DE102008062203A1 - Electrical system for car, has diode that is controllable by monitoring unit such that energy flow directed from auxiliary energy memory to energy storage is interrupted during starting of engine or during operation of engine - Google Patents

Abstract

The system (1) has an electronic relay unit (9) arranged between electrical system sections (1.1, 1.2). The unit has an electronic diode (9.1), a monitoring unit (9.2) and a control and monitoring unit (9.3). The diode is controllable by the monitoring unit such that energy flow directed from an auxiliary energy memory (10) to an energy storage (4) is interrupted during starting of engine or during operation of engine as a function of transient total resistance of memory determined on basis of monitoring unit whose electrical connecting cables and contacts are automatically stoppable. An independent claim is also included for a method for operating an electrical system.

Description

The The invention relates to an electrical system for a vehicle according to the preamble of claim 1 and a Method for operating the electrical system according to the The preamble of claim 11.

at Modern vehicles can be when starting an internal combustion engine due to a high electrical output of a starter to a burglary the electrical voltage of an electrical system of the vehicle come resulting in impairment of the operation of various in the electrical system arranged electrical system leads. Especially in a vehicle with an automatic start-stop system, which, for example an automatic shutdown of the internal combustion engine during standstill phases of the vehicle, such. B. when stopping at a traffic light, the voltage drop can noticeable loss of comfort, for example by switching off a car radio. To solve this problem Various approaches are known from the prior art.

The DE 10200702947.6 discloses an electrical system of a motor vehicle and a method for operating the electrical system. The electrical system comprises an electric machine for starting an internal combustion engine, a first accumulator from which electrical energy can be supplied to at least the electric machine, a generator drivable at least by the internal combustion engine, with which at least the first accumulator can be charged, and at least one electrical consumer. An electrical machine and the first accumulator comprehensive first part of the electrical system is at least unipolar from the one or more electrical consumers comprehensive second part of the electrical system separable, wherein in the second part an auxiliary voltage source is provided which can be charged at least by the generator and from the electric Consumer is supplied.

Of the Invention is based on the object, a relation to the State of the art improved electrical system and one opposite the prior art improved method of operating this specify electrical wiring system.

Regarding of the electrical system, the invention by the in the claim 1 specified characteristics and in terms of the method by the achieved in claim 11 specified features.

advantageous Embodiments of the invention are state of the subclaims.

The Inventive electrical system for a vehicle includes a first electrical system section with an electrical Machine for starting an internal combustion engine, an energy storage for Supply of the electric machine, an electric generator, with the at least the energy storage is rechargeable and a second Vehicle electrical system section with at least one electrical consumer and an auxiliary power storage for supplying the electrical load. According to the invention between the first electrical system section and the second electrical system section an electronic relay unit is arranged, which at least one of at least one semiconductor element formed activatable electronic diode, a monitoring unit for monitoring the auxiliary energy storage and a control and monitoring unit for control and monitoring the relay unit, wherein the electronic diode by means of such the control and monitoring unit is controlled that one directed by the auxiliary energy storage to the energy storage Energy flow interruptible at least when starting the engine or during operation of the internal combustion engine Internal combustion engine as a function of a determined by the monitoring unit transient total resistance of auxiliary power storage, its electrical Connecting cables and contacts can be stopped automatically.

The one-sided decoupling in the form of a diode functionality of the second electrical system section from the first electrical system section allows during the starting of the internal combustion engine a redundant Supplying the electrical load with electrical energy from both energy stores, at the same time an energy flow interrupted by the second electrical system section in the first electrical system section is, so that a voltage dip in the second electrical system section and thus an impairment of the operation of the electrical Consumer is avoided. Also equalizing currents between the auxiliary energy storage and the energy storage are thus avoided resulting in an increased life of the auxiliary energy storage leads.

in the Unlike conventional switches and relays, the of semiconductor elements, formed diode preferably no wear on allowing an exchange after a certain number of switching operations is not required. Compared to conventional Diodes has the one or more semiconductor elements, in particular Power semiconductors with a high current carrying capacity, formed Diode continues to have the advantage that no diode forward voltage is present and thus a power loss of the diode is minimal. Also, due to the use of semiconductor elements, it is opposite Relay a delay-free start of the internal combustion engine possible, which further enhances comfort.

By the determination of the total transient resistance, which is made up of the sum of the transient individual resistances of the auxiliary energy store, its electrical connection lines and its electrical contacts results, is always an accurate prediction of the voltage dip on the side of the second electrical system section when starting the internal combustion engine possible, so that the internal combustion engine preferably only is then stopped when in the auxiliary energy storage sufficient energy to supply the electrical consumer during the Starting the internal combustion engine is stored.

Farther the relay unit is preferably designed as a module, so that minimizes signal delays and errors, for example caused by long or defective transmission lines be avoided.

In a particularly preferred embodiment of the invention the relay unit a between the auxiliary power storage and the electrical consumer arranged electronic relay, which so coupled with the control and monitoring unit is that a flow of energy from the auxiliary energy storage to the electrical consumer can be generated and controlled. Thus, the auxiliary power source as needed, d. H. especially when starting the internal combustion engine, switchable, so that the electrical load from the auxiliary voltage source is dinable.

Also the electronic relay is preferably one or more Semiconductor elements formed, which in turn a low-loss and fast, in particular delay-free connection of the auxiliary voltage source results.

at the arranged in the first electrical system section energy storage it is preferably an accumulator, wherein according to a profitable embodiment of the invention, a battery sensor is provided for monitoring the accumulator, the one Evaluation software includes.

Of the Auxiliary energy storage is in particular a second accumulator, which preferably a smaller electrical capacity than the Energy storage, since the auxiliary energy storage the consumer only for a short time, d. H. during startup of the internal combustion engine with energy. By the smaller one Capacity of the accumulator has this in an advantageous manner Way a small size and low weight and cost savings can still be achieved.

The Control and monitoring unit additionally includes Means for limiting a charging current of the auxiliary energy storage, especially in training as a battery. Through this limitation, which, for example, based on a pulse-width modulation or a additional converter takes place, it comes to a lesser Loss of heat in the auxiliary energy storage, what its life extended. In addition, there is the possibility to control the charging current in such a way that it rises like a ramp, so that voltage dips or electrical system vibrations can be avoided are.

alternative the auxiliary energy storage is a capacitor, in particular a double-layer capacitor. Such double layer capacitors are also known as supercapacitors known and distinguished over conventional Capacitors characterized by a very high energy density. Farther Kondenstoren stand out against accumulators a longer life and a short time for charging out.

alternative the auxiliary energy storage is a flywheel storage. Drawing flywheel storage systems dependent on an independent voltage from the state of charge, a long life and a very high energy density out. Furthermore, these memories have a very low internal resistance, whereby the voltage is largely constant even at high load remains.

Further is the electric generator coupled to the internal combustion engine, so that during operation of the internal combustion engine electric Energy for charging the energy storage and the auxiliary energy storage as well as to supply the electrical load can be generated.

alternative The generator can also on the side of the second electrical system section be arranged. During generator operation, the electronic diode can be permanently turned off, so too the first energy storage can be loaded. Advantageous in this Execution is the redundant supply of the electrical Consumer, if there is an interruption in the electronic Diode path would come. Likewise a defect would be recognized by the electronic diode, since no charge current in the first energy storage is more possible. The charging current can be monitored via the battery sensor, for example become.

In a particularly advantageous development of the invention, electrical energy can be generated from a braking process of the vehicle by means of the generator and fed into the electrical system, ie a so-called recuperation can be generated, which leads to a fuel saving. The electrical energy generated by the generator is in turn the energy storage, the auxiliary energy storage and / or the electrical Ver consumable.

at the inventive method for operating a electrical wiring system for a vehicle that has a first Electrical system section with an electric machine for starting a Internal combustion engine, an energy storage device for supplying the electrical Machine, an electric generator with which at least the energy store is charged is and comprising a second electrical system section with at least an electrical load and an auxiliary power storage to Supply of the electrical load according to the invention at least when starting the internal combustion engine one formed from at least one semiconductor element electronic diode such means of a control and monitoring unit controlled that one of the auxiliary energy storage to the energy storage directed energy flow interrupted or during the Operation of the internal combustion engine of the internal combustion engine in dependence from a determined by a monitoring unit transient total resistance of auxiliary power storage, its electrical Connecting cables and contacts will be stopped automatically. alternative The generator can also on the side of the second electrical system section be arranged.

Farther at least when starting the internal combustion engine by means of the control and monitoring unit an electronic relay such controlled, that a second energy flow from the auxiliary energy storage is generated and controlled to the electrical load.

embodiments The invention will be described in more detail below with reference to drawings explained.

there demonstrate:

1 schematically an electrical system with two electrical system sections,

2 schematically the electrical system according to 1 and a current flow during operation of an internal combustion engine, and

3 schematically the electrical system according to 1 and a current flow during starting of the internal combustion engine.

each other corresponding parts are in all figures with the same reference numerals Mistake.

In 1 is an electrical system 1 a vehicle, in particular a vehicle with an internal combustion engine and a so-called automatic start-stop, with a first electrical system section 1.1 and a second electrical system section 1.2 shown.

The first electrical system section 1.1 includes an electric machine 2 for starting the internal combustion engine and an electric generator 3 , which converts kinetic energy from the internal combustion engine and / or a braking process of the vehicle into electrical energy and into the electrical system 1 feeds.

Furthermore, the first electrical system section comprises 1.1 a designed as an accumulator energy storage 4 , which by means of the electrical energy of the generator 3 is charged and to supply the electric machine 2 is provided when starting the engine and an electrical load 5 , For example, an electric power steering.

For monitoring the accumulator designed as energy storage 4 is a battery sensor 4.1 provided, which includes an evaluation software for evaluating the detected electrical characteristics, such as a battery voltage or a battery current, and other characteristics, such as a battery temperature. By means of the recorded characteristic values and their evaluation, it is possible in particular to decide whether a current state of the energy store 4 allows a shutdown of the internal combustion engine at a stop.

The second electrical system section 1.2 includes two electrical consumers 6 . 7 , wherein the second electrical load 7 by means of a quiescent current switch 8th , in particular when the ignition is deactivated, from the second electrical system section 1.2 is electrically separable. At the second electrical load 7 For example, it could be a car radio.

As the electric machine 2 for starting the internal combustion engine both in a cold start and in a warm start after a stop by the automatic start-stop system, a large amount of energy from the energy storage 4 is needed between the first electrical system section 1.1 and the electrical system section 1.2 an electronic relay unit 9 arranged on the basis of which a voltage dip and thus an impairment of the operation, in particular switching off the electrical load 6 and 7 in the second electrical system section 1.2 is avoided.

For this purpose, the electronic relay unit 9 an electronic diode 9.1 on, which consists of one or more semiconductor elements 9.11 is formed. Furthermore, the electronic relay unit 9 a monitoring unit 9.2 for monitoring a in the second electrical system section 1.2 arranged as an accumulator trained auxiliary power source 10 and a control and monitoring unit 9.3 on which all functions of the electronic relay unit 9 controls.

To the voltage dip in the second electrical system section 1.2 to avoid when starting the engine controls the control and monitoring unit 9.3 the diode 9.1 For example, by means of a so-called charge pump, such that one of the auxiliary energy storage 10 to the energy store 4 directed energy flow is interrupted, so that by means of the electric machine 2 generated voltage dip in the first electrical system section 1.1 not on the second electrical system section 1.2 transfers.

At the same time, the control and monitoring unit controls 9.3 one between the auxiliary energy storage 10 and the electrical consumers 6 and 7 arranged electronic relay 9.4 which is also part of the electronic relay unit 9 is. This is the relay 9.4 so controlled that a in 3 detailed energy flow E2 from the auxiliary energy storage 10 to the electrical consumers 6 and 7 is generated and so that the electrical consumers 6 and 7 be supplied with electrical energy during starting of the internal combustion engine without voltage dip.

The electronic relay is also made of one or more semiconductor elements 9:41 and 9:42 formed, these being in the illustrated embodiment of the invention, in particular, two oppositely connected in series power semiconductors.

The control and monitoring unit 9.3 is preferably further connected to other control units of the vehicle, for example via a LIN interface, so that the control of the relay unit 9 additionally in dependence of other variables, such as a temperature of the internal combustion engine, is controllable.

One from the energy store 4 and / or the generator 3 in the second electrical system section 1.2 Directed energy flow E1, which in 2 is shown in more detail, is both during operation of the internal combustion engine by means of the diode 9.1 admitted both during operation of the internal combustion engine and when starting the internal combustion engine.

Thus, during startup, a redundant, in the 3 shown supply of the second electrical system section 1.2 possible, since this is always supplied by the memory with the higher electrical potential. This is also true for an empty or defective auxiliary energy storage 10 an electrical supply to consumers 6 and 7 possible, but the voltage in the second electrical system section 1.2 breaks.

In particular, a warm start of the internal combustion engine after an automatic stop at empty and / or defective auxiliary energy storage 10 to be avoided by means of the monitoring unit 9.2 a transient total resistance of the auxiliary energy storage 10 , determines its electrical leads and contacts, by means of which a very accurate prediction of a possible voltage dip when starting the internal combustion engine can be made. Is enough in the auxiliary energy storage 10 Existing energy for a safe supply of consumers 6 and 7 not or is the auxiliary power storage 10 defective, thus an automatic stop of the internal combustion engine can be prevented. The transient total resistance results from the sum of the transient individual resistances of the auxiliary energy storage 10 , its electrical connection lines and its electrical contacts.

According to 2 becomes the auxiliary power storage 10 during operation of the operation of the internal combustion engine on the basis of the energy storage 4 and / or the generator 3 in the second electrical system section 1.2 directed in current flow or energy flow E1 by means of the energy storage 4 and / or the generator 3 loaded. To load the auxiliary power storage 10 , controls the control and monitoring unit 9.3 the relay 9.4 ie the semiconducting elements forming these 9:41 and 9:42 such that an energy flow from the energy storage 4 and / or the generator 3 to the auxiliary power storage 10 is possible.

To the life of the auxiliary energy storage 10 to increase, instructs the control and monitoring unit 9.3 Means by which a charging current can be limited and controlled. The limitation is realized for example by means of a pulse-width modulation or a converter. The charging current is preferably controlled in such a way that it ramps up and thus voltage dips and electrical system oscillations are avoided.

In 3 is the electrical system 1 and the energy flow E2 during starting of the internal combustion engine.

Due to the forward direction of the diode 9.1 which to the second electrical system section 1.2 directed is the already described redundant supply of the auxiliary energy storage 10 during starting of the internal combustion engine due to the energy flow E1 from the first electrical system section 1.1 possible.

1

board network

1.1

first Board power supply section

1.2

second Board power supply section

2

electrical machine

3

generator

4

energy storage

4.1

battery sensor

5

consumer

6

consumer

7

consumer

8th

Quiescent current switch

9

relay unit

9.1

diode

9.11

Semiconductor element

9.2

monitoring unit

9.3

Tax- and monitoring unit

9.4

relay

9:41

Semiconductor element

9:42

Semiconductor element

10

Auxiliary energy storage

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10200702947 [0003]

Claims (21)

Electrical wiring system ( 1 ) for a vehicle, comprising a first electrical system section ( 1.1 ) with an electric machine ( 2 ) for starting an internal combustion engine, an energy store ( 4 ) for supplying the electric machine ( 2 ), an electric generator ( 3 ), with which at least the energy store ( 4 ) and comprising a second electrical system section ( 1.2 ) with at least one electrical consumer ( 6 . 7 ) and an auxiliary energy storage ( 10 ) for the supply of the electrical consumer ( 6 . 7 ), characterized in that between the first electrical system section ( 1.1 ) and the second electrical system section ( 1.2 ) an electronic relay unit ( 9 ), which at least one of at least one semiconductor element ( 9.11 ) formed electronic diode, a monitoring unit ( 9.2 ) for monitoring the auxiliary energy storage ( 10 ) and a control and monitoring unit ( 9.3 ) for controlling and monitoring the relay unit ( 9 ), wherein the electronic diode ( 9.1 ) by means of the control and monitoring unit ( 9.3 ) is controllable that one of the auxiliary energy storage ( 10 ) to the energy store ( 4 ) directed energy flow at least when starting the internal combustion engine is interrupted or during operation of the internal combustion engine, the internal combustion engine in dependence on a basis of the monitoring unit ( 9.2 ) determined transient total resistance of the auxiliary energy storage ( 10 ), whose electrical connection lines and contacts can be stopped automatically. Electrical wiring system ( 1 ) according to claim 1, characterized in that the relay unit ( 9 ) between the auxiliary energy storage ( 10 ) and the electrical consumer ( 6 . 7 ) arranged electronic relay ( 9.4 ), which in such a way with the control and monitoring unit ( 9.3 ) is coupled such that an energy flow (E2) can be generated and controlled from the auxiliary energy storage to the electrical consumer. Electrical wiring system ( 1 ) according to claim 2, characterized in that the electronic relay ( 9.4 ) of one or more semiconductor elements ( 9:41 . 9:42 ) is formed. Electrical wiring system ( 1 ) according to one of claims 1 to 3, characterized in that the energy store ( 4 ) is an accumulator. Electrical wiring system ( 1 ) according to claim 4, characterized in that a battery sensor ( 4.1 ) is provided for monitoring the accumulator, wherein the battery sensor ( 4.1 ) comprises evaluation software. Electrical wiring system ( 1 ) according to one of claims 1 to 5, characterized in that the auxiliary energy storage ( 10 ) a second accumulator, in particular with a smaller electrical capacity than the energy store ( 4 ) is. Electrical wiring system ( 1 ) according to one of claims 1 to 6, characterized in that the auxiliary energy storage ( 10 ) is a capacitor. Electrical wiring system ( 1 ) according to one of claims 1 to 7, characterized in that the control and monitoring unit ( 9.3 ) Means for limiting and controlling a charging current of the auxiliary energy storage ( 10 ). Electrical wiring system ( 1 ) according to one of claims 1 to 8, characterized in that the electrical generator ( 3 ) is coupled to the internal combustion engine. Electrical wiring system ( 1 ) according to one of claims 1 to 9, characterized in that by means of the generator ( 3 ) electrical energy generated from a braking operation of the vehicle and in the electrical system ( 1 ) can be fed. Method for operating an electrical vehicle electrical system ( 1 ) for a vehicle, comprising a first electrical system section ( 1.1 ) with an electric machine ( 2 ) for starting an internal combustion engine, an energy store ( 4 ) for supplying the electric machine ( 2 ), an electric generator ( 3 ), with which at least the energy store ( 4 ) and comprising a second electrical system section ( 1.2 ) with at least one electrical consumer ( 6 . 7 ) and an auxiliary energy storage ( 10 ) for the supply of the electrical consumer ( 6 . 7 ), characterized in that at least when the internal combustion engine is started, one of at least one semiconductor element ( 9.11 ) formed electronic diode ( 9.1 ) by means of a control and monitoring unit ( 9.3 ) that one of the auxiliary energy storage ( 10 ) to the energy store ( 4 ) directed energy flow is interrupted or during operation of the internal combustion engine of the internal combustion engine as a function of a by means of a monitoring unit ( 9.2 ) determined transient total resistance of the auxiliary energy storage ( 10 ), whose electrical leads and contacts are automatically stopped. A method according to claim 11, characterized in that at least when starting the internal combustion engine by means of the control and monitoring unit ( 9.3 ) an electronic relay ( 9.4 ) is controlled in such a way that a flow of energy (E2) from the auxiliary energy store to the electrical consumer ( 6 . 7 ) is generated and controlled. Method according to claim 11 or 12, characterized in that the electrical consumer ( 6 . 7 ) during operation of the internal combustion engine by means of the energy store ( 4 ) and / or the electric generator ( 3 ) is supplied. Method according to one of claims 11 to 13, characterized in that during operation of the internal combustion engine by means of the control and monitoring unit ( 9.3 ) an electronic relay ( 9.4 ) is controlled such that the auxiliary energy storage ( 10 ) by means of the generator ( 3 ) and / or the energy store ( 4 ) is charged electrically. A method according to claim 14, characterized in that a charging current by means of the control and monitoring unit ( 9.3 ) and / or limited by means of a pulse-width modulation or a converter. Method according to one of claims 11 to 15, characterized in that the energy store ( 4 ) by means of a battery sensor ( 4.1 ) and an evaluation software is monitored. Method according to one of claims 11 to 16, characterized in that by means of the generator ( 3 ) generates electrical energy from a braking process of the vehicle and in the electrical system ( 1 ) is fed. Electrical wiring system ( 1 ) according to claim 1, characterized in that the electronic relay unit ( 9 ) at least one activatable electronic diode ( 9.1 ), which in the deactivated state permanently allows the flow of current in both directions and simulates an ideal diode function in the activated state and thus allows the flow of current only in one direction and blocks in the other. Electrical wiring system ( 1 ) according to claim 1, characterized in that the generator ( 3 ) on the side of the second electrical system section ( 1.2 ) is arranged and thus represents a redundancy while driving. Electrical wiring system ( 1 ) according to claim 1 and 19, characterized in that the generator is designed as a converter, which receives the energy from another island electrical system, for example, from a high-voltage network in hybrid vehicles. Electrical wiring system ( 1 ) according to one of claims 1 to 6, characterized in that the auxiliary energy storage ( 10 ) is a flywheel storage.