EP3688854A1

EP3688854A1 - Multi-line supply unit for a vehicle control device

Info

Publication number: EP3688854A1
Application number: EP18759071.6A
Authority: EP
Inventors: Hartmut Schumacher; David Voigt
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-09-26
Filing date: 2018-08-15
Publication date: 2020-08-05
Also published as: DE102017217003A1; CN111133650A; JP2020535785A; MX2020003025A; US11177655B2; US20210159694A1; CN111133650B; KR102568231B1; KR20200060740A; JP6993514B2; WO2019063186A1

Abstract

The invention relates to a multi-line supply unit (1A) for a vehicle control device, having at least two supply lines (S1, S2) which are each connected at the input to at least one vehicle voltage source and are joined at the output in a common node (KP), and a protective device (3A) which comprises in each of the at least two supply lines (S1, S2) at least one first protective diode (Dvs1, Dvs2) which is looped into the at least two supply lines (S1, S2) in the conducting direction between the at least one vehicle voltage source and the node (KP). The invention also relates to a method for operating such a multi-line supply unit (1A). In the method, at least one switching element (Svs1, Svs2) is looped into each of the at least two supply lines (S1, S2) parallel to the at least one protective diode (Dvs1, Dvs2), wherein an evaluation and control unit (10A) senses and evaluates a line voltage (VS1, VS2) at the inputs of each of the at least two supply lines (S1, S2) and a supply voltage (VP), protected against polarity reversal, at the common node (KP) and actuates the switching elements (Svs1, Svs2) in the at least two supply lines (S1, S2) via corresponding actuation signals (Svs1_CTL, Svs2_CTL) depending on the evaluation.

Description

Description title

The invention is based on a multi-strand supply unit for a vehicle control unit according to the preamble of independent claim 1. The subject of the present invention is also an operating method for such a multi-strand supply unit. Electronic control devices in a vehicle are usually powered by a first switchable terminal (KL 15 R), which is connected in a first ignition lock position (radio) with a power source, and / or via a second switchable terminal (KL 15), which in a second ignition lock position (ignition) is connected to a power source. If it concerns ECUs with a "SIEP MODE", which are supplied with power even when the vehicle is turned off, they are supplied with energy via a permanent plus terminal (KL 30), which is connected to an energy source independent of the ignition lock position. A supply current from the permanent plus terminal is almost zero when the vehicle is parked in active "SIep mode". In non-active "SIep" mode, ie in the controller's normal operating mode, the required supply current is provided from the continuous plus terminal In another variant, in the normal operating mode of the controller, the first switchable terminal and / or the second switchable terminal are redundant In addition to the supply redundancy, this has the advantage that the switched supply strands can also be used for redundant wake-up signaling for the corresponding control device The primary wake-up function and / or the SIeep Mode can be controlled by means of suitable bus activities or bus commands The supply lines provided are polarity protected in the control unit and linked to "wired-or". This can it can be ensured that no damage can occur in the control unit in the case of reverse polarity of one or more supply strings. The "wired-or-connection" of the power supply lines in the control unit also serves to supply the control unit with redundant power during normal operating mode.Today, silicon diodes have been used as reverse polarity protection in the continuous current range up to 2 A. This leads to voltage drops of up to an IV and to a power loss of up to 2 W. In improved systems with lower voltage drops, Schottky diodes are used, allowing a continuous current of up to 4 A to be displayed well, with voltage drops below 0.6 V resulting in a power loss of can lead to up to 2.4W.

The multi-strand supply unit for a vehicle control unit with the features of independent claim 1 and the operating method for a multi-strand supply unit have the advantage that the voltage drops for the polarity reversal and thus the power losses of the individual supply strands during continuous power operation can be significantly reduced by the parallel to the protection diodes connected switching elements , In this case, the protective diodes in each supply line advantageously provide a static and / or dynamic polarity reversal protection and a regenerative protection. As a result, rising current requirements of future, larger control devices for safety systems, assistance systems, etc., which are used in particular in vehicles with at least partially autonomous driving functions, can be operated in an advantageous manner. In addition, embodiments of the multi-strand supply unit for a vehicle control unit take into account not only the polarity reversal protection but also further filter circuits for subsequent switching regulators.

Embodiments of the multi-strand supply unit for a Fahrzeugsteuerge- device are preferably designed as two-strand supply units, usually a first supply line via a permanent plus terminal of an ignition is permanently powered and a second supply line is powered by a switchable terminal of the ignition with energy. In addition, in embodiments of the multi-strand supply unit for Vehicle control unit in sleep mode of the corresponding control unit via the supply lines only currents below 100 μΑ.

Furthermore, embodiments of the multiple-train supply unit for a vehicle control unit monitor the individual supply lines, in particular to detect a lack of a supply line or a short circuit of a supply line. Embodiments of the multiple-strand supply unit for a vehicle control unit are advantageously designed such that an energy store can be used as output load. This energy store is preferably designed as a capacitor and can provide energy for a defined period of usually a few 100 to 10 ms to maintain the control unit supply in the event of break-in, short-circuit and / or interruption of the multi-string supply unit without large parts of this energy being returned to the multiple-string supply unit. be fed.

In an advantageous manner, embodiments of the multi-strand supply unit for a vehicle control device prevent a permanent regeneration from one supply strand to another supply strand when the supply strands have different voltage levels. Even with dynamic processes, in particular with AC voltage components on the DC voltages of the supply lines, a dynamic energy recovery is limited in an advantageous manner. In addition, embodiments of the multi-string supply unit for a vehicle control device include protective measures against positive or negative pulses on the supply lines and in particular allow unbalanced clamping or limiting the positive and negative pulses.

Embodiments of the present invention provide a Mehrstrangversor- supply unit for a vehicle control unit, with at least two supply lines, which are each connected at the input to at least one vehicle voltage source and merged at the output in a common node, and a protection device which in the at least two supply lines each comprises at least one first protective diode, which in the forward direction between the at least one driving voltage source and the node in the at least two supply lines is looped. In this case, in each case at least one switching element is connected in parallel to the at least one protective diode in the at least two supply lines. In addition, an evaluation and control unit detects at the inputs of the at least two supply lines each a strand voltage and at the common node a polarity protected supply voltage and evaluates them. Depending on the evaluation, the evaluation and control unit controls the switching elements in the at least two supply lines via corresponding drive signals.

In addition, an operating method for such a multi-strand supply unit is proposed, which detects and evaluates at the inputs of the at least two supply strands each a strand voltage at the common node a reverse polarity protected supply voltage. In this case, the switching elements in the at least two supply lines are controlled as a function of the evaluation via corresponding control signals.

In this case, the evaluation and control unit can be understood as meaning an electrical device, such as a control unit, in particular a driver assistance control unit, an integrated safety system or an airbag control unit, which detects detected sensor signals, such as video signals, radar signals, lidar signals, temperature signals, infrared signals, Position signals, acceleration signals, pressure signals, yaw rate signals, etc., and / or processed voltages or currents and / or evaluates. The evaluation and control unit may have at least one interface, which may be formed in hardware and / or software. In the case of a hardware-based configuration, the interfaces can be part of a so-called system ASIC, for example, which contains a wide variety of functions of the evaluation and control unit. However, it is also possible for the interfaces to be separate, integrated circuits or to consist at least partly of discrete components. In a software training, the interfaces may be software modules that are present, for example, on a microcontroller in addition to other software modules. A computer program product with program code, which is stored on a machine-readable carrier such as a semiconductor memory, a hard disk memory or an optical memory, is also of advantage and is used to perform the evaluation when the program is executed by the evaluation and control unit.

Advantageous improvements of the multi-strand supply unit specified in independent claim 1 for a vehicle control unit and of the operating method specified in independent claim 16 for such a multi-strand supply unit are possible due to the measures and developments listed in the dependent claims. It is particularly advantageous that the evaluation and control unit, the individual

Can compare strand voltages with each other and / or with the reverse polarity protected supply voltage and depending on the comparisons via a hardware control unit can generate the drive signals for the at least one switching element. A hardware control unit is understood below to mean an electrical circuit which is constructed from discrete electronic or electrical components or components, so that very fast evaluation processes for detecting internal conditions and short switching times can be implemented. This means that the hardware control unit via corresponding contacts and connections can be connected directly to the inputs of the supply lines and the common node and can be powered by the common node with energy. The hardware control unit or parts of the hardware control unit can be switched on or off via a sleep input. The evaluation and control unit can close the at least one switching element via the drive signals generated by the hardware control unit when a difference between the corresponding string voltage and the reverse polarity protected supply voltage at the common node exceeds a predetermined first threshold value. Thereby, a voltage drop across the corresponding supply line and thus the power loss can be reduced in an advantageous manner. In addition, the evaluation and control unit can open the at least one switching element via the drive signals generated by the hardware control unit when the difference between the corresponding phase voltage and the reverse polarity protected supply voltage at the common node falls below a predetermined second threshold or negative. As a result, a return from the common node over the closed switching element in the affected supply line can be prevented. In addition, a difference between the first threshold and the second threshold may be set via a variable resistor in the hardware controller. As a result, a hysteresis for the switching elements in the individual supply lines can advantageously be specified in order to improve the stability of the switching decision. Normally, all switching elements are identical and are operated with identical hysteresis. In this case, a common setting of the hysteresis for all switching elements is sufficient. Alternatively, a separate hysteresis can be specified for each switching element. For the adjustment of the hysteresis, the internal resistance of the switching element, the stability of the switching decision and the return current detection level in the associated supply line can be taken into account. Thus, the stability of the switching decision can be made dependent on the individually to be detected feedback current and adjusted to the internal resistance of the switching elements used.

In an advantageous embodiment of the multi-strand supply unit, the evaluation and control unit may comprise a computer unit which individually checks the at least two supply lines as a function of predetermined conditions. In this case, the computer unit for checking the at least two supply lines generate at least one control signal and output to the hardware control unit, which can generate and output the corresponding drive signals for the at least one switching element in response to the at least one control signal. To detect line breaks or short circuits or other problems or to check the quality of a supply line, the switching elements in the individual supply lines can be opened briefly and the reactions of the individual phase voltages and the reverse polarity protected supply voltage at the common node detected and evaluated. As a measure of the quality, for example, an internal resistance of the corresponding supply line can be determined and evaluated. Here, the quality of the supply line is inversely proportional to the internal resistance, ie the quality of the supply line decreases with increasing internal resistance. In a further advantageous embodiment of the multi-strand supply unit, the computer unit can generate a warning message and / or make an error storage and output via an audible and / or optical output unit and / or via a diagnostic interface, if the computer unit a line break and / or a problem and / or recognizes a poor quality in the at least two supply lines. As a result, the driver can be warned in good time and take over control of at least semi-automatic functions again or the problem can be corrected at the next service. For example, error type, error location and error time can be stored until the next service.

In a further advantageous embodiment of the multi-strand supply unit, in each case one field-effect transistor can form the at least one first protective diode and the at least one switching element in the at least two supply strings. Preferably, the field effect transistors are as These P-channel MOS

Field effect transistors (PMOSFET) carried out, which are conductive in the forward direction via a bulk diode between the drain and source. This allows easy control by a positive source-gate voltage. In order to reduce a pulse load of the at least one switching element, at least one second protective diode can be arranged in the at least two supply lines in each case parallel to the at least one first protective diode and to the at least one switching element. The at least one second protection diode protects the corresponding switching element, in particular in an embodiment as a PMOSFET, against high negative voltage pulses which, for example, during switching operations, such as switching off an arranged parallel to the control unit inductance, such as seat heating, window heating, etc., on the supply line can arise. The at least one second protection diode can preferably be designed as a powerful suppressor diode (TSV) with a breakdown voltage in the range of 24V to 40V. In addition, the outputs of the at least two supply strands can each be connected to the common node or jointly at the common node via at least one third protective diode to ground, which is adapted to reduce a positive pulse load of the at least two supply strands. In this case, the at least one third protective diode can be a negative occurring at the common node Limit the voltage to a predefined value and trigger an electrical vehicle fuse in the event of reverse polarity in the event of a faulty line switch. For example, the negative voltage may be limited to a value in the range of -0.3V to -1.2V. The supplementation of the circuit with the central at least one third protection diode serves to protect the multiple-strand supply device against positive pulses including a load dump. If there is a positive pulse load in one of the supply strands, the pulses are clamped or limited by the at least one third protection diode. The at least one third protective diode can preferably be designed as a high-performance suppressor diode (TSV) with a breakdown voltage in the range from 30 V to 42 V. By means of the at least one second protective diode and the at least one third protective diode, the pulse loads of the switching elements can be reduced, so that cheaper transistor types with a smaller source-drain strength and low volume resistance and a smaller area requirement can advantageously be used. The static reverse polarity safety of the supply line is not adversely affected by the additional at least one second protection diode and the at least one third protection diode. In addition, the use of the at least one second protective diode and the at least one third protective diode results in the possibility of asymmetrical clamping or limitation of negative or positive supply pulses, whereby the size or absorption performance of the negative clip element is decoupled from that of the positive clip element can. Furthermore, the unidirectional clamping at the common node advantageously combines extended protection against reverse polarity in the event of a defect of a switching element in the supply line with the aim of triggering the line fuse before damage occurs in the control device.

In a further advantageous embodiment of the multi-strand supply unit, the inputs of the at least two supply lines can each be connected and attenuated by means of at least one RC element which comprises an ohmic resistance and a capacitance. In addition, the outputs of the at least two supply strands can each be individually in front of the common node or together at the common node by at least one RC element, which comprises an ohmic resistance and a capacity, connected to ground and attenuated. As a result, inductive interference voltages, for example, are attenuated by the supply line, which result from a connection to the vehicle battery in addition to a resistor. This can be prevented in an advantageous manner that switching operations cause interference voltages in the individual supply lines and at the common node, which exceed Störgrenzwerte and can jeopardize an optimal control of the switching elements. The dimensioning of the RC elements depends on the equivalent inductances and currents of the individual supply strings.

In a further advantageous embodiment of the multi-strand supply unit, the common node can be connected via a passive filter with the control unit. Preferably, the passive filter can have an energy reserve, which can compensate for a brief voltage dip. The energy reserve may preferably comprise a capacitor. In a particularly advantageous embodiment, the passive filter can be designed as a multi-strand T filter. In each case, a first filter inductance can be looped in in the at least two supply lines between the switching element and the common node, and a common second filter inductance can be connected between the common node and a filter output. This embodiment allows a symmetrical connection of the supply lines to the subsequent control unit and enables cut-off frequencies of less than 20 kHz in order to support subsequent switching regulators of the control unit with respect to a power supply rejection ratio (PSSR) for interference frequencies above the control frequency.

In an advantageous embodiment of the operating method, the individual phase voltages can be compared with each other and / or with the reverse polarity protected supply voltage and depending on the comparisons the control signals for the at least one switching element via the hardware control unit are generated.

In a further advantageous embodiment of the operating method, the at least two supply strands can be checked individually during operation as a function of predetermined conditions. The review of the mini- For example, at least two supply strings can take place at predetermined time intervals. Additionally or alternatively, the at least two supply strings can be checked individually if a voltage difference between the phase voltages exceeds a predetermined amount.

In a further advantageous embodiment of the operating method, the at least one switching element of the supply line to be tested can be opened and the reactions of the corresponding strand voltage and the reverse polarity protected supply voltage at the common node can be detected and evaluated at a first check of the individual supply strands. In this case, a line interruption in the supply line to be tested can be detected if the corresponding phase voltage is below a predetermined minimum limit when the switching element is open, for example in a voltage range between 0 V and 6 V. After the check, the opened switching element is closed again and the next supply line can be checked by the corresponding switching element is opened. The kurzeitige review of a supply line by opening the associated switching element endangers the control unit supply in any way, since the affected supply line via the first protection diode and additionally via the parallel second protection diode can still ensure the control unit supply.

In a further advantageous embodiment of the operating method can be closed at a second review of at least two supply lines only the corresponding switching element of the supply line to be tested, and the switching elements of the other supply strands can be opened, and the reaction of the corresponding strand voltage in loaded supply line to be tested can be detected and be evaluated. In this case, a problem which is caused for example by poor contacts or too high a replacement resistance of the supply line to be tested, be recognized in the loaded supply line to be tested if the corresponding phase voltage is below a predetermined load limit with closed switching element. In a further advantageous embodiment of the operating method, the individual phase voltages can be compared with each other and each with a vehicle voltage of the connected vehicle voltage source. Based on the comparison, an internal resistance of the corresponding supply string can be deduced. Likewise, it can be concluded by evaluating all phase voltage differences before and after the shutdown of the corresponding switching element to the internal resistance of the supply line when a known change in current occurs.

In a further advantageous refinement of the operating method, a warning message can be generated and / or fault storage can be carried out and output via an audible and / or optical output unit and / or via a diagnostic interface, if a line interruption and / or a problem and / or poor quality in the at least two supply strings is detected. In this case, the poor quality can be recognized, for example, by the fact that the internal resistance exceeds a predetermined limit. As a result, the driver can be warned in good time and take over control of at least semi-automatic functions again or the problem can be corrected at the next service. For example, error type, error location and error time can be stored until the next service.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. In the drawing, like reference numerals denote components or elements that perform the same or analog functions.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic circuit diagram of an embodiment of a multi-line power supply unit for a vehicle control device according to the present invention having a first embodiment of a protection device. FIG. 2 shows a schematic circuit diagram of a second exemplary embodiment of an inventive IV power supply unit for a vehicle control unit with a first exemplary embodiment of a protective device.

3 shows a schematic circuit diagram of a second exemplary embodiment of a protective device for the multi-strand supply units according to the invention from FIGS. 1 and 2, which is connected to an energy source.

Fig. 4 shows a schematic circuit diagram of the protective device of Fig. 3, which is connected to two power sources.

5 shows a schematic circuit diagram of a third exemplary embodiment of a protective device for the multiple-strand supply units according to the invention from FIGS. 1 and 2.

6 shows a schematic circuit diagram of a third exemplary embodiment of an inventive IV power supply unit for a vehicle control unit with a fourth exemplary embodiment of a protective device.

7 shows a schematic circuit diagram of an exemplary embodiment of a hardware control unit for an evaluation and control unit of the IV power supply unit according to the invention for a vehicle control device from FIG. 6.

FIG. 8 shows a characteristic diagram of voltages during a normal operation of the vehicle power supply unit according to the invention for a vehicle control device from FIG. 1 with the protective device from FIG. 3.

FIG. 9 shows a characteristic diagram of different sizes of the inventive IV supply unit for a vehicle control unit from FIGS. 1 and 2 with the protective device from FIG. 4, wherein the multiple-string supply device has different DC components and is disturbed by a 1 kHz sinusoidal interference voltage. 10 shows a characteristic diagram of different sizes of the multi-line power supply unit according to the invention for a vehicle control device from FIGS. 1 and 2 with the protective device from FIG. 4, wherein the multi-line power supply device has different DC components.

Embodiments of the invention

As can be seen from FIGS. 1 to 7, the illustrated exemplary embodiments of a multi-line supply unit 1A, 1B, IC for a vehicle control device 2 each comprise at least two supply lines S1, S2, which are each connected at the input to at least one vehicle voltage source B, B1, B2 and on Output are combined in a common node KP, and a protective device 3A, 3B, 3C, 3D, which in the at least two supply lines Sl, S2 each comprise at least one first protective diode Dvsl, Dvs2, which in the forward direction between the at least one vehicle voltage source B, Bl , B2 and the node KP in the at least two supply lines Sl, S2 is looped. In this case, at least one switching element Svsl, Svs2 is connected in parallel to the at least one protective diode Dvsl, Dvs2 in the at least two supply lines Sl, S2, wherein an evaluation and control unit 10A, 10B, IOC at the inputs of the at least two supply lines Sl, S2 respectively a line voltage VS1, VS2 and at the common node KP detects a polarity protected supply voltage VP and evaluates. Depending on the evaluation, the evaluation and control unit 10A, 10B, IOC controls the switching elements Svsl, Svs2 in the at least two supply lines Sl, S2 via corresponding drive signals Svsl_CTL, Svs2_CTL.

In the illustrated embodiments, the multi-strand supply unit 1A, 1B, IC is in each case designed as a two-strand supply unit with two supply lines Sl, S2. In alternative embodiments, not shown, the multi-strand supply unit 1A, 1B, IC may also have more than two supply lines Sl, S2.

As can also be seen from FIGS. 1 to 7, in the illustrated supply strings S 1, S 2, the first protective diodes Dvsl, Dvs 2 are designed for static and / or dynamic polarity reversal protection, a security of supply with open switching element Svsl, Svs2 and used for a backfeed protection. In order to reduce a voltage drop in the supply direction, the switching elements Svsl, Svs2, which are arranged parallel to the first protective diodes Dvsl, Dvs2, are used in the precautionary strands S1, S2. The evaluation and

Control unit 10A, 10B, IOC compares the individual phase voltages VS1, VS2 with each other and / or with the reverse polarity protected supply voltage VP and generates the control signals Svsl_CTL, Svs2_CTL for the switching elements Svsl, Svs2 as a function of the comparisons via a hardware control unit 12A, 12B, 12C. For this purpose, the hardware control unit 12A, 12B, 12C uses connections to the two supply lines Sl, S2 via the terminals VS1JN, VS2JN and to the common node KP via the terminal VPJN. The hardware control unit 12 A, 12 B, 12 C is supplied with the reverse polarity protected supply voltage VP and ground GND via the terminals VPJN and GND.

In a normal operation, the evaluation and control unit 10A, 10B, IOC closes the switching elements Svsl, Svs2 via the hardware control unit 12A, 12B, 12C when a difference between the corresponding string voltage VS1, VS2 and the reverse polarity protected supply voltage VP at the common

Junction KP exceeds a predetermined first threshold. The evaluation and control unit 10A, 10B, IOC opens the switching elements Svsl, Svs2 via the hardware control unit 12A, 12B, 12C when the difference between the corresponding string voltage VS1, VS2 and the reverse polarity protected supply voltage VP at the common node KP a predetermined second threshold falls below or becomes negative. As further seen in FIGS. 1, 2 and 6, a difference between the first threshold and the second threshold is adjustable via a variable resistor Rhys in the hardware controller 12A, 12B, 12C. In the normal case, a first switching element Svsl is closed for real vehicle supplies when a first drive signal Svsl_CTL has a low value. If the first drive signal Svsl_CTL is processed in a special driver for the first switching element Svsl, the first switching element Svsl can close depending on the definition of either a logic "high" or a logic "low" signal. This is the case when a first phase voltage VS1 is greater than a differential voltage. is from the reverse polarity protected supply voltage VP and a predetermined hysteresis. Otherwise, the first switching element Svsl remains open. A second switching element Svs2 is normally closed for real vehicle supplies when a second drive signal Svs2_CTL has a low value. If the second drive signal Svs2_CTL is processed in a special driver for the second switching element Svs2, depending on the definition, either logic "high" or logic "low" signals can close the second switching element Svsl. This is the case when a second phase voltage VS2 is greater than a difference between the reverse polarity protected supply voltage VP and a predetermined hysteresis. Otherwise, the second switching element Svs2 remains open. The switching hysteresis advantageously prevents the switching elements Svsl, Svs2 from oscillating since, after the corresponding switching element Svsl, Svs2 has closed, the reverse polarity-protected supply voltage VP increases only slightly below the supplying string voltage VS1, VS2 due to the low switch resistance. The switching hysteresis can either be preset for the structurally identical switching elements Svsl, Svs2. In the illustrated performance games, the hysteresis can be adjusted via the optional resistor Rhys. Decisive for the adaptation are the internal resistances of the switching elements Svsl, Svs2, the phase current height in the supply direction a desired stability of the switching decision and a return current detection level in the corresponding supply line Sl, S2.

As is further apparent from FIGS. 1, 2 and 6, the evaluation and control unit 10A, 10B, IOC comprises a computer unit 14A, 14B, 14C which individually checks the two supply lines S1, S2 in dependence on predetermined conditions. For checking the two supply strings Sl, S2, the computer unit 14A, 14B, 14C generates corresponding control signals STR1_CTL, STR2_CTL and outputs them to the hardware control unit 12A, 12B, 12C. The hardware control unit 12A, 12B, 12C generates the corresponding drive signals Svsl_CTL, Svs2_CTL in response to the control signals STR1_CTL, STR2_CTL and outputs them to the two switching elements Svsl, Svs2 or their drivers.

In the embodiments illustrated in FIGS. 1 and 6, the hardware control unit 12A, 12C and the computer unit 14A, 14C of the evaluation and Control unit 10A, IOC designed as a unit and can be arranged in the region of the switching elements Svsl, Svs2 or executed as part of the control unit. In the embodiment shown in FIG. 2, the hardware control unit 12B and the computer unit 14B of the evaluation and control unit 10B are arranged separately from one another. As can also be seen from FIG. 2, the hardware control unit 12 B is arranged in the area of the switching elements Svsl, Svs2, and the computer unit 14 B is integrated in the control unit 2. In addition, in the exemplary embodiment illustrated in FIG. 2, the multi-strand supply unit 1B for a vehicle control unit 2 is coupled to a switching regulator 2.1 of the control unit 2 via a passive filter 20 to the common node KP of the multi-strand supply unit 1B. The passive filter 20 attenuates disturbances of the vehicle electrical system, in particular sinusoidal horns over 5 kHz to 20 kHz, suppresses the reaction of the switching regulator 2.1 to the electrical system and ensures the supply of the control unit 2 in the case of short-term dips of the reverse polarity protected supply voltage VP. Referring to Fig. 6, an advantageous embodiment 20C of the passive filter 20 will be described below.

3 to 6, the inputs of the two supply lines Sl, S2 in the illustrated embodiments of the protective device 3B, 3C, 3D respectively by an RC element, which has a resistance Rsl, Rs2 and a capacitance Csl, Cs2, connected to ground GND and attenuated. As is further apparent from FIGS. 3 and 4, the outputs of the two supply lines Sl, S2 in the illustrated embodiment are connected and attenuated together at the common node KP by an RC element to ground GND, which comprises an ohmic resistor RP and a capacitor CP , The embodiment shown in Fig. 4 differs only by the number of vehicle power sources B, Bl, B2 of the embodiment shown in Fig. 3. As can also be seen from FIG. 3, the protective device 3B of the multi-strand supply unit 1A is connected to only one vehicle energy source B, which is represented as a permanent vehicle voltage VB via a first line, which is represented by a first ohmic resistance Ril and a first line inductance Lil, the first supply line Sl and as guided via a second line, which is represented by a second ohmic line resistance Ri2 and a second line inductance Li2, and supplied via an ignition lock ZS vehicle voltage VB supplies the second supply line S2. As can also be seen from FIG. 4, the protective device 3B of the multi-strand supply unit 1A is connected to two vehicle energy sources B1, B2. In this case, a first vehicle energy source Bl supplies as a permanently first vehicle voltage VB1 via a first line, which is represented by a first ohmic line resistance Ril and a first line inductance Lil, the first supply line Sl, and a second vehicle energy source B2, as supplied via a second line, which is represented by a second ohmic line resistance Ri2 and a second line inductance Li2, and via the ignition lock ZS switched second vehicle voltage VB2 the second supply line S2. As can also be seen from FIGS. 5 and 6, the outputs of the illustrated exemplary embodiments are each connected and attenuated individually in front of the common node KP by an RC element with ground GND, which comprises an ohmic resistor Rs11, Rs21 and a capacitor Cs11, Cs21 , Since a connection to a vehicle energy source B1, B2 in addition to the ohmic line resistance Ril, Ri2 also includes the line inductance Lil, Li2, can be determined by the RC elements due to the

Switching operations of the switching elements Svsl, Svs2 caused interference voltages on the phase voltages VS1.VS2 and on the reverse polarity protected supply voltage VP can be compensated, which could endanger optimal control of the switching elements Svsl, Svs2 otherwise. The dimensioning of the RC elements depends on the line inductances Lil, Li2 and the

String currents of the supply strings Sl, S2.

The characteristic diagram of FIG. 8 shows a characteristic diagram of voltages during a simulation of a normal operation of the multi-string supply unit 1A according to the invention for a vehicle control device 2 from FIG. 1 with the protective device 3B from FIG. 3. As can be seen from FIGS. 3 and 8, at the time 1, the vehicle voltage VB is applied, so that the first phase voltage VS1 is greater than the difference between reverse polarity protected supply voltage VP and the set hysteresis and the first switching element Svsl is closed. Since at time 1 the ignition lock ZS or the ignition lock switch is open, the second phase voltage VS2 is smaller than the difference between polarity protected supply voltage VP and the set hysteresis, so that the second switching element Svs2 remains open. Therefore, the first supply line Sl at time 1, the entire supply Ström IVP for the subsequent load RL and a subsequent control unit.

As a result, the first phase voltage VS1 is smaller than the vehicle voltage VB by the voltage drop V_Ril caused by the supply current IVP at the line resistance Ri of the first supply line S1. In addition, the reverse polarity protected supply voltage VP is smaller than the first phase voltage by the voltage drop V_Ril across the first switching element Svsl

VS1. The volume resistance of the first switching element Svsl in the illustrated embodiment has a value of about 10 mOhm and is therefore much smaller than the line resistance Ril of about 100 mOhm. The volume resistance of the first switching element Svsl is dependent on the size of the transistor used. As a result, the voltage drop V_Svsl across the switching element Svsl is also much smaller than the voltage drop V_Ril across the line resistance Ri, so that the line resistance Ri of the first supply line S1 and not the bridged first protection diode Dvsl is decisive for the level of the reverse polarity protected supply voltage VP. If the ignition lock ZS or the ignition switch ignition is closed at time 2, the condition applies at the beginning in the currentless second supply line S2 that the second line voltage VS2 corresponds to the vehicle voltage UB and is greater than the difference between reverse polarity protected supply voltage VP and the set hysteresis. Therefore, at time 2, the second switching element Svs2 in the second supply line S2 is closed. The result is a provision of the supply current IVP via two supply lines Sl, S2, wherein the line resistors Ril, Ri2 of the supply lines are largely responsible for the current distribution in the supply lines Sl, S2 and not the Verpolungsschutzele- elements of the protection device 3B. If, for example, a value of 10 mOhm and for the first line resistance Ril a value of 107 mOhm and for the second line resistance Ri2 a value of 127 ohms are assumed for the volume resistances of the switching elements Svsl, Svs2, then the first supply line S1 represents 54% of the supply current IVP ready and the second supply line S2 provides 46% of the supply current IVP. The characteristic curve diagram from FIG. 9 shows various signal profiles of the multi-line power supply unit 1A for a vehicle control device 2 from FIG. 1 with the protective device 3B from FIG. 4, the two vehicle voltages VB1, VB2 being applied to the two supply lines S1, S2. have different DC components and are each disturbed by a sinusoidal noise. The interference voltage can be generated for example by a vehicle generator. In the illustrated simulation, the first vehicle voltage VB1 has a DC voltage component of 13.5 V and a first interference voltage with an amplitude of 4 V and a frequency of 1 kHz. The second vehicle voltage VB2 has a DC component of 11.5 V and a second interference voltage with an amplitude of 4 V and a frequency of 1 kHz, the first interference voltage and the second interference voltage having a phase shift of 90 °.

As can also be seen from FIG. 9, at time 1 the first vehicle voltage VB1 is greater than the second vehicle voltage VB2 and the first line voltage VS1 is greater than the difference between the reverse polarity protected supply voltage VP and the hysteresis. This has the consequence that the first switching element Svsl is closed. As a result, the voltage drop VS1-VP across the first supply line Sl is very low and the power loss P_Svsl of the first switch element Svsl is extremely low despite the high current Ivsl of about 14 A in the first supply line Sl with about 2 W. The power loss of a comparable protective diode without a parallel switching element Svsl would be at the same conditions between 7 W and 11 W. At the same time at time 1, the second vehicle voltage VB2 is smaller than the difference between the reverse polarity protected supply voltage VP and the hysteresis. This has the consequence that the second switching element Svs2 is open. As a result, no current IVS2 flows in the second supply line S2 and a reverse voltage is applied to the first protection diode Dvs2 of the second supply line S2, which prevents a return feed from the first supply line Sl in the second supply line S2. Thus, the supply of the controller 2 takes place at time 1 exclusively via the first supply line Sl. As can be seen from FIG. 9, the phase voltages VS1, VS2 and the reverse polarity-protected supply voltage VP are close to each other at time 2, so that due to the determining resistive line resistances Ril, Ri2 of the supply lines S1, S2 a division of the load current IL onto the two supply lines Sl, S2 is coming. Due to this distribution of power, the power losses P_Svsl, P_Svs2 of the switching elements Svsl, Svs2 reduce considerably to a value of about 0.2 W. The voltage drop VS2-VP over the second supply line corresponds to the voltage drop VS1-VP over the first supply line Sl and is 50 mV approximately three times lower than the voltage drop VS1-VP across the first supply line S1 at time 1.

In summary, in embodiments of the multi-strand supply unit 1A, 1B, IC according to the invention even with dynamic voltage differences at the supply lines VS1, VS2 of the control unit no static feedback from a supply line Sl, S2 in the other supply line Sl, S2. Furthermore, dynamic regenerations are also energy-limited and are essentially limited to the contents of the capacitances Csl, Cs2, Cp of the RC filters. Furthermore, the power losses P_Svsl, P_Svs2 of the switching elements Svsl, Svs2 are low and less than

2.2 W. The voltage drops VS1-VP, VS2-VP over the supply lines are low despite the high currents IVS1, IVS2 in the supply lines Sl, S2 and the resulting high load current IL active in the two-phase reverse polarity protection.

The characteristic curve diagram from FIG. 10 shows various signal profiles of the multi-strand supply unit 1A for a vehicle control device 2 from FIG. 1 with the protective device 3B from FIG. 4, wherein the two vehicle voltages VB1, VB2 which are applied to the two supply lines S1, S2 have different DC voltage components exhibit and not through

Interference voltages are disturbed. In the illustrated simulation, the first vehicle voltage VB1 has a DC voltage component of 13.5 V and the second vehicle voltage VB2 has a DC component of 12.5 V. As can be further seen from FIG. 10, at time 1 the first vehicle voltage VB1 is greater than the second vehicle voltage VB2. This results in a supply current IVP, which is about two-thirds of the current IVS1 of the first supply line Sl (IVS1 »8.2 A) and one-third of the current IVS3 (IVS2» 3.5 A) of the second supply line S2 for an assumed supply current IVP or IL of 11.75 A. Here it can clearly be seen that the line resistances Ril, Ri2 of the supply lines S1, S2 are decisive for the current distribution of high-current control devices, since internal impedances of the control device 2 almost no longer play a role due to the power loss reduction. The advantage of embodiments of the multiple-line supply unit 1A, 1B, IC according to the invention is that in addition to the redundancy for signaling a supply error with secure assumption of driver control via an at least partially autonomous vehicle function, also a permanent power loss reduction in the protective device 3A, 3B, 3C, 3D is achieved due to the power distribution. The voltage drops VSl-Vp, VS2-Vp across the supply lines Sl, S2 are extremely low at 82 mV and 35 mV. Thus, despite the high supply current IVP or IL = 11.75 A, the power loss P_Svsl in the first switching element Svsl with 680 mW and the power loss P_Svs2 in the second switching element Svs2 with 120 mW extremely low. The characteristic graph of Fig. 8 has been chosen to show which states are to be expected in a conventional supply situation over longer times.

As can also be seen from FIGS. 1 to 6, in the illustrated exemplary embodiments of the protective device 3A, 3B, 3C, 3D, a respective field-effect transistor FET1, FET2 forms the first protective diode Dvsl, Dvs2 and the corresponding switching element Svsl, Svs2 in the two supply lines Sl, S2 off. In the illustrated embodiments, the field effect transistors FET1, FET2 are each designed as a P-channel power MOSFET.

As can also be seen from FIGS. 3 to 6, in the exemplary embodiments illustrated, the protective device 3B, 3C, 3D respectively has a second protective diode Dzsl, Dzs2 in the two supply lines S1, S2 in parallel with the first protective diode Dvsl, Dvs2 and the switching element Svsl, Svs2 , The second protection diodes Dzsl Dzs2 protect the switching elements Svsl, Svs2 and reduce a pulse load. tion of the switching elements Svsl, Svs2. As a result, the switching elements Svsl, Svs2 can be protected from an ISO pulse load which can generate voltages of more than 40 V via the switching elements Svsl, Svs3. The second protection diodes Dzsl, Dzs2 are in the illustrated embodiments as a suppressor diode (TSV) with a breakdown voltage in the range of 24 V to

40 V executed. If, for example, in a supply line S1, S1, for example, by switching a seat heating, a pane heater, etc., to a negative type ISO (7637) pulse of type 1 (-100 V with respect to ground GND, 2 ms, Ri = 10 Ω), At the first moment, in the case of a normal control device supply state, a polarity protected supply voltage VP having a value of approximately 12 V is present at the common node KP. This results in a corresponding peak strand voltage VS1, VS2 of approximately -100 V. This leads in the peak to a voltage drop VSvsl or (VS1-VP9, VSvs2 or (VS2-VP), respectively, over the corresponding switching element Svsl, Svs2 of approximately -112 V. The selection of a corresponding P-channel power MOSFET with a withstand voltage between source and drain of 100 V and more with a low on-resistance is very expensive and leads to high space requirements.The additional second protection diodes Dzsl, Dzs2 can be used significantly reduce the impulse loadings of the switching elements Svsl, Svs2, so that cheaper transistor types with voltage stabilization between source and drain of less than 40 V and with low on-resistance can be used The additional second protective diodes Dzsl, Dzs2 can be omitted if the MOSFETs used have a sufficient and specific periodic avalanche energy static polarity reversal security of the control unit 2 against

Voltages up to 20 V are thus ensured, as well as the active control of the negative pulse load.

As can also be seen from FIGS. 3 and 4, in the illustrated exemplary embodiments of the protective device 3B, the outputs of the two supply lines S1, S2 are connected in common to the common node KP via a third protective diode Dzp to ground GND, which has a positive pulse load two supply lines Sl, S2 reduced. In the exemplary embodiments of the protective device 3C, 3D shown in FIGS. 5 and 6, the outlets of the two supply lines S 1, S 2 are individually in front of the common Sannen node KP via a third protection diode Dzsll, Dzs21 connected to ground, which reduces a positive pulse load of the two supply strands Sl, S2. The third protection diode Dzp, Dzsll, Dzs21 serve to protect against positive ISO pulses including a load drop. If there is a positive impulse load in a supply line S1, S2, then impulses above 30 V are clamped or limited by the third protective diodes Dzp, Dzsll, Dzs21 at the common node KP. The breakdown voltage of the third protection diode Dzp, Dzsll, Dzs21 can be selected in the range between 30 V to 42 V. The third protection diodes Dzp, Dzsll, Dzs21 lead to cost-effective solutions with MOSFETS as switching elements Svsl, Svs2 and enable unbalanced clamping or limitation of negative supply pulses through the second protection diodes Dzsl, Dzs2 and positive supply pulses through the third protection diodes Dzp, Dzsll , Dzs21, whereby the size and Absorbtionsleistung the negative clip elements can be decoupled from those of the positive clip elements. Furthermore, the unidirectional bracing at the common node KP combines enhanced protection against reverse polarity in the event of a string breaker defect with the aim of triggering the string fuse before it comes to damage in the control unit 2.

As can be seen from FIG. 6, the passive filter 20 is in a particularly advantageous embodiment of the multi-strand supply unit IC as

Multi-strand T-filter 20C performed. Here, in each case a first filter inductor LT1, LT2 is looped into the two supply strings S1, S2 between the switching element Svsl, Svs2 and the common node KP. A common second filter inductor LT is connected between the common node KP and a filter output VZP. Through the filter coils LT, LT1, LT2, a filter capacitance CT and an output capacitance Cout, the filter 20C can be adapted to the following switching regulator 2.1 of the control unit 2 with a switching frequency between 400 kHz to 4000 kHz. In particular, the filter 20C has a buffer capacitor ΟμΟΤ, which is designed for example as a hybrid polymer ELKO with very small ESR. The buffer capacitor ΟμΟΤ is coupled via an ohmic limiting resistor ΡψΟΤ, which has a value between 0.1 to 1 ohms and limits a peak current, coupled to the common node KP. In addition, the buffer capacitor ΟμΟΤ connected via a coupling diode ϋμΟΤ with the filter output VZP. The coupling diode ϋμΟΤ ensured fast and low-impedance buffering of the input voltage of the switching converter in the event of a short-term voltage breakdown of the first vehicle voltage VB1 and / or the second vehicle voltage. The coupling diode ϋμΟΤ is preferably as Schottky

Diode executed.

The multi-strand T-filter 20C advantageously allows a direct coupling of the multi-strand supply unit IC to the switching regulator 2.1 of the control unit 2. The passive filter 20C attenuates disturbances of the electrical system, in particular high-frequency sinusoidal horns with a frequency of about 5 kHz to 20 kHz, suppresses the repercussions of the switching regulator 2.1 on the electrical system and ensures the supply of the control unit 2 in the event of voltage drops in the supply lines Sl, S2. In addition, the first filter inductances LT1, LT2 integrated into the supply lines S1, S2 result in a

Time delay in the structure of a regenerative current from the supply line

51 in the supply line S2 and vice versa. In addition, the detection of the reverse polarity protected supply voltage VP can be made after the inductive coupling, resulting in ohmic coil resistance RT1, RT2 additional hysteresis. If, in the illustrated exemplary embodiment, a short circuit to ground occurs in a supply line S1, S2, the monitoring of the line voltage VS1, VS2 against the reverse pole protected supply voltage VP at the common node KP and the limited opening speed of the switching elements Svsl, Svs2 can be achieved due to the limited switching speed Refreshments of energy stored in the buffer capacitor ΟμΟΤ not completely avoid, but compared to the embodiment shown in Fig. 2, the multi-strand supply unit 1B of FIG. 2 significantly improve. The hardware controller 12A, 12B, 12C or parts of the hardware controller

12A, 12B, 12C are turned "on" or "off" via an N_SL input to which a sleep mode control signal N_SL is applied. For detecting line interruptions or checking the quality of a supply line S1,

52, the control lines are supplied to the control signals STR1_CTL, STR2_CTL of the hardware control unit 10A, 10B, 10C. The supervising The unit 14A, 14B, 14C can thus briefly open the switching elements Svsl, SVs2. As a result, in the case of a line interruption in a supply line S1, S2, the line voltage VS1, VS2 drops below a predetermined value

Threshold. This information is used to detect faults in the redundant control unit supply with the aim of getting the driver back on time

To give control over the at least partially autonomous function or to get the attention of the driver in time.

Likewise, by these control lines and the control signals STR1_CTL, STR2_CTL at voltage differences between the vehicle voltages

VB1, VB2 of IV under a second review of the supply lines Sl, S2 only the corresponding switching element Svsl, Svs2 to be tested supply line Sl, S2 are closed and the switching elements Svsl, Svs2 the other supply strands Sl, S2 are opened. Then the reaction of the corresponding string voltage VS1, VS2 in the loaded supply line S1, S2 to be tested can be detected and evaluated. Since the supply current IVP concentrates on the supply line S1, S2 to be tested, it can be checked whether under load at the current-carrying supply line to be tested Sl, S2 there is still a sufficiently high phase voltage VS1, VS2 at the input.

If the controller 2 is in sleep mode, then the sleep mode control signal N_SL is at the low logic level, and the hardware controller 12A, 12B, 12C will then receive only a very low supply current IVP at the terminal VPJN, which is much smaller than 10 μΑ. Likewise, no appreciable current flows into the terminals VS1JN, VS2JN. This means that the current flowing into the terminals is also much smaller than 10 μΑ. In addition, the switching elements Svsl, Svs2 are in their "default state" in sleep mode, ie open The control device 1 itself is not active in sleep mode and only receives a small supply current from the common node KP, which is smaller than 100 μΑ Therefore, the voltage drop which the first protection diodes Dvsl, Dvs2 can cause is irrelevant If the control unit 2 is awakened, the sleep mode control signal N_SL changes to the high logic level and the hardware control unit 12A, 12B, 12C is activated. fourth. As can be further seen from FIGS. 6 and 7, the field effect transistors FET1, FET2, which are designed as P-channel power MOSFETs, conduct in the forward direction via bulk diodes Dsvl, Dsv2 between drain and source. The driving of these field-effect transistors FET1, FET2 is effected by a positive source gate

Voltage, which is equivalent to a connection of the respective gate via control lines of the drive signals Svsl_CTL, Svs2_CTL to ground. Since the field effect transistors FET1, FET2 usually a max. Allow source gate voltage of 20 V and to increase the switching speed, the source-gate voltages are each limited by a arranged in the hardware control unit IOC Zener diode ZD1_1, ZD2_1 to a value of 5.1 V, for example. In each case a source-gate leakage resistance Rl_9, R2_9 (for example 100 kOhm) is placed in parallel with this zener diode ZD1_1, ZD2_1 in order to be able to reliably block the associated switching element Svsl, Svs2 in sleep mode. So in sleep mode with continuous supply in the supply lines

Sl, S2 no current can flow through the Zener diodes ZD1_1, ZD2_1, the control lines of the drive signals Svsl_CTL, Svs2_CTL via transistors Tl_3, T2_3 by the sleep module control signal N_SL are switchable. Resistors Rl_6, R2_6 (eg 5.1 KOhm) are used to limit the current in the control lines of the drive signals Svsl_CTL, Svs2_CTL in the case of an active controller 2, which is a voltage VS11, VS21 before the first filter inductors LT1, LT2 and thus also at the terminals of the hardware control unit 10C in the range of 5V to 36V allows. Resistors Rl_7 (e.g.

23.7K ohms), RI_8 (e.g., 51.1K ohms), R2_7 (e.g., 23.7K ohms), R2_8 (e.g.

51.1 kOhms) form the base divider for NPN control transistors Tl_3, T2_3. The

Phase voltages VS1 VS2 are detected by the terminals VS1JN, VS2JN at the hardware control unit 10C and via switchable transistors Tl_ll, T2_ll to corresponding voltage dividers Rl_13 (eg 75 kOhms), Rl_14 (eg 8.25 kOhms) or R2_13 (eg 75 kOhms), R2_14 (eg 8.25 kohms). The divided signals VS1_ADC, VS2_ADC are sent to the computer unit

14C forwarded. PNP transistors Tl_ll, T2_ll are switchable to generate in the sleep mode no sense divider current from the line voltages VSl, VS2 to ground GND. Therefore, these transistors Tl_ll, T2_ll are switched by NPN control transistors Tl_10, T2_10 by means of the sleep mode control signal N_SL. The sleep mode control signal N_SL points in sleep mode a low logic level and in normal mode a high logic level. Since the voltage detection of the phase voltages VS1, VS2 takes place before the protective device 3D, the switching stages are protected against reverse polarity by signal diodes D1_10, D2_10 and resistors R1_12, R2_12 (eg.

40.2 kOhm) are used to limit the current. Residuals Rl_ll, R2_ll (eg

51.1 kOHm) serve as base-emitter leakage resistors. Resistors Rl_15, Rl_16 and R2_15, R2_16 (eg 23.7 kOhm, 51.1 kOhm and 23.7 kOhm, 51.1 kOhm, respectively) form a base voltage divider of the NPN control transistors Tl_10, T2_10.

The supply strands Sl, S2 are connected to one another in the passive filter via the first filter inductances LT1, LT2 and generate the reverse polarity-protected supply voltage VP at the common node KP. The polarity protected supply voltage VP is supplied to the hardware control unit IOC at the terminal VPJN. A positive supply voltage is supplied to comparators CM P_1, CMP_2 via a PNP switching transistor T12_l and a low pass filter R12_l, C12_l (eg 10 ohms, 10 i F) on corresponding positive supply pins. By a control transistor T12_2 and this switching transistor T12_l by the sleep mode control signal N_SL is controllable. Thus, in the sleep mode of the control unit, no current is taken from the permanently present string voltages VS1, VS2 for supplying the comparators CMP_1, CMP_2. A resistor R12_4 (e.g., 40.2 kohms) serves to limit the current in the drive path of the switching transistor T12_l. A resistor R12_3 (eg, 51.1 kohms) serves as a base-emitter leakage resistor of the transistor T12_l. Resistors R12_5, R12_6 (e.g., 23.7K ohms, 51.1K ohms) form one

Base divider of the NPN control transistor T12 2.

The reverse polarity protected supply voltage VP of the coupled supply strings Sl, S2 is applied via series resistors Rl_m, R2_m (eg 100 Ω) to minus inputs of the comparators CMP_1, CMP_2. The strand tensions

VS1, VS2 at the inputs of the supply strings S1, S2 are applied to plus inputs of the comparators CMP_1, CMP_2 via the terminals VS1J N, VS2J N and series resistors Rl_p, R2_p (eg 5.1 kOhm). To protect against dangerous positive or negative voltages, as well as against polarity reversal, the plus inputs of the comparators CMP_1, CMP_2 are each provided by a unidirectional nal Zener diode ZD1_10, ZD2_10, which, for example, enable a clamp voltage of 27 V. The choice of the clamping voltages of the Zener diodes ZD1_10, ZD2_20 should preferably be below the clamping voltages of the protective diodes Dzsll, Dzs21, Dzp, so that at high positive pulse load in the electrical system, the switching elements Svsl, Svs2 the supply strands Sl, S2 are forcibly opened and the coupling of the control unit 2 only is still done via the first and second protection diodes Dvsl, Dvs2, Dzsl, Dzs2 the two supply strands Sl, S2. This can reduce the risk in the load-dump case. "Open-collector outputs" of the comparators CMP_1, CMP_2 are via current limiting resistors Rl_3, R2_3 (eg

7.5 kOhm) PNP switching transistors Tl_l, T2_l supplied. These switching transistors Tl_l, T2_l are arranged so that they short-circuit in the drive the source-gate voltage of the field effect transistors FETl, FET2. As a result, the blocking of the field effect transistors FET1, FET2 can be forced and the supply lines S1, S2 can be converted into the polarity protected state.

The comparators CMP_1, CMP_2 used preferably have a "common mode range" which, independently of the positive supply voltage of the comparators CMP_1, CMP_2, can for example be 44 V above a voltage potential at the ground connection of the comparators.

The PNP switching transistors Tl_l, T2_l for blocking the field effect transistors FET1, FET2 in the supply lines S1, S2 can be activated in addition to the comparators CMP_1, CMP_2 by control signals STR1_CTL, STR2_CTL of the computer unit 14 with the aid of NPN control transistors Tl_2, T2_2, and thus a transfer of the Supply strings Sl, S2 in a reverse polarity protected operation on the first protection diodes Dvsl, Dvs2 force. Resistors Rl_2, R2_2 (eg 7.5 kOhm) are used to limit the current during control. Resistors Rl_4, Rl_5 and R2_4, R2_5 (eg 23.7 kOhm, 51.1 kOhm or 23.7 kOhm, 51.1 kOhm) serve as the base voltage divider of the NPN control transistors Tl_2, T2_2. A Zener diode ZD12_1 (eg, 5.1 V) forms an optional reference voltage VREF of, for example, 5.1 V, which consists of the supply voltage VP connected to the collector of the T12_1 via the sleep mode control signal N_SL with the aid of a series resistor R12_2 (eg = 7, 5 kOhm) is produced, with a capacitor C12_l being connected in parallel for filtering. By the reference voltage VREF and the optional resistor R12_Hy defines a reference current. This is supplied to a current mirror T12_3. The mirror currents I REF are coupled out via transistors T12_4, T12_5 and fed to the minus inputs of the comparators CMP_1, CMP_2. Together with the resistors Rl_m, R2_m an adjustable hysteresis of the comparators CMP_1, CMP_2 is formed.

If the sleep mode control signal N_SL and the control signals STR1_CTL, STR2_CTL each have the low logic level, then the hardware control unit IOC is inactive and there is no or only an irrelevant small power consumption in the μΑ range at the terminals VS1JN, VS2JN .

VS11JN, VS21JN, VPJN of the hardware control unit IOC. As a result, the field-effect transistors FET1, FET2 are switched off and the line voltages VS1, VS2 are protected against reverse polarity via the first protective diodes Dsvl, Dsv2 or the parallel unidirectional second protective diodes Dzsl, Dzs2 and forwarded to the passive filter 20C, with a return current of a supply line Sl, S2 in the other supply beach Sl, S2 is not possible.

Is in normal operation with a first strand voltage VS1 vonl4V, a second strand voltage VS2 of 14 V, a first line resistance Ril of 200 Ω, a second line resistance Ri2 of 200 mO and the sleep mode control signal N_SL to a high logic level and the An Control voltage STR1_CTL, STR2_CTL is changed to a low logic level, then the voltage at the minus input of the first comparator CMP_1 is lower than the line voltage VS1 at the plus input of the voltage drop between the first phase voltage VS1 and the reverse polarity protected supply voltage VP plus a first hysteresis first comparator CMP_1. Analogously, the voltage at the negative input of the second comparator CMP_2 is smaller than the line voltage VS2 at the plus input of the second comparator CMP_2 by the voltage drop between the first line voltage VS1 and the reverse polarity protected supply voltage VP plus a second hysteresis. As a result, the outputs of the two comparators CMP_1, CMP_2 are blocked. The PNP switching transistors Tl_l, T2_l for driving the field effect transistors FETl, FET2 are therefore also blocked. Since the sleep mode control signal N_SL in normal operation is at a high logic level, are the control transistors Tl_3, T2_3 conductive. Thus, the gates of the field effect transistors FET1, FET2 are grounded, causing them to become conductive. The previous voltage drops between the phase voltages VSl, VSl and the reverse polarity protected supply voltage VP, which are caused in the open state of the field effect transistors FET1, FET2 essentially by the first protection diodes Dvsl, Dvs2, are thus greatly reduced by the parallel conducting field effect transistors FET1, FET2.

In active operation, the line resistances Ril, Ri2 are responsible for the current distribution in the supply lines Sl, S2, provided that the vehicle voltages VB1, VB2 are equal.

Thus, in embodiments of the operating method according to the invention for a multi-strand supply unit at the inputs of the at least two supply lines Sl, S2 respectively a strand voltage VSl, VS2 and the common node KP a reverse polarity protected supply voltage VP detected and evaluated. Here, the switching elements Svsl, Svs2 in the at least two supply lines Sl, S2 are controlled in dependence on the evaluation via corresponding drive signals Svsl_CTL, Svs2_CTL.

In addition, the computer unit 14C can compare the individual phase voltages VS1, VS2 with each other and / or with the reverse polarity protected supply voltage VP and generate the drive signals Svsl_CTL, Svs2_CTL for the at least one switching element Svsl, Svs2 via a hardware control unit 12A, 12B, 12C as a function of the comparisons. Thus, the at least two supply lines Sl, S2 can be checked individually during operation as a function of predetermined conditions. To determine supply errors, the at least two supply lines S1, S2 at predetermined time intervals and / or when a voltage difference between the phase voltages VS1, VS2 exceeds a predetermined amount can be individually checked by the computer unit 14C. Without these checking functions, the string voltage S 1, S 2 of the functional supply string S 1, S 2 can also be connected to the input of the interrupted supply by the coupling at the common node KP and the conducting switching elements Svsl, Svs2. sorgungsstrangs Sl, S2 are pending and therefore can not be detected by the voltage control.

Thus, the computer unit 14C can in normal operation with the control signals STR1_CTL, STR2_CTL, which are set to a high logic level, the field effect transistors FET1, FET2 open, so that an interrupted strand supply can be detected. Thus, in a first check of the two supply lines Sl, S2, the computer unit 14C can open the at least one switching element Svsl, Svs2 of the supply line S1, S2 to be tested, and detect the reactions of the corresponding line voltage VS1, VS2 and the reverse polarity protected supply voltage VP at the common node KP and evaluate. In this case, a line interruption in the supply line S1, S2 to be checked can be detected if the corresponding line voltage VS1, VS2 is below a predetermined minimum limit value in the range from 0 to 6V when the switching element Svsl, Svs2 is open. This means, for example, that the first control signal STR1_CTL is set to the low logic level and the second control signal STR2_CTL is set to the high logic level in order to check the second supply line S2 for a line interruption. Since the second supply line S2 undergoes a voltage reduction by the now effective first protective diode Dvs2 or second protective diode Dzvs2, the supply current IVP concentrates on the first supply line S1. If, in this state, the first phase voltage VS1 is detected as the first voltage VS1_ADC and the second line voltage VS2 as the second voltage VS2_ADC, then the second voltage VS2_ADC approximately corresponds to the second vehicle voltage VB2 if the phase current Isv2 does not flow in the second supply line S2. The first voltage VS1_ADC corresponds to the first phase voltage VS1 at maximum load. A line interruption to the second supply line S2 can be detected if a significantly lower voltage than the expected second vehicle voltage VB2 is present at the input of the second supply line S2.

Subsequently, the first control signal STR1_CTL can be set to the high logic level and the second control signal STR2_CTL to the low logic level to check the first supply line Sl. The indicates, for example, that the supply current IVP concentrates on the second supply line S2, since the first supply line Sl undergoes a voltage reduction by the now effective first protection diode Dvsl or second protection diode Dzvsl. If, in this state, the first phase voltage VS1 is detected as the first voltage VS1_ADC and the second line voltage VS2 as the second voltage VS2_ADC, the first line voltage VS1_ADC approximately corresponds to the first vehicle voltage VB1 if the phase current Isvl does not flow in the first supply line S1. The second tension

VS2_ADC corresponds to the second phase voltage VS2 at maximum load. A line interruption to the first supply line Sl can be detected if the input of the first supply line Sl a significantly lower voltage than the expected first vehicle voltage VBL is applied.

By knowing idle voltage values of the vehicle voltages VB1, VB2 and the phase voltages VS1, VS2 of the supply lines S1, S2 at maximum load, the computer unit 14C can conclude the quality of the supply line S1, S2 and provide maintenance information. Alternatively, the vehicle voltages VB1, VB2 of the arithmetic unit 14C can also be provided via various communication paths (Ethernet, FlexRay, CAN, LIN) by central vehicle systems. In this case, the poor quality can be recognized by the fact that the calculated internal resistance exceeds a predetermined limit. The internal resistance may increase over the lifetime, for example due to corrosion at the contact points or be worse.

If the no-load voltage values of the vehicle voltages VB1, VB2 differ greatly, there is a permanent risk of back-feeding in the case of linked supply strings S1, S2 without effective first protection diodes Dsvl, Dsv2, provided both switching elements Svsl, Svs2 are conductively controlled. In order to prevent this effect, the phase voltages VS1, VS2 are detected at the terminals VS1JN, VS2JN of the hardware control unit IOC and applied to the plus inputs of the comparators CMP_1, CMP_2. At each of the negative inputs of the comparators CMP_1, CMP_2, the concatenation of the phase voltages VS1, VS2 is applied as polarity protected supply voltage VP. In the embodiment shown in FIG. 6, this chaining of the supply strands takes place Sl, S2 in the passive supply filter 20C. Thus, a first filter inductance LT1, LT2 is effective in each supply line, as a result of which the recovery current increase is also dynamically decelerated and the finite response time of the real comparators CMP_1, CMP_2 can advantageously be fully or partially compensated. If, for example, the line voltage VS2 and the reverse polarity-protected supply voltage VP + hysteresis is greater than the line voltage VS2 at the input of the second supply line or the voltage at the terminal VS2JN, then the output of the second comparator CMP_2 switches to ground and activates the PNP switching transistor T2_l, which Gate and source of the second field effect transistor FET2 connects and thus the second switching element Svs2 opens. As a result, the second supply line S2 is in a diode coupling, so that the node KP backwards can not deliver a permanent stream in the second supply line S2.

The computer unit 14C can then generate a warning message and output via an acoustic and / or optical output unit if a line interruption and / or a problem and / or a poor quality in at least one of the two supply lines Sl, S2 are detected. Additionally or alternatively, the computer unit 14C store the warning message and output at a later time via a diagnostic interface. As a result, the respective at least partially autonomous function can be returned to the driver or a rapid service can be triggered without there being an urgent need for it, since, due to the redundant two-line supply, no unwanted functional restriction initially occurs.

Claims

claims

1. multi-strand supply unit (1A, 1B, IC) for a vehicle control unit (2), with at least two supply lines (Sl, S2), each connected at the input with at least one vehicle voltage source (B, Bl, B2) and at the output in a common node (KP) are combined, and a protective device (3A, 3B, 3C, 3D), which in the at least two supply lines (Sl, S2) each comprise at least one first protective diode (Dvsl, Dvs2), which in the forward direction between the at least one vehicle voltage - Source (B, Bl, B2) and the node (KP) in the at least two

Supply lines (Sl, S2) is looped, characterized in that in the at least two supply lines (Sl, S2) in each case at least one switching element (Svsl, Svs2) is connected in parallel to the at least one protective diode (Dvsl, Dvs2), wherein an evaluation and control unit (10A, 10B, IOC) at the inputs of the at least two supply lines (Sl, S2) each a strand voltage (VS1, VS2) and the common node (KP) detects a polarity protected supply voltage (VP) and evaluates and the switching elements (Svsl , Svs2) in the at least two supply lines (Sl, S2) as a function of the evaluation via corresponding control signals (Svsl_CTL, Svs2_CTL) drives.

2. Multi-strand supply unit (1A, 1B, IC) according to claim 1, characterized in that the evaluation and control unit (10A, 10B, IOC) compares the individual phase voltages (VS1, VS2) with each other and / or with the reverse polarity protected supply voltage (VP) and in dependence on the comparisons via a hardware control unit (12A, 12B, 12C) generates the drive signals (Svsl_CTL, Svs2_CTL) for the at least one switching element (Svsl, Svs2). Multi-strand supply unit (1A, 1B, IC) according to claim 2, characterized in that the evaluation and control unit (10A, 10B, IOC) the at least one switching element (Svsl, Svs2) via the hardware control unit (12 A, 12 B, 12 C), when a difference between the corresponding phase voltage (VS1, VS2) and the reverse polarity protected supply voltage (VP) at the common node (KP) exceeds a predetermined first threshold value.

Multi-strand supply unit (1A, 1B, IC) according to claim 2 or 3, characterized in that the evaluation and control unit (10A, 10B, IOC) the at least one switching element (Svsl, Svs2) via the hardware control unit (12 A, 12 B , 12 C) generated control signals (Svsl_CTL, Svs2_CTL) opens when the difference between the corresponding phase voltage (VS1, VS2) and the polarity protected supply voltage (VP) at the common node (KP) falls below a predetermined second threshold.

Multi-strand supply unit (1A, 1B, IC) according to claim 4, characterized in that a difference between the first threshold and the second threshold via a variable resistor (Rhys) in the hardware control unit (12A, 12B, 12C) is adjustable.

Multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 5, characterized in that the evaluation and control unit (10A, 10B, IOC) comprises a computer unit (14A, 14B, 14C), which the at least two supply lines (Sl S2) is individually checked as a function of predetermined conditions, wherein the computer unit (14A, 14B, 14C) generates at least one control signal (STR1_CTL, STR2_CTL) for checking the at least two supply lines (S1, S2) and sends it to the hardware control unit (12A, 12B, 12C) which generates and outputs the corresponding drive signals (Svsl_CTL, Svs2_CTL) for the at least one switching element (Svsl, Svs2) in response to the at least one control signal (STR1_CTL, STR2_CTL). Multi-strand supply unit (1A, 1B, IC) according to claim 6, characterized in that the computer unit (14A, 14B, 14C) generates a warning message and / or makes a fault storage and outputs via an audible and / or optical output unit and / or via a diagnostic interface if the computer unit (14A, 14B, 14C) detects a line interruption and / or a problem and / or a poor quality in the at least two supply lines (S1, S2).

Multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 7, characterized in that in the at least two supply lines (Sl, S2) each have a field effect transistor (FETl, FET2), the at least one first protection diode (Dvsl, Dvs2) and the at least one switching element (Svsl, Svs2) is formed.

Multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 8, characterized in that at least one second protection diode (Dzsl, Dzs2) in the at least two supply lines (Sl, S2) respectively parallel to the at least one first protection diode (Dvsl, Dvs2 ) and to which at least one switching element (Svsl, Svs2) is arranged and is suitable for reducing a pulse load of the at least one switching element (Svsl, Svs2).

Multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 9, characterized in that the outputs of the at least two supply lines (Sl, S2) each individually before the common node (KP) or together at the common node (KP) via at least a third protection diode (Dzp, Dzsll, Dzs21) is connected to ground (GND) which is suitable for reducing a positive pulse load of the at least two supply strands (Sl, S2), the at least one third protection diode (Dzp, Dzsll, Dzs21) limits a negative voltage occurring at the common node (KP) to a predefinable value and, in the case of a faulty strand switch (Svsl, Svs2) triggers an electrical vehicle fuse in case of polarity reversal.

Multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 10, characterized in that the inputs of the at least two supply lines (Sl, S2) in each case by at least one RC element, which has an ohmic resistance (Rsl, Rs2) and a Capacitance (Csl, Cs2) is connected to ground (GND) and attenuated.

Multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 11, characterized in that the outputs of the at least two supply lines (Sl, S2) each individually before the common node (KP) or together at the common node (KP) by at least an RC element comprising an ohmic resistor (RP, Rsll, Rs21) and a capacitor (CP, Csll, Cs21) connected to ground (GND) and attenuated.

Multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 12, characterized in that the common node (KP) via a passive filter (20) with the control unit (2) is connectable.

Multi-strand supply unit (1A, 1B, IC) according to claim 13, characterized in that the passive filter (20) has an energy reserve (ΰμΰΤ), which is adapted to compensate for a brief voltage dip.

Multi-strand supply unit (1A, 1B, IC) according to claim 13 or 14, characterized in that the passive filter (20) as a multi-strand T-filter (20C) is executed, wherein in each case a first filter inductance (LTL, LT2) in the at least two Supply lines (Sl, S2) between the switching element (Svsl, Svs2) and the common node (KP) is looped in, and wherein a common second filter inductance (LT) between the common node (KP) and a filter output is looped.

16. Operating method for a multi-strand supply unit (1A, 1B, IC) according to one of claims 1 to 15, characterized in that at the inputs of the at least two supply lines (Sl, S2) in each case one strand voltage (VS1, VS2) and at the common node ( KP) a reverse polarity protected supply voltage (VP) are detected and evaluated, wherein the switching elements (Svsl, Svs2) in the at least two supply lines (Sl, S2) depending on the evaluation via corresponding drive signals (Svsl_CTL, Svs2_CTL) are controlled.

17. Operating method according to claim 16, characterized in that the individual phase voltages (VS1, VS2) are compared with each other and / or with the reverse polarity protected supply voltage (VP) and in dependence of the comparisons the drive signals (Svsl_CTL,

Svs2_CTL) for the at least one switching element (Svsl, Svs2) via a hardware control unit (12A, 12B, 12C) are generated.

18. Operating method according to claim 16 or 17, characterized in that the at least two supply strands (Sl, S2) are checked individually during operation as a function of predetermined conditions.

19 operating method according to claim 18, characterized in that the at least two supply lines (Sl, S2) at predetermined time intervals and / or when a voltage difference between the phase voltages (VS1, VS2) exceeds a predetermined amount are checked individually.

20. Operating method according to claim 18 or 19, characterized in that in a first check of the at least two supply lines (Sl, S2) the at least one switching element (Svsl, Svs2) of a supply line to be tested (Sl, S2) is opened, and the reactions the corresponding phase voltage (VS1, VS2) and the polarity protected supply voltage (VP) at the common node (KP) are detected and evaluated.

Operating method according to claim 20, characterized in that a line interruption in the supply line to be checked (Sl, S2) is detected when the corresponding phase voltage (VS1, VS2) with open switching element (Svsl, Svs2) is below a predetermined minimum limit. 22. Operating method according to one of claims 18 to 21, characterized in that in a second check of the at least two supply lines (Sl, S2) only the corresponding switching element (Svsl, Svs2) of the supply line to be checked (Sl, S2) is closed and the Switching elements (Svsl, Svs2) of the other supply strands (Sl, S2) are opened, wherein the reaction of the corresponding strand voltage (VS1, VS2) in the loaded state of the supply line to be tested (Sl, S2) is detected and evaluated.

Operating method according to claim 22, characterized in that a problem in the loaded supply line to be tested (S1, S2) is detected when the corresponding phase voltage (VS1, VS2) is at a closed switching element (Svsl, Svs2) below a predetermined load limit.

Operating method according to one of claims 18 to 23, characterized in that the individual phase voltages (VS1, VS2) are compared with each other and each with a vehicle voltage (UB1, UB2) of the connected vehicle voltage source (Bl, B2), wherein based on the comparison to a Size of an internal resistance (Ril, Ri2) of the corresponding supply line (Sl, S2) is closed.

25. Operating method according to one of claims 18 to 24, characterized in that generates a warning message and / or a fault storage and output via an acoustic and / or optical output unit and / or via a diagnostic interface when a line break and / or a problem and / or poor quality in the at least two supply lines (Sl, S2) is detected, the bad Quality is detected by the fact that the internal resistance (Ril, Ri2) exceeds a predetermined limit.