emergency control arrangement 27 includes a sensing component 274, which is adapted to provide an alarm signal SA indicating the removal condition of the above-mentioned first protective panel 28A to the controller 3.

[0185] Preferably, if the first switch unit 1 is in the closed condition ON, then the controller 3 commands the first switch unit 1 to switch to the open condition OFF in response to receiving the alarm signal SA.

[0186] Preferably, if the first switch unit 1 is in the open condition OFF, then the controller 3 prevents the first switch unit 1 from switching to the closed condition ON in response to receiving the alarm signal SA.

[0187] This solution is very useful for improving the operating safety of the switching device. In fact, if the user is enabled to access the emergency control arrangement 27 for any reason, then the controller 3 provides for the first switching unit 1 to be placed or maintained in a safe condition (i.e., in the open condition OFF). In this way, if the user is enabled to access the emergency control arrangement 27, then the possible dangerous withdrawal manoeuvre of the second switching unit 2 (especially when the first switching unit 1 is in the closed condition ON) is automatically prevented.

[0188] The switching device 100 of the present invention provides relevant advantages over the available corresponding solutions of the prior art.

[0189] In the switching device 100, the electromechanical switching unit 2 is provided with an emergency control arrangement 27 which allows the switching unit to be forced to perform an opening manoeuvre in the event of failure of a normal opening manoeuvre for any reason (e.g., due to lack of auxiliary power).

[0190] This solution prevents the execution of the withdrawal manoeuvre of the second switching unit 2 in the presence of a leakage current which may still circulate if the second switching unit 2 is in the closed condition ON (even if the switching unit 1 is in the open condition OFF and the solid-state switch is in the blocking state).

[0191] According to one aspect of the invention, the controller 3 of the switching device is configured to control the switching units 1, 2 in such a way that, in addition to the closed state (first configuration [I] of the switching units 1, 2) and the open state (third configuration [O] of the switching units 1, 2), the switching device 100 can also assume a standby state (second configuration [X] of the switching units).

[0192] When the switching device 100 has to perform an opening manoeuvre (i.e., the transition from the closed state to the open state) or a closing manoeuvre (i.e., the transition from the open state to the closed state), this solution allows the time synchronization constraints between the switching units 1, 2 to be relaxed.

[0193] It has been demonstrated that the adoption of the emergency control arrangement 27 foreseen by the present invention is worthwhile for safely implementing such control logic.

[0194] When this switching operation commanded by the controller 3 fails for any reason, the user can activate the emergency control arrangement 27 to force the switching device to switch from the standby state (second configuration [X] of the switching units 1, 2) to the open state (third configuration [O] of the switching units 1, 2).

[0195] The switching device 100 can thus operate according to a robust control logic which allows its overall efficiency and safety to be improved.

[0196] The switching device 100 is relatively easy to produce on an industrial scale and can be manufactured at a competitive cost compared to similar devices of the prior art.

Claims

1. A switching device (100) for a distribution network, characterized in that, Comprising: - One or more first circuit terminals and second circuit terminals (91, 92), respectively capable of being electrically connected to corresponding first circuit conductors and second circuit conductors (51, 52) of an electrical circuit; - A first switch unit (1) having one or more first electrodes (1A), each first electrode including a first pole contact (11), a second pole contact (12) capable of being electrically connected to the corresponding first circuit terminal (91), and one or more solid-state switches (10) electrically connected to the first pole contact and the second pole contact and adapted to operate in a conducting state or a blocking state to allow or interrupt current flow, wherein the first switch unit is capable of reversibly switching between a closed condition (ON) in which the solid-state switches are in a conducting state and an open condition (OFF) in which the solid-state switches are in a blocking state, wherein the first switch unit is capable of reversibly moving between an inserted condition (A) in which the first pole contact is coupled to the first circuit terminal (91) and a withdrawn condition (B) in which the first pole contact is decoupled from the first circuit terminal; - A second switch unit (2) having one or more second electrodes (2A), each second electrode including a third pole contact (23) capable of being electrically connected to the corresponding second pole contact (12) of the first switch unit (1), a fourth pole contact (24) capable of being electrically connected to the corresponding second circuit terminal (92), and an electrical contact (20) electrically connected to the third pole contact and the fourth pole contact and adapted to operate in a coupled state or a decoupled state to allow or interrupt current flow, wherein the second switch unit is capable of reversibly switching between a closed condition (ON) in which the electrical contact is in a coupled state and an open condition (OFF) in which the electrical contact is in a decoupled state, wherein the second switch unit is capable of reversibly moving between an inserted condition (A) in which the fourth pole contact is coupled to the second circuit terminal (92) and a withdrawn condition (B) in which the fourth pole contact (24) is decoupled from the second circuit terminal; - A controller (3), adapted to control the operation of the switching device; The second switch unit (2) includes an emergency control arrangement (27) capable of being activated by a user to switch the second switch unit (2) from the closed condition (ON) to the open condition (OFF), the emergency control arrangement including an emergency command button (271) operable by the user, and the user can access the emergency command button after removing one or more structural parts (28A, 28B) of the second switch unit.

2. The switching device according to claim 1, characterized in that The second switch unit (2) includes a first protection panel (28A) covering the emergency command button (271), and the user can access the emergency command button after removing the first protection panel from the second switch unit.

3. The switching device according to claim 2, characterized in that The second switch unit (2) includes a second protection panel (28B) covering the first protection panel (28A), and the user can access the emergency command button (271) after removing the first protection panel and the second protection panel from the second switch unit.

4. The switching device according to any one of claims 1 to 3, characterized in that, Each second electrode (2A) of the second switching unit (2) includes at least a fixed electrical contact (201) and a movable electrical contact (202). The second switching unit includes an actuating mechanism (29) adapted to reversibly move one or more movable contacts of the second switching unit between a position coupled to a corresponding fixed contact of the second switching unit and a position decoupled from the fixed contact. The emergency control arrangement (27) is adapted to trip the actuating mechanism (29) to move the movable contact after being activated by a user when the second switching unit is in the closed condition (ON). The actuating mechanism (29) is adapted to move the movable contact from a position coupled to the fixed contact to a position decoupled from the fixed contact in response to the tripping of the emergency control arrangement, so that the second switching unit switches from the closed condition (ON) to the open condition (OFF).

5. The switching device according to claim 4, characterized in that The emergency control arrangement (27) includes a tripping element (272) operatively coupled to the emergency command button (271). When the emergency command button is operated by a user to the activated position, the tripping element is adapted to trip the actuating mechanism (29).

6. The switching device according to any one of claims 1 to 3, characterized in that The emergency control arrangement (27) includes a signal component (273) adapted to provide a light signal (L) to the user indicating the operating condition of the second switching unit (2).

7. The switching device according to claim 2 or 3, characterized in that The emergency control arrangement (27) includes a sensing component (274) adapted to provide an alarm signal (SA) indicating the removal condition of the first protection panel (28A) to the controller (3).

8. The switching device according to claim 7, characterized in that The controller (3) is configured to command the first switching unit (1) to switch from the closed condition (ON) to the open condition (OFF) in response to receiving the alarm signal (SA) when the first switching unit is in the closed condition (ON).

9. The switching device according to claim 7, characterized in that, The controller (3) is configured to prevent the first switching unit (1) from switching to the closed condition (ON) in response to receiving the alarm signal (SA) when the first switching unit is in the open condition (OFF).

10. The switching device according to any one of claims 1 to 3, characterized in that, The controller (3) is configured to control the first switching unit and the second switching unit (1, 2) such that the first switching unit and the second switching unit operate combinatorially according to the following operating configurations: - A first operating configuration ([I]) corresponding to the closed state of the switching device, in which the first switching unit and the second switching unit (1, 2) are both in the closed condition (ON); Or - A second operating configuration ([X]) corresponding to the standby state of the switching device, in which the first switching unit (1) is in the open condition (OFF) and the second switching unit (2) is in the closed condition (ON); Or - A third operating configuration ([O]) corresponding to the open state of the switching device, in which the first switching unit and the second switching unit (1, 2) are both in the open condition (OFF).

11. The switching device according to any one of claims 1 to 3, characterized in that, The controller (3) includes an interface section (33), which includes one or more input ports adapted to receive input commands (CM1, CM2, CM3) indicating a desired operating state of the switching device.

12. The switching device according to claim 11, characterized in that, It includes a human-machine interface (5) communicating with the interface section (33), and the human-machine interface is adapted to provide the input commands (CM1, CM2, CM3) when interacting with the user.

13. The switching device according to claim 11, characterized in that, The interface section (33) is capable of receiving the input commands (CM1, CM2, CM3) from a remote computerized device (9).

14. The switching device according to any one of claims 1 to 3, characterized in that, The controller (3) is included in the first switch unit (1).

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