High-voltage component with insulation fault generation device

Abstract

The invention relates to a high-voltage component (1) for a high-voltage electrical system of a motor vehicle, comprising: - an electronic circuit (2), - a housing (4) in which the electronic circuit (2) is arranged, - high-voltage connections (6a, 6b) connected to the electronic circuit (2) for connection to a device external to the high-voltage component, and, - at least one passive insulation fault generation device (10) arranged in the housing (4) for deliberately generating an insulation fault between one of the high-voltage terminals (6a) and a further terminal (A) in the event of an accident-related force (8) acting on the high-voltage component (1), comprising a first contact element (12) which is electrically connected to the high-voltage terminal (6a), a second contact element (13) which is electrically connected or connectable to the further terminal (A) and which is arranged at least in part in a force-absorbing region (7) of the housing (4), and an insulation barrier (14) arranged between the first contact element (12) and the second contact element (13), wherein the second contact element (13) is designed to absorb the accident-related force (8) acting on the force-absorbing region (7),to bridge the insulation barrier (14) and to contact the at least one first contact element (12) at least temporarily to generate the insulation fault.,

Description

[0001] The invention relates to a high-voltage component for a high-voltage electrical system of a motor vehicle, comprising an electronic circuit, a housing in which the electronic circuit is arranged, and high-voltage terminals connected to the electronic circuit for connection to a device external to the high-voltage component. The invention also relates to a high-voltage electrical system and a motor vehicle.

[0002] In this case, the focus is on high-voltage electrical systems for electrified motor vehicles, such as electric vehicles (BEVs), hybrid vehicles (PHEVs), or fuel cell vehicles (FCEVs). Such high-voltage electrical systems typically comprise multiple high-voltage components, which may be configured, for example, as a power electronics module, such as an inverter, or a charger. In the event of a motor vehicle crash, despite damage to a high-voltage component, an undesired energy flow may continue via an existing electrical connection between the high-voltage component and a device external to the high-voltage component. This energy flow may damage the device external to the high-voltage component or result in the presence of a dangerous voltage at the device external to the high-voltage component.

[0003] DE 10 2021 116 831 A1 discloses a shutdown device for a high-voltage electrical system of a motor vehicle, which device comprises at least one intermediate circuit section of an intermediate circuit of the high-voltage electrical system and a discharge unit designed to shut down the high-voltage electrical system in the event of an accident-related force acting on the motor vehicle, discharging the intermediate circuit by causing an active short circuit. The discharge unit can be mechanically activated by the accident-related force and, for this purpose, has at least one electrically conductive short-circuiting element, which can be moved between two electrical conductors of the intermediate circuit section by the accident-related force in order to electrically connect the two electrical conductors to short-circuit the intermediate circuit.

[0004] DE 10 2018 204 382 A1 shows an intermediate circuit capacitor for an electric motor-driven vehicle, which has a receptacle for a discharge module of a high-voltage component of the vehicle in its interior.

[0005] DE 10 2012 001 150 B4 discloses a device comprising a battery for driving a hybrid or electric vehicle, an electric motor for driving at least one wheel of the hybrid or electric vehicle, and a power cable electrically connecting the battery and the electric motor. The power cable has a grounding conductor separated from the electrical conductor by a first electrically insulating layer and a second electrically insulating layer on the grounding conductor. At least in one section of the power cable, the first electrically insulating layer and / or the grounding conductor are configured such that contact can be established between the electrical conductor and the grounding conductor by applying sufficiently high pressure to the surface of the power cable.

[0006] It is an object of the present invention to provide a simple, cost-effective and reliable solution for transferring a high-voltage component of a high-voltage electrical system of a motor vehicle into a safe state.

[0007] This object is achieved according to the invention by a high-voltage component, a high-voltage electrical system, and a motor vehicle having the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims, the description, and the figures.

[0008] A high-voltage component according to the invention for a high-voltage electrical system of a motor vehicle comprises an electronic circuit, a housing in which the electronic circuit is arranged, and high-voltage terminals for connecting to a device external to the high-voltage component, which are connected to the electronic circuit. Furthermore, the high-voltage component comprises at least one passive insulation fault generation device arranged in the housing for deliberately generating an insulation fault between one of the high-voltage terminals and another terminal in the event of an accident-related force acting on the high-voltage component.The insulation fault generation device comprises a first contact element, which is electrically connected to the high-voltage connection, a second contact element, which is electrically connected or connectable to the further connection and which is arranged in a force-absorbing region of the housing, and an insulation barrier arranged between the first contact element and the second contact element. The second contact element is designed to absorb the accident-related force acting on the force-absorbing region, to bridge the insulation barrier, and to at least temporarily contact the at least one first contact element to generate the insulation fault.

[0009] The invention further relates to a high-voltage electrical system for a motor vehicle having at least one high-voltage component according to the invention. Furthermore, the high-voltage electrical system can have a monitoring device designed to detect an insulation fault deliberately generated by the insulation fault generation device and to initiate a protective measure. A motor vehicle according to the invention comprises a high-voltage electrical system according to the invention. The motor vehicle is designed, in particular, as an electrified motor vehicle. The at least one high-voltage component is arranged, in particular, in a deformation zone or crumple zone of the motor vehicle. As a result, in the event of a crash or collision of the motor vehicle, the high-voltage component is at least partially exposed to an accident-related force, which can deform at least the force-absorbing area of ​​the housing of the high-voltage component.

[0010] The electronic circuit of the high-voltage component has at least one electronic component. The high-voltage connections can, for example, have high-voltage connectors arranged in a housing wall of the housing and electrically connected to the electronic circuit within the housing. The high-voltage connections can, for example, be connected to the device external to the high-voltage component via high-voltage cables. The device external to the high-voltage component is a device different from the high-voltage component with which the high-voltage component can exchange electrical energy. The high-voltage connections and the electronic circuit are arranged, in particular, away from or outside the force-absorbing area of ​​the housing.The force absorption area is an area of ​​the housing that includes a section of the housing wall and a portion of the housing interior, and through which the accident-related impact energy is absorbed. This force absorption area is designed to be deformable as a result of the accident-related force.

[0011] To prevent further energy exchange between the high-voltage component and the device external to the high-voltage component in the event of an accident-related impact on the motor vehicle, a defined fault is deliberately generated, temporarily or permanently, and a safety measure is subsequently initiated. For example, the safety measure can include shutting down the high-voltage electrical system, i.e., disconnecting a high-voltage energy storage device from the remaining high-voltage components, and / or shutting down a low-voltage electrical system of the motor vehicle. The defined fault is an insulation fault, which can be detected, for example, by the monitoring device already present in the motor vehicle, which then initiates the appropriate safety measure, or which can directly lead to a safe state of the high-voltage component.In the event of an accident, the insulation fault is generated by the passive insulation fault generation device. The insulation fault generation device requires no control but is triggered directly by the force applied during the accident.

[0012] The insulation fault generating device at least comprises a pair of contact elements, each comprising a first and a second contact element. During normal operation of the high-voltage vehicle electrical system, apart from a crash situation, only the first contact element is electrically connected to the associated high-voltage terminal. The first contact element can be arranged in the housing interior within or outside the force-absorbing area of ​​the housing. The second contact element is arranged in the housing interior within the force-absorbing area of ​​the housing at a distance from the first contact element and is electrically insulated from the first contact element by means of the insulation barrier. The second contact element is or can be electrically connected to the further terminal.The design of the further connection to which the second contact element is or can be electrically connected determines the type of insulation fault generated by the insulation fault generating device.

[0013] In the event of a crash, the second, or for example only the second, contact element is deformed, for example bent, in such a way that it bridges the insulation barrier and contacts the first contact element. This creates a conductive electrical connection between the associated high-voltage connection and the further connection, through which a fault current flows. The insulation barrier can be air, for example. However, the insulation barrier is preferably a physical insulation layer, for example a mica layer. This insulation layer is normally intact. In the event of a crash, it can be destroyed, for example crushed, punctured, or broken, by the at least one second contact element in order to bridge the gap.

[0014] Using the passive insulation fault generation device, a defined fault can be generated in a simple and cost-effective manner, which can then trigger a defined safety measure. This advantageously ensures that the vehicle is in a defined, contact-safe state after a crash.

[0015] In a first variant, the further connection to which the second contact element is electrically connected is designed as a ground connection of the high-voltage component. The at least one insulation fault generation device is thus configured to generate a short circuit between the high-voltage connection and the ground connection as the insulation fault. The ground connection of the high-voltage component can be formed, for example, by the housing of the high-voltage component. The ground connection can be electrically connected to a ground potential of the high-voltage on-board electrical system, for example a body of the motor vehicle. In this variant, the high-voltage component can also have two insulation fault generation devices, each high-voltage connection being connected to a respective first contact element.In the event of a crash, the fault current flowing through the conductive connection between at least one high-voltage connection and ground potential can be detected, for example, by a monitoring device in the form of an insulation monitor of the high-voltage vehicle electrical system, which then initiates the safety measure. The fault current can also flow through a monitoring device in the form of an overcurrent protection switch, which then triggers and de-energizes the high-voltage component.

[0016] In a second variant, the further connection to which the second contact element is electrically connected is designed as the other high-voltage connection. The at least one insulation fault generation device is thus designed to generate a short circuit between the high-voltage connections of the high-voltage component as the insulation fault. In this variant, the high-voltage component has only one insulation fault generation device, wherein the first contact element is electrically connected to one high-voltage connection and the second contact element is electrically connected to the other high-voltage connection. In the event of a crash, a conductive electrical connection is established between the high-voltage connections, via which a fault current flows in the form of a short-circuit current.

[0017] In a third variant, the further connection to which the second contact element is electrically connectable is designed as a ground connection. The at least one insulation fault generation device is configured to generate a ground fault between the high-voltage connection and the ground connection as the insulation fault. In this variant, the high-voltage component can in turn have an insulation fault generation device for each high-voltage connection. In the event of a crash, the insulation fault generation device creates a conductive connection between at least one of the high-voltage connections and the ground connection, which is connected to a grounded part, through which conductive connection the fault current can flow away. The flow of the fault current simultaneously corresponds to the safety measure.

[0018] The high-voltage component is preferably a charger or OBC (on-board charger) of the motor vehicle, whose electronic circuit is designed as a rectifier circuit and whose high-voltage connections can be connected to charging connections of a charging socket of the motor vehicle for connection to a device external to the high-voltage component in the form of an external charging station. The charger is also electrically connected to the high-voltage energy storage device, which can form a traction battery of the motor vehicle. The rectifier circuit of the charger is designed to convert an alternating current provided by the charging station into a direct current and supply it to the traction battery for charging. The charging station can, for example, be a wall box connected to a household electrical system.The insulation fault generation device can be used to prevent direct current from flowing into the household electrical system or alternating current from flowing from the household electrical system into a low-voltage electrical system of the motor vehicle connected to the charger in the event of a crash, for example in the event of an impact on the stationary motor vehicle connected to the charging station.

[0019] In a further development of the invention, the at least one insulation fault generation device has a circuit board arranged in the housing with at least two pins electrically insulated by the insulation barrier, wherein the pins form the contact elements. The circuit board can be fixed in the housing. The circuit board or printed circuit board can, for example, have printed conductors. The pins are pointed, electrically conductive elements which can, for example, be soldered onto the circuit board or pressed into the circuit board by means of a through-hole connection and are each electrically contacted by a conductor track. A first pin is electrically connected to one of the high-voltage connections, for example via a first electrical line connected to the corresponding conductor track. A second pin can be or is electrically connected to the further connection, for example via a second electrical line connected to the corresponding conductor track.When a force is applied to the force-absorbing area, the second pin, for example, is bent toward the first pin, thereby pushing through the insulation layer. As soon as the pins touch, the corresponding high-voltage terminal is connected to ground potential. This type of insulation generation device is particularly simple and cost-effective.

[0020] The embodiments presented with reference to the high-voltage component according to the invention and their advantages apply accordingly to the high-voltage electrical system according to the invention and to the motor vehicle according to the invention.

[0021] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own.

[0022] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. Fig. 1 a schematic representation of a high-voltage component of a high-voltage electrical system of a motor vehicle in normal operation; Fig. 2. The high-voltage component according to Fig. 1 in the event of a crash.

[0023] In the figures, identical and functionally identical elements are provided with the same reference numerals.

[0024] Fig. 1 shows a high-voltage component 1 for a high-voltage electrical system of an electrified motor vehicle. The high-voltage component 1 can, for example, be a charger, which can be electrically connected on the input side to charging connections of a charging socket of the motor vehicle and on the output side to a high-voltage energy storage device of the motor vehicle. The high-voltage component 1 has an electronic circuit 2, which in the case of the charger is a rectifier circuit for converting an alternating current provided by an external charging station and supplied to the motor vehicle via the charging socket into a direct current for charging the high-voltage energy storage device. The electronic circuit 2 is arranged in a housing interior 3 of a housing 4 of the high-voltage component 1. The housing interior 3 is enclosed by a housing wall 5 of the housing 4.High-voltage terminals 6a, 6b, which are connected to the electronic circuit 2, are arranged in a first partial area 5a of the housing wall 5. The electronic circuit 2 is arranged in a first partial area 3a of the housing interior 3.

[0025] A second partial area 5b of the housing wall 5 and a second partial area 3b of the housing interior 3 form a force absorption area 7, which is designed to absorb an accident-related force 8 and to convert the associated impact energy into deformation energy. Fig. The dashed line 9 shown in Figure 1 shows the partial area 5b' of the housing wall 5 deformed as a result of the force 8. In order to be able to bring about a safe state for the high-voltage component 1 in the event of an accident, the high-voltage component 1 has an insulation fault generation device 10. The insulation fault generation device 10 can generate an insulation fault due to an accident, which in the example shown here is generated between one of the high-voltage connections 6a and another connection A, in the form of a ground connection 11 of the high-voltage component 1 connected to a ground potential M. Such an insulation fault in the form of a short circuit between the high-voltage connection 6a and the ground connection 11 can be detected, for example, by an insulation monitor of the high-voltage vehicle electrical system (not shown here).The insulation fault generation device 10 has a first contact element 12, which is electrically connected to the high-voltage connection 6a, and a second contact element 13, which is electrically connected to the further connection A, i.e., here, to the ground connection 11. The contact elements 12, 13 can be designed, for example, as pointed, pin-like elements. An insulation barrier 14, for example, a mica layer, is arranged between the first contact element 12 and the second contact element 13, which normally galvanically separates the contact elements 12, 13 and thus the high-voltage connection 6a and the ground connection 11.

[0026] The second contact element 13 is arranged at least partially in the force absorption area 7. The deformed partial area 5b' of the housing wall 5 transmits, as in Fig.2, the deformation energy is transferred to the second contact element 13 and bends it toward the first contact element 12. In doing so, the second contact element 13 destroys the insulation barrier 14, for example, by crushing or squashing the mica layer. As a result, the contact elements 12, 13 are in electrically conductive contact and establish an electrical connection between the high-voltage terminal 6a and the ground terminal 11, through which a fault current flows, generating the insulation fault.

Claims

[1] High-voltage component (1) for a high-voltage electrical system of a motor vehicle, comprising: - an electronic circuit (2), - a housing (4) in which the electronic circuit (2) is arranged, - high-voltage connections (6a, 6b) connected to the electronic circuit (2) for connection to a device external to the high-voltage component, and, - at least one passive insulation fault generation device (10) arranged in the housing (4) for deliberately generating an insulation fault between one of the high-voltage terminals (6a) and a further terminal (A) in the event of an accident-related force (8) acting on the high-voltage component (1), comprising a first contact element (12) which is electrically connected to the high-voltage terminal (6a), a second contact element (13) which is electrically connected or connectable to the further terminal (A) and which is arranged at least in part in a force-absorbing region (7) of the housing (4), and an insulation barrier (14) arranged between the first contact element (12) and the second contact element (13), wherein the second contact element (13) is designed to absorb the accident-related force (8) acting on the force-absorbing region (7),to bridge the insulation barrier (14) and to contact the at least one first contact element (12) at least temporarily to generate the insulation fault., [2] High-voltage component (1) according to claim 1, characterized by that the high-voltage component (1) is a charger of the motor vehicle, the electronic circuit (2) of which is designed as a rectifier circuit and the high-voltage connections (6a, 6b) of which can be connected to charging connections of a charging socket of the motor vehicle for connection to a charging station external to the vehicle. [3] High-voltage component (1) according to claim 1 or 2, characterized by that the insulation barrier (14) is a physical insulation layer, in particular a mica layer, which can be destroyed for bridging by the at least one second contact element (13). [4] High-voltage component according to one of the preceding claims, characterized bythat the further connection (A), to which the second contact element (13) is electrically connected, is designed as a ground connection (11) of the high-voltage component (1) and the at least one insulation fault generation device (10) is designed to generate a body short between the high-voltage connection (6a) and the ground connection (A) as the insulation fault. [5] High-voltage component according to one of claims 1 to 3, characterized by that the further terminal (A), to which the second contact element (13) is electrically connected, is designed as the other high-voltage terminal (6b) and the at least one insulation fault generating device (10) is designed to generate a short circuit between the high-voltage terminals (6a, 6b) of the high-voltage component (1) as the insulation fault. [6] High-voltage component according to one of claims 1 to 3, characterized bythat the further connection (A), to which the second contact element (13) can be electrically connected, is designed as an earth connection and the at least one insulation fault generating device (10) is designed to generate an earth fault between the high-voltage connection (6a) and the earth connection as the insulation fault. [7] High-voltage component (1) according to one of the preceding claims, characterized by that the at least one insulation fault generating device (10) has a circuit board arranged in the housing (4) with at least two pins electrically insulated via the insulation barrier (14), wherein the pins form the contact elements (12, 13). [8] High-voltage electrical system for a motor vehicle with at least one high-voltage component (1) according to one of the preceding claims. [9] High-voltage electrical system according to claim 8, characterized bythat the high-voltage vehicle electrical system has a monitoring device which is designed to detect an insulation fault deliberately generated by the at least one insulation fault generating device (10) and to initiate a protective measure. [10] Motor vehicle with a high-voltage electrical system according to claim 8 or 9, wherein the at least one high-voltage component (1) is arranged in a deformation zone of the motor vehicle.

Images