WO2014191135A1

WO2014191135A1 - Module separation in battery systems in the event of accidents

Info

Publication number: WO2014191135A1
Application number: PCT/EP2014/057646
Authority: WO
Inventors: Stephan Woeber
Original assignee: Robert Bosch Gmbh
Priority date: 2013-05-27
Filing date: 2014-04-15
Publication date: 2014-12-04
Also published as: DE102013209835A1

Abstract

The invention relates to a battery system (2) for a vehicle, comprising at least two battery modules (4) connected in series. The battery system is characterised in that said system (2) also comprises a separator element (6) which is connected in series between the battery modules (4), is designed to provide a substantially loss-free conductive connection during the normal operation of the vehicle, and which is designed in such a way that, in the event of an accident, the conductive connection between the battery modules (4) can be broken, in particular irreversibly broken.

Description

Module separation in battery systems in the event of accidents

The present invention relates to electric or hybrid vehicle technology.

In particular, the present invention relates to battery system technology for electric and hybrid vehicles. Further particularly, the present invention relates to a battery system for a vehicle and a vehicle, in particular electric or hybrid vehicle.

State of the art

Battery systems for electric or hybrid vehicles, thus their

Traction batteries are regularly built with a high system voltage in order to realize the required drive power with the lowest possible currents and thus small cable cross-sections or ohmic losses. These battery systems are often in or directly below the

Passenger compartment or housed in the engine compartment. In the event of accidents, occupants of the vehicle, for example the driver, as well as rescue personnel may be exposed to the risk of high DC voltages. Furthermore, a high voltage may lead to arcing, which is usually not self-extinguishing. The development of heat can result in subsequent burn marks or the evaporation of large quantities of metallic material. Particularly relevant is the comparatively large stored amount of energy in a battery system for electric or hybrid vehicles.

In an accident scenario, it may thus cause uncertainty in extinguishing or

Salvage forces come, whereby these may be restrained in their use, in particular with regard to the use of extinguishing water and / or heavy salvage equipment, and in particular the principle of intrinsic safety before salvage follow. Disclosure of the invention

One aspect of the present invention may be seen therein, an improved battery system for vehicles, in particular electric or

To provide hybrid vehicles.

Accordingly, a battery system for a vehicle and a vehicle, in particular electric or hybrid vehicle according to the independent

Claims are displayed. Preferred embodiments will be apparent from the dependent claims.

A battery system for the drive (traction battery) of electric or

Hybrid vehicles can be used as a large single module e.g. be housed in the sandwich floor or rear of the vehicle, or consisting of several individual modules distributed in the vehicle. It is regularly well protected for normal operation. Battery management systems are used which, on the one hand, monitor single cells for overcharging during charging or recuperation, e.g. by over-voltage monitoring,

on the other hand allow temperature monitoring of the modules, so as to prevent thermal overload of the cells in normal operation. Furthermore, the single cell monitoring may be monitoring for a

Provide undervoltage, thus preventing a deep discharge, which may possibly lead to internal short circuits and thus to overheating of the battery cells. An insulation test against the

The vehicle body may continue to detect insulation failure of lines, in which case the vehicle may be electronically fused for re-commissioning.

Furthermore, fuses are regularly provided within a battery system, which short-circuit on the battery cables or in the

Secure the electrical inverter. In addition, in known

Battery systems Battery contactors, electromagnetic switches for

Hochstromanwendungen provided, which are opened in the idle state of the vehicle or in the fault state or in an accident and thereby disconnect the battery lines in the vehicle. However, the aforementioned safety devices usually do not interfere with the destruction of the battery housing, for example in the case of an accident or when vehicles are sinking into waters. Thus, by the destruction of the insulating housing or by the penetration of metallic body parts or the unfolding of battery modules shorts between the cells and connecting lines arise or connecting lines are exposed at high voltages from the insulation. On the other hand, may be brought about by the penetration of water into battery modules, a conductive connection of the cells. These scenarios can lead to a short circuit with high voltages or arcing.

In terms of design, battery systems for electric or hybrid vehicles, thus their traction batteries, are designed as a plurality of battery modules, which are connected in series. The individual battery modules are self-contained or (hermetically) sealed housing, which in an undamaged state provide protection against contact with live parts and also against the ingress of water or extinguishing water. Such

Battery module is internally constructed mostly as a plurality of individual battery cells, for example, six cells in series, and has a module voltage of, for example, full charge of e.g. 24V up.

A plurality of such battery modules are subsequently also connected in series to form a battery system. For example, twelve such battery modules can be connected in series and thus achieve a total voltage of about 300 V. The wiring of the individual battery modules with each other is done regularly by external conductor elements connected to terminal terminals of the individual battery modules, for example, properly screwed. These conductor elements can also be protected with respect to contact and liquid.

Since the voltage of a single battery module, for example, 24 V substantially equal to the voltage, as for example in

Resistant starter batteries are used in trucks, salvagers are familiar and skilled in dealing with such voltages. Only the series connection of a plurality of battery modules, which only results in a comparatively high voltage of, for example, 300 V, represents an increased and unfamiliar hazard potential.

According to the invention it is now proposed that the series circuit of

Batteriemodule suitable break up, so that only more individual

Battery module voltages are present in the vehicle.

According to the invention, in particular between the individual

Battery modules and from these for connection to the vehicle

Separating elements provided which separate the serial connection of the battery modules such that only more the individual voltages of

Battery modules are present in the vehicle. Thus, between the

Battery modules provided separation elements that trigger in case of accidents, reliably prevent the flow of electricity and thus the series connection of

Interrupt battery modules. By introducing separating elements, which in particular trigger only in the event of serious accidents, the voltage of the battery system is thus reduced to the level of the individual battery modules, which only results in a low voltage which is harmless for contact or arcing.

The effected triggering of the separating elements is preferably made visible by a display device to the outside, so that deletion or recovery forces can visually assure that the separating elements have actually triggered and thus prevail in the interior of the vehicle only more harmless voltage conditions. Such a visualization increases the objective safety of the occupants of a vehicle or the subjective safety of the extinguishing and recovery forces. Thus it can be read from outside the vehicle, whether the safety device has triggered and the vehicle is thus substantially free of stress.

Due to the accident scenarios in which such a separating element triggers regularly, can be provided in particular that the separating elements only have to trigger once or can, thus trigger irreversible. In this way, such a separating element can have a construction which is particularly suitable for the single triggering and can therefore be constructed in a particularly simple manner be. This makes it possible in particular a comparatively lower

Internal resistance of the separator and thus realize low line losses at a relatively large switching path. Such a construction may also be suitable for extinguishing an arc or for the preferred waterproof design of a separating element. The

Separating elements can be triggered in the vehicle via their own control devices or a separate control unit. Alternatively, e.g. to

Cost reduction, the triggering device for airbags or the coupled accident detection can be used to make, for example, via or parallel to the airbag control unit, the release of the separating elements.

The same control unit can also be used subsequently to provide a display element at a suitable point in the vehicle, for example in the windshield area next to the A-pillar or in the side window area of the driver, which is a safe state for extinguishing and salvaging forces or generally to the outside , thus signaled a battery system with separate battery modules.

According to the invention, the separating elements are either in the

Conductor elements or the connecting lines or their

Cable clamping devices arranged between different battery modules or are alternatively installed as an integral part of a battery module in this or in their fittings.

The disconnectors can be triggered by their own control unit, via the battery control unit (BCU) or the airbag control unit.

Preferably, this controller is powered by a conventional 12V / 24V energy storage, thus the car battery, with energy even during the accident. As a result, the triggering of the separating element may preferably be ensured. Alternatively or additionally, energy storage in the control unit, for example by suitable capacitor elements, for

Provision of triggering energy to be provided for the separating elements.

The separating elements can be designed as electromechanical or pyrotechnic separating devices. Especially with non-reversible

Separating elements, the conductive connection mechanically changed or

be destroyed. This may also exclude in particular that the Separators accidentally back to a closed state

to return. To an energy storage, in particular at

electromechanical separating elements, not to overload, they can be triggered one after the other. In the case of pyrotechnic elements, however, the required tripping energy is usually comparatively low, so that they are preferably triggered substantially simultaneously.

Separating elements 6 may be formed, for example, as a known pyrotechnic switch, in which by an explosive charge a conductive

Disconnected, for example, is pierced by a wedge element. Alternatively, an electromechanical separating element may be provided in which the function of the explosive charge is realized by the attractive or repulsive effect of an electromagnet on another element.

Preferably, the separating elements are only after opening the

Battery contactors activated. In such a case, since already by opening the battery contactors, a global current flow is suppressed, the

Separating elements for a substantially currentless switching or

Line interruption are dimensioned and thus designed to be correspondingly small.

Release speed requirements generally may not be as high as, for example, deployment of airbag systems.

In particular, like the separating elements of the invention

Battery system can be activated only after the triggering of the airbags in a vehicle to thereby also avoid an energetic overload of the vehicle systems. Such a downstream triggering may also allow the use of electromechanical switches as separating elements.

The accident detection may be done via its own sensors, in the battery control unit or using an accident detection of a central engine control unit or airbag control unit. The penetration of water into the area of the battery system is to be detected by suitably mounted sensors and evaluated as in an accident. Here, the information regarding an accident or accident and the resulting action to be taken over a vehicle data bus, such as a CAN bus, are transmitted to the ultimately triggering controller.

The display of the release of the separating elements and thus the safety of the battery system may preferably be carried out using a non-reversible display element, so that the display of the safe state is not accidentally deleted or disabled due to accident or again. The display of the triggering is thus preferably permanent and in particular mechanically operated and can in particular also the same

Use trigger mechanism, such as a pyrotechnic

Display element. The display is attached to a suitable location in the vehicle visible to the outside.

The separating elements can be designed such that a triggering that has taken place can be detected by an optical display on the element itself and / or by evaluation of the changed control properties on the triggering lines or by a separate sensor line (for example, separation of a sensor line)

Sensor loop). This may facilitate maintenance or replacement of the partitions after a damage event.

Preferably, the vehicle electronics has a suitable

Monitoring device, for example in a control unit, for

Monitoring the correct function of the separators over the entire vehicle life.

Embodiments of the invention are illustrated in the following drawings and explained in more detail in the following description.

Show it

Figure 1 shows an exemplary embodiment of a drive system for

Electric or hybrid vehicles with a battery system according to the present invention; and

Figures 2a-c exemplary embodiments of the arrangement of

Separating elements according to the present invention Still referring to FIG. 1, an exemplary embodiment of a propulsion system for electric or hybrid vehicles having a battery system according to the present invention is illustrated. Figure 1 shows the schematic structure of a drive system for a vehicle, in particular an electric or hybrid vehicle. For the propulsion of the vehicle, an electric machine 12 is provided using elements 11a-c, for example 12V battery IIa, power converter IIb and connection elements or battery contactor 11c. Further provided are exemplary for the engine and vehicle control responsible control devices

8a, b, for example, battery control unit (BCU) 8a, electronic control unit (ECU) 8b, the on

Internal Combustion Engine (ICE) or range extender engine 12 is connected.

As energy storage of the vehicle, a battery system 2 is provided, which is composed of a plurality of battery modules 4. By way of example, this battery system 2 is connected to battery contactor 11c using a fuse 18, which supplies the electric machine 10 with energy for the vehicle drive using the converter IIb. According to the invention, between the individual battery modules 4 of the battery system 2

Separating elements 6 are arranged, which suitably e.g. be connected to the battery control unit 8a and controlled by this, so that in an accident, a separation of the serial connection of the battery modules 4 is possible or controlled by this is triggered. The battery control unit 8a, in turn, may receive information relating to an accident scenario from another control device of the vehicle, for example an airbag control unit, via a data bus 14 (for example CAN bus). The connection of the battery system 2 to the vehicle can in turn be separated from the vehicle itself by dividing elements 6, which are arranged as an example outside the battery system in FIG. 1. Likewise, these separating elements can also be connected to the outwardly directed connections of the

Battery system 2 may be arranged in the housing. Display element 16 is shown only schematically in FIG. Display element 16 is preferably arranged in the vehicle at an externally suitably visible location around the outside, in particular not reversibly

Triggering of the separating elements 6 and thus to display a separation of the serial connection of the battery modules 4 in the battery system 2. By way of example, rescue or rescue forces can read from this information displayed on the display element 16 to what extent a potentially life-threatening high voltage of the battery system 2 can be converted into substantially harmless individual voltages of the individual battery modules 4

Separation of the serial interconnection was reduced.

Referring still to Figures 2a-c, exemplary embodiments of the array of separators according to the present invention are illustrated.

FIG. 2 a shows an exemplary detail of battery system 2 with two battery modules 4. The serial connection of battery modules 4 can be clearly seen in FIG. 2 a. In FIG. 2 a, separating elements 6 are arranged, for example, inside a battery module 4, thus inside its sealed housing. In the housing of a battery module 4 six battery cells are arranged by way of example, which are also connected in series and together provide the voltage of a battery module 4, for example, 12V or 24V. The

Control lines for triggering the separating elements 6 are shown in FIG. 2a

shown schematically entering the housing.

FIG. 2b differs from FIG. 2a essentially only in that the separating elements 6 are arranged outside the individual battery modules 4. The battery modules 4 thus correspond essentially to conventional ones

Battery modules, wherein the serial connection between two battery modules 4 by a guide element with an inventive arrangement of

Separating element 6 is formed. According to FIG. 2 b, already existing battery systems 2 can simply be retrofitted according to the invention, wherein, of course, the control of the separating elements 6 has to be implemented. By way of example, FIG. 2c shows an embodiment of a conductor element 20 with a separating element 6. For example, at one end of the conductor element 20, provided with an eyelet 22 for screw connection to a battery module 4, can be mounted in a housing in the cable element 20

Separating element 6 may be provided, which in turn is suitably controllable in order to separate the conductive connection in an accident case. Such cable elements can be used for (retrofitting) conversion of a conventional battery system.

Claims

claims

Battery system (2) for a vehicle, comprising

at least two battery modules (4);

wherein the battery modules (4) are connected in series;

characterized in that the battery system (2) further comprises a separator (6);

wherein the separating element (6) is arranged in series between the battery modules (4);

wherein the separator (6) is arranged to provide a substantially lossless conductive connection in a regular operation of the vehicle; and

wherein the separating element (6) is set up such that in the event of an accident the conductive connection between the battery modules (4), in particular non-reversibly, can be interrupted.

Battery system according to claim 1,

wherein the separating element (6) is designed as a non-reversible electromechanical separating element (6) or non-reversible pyrotechnic separating element (6).

Battery system according to one of the preceding claims,

wherein the separating element (6) can be coupled to a control unit (8) of the vehicle, in particular with a safety control unit or airbag control unit, and receives information relating to an accident event or a triggering signal from the control unit (8);

wherein the separating element (6) interrupts the conductive connection based on the information or by means of the triggering signal.

4. Battery system according to one of the preceding claims,

the battery modules (4) having a substantially hermetic sealed housing; and wherein the separating element is seconded in the housing of at least one battery module or in a conductor element between two battery modules.

5. Battery system according to one of the preceding claims, further comprising

a display element (16) which is arranged, in particular non-reversible, to indicate that the conductive connection between the battery modules (4) is interrupted.

6. Battery system according to one of the preceding claims, comprising a plurality of series-connected battery modules (4), which together provide an operating voltage for the drive of the vehicle;

wherein between each two serially interconnected battery modules (4) a separating element (6) is arranged;

wherein in an accident event, the conductive connections between the battery modules are separable, so that the operating voltage in a number of battery modules corresponding number of individual voltages can be divided, in particular in individual voltages of up to 24V.

7. vehicle, in particular electric or hybrid vehicle, comprising a

Battery system (2) according to one of the preceding claims.