DE102021205855A1 - electrical system - Google Patents

Abstract

Vehicle electrical system with at least two vehicle electrical systems, with a capacitor matrix (43) and at least one consumer (14, 22, 34, 42) being provided in at least one of the vehicle electrical systems, with the capacitor matrix (43) having at least one capacitor and at least one intermediate circuit capacitance one of the at least one consumer (14, 22, 34, 42).

Description

The invention relates to an on-board network and a method for operating such an on-board network.

State of the art

In automotive use, an on-board network is to be understood as the entirety of all electrical components in a motor vehicle. This includes both electrical consumers and supply sources, such as batteries. A distinction is made between the on-board power supply and the on-board communication supply. Vehicle electrical systems can have different voltage levels. Thus, vehicle electrical systems with high-voltage and low-voltage vehicle electrical systems are known.

In known vehicle electrical systems, a low-voltage battery is regularly used for the low-voltage vehicle electrical system. This is done even on electric vehicles equipped with large high voltage battery packs. Also because of the aging effect and the temperature sensitivity, the low-voltage batteries, which are intended for safety-relevant applications, e.g. for automated driving, have to be replaced on average every two years. This leads to additional costs and reduces the reliability of the energy supply for safety-relevant consumers (SR consumers), such as the steering and the brakes.

Furthermore, it should be noted that due to the positioning of the low-voltage batteries along the long energy paths, a certain voltage drop and energy consumption can occur, which leads to a reduction in the buffering capacity of the low-voltage battery and in energy efficiency.

Some methods are already known in which the use of so-called supercapacitors increases the buffering capacity and covers the dynamic power peaks of a consumer.

From the pamphlet DE102005036210A1 a circuit arrangement for supplying energy to an electric power steering system is known, in which an additional memory is provided to increase the power output of the electric power steering system.

Some of the known methods each use a local memory in order to improve the functionality of a component. However, a central low-voltage battery is always required.

Disclosure of Invention

Against this background, a vehicle electrical system according to claim 1 and a method with the features of claim 8 are presented. Embodiments emerge from the dependent claims and the description.

The vehicle electrical system presented comprises at least two vehicle electrical systems, with a capacitor matrix and at least one consumer being provided in at least one of the vehicle electrical systems, the capacitor matrix comprising at least one capacitor and an intermediate circuit capacitance of at least one of the at least one consumer.

In one embodiment, at least one of the capacitors is designed as a double-layer capacitor. In a further embodiment, all of the capacitors in the capacitor matrix are in the form of double-layer capacitors. A double-layer capacitor (DLC), also known as an electrochemical double-layer capacitor (EDLC), comprises two opposing conductive layers separated by an insulating layer.

In yet another embodiment, at least one of the capacitors is in the form of a supercapacitor. In a further embodiment, all of the capacitors in the capacitor matrix are in the form of supercapacitors. Supercapacitors, also known as supercaps, are electrochemical capacitors and represent a further development of double-layer capacitors. Due to their high power density, they can be charged and discharged very quickly. Supercapacitors typically have no dielectric. Their capacitance values result from the sum of two storage principles, namely the static storage of electrical energy through charge separation in a double-layer capacitance and the electrochemical storage of electrical energy in a pseudo-capacitance.

An intermediate circuit is an electrical device that, as an energy store, electrically couples several electrical networks at an intermediate current and voltage level via converters. The intermediate circuit capacitance is a capacitance in the intermediate circuit of converters, the task of which is to couple several electrical networks to one another on a common voltage level.

The method presented, which uses the capacitor matrix as an energy store, enables power management for an on-board network, esp especially for an on-board power supply system, with scalable, distributed low-voltage storage systems, with low-voltage batteries being replaced and an intermediate circuit capacity being used.

In this way, disadvantages associated with a central low-voltage battery can be avoided. Findings from the zone topology, especially in electrically powered vehicles, are used. Zone topology relates to a distribution of functions to control units based on the optimum spatial installation location, instead of a distribution of functions to control units specified for this type of function, for example allocation of the activation of the left front low beam to a control unit on the left front instead of to a central body computer. Furthermore, low-voltage batteries are being replaced by decentralized supercapacitors in particular. Control methods used in this way serve to optimize the power management.

The process presented makes it possible to minimize a low-voltage battery or even do without it completely. This is achieved by transferring the energy flow from high-voltage batteries to the low-voltage vehicle electrical system via high-voltage/low-voltage converters and solving the reduced buffering capacity due to the lack of low-voltage batteries via a scalable supercapacitor matrix and predictive power management to control the individual supercapacitors becomes. The supercapacitor matrix can consist both of DLC modules and of the intermediate circuit capacitances that are present in the loads currently used that contain electrical machines. In this way, the intermediate circuit capacities of the non-safety-related consumers (QM consumers) can also be used for voltage stabilization.

In addition, the supercapacitor matrix can be set to any voltage via simple power electronics to cover the positive and negative power peaks.

• Durch verteilte Lokalisierung der Niedervolt-Superkondensatoren kann die Niedervolt-Batterie entfallen.

The advantages of the method presented are, at least in some of the versions:

• The low-voltage battery can be omitted due to the distributed localization of the low-voltage supercapacitors.

Distributed low-voltage supercapacitors can be placed close to respective components to avoid a long energy transfer path from the low-voltage battery and the high voltage drop along the path. At the same time, the service life of the wire harness can be increased.

Supercapacitors have a significantly longer service life than low-voltage lead-acid batteries. Therefore, no regular maintenance is required. They can theoretically be in an optimal position, e.g. B. deep into the vehicle.

Intermediate circuit capacitors can be integrated into the supercapacitor matrix and further decoupled from the consumers' electrical motors.

The intermediate circuit capacity of the QM consumers can be used for voltage stabilization.

Predictive charging or discharging as well as dynamic coordination of the stored energy of the individual supercapacitors including the intermediate circuit capacitance are possible.

An optimal selection of the supercapacitors used for peak performance can be made. Due to the high complexity of the vehicle electrical system behavior, Multi-Objective Evolutionary Algorithm (MOEA) or reinforcement learning can be used. This is a machine learning method. The aim is an adaptive control strategy for the capacitor matrix, since the many possible variants that can occur in vehicles are not known beforehand. The algorithms used can be improved step by step.

The service life of the wire harness can be increased because long transmission paths of high currents are avoided.

Due to the reduced dynamic power peaks, the service life of the high-voltage/low-voltage voltage converter can be increased and the demands on them reduced. In this way, costs can also be saved.

The supercapacitor matrix can be scalable.

A low-voltage battery can be omitted by using distributed capacities to cover peak power requirements.

Sensible positioning of the capacitances can reduce energy consumption and increase the service life of the cable harness.

The intermediate circuit capacity can be used for power management by decoupling motors.

• Superkondensatoren können auf einen höheren Wert als die Bordnetznennspannung vorgeladen werden. Ggf. können vorgeladene Kondensatoren als Energievorhalt für das Bordnetz abgetrennt und bei Bedarf zugeschaltet werden.
• Ein Kondensator kann vorab auf einen niedrigeren Wert als die Bordnetznennspannung entladen werden. Ggf. können vorgeladene Kondensatoren als Energiesenke für das Bordnetz abgetrennt und bei Bedarf zugeschaltet werden.

The state of charge of the distributed supercapacitors can be controlled by the integrated simple line electronics. The following applies to this:

• Supercapacitors can be pre-charged to a value higher than the nominal vehicle voltage. If necessary, pre-charged capacitors can be disconnected as energy reserve for the on-board network and switched on if necessary.
• A capacitor can be discharged in advance to a value lower than the nominal voltage of the vehicle electrical system. If necessary, pre-charged capacitors can be disconnected as an energy sink for the vehicle electrical system and switched on if necessary.

The distributed capacitances can be coordinated by a central power management system in a central control unit with optimization algorithms for automatically selecting the energy transfer paths from individual supercapacitors. The function must have an overview of the condition of the supercapacitors as well as the wiring harness. Depending on the peak power requirements, the respective supercapacitor can be switched on. The concept of "digital twin" can be used here. This is a simulation model of the system to be controlled, with parameters configured and optimized to exactly replicate a real implementation. With a digital twin simulation model, e.g. B. the behavior of a system with a specific control can be predicted by simulation.

Further advantages and refinements of the invention result from the description and the accompanying drawings.

It goes without saying that the features mentioned above and those still to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

character list

• 1 shows the replacement of a low-voltage battery with a supercapacitor matrix in two block diagrams.
• 2 shows supercapacitors with step-down converter and step-up converter in two block diagrams.
• 3 shows distributed supercapacitors in a zone architecture.
• 4 shows performance diagrams in three graphs.
• 5 shows an embodiment of the presented method in a flow chart.
• 6 FIG. 12 shows a control method in a graph.

Embodiments of the invention

The invention is shown schematically on the basis of embodiments in the drawings and is described in detail below with reference to the drawings.

1 shows on the left side a classic low-voltage vehicle electrical system of an electric vehicle, which is denoted by reference numeral 10 overall. On the left-hand side, the illustration also shows a DC-DC converter 12, a QM consumer 14, e.g 22, e.g. a steering system, and a central low-voltage battery 24.

The idea on which the method presented is based now provides for replacing the central low-voltage battery 24 with supercapacitors, as is shown on the right-hand side.

The right-hand side shows a low-voltage vehicle electrical system 30 with a DC-DC converter 32, a QM consumer 34, e.g. an engine cooling fan or a windshield wiper, with power electronics 38, a switch 39 and an electric motor 40 safety-relevant (SR) loads 42 and a supercapacitor matrix 43 with a first supercapacitor 44, a second supercapacitor 46 and a third supercapacitor 48. The first supercapacitor 44 is assigned a buck converter 50. A step-up converter 52 is assigned to the third supercapacitor 48 .

Provision is therefore made to replace the central low-voltage battery 24 with the supercapacitors 44, 46, 48 or a supercapacitor matrix 42. The supercapacitors 44, 46, 48 can be positioned decentrally, e.g. B. in the vicinity of components of the vehicle electrical system 30.

Because of the significantly longer service life and charging cycles of the supercapacitors 44, 46, 48 compared to the low-voltage battery 24, the supercapacitors 44, 46, 48 do not have to be replaced over the life of the vehicle. Therefore, theoretically, they can be set up in any position instead of an accessible position. Such distributed supercapacitors can replace the component DC link capacitors by specification. The totality of all distributed supercapacitors 44, 46, 48 is referred to as a supercapacitor matrix 42.

• Eine Kapazität zum Erfüllen der Pufferfähigkeit der Niedervolt-Batterie. Dafür kann ein Superkondensator verwendet werden. Mit der integrierten Leistungselektronik werden die Spannung und Ladezustände gesteuert.
• Eine Kapazität, die der Zwischenkreiskapazität eines DC/AC-Wandlers (Inverter) oder eines DC/DC-Wandlers (Konverter) in Komponenten wie Hochvolt/Niedervolt-Spannungswandler, EPS, Motorkühler entspricht. Solche Kapazitäten können nicht vollständig steuerbar gemacht werden, weil immer eine gewisse Grundkapazität zum Betrieb der Komponenten benötigt wird. Dieser Typ der Kapazität kann jedoch vom Verbraucher entkoppelt gesteuert werden. Im normalen Fall wird nur ein Teil einer solchen Kapazität für den Betrieb benötigt. Der restliche Teil kann die Spannungsstabilität fördern. So kann bspw. die Zwischenkreiskapazität der Scheibenwischer für den Fall, dass es nicht regnet, vollständig genutzt werden.

The supercapacitor matrix 42 has two types of capacitances:

• A capacity to meet the buffering capability of the low-voltage battery. A supercapacitor can be used for this. With the integrated power electronics, the voltage and charging status are controlled.
• A capacitance that corresponds to the intermediate circuit capacitance of a DC/AC converter (inverter) or a DC/DC converter (converter) in components such as high-voltage/low-voltage voltage converters, EPS, engine coolers. Such capacities cannot be made completely controllable because a certain basic capacity is always required to operate the components. However, this type of capacitance can be controlled independently from the consumer. In the normal case, only part of such a capacity is required for operation. The remaining part can promote tension stability. For example, the intermediate circuit capacity of the windscreen wipers can be fully used if it is not raining.

2 shows a supercapacitor 100 with a buck converter (TSS) on the left and a supercapacitor 120 with a boost converter (HSS) on the right.

Terminal T30 102, terminal T31104, a first switch S1106, a second switch S2 108, in this case a MOSFET, and an inductor 110 are additionally shown on the left-hand side. Terminal T30 122, terminal T31 124, a first switch S1 126, a second switch S2 128, in this case a MOSFET, and an inductor 130 are additionally shown on the right-hand side.

Note that the supercapacitor 100 with TSS is pre-discharged to a low voltage value by clocking switches S1 106 and S2 108 prior to predictive power regeneration or load dump. When power regeneration occurs, S1 106 is turned on and S2 108 is turned off to absorb the power. After the backfeed, S1 106 and S2 108 are clocked again to discharge the supercapacitor 100.

The HSS supercapacitor 120 is pre-charged to a higher voltage prior to predictive power consumption by clocking S1 126 and S2 128 . When the power peak occurs, S2 128 is turned on and S1 126 is turned off to deliver the power. After power is delivered, the supercapacitor 120 is recharged by clocking S1 126 and S2 128 .

3 shows distributed supercapacitors in a zone architecture. On the left-hand side, the illustration shows supercapacitor modules 150, nodes 152, a safety-relevant consumer 154 and another module 156.

On the right side of the 3 central performance management 170 is illustrated. This shows a predictor 172, a digital twin vehicle electrical system 174 and a module 176 for multi-objective optimization. This is an optimization method that aims to achieve several target values at the same time or a best compromise between the target values, e.g. B. best voltage stability with a long service life of components instead of ideal voltage stability without considering the service life. A first input signal 180 carries information about a predictive driving maneuver, a second input signal 182 carries information about voltage and/or current. An output signal 184 carries information about which supercapacitors are switched on or off and information about the power from high-voltage/low-voltage DC/DC and degradation or switching off of QM consumers. An internal signal 190 carries information on a predictive power peak. A second internal signal 192 carries information about state variables of the vehicle electrical system.

It should be noted that the supercapacitor matrix can be positioned in a distributed manner depending on specific topologies and power requirements. The size and number of supercapacitors can be scaled depending on different vehicles. Depending on the power requirement and the power currently available from the high-voltage/low-voltage voltage converter and supercapacitors, multi-lens optimization can be used to decide which supercapacitors should be switched on or whether QM consumers should be downgraded. A multi-objective evolutionary algorithm (MOEA) or reinforcement learning can be used due to the high complexity of the vehicle electrical system behavior.

• Superkondensatoren, die direkt an Bordnetz angeschlossen sind.
• Superkondensatoren mit integrierten Tiefsetzstellern (3 TSS).
• Superkondensatoren mit integrierten Hochsetzstellern (3 HSS).

Three types of circuits can be used to control the single supercapacitor:

• Supercapacitors that are connected directly to the on-board network.
• Supercapacitors with integrated step-down converters ( 3 TSS).
• Supercapacitors with integrated boost converters ( 3 HSS).

• Die direkt am Bordnetz angeschlossenen Superkondensatoren stellen die für den Betrieb der Bordnetzkomponenten benötigte Grundkapazität zur Glättung der Leistungsspitzen im hohen Frequenzbereich zur Verfügung.
• Superkondensatoren mit TSS sind für zu hohe Stromrückspeisung oder Load dump gedacht. Sie können vorab auf einem niedrigeren Spannungsniveau, z. B. bis zur minimalen Betriebsspannung des Bordnetzes, entladen werden. Der genaue Spannungszielwert kann durch ein selbstlernendes Optimierungsverfahren des zentralen Leistungsmanagements dynamisch eingestellt werden. Wenn das zentrale Leistungsmanagement eine kommende oder gerade laufende Stromrückspeisung prädiziert oder bemerkt oder wenn eine optimierte Aufsuche der Energiepfade vorliegt, kann der rückgespeiste Strom zu bestimmten Superkondensatoren geführt werden.
• Superkondensatoren mit HSS sind für die zu hohe Stromaufnahme gedacht. Sie können vorab auf einem höheren Spannungsniveau, z. B. bis zur maximalen Betriebsspannung des Bordnetzes, aufgeladen werden. Der genaue Spannungszielwert kann durch ein selbstlernendes Optimierungsverfahren des zentralen Leistungsmanagements dynamisch eingestellt werden. Wenn das zentrale Leistungsmanagement eine kommende oder gerade laufende Stromaufnahme prädiktiert oder bemerkt oder wenn eine optimierte Aufsuche der Energiepfade vorliegt, kann der benötigte Strom aus bestimmten Superkondensatoren entnommen werden.

The operating procedures are:

• The supercapacitors, which are connected directly to the vehicle electrical system, provide the basic capacity required for the operation of the vehicle electrical system components to smooth out the power peaks in the high frequency range.
• Supercapacitors with TSS are intended for excessive current feedback or load dump. They can be preloaded at a lower voltage level, e.g. B. to the minimum operating voltage of the vehicle electrical system, are discharged. The exact voltage target value can be set dynamically by a self-learning optimization process of the central power management. If the central power management predicts or notices an upcoming or ongoing current feedback or if there is an optimized search of the energy paths, the returned current can be routed to specific supercapacitors.
• Supercapacitors with HSS are intended for the excessive current consumption. You can advance at a higher voltage level, z. B. are charged up to the maximum operating voltage of the vehicle electrical system. The exact voltage target value can be set dynamically by a self-learning optimization process of the central power management. If the central power management predicts or notices an upcoming or current current consumption or if there is an optimized search for the energy paths, the required current can be taken from certain supercapacitors.

• Zielfunktionen für die Multizieleoptimierung:
  • immer Einhaltung der Spannungsgrenzen der sicherheitsrelevanten Verbraucher,
  • möglichst konstanter Strom aus Hochvolt/Niedervolt-Spannungswandler,
  • möglichst kleine Spannungsschwankung im Bordnetz, möglichst wenige Einflüsse auf Komfortverbraucher bei Leistungsspitzen,
  • möglichst geringe gleichmäßige Alterung des Kabelbaums, z. B. durch Minimierung der mittleren Quadratwurzel des Stroms, möglichst geringer Energieverbrauch im Kabelbaum. Dies kann auch die Alterung von Schmelzsicherungen betreffen.
• Eingangsgrößen für das Leistungsmanagement:
  • Digital Twin zur Bildung des gesamten Bordnetzes Kabelwiderstand, Zustand, d. h. Ladung, Spannung, Innenwiderstand, des einzelnen Superkondensators, Zwischenkreiskapazität, wenn diese nicht in der Superkondensator-Matrix integriert ist, aktuelle Spannung und Strom der SR-Verbraucher, aktuelle Spannung und Strom der QM-Verbraucher, verfügbare Leistung der Hochvolt/Niedervolt-Spannungswandler.
  • Prädiktiver Leistungsbedarf der SR-Verbraucher
• Stellgrößen für das Leistungsmanagement:
  • Ausgangsspannung/-strom der Hochvolt/Niedervolt-Spannungswandler,
  • Zu-/Abschaltung/Degradierung von QM-Verbrauchern, Spannungseinstellung/Zu-/Abschaltung der einzelnen Superkondensatoren,
  • Regelung des Stroms der Superkondensatoren.

Power management to coordinate the distributed supercapacitors can be done as follows:

• Objective functions for multi-objective optimization:
  • always compliance with the voltage limits of the safety-relevant consumers,
  • as constant as possible current from high-voltage/low-voltage converter,
  • the smallest possible voltage fluctuation in the on-board network, the fewest possible influences on comfort consumers at power peaks,
  • the least possible uniform aging of the wiring harness, e.g. B. by minimizing the mean square root of the current, the lowest possible energy consumption in the cable harness. This can also affect the aging of fuses.
• Input variables for performance management:
  • Digital twin to form the entire on-board network Cable resistance, condition, ie charge, voltage, internal resistance, of the individual supercapacitors, intermediate circuit capacitance if this is not integrated in the supercapacitor matrix, current voltage and current of the SR consumers, current voltage and current of the QM -Consumer, available power of the high-voltage/low-voltage converter.
  • Predictive power demand of the SR consumers
• Variables for performance management:
  • Output voltage/current of the high-voltage/low-voltage voltage converters,
  • Connection/disconnection/degradation of QM consumers, voltage setting/connection/deactivation of the individual supercapacitors,
  • Controlling the current of the supercapacitors.

4 shows performance diagrams in three graphs. In a first graph 200, on the abscissa 202 of which the time t is plotted and on the ordinate 204 of which the power P is plotted, a first curve 206 shows the profile of P_Last and a second curve 208 shows the profile of P_DCDC. P_Last is the power peak of the consumers. P_DCDC is the performance of the high-voltage/low-voltage voltage converters in the time domain. Due to the regulation time of the high-voltage/low-voltage voltage converter, a highly dynamic power peak cannot be completely covered.

In a second graph 220, on the abscissa 222 of which the time t is plotted and on the ordinate 224 of which the power P is plotted, a curve 226 shows the course of a power difference between P_Last and P_DCDC in the time domain.

In a third graph 240, on the abscissa 242 of which the frequency f is plotted and on the ordinate 244 of which the power P is plotted, a first curve 246 shows a power requirement in the low frequency range and a second curve 248 shows a power difference between P_Last and P_DCDC in the high frequency range. The remaining power requirement in the low frequency range is covered directly by the supercapacitors and decoupled intermediate circuit capacitances connected to the vehicle electrical system. The remaining power requirement in the higher frequency range is covered by supercapacitors with step-up converters through power prediction and pre-charging.

5 shows a flowchart for controlling the supercapacitor matrix and the QM consumers to cover the predictive power requirements or the power recovery. In a first step 300, the power output of the DC-DC converters is adjusted (DCDC), charging the supercapacitors with HSS and discharging the supercapacitors with TSS. In a next step 302, the power requirement for the next step is predicted. A check is then made in step 304 as to whether the predictive performance is in the optimal operating range of the DCDC. If this is the case, there is a jump back (arrow 306) to step 300. If this is not the case, the method is split (arrow 308).

In a step 310 it is checked whether a predictive power feedback is taking place. If this is the case, it is checked (arrow 312) in a step 314 whether the predictive power feedback is <= the maximum power consumption of the supercapacitors with TSS. If this is the case, then (arrow 316) in a step 318 the required supercapacitors with TSS are selected. In a step 320, the required supercapacitors are then switched on with TSS. Then there is a jump (arrow 322) to step 302.

If it is determined in step 314 that it is not the case that the predictive power feedback <= the maximum power consumption of the supercapacitors with TSS, it is checked (arrow 324) in a step 326 whether the predictive power feedback <= the power consumption of the supercapacitors with TSS and is the QM consumer. If this is the case, then in step 330 the degree of degradation of the QM consumers is calculated (arrow 328). Then, in step 332, the required supercapacitors with TSS are switched on and then in a step 334 the QM loads are switched on. Then (arrow 336) there is a jump to step 302.

If it is determined in step 326 that it is not the case that the predictive power feedback <= the power consumption of the supercapacitors with TSS and the QM consumer, it is checked (arrow 338) in a step 340 whether the predictive power feedback <= the power consumption of the Supercapacitors with TSS plus the QM load plus the power output is the DCDC. If this is the case, then in step 344 the reduction in the power output of the DCDC is calculated (arrow 342). Then, in a step 346, the required supercapacitors are switched on with TSS. In a step 348, the QM consumers are switched on. Then, in a step 350, the DCDC power output is reduced. A jump to step 302 follows (arrow 352).

In a step 360 it is checked whether there is a predictive power demand. If this is the case, a check is made (arrow 362) in a step 364 as to whether the predicted power requirement is <= the maximum power reserve of the supercapacitors with HSS. If this is the case, then in a step 368 the required supercapacitors with HSS are selected (arrow 366). Then, in a step 370, the required supercapacitors with HSS are switched on. Then (arrow 372) there is a jump to step 302.

If the check in step 364 shows that the predicted power requirement is <= the maximum power reserve of the supercapacitors with HSS, a check is carried out (arrow 374) in step 376 to determine whether the predicted power requirements <= the power reserve of the supercapacitor Matrix plus DCDC are. If this is the case, then in step 380 the required DCDC power output is calculated (arrow 378). Then, in a step 382, the required supercapacitors with HSS are switched on. This is followed in a step 384 by an increase in the DCDC power output. This is followed (arrow 386) by a jump to step 302.

If the check in step 376, which does not apply, shows that the predicted power requirements <= the power reserve of the supercapacitor matrix plus DCDC, a check is carried out (arrow 388) in step 390 to determine whether the predicted power requirements <= the power reserve of the supercapacitor -Matrix plus the DCDC plus the quality consumer are. If this is the case, then in a step 394 the degree of degradation of the QM consumers is calculated (arrow 392). Then, in a step 396, the required supercapacitors with HSS are switched on. This is followed in a step 398 by increasing the DCDC power output. Then, in a step 400, QM consumers are degraded or switched off. There is then a jump (arrow 402) to step 302.

6 FIG. 4 shows in a graph 450, on the abscissa 452 of which the predictive performance is plotted and on whose ordinate 454 the type of control method is plotted, different control methods depending on the levels of the predictive power.

A first control method 460 includes the degradation of the QM consumers. A second control method 462 relates to high-end DCDC regulation. A third control method 464 includes turning on the supercapacitors with HSS. A fourth control method 466 relates to turning on the supercapacitors with TSS. A fifth control method 468 includes engaging QM consumers. A sixth control method 470 relates to high-end DCDC regulation.

The method presented can be used, for example, in connection with application scenarios for on-board power supply systems with zone/ring topologies, with consumers installed distributed in the vehicle.

• Zonensteuergeräte,
• Fahrzeugsteuerung,
• Powernet Guardian (PNG), ein Haupttrennschalter mit integriertem elektronischen Leistungsverteiler und Bordnetzdiagnosefunktion, elektronische Leistungsverteiler (ePDU),
• Body-Computer.

The following components could, for example, integrate such a function:

• zone controllers,
• vehicle control,
• Powernet Guardian (PNG), a main circuit breaker with integrated electronic power divider and vehicle electrical system diagnostics function, electronic power divider (ePDU),
• body computer.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely 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 102005036210 A1 [0006]

Claims (10)

Vehicle electrical system with at least two vehicle electrical systems, with a capacitor matrix (43) and at least one consumer (14, 22, 34, 42) being provided in at least one of the vehicle electrical systems, with the capacitor matrix (43) having at least one capacitor and at least one intermediate circuit capacitance one of the at least one consumer (14, 22, 34, 42). on-board network claim 1 , In which at least one capacitor is designed as a double-layer capacitor. on-board network claim 1 , wherein at least one capacitor is designed as a supercapacitor (44, 46, 48, 100, 120). On-board network according to one of Claims 1 until 3 , In which the at least one sub-network, which has the capacitor matrix (43), is designed as a low-voltage sub-network. On-board network according to one of Claims 1 until 4 , in which the capacitor matrix (43) is assigned a step-up converter (52). On-board network according to one of Claims 1 until 5 , in which the capacitor matrix (43) is associated with a step-down converter (50). On-board network according to one of Claims 1 until 6 , in which the capacitor matrix (43) comprises a plurality of capacitors which are arranged in a decentralized manner. Method for operating a vehicle electrical system (10) according to one of Claims 1 until 7 In which the capacitor matrix (43) is used as an energy store for at least one of the sub-board networks that has the capacitor matrix (43). procedure after claim 8 , in which performance management is carried out. procedure after claim 8 or 9 , in which an inflow of energy from a high-voltage sub-board network into a low-voltage sub-board network that has the capacitor matrix (43) takes place.

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