Extractable type hybrid switchgear

Abstract

The present disclosure relates to an extractable type hybrid switchgear. A switchgear for an electrical distribution network, comprising: - an extractable first switch unit having one or more first electrodes; - an extractable second switch unit having one or more second electrodes and electrically connected in series with the first switch unit; - a controller implementing a control strategy for increasing the safety of the extraction manoeuvre of the first switch unit and the second switch unit.

Description

Technical Field

[0001] This invention relates to switching devices for power distribution networks, such as circuit breakers or other devices of the same type. Background Technology

[0002] As is well known, low-voltage switchgear is used in circuits or power grids to allow for the proper operation of specific sections of the circuit or power grid. For example, these devices can be used to ensure the availability of the nominal current required by certain utilities, to enable electrical loads (especially circuit breakers) to be properly plugged in and disconnected, and to protect the power grid and installed electrical loads from fault events such as overloads and short circuits.

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

[0004] While these devices have proven to be very robust and reliable, the second switching device in DC applications exhibits a relatively long interruption time, primarily at relatively high voltages (between 1-1.5kV DC). Therefore, the arcing that typically occurs between the electrical contacts when disconnected can persist for a relatively long time. This can cause severe wear on the electrical contacts and a significant reduction in operational reliability and electrical durability.

[0005] To overcome these technical problems, they have been designed as switching devices (also known as "SSCB" – solid-state circuit breakers) that include switching units. For each electrode, the switching unit has one or more solid-state switches, i.e., semiconductor-based transistors or thyristors, which are adapted to operate in the on state or the off state to allow or interrupt the flow of current.

[0006] The main advantage of SSCBs is that, because they perform the disconnection operation without forming an electric arc, they possess potentially unrestricted electrical withstand capability. Furthermore, their interruption time is significantly shorter compared to that of electromechanical switching devices.

[0007] A significant drawback of SSCBs is that they generally cannot provide electrical insulation between the conductors to which they are connected. In fact, when voltage is applied to the power terminals of a solid-state switch (e.g., the collector and emitter terminals of an IGBT), leakage current typically flows even when the switch is in the blocking state.

[0008] Recently, switching devices including SSCB switch units and electromechanical switch units connected in series have been developed.

[0009] These switching devices (often referred to as "hybrid switching devices") allow the use of all the advantages offered by SSCBs in terms of reliability and reduced downtime, while also allowing for current insulation between the line conductors to which they are connected.

[0010] As is known, many hybrid switching devices are of the "withdrawable" type. In this case, both the SSCB and the second switching unit are movable relative to a fixed section of the switching device. Specifically, each switching unit is mounted on a carriage in a manner that allows it to reversibly move between an insertion position and a withdrawal position relative to a fixed section of the switching device.

[0011] In terms of efficiency and safety, withdrawable hybrid switchgear offers further advantages. In fact, both of the aforementioned switch units can be placed in the withdrawable position, allowing for easy field testing or maintenance interventions with the switch unit completely disconnected from the line conductors.

[0012] However, there are still some aspects of these switching devices that need improvement, particularly concerning the coordinated control of the SSCB switching unit and the electromechanical switching unit during operation.

[0013] Current control strategies do not allow these switching devices to operate in a completely safe manner in some situations (such as when they cannot receive an external auxiliary power supply to feed their internal low-voltage components, such as electronic circuits, actuators, or controllers). Summary of the Invention

[0014] The main objective of this invention is to provide a removable hybrid switch device that makes it possible to overcome or mitigate the technical problems of the prior art mentioned above.

[0015] Within this objective, the object of the present invention is to provide a switching device that ensures a high level of safety and efficiency during operation.

[0016] Another object of the present invention is to provide a switching device that can be easily controlled in operation without the need for complex and expensive control resources.

[0017] Another object of the present invention is to provide a switching device that is relatively easy and inexpensive to manufacture at an industrial level.

[0018] According to the present invention, this objective and these objectives, as well as other objectives that will become clear from the following description and drawings, are achieved by a switching device according to claim 1 and related dependent claims listed below.

[0019] The switching device according to the present invention includes:

[0020] - One or more first line terminals and second line terminals, the one or more first line terminals and second line terminals being intended to be electrically connected to corresponding first line conductors and second line conductors of an electrical line, respectively;

[0021] - A first switching unit having one or more first electrodes, each first electrode including a first electrode contact, a second electrode contact, and one or more solid-state switches, the first electrode contact being intended to be electrically connected to a corresponding first line terminal, the one or more solid-state switches being electrically connected to the first electrode contact and the second electrode contact and adapted to operate in an ON state or an OFF state to allow or interrupt current flow.

[0022] The first switching unit can reversibly switch between a closed state where the solid-state switch is in a conducting state and an open state where the solid-state switch is in a blocking state.

[0023] The first switching unit is reversibly movable between the insertion state in which the first pole contact is coupled to the first line terminal and the withdrawal state in which the first pole contact is decoupled from the first line terminal.

[0024] - A second switching unit having one or more second electrodes, each second electrode including a third electrode contact, a fourth electrode contact, and an electrical contact, the third electrode contact being intended to be electrically connected to a corresponding second electrode contact of a first switching unit, the fourth electrode contact being intended to be electrically connected to a corresponding second line terminal of the first switching unit, the electrical contact being electrically connected to the third electrode contact and the fourth electrode contact and adapted to operate in a coupled or uncoupled state to allow or interrupt current flow.

[0025] The second switching unit can reversibly switch between a closed state where the electrical contact is in a coupled state and an open state where the electrical contact is in a decoupled state.

[0026] The second switching unit is reversibly movable between the insertion state in which the fourth pole contact is coupled to the second line terminal and the withdrawal state in which the fourth pole contact is decoupled from the second line terminal.

[0027] According to the present invention, the controller of the switching device is configured to control the first switching unit and the second switching unit such that when the power supply stage experiences a fault condition, both the first switching unit and the second switching unit are in an open state.

[0028] Preferably, the controller is configured to command the first switching unit and the second switching unit to switch to or remain in an off state in response to receiving a sensing signal indicating a fault condition of the power supply stage.

[0029] Preferably, the switching device includes a power supply sensing component adapted to provide the controller with a sensing signal indicating the operating status of the power supply stage (4).

[0030] According to an aspect of the invention, the controller of the switching device is configured to control the operating states of the first switching unit and the second switching unit, such that the first switching unit and the second switching unit operate in combination according to the following operating configuration:

[0031] - A first operational configuration corresponding to the closed state of the switching device, wherein both the first switching unit and the second switching unit are in the closed state; or

[0032] - A second operating configuration corresponding to the standby state of the switching device, wherein the first switching unit is in an open state and the second switching unit is in a closed state; or

[0033] - A third operating configuration corresponding to the off state of the switching device, wherein both the first switching unit and the second switching unit are in the off state.

[0034] The controller is configured to control the first switching unit and the second switching unit such that when the power supply stage experiences a fault condition, the first switching unit and the second switching unit are in the third operating configuration.

[0035] Preferably, the controller is configured to command the first switching unit and the second switching unit to switch to or remain in the third operating configuration in response to receiving a sensing signal indicating a fault condition of the power supply stage.

[0036] Preferably, when the first switching unit and the second switching unit operate in combination according to the first operating configuration, the controller, in response to receiving a sensing signal indicating a fault condition of the power supply stage, commands the first switching unit and the second switching unit to switch to the second operating configuration and then to the third operating configuration.

[0037] Preferably, when the first switching unit and the second switching unit operate in combination according to the second operating configuration, the controller commands the first switching unit and the second switching unit to switch to the third operating configuration in response to receiving a sensing signal indicating a fault condition of the power supply stage.

[0038] Preferably, when the first switching unit and the second switching unit operate in combination according to the third operating configuration, the controller commands the first switching unit and the second switching unit to remain in the third operating configuration in response to receiving a sensing signal indicating a fault condition of the power supply stage.

[0039] According to an aspect of the invention, the switching device includes a first actuation arrangement adapted to actuate the first switching unit at least during a withdrawal operation of the first switching unit when activated by a user.

[0040] According to an aspect of the invention, the switching device includes a second actuation arrangement (8) adapted to actuate the second switching unit at least during the withdrawal operation of the second switching unit when activated by a user.

[0041] According to an aspect of the invention, the controller of the switching device includes an interface section comprising one or more input ports adapted to receive input commands indicating a desired operating state of the switching device.

[0042] Preferably, the switching device includes a human-machine interface that communicates with the interface segment. The human-machine interface is adapted to provide the input command after interaction with the user.

[0043] Preferably, the interface segment is capable of receiving the input command from a remote computerized device.

[0044] According to an aspect of the invention, the controller of the switching device is included in the first switching unit. Attached Figure Description

[0045] Other features and advantages of the invention will become more apparent from the description of preferred, but not exclusive, embodiments illustrated in the accompanying drawings by way of example only and not limitation, wherein:

[0046] Figure 1 A switching device according to the present invention is schematically shown;

[0047] Figures 2-6 The operation of the switching device according to the present invention is illustrated schematically. Detailed Implementation

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

[0049] The switchgear 100 is particularly suitable for installation in low-voltage power grids or systems. However, it can also be successfully used in medium-voltage power grids or systems.

[0050] For the purposes of this invention, the term “low voltage” (LV) refers to operating voltages below 1 kV AC and 1.5 kV DC, while the term “medium voltage” (MV) refers to higher operating voltages, up to tens of kV, such as up to 72 kV AC and 100 kV DC.

[0051] Generally, the switching device 100 is intended to be electrically connected to the 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 section of a power transmission or generation system or grid) and one or more second line conductors 52 that can be connected to an equivalent electrical load (e.g., a section of a power system or device or grid).

[0052] In the embodiment shown in the cited figure, the electrical line 50 is three-phase. However, in principle, it can include a different number of 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 corresponding first line conductors 51 and second line conductors 52 of the electrical line 50, respectively.

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

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

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

[0057] The number of electrodes in the first switching unit can be varied as needed. In the embodiment shown in the referenced figures, the first switching unit is three-phase and includes three electrodes. However, according to other embodiments of the invention (not shown), the first switching unit may 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 to the corresponding electrode of the second switching unit 2.

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

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

[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] A solid-state switch 10 for each electrode 1A is electrically connected between electrode contacts 11 and 12, for example, according to a series configuration or other more complex circuit configuration of known types.

[0063] In operation, the first switching unit 1 can reversibly switch between a closed state ON in which the solid-state switch 10 of electrode 1A is in a conducting state and an open state OFF in which the solid-state switch 10 of electrode 1A is in a blocking state.

[0064] When the first switching unit 1 is in the closed state (ON), line current is allowed to flow along electrode 1A. Conversely, when the switching unit 1 is in the open state (OFF), line current cannot flow along electrode 1A. However, the possible leakage current that typically affects a solid-state switch in the blocking state can still circulate.

[0065] The transition from the closed state ON to the open state OFF constitutes the disconnection operation of the first switching unit, while the transition from the open state OFF to the closed state ON constitutes the closing operation of the first switching unit.

[0066] The first switching unit 1 can perform a disconnection or closing operation when it receives the first trip signal T1 from the controller 3.

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

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

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

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

[0071] Therefore, each electrode 2A includes a third contact 23 intended to be electrically connected to the corresponding second contact 12 of the first switching unit 1 and a fourth 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 operate in a coupled or decoupled state to allow or interrupt current flow. 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 can reversibly switch between a closed state ON in which the electrical contact 20 of electrode 2A is in a coupled state and an open state OFF in which the electrical contact 20 of electrode 2A is in a decoupled state.

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

[0075] The transition from the closed state ON to the open state OFF constitutes the disconnection operation of the second switching unit, while the transition from the open state OFF to the closed state ON constitutes the closing operation of the second switching unit.

[0076] Preferably, the second switching unit 2 includes one or more trip actuators 25 (which may be of a known type) adapted to actuate the movable contacts of the switching unit to perform the aforementioned opening and closing operations.

[0077] As an example, the trip actuator 25 may include a disconnecting coil actuator and a closing coil actuator, the disconnecting coil actuator being adapted to actuate a movable contact of electrode 2A to perform a disconnecting operation, and the closing coil actuator being adapted to actuate a movable contact of electrode 2A to perform a closing operation.

[0078] The trip actuator 25 can be operatively coupled to a suitable actuation mechanism (not shown) adapted to actuate the movable contact of the second switching unit. Such an actuation mechanism (which may be of a known type) is conveniently designed to move the movable contact of the second switching unit 2 upon tripping by the trip actuator mentioned above.

[0079] The second switching unit 2 can perform a disconnection or closing operation when it receives a trip signal T2 from the controller.

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

[0081] When driven according to the trip signal T2, the trip actuator 25 trips the aforementioned actuation mechanism, which actuates the movable contact of the second switching unit to perform the closing or opening operation of the second switching unit.

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

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

[0084] According to the present invention, the switching device 100 is of the withdrawable 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 circuit 50.

[0086] The first switching unit 1 is reversibly movable between an insertion state A in which the first pole contact 11 is coupled to the first line terminal 91 and an extraction state B in which the first pole contact 11 is decoupled from the first line terminal 91.

[0087] Preferably, when in insertion state A, the first switching unit 1 couples the second pole contact 12 with the third pole contact 23 of the second switching unit 2.

[0088] Preferably, when in the withdrawn state B, the first switching unit 1 decouples the second pole contact 12 from the third pole contact 23 of the second switching unit 2.

[0089] The transition from insertion state A to withdrawal state B constitutes the withdrawal operation of the first switching unit, while the transition from withdrawal state B to insertion state A constitutes the insertion operation of the first switching unit.

[0090] When in the withdrawn state B, the first switch unit 1 can be in the test position or in the fully withdrawn position. In the test position, the first switch unit 1 is electrically disconnected from the electrical line 50, but is still electrically connected to the power supply stage of the switching device, and its low-voltage components are fed by the power supply stage. In the fully withdrawn position, the first switch unit 1 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, this 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 movable relative to a fixed section of the switching device.

[0092] The switching device 100 includes a first actuation arrangement 7 (which may be of a known type) adapted to actuate a first switching unit 1 upon activation by a user (e.g., via an appropriate command button) to perform at least a withdrawal operation of the switching unit.

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

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

[0095] Like the first switching unit 1, the second switching unit 2 is reversibly movable between an insertion state A in which the fourth pole contact 24 is coupled to the second line terminal 92 and a withdrawal state B in which the fourth pole contact 24 is decoupled from the second line terminal 92.

[0096] Preferably, when in insertion state A, the second switching unit 2 couples the third pole contact 23 with the second pole contact 12 of the first switching unit 1.

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

[0098] The change from insertion state A to withdrawal state B constitutes the withdrawal operation of switch unit 2, while the change from withdrawal state B to insertion state B constitutes the insertion operation of switch unit 2.

[0099] When in withdrawn state B, switch unit 2 can be in the test position or in the fully withdrawn position. In the test position, switch unit 2 is electrically disconnected from electrical line 50, but is still electrically connected to the power supply stage of the switching device, and its low-voltage components are fed by the power supply stage. In the fully withdrawn position, switch unit 2 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, this second carriage is slidably coupled to the support frame of the switching device 100, thereby allowing it to move relative to a fixed section of the switching device 100 (together with the second switching unit 2).

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

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

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

[0104] Figure 2 This schematically illustrates the operational configurations that the switching device 100 can take when performing the withdrawal and insertion operations of switching units 1 and 2.

[0105] According to configuration #1, both switch units 1 and 2 are in the insertion state.

[0106] According to configuration #2, switch unit 1 is in the withdrawn position (B), while switch unit 2 is in the inserted position (A). In this case, switch unit 1 can be in the test position or the fully withdrawn position as needed.

[0107] To switch from configuration #1 to configuration #2 of the switching device, a unique withdrawal operation of the first switching unit 1 must be performed. To switch from configuration #2 to configuration #1 of the switching device, a unique insertion operation of the first switching unit 1 must be performed.

[0108] According to configuration #3, the first switch unit 1 is in the insertion state A, while the second switch unit 2 is in the withdrawal state B. In this case, the second switch unit 2 can be in the test position or the fully withdrawn position as needed.

[0109] To switch from configuration #1 to configuration #3 of the switching device, a unique withdrawal operation of the second switching unit 2 must be performed. To switch from configuration #3 to configuration #1 of the switching device, a unique insertion operation of the second switching unit 2 must be performed.

[0110] According to configuration #4, both switch units 1 and 2 are in the withdrawn state. In this case, each of switch units 1 and 2 can be in the test position or the fully withdrawn position as needed.

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

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

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

[0114] Generally, switch units 1 and 2 may include multiple additional components arranged at an industrial level according to known types of solutions. For the sake of brevity, they will not be described in further structural detail below.

[0115] According to the present invention, the switching device 100 includes a controller 3 adapted to control the operation of the switching device 100 (specifically the first switching unit 1 and the second switching unit 2).

[0116] According to some embodiments of the present invention ( Figure 1 The controller 3 is a stand-alone device and is not enclosed within either of the switching units 1 or 2.

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

[0118] Preferably, the controller 3 includes a data processing section 31 adapted to process and provide data or control signals to achieve the requested function. Generally, the data processing section 31 may include digital or analog data processing resources, such as one or more microprocessors or DSPs.

[0119] Preferably, the controller 3 includes a trip section 32 adapted to interact with the data processing section 31 to generate trip signals T1 and T2 for controlling the operation of the switching units 1 and 2. Generally, the trip section 32 may include digital or analog data processing resources, 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 appropriate control signals) that indicate the desired operating state of the switching device 100, so as to control the operation 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 input commands CM1, CM2, CM3.

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

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

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

[0125] The controller 3 and human-machine interface 5 can be deployed at an industrial level based on known types of hardware solutions. Therefore, for the sake of brevity, they will not be described in further structural or circuit details below.

[0126] In the switching device 100, the closing or opening operation 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, in response to receiving the input commands CM1, CM2, CM3 mentioned above, command the execution of the opening or closing operation of each switching unit 1, 2 by generating the trip signals T1, T2 mentioned above.

[0128] In principle, the withdrawal and insertion operations of the switch unit 100 can also be performed as needed. However, as mentioned above, the withdrawal operation of the switch unit can only be performed when it is activated by the user, and each switch unit 1, 2 is in the OFF state.

[0129] Preferably, the controller 3 is configured to prevent the first actuation arrangement 7 (by a suitable enabling component - not shown) from moving the first switch unit 1 from the insertion state A to the withdrawal state B if the switch unit 1 is in the closed state ON. The controller 3 therefore only causes the first actuation arrangement 7 to move the first switch unit 1 from the insertion state A to the withdrawal state B when the switch unit is in the open state OFF.

[0130] Preferably, the controller 3 is configured to prevent the first actuation arrangement 7 from moving the first switch unit 1 from the insertion state A to the withdrawal state B if the second switch unit 2 is in the closed state ON. In this case, the controller 3 enables the first actuation arrangement 7 to move the first switch unit 1 from the insertion state A to the withdrawal state B only when both switch units 1 and 2 are in the open state OFF.

[0131] This solution allows for the prevention of withdrawal of the first switching unit 1 when leakage current continues to circulate along the electrodes of the switching unit due to the fact that the second switching unit 2 is in the closed (ON) state. In this way, it is possible to avoid discharge phenomena (due to the interruption of leakage current) at the pole contacts 11 and 12 of the first switching unit, which could be very dangerous for personnel operating in the field.

[0132] Preferably, the second actuation arrangement 8 is adapted to move the second switch unit 2 from the insertion state A to the withdrawal state B only when the second switch unit 2 is in the OFF state.

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

[0134] According to the present invention, 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 Internal (electrical or electronic) low-voltage components for feeding the switching device, such as controller 3, contact actuator 25, actuation arrangement 7, 8, and the aforementioned drive circuitry included in switching units 1, 2.

[0135] Generally speaking, external auxiliary power supply V AUX It can be derived from electrical line 50 via a suitable auxiliary power interface device (not shown), or it can be supplied by any external power source.

[0136] When available, such auxiliary power supply interface devices (generally not included in the switching device) can be of known types and will not be described here for the sake of brevity.

[0137] Preferably, the power supply stage 4 includes one or more drive circuits adapted to receive an external power supply voltage V. AUX And provides a charging current I for charging a suitable energy storage component (not shown). C .

[0138] According to the present invention, the switching device 100 includes an energy storage stage 9 electrically connected to the power supply stage 4 to receive a charging current I from the power supply stage 4. C .

[0139] Preferably, the energy storage stage 9 includes a rechargeable storage component (e.g., a capacitor bank or battery) for storing electrical energy and a suitable power supply voltage V to the low-voltage internal components of the switching device by drawing electrical energy from the aforementioned storage component. S A suitable interface circuit.

[0140] Preferably, the power supply stage 4 and the energy storage stage 9 are housed in a fixed section of the switching device.

[0141] According to some embodiments of the present invention, the power supply stage 4 and the energy storage stage 9 may be independent devices.

[0142] Preferably, the power supply stage 4 and the energy storage stage 9 can be integrated to form a single circuit structure.

[0143] Generally, the power supply stage 4 and energy storage stage 9 can be arranged at an industrial level based on known types of solutions. Therefore, for the sake of brevity, they will not be described in further structural or circuit details below.

[0144] According to an important aspect of the invention, the controller 3 is configured to control the first switching unit 1 and the second switching unit 2 such that both switching units are in an open state when the power supply stage 4 is subjected to a fault condition.

[0145] For clarity, it is specified that when power supply level 4 fails to operate normally, for example when power supply level 4 is unable to receive external auxiliary power supply V for any reason... AUX At that time, power supply level 4 experienced a "fault condition".

[0146] In practice, the fault condition of power supply level 4 corresponds to the switching device being unable to receive or utilize external auxiliary power supply to feed its low-voltage internal components.

[0147] Preferably, the controller 3 is configured to command both the first switching unit 1 and the second switching unit 2 to switch to or remain in the off state in response to receiving a sensing signal S2 indicating a fault condition of the power supply stage 4.

[0148] Preferably, the switching device 100 includes a power supply sensing component 6, which is adapted to provide a sensing signal S2 indicating the operating status of the power supply stage 4 to the controller 3. As an example, the sensing component 6 may include one or more voltage or current sensors (which may be of known types) adapted to signal a fault condition to the controller 3, such as when an external auxiliary power supply V... AUX Failure condition that makes it unavailable for any reason.

[0149] It has been confirmed that both switching units 1 and 2 can use the energy stored in the energy storage component 9 to perform disconnection operations commanded by the controller 3 in response to a fault condition of the power supply stage 4.

[0150] In this way, the switching device 100 can be kept in a safe state (where both switching units 1 and 2 are in the open state) before the low-voltage internal components of the switching device (in particular the controller 3, contact actuator 25 and the aforementioned drive circuit) are no longer fed.

[0151] Thanks to the solution provided by this invention, the switching device ensures a higher level of safety during operation. Even if the power supply stage 4 experiences a fault condition and the switching units 1 and 2 may be inoperable for a short period of time (in order to perform their opening operation), the withdrawal operation of the first switching unit 1 is prevented in the presence of leakage current.

[0152] According to another aspect of the invention, 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 and 2.

[0153] According to this control logic, when the first switching unit 1 and the second switching unit 2 are in insertion state A, they can only be combined to use specific operating configurations, each configuration corresponding to a predefined given operating state of the switching device 100. Figure 3 ).

[0154] Preferably, the controller 3 is configured to control the switching units 1 and 2 in a manner that allows them to operate in combination only according to the following operational configurations:

[0155] - First operating configuration [I], wherein both switching units 1 and 2 are in the closed state (ON); or

[0156] - Second operating configuration [X], wherein the first switch unit 1 is in the OFF state and the second switch unit 2 is in the ON state; or

[0157] -Third operation configuration [O], in which both switch units 1 and 2 are in the OFF state.

[0158] When switching units 1 and 2 are operated according to the first operating configuration [I], line current is allowed to flow through electrodes 1A and 2A of switching units 1 and 2. Therefore, there is electrical continuity between the first electrical conductor 51 and the second electrical conductor 52 of electrical circuit 50. Therefore, the first operating configuration [I] of switching units 1 and 2 corresponds to the closed state of switching device 100.

[0159] When switching units 1 and 2 are operated according to the second operating configuration [X], since the first switching unit 1 is in the OFF state, line current is not allowed to flow along the electrodes 1A and 2A of the switching units 1 and 2. The first line conductor 51 and the second line conductor 52 of the electrical circuit 50 are thus disconnected. However, since the second switching unit 2 is in the ON state and leakage current affecting the solid-state switch 10 can still flow along the electrodes 1A and 2A, there is no current insulation between the line conductors 51 and 52. The second operating configuration [X] of the switching units 1 and 2 corresponds to the standby state of the switching device 100, which is between the closed and open states.

[0160] When switching units 1 and 2 are operated according to the third operating configuration [O], since both switching units 1 are in the OFF state, line current and possible leakage current are not allowed to flow along the electrodes 1A and 2A of the switching units 1 and 2. The first line conductor 51 and the second line conductor 52 of the electrical circuit 50 are disconnected, and there is current insulation between the line conductors. Therefore, the third operating configuration [O] of the switching units 1 and 2 corresponds to the OFF state of the switching device 100.

[0161] Generally, the controller 3 is configured to command the switch units 1 and 2 to switch from one operating configuration to another in response to receiving the aforementioned input commands CM1, CM2, CM3 indicating the desired operating state of the switch unit 100.

[0162] However, according to the control logic implemented by controller 3, any transition between the operating configurations of switching units 1 and 2 must always involve the second operating configuration corresponding to the standby state of switching device 100 [X]( Figure 3 ).

[0163] In other words, the controller 3 is configured to control the switching units 1 and 2 in a manner that prevents any direct transition between the first operating configuration [I] and the third configuration [O] of the switching units 1 and 2.

[0164] Preferably, when the switching units 1 and 2 are in the first operating configuration [I] (corresponding to the closed state of the switching device 100), the controller 3 can command the switching units 1 and 2 to switch to the second operating configuration [X] (corresponding to the standby state of the switching device 100).

[0165] In practice, based on the control logic implemented by controller 3, switching units 1 and 2 can switch from the first operating configuration [I] to another operating configuration only through the second operating configuration [X].

[0166] When in the closed state (first operation configuration [I] of switch units 1 and 2), switch device 100 can switch to another operation state only through the standby state (second operation configuration [X] of switch units 1 and 2).

[0167] Preferably, when the switch units 1 and 2 are in the second operation configuration [X] (corresponding to the standby state of the switch unit 100), the controller 3 can command the switch units 1 and 2 to switch to the first operation configuration [I] (corresponding to the closed state of the switch device 100) or switch to the third operation configuration [O] (corresponding to the open state of the switch device 100).

[0168] In practice, based on the control logic implemented by controller 3, switching units 1 and 2 can switch from the second operation configuration [X] to the first operation configuration [I] or the third operation configuration [O].

[0169] When in standby mode (second operation configuration [X] of switch units 1 and 2), switch device 100 can either switch to closed mode (first operation configuration [I] of switch units 1 and 2) or switch to open mode (third operation configuration [O] of switch units 1 and 2).

[0170] Preferably, when the switching units 1 and 2 are in the third operation configuration [O] (corresponding to the off state of the switching device 100), the controller 3 can command the switching units 1 and 2 to switch to the second operation configuration [X] (corresponding to the standby state of the switching device 100).

[0171] In practice, based on the control logic implemented by controller 3, switching units 1 and 2 can switch from the third operation configuration [O] to another operation configuration only through the second operation configuration [X].

[0172] When in the off state (third operation configuration [O] of switch units 1 and 2), in response to receiving input commands CM1 and CM2 indicating different desired operation states, switch device 100 can switch to another operation state only through the standby state (second operation configuration [X] of switch units 1 and 2).

[0173] The control logic mentioned above is configured such that the withdrawal operation of the switch unit can only be performed when activated by the user, and each switch unit 1, 2 is in the OFF state.

[0174] Preferably, if the first switching unit 1 and the second switching unit 2 operate in combination according to the first operation configuration [I], then the controller 3 is configured to prevent the withdrawal operation of the first switching unit 1 (by disabling the first actuation arrangement 7 as mentioned above).

[0175] Preferably, the controller 3 is configured to prevent the first switch unit 1 from being pulled out if the second switch unit 2 is in the closed state (ON). In this case, the controller 3 is configured to prevent the first switch unit 1 from being pulled out if 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 first switch unit 1 from being pulled out only when the first switch unit 1 and the second switch unit 2 operate in combination according to the third operation configuration [O].

[0176] 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 OFF state. 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].

[0177] Conveniently, the control logic mentioned above is designed to take into account possible failure conditions of power supply level 4.

[0178] Preferably, the controller 3 is configured to control the first switching unit 1 and the second switching unit 2 such that when the power supply stage 4 is subjected to a fault condition, the first switching unit and the second switching unit are in the third operating configuration mentioned above [O].

[0179] Specifically, the controller 3 is configured to command the first switching unit 1 and the second switching unit 2 to switch to or remain in a third operating configuration [O] in response to receiving a sensing signal S2 indicating a fault condition of the power supply stage 4.

[0180] Preferably, when the first switching unit 1 and the second switching unit 2 operate in combination according to the first operating configuration [I] mentioned above, the controller 3, in response to receiving a sensing signal S2 indicating a fault condition of the power supply stage 4, commands the switching units to switch to the second operating configuration [X], and subsequently to the third operating configuration [O]. Figure 4 ).

[0181] When in the closed state (first operating configuration [I] of switch units 1 and 2), switch device 100 automatically switches to standby state (second operating configuration [X] of switch units 1 and 2), and then switches to open state in response to a fault condition of power supply stage 4 (third operating configuration [O] of switch units 1 and 2).

[0182] Preferably, when the first switching unit 1 and the second switching unit 2 operate in combination according to the second operating configuration [X] mentioned above, the controller 3, in response to receiving the sensing signal S2 indicating a fault condition of the power supply stage 4, commands the switching units 1 and 2 to switch to the third operating configuration [O]. Figure 5 ).

[0183] When in standby mode (second operation configuration [X] of switching units 1 and 2), the switching device 100 automatically switches to the off state in response to a fault condition of the power supply stage 4 (third operation configuration [O] of switching units 1 and 2).

[0184] Preferably, when the first switching unit 1 and the second switching unit 2 operate in combination according to the aforementioned third operating configuration [O], the controller 3, in response to receiving the sensing signal S2 indicating a fault condition of the power supply stage 4, commands the switching units 1 and 2 to remain in the third operating configuration [O]. Figure 6 ).

[0185] When in the open state (third operation configuration [O] of switching units 1 and 2), the switching device 100 cannot switch to a different state (e.g., standby state or closed state) due to the fault condition of power supply stage 4.

[0186] As is clear from the above, according to the control logic mentioned above, in response to a fault condition in the power supply stage 4, the switching device 100 is automatically put into a safe state (where both switching units 1 and 2 are in the open state). Moreover, in this case, both switching units 1 and 2 can use the energy stored in the energy storage component 9 to perform the disconnection operation commanded by the controller 3.

[0187] Compared to existing corresponding solutions, the switching device 100 of the present invention offers relevant advantages.

[0188] Unlike known solutions in the prior art, the controller 3 of the switchgear 100 is configured to perform emergency control actions in response to a failure condition of the power supply stage 4.

[0189] This emergency control action involves commanding SSCB switch unit 1 and electromechanical unit 2 to switch to or remain in the off state when the external auxiliary power supply becomes unavailable for any reason.

[0190] This solution prevents the first switching unit 1 from being pulled out in the presence of leakage current, even if the second switching unit 2 is in the closed state (ON), the leakage current may still circulate.

[0191] Therefore, even when the internal low-voltage components of the switching device can no longer be fed under normal conditions, the switching device 100 operates safely. In fact, the electrical energy stored in the energy storage stage 9 is mainly used to keep the switching device in a safe state (the open state of the two switching units 1 and 2).

[0192] According to an aspect of the invention, the controller 3 of the switching device is configured to control the switching units 1 and 2 such that, in addition to the closed state (first configuration [I] of the switching units 1 and 2) and the open state (third configuration [O] of the switching units 1 and 2), the switching device 100 can also take a standby state (second configuration [X] of the switching units).

[0193] This solution allows the time synchronization constraints between switching units 1 and 2 to be relaxed when the switching device 100 must perform an opening operation (i.e., a transition from a closed state to an open state) or a closing operation (i.e., a transition from an open state to a closed state).

[0194] Moreover, this control logic provides a safe state for the switching devices in response to a fault event in power supply stage 4 (third configuration [O] of switching units 1 and 2).

[0195] The switching device 100 can therefore operate according to robust control logic, which allows for improved overall efficiency and safety.

[0196] The switchgear 100 is relatively easy to manufacture at an industrial level and can be manufactured at a competitive cost compared to similar devices of the prior art.

Claims

1. A switching device (100) for a power distribution network, comprising: - One or more first line terminals and second line terminals (91, 92), which can be electrically connected to the corresponding first line conductor and second line conductor (51, 52) of the electrical circuit, respectively; A first switching unit (1) having one or more first electrodes (1A), each first electrode including a first electrode contact (11), a second electrode contact (12), and one or more solid-state switches (10), the first electrode contact (11) being electrically connected to a corresponding first line terminal (91), the one or more solid-state switches (10) being electrically connected to the first electrode contact and the second electrode contact and adapted to operate in an ON state or an OFF state to allow or interrupt current flow. The first switching unit (1) can reversibly switch between a closed state (ON) where the solid-state switch is in a conducting state and an open state (OFF) where the solid-state switch is in a blocking state. The first switching unit (1) is reversibly movable between an insertion state (A) in which the first pole contact is coupled to the first line terminal (91) and an extraction state (B) in which the first pole contact is decoupled from the first line terminal. A second switching unit (2) having one or more second electrodes (2A), each second electrode including a third electrode contact (23), a fourth electrode contact (24), and an electrical contact (20), the third electrode contact (23) being electrically connected to a corresponding second electrode contact (12) of a first switching unit (1), the fourth electrode contact (24) being electrically connected to a corresponding second line terminal (92), and the electrical contact (20) being electrically connected to the third electrode contact and the fourth electrode contact and adapted to operate in a coupled or decoupled state to allow or interrupt current flow. The second switching unit (2) can reversibly switch between a closed state (ON) where the electrical contact is in a coupled state and an open state (OFF) where the electrical contact is in a decoupled state. The second switching unit (2) is reversibly movable between an insertion state (A) in which the fourth pole contact is coupled to the second line terminal (92) and an extraction state (B) in which the fourth pole contact (24) is decoupled from the second line terminal; - Controller (3), the controller (3) being adapted to control the operation of the switching device; - Power supply stage (4), said power supply stage (4) is adapted to receive external power supply (V AUX ); The controller (3) is characterized in that it is configured to control the first switching unit and the second switching unit (1, 2) such that when the power supply stage (4) is subjected to a fault condition, both the first switching unit and the second switching unit are in an open state.

2. The switching device according to claim 1, characterized in that, The controller (3) is configured to command the first switching unit (1) and the second switching unit (2) to switch to or remain in the off state in response to receiving a sensing signal (S2) indicating a fault condition of the power supply stage (4).

3. The switching device according to one or more of the preceding claims, characterized in that, The switching device includes a power supply sensing component (6) adapted to provide the controller (3) with a sensing signal (S2) indicating the operating status of the power supply stage (4).

4. The switching device according to one or more of the preceding claims, 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 in combination according to the following operation configuration: - A first operating configuration ([I]) corresponding to the closed state of the switching device, wherein both the first switching unit and the second switching unit (1, 2) are in the closed state (ON); or - A second operation configuration ([X]) corresponding to the standby state of the switching device, wherein the first switching unit (1) is in the off state (OFF) and the second switching unit (2) is in the closed state (ON); or - A third operation configuration ([O]) corresponding to the off state of the switching device, wherein the first switching unit and the second switching unit (1, 2) are both in the off state (OFF); The controller (3) is configured to control the first switching unit and the second switching unit (1, 2) such that when the power supply stage (4) is subjected to a fault condition, the first switching unit and the second switching unit are in the third operating configuration ([O]).

5. The switching device according to claim 4, characterized in that, The controller (3) is configured to command the first switching unit (1) and the second switching unit (2) to switch to or remain in the third operating configuration ([O]) in response to receiving a sensing signal (S2) indicating a fault condition of the power supply stage (4).

6. The switching device according to claim 5, characterized in that, When the first switching unit and the second switching unit (1, 2) operate in combination according to the first operating configuration ([I]), the controller (3) commands the first switching unit and the second switching unit (1, 2) to switch to the second operating configuration ([X]) and then switch to the third operating configuration ([O]) in response to receiving a sensing signal (S2) indicating a fault condition of the power supply stage (4).

7. The switching device according to any one of claims 5 to 6, characterized in that, When the first switching unit and the second switching unit (1, 2) operate in combination according to the second operating configuration ([X]), the controller (3) commands the first switching unit and the second switching unit (1, 2) to switch to the third operating configuration ([O]) in response to receiving a sensing signal (S2) indicating a fault condition of the power supply stage (4).

8. The switching device according to any one of claims 5 to 7, characterized in that, When the first switching unit and the second switching unit (1, 2) operate in combination according to the third operating configuration ([O]), the controller (3) commands the first switching unit and the second switching unit (1, 2) to remain in the third operating configuration ([O]) in response to receiving a sensing signal (S2) indicating a fault condition of the power supply stage (4).

9. The switching device according to one or more of the preceding claims, characterized in that, The switching device includes a first actuation arrangement (7) adapted to actuate the first switching unit (1) at least during the withdrawal operation of the first switching unit when activated by a user.

10. The switching device according to one or more of the preceding claims, characterized in that, The switching device includes a second actuation arrangement (8) adapted to actuate the second switching unit (2) at least during the withdrawal operation of the second switching unit when activated by a user.

11. The switching device according to one or more of the preceding claims, 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 the desired operating state of the switching device.

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

13. The switching device according to claim 11 or 12, characterized in that, The interface section (33) is able to receive the input commands (CM1, CM2, CM3) from the remote computerized device (9).

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

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