DE102015101235A1 - Electric power supply system for a vehicle and method for operating an electric power supply system - Google Patents

Abstract

An electric power supply system (1) for a vehicle has a ring conductor (L) and at least two separating elements (T1-T4) which in a coupling state of the respective separating elements (T1-T4) each have two sections (A1-A4) of the ring conductor ( L) electrically couple with each other. Furthermore, the electrical energy supply system (1) has a load (V1-V3) which is directly electrically coupled to one of the sections (A1-A4), wherein the separating elements (T1-T4) are each designed to be controllable in pairs in a disconnected state of the respective ones Separating elements (T1-T4) to electrically decouple a section (A1-A4) of the ring conductor (L) enclosed by the respective separating elements (T1-T4) from the remaining ring conductor (L).

Description

The invention relates to an electrical power supply system for a vehicle. Furthermore, the invention relates to a method for operating an electric power supply system.

Modern vehicles use electrical components that require high availability. For example, mechanical components are increasingly being replaced by so-called x-by-wire systems. These are systems in which driver wishes and other functions are transmitted electrically and operated, for example, by means of an electrohydraulic system. These include, for example, electric gearboxes (gear-by-wire), electric steering systems (steer-by-wire) and brake systems (break-by-wire). In particular, in the electro-hydraulic brake or electric steering a constant power supply is necessary because the driver can not intervene directly.

The DE 10 2005 042 665 A1 describes an electrical vehicle electrical system comprising a first subnetwork with a power source and a second subnetwork with a safety-related electrical load, wherein between the first subnetwork and the second subnetwork a coupling element is arranged, which does not transfer electrical energy from the first to the second subnetwork in the opposite direction. Furthermore, an electric vehicle electrical system is described, comprising a first subnetwork, a second subnetwork and a security-relevant consumer, which is supplied redundantly from the first and second subnetworks with electrical power, wherein a separating device is provided between the subnetworks.

The object underlying the invention is to provide a power supply system and a corresponding method which makes a contribution to enable a reliable power supply of an electrical load.

The object is solved by the features of the independent claims. Advantageous embodiments are characterized in the subclaims.

According to a first aspect, the invention is characterized by an electric power supply system for a vehicle.

The electrical energy supply system has an annular conductor and at least two separating elements, which in each case electrically couple two sections of the annular conductor to one another in a coupling state of the respective separating elements. The electrical energy supply system further comprises a consumer which is directly electrically coupled to one of the sections, wherein the separating elements are each pairwise controllable, electrically decouple in a disconnected state of the respective separating elements enclosed by the respective separating elements section of the ring conductor of the remaining ring conductor ,

This has the advantage that a faulty section of the ring conductor, for example due to a short circuit, can be isolated from the rest of the power supply system. Advantageously, it is thus possible to prevent an overall failure of the electrical energy supply system in the event of a partial failure of the electrical energy supply system. For example, a faulty portion may also occur as a result of damage, for example due to an accident or a marten bite.

A direct electrical coupling of the consumer to one of the sections in this context means that an electrical energy flow for operation of the consumer passes through the consumer directly after passing through said section of the ring conductor. An electrical energy flow for the operation of the consumer thereby extends only optionally and indirectly via a further section of the ring conductor.

The ring conductor is an electrical conductor that forms at least one closed ring. In this case, the ring conductor may comprise, for example, two closed rings, such as an "8" shape, ie in the form of the number eight. A closed conductor contributes in particular to a reliability of the electrical power supply system, as in the case of interruption of the ring conductor continues to be an electrical power supply to the consumer is possible.

In an advantageous embodiment according to the first aspect, the consumer is a security-relevant consumer.

Advantageously, the electrical energy supply system allows a high reliability of the safety-relevant consumer. For example, the consumer is an electric steering system (so-called "steer-by-wire") or an electro-hydraulic brake system (so-called "break-by-wire").

In a further advantageous embodiment according to the first aspect, the consumer is redundantly electrically coupled to at least two sections of the ring conductor.

This contributes to a particularly high reliability of the safety-relevant consumer. A redundant electrical coupling of the consumer can be realized, for example, inexpensively in combination with a consumer switching.

In a further advantageous embodiment according to the first aspect, the separating elements are designed as controllable semiconductor power switches. For example, such a separating element can be switched as desired between the disconnected state and the coupling state.

In a further advantageous embodiment according to the first aspect, the separating elements are designed as electromechanical circuit breakers.

In a further advantageous embodiment according to the first aspect, the separating elements are designed as blasting devices.

In a further advantageous embodiment according to the first aspect, the ring conductor is designed as a busbar.

Advantageously, such a simple integration of the separating elements is made possible.

According to a second aspect, the invention is characterized by a method for operating the electric power supply system. An error characteristic is determined which is representative of a short in one of the sections. Depending on the fault characteristic value, a control signal is sent to two separators enclosing the respective section for electrical decoupling of the respective section from the remaining ring conductor.

This has the advantage that an insulation of the section is made possible, so that an operation of the electric power supply system can be continued. In particular, the separating elements are controlled simultaneously, so that an electrical decoupling of the section can be carried out selectively. In particular, a simple fuse or a unidirectional DC-DC converter are not sufficient in this context, but it is necessary to take account of overloads in a section by means of consumer and generator control related to the section. In this case, a distinction of the voltage level per section and their coupling. A fuse, however, has a limited reaction range, for example in a so-called creeping short circuit, which is below a reaction threshold of the fuse. Furthermore, a unidirectional voltage converter has the disadvantage that a flow direction is restricted. A self-adjusting power distribution in the ring conductor can also cause a bidirectional direction. In addition, a unidirectional DC-DC converter is uneconomical in terms of cost and efficiency.

The switched separating elements need not necessarily include a single section, but rather can be a plurality of successively coupled together portions of the ring conductor from the rest of the ring conductor by switching only two separating elements electrically decoupled.

Embodiments are explained in more detail below with reference to the schematic drawings.

Show it:

1 an electrical power system in a schematic representation and

2 a flowchart for operation of the electric power supply system according to 1 ,

An energy supply system 1 for a vehicle ( 1 ) has a first electrical energy source Q1 and a second electrical energy source Q2, which are electrically coupled to a ring conductor L, comprising a first section A1, a second section A2, a third section A3 and a fourth section A4. By way of example, the first energy source Q1 is connected to the fourth section A4, and the second energy source Q2 is connected to the second section A2. For example, the ring conductor L may be formed as a busbar. In this embodiment, the ring conductor L is formed in the form of a single closed ring. In other embodiments, the ring conductor L may comprise further rings, which are electrically coupled together.

The sections A1-A4 may also be referred to as segments of the ring conductor L, that is to say the sections A1-A4 differ in particular from a so-called path, that is to say a section of a non-closed electrical conductor.

The first electrical energy source Q1 is, for example, an electrical generator such as an alternator of the vehicle or an electric drive of the vehicle in generator mode. The second electrical energy source Q2 is, for example, an electrical energy store, such as a battery or a capacitor. The energy supply system 1 for the vehicle can also be referred to as electrical system. deviant of the embodiment, the electric power supply system 1 also comprise only a single electrical energy source or other electrical energy sources.

The electrical energy supply system 1 further comprises a first separator T1, a second separator T2, a third separator T3 and a fourth separator T4. In a normal operation of the vehicle, the separating elements T1-T4 are in a coupling state in which they respectively connect two sections A1-A4 of the ring conductor L electrically. In this case, for example, the first portion A1 of the ring conductor L is electrically connected by the first separator T1 to the fourth portion A4 of the ring conductor L and electrically connected by the second separator T2 with the second portion A2 of the ring conductor L.

The electrical energy supply system 1 comprises at least two sections A1-A4 and at least two separating elements T1-T4. In this case, a number of the sections A1-A4 or the separating elements T1-T4 is not limited to four. In particular, the number of sections A1-A4 is dependent on the number of separating elements T1-T4.

In this embodiment, the electric power supply system includes 1 a first power distributor B1, a second power distributor B2, a third power distributor B3, and a fourth power distributor B4. Each contact of the power distributor B1-B4 is assigned, for example, an electrical fuse and / or a switch. In this context, the power distributors B1-B4 may also be referred to as fuse boxes. In this embodiment, the first and second current distributors B1, B2 are connected to the first portion A1 of the ring conductor L for supplying electrical energy, and the third and fourth current distributors B3, B4 are connected to the third portion A3 of the ring conductor L. In other embodiments electrical energy supply system 1 for example, free of the power distributors B1-B4, or the electrical energy supply system 1 includes any number of power distributors B1-B4.

In this embodiment, the electric power supply system includes 1 a first consumer V1, a second consumer V2 and a third consumer V3. In other embodiments, the electrical power system comprises 1 any number of consumers. Notwithstanding the embodiment, the electric power supply system 1 include only a single consumer or other consumers.

The first consumer V1 is in particular a safety-relevant consumer, such as an electric steering system of the vehicle or an electric brake system of the vehicle. In other embodiments, the first consumer V1 is a security-critical consumer whose reliability against other consumers V2, V3 of the power system 1 is prioritized. For example, such a first consumer V1 is designed as a tachograph.

The second and third consumers V2, V3 are, for example, safety-critical consumers, such as, for example, a comfort system of the vehicle.

A first supply line Z1 connects the first current distributor B1 on the output side to a first input of the first consumer V1. A second supply line Z2 connects the fourth current distributor B4 on the output side to a second input of the first consumer V1. For example, the first consumer V1 in this context, a switch assigned, depending on the switching state, an electrical power supply of the first consumer V1 is controllable via the first supply line Z1 or via the second supply line Z2. The redundant electrical energy supply of the first consumer V1 serves, for example, as a fallback level in the event of an interruption of the electrical energy supply, for example due to a short circuit, a cable break or due to contact corrosion.

The separating elements T1-T4 are in each case controllably configured to change from the coupling state into a separating state, in each of which two sections A1-A4 adjoining the respective separating elements T1-T4, or the sections A1-A4 electrically coupled to each other by the separating elements T1-T4 , are electrically decoupled from each other. The separating elements T1-T4 are formed for this purpose, for example, as a semiconductor power switch. In other embodiments, the separating elements T1-T4 may be, for example, electromechanical power switches or pyrotechnic, for example in the form of explosive devices.

The separating elements T1-T4 are in particular designed to be pairwise controllable, in the disconnected state to electrically decouple a respective section A1-A4 from the remaining ring conductor L. For this purpose, the separating elements T1-T4 are signal-coupled, for example, to a control unit E, in whose data and program memory a program for operating the electric power supply system 1 which is described below with reference to the flowchart of 2 is explained.

The program is started in a step S1 in which, for example, variables are initialized.

In a step S3, an error characteristic value is determined, which is representative of a faulty section A1-A4, in particular for a short circuit in one of the sections A1-A4 of the ring conductor L. For example, the separation devices T1-T4 in this context, a sensor unit associated detects a current and / or voltage curve of the respective adjacent sections A1-A4, so that a short circuit can be detected. The program is continued in a step S5.

In the step S5, a control signal for transition from the coupling state to the disconnection state is sent to two of the dividing elements T1-T4 including the defective portion A1-A4. In particular, the respective separating elements T1-T4 are controlled in such a way that the switching takes place as promptly as possible, in particular simultaneously. Advantageously, by disconnecting the defective portion A1-A4, for example, a short circuit from the remaining electric power supply system 1 isolated. The short circuit can be erased, for example, without the entire electrical energy supply system 1 to be taken out of service. Rather, the electrical energy supply system 1 For example, be kept at least in a kind of emergency operation, so that, for example, a trip to a workshop or a secure holding the vehicle is made possible. The program will then be terminated.

For example, in the case of a detected short circuit in the first section A1, the first and second isolating elements T1, T2 are switched to the disconnected state, so that the first section A1 is electrically decoupled from the remaining ring conductor L. The first consumer V1 is then supplied with electrical energy via the second supply line Z2. The second consumer V2, however, is electrically decoupled from an electrical power supply.

For example, at a detected short circuit in both the second section A2 and the third section A3, the second and fourth separating elements T2, T4 are switched to the disconnected state so that the second and third sections A2, A3 are electrically decoupled from the remaining ring conductor L , The first consumer V1 is supplied with electrical energy via the first supply line Z1. The third consumer V3, however, is electrically decoupled from an electrical power supply.

For example, in the case of a detected short circuit in the second section A2, the second and third isolating elements T2, T3 are switched to the disconnected state, so that the second section A2 is electrically decoupled from the remaining ring conductor L. Advantageously, all consumers V1-V3 can continue to be supplied with electrical energy. Due to an electrical decoupling of the second energy source Q2 from the rest of the electrical power supply system 1 For example, a maximum power consumption of the consumers V2, V3 is limited.

LIST OF REFERENCE NUMBERS

1

Power system

L

ring conductor

T1-T4

separating element

A1-A4

section

V1-V3

consumer

Q1, Q2

energy

B1-B4

power distribution

Z1, Z2

feed

e

control unit

S1, S3

program steps

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102005042665 A1 [0003]

Claims (8)

Electric power supply system ( 1 ) for a vehicle with - a ring conductor (L), - at least two separating elements (T1-T4) which in a coupling state of the respective separating elements (T1-T4) each two sections (A1-A4) of the ring conductor (L) electrically couple with each other , and - a consumer (V1-V3), which is directly electrically coupled to one of the sections (A1-A4), wherein the separating elements (T1-T4) are each pairwise controllable in a disconnected state of the respective separating elements (T1-T4) to electrically decouple a portion (A1-A4) of the ring conductor (L) enclosed by the respective separating elements (T1-T4) from the remaining ring conductor (L). Electric power supply system ( 1 ) according to claim 1, wherein the consumer (V1) is a safety-relevant consumer. Electric power supply system ( 1 ) according to one of the preceding claims 1 or 2, in which the consumer (V1) is redundantly electrically coupled to at least two sections (A1-A4) of the ring conductor (L). Electric power supply system ( 1 ) according to one of the preceding claims 1 to 3, wherein the separating elements (T1-T4) are designed as controllable semiconductor power switches. Electric power supply system ( 1 ) according to one of the preceding claims 1 to 4, wherein the separating elements (T1-T4) are designed as electromechanical circuit breakers. Electric power supply system ( 1 ) according to one of the preceding claims 1 to 5, wherein the separating elements (T1-T4) are formed as explosive devices. Electric power supply system ( 1 ) according to one of the preceding claims 1 to 6, wherein the ring conductor (L) is designed as a busbar. Method for operating an electrical energy supply system ( 1 ) according to one of the preceding claims 1 to 7, in which - a fault characteristic value is determined which is representative of a short circuit in one of the sections (A1-A4), and - depending on the fault characteristic value, a control signal at two the respective section (A1-4) A4) enclosing separating elements (T1-T4) is sent to the electrical decoupling of the respective section (A1-A4) of the remaining ring conductor (L).

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