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EP-4579711-B1 - ELECTRICAL CUT-OFF SYSTEM

EP4579711B1EP 4579711 B1EP4579711 B1EP 4579711B1EP-4579711-B1

Inventors

  • ANDONISSAMY, Arokiaraj
  • DUBOC, Sébastien, Roger, Pierre
  • LEMMEL, Guillaume
  • OEUVRARD, Jean-François

Dates

Publication Date
20260513
Application Date
20220224

Claims (8)

  1. An electrical system (2) for interrupting an electrical current, including a circuit breaker (4), a fuse (12) and an electrical device (10, 10b), the electrical device (10b) including a body (30) delimiting a closed internal volume, a first electrode (E1), a second electrode (E2) and a third electrode (E3), a free end of each electrode opening into the internal volume, said free ends of each electrode being arranged inside the internal volume, at a distance from each other and opposite with respect to the other electrodes, wherein the first electrode (E1), the second electrode (E2) and the third electrode (E3) are spaced apart and separated by a volume of gas, such as air, the breakdown voltage between the second electrode (E2) and the first electrode (E1) being lower than the breakdown voltage between the second electrode (E2) and the third electrode (E3), wherein within the volume, the free end of the third electrode (E3) is separated by a fuse wall (62) from the free ends of the first electrode (E1) and of the second electrode (E2), the electrical device being configured for: - prohibiting the flow of current between the first electrode and the third electrode when the electric current or the electric voltage between the first electrode (E1) and the second electrode (E2) stays below a predefined threshold value; - letting the current flow between the first electrode and the third electrode when said electric current or said electric voltage exceeds said threshold value, wherein: - the electrical device being connected in series with the fuse (12), the fuse and the electrical device being connected together in parallel with the circuit breaker (4) by means of the first electrode (E1) and of the third electrode (E3), the second electrode (E2) opening into a breaking chamber of the circuit breaker (4), - current flow is made through an electric arc (A), initially established between the first electrode (E1) and the second electrode (E2), said arc (A) being then diverted to be established between the first electrode (E1) and the third electrode (E3).
  2. The electrical system (2) according to claim 1, wherein the second electrode (E2) is connected to an internal electrical conductor (28) of the circuit breaker (4) before or after actuating the circuit breaker, the internal conductor being coupled to at least one of the terminals (6, 8) of the circuit breaker (4).
  3. The electrical system (2) according to claim 2, wherein the second electrode (E2) is connected to the internal electrical conductor (28) through an insulating member such as a voltage suppressor element (60) or a varistor.
  4. The electrical system (2) according to claim 1, wherein the system includes an additional circuit breaker connected in series with said circuit breaker (4) by the respective terminals (6, 8) thereof, the second electrode (E2, 29) being connected at the junction between said circuit breakers.
  5. The electrical system according to claim 1, wherein the second electrode (E2, 29) is arranged in the breaking chamber opposite to and at a distance from one of the terminals (6, 8) of the circuit breaker (4).
  6. The electrical system (2) according to any one of claims 1 to 4, wherein the fuse (12) and the electrical device (10;10b) are integrated within the same body (70).
  7. The electrical system (2) according to any one of claims 1 to 4, wherein the circuit breaker (4) and the electrical device (10; 10b) are integrated within the same body.
  8. The electrical system (2) according to any one of claims 1 to 6, wherein the circuit breaker (4) is a pyrotechnic circuit breaker.

Description

The invention relates to an electrical device and an electrical system for interrupting an electric current. The invention is particularly applicable to the field of electrical protection. For a long time, fuses have been used to effectively protect electrical equipment and installations against electrical faults. Fuses typically consist of a fusible blade housed in a casing filled with a material such as silica. The blade is designed to melt when the current flowing through the fuse exceeds a predetermined value for a specified duration. Some modern applications now require the ability to interrupt high-intensity electrical currents with a very fast response time. This is the case, for example, with applications related to electric vehicles or photovoltaic panels. In this regard, it has been proposed to combine a pyrotechnic circuit breaker with a conventional fuse, in order to increase breaking performance. WO 2018/167169 A1 describes an example of such an electrical device, in which a fuse is connected in parallel with a pyrotechnic circuit breaker. In this example, the pyrotechnic circuit breaker is configured to trip with a very short reaction time in the event of an electrical fault, and the fuse is configured to ensure total interruption of the current, for example to prevent any reformation of an electrical arc in the pyrotechnic circuit breaker. In other words, the fuse helps to interrupt an electrical current that the circuit breaker alone could not have stopped safely and effectively. However, the fuse should only be connected in parallel with the circuit breaker when the circuit breaker is triggered, to prevent the fuse from being constantly traversed by an electric current, as this could lead to premature aging of the fuse. Furthermore, some known devices do not allow the circuit to be opened when the currents have a low intensity or even (temporarily) zero, which may nevertheless be required for certain applications. To achieve this, it is generally necessary to modify the internal architecture of the pyrotechnic circuit breaker, similar to what is proposed by WO-2020/260382 A1 (Or FR-3 098 006-A1 ), which can, however, be complicated to achieve industrially. Therefore, there is a need for an electrical disconnect device that addresses the above drawbacks. In general, the invention relates to an electrical system according to claim 1. According to advantageous but not mandatory aspects, such an electrical system may incorporate one or more of the features defined in the dependent claims, the features being taken in isolation or in any technically permissible combination. The invention will be better understood and other advantages thereof will become more apparent in the light of the following description of an embodiment of a device for interrupting an electric current, given solely by way of example and with reference to the accompanying drawings, in which: [ Fig 1 ] there figure 1 schematically represents a device for interrupting an electric current comprising an electrical cutting element, but not part of the invention; [ Fig 2 ] there figure 2 schematically represents two alternative switching elements to the electrical switching element of the device. figure 1 : [ Fig 3 ] there figure 3 schematically represents a first state of operation of the device. figure 1 ; [ Fig 4 ] there figure 4 schematically represents a second operating state of the device. figure 1 ; [ Fig 5 ] there figure 5 schematically represents a third operating state of the device. figure 1 ; [ Fig 6 ] there figure 6 schematically represents another embodiment of the device of the figure 1 according to the invention [ Fig 7 ] there figure 7 schematically represents two examples of the construction of an electrical switching element, respectively for the switching device of the Figures 1 And 6 (insert a) and for the shut-off device of the figure 8 (insert b), not forming part of the invention; [ Fig 8 ] there figure 8 schematically represents another possible implementation of the device. figure 1 , not being part of the invention. There figure 1 represents an electrical system 2 configured to interrupt an electric current, for example to protect an electrical load or an electrical installation. Device 2 includes a circuit breaker 4 having terminals 6 and 8, allowing the circuit breaker 4 to be connected to an electrical circuit, for example between an electrical load and a generator. Device 2 also includes an electrical device 10 and a fuse 12 electrically connected in parallel with the circuit breaker 4 between terminals 6 and 8. For example, fuse 12 is a fuse cartridge containing one or more fuse blades F2. In general, the circuit breaker 4 can be switched from an electrically conductive state to an electrically blocking (or open) state. The circuit breaker 4 may be a pyrotechnic circuit breaker. For example, the circuit breaker 4 may contain an explosive charge configured to, when triggered, physically sever an elec