Cancellation of transient overvoltage in energy on-board electrical system

Abstract

The invention relates to a vehicle (1) having an on-board electrical system (2) on which at least one consumer (3) can be supplied with electrical energy by means of a respective output stage circuit (4) and can be operated therefrom, the output stage circuit (4) having a supply input (6), the input voltage of which can be measured by means of a voltage measuring device (10), the power supply input (6) is electrically connected to the consumer output (8) via an electronic switch (7) and the vehicle (1) is designed to detect an overvoltage by means of measurement data measured by the voltage measuring device (10) and to then close the electronic switch (7) as a function of a current vehicle operating state if the electronic switch is previously open. The invention also relates to a method for eliminating transient overvoltage in an on-board power system (2) of a vehicle (1). In particular, the invention can be advantageously applied to electric vehicles, in particular partially or fully autonomous driving electric vehicles.

Description

Field of the Invention

[0001] The present invention relates to a vehicle having an on-board electrical network, on which at least one consumer can be supplied with electrical energy via an electronic switch and can thus be operated, wherein an input voltage can be measured by means of a voltage measuring device, and the vehicle is designed to recognize overvoltage and then close the electronic switch. The present invention further relates to a method for eliminating transient overvoltage in the on-board electrical network of a vehicle, the on-board electrical network having a power supply unit including a power supply input and a consumer output, an electronic switch being interposed between the power supply input and the consumer output, the consumer output being electrically connected to a consumer, and in this method, an input voltage is measured at the power supply input, and when an overvoltage or a potential overvoltage is recognized by means of the input voltage, if the electronic switch was previously open, the electronic switch is temporarily closed. The present invention can be advantageously applied in particular to electric vehicles, especially semi-autonomous or fully autonomous electric vehicles. Background Art

[0002] Overvoltage in the on-board electrical network of a vehicle can in particular cause component failures or even damage at the semiconductor or battery level and thus lead to the failure of highly available functions.

[0003] DE 197 42 391 C1 discloses a method for protecting an electronic controller in a motor vehicle, in which overvoltage pulses, especially load dump pulses, are detected, and one or more consumers are switched on when such an overvoltage pulse occurs. Thereby, the overvoltage pulse can be eliminated very quickly - still before the maximum value that the overvoltage pulse would reach without compensation - so as to protect the electronic circuits and controllers included in the motor vehicle. Thus, overvoltage protection can be achieved without the necessity of additional components. In addition, a device for implementing this method is provided.

[0004] DE 102 91 613 T5 discloses a system for eliminating overvoltage in the power supply of a vehicle, the system including: means for receiving a load, the means having low resistance characteristic parameters and high power consumption characteristic parameters; and a control section that selectively couples the means for receiving the load to the power supply device when the voltage of the power supply exceeds a preselected threshold.

[0005] DE 10 2010 040 864 A1 discloses a method for operating the on-board electrical network of a vehicle, the on-board electrical network including a first partial electrical network and a second partial electrical network, the method including the following steps: when a voltage peak in the first partial electrical network is recognized, transferring current from the first partial electrical network into the second partial electrical network. In addition, a control device and a control program are disclosed.

[0006] DE 10 2014 209 267 A1 discloses a heating device and a method for eliminating overvoltages in a first part of the on-board electrical system of an electrically drivable vehicle. The method includes the following steps: identifying an overvoltage or other information indicating an impending overvoltage event in the first part of the on-board electrical system, and in response thereto, closing the electrical connection between the electric heating device of the vehicle and the first part of the on-board electrical system to eliminate the overvoltage. SUMMARY OF THE INVENTION

[0007] The object of the present invention is to at least partially overcome the disadvantages of the prior art and in particular to provide improved possibilities for eliminating overvoltages in the energy on-board electrical system of a vehicle.

[0008] This object is solved by the features of the independent claims. Preferred embodiments can in particular be derived from the dependent claims.

[0009] This object is solved by a vehicle having an energy on-board electrical system on which at least one consumer can be supplied with electrical energy by means of a respective power supply unit (“output stage circuit”) and can thus be operated, wherein:

[0010] The output stage circuit has a power supply input whose input voltage can be measured by means of a voltage measuring device,

[0011] The power supply input is electrically connected to the consumer output via an electronic switch, and

[0012] The vehicle is designed to identify an overvoltage by means of the measurement data measured by the voltage measuring device and then, if the electronic switch was previously open, to close the electronic switch according to the current vehicle operating state.

[0013] The vehicle has the advantage that a particularly large number of, even safety-critical, consumers can be temporarily connected to the energy on-board electrical system and thus switched on or connected in order to conduct overvoltage pulses, whereby overvoltage pulses can be eliminated particularly effectively with little structural effort. Here, it is utilized that the selection of the consumers to be switched on and the type of switching on can be adapted to the current vehicle operating state, so that for example safety-critical consumers can also be temporarily switched on or can be temporarily switched on without a safety-critical reaction and / or violation of safety objectives occurring thereby.

[0014] The vehicle can for example be a vehicle with an internal combustion engine, a hybrid vehicle (e.g. a plug-in hybrid vehicle, PHEV) or a fully electric vehicle (e.g. a battery-operated vehicle, BEV). The vehicle can in particular be a partially autonomous or fully autonomous vehicle for which overvoltage elimination is particularly safety-critical.

[0015] The on-board electrical network can have a uniform on-board voltage or can have two or more partial on-board electrical networks with different on-board voltages, for example 12 V and 400 V.

[0016] The consumer can be supplied with electrical energy by means of a corresponding output stage circuit and can thus be operated, in particular including: the consumer is supplied with electrical energy via the output stage circuit and is then switched on or activated, while the consumer is switched off or deactivated during an interrupted energy supply via the output stage circuit. That is to say, the consumer is "stupid" in particular in the sense that the consumer can be switched on and off via the associated output stage circuit, but cannot switch itself on and off.

[0017] The output stage circuit obtains the supply voltage for the consumer connected via the consumer output via a supply input, since the supply input is electrically connected to the consumer output via an electronic switch. The electronic switch can be a semiconductor switch, in particular a power semiconductor such as a transistor, in particular a MOSFET. If the electronic switch is in its cut-off switching state (switch "open"), the current path between the supply input and the consumer output is interrupted. If the electronic switch is in its conducting switching state (switch "closed"), the current path between the supply input and the consumer output is electrically conductive.

[0018] The input voltage can be measured by means of a voltage measuring device, which can include: measuring the voltage regularly and transmitting the measured voltage value for further evaluation. Such a further configuration method is particularly advantageous because it is then possible not only to detect the threshold value of a warning overvoltage being reached or exceeded, but also to evaluate the voltage change, which can, for example, early on indicate a future potential overvoltage. The voltage measuring device can also be referred to as a "voltage sensor". In a particularly simple implementation, the voltage measuring device is configured as an overvoltage sensor, which only outputs or converts an output signal when the measured voltage reaches or exceeds the threshold value of a warning overvoltage. The overvoltage sensor can be, for example, a comparator or have a comparator.

[0019] A vehicle, in particular at least one data processing device of the vehicle, is designed to identify an (already occurred or possibly even future potential) overvoltage by means of the measurement data measured by the voltage measuring device, in particular including: evaluating the measured voltage value or identifying a change in the output signal of the overvoltage sensor.

[0020] Therefore, if the electronic switch was previously open, the electronic switch is closed according to the current vehicle operating state, in particular including: temporarily switching on a previously switched-off consumer according to the current vehicle operating state in order to eliminate the overvoltage. If the electronic switch is already closed, the electronic switch remains in the closed state or in a "forced" closed state.

[0021] In addition, with regard to the vehicle operating state, the on-board electrical network state caused by the driving situation and passenger use is relevant. Depending on the on-board electrical network state, some consumers must be excluded by the output stage circuit for overvoltage elimination or can alternatively be considered (e.g., steering at a standstill compared to steering during driving). The vehicle operating state can include directly measured or regulated vehicle information, such as size and status, as well as vehicle information derived therefrom.

[0022] One design solution is:

[0023] The vehicle has a data processing device (“status instance”), which is data-technologically coupled to the logic circuit of at least one output stage and reports the current vehicle operating state to this logic circuit, and

[0024] the logic circuit is connected to a voltage measuring device and an electronic switch and is designed to identify overvoltage by means of the measurement data measured by the voltage measuring device and then to keep the electronic switch open or to close the electronic switch according to the current vehicle operating state.

[0025] This achieves the advantage that the output stage circuit can autonomously identify overvoltage and automatically control the electronic switch. This enables particularly fast switching. A further expansion solution is that the logic circuit is designed, for example programmed, to convert the vehicle operating state into a corresponding or “matched” control or switching of the electronic switch, for example with regard to the duration of closing of the electronic switch.

[0026] A further expansion solution is that the circuit calls the vehicle operating state from the status instance when overvoltage is recognized.

[0027] A further expansion solution is that the logic circuit has a data memory that can be overwritten, into which the current vehicle operating state can be transferred from the status instance. This has the advantage that the current vehicle operating state already exists in the output stage circuit and thus enables autonomous and particularly fast switching of the electronic switch.

[0028] A further expansion solution is that the status instance and the logic circuit are data-technologically coupled to each other via a data bus system. A further expansion solution is that the status instance and the logic circuit are connected to each other via at least one dedicated signal line.

[0029] A further expansion solution is that the electronic switches of multiple output stage circuits can be controlled by a superior instance of the output stage circuit. This has the advantage that an independent logic circuit in the output stage circuit can be dispensed with. Such a superior instance is especially connected to the electronic switch via a corresponding signal or control line. This instance especially includes one (or more) functions of the output stage circuit.

[0030] One design solution is that the vehicle has a state instance, which:

[0031] Maintains the current vehicle operating state, is connected to an electronic switch and is technically coupled to the data of the voltage measuring device, and

[0032] Is designed to identify overvoltage by means of the measurement data measured by the voltage measuring device and then keep the electronic switch open or close the electronic switch according to the current vehicle operating state.

[0033] The following advantages are achieved in this way, namely, an independent logic circuit in the output stage circuit can be dispensed with and the above-described functions of the logic circuit are integrated into the state instance (which can also be referred to as the "state and switching instance" at this time). That is, such a state instance maintains the current vehicle operating state, monitors the presence of overvoltage, and is designed, for example, programmed to control the electronic switch according to the current vehicle operating state.

[0034] One design solution is that the vehicle has at least one state instance, which is coupled to a plurality of output stage circuits, that is, according to the embodiment, is coupled to the logic circuit of the output stage circuit or directly to the electronic switch of the output stage circuit.

[0035] One design solution is that the vehicle operating state includes at least one speed of the vehicle, in particular includes the difference between the stationary and moving states of the vehicle. This difference has the following advantages, that is, even safety-critical consumers can be temporarily operated for overvoltage elimination when stationary, and these consumers should not be operated for overvoltage elimination during driving. For example, the operation of the electric braking system is non-critical when stationary, but not so during driving. Other possible states or information of the vehicle operating state can be, for example, seat occupancy, GPS coordinates, acceleration, especially the on / off state of the consumer, configuration details, cover open or closed, etc.

[0036] One design solution is that the vehicle operating state at least includes the stationary, slow driving and fast driving of the vehicle. In this way, a finer difference can be achieved for temporarily operating unmanipulated consumers for overvoltage elimination. For example, the electric steering system can be operated for a short time when stationary and driving slowly, and this will not be safety-critical or will not be noticed by vehicle passengers, but not so during fast driving. Slow driving can be understood, for example, as driving at a speed not higher than 20 to 30 km / h, and fast driving is correspondingly understood as driving at a higher speed. But more than two speed gradings can also be used. In addition, the speed threshold can depend on the type of consumer.

[0037] One design solution is that the vehicle (such as a logic circuit or a state instance) is designed to control an open electronic switch according to the current vehicle operating state, so that the electronic switch:

[0038] remain in its open switching state,

[0039] close for such a short time that the consumer does not perform a consumer action, or

[0040] close for such a long time that the consumer performs a consumer action, if this consumer action is not safety-critical and not noticed by the vehicle user.

[0041] This achieves the following advantage, namely, being able to react to overvoltage particularly effectively and flexibly without incurring safety losses and comfort losses.

[0042] The open electronic switch remaining in its open switching state means that the consumer is not used to eliminate overvoltage but remains switched off. This can be the case, for example, when the operation of this consumer in the current driving state would imply a safety loss or a comfort loss.

[0043] Closing the open electronic switch for such a short time that the consumer does not perform a consumer action includes: the consumer is switched on, but only for such a short time that, although the consumer consumes current, for example, for starting electrical structural elements and / or electronic devices, it does not perform its function, for example, does not cause a steering movement or does not produce a braking effect. Since overvoltage is a very transient process, a short switching-on duration is sufficient, if necessary, to limit the overvoltage. A further refinement is to control the electronic switch additionally or alternatively based on the perceptibility of the manipulation by the user.

[0044] Particularly effective is to close the open electronic switch for such a long time that the consumer performs a consumer action (such as a steering movement or a braking effect), if this consumer action is not safety-critical and not noticed by the vehicle user. For example, it is also possible to operate safety-critical consumers, such as an electric braking system or an electric steering system, for a longer time when stationary, because, for example, the implementation of the braking process is neither safety-critical nor noticed by the passengers at this time.

[0045] One design is to be able to adjust the type of control according to the magnitude of the overvoltage. This achieves the following advantage, namely, being able to provide stronger elimination for higher overvoltages and thus being able to react to overvoltage particularly flexibly. If, for example, the overvoltage is small, it is possible to forego switching on certain consumers or to switch them on for a shorter time than when the overvoltage is high.

[0046] One design option is that the output stage circuit has an additional voltage measuring device or a second voltage measuring device, which is designed to measure the output voltage present at the consumer output. This results in the advantages of redundancy and evaluation of the switching state, for example also for verifying the successful switching of the electronic switch in addition to overvoltage elimination, for example for functional checks.

[0047] One design option is that the electronic switch is a component of an electronic fuse device (also referred to as an "E-Fuse") or such an electronic fuse device.

[0048] One design option is that the vehicle is the vehicle according to one of the above claims, wherein the output stage circuit is integrated into the current distributor. In particular, when the electronic switch is an E-Fuse, this can be implemented particularly economically and compactly, because the E-Fuse that already exists as a protection element can also be used as an electronic switch. The current distributor typically has a power supply input and a plurality of consumer outputs, which are protected in particular by the E-Fuse. A further expansion option is that the logic circuit - if present - is integrated into the current distributor. A further expansion option is that the status instance is integrated into the current distributor.

[0049] The above task is also solved by a method for eliminating transient overvoltages in the on-vehicle electrical network of a vehicle, which on-vehicle electrical network has an output stage circuit including a power supply input and a consumer output, an electronic switch being interposed between the power supply input and the consumer output, the consumer output being electrically connected to a consumer, wherein, in this method, the input voltage is measured at the power supply input, and when an overvoltage or a potential overvoltage is identified by means of the input voltage, if the electronic switch was previously open, the electronic switch is temporarily closed according to the current vehicle operating state. The method can be constructed similarly to the vehicle and vice versa, and has the same advantages. Description of the Drawings

[0050] The above-mentioned characteristics, features and advantages of the present invention and the ways and means of realizing them become clearer and easier to understand in connection with the following schematic description of the embodiments, and the embodiments are further described in conjunction with the drawings.

[0051] Figure 1 A simplified diagram of a vehicle 1 having an on-vehicle electrical network 2 is shown, on which at least one consumer 3 can be supplied with electrical energy by means of a corresponding output stage circuit 4 and can thus operate. The output stage circuit 4 can form part of a current distributor 5. Detailed Description of the Embodiments

[0052] The output stage circuit 4 has a power supply input 6, which is electrically connected to the consumer output 8 via an electronic switch in the form of an E-Fuse 7. The consumer 3 is connected, for example via a cable 9, to the consumer output 8. An input voltage is present at the power supply input 6, which input voltage nominally corresponds to the vehicle electrical system voltage, but transient overvoltages can also occur on this vehicle electrical system voltage. The input voltage can be measured by means of a first voltage measuring device 10. A second voltage measuring device 11 is connected between the E-Fuse 7 and the consumer output 8 in order to measure the voltage there. If the E-Fuse 7 is closed and thus switched to conducting, the consumer 3 is supplied with the vehicle electrical system voltage and then switched on. If the E-Fuse 7 is open and thus switched to interrupted, the consumer 3 is disconnected from the vehicle electrical system voltage and then switched off. Thus, the switching of the E-Fuse causes the switching on or off of the consumer 3.

[0053] The E-Fuse 7 is connected to a logic circuit 12 via a control line, and the logic circuit 12 can send control signals for selectively opening and closing the E-Fuse 7 onto the control line. The logic circuit 12 is furthermore connected to the first voltage measuring device 10 and the second voltage measuring device 11 via signal lines, in particular data lines, via which the measurement signals or measurement data output by the voltage measuring devices 10, 11 can be transmitted to the logic circuit 12. The logic circuit 12 is furthermore connected, in a data-technical manner, for example via a data bus 13, to an instance external to the output stage circuit (“status instance” 14), and the logic circuit 12 keeps this instance informed about the current vehicle operating state. Alternatively, the functions of the logic circuit 12 can be integrated into the status instance 14, so that the separate logic circuit 12 can be dispensed with.

[0054] If an overvoltage or a potential overvoltage is identified at the power supply input 6 by means of the voltage measuring device 10 or the logic circuit 12, the logic circuit 12 decides, depending on the current vehicle operating state, whether the E-Fuse 7, which has hitherto been open, should remain open or be temporarily closed, and in particular also decides for how long the E-Fuse should be closed in order to limit the overvoltage. In particular, the duration of the conductive connection of the E-Fuse 7 can depend on the driving speed of the vehicle 1, for example whether the vehicle is stationary, driving slowly or driving fast. This can also depend on the magnitude of the overvoltage.

[0055] Of course, the invention is not restricted to the embodiments shown.

[0056] In general, “a” etc. can be understood as singular or plural, in particular in the sense of “at least one” or “one or more” etc., provided that this is not explicitly excluded, for example by an expression such as “exactly one” etc.

[0057] The numerical specifications may exactly include the numbers being specified or may include common tolerance ranges, provided that this is not explicitly excluded.

[0058] List of reference signs

[0059] 1 Vehicle

[0060] 2 On-board electrical network for energy

[0061] 3 Consumer or output stage

[0062] 4 Output stage circuit

[0063] 5 Current distributor

[0064] 6 Power supply input

[0065] 7 E-Fuse

[0066] 8 Consumer output

[0067] 9 Cable

[0068] 10 First voltage measuring device

[0069] 11 Second voltage measuring device

[0070] 12 Logic circuit

[0071] 13 Data bus

[0072] 14 Status instance

Claims

1. A vehicle (1) having an on-board energy electrical network (2) on which at least one consumer (3) can be supplied with electrical energy by means of a respective output stage circuit (4) and can thus be operated, The output stage circuit (4) has a power supply input (6) the input voltage of which can be measured by means of a voltage measuring device (10), The power supply input (6) is electrically connected via an electronic switch (7) to a consumer output (8), and The vehicle (1) is designed to recognize an overvoltage by means of measurement data measured by the voltage measuring device (10) and then, if the electronic switch was previously open, to close the electronic switch (7) according to the current vehicle operating state.

2. The vehicle (1) according to claim 1, wherein: The vehicle (1) has a status instance (14) which is data-technologically coupled to a logic circuit (12) of the output stage circuit (4) and reports the current vehicle operating state to the logic circuit (12), and The logic circuit (12) of the output stage circuit (4) is connected to the voltage measuring device (10) and the electronic switch (7) and is designed to recognize an overvoltage by means of measurement data measured by the voltage measuring device (10) and then to keep the electronic switch (7) open or to close the electronic switch according to the current vehicle operating state.

3. The vehicle (1) according to claim 1, wherein, The vehicle (1) has a status instance (14) which: Maintains the current vehicle operating state, is connected to the electronic switch (7) and is data-technologically coupled to the voltage measuring device (10), and Is designed to recognize an overvoltage by means of measurement data measured by the voltage measuring device (10) and then to keep the electronic switch (7) open or to close the electronic switch according to the current vehicle operating state.

4. The vehicle (1) according to one of claims 2 to 3, wherein, The vehicle (1) has at least one status instance (14) coupled to a plurality of output stage circuits (4).

5. The vehicle (1) according to any one of claims 2 to 4, wherein, The driving state at least includes the stationary state and the driving state of the vehicle (1).

6. The vehicle (1) according to claim 5, wherein, The driving state at least includes the stationary state, the slow driving state and the fast driving state of the vehicle (1).

7. Vehicle (1) according to one of claims 2 to 6, wherein, The vehicle (1) is designed to control an open electronic switch (7) according to the current vehicle operating state such that the electronic switch: Remains in its open switching state, Closes for such a short time that the consumer (3) does not perform a consumer action, or Closes for such a long time that the consumer (3) performs a consumer action if this consumer action does not have a safety-critical effect and is not perceived by the user of the vehicle (1).

8. The vehicle (1) according to claim 7, wherein, The type of control can be adjusted according to the magnitude of the overvoltage.

9. The vehicle (1) according to one of the preceding claims, wherein, The output stage circuit (4) has another voltage measuring device (11) which is designed to measure the output voltage present at the consumer output (8).

10. The vehicle (1) according to one of the preceding claims, wherein, The electronic switch (7) is a component of an electronic fuse device or is an electronic fuse device.

11. The vehicle (1) according to one of the preceding claims, wherein, The output stage circuit (4) is integrated into a current distributor (5).

12. A method for eliminating transient overvoltages in the on-vehicle electrical network (2) of a vehicle (1), said on-vehicle electrical network having an output stage circuit (4) comprising a power supply input (6) and a consumer output (8), an electronic switch (7) being interposed between said power supply input and the consumer output, said consumer output being electrically connected to a consumer (3), wherein, In the method: The input voltage is measured at the power supply input (6), and when an overvoltage or a potential overvoltage is identified by means of the input voltage, if the electronic switch was previously open, the electronic switch (7) is temporarily closed according to the current vehicle operating state.

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