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EP-4010914-B1 - ELECTRICAL SWITCH FOR OPENING A CURRENT PATH

EP4010914B1EP 4010914 B1EP4010914 B1EP 4010914B1EP-4010914-B1

Inventors

  • OEHLER, FABIAN
  • WORTBERG, MICHAEL

Dates

Publication Date
20260513
Application Date
20190805

Claims (8)

  1. Electrical switch (100) for breaking a current path (102), wherein the switch (100) has a feed line (108) with a breaking point (112) for breaking the current path (102), wherein a switching element (114) which is movable at least on one side is arranged at the breaking point (112) in the feed line (108) for opening and/or closing the breaking point (112), wherein the switching element (114) has a contact point (118) to the feed line (108) on a movable side in a closed position, wherein the switch (100) further has a return line (110) which is electrically conductively connected to the feed line (108) at one end of the feed line (108), wherein an arrangement of the feed line (108) and the return line (110) in a manner spaced apart substantially antiparallel, at least in the region of the breaking point (112), is designed for at least partially compensating for a force which, while the current path (102) is carrying current, acts on the switching element (114) due to a local Lorentz force in the feed line (108) and the switching element (114) and a constriction force (122) at the contact point (118) by means of a Lorentz force (124) which acts on the switching element (114) from the return line (110), having an extinguishing device (300) for extinguishing a switching arc (400) resulting from breaking the current-carrying breaking point (112), characterized in that the extinguishing device (300) has a fuse element (304), which is de-energized during regular operation, in a secondary path (302) to the current path (102), wherein the fuse element (304) is connected between a connection to a first side of the breaking point (112) and a secondary electrode (306) of the secondary path (302), wherein the secondary electrode (306) is arranged in the region of a second side of the breaking point (112) and is electrically insulated from the current path (102) during regular operation, further comprising an arc chute (310) which is arranged adjacent to the breaking point (112) and has at least two prongs, wherein the prongs (308) are oriented substantially parallel to each other, are electrically isolated from each other and are arranged distributed over an opening width of the breaking point (112), wherein the secondary electrode (306) is connected to at least one of the prongs (308), further comprising at least one blowout coil (126) which is arranged adjacent to the breaking point (112) and is designed to deflect the switching arc (400) from the breaking point (112), wherein the blowout coil (126) is configured to drive the switching arc (400) into the arc chute (310).
  2. Switch (100) according to Claim 1, wherein a length (L) of the switching element (114) in the direction of extent of the switching element (114) and a distance (d) between the switching element (114) and the return line (110) in a direction perpendicular to the direction of extent of the switching element (114) are dimensioned in such a way that the force which acts on the switching element (114) at the contact point (118) due to the local Lorentz force and the constriction force (122) is compensated for by at least 50% by means of the Lorentz force (124) that is created in the return line (110) while the current path (102) is carrying current at a current (I) which flows through the current-carrying current path (102) and for which the switch (100) is designed.
  3. Switch (100) according to either of the preceding claims, wherein the switching element (114) detachably bears against the feed line (108) at the contact point (118) on a side directed towards the return line (110).
  4. Switch (100) according to any of the preceding claims, in which the switching element (114) can be moved into an intermediate space (120) between the feed line (108) and the return line (110) for opening the breaking point (112).
  5. Switch (100) according to any of the preceding claims, further comprising an actuator (116) for bringing the switching element (114) to and moving the switching element (114) away from the contact point (118).
  6. Switch (100) according to any of the preceding claims, in which the switching element (114) is designed as a switching bridge which is movable on both sides, wherein the switching bridge is oriented substantially parallel to the return line (110).
  7. Switch (100) according to any of the preceding claims, in which the prongs (308) of the arc chute (310) are designed as plates which are oriented substantially parallel to each other, wherein a leading edge of the plates is arranged spaced apart from the current path (102) in the region of the breaking point (112) and is oriented substantially parallel to the current path (102).
  8. Switch (100) according to any of the preceding claims, further comprising a movable, electrically insulating element (200) which can be pushed into the opened breaking point (112) and an actuator (204) for moving the element (200).

Description

Technical field The present invention relates to an electrical switch for disconnecting a current path, in particular in high-voltage current paths in a motor vehicle electrical system. State of the art The present invention is described below primarily in connection with switching elements for vehicle electrical systems. However, the invention can be used in any application where electrical loads are switched. For example, if a high current flows through a switch in a vehicle electrical system in the event of a short circuit in a drive system, a contact point may be unintentionally opened by a Lorentz force and/or clamping force in the contact point caused by the current flow. When the contact point opens during a high current flow, a switching arc forms at the separation point between the two previously connected ends of the switch. This switching arc releases a large amount of energy, which can damage the switch. To prevent such damage, it is best to avoid unintentionally opening a switch operated with high current. Additionally, efforts should be made to reduce the duration of the switching arc, for example, by making the voltage drop in the switching arc greater than the available electrical voltage between its ends. The voltage drop can For example, the arc length can be increased by lengthening the switching arc. This can be achieved, for instance, by using an airflow or gas flow that deflects the switching arc. This lengthens the switching arc and increases the voltage drop in the switching arc to such an extent that the switching arc extinguishes. The printed matter EP 2 680 288 A1 This concerns a contactor arrangement for operation in a dielectric liquid environment and an electrical underwater device. The printed matter EP 2 122 645 A1 This concerns a plate-shaped extinguishing element for an extinguishing device of a switching device. The printed matter US 2013/021121 A1 shows a relay for opening and closing an electrical circuit. The printed matter DE 10 2017 205833 A1 This concerns a contactor device for a motor vehicle. The printed matter US 2013/021122 A1 This concerns a relay that can restrict separation between moving contacts and fixed contacts due to an electromagnetic repulsion force of a contact section. The printed matter US 4 467 301 A refers to electrical switches and to electrical switches of the type that uses a bridging contact which can be moved linearly in and out of engagement with a pair of fixed contacts. The printed matter WO 2019/103064 A1 describes a contact device, an electromagnetic relay and an electrical device that are able to stabilize a connection state between a movable contact and a fixed contact in a case where an abnormal current flows. The printed matter WO 2019/031587 A1 relates to an electromagnetic relay comprising: a housing; a first fixed contact terminal with a first fixed contact; a second fixed contact terminal with a second fixed contact; and a movable contact element comprising a first movable contact and a second movable contact element on a surface. has contacts that can contact and disconnect in the contact and separation direction of a contact. Description of the invention One object of the invention is to provide a reliably switching electrical switch for disconnecting a current path using the simplest possible means in terms of construction. The problem is solved by the subject matter of the independent claim. Advantageous embodiments of the invention are specified in the dependent claims, the description, and the accompanying figures. An electrical switch for disconnecting a current path is presented, wherein the switch has a lead-in conductor with a disconnect point for disconnecting the current path, wherein at the disconnect point a switching element movable on at least one side for opening and/or closing the disconnect point is arranged in the lead-in conductor. wherein the switching element in a closed position has a contact point to the supply line on a movable side, wherein the switch further comprises a return conductor which is electrically conductively connected to the forward conductor at one end of the forward conductor, wherein an essentially antiparallel spaced arrangement of forward and return conductors is designed, at least in the area of the separation point, to at least partially compensate a force acting on the switching element due to a local Lorentz force in the forward conductor and the switching element and/or a constriction force in the contact point when the current-carrying current path is active, by means of a Lorentz force acting on the switching element from the return conductor. A current path can be understood as a continuous electrically conductive path between a power source and a load. The power source could be, for example, the traction battery of an electric vehicle. The load could be, for example, the electric vehicle's drive motor. A switch can open, interrupt, or disconnect the current path. The switch