DE102019200503A1 - Circuit device and method for controlling a self-discharge of a respective electrical energy store in at least one electrical component of a motor vehicle and corresponding motor vehicle - Google Patents

Abstract

The invention relates to a circuit device (S) for controlling a self - discharge of a respective electrical energy store (16) of at least one electrical component (15) of a motor vehicle (10), the at least one component (15) for receiving an electrical supply voltage (U) for it The respective power supply is connected to an electrical system (11) of the motor vehicle (10) and a central control device (23) is provided for controlling the self-discharge, which is set up to trigger the respective self-discharge to the at least one electrical component (15) to signal a predetermined signaling. The invention provides that the control device (23) is set up to carry out a signal transmission to the at least one component (15) via the electrical on-board electrical system (11) as signaling for triggering, and for this purpose the supply voltage (11) in the on-board electrical system (11) U), and the at least one component (15) is set up to start self-discharge if the modulation of the supply voltage (U) fulfills a predetermined triggering criterion (21).

Description

The invention relates to a circuit device, as can be provided in a motor vehicle, in order to trigger self-discharge or self-discharge of the local electrical energy store in at least one electrical component of the motor vehicle if the motor vehicle is involved in a crash (collision). The invention also includes a method for triggering self-discharge in the at least one component, and a motor vehicle which has the circuit device according to the invention.

A high-voltage electrical system can be provided in a hybrid vehicle or a purely electrically driven electric vehicle, in which a supply voltage greater than 60 volts is provided for supplying energy to at least one electrical component of the motor vehicle, for example an inverter. In such a vehicle electrical system, the vehicle electrical system voltage or supply voltage can be supported or fed by a central energy store, for example an electric battery. In the case of a high-voltage electrical system, it can be a high-voltage battery. The supply voltage is usually a direct voltage or DC voltage (DC - direct current). The on-board electrical system for distributing the supply voltage can have an electrical bus system (power bus), which can be configured, for example, on the basis of at least one cable per electrical pole (positive pole or negative pole) and / or at least one busbar per electrical pole. As an electrical component, the inverter of a traction drive of the motor vehicle can be connected to an electrical system, for example, in the manner mentioned. Furthermore, at least one electrical component can be connected, which can be responsible, for example, for the electrical charging of the central energy store of the motor vehicle and / or an electrical component for temperature control of a coolant and / or for air conditioning the passenger compartment of the motor vehicle. Additionally or alternatively, for example, a DC-DC converter for supplying a low-voltage electrical system, for example a 12-volt electrical system, can be provided as the electrical component.

An electrical vehicle electrical system, in particular a high-voltage vehicle electrical system, should be designed to be crash-proof. In addition to the mere deformation in the direction of the obstacle and in the direction of the passenger compartment, this also means that the electrical components of the motor vehicle must be discharged. The electrical components must preferably be able to take over this discharge themselves, that is to say a self-discharge or self-discharge of a respective local electrical energy store must be made possible in each electrical component. Such an energy store can be, for example, a local smoothing capacitor and / or buffer capacitor and / or a separate buffer battery for the respective component. This is because an electrical component can have, for example, a capacitor for supporting and / or filtering the received supply voltage of the vehicle electrical system. In particular, an inverter, such as a pulse-controlled inverter, is to be mentioned here as an electrical component, which can control a three-phase machine for vehicle traction.

The self-discharge can be carried out in an electrical component by a discharge circuit, which can be based, for example, on one or more electrical resistance elements and one or more electrical and / or mechanical and / or electromechanical switches. The discharge circuit or at least some parts thereof can be located on a printed circuit board which can be arranged in the component. The local energy store, for example a capacitor, can be located at a separate location in the electrical component.

In order to signal an electrical component that it is to trigger its own discharge, that is to say to activate its discharge circuit in order to discharge the local electrical energy store electrically, for example to discharge a capacitor, a communication link must be established from a central control device which detects, for example, a crash recognizes, be provided towards each electrical component to be controlled. In the event of a crash, however, there is a risk that such a communication connection will be interrupted before a trigger signal triggering the self-discharge could be successfully transmitted to the at least one electrical component.

From the DE 10 2016 103 829 A1 and the DE 10 2016 115 823 A1 it is known that in a motor vehicle at least one switch can be provided in its electrical system, which can interrupt an electrical connection in the electrical system. In this way, an uncontrolled current flow can be prevented, for example, in the event of a crash. To trigger the switching elements in the vehicle electrical system, powerline communication can be provided via live lines of the vehicle electrical system.

From the DE 10 2005 036 174 A1 it is known that in the event that a crash signal is present, a battery to be protected is only separated from the vehicle electrical system if the crash signal is via a predetermined minimum duration exceeds a minimum threshold. This prevents false triggering.

The object of the invention is to initiate a self-discharge of at least one electrical component in a motor vehicle from its local electrical energy store by a central control device.

The object is solved by the subject matter of the independent claims.

Advantageous embodiments of the invention are described by the dependent claims, the following description and the figures.

The invention provides a circuit device for controlling said self-discharge of a respective electrical energy store of at least one electrical component of a motor vehicle. The invention is based on the fact that the at least one component for receiving an electrical supply voltage for its respective energy supply is connected to an electrical system of the motor vehicle. The at least one component receives the electrical power for its own operation from the vehicle electrical system. Each of the at least one electrical component can have a discharge circuit for self-discharge of a respective energy store of the component, as is known per se from the prior art. To control the self-discharge, a central control device is provided according to the circuit device in the motor vehicle, which is set up to signal the triggering of the respective self-discharge to the at least one electrical component by means of a predetermined signaling. In other words, a central control device, for example a control unit, in the event that the self-discharge of the local energy store of the at least one component has to be triggered in the motor vehicle, can trigger or signal this by means of a predetermined type of signaling in the at least one component .

In order to make this signaling reliable, i.e. to secure the triggering or the transmission of the information for triggering the self-discharge from the central control device to the at least one component, the invention provides that the control device is set up to transmit a signal for the triggering of the at least one component not via a separate communication line, but via the electrical vehicle electrical system itself and for this purpose to modulate the supply voltage in the vehicle electrical system. In other words, no additional communication line is provided. Instead, the on-board electrical system itself is used as the communication line, i.e. the plus line and the minus line of the on-board network. Since the supply voltage is already present in the on-board electrical system, it is modulated to transmit the information relating to the triggering, that is to say changed over time. The at least one component in which the self-discharge is to be triggered is set up to start the self-discharge if the modulation of the supply voltage fulfills a predetermined triggering criterion. In other words, the at least one component can monitor the supply voltage, in particular its time profile, and, in the event that the supply voltage fulfills the triggering criterion, start self-discharge, that is to say, for example, control the discharge circuit accordingly. The modulation of the supply voltage means that the supply voltage is temporarily changed around its mean or nominal value with an AC voltage signal. This AC voltage signal can be generated by the central control device.

The advantage of the invention is that the information for triggering the self-discharge is transmitted via the vehicle electrical system, which, due to its construction, in particular the thickness of the lines, has proven to be particularly robust with regard to the impact of a crash. In addition, there is the advantage that no separate communication line has to be laid in the motor vehicle.

The invention also includes embodiments which result in additional advantages.

In one embodiment, said trigger criterion comprises that a predetermined trigger signal is modulated onto the supply voltage. In other words, in order to trigger or start the self-discharge, the control device must modulate an explicit or explicit trigger signal onto the supply voltage. This prevents false triggering, such as could be caused by an interference signal in the vehicle electrical system. For this purpose, the trigger signal can have a coding, because this cannot occur accidentally in the case of an interference signal.

In one embodiment, the trigger criterion comprises that a predetermined okay signal is absent in the supply voltage. In other words, in order to prevent self-discharge, the control device has to send out the OK signal continuously or at predetermined times. The triggering criterion starts the self-discharge if the at least one Component no longer receives or is missing or not detected in the supply signal in the supply voltage. This has the advantage that, in the event of an interruption in a line of the vehicle electrical system, when electrical signal transmission between the central control device and the at least one component becomes impossible, precisely this interruption leads to self-discharge or triggers it.

The provision of the trigger signal and the absence of the OK signal can also be combined, providing robust protection against false tripping.

In one embodiment, the triggering criterion comprises the said OK signal being absent for a predetermined minimum period of time. For example, the minimum time period can be in a range from 10 milliseconds to 2 seconds. This has the advantage that a single missing OK signal does not trigger self-discharge for a period shorter than the minimum period. For example, this can compensate for the influence of a temporary disturbance in the supply voltage.

In one embodiment, said central control device is set up to carry out the modulation of the supply voltage by means of an averaging-free alternating voltage signal. In other words, the mean voltage value of the supply voltage is not changed by the modulation or remains unchanged. This has the advantage that a potential change in the vehicle electrical system, as could be caused by the modulation, is avoided.

In one embodiment, the described discharge circuit is provided in the at least one electrical component for said self-discharge of the local energy store, which is set up to connect electrical poles of the energy store via at least one discharge resistor. In other words, there is at least one electrical component, namely the at least one discharge resistor, through which an electrical current flows only if the discharge circuit is triggered, ie the self-discharge is to be carried out. It is therefore advantageously not waited for the energy store of the component to discharge itself by continued operation of the component. The electrical resistance value of the at least one discharge resistor is preferably smaller overall than an electrical resistance of the electrical component, as is found in normal operation of the electrical component. As a result, the discharge time of the energy store is shorter than in the event that the energy store is discharged solely by continuing operation of the electrical component.

In one embodiment, the central control device is set up to trigger the respective self-discharge in the at least one electrical component if a crash signal is received from a collision sensor device. For example, the crash signal can be received from an airbag control unit of the motor vehicle. Coupling the collision sensor device with the control device results in the advantage that the time delay between the detection of a crash and the triggering of the self-discharge is small, i.e. the self-discharge takes place when a start of the crash is sensed, before an electrical line of the vehicle electrical system is then, for example, still during the crash destroyed or interrupted, making communication impossible.

In one embodiment, a predetermined communication protocol for bus communication is provided for said modulation of the supply voltage. This has the advantage that the at least one component can be addressed individually or specifically via the vehicle electrical system. In other words, addressed or recipient-specific communication is therefore preferably provided.

The invention also includes a motor vehicle which is set up according to the invention. In other words, the motor vehicle according to the invention has an electrical vehicle electrical system for distributing a supply voltage and at least one electrical component connected to the vehicle electrical system, which has its own energy store, for example a capacitor, in order to smooth and / or filter the received supply voltage, for example. An overall embodiment of the circuit device according to the invention is provided in the motor vehicle according to the invention.

The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

The operation of the circuit device according to the invention results in a method which is also part of the invention. The method according to the invention serves to trigger a self-discharge of a respective energy store in at least one electrical component in a motor vehicle. The method assumes that the at least one component for its energy supply receives an electrical supply voltage from an electrical system of the motor vehicle. In other words, it is the supply voltage around the operating voltage or vehicle electrical system voltage of the electrical vehicle electrical system. In particular, it can be a high voltage (high voltage - electrical voltage greater than 60 volts). In the method according to the invention, it is provided that in the at least one component the self-discharge from its local or own energy store is triggered by a central control device via the on-board electrical system by means of modulating the supply voltage. In the manner described, this has the advantage that no additional or separate communication line has to be laid between the central control device and the at least one component. The control device is therefore an element of the motor vehicle that is different from the at least one component and is connected to the at least one component via the electrical system.

The invention also includes embodiments of the method according to the invention which have features as have already been described in connection with the embodiments of the control device according to the invention. For this reason, the corresponding embodiments of the method according to the invention are not described again here.

The invention also includes combinations of the features of the described embodiments.

• 1 eine schematische Darstellung einer Ausführungsform des erfindungsgemäßen Kraftfahrzeugs mit einer Ausführungsform der erfindungsgemäßen Versorgungsvorrichtung; und
• 2 eine schematische Darstellung eines Energiespeichers mit einer Entladeschaltung, wie er in einer elektrischen Komponente des Kraftfahrzeug von 1 bereitgestellt sein kann.

Exemplary embodiments of the invention are described below. This shows:

• 1 a schematic representation of an embodiment of the motor vehicle according to the invention with an embodiment of the supply device according to the invention; and
• 2nd a schematic representation of an energy store with a discharge circuit, as it is in an electrical component of the motor vehicle from 1 can be provided.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and that further develop the invention independently of one another. Therefore, the disclosure is intended to include combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention that have already been described.

In the figures, the same reference numerals designate elements that have the same function.

1 shows a motor vehicle 10th , which can be a motor vehicle, in particular a passenger car or truck, or a passenger bus or a motorcycle. In the motor vehicle 10th can an electrical system 11 be provided, via which an electrical supply voltage U , in particular a DC voltage, from an electrical voltage source 12th can be generated. The voltage source 12th can comprise, for example, an electric battery and / or a generator. With the electrical system 11 can be, in particular, a high-voltage electrical system in which the supply voltage U is greater than 60 volts. The electrical system 11 can be an electrical positive lead 13 and an electrical negative lead 14 have, which can be provided or built, for example, on the basis of at least one cable and / or at least one busbar. Between the plus line 13 and the negative lead 14 can the electrical supply voltage U through the voltage source 12th generated or provided.

To the electrical system 11 can have at least one electrical component 15 be connected. Examples of such an electrical component 15 are: a pulse inverter for operating an electrical machine and / or an air conditioning device for the motor vehicle 10th . The at least one electrical component 15 can from the electrical system 11 the supply voltage for their operation U received in order to maintain the electrical power for operation. Any electrical component 15 can have its own local energy storage 16 have, which can be formed for example on the basis of an electrical capacitor.

In the event of a motor vehicle crash 10th one is interested, each locally in the energy store 16 use or dissipate stored electrical energy.

In the motor vehicle 10th For this purpose, a circuit device S can be implemented to ensure rapid discharge of electrical energy in the event of a crash. This can be done in every component 15 a discharge circuit 17th be provided. An example of how a discharge circuit is shown 17th at least one switching element 18th and at least one electrical discharge resistor 19th can have that between electrical poles of the energy storage 16 can be switched. A switching logic 20 the discharge circuit 17th in the event that a trigger criterion 21 is satisfied, the switching element 18th switch electrically conductive and thereby a discharge current 22 from the Energy storage 16 the component 15 due to the electrical discharge resistance 19th cause what the in the energy storage 16 stored energy is broken down or discharged.

To trigger or start this self-discharge using the discharge circuit 17th can be a central control device 23 in the motor vehicle 10th be provided, the control device 23 can be implemented, for example, on the basis of a control unit. The control device 23 can trigger the respective self-discharge in the at least one component 15 a crash signal 24th received and then the discharge of the energy storage 16 in the at least one component 15 trigger or command. This happens in the motor vehicle 10th via the electrical system 11 itself, in particular via the plus line 13 and the minus line 14 . For this purpose it can be provided that an electrical, averaging-free alternating voltage signal 25th as a trigger signal to the supply voltage U is modulated. An example of the course of the AC voltage signal 25th is in 1 symbolically represented over time t in a course diagram. The control device 23 can be used to modulate the AC signal 25th via a respective decoupling capacitor 26 with the plus line 13 and the negative lead 14 be electrically connected. As a result, the supply voltage U as DC voltage not on the control device 23 Act. A PLC control element can be used for stamping 27 be provided (PLC - Power Line Communication). A communication protocol for bus communication can be provided for transmitting a trigger command.

In addition or as an alternative to the trigger signal, it can also be provided in the crash-free case, by means of the AC voltage signal 25th an OK signal on the supply voltage U to modulate.

The switching logic 20 in the respective component 15 can be used as a trigger criterion 21 provide, for example, that the trigger signal in the supply voltage U recognizable or must be detected. Additionally or alternatively, the absence of the OK signal can be used as a trigger criterion 21 be provided.

Is via the electrical system 11 by modulating the supply voltage U triggering the discharge circuit 17th in one component 15 triggered, for example, the at least one switching element is triggered in the manner described 18th switched electrically conductive and thereby the discharge current 22 by the at least one discharge element or the at least one discharge resistor 19th headed.

2nd illustrates an example of a construction of an energy store 16 as he is in a component 15 can be provided. It shows how the energy storage 16 as a capacitor winding 28 Can have foils. For the sake of clarity, there are only three capacitor windings 28 provided with a reference number. 2nd shows in a section 29 a transverse view of a layer structure of the capacitor winding 28 , being between electrically conductive foils 30th a polarity and an electrically conductive film 31 the other polarity is an insulation film 32 can be provided. The foils can wrap in the capacitor 28 for example, each wound into a roll. Surrounding metallic teeth 33 can with a deformation of a housing 34 of the energy storage 16 in the capacitor winding 28 cut and electrically bridge several layers of the alternating plus and minus foils and thereby create a short circuit.

In the energy storage 16 can the discharge circuit 17th be embedded. To check the supply voltage U can be a connecting cable 34 for the discharge circuit 17th out of the case 34 led out or misplaced.

Overall, the examples show how a crash-proof, highly dynamic clamp discharge of high-voltage components in an electric, hybrid or fuel cell vehicle can be provided by the invention.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016103829 A1 [0006]
• DE 102016115823 A1 [0006]
• DE 102005036174 A1 [0007]

Claims (10)

Circuit device (S) for controlling a self-discharge of a respective electrical energy store (16) of at least one electrical component (15) of a motor vehicle (10), the at least one component (15) for its respective energy supply to an electrical system (11) of the motor vehicle ( 10) for receiving an electrical supply voltage (U) and for controlling the self-discharge a central control device (23) is provided which is set up to trigger the triggering of the respective self-discharge to the at least one electrical component (15) by means of a predetermined signaling Signal, characterized in that the control device (23) is set up to carry out a signal transmission to the at least one component (15) via the electrical on-board electrical system (11) as signaling for triggering, and for this purpose the supply voltage (11) in the on-board electrical system (11) U) modulate, and the at least one component te (15) is set up to start the self-discharge if the modulation of the supply voltage (U) fulfills a predetermined trigger criterion (21). Circuit device (S) after Claim 1 , wherein the trigger criterion comprises that a predetermined trigger signal is modulated onto the supply voltage (U). Circuit device (S) according to one of the preceding claims, wherein the triggering criterion (21) comprises that a predetermined in-order signal is absent in the supply voltage (U). Circuit device (S) after Claim 3 , wherein the trigger criterion (21) comprises that the OK signal is absent for a predetermined minimum period of time. Circuit device (S) according to one of the preceding claims, wherein the control device (23) is set up to carry out the modulation of the supply voltage (U) by means of an averaging-free alternating voltage signal (25). Circuit device (S) according to one of the preceding claims, wherein in the at least one electrical component (15) for self-discharge a discharge circuit (17) is provided which is set up to connect electrical poles of the energy store (16) via at least one discharge resistor (19) connect to. Circuit device (S) according to one of the preceding claims, wherein the control device (23) is set up to trigger the respective self-discharge if a crash signal (24) is received from a collision sensor device. Circuit device (S) according to one of the preceding claims, wherein a predetermined communication protocol for bus communication is provided for the modulation. Motor vehicle (10) with an electrical vehicle electrical system (11) for distributing a supply voltage (U) and with at least one electrical component (15) connected to the vehicle electrical system (11), which has its own energy store (16), characterized in that in the Motor vehicle (10) a circuit device (S) according to one of the preceding claims is provided. Method for triggering a self-discharge of a respective energy store (16) in at least one electrical component (15) of a motor vehicle (10), the at least one component (15) supplying an electrical supply voltage (U) from an electrical vehicle electrical system (11) for its energy supply Motor vehicle (10) receives, characterized in that in the at least one component (15) the self-discharge of its energy store (16) is triggered by a central control device (23) via the on-board electrical system (11) by means of a modulation of the supply voltage (U).

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