Switching device for a multiphase high-voltage on-board network of an electric motor vehicle, electronic control unit and motor vehicle

Abstract

This invention relates to a switching device for a multi-pole high-voltage on-board network for an electric motor vehicle. The switching device includes at least one first switch (S1) electromechanically disposed on a first pole of at least one high-voltage memory and at least one second switch (S2) electromechanically disposed on a second pole of at least one high-voltage memory. The first and second switches are differently configured and designed to jointly satisfy a defined first requirement, and at least the first switch is configured such that it individually satisfies at least one defined second requirement. The common defined first requirement is the ability to separate the two poles, i.e., the joint separation of the first and second poles from the charging source. A third switch (S3) is provided between the first pole and the first switch and between the second pole and the second switch, respectively. The third switch is a pyrotechnic switch in the event of a short circuit. The invention also relates to an electronic control unit for a motor vehicle and an electric motor vehicle.

Description

Technical Field

[0001] This invention relates to a switching device for a multi-pole high-voltage on-board network for electric motor vehicles. The invention also relates to an electronic control unit and an electric motor vehicle. Background Technology

[0003] Current focus is on in-vehicle networks used in electric vehicles, particularly high-voltage in-vehicle networks. Such networks employ electrical switches (e.g., relays or contactors) that connect multiple in-vehicle network components (e.g., drive motors or high-voltage battery modules) to power lines. In the event of a fault or malfunction in one in-vehicle network component, a fault current can flow as an overcurrent through the associated power lines, potentially further damaging the power lines to the faulty component and the faulty component itself.

[0004] Therefore, as is known in the prior art, a switching device is used that can disconnect and isolate faulty vehicle network components from the vehicle network in the presence of overcurrent. Such a switching device may, for example, have a relay or contactor and a fuse. Here, the focus when designing a contactor or relay is usually on high breaking capacity. Summary of the Invention

[0005] The purpose of this invention is to provide a reliable and inexpensive switching device for high-voltage vehicle-mounted networks in motor vehicles, which simultaneously meets multiple specified requirements.

[0006] The objective is achieved by a switching device, an electronic control unit, and a motor vehicle having the features of the present invention. Advantageous embodiments of the invention are described in the specification and accompanying drawings.

[0007] Therefore, the objective is achieved by a switching device for a multi-pole high-voltage on-board network for electric motor vehicles, the switching device comprising at least one first electromechanical switch disposed on a first pole of at least one high-voltage memory and at least one second electromechanical switch disposed on a second pole of at least one high-voltage memory, the first and second switches being configured differently and designed to jointly satisfy a defined first requirement, and at least the first switch being configured such that the first switch alone satisfies at least one defined second requirement, the first requirement being a bipolar separation capability, i.e., the joint separation of the first and second poles from the charging source, the second requirement being a separation capability under load below the operating current limit, the second switch being configured such that the second switch alone satisfies a defined third requirement, the third requirement being a vibration-free switching capability, and a third switch being disposed between the first pole and the first switch and between the second pole and the second switch, the third switch being a pyrotechnic switch in the event of a short circuit.

[0008] The objective is also achieved by an electronic control unit for a motor vehicle, which is used to operate at least two different electromechanical switches of the switching device according to the invention.

[0009] The objective is also achieved by an electric motor vehicle, which includes a switching device according to the invention.

[0010] The switching device for a multi-pole (e.g., bipolar) high-voltage on-board network for electric motor vehicles according to the present invention has an electromechanical first switch for a first pole (e.g., positive pole) and an electromechanical second switch for a second pole (e.g., negative pole), each switch being differently configured and designed to collectively satisfy a first requirement (e.g., bipolar separation capability), and the first switch being configured such that it individually satisfies at least one second requirement (e.g., separation capability under load below a defined operating current limit). In other words, the "first switch" and the "second switch" are two different switch types. Therefore, the "first switch" is the first switch type of the two switch types.

[0011] In an advantageous extension of the invention, the first and second switches are each provided with actuators that can be operated via low-voltage power supply, in particular to meet the common first requirement of bipolar separation capability, so as to connect or disconnect all (e.g., both) power lines of the high-voltage vehicle network.

[0012] In the embodiment of the invention, the second switch is configured such that the second switch alone satisfies at least one third requirement (e.g., vibration-free switching capability below a predetermined voltage difference threshold).

[0013] In another preferred embodiment of the invention, the first switch is further configured such that it automatically disconnects when the low-voltage power supply to the actuator fails.

[0014] In another preferred embodiment of the invention, the second switch is further configured such that it remains closed when the low-voltage power supply to the actuator fails.

[0015] In other words, the two switches (or switch types) satisfy different requirements on the one hand, and common requirements on the other hand.

[0016] This invention is based on the following considerations: Existing technology

[0017] To date, the same switch (“switching device”) is typically used for each switching position in high-voltage automotive networks, and each of these switches itself meets all the requirements for a switch in a high-voltage automotive network. To date, no targeted functional division as described in the subject matter of this invention has been implemented.

[0018] The following objectives should be achieved, in particular, by the present invention:

[0019] - Surge current tolerance during parallel switching;

[0020] - Surge current tolerance during normal pre-charge;

[0021] - Surge current tolerance during DC charging;

[0022] - Depending on operating conditions, keep power consumption below 20 watts;

[0023] - The reduction in contact resistance and therefore the ability to use high power;

[0024] -Despite internal insulation failures, the separation capability is still guaranteed (at least at 800V).

[0025] - Mechanical impact resistance.

[0026] Possible solutions for the first and second switches are illustrated, for example, in the applicant’s unpublished patent applications DE102020124784 and DE102020118308. These also constitute advantageous solutions in the embodiments. Attached Figure Description

[0027] The invention will now be explained in more detail with reference to preferred embodiments and the accompanying drawings. Wherein:

[0028] Figure 1 A schematic diagram showing an exemplary application of the entire switching device according to the present invention; and

[0029] Figure 2 Examples of preferred embodiments of the first and second switches of the switching device according to the present invention are shown.

[0030] In the accompanying drawings, the same elements and elements with the same function are given the same reference numerals. Detailed Implementation

[0031] exist Figure 1 The present invention describes a switching device 1 for a two-pole high-voltage on-board network for electric motor vehicles. This high-voltage on-board network has two high-voltage storage devices, HVS1 and HVS2, each with a rated voltage of approximately 400V. Additionally, the high-voltage on-board network has a switching matrix USM (which includes three additional switches), through which the two high-voltage storage devices HVS1 and HVS2 can be switched either in series or in parallel. Therefore, charging at 800V is permitted, especially when the vehicle is connected to a DC charging connector.

[0032] To charge at such high voltages or power (e.g., the operating current limit of approximately 1 kA), requirements specified for safety reasons must be met. The first requirement is, in particular, the common separation of the positive and negative terminals from the charging source (bipolar separation capability). The second requirement is separation capability below the operating current limit (on the order of 1 kA). The third requirement is vibration-free switching capability. Another requirement is the interruption of the high-voltage supply in the event of a failure of the actuator used to switch on and off the high-voltage supply (low-voltage supply) in a fault condition.

[0033] To date, known high-voltage vehicle networks have used the same type of switches to meet all these requirements, with each switch fulfilling all the requirements. This invention relates to the application of differently constructed switches that collectively meet all the requirements and, in this case, perform defined sub-functions.

[0034] To this end, an electromechanical first switch S1 is provided, which is connected to the positive (+) terminal of high-voltage memories HVS1 and HVS2, and an electromechanical second switch S2 is provided, which is connected to the negative (-) terminal of high-voltage memories HVS1 and HVS2. Switches S1 and S2 are configured differently and designed to satisfy a defined common first requirement, particularly bipolar separation capability, wherein only one of the two switch types (or the first switch S1 connected to the positive (+) terminal) is designed such that this switch type individually satisfies at least one defined second requirement. Preferably, the defined second requirement is separation capability below the operating current limit. Therefore, in terms of power, the second switch type, i.e., the second switch S2 connected to the negative terminal, can be configured with lower robustness and therefore lower cost compared to the first switch type (switch S1).

[0035] Conversely, the second switch type (or the second switch S2 assigned to the negative (-) terminal) is preferably configured such that it alone satisfies the defined third requirement, particularly vibration-free switching capability. Relatedly, the first switch type can be configured even more simply.

[0036] The two switch types, or switches S1 and S2, are respectively equipped with actuators A1 and A2 that can be operated via low-voltage power supply (12V) to connect or disconnect the power supply line of the high-voltage vehicle network.

[0037] The first switch S1 (or first switch type) is further configured such that it automatically disconnects when the low-voltage power supply to actuator A1 fails. Here, the first switch S1, for example, has a return spring F for disconnecting when the low-voltage power supply to actuator A1 fails, wherein actuator A1, especially the travel magnet, is powerless in the absence of current and therefore does not resist the return spring F (see also...). Figure 2 (Left side).

[0038] The second switch S2 (or second switch type) is further configured such that it remains closed when the low-voltage power supply to actuator A2 fails. Here, the second switch S2 does not have a return spring for disconnecting when the low-voltage power supply to actuator A2 fails, wherein actuator A2, especially a motor with a self-locking screw SP, remains in its current position without current (see also...). Figure 2 (Right side).

[0039] The two switches (or switch types) S1 and S2 thus satisfy different requirements on the one hand, and also satisfy common requirements on the other hand.

[0040] Optionally, a third switch S3 may be provided, which is in the form of a known pyrotechnic switch under short-circuit conditions.

[0041] Optionally, each switch of the switching matrix USM can have the same structural form as the second switch S2.

[0042] exist Figure 2 The text describes particularly advantageous implementation methods for each switch S1 and S2, or for each switch type.

[0043] The scheme for the first switch S1 is described on the left, and the scheme for the second switch S2 is described on the right. However, the present invention is not limited to these schemes for these two switch types.

[0044] Advantageous design of the first switch S1:

[0045] For example, Schaltbau's multi-contact contactors have the following characteristics:

[0046] - Separation capability below the operating current limit (approximately 1 kA);

[0047] - Approximately 50 microohms of contact resistance, approximately 5 watts of holding power;

[0048] - Automatically disconnects when 12V power supply fails.

[0049] Advantageous design of the second switch S2:

[0050] For example, the actuator from Sonceboz (featuring a single contact of a brushless DC motor):

[0051] - Connecting capability with voltage differences below 10V;

[0052] - Approximately 30 microohms of contact resistance, 0 watts of holding power;

[0053] - Keep closed in case of 12V failure;

[0054] - Mechanical shock resistance in the disconnected state.

[0055] Advantageous design of the optional third switch S3 (not described in more detail here, but pyrotechnic switches in short-circuit conditions are already widely known):

[0056] For example, Daicel's fire switch:

[0057] - Separation capability below approximately 15kA full short-circuit current;

[0058] - Contact resistance of approximately 30 microohms.

Claims

1. A switching device (10) for a multi-pole high-voltage on-board network for an electric motor vehicle, the switching device comprising at least one electromechanical first switch (S1) disposed on a first pole (+) of at least one high-voltage memory (HVS1, HVS2) and at least one electromechanical second switch (S2) disposed on a second pole (-) of at least one high-voltage memory (HVS1, HVS2), the first switch (S1) and the second switch (S2) being differently configured and designed to jointly satisfy a defined first requirement, and at least the first switch (S1) being configured such that the first switch alone... The first requirement of the definition is to satisfy at least one second requirement, the first requirement of the common definition is the separation capability of the bipolar poles, that is, the common separation of the first pole and the second pole from the charging source. The second requirement of the definition of the first switch (S1) is the separation capability under load below the operating current limit. The second switch (S2) is constructed such that the second switch alone satisfies the third requirement of the definition, the third requirement being the vibration-free switching capability. A third switch (S3) is provided between the first pole and the first switch and between the second pole and the second switch, the third switch being a pyrotechnic switch under short-circuit conditions.

2. The switching device according to claim 1, characterized in that, The third switch (S3) has a separation capability below a full short-circuit current of 15kA and a contact resistance of 30 microohms.

3. The switching device according to claim 1 or 2, characterized in that, The high-voltage vehicle network has two high-voltage memories (HVS1, HVS2) and a switching matrix (USM). The two high-voltage memories (HVS1, HVS2) can be switched in series or in parallel through the switching matrix.

4. The switching device according to claim 1 or 2, characterized in that, The first switch (S1) and the second switch (S2) are respectively equipped with actuators (A1, A2) that can be controlled by low-voltage power supply, so as to connect or disconnect the power supply line of the high-voltage vehicle network.

5. The switching device according to claim 4, characterized in that, The first switch (S1) is further configured such that it automatically disconnects when the low-voltage power supply to the actuator (A1) fails.

6. The switching device according to claim 4, characterized in that, The second switch (S2) is further configured such that it remains closed when the low-voltage power supply to the actuator (A2) fails.

7. The switching device according to claim 4, characterized in that, The first switch (S1) has a reset spring (F) for disconnecting when the low voltage power supply to the actuator (A1) fails, and the actuator (A1) does not resist the reset spring (F) when there is no current.

8. The switching device according to claim 4, characterized in that, The first switch (S1) has a return spring (F) for disconnecting when the low voltage power supply to the actuator (A1) fails, and the travel magnet of the actuator (A1) does not resist the return spring (F) when there is no current.

9. The switching device according to claim 4, characterized in that, The second switch (S2) does not have a reset spring for disconnecting when the low voltage power supply to the actuator (A2) fails, and the actuator (A2) remains in its current position when there is no current.

10. The switching device according to claim 9, characterized in that, The actuator (A2) used for the second switch is an electric motor with a self-locking screw (SP).

11. An electronic control unit (20) for a motor vehicle, the electronic control unit being used to operate at least two different electromechanical switches of a switching device (10) according to any one of claims 1 to 10.

12. An electric motor vehicle comprising a switching device (10) according to any one of claims 1 to 10.

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