Electrical switching unit having a safety device

Abstract

Electrical switching unit (1) for a high-voltage drive system of a hybrid or electric vehicle, comprising a contact apparatus having at least one stationary first connection element (2) and at least one movable second connection element (4), wherein the movable second connection element (4) can be actuated via a first actuator (6) into a closed position, in which the first connection element (2) and the second connection element (4) are electrically connected, and into an open position, in which the first connection element (2) and the second connection element (4) are not electrically connected, and comprising a safety device having at least one electrically insulating disconnection element (7) and at least one second actuator (8), wherein the disconnection element (7) is designed so that it can be displaced via the second actuator (8) in such a way that, when required, it can be moved into the region between the first connection element (2) and the second connection element (3) irrespective of the position of the movable contact bridge (5).

Description

[0001] Electrical switching unit with safety device

[0002] Field of the invention

[0003] The present invention relates to an electrical switching unit for a high-voltage drive system of a hybrid or electric vehicle, comprising a contact device with at least one fixed first connection element and at least one movable second connection element, wherein the movable second connection element can be actuated via a first actuator into a closed position in which the first connection element and the second connection element are electrically connected, and into an open position in which the first connection element and the second connection element are not electrically connected, and comprising a safety device.

[0004] State of the art

[0005] High-voltage architectures of hybrid and electric vehicle energy storage systems often use fuses and / or pyrotechnic fuses to protect against electrical short circuits and / or overloads. In both cases, separate components must be integrated into the high-voltage path.

[0006] The use of fuses not only requires additional installation space and additional interfaces, but also leads to undesirable aging. Even under normal load, fuses are damaged and can therefore lead to undesirable triggering behavior over their service life. Unlike thermal fuses, pyrotechnic fuses do not exhibit aging. Nevertheless, the use of this type of fuse, similar to the fuse, requires additional installation space and additional interfaces. Furthermore, the force of the pyrotechnic fuse must be sufficiently high to be able to break a copper or aluminum busbar designed for currents of up to 600 amperes.

[0007] Summary of the invention

[0008] It is an object of the invention to provide an improved electrical switching unit for a high-voltage drive system of a hybrid or electric vehicle, which is characterized in particular by a reduced installation space requirement.

[0009] This need can be met by the subject matter of the present invention according to independent claim 1. Advantageous embodiments of the present invention are described in the dependent claims.

[0010] An electrical switching unit according to the invention for a high-voltage drive system of a hybrid or electric vehicle comprises a contact device and a safety device.

[0011] According to the invention, the contact device has at least one fixed first connection element and at least one movable second connection element.

[0012] According to the present invention, the movable second connection element can be actuated via a first actuator into a closed position in which the first connection element and the second connection element are electrically connected, and into an open position in which the first connection element and the second connection element are not electrically connected.

[0013] According to the invention, the safety device has at least one electrically insulating separating element and at least one second actuator, wherein the separating element is designed to be displaceable via the second actuator in such a way that it can be moved into the area between the first connecting element and the second connecting element if necessary, usually in the event of an electrical fault when the movable second connecting element is in the closed position.

[0014] In a particularly preferred embodiment of the present invention, the separating element is wedge-shaped, tapering toward a connecting element. However, the separating element can also be configured in any other desired shape.

[0015] The second actuator can be designed as a pyromechanical actuator, via which the isolating element can be moved from a basic position into a isolating position, namely a position between the first connection element and the second connection element, by means of an explosive movement. In contrast to conventional pyrotechnic fuses, an isolating element is not used to break a busbar, but rather to prevent contact between the movable second connection element and the stationary, i.e. fixed, first connection element. The force required for this is less than the force required to sever a solid busbar. By using a pyromechanical actuator, the necessary shutdown speeds can be achieved, for example in the event of a low-resistance short circuit.However, any other actuator capable of providing the necessary triggering times is also conceivable. A pyromechanical actuator is generally an irreversibly triggered actuation mechanism—once the propellant charge is used up, it must be replaced.

[0016] However, the separating element can also be designed to be reversibly actuated. The resulting solution can be used, for example, to guide an arc generated during a closing and / or opening sequence, as well as for automatic or manual locking during servicing. Such a reversible separating function can also be used in the event of a possible return spring break (of the movable connecting element) to implement safe emergency operation.

[0017] Brief description of the drawings

[0018] The invention is described below by way of example with reference to the drawings.

[0019] Fig. 1 shows a side view of an electrical switching unit with a movable second connection element in the closed position and a separating element in the basic position.

[0020] Fig. 2 shows a side view of an electrical switching unit with a movable second connection element in the open position and a separating element in the separating position

[0021] Fig. 3 shows a cross section through an electrical switching unit according to Fig. 1 . Detailed description of the invention

[0022] An exemplary embodiment of an electrical switching unit 1 according to the invention for a high-voltage drive system of a hybrid or electric vehicle is described in more detail below with reference to FIGS. 1, 2 and 3.

[0023] The electrical switching unit 1 comprises a housing 10, a contact device, and a safety device. The contact device and the safety device are essentially arranged in the housing 10.

[0024] The contact device has two fixed first connection elements 2 and two movable second connection elements 4.

[0025] The two second connection elements 4 are arranged on a movable contact bridge 5. In the present embodiment, the two first connection elements 2 are each designed as a fixed busbar.

[0026] The movable contact bridge 5 and thus the two second connecting elements 4 can be actuated by a first actuator 6 against the spring force of elastic elements 9 into a closed position (Fig. 1, Fig. 3), in which the first connecting element 2 and the second connecting element 4 are electrically connected, and into an open position (Fig. 2), in which the first connecting element 2 and the second connecting element 4 are not electrically connected. The movable contact bridge 5 can be guided via guide pins 11 fixed in the housing 10.

[0027] The safety device comprises an electrically insulating isolating element 7 and a second actuator 8. The isolating element 7 can be moved by the second actuator 8 from a home position into a disconnected position, and vice versa when using a reversibly triggerable second actuator 8, regardless of the position of the movable contact bridge 5, into a region between the first connection element and the second connection element. Such a displacement of the isolating element 7 is triggered in particular in the event of an electrical fault, such as an electrical short circuit or an electrical overload, and causes an interruption of the current flow via the first connection element 2 and the second connection element 4 (Fig. 2).

[0028] The separating element 7 is wedge-shaped—its two side surfaces converge at an acute angle. This acute angle forms in the direction of the connecting elements 2, 4.

[0029] In the present embodiment, the second actuator 8 is designed as a pyromechanical actuator, via which the separating element 7 can be transferred by an explosive movement starting from a basic position into a separating position, namely a position between the first connecting element and the second connecting element.

[0030] A stop plate 12 is provided to stop the explosive movement of the separating element 7. This is arranged on the movable contact bridge 5 and prevents further (unintentional) displacement of the separating element 7. List of reference symbols

[0031] Electrical switching unit

[0032] First connecting element

[0033] Second connection element

[0034] Movable contact bridge

[0035] First actuator

[0036] Separating element

[0037] Second actuator

[0038] Elastic element

[0039] Housing

[0040] guide pin

[0041] stop plate

Claims

Patent claims 1. Electrical switching unit (1) for a high-voltage drive system of a hybrid or electric vehicle, comprising a contact device with at least one fixed first connection element (2) and at least one movable second connection element (4), wherein the movable second connection element (4) can be actuated via a first actuator (6) into a closed position in which the first connection element (2) and the second connection element (4) are electrically connected, and into an open position in which the first connection element (2) and the second connection element (4) are not electrically connected, and comprising a safety device with at least one electrically insulating separating element (7) and at least one second actuator (8), wherein the separating element (7) is designed to be displaceable via the second actuator (8) in such a way that, when required, it can be moved independently of the position of the movable contact bridge (5),can be moved into the area between the first connecting element (2) and the second connecting element (3)., 2. Electrical switching unit (1) according to claim 1, characterized in that the separating element (7) is wedge-shaped, tapering in the direction of a pair of connecting elements (2, 4).

3. Electrical switching unit (1) according to claim 1 or 2, characterized in that the second actuator (8) is designed as a pyromechanical actuator via which the separating element (7) can be transferred from a basic position into a separating position by an explosive movement.

4. Electrical switching unit (1) according to claim 1 or 2, characterized in that the separating element (7) is designed to be reversibly actuated.

Images