DE102015200276A1 - Device and method for discharging a battery cell and battery module Battery, battery system, vehicle, computer program and computer program product - Google Patents

Abstract

The invention relates to a device for discharging a battery cell to be discharged (1121, ... 112m) in a battery (1000), comprising a plurality of battery cells (1kl1, ... 1klm) and a plurality of switching devices (2kl1, ... 2klm, 200; 500; 5001, ... 5003), characterized by determining means (410) for determining the battery cell (1121, ... 112m) to be discharged, and an actuator (430) for operating switching means of the plurality of switching means (2kl1, ... 2klm, 200; 500; 5001, ... 5003) such that a discharge current can flow from the battery cell (1121, ... 112m) to be discharged via the actuated switching devices, a battery module, a battery, a battery system, a vehicle, a method for discharging a battery cell, a computer program, and a computer program product.

Description

State of the art

It is foreseeable that both in stationary applications, for example in wind turbines, and in mobile applications, for example in electric vehicles (EV), hybrid electric vehicles (HEV) or plug-in hybrid electric vehicles, PHEV), as rechargeable electrical energy storage (EES, electro-chemical storage system, ESS) increasingly new battery systems or battery modules, for example with lithium-ion batteries, will be used.

A battery system comprises a multiplicity of battery cells, for example cylindrical or prismatic battery cells or battery cells with electrode coils (battery cell coil, cell coil, Jerry Roll, JR). The battery cells can be connected in series (series) to increase the voltage and / or connected in parallel to increase the maximum electric current and capacity. Thus, the battery cells can be combined into battery modules or battery units. When used to drive vehicles, for example, about 100 battery cells (as a traction battery) can be connected in series or in parallel.

Out DE 10 2011 076 515 A1 is already an energy storage device for generating an n-phase supply voltage, wherein n> = 1, with n parallel-connected power supply branches, which are each connected to one of n phase terminals, each of the power supply branches having a plurality of series-connected energy storage modules, each one Energy storage cell module, which has at least one energy storage cell, and a coupling device with coupling elements which are adapted to selectively switch or bypass the energy storage cell module in the respective power supply branch, wherein those coupling elements of the coupling means, which are adapted to the energy storage cell module in the respective Power supply branch to bridge, include self-conductive semiconductor switches. The remaining coupling elements may include self-locking semiconductor switch.

A battery system with an integrated converter may include, for example, a direct converter or a direct inverter. In this case, battery cells or battery modules can be operated to vary the phase voltage with currents over frequency ranges up to the kilohertz (kHz) range.

The permissible temperature range for operation of the battery cells is typically between +5 ° C and +40 ° C. In the lower range of the operating temperature, the performance of the battery cells can be significantly reduced. At temperatures below about 0 ° C, the internal resistance of the battery cells increases sharply, and the performance and efficiency of the battery cells continue to decrease as temperatures continue to fall. In this case, an irreversible damage to the battery cells can occur. Even if the operating temperature is exceeded, the performance of the battery cells may decrease significantly. At temperatures above approx. 40 ° C, the service life of the battery cells is reduced, regardless of whether the thermal energy (Joule heat energy, thermal energy) is released in the battery cells or supplied externally. As a result, irreversible damage to the battery cells can likewise occur. The damage can lead to an accelerated aging of the battery cells or, when a limit temperature of 130 ° C to 170 ° C, to a self-sustaining exothermic reaction (thermal runaway) of the battery cells, which can lead to cell blight or a cell explosion, for example, and thus pose a danger to humans and the environment.

For a fast but defined discharge, a battery cell is usually short-circuited in an error case by means of a safety device, for example, safety circuit with its cell housing. The electrical energy is converted directly into heat energy in the battery cell where the fault is present. In addition, mechanical safety devices, for example, internal pressure-based safety devices are comparatively inaccurate and error-prone.

However, in order to increase the safety of accumulators (batteries) and accumulator systems (battery systems), it is necessary to provide an apparatus and method for discharging battery cells.

Disclosure of the invention

The devices and methods according to the invention with the features of the independent claims have the advantage that the heat energy released when discharging a battery cell, for example in the event of a fault, at least partially, outside of this battery cell. Thus, the heat energy is not released in the battery cell that is damaged or the battery module that is damaged. As a result, the safety of the battery module or the battery can be increased. Furthermore, the heat energy can be released distributed over several components. Thus, a thermal load of each Component can be reduced. Furthermore, a period for unloading can be shortened. As a result, a rapid discharge of the battery can be provided. Furthermore, the current when discharging defined set, for example, controlled or regulated. This allows a controlled unloading can be achieved. Thus, damage to the components by discharging can be prevented. Furthermore, the devices and methods according to the invention can be integrated, for example, in a battery system with an integrated converter and a direct inverter. In addition, after discharging the faulty and / or damaged battery cell or the faulty and / or damaged battery module further operation of the battery can be made possible. Thus, for example, a further journey of a vehicle can be achieved. Thus, the availability of the battery or the vehicle can be achieved.

Advantageous embodiments of the present invention are described in the dependent claims.

Conveniently, determining the battery cell to be discharged may include monitoring the plurality of battery cells to detect a critical condition in the battery cell to be discharged. As a result, one or each battery cell of the plurality of battery cells can be discharged if it has a critical, for example, safety-critical state.

Conveniently, the actuation of the switching means may include monitoring or adjusting the discharge current. As a result, the discharge of the battery cell can be defined.

Conveniently, the plurality of switching devices may be arranged in a plurality of coupling devices. Thereby, the structure and / or the control of the battery modules can be simplified.

Conveniently, the plurality of switching devices may be formed as a plurality of power switching devices such as power switches such as semiconductor switches, power transistors, power field effect transistors (FETs), self-blocking power field effect transistors or metal oxide field effect transistors (MOSFETs). Thereby, the structure of the switching devices and the control of the switching devices can be simplified. Furthermore, the switching devices can be operated in linear mode. Thus, heat energy can be released at the switching devices. Thus, the switching devices can perform an additional function in the unloading operation. Furthermore, the released heat energy can be better delivered and distributed.

Conveniently, the discharge current to internal resistances of the actuated switching devices can release thermal energy. Thus, the released heat energy can be better delivered and distributed.

Conveniently, the discharge current at a resistive element or semiconductor element associated with one of the actuated switching devices can release thermal energy. As a result, the released heat energy can be delivered and distributed even better.

Conveniently, the plurality of battery cells may be arranged in a plurality of battery modules. As a result, the structure of the battery can be modularized. As a result, assemblies can be standardized. Thus, the maintenance and repair can be simplified. Furthermore, costs can be reduced.

Conveniently, the plurality of battery cells may be arranged in a plurality of battery module strings. As a result, the structure of the battery can be further modularized. Furthermore, the battery can provide a multi-phase supply voltage. Thus, the versatility of the battery can be increased.

Conveniently, the discharge current may flow within a battery module string of the plurality of battery module strings in which the battery cell to be discharged is arranged. As a result, unloading can be achieved particularly easily. Additionally, another battery module string or other battery module strings may provide a supply voltage to the plurality of battery module strings during discharge. Thus, the battery can provide emergency operation during unloading. This can improve the availability and increase the reliability of the battery.

Conveniently, the discharge current can flow through a discharge path of the battery module string. This allows the construction to be carried out particularly easily. Thus, the battery can provide emergency operation during unloading. As a result, the availability can be further improved and the reliability of the battery can be further increased

Conveniently, an actuated switching device of the actuated switching devices may be arranged in the discharge path. As a result, the structure of the discharge path can be simplified.

Conveniently, the discharge current through a common discharge path of the plurality of battery module strings flow. This can reduce a number of unloading paths. Thus, weight and cost can be reduced.

Conveniently, another actuated switching means of the actuated switching means may be arranged in the common discharge path. As a result, the structure of the discharge path can be simplified.

Conveniently, the discharge current may flow over another battery module string or other battery module strings of the plurality of battery module strings. As a result, the discharge paths or the common discharge path can be omitted. Thus weight and costs can be further reduced.

The invention further provides a battery module comprising the device described above.

The invention further provides a battery comprising the previously described device or battery module described above.

The invention further provides a battery system comprising the apparatus described above, the previously described battery module or the previously described battery.

The invention further provides a vehicle, in particular motor vehicle such as electric motor vehicle, hybrid vehicle, plug-in hybrid vehicle or electric motorcycle (electric bike, e-bike), electric bicycle (Pedal Electric Cycle, Pedelec), a maritime vehicle such as electric boat or submarine (submarine) , an aircraft or a spacecraft, including the device previously described and connected to the vehicle, the battery module previously described and connected to the vehicle, the battery previously described and connected to the vehicle, or the battery system previously described and connected to the vehicle ,

The invention further provides corresponding methods.

The invention further provides a computer program stored on a data carrier or in a memory of a computer and comprising computer readable instructions for executing one of the methods described above when the instructions are executed on the computer.

The invention further provides a computer program product comprising the computer program described above.

It is within the scope of the invention not necessarily to carry out the method steps in the order described. In a further embodiment, the method steps can also be interleaved (interleaving).

Furthermore, it is possible that individual sections of the described method can be designed as individual salable units and remaining sections of the method as other salable units. Thus, the method according to the invention can be executed as a distributed system on different computer-based instances, for example client-server instances. For example, it is possible for a module to include different sub-modules.

Other features and advantages of the present invention will become apparent to those skilled in the art from the following description of exemplary embodiments, which should not be construed as limiting the invention, with reference to the accompanying drawings.

1 shows a circuit diagram of a battery module 10 according to an embodiment of the invention,

2 shows a simplified circuit diagram of the battery module 10 .

3 shows a circuit diagram of a battery system 30 according to the embodiment of the invention in normal operation,

4 shows a circuit diagram of the battery system 40 in the discharge operation via a battery module string 100 ₂ ,

5 shows a circuit diagram of the battery system 50 in unloading operation via two battery module strings 100 ₂ , 100 ₃ ,

6 shows a schematic diagram of another battery system 60 with discharge path in the battery module strings 100 ₁ , ... 100 ₃ according to another embodiment of the invention in the unloading operation, and

7 shows a circuit diagram of another battery system 70 with a common discharge path for the battery module strings 100 ₁ , ... 100 ₃ according to another embodiment of the invention in the unloading operation.

1 shows a circuit diagram of a battery module 10 according to an embodiment of the invention.

The battery module 10 or one Lth battery module 10 _kl in a k th battery module string 100 _k includes a plurality m of battery cells 1 _kl1 , ... 1 _klm , which, as in 1 shown as an example, are electrically connected in series, a variety of switching devices 2 _kl1 , ... 2 _kl4 and a first, for example, positive electrical battery module connection (module connection, connection) 7 _kl1 and a second example negative electrical battery _{module connection} 7 _kl2 . The switching devices 2 _kl1 , ... 2 _kl4 can, as in 1 shown as an example, be designed as a self-locking FETs and their protection in each case a freewheeling diode 3 _kl1 , ... 3 _kl4 include. The switching devices 2 _kl1 , ... 2 _Cl4 are so among themselves and with the large number of battery _cells 1 _kl1 , ... 1 _klm connected that the first connection 7 _kl1 and the connection 7 _kl2 with the multitude of battery _cells 1 _kl1 , ... 1 _{klm are} connected, for example, when the switching devices 2 _kl1 and 2 _kl4 closed and the switching devices 2 _kl2 and 2 _{kl3 are} open (see battery _module 10 ₁₂ in 4 - 7 ), and the first connection 7 _kl1 and the connection 7 _kl2 are interconnected when the switching devices 2 _kl3 and 2 _kl4 closed and the switching devices 2 _kl1 and 2 _{kl1 are} open (see battery _module 10 ₁₁ in 4 - 7 ).

The battery module 10 . 10 _kl can continue to use a variety of temperature _{measuring devices} 4 _kl1 , ... 4 _klm , each one of the multitude of battery cells 1 _kl1 , ... 1 _{klm are} associated to measure a cell temperature at or in the associated battery cell. The temperature measuring devices can, as in 1 shown as temperature sensors such as temperature-dependent resistors such as resistors with positive temperature coefficient (PTC resistors) or resistors with a negative temperature coefficient (NTC resistors) may be formed.

The battery module 10 . 10 _kl can continue a current measuring device 5 _kl, for example, for measuring a current in the plurality of battery cells 1 _kl1 , ... 1 _klm or from the large number of battery cells 1 _kl1 , ... 1 _klm and / or a voltage _{measuring device} 6 _kl, for example, for measuring a voltage of the plurality of battery cells 1 _kl1 , ... 1 _klm include.

The battery module 10 . 10 _kl can continue to use an interface device 9 _kl with a connection 8th _kl for communication with a control device and / or processing means for processing measured values. The communication over the connection 8th For example, _kl can be parallel, serial, multiplexed and / or via a bus such as fieldbus.

2 shows a simplified circuit diagram of the in 1 shown battery module 10 . 10 _kl , that in 3 to 7 is used. The simplified switching shows the multiplicity of battery cells 1 _kl1 , ... 1 _klm and the variety of switching devices 2 _kl1 , ... 2 _cl4 .

3 shows a circuit diagram of a battery system 30 according to the embodiment of the invention in normal operation.

The battery system 30 includes a battery 1000 having a plurality k of battery module strings (module strings, strands) 100 ₁ , ... 100 ₃ includes. The battery module strings 100 ₁ , ... 100 ₃ each include a plurality 1 of battery modules 10 ₁₁ , ... 10 _3l , with respect to the 1 and 2 described battery modules 10 . 10 _kl correspond, and a first example positive electrical battery module strand connection (strand connection, connection) 7 ₁₁ , 7 ₃₁ and a second, for example negative electrical battery module strand connection 7 ₁₂ , 7 ₃₂ . As in 3 shown by way of example, the battery system 30 from three battery module strings 100 ₁ , ... 100 _{3 shows} a three-phase supply voltage for operating an electrical machine, for example a motor 300 via a three-pole motor switching device 200 create and deploy. The engine switching device 200 can be used as a motor switching device such as motor switch, the three single-pole switch 20 ₁ , ... 20 ₃ , be formed. The battery system 30 can be designed for example as a DINV battery system.

The battery system 30 further comprises a control device 400 for controlling the battery system. The control device 400 includes determination means 410 and an actuator 430 , The determining device 410 can be designed as a processing device such as microprocessor or microcontroller. The actuating device 430 is with the connections 8th _{kl of} the battery modules 10 ₁₁ , ... 10 _3l and the three-pole motor _{switching device} 200 connected and may be formed as an interface device. The control device 400 can continue a storage device 420 for storing instructions and / or data such as measured values. The storage device 420 can be designed as a volatile and / or non-volatile memory.

In normal operation, the control device controls 400 the battery modules 10 ₁₁ , ... 10 _3l such that the battery 1000 the engine 300 provides a three-phase supply voltage.

Furthermore, the control device 400 Measured values from the temperature measuring devices 4 _kl , ... 4 _kl , current measuring equipment 5 _kl and / or voltage _{measuring devices} 6 _kl der battery modules 10 ₁₁ , ... 10 _3l capture and evaluate the measured values.

When the controller 400 in the processed measured values, preferably taking into account a current load of the battery modules 10 ₁₁ , ... 10 _3l or variety of battery cells 1 ₁₁₁ , ... 10 _3lm , _detects a critical or impermissible state, the control device 400 a battery cell, which has the critical state, as described below, discharged and thus reach a non-critical, safe or stable state for this battery cell or the associated battery module.

4 shows a circuit diagram of the battery system 40 in the discharge operation via a battery module string 100 ₂ .

The battery system 40 corresponds to that with respect to 3 described battery system 30 , The control device 400 has, for example, the battery cell 1 _{121 of} the affected battery module 10 _{12 of} the affected module string 100 ₁ due to an impermissibly high temperature of the battery cell 1 _{121 determines} a critical state. To achieve the uncritical state, the battery cell 1 ₁₂₁ over the adjacent second module string 100 ₂ unloaded. To unload the battery cell 1 ₁₂₁ the in 4 Close (highlighted by stronger lines) highlighted circuit closes the control device 400 by means of the actuating device 430 the switching devices 2 ₁₂₁ , 2 _{124 of} the affected battery module 10 ₁₂ , so its connections 7 ₁₂₁ , 7 ₁₂₂ with the multitude of its battery cells 1 ₁₂₁ , ... 1 _{12m are} connected, the switching devices (lower switching devices, low-side switches) 2 ₁₁₃ , 2 ₁₁₄ , 2 _1l3 , 2 _{1l4 of} the remaining battery _modules 10 ₁₁ , 10 _{1l of} the affected module string 100 ₁ , so that their respective terminals are connected together, the three-pole motor switching device 200 that the connections 7 ₁₁ , ... 7 _{31 of} the plurality of module strands 10 ₁ , ... 10 ₃ connects to a star point and the engine 300 from the battery 1000 separates, and the switching devices 2 ₂₁₃ , 2 ₂₁₄ , 2 ₂₂₃ , 2 ₂₂₄ , 2 _2l3 , 2 _{2l4 of} all battery _modules 10 ₂₁ , ... 10 _{2l of} the adjacent module _string 100 ₂ , so that their respective terminals are connected to each other while at least some of the remaining switching devices are opened. Alternatively, the control device 400 by means of the actuating device 430 for one or more battery modules 10 _kl also the switching devices 2 _kl1 , 2 _kl4 close and the switching devices 2 _kl2 , 2 _kl3 open so that his / her connections 7 _kl1 , 7 _kl2 with the variety of his / her battery _cells 1 _kl1 , ... 1 _{klm are} connected. This will increase the electrical energy of the battery cell 1 ₁₂₁ or the affected battery module 10 ₁₂ due to their conduction resistance (on-resistance) in the closed switching devices as power loss in thermal energy released. To adapt or optimize the discharge, the control device 400 adjust or increase the conduction resistances so that the switching devices operate in linear mode instead of in switching operation. In this case, the control device 400 adjust the conduction resistances for each switching device individually, so that the power losses in the switching devices can be distributed uniformly or according to a predetermined distribution. Furthermore, the control device 400 by monitoring the discharge to achieve power matching, thus minimizing the time required for unloading.

For a battery module comprising two lithium-ion battery cells with a cell nominal voltage of 3.6 V and a cell internal resistance (R _i ) of 1 mΩ as battery cells and four MOSFETs as switching devices, the following exemplary model calculation results. For a battery module with two lithium-ion battery cells with a nominal cell voltage of 3.6 V, which are connected in series, results in a battery module voltage of 7.2 V. For a switching device with an on-resistance (R _{drain-source (on)} , R _{DS (on)} ) of 0.137 mΩ. For a battery module string with 48 switching devices, a total turn- _on resistance (ΣR _{DS (on)} ) of 6.56 mΩ results for these 48 switching devices and a total resistance (ΣR) of 2 R _i + ΣR _{DS (on)} for the two battery cells and the 48 switching devices. = 2 × 1 mΩ + 6.56 mΩ = 8.56 mΩ.

For a temperature-dependent change in resistance between junction temperatures (T _J ) of 25 ° C and 150 ° C, a temperature coefficient R _{DS (on) 150 ° C} / ΣR _{DS (on) 25 ° C} of 2 results.

For a in 4 shown circuit with the affected battery module string 100 ₁ connected in series with a battery module string 100 ₂ (or 100 ₃ ) result, without consideration of internal resistance of lines and the engine switching device 200 and junction _resistances , for a junction temperature of 25 ° C a maximum current (I _{max25 ° C} ) of 476.2 A and a power dissipation per MOSFET (P _{25 ° C} ) of 30.99 W and for a junction temperature of 150 ° C a maximum Current (I _{max 150 ° C} ) of 238.1 A and a power dissipation per MOSFET (P _{150 ° C} ) of 15.50 W.

When the controller 400 In the processed measured values, the achievement of the uncritical, safe or stable state detected, it can unload the battery cell 1 ₁₂₁ finish.

The following are with reference to the 5 to 7 further circuits for unloading described.

5 shows a circuit diagram of the battery system 50 in unloading operation via two battery module strings 100 ₂ , 100 ₃ .

The battery system 50 corresponds to that with respect to 4 described battery system 40 , to Achieving the uncritical state, the battery cell 1 ₁₂₁ over the adjacent second module string 100 ₂ and the third module string 100 _{3 are} discharged. To unload the battery cell 1 ₁₂₁ the in 5 to close highlighted circuits, closes the control device 400 by means of the actuating device 430 in addition, the switching devices 2 ₃₁₃ , 2 ₃₁₄ , 2 ₃₂₃ , 2 ₃₂₄ , 2 _3l3 , 2 _{3l4 of} all battery _modules 10 ₃₁ , ... 10 _{3l of} the third module string 100 ₃ , so that their connections are connected to each other.

For a in 5 shown circuit with the affected battery module string 100 ₁ connected in series with the battery module strings connected in parallel 100 ₂ and 100 ₃ result, without consideration of internal resistance of lines and the engine switching device 200 and transition _resistances , for a junction temperature of 25 ° C a maximum current (I _{max25 ° C} ) of 608.1 A and a power dissipation per MOSFET (P _{25 ° C} ) of 50.54 W and for a junction temperature of 150 ° C a maximum Current (I _{max 150 ° C} ) of 304.1 A and a power dissipation per MOSFET (P _{150 ° C} ) of 25.27 W.

6 shows a schematic diagram of another battery system 60 with discharge path in the battery module strings 100 ₁ , ... 100 ₃ according to another embodiment of the invention in the unloading operation.

The battery system 60 is essentially the same as with reference to 4 described battery system 40 , To achieve the uncritical state, the battery cell 1 ₁₂₁ via a discharge path of the affected module string 100 ₁ , with the connections 7 ₁₁ and 7 _{12 is} connected, unloaded. To unload the battery cell 1 ₁₂₁ the in 6 to close the highlighted circuit closes the control device 400 by means of the actuating device 430 the switching devices 2 ₁₂₁ , 2 _{124 of} the affected battery module 10 ₁₂ , so its connections 7 ₁₂₁ , 7 ₁₂₂ with the multitude of its battery cells 1 ₁₂₁ , ... 1 _{12m are} connected, the switching devices 2 ₁₁₃ , 2 ₁₁₄ , 2 _1l3 , 2 _{1l4 of} the remaining battery _modules 10 ₁₁ , 10 _{1l of} the affected module string 100 ₁ , so that their respective terminals are connected together, and a switching device 500 ₁ , in the discharge path of the affected module string 100 _{1 is} arranged while at least some of the remaining switching means are opened.

For a in 6 shown circuit with the affected battery module string 100 ₁ connected in series with the discharge path of the affected module string 100 ₁ result, without consideration of internal resistance of lines and the switching device 500 ₁ and _{contact resistances} , for a junction temperature of 25 ° C a maximum current (I _{max25 ° C} ) of 841.1 A and a power dissipation per MOSFET (P _{25 ° C} ) of 96.69 W and for a junction temperature of 150 ° C. maximum current (I _{max 150 ° C} ) of 420.6 A and a power dissipation per MOSFET (P _{150 ° C} ) of 48.34 W.

7 shows a circuit diagram of another battery system 70 with a common discharge path for the battery module strings 100 ₁ , ... 100 ₃ according to another embodiment of the invention in the unloading operation.

The battery system 70 is essentially the same as with reference to 4 described battery system 40 , To achieve the uncritical state, the battery cell 1 ₁₂₁ via a common discharge path for the plurality of module strands 100 ₁ , ... 100 ₃ , each of the connectors 7 ₁₁ and 7 ₁₂ , 7 ₂₁ and 7 ₂₂ or 7 ₃₁ and 7 ₃₂ connected can be discharged. To unload the battery cell 1 ₁₂₁ the in 7 to close the highlighted circuit closes the control device 400 by means of the actuating device 430 the switching devices 2 ₁₂₁ , 2 _{124 of} the affected battery module 10 ₁₂ , so its connections 7 ₁₂₁ , 7 ₁₂₂ with the multitude of its battery cells 1 ₁₂₁ , ... 1 _{12m are} connected, the switching devices 2 ₁₁₃ , 2 ₁₁₄ , 2 _1l3 , 2 _{1l4 of} the remaining battery _modules 10 ₁₁ , 10 _{1l of} the affected module string 100 ₁ , so that their respective terminals are connected together, the three-pole motor switching device 200 that the connections 7 ₁₁ , ... 7 _{31 of} the plurality of module strands 10 ₁ , ... 10 ₃ connects with each other while the engine 300 from the battery 1000 separates, and a switching device 500 disposed in the common discharge path while at least some of the remaining switching devices are opened. In this case, the engine switching device 200 as engine disconnecting device such as motor disconnector, which comprises three single-pole disconnect switch, be formed.

For a in 7 shown circuit with the affected battery module string 100 ₁ connected in series with the common discharge path result, without consideration of internal resistance of lines and the switching device 500 and transition _resistances , again for a junction temperature of 25 ° C, a maximum current (I _{max25 ° C} ) of 841.1A and a power dissipation per MOSFET (P _{25 ° C} ) of 96.69W and for a junction temperature of 150 ° C maximum current (I _{max 150 ° C} ) of 420.6 A and a power dissipation per MOSFET (P _{150 ° C} ) of 48.34 W.

Finally, it is noted that terms such as "comprising" and "having" or the like do not preclude that further elements or steps may be provided. The numbers used are merely exemplary, such that a plurality may include two, four, five, six, or more elements or steps. It should also be noted that articles such as "a" or "One" exclude no variety. Furthermore, it is noted that numerals such as "first", "second", etc., are only for discriminating elements and steps without specifying an order of arrangement of elements or execution of steps. In addition, the features described in connection with the various embodiments may be combined with each other as desired. Finally, it is noted that the reference signs in the claims should not be construed as limiting the scope of the claims.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• DE 102011076515 A1 [0003]

Claims (12)

Device for discharging a battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) in a battery ( 1000 ) comprising a plurality of battery cells ( 1 _kl1 , ... 1 _klm ) and a plurality of switching devices ( 2 _kl1 , ... 2 _klm , 200 ; 500 ; 500 ₁ , ... 500 ₃ ), characterized by: - a determination device ( 410 ) for determining the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ), and - an actuator ( 430 ) for actuating switching devices of the plurality of switching devices ( 2 _kl1 , ... 2 _klm , 200 ; 500 ; 500 ₁ , ... 500 ₃ ) such that a discharge current from the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) can flow over the actuated switching devices. The device of claim 1, wherein: - determining the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) monitoring the plurality of battery cells ( 1 _kl1 , ... 1 _klm ) for detecting a critical condition in the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ), - the actuation of the switching devices comprises monitoring or adjusting the discharge current, - the plurality of switching devices ( 2 _kl1 , ... 2 _klm ) is arranged in a plurality of coupling devices, - the plurality of switching devices ( 2 _kl1 , ... 2 _klm , 200 ; 500 ; 500 ₁ , ... 500 ₃ ) is formed as a plurality of power switching devices, circuit breakers, semiconductor switches, power transistors, power field effect transistors or self-blocking power field effect transistors, - the discharge current to internal resistances of the actuated switching devices can release thermal energy, or - the discharge current to a resistive element or semiconductor element associated with one of the actuated switching devices , can release thermal energy. The device according to claim 1 or 2, wherein: - the plurality of battery cells ( 1 _kl1 , ... 1 _klm ) in a multiplicity of battery modules ( 10 ; 10 _kl ; 10 ₁₁ , ... 10 _3l ) is arranged, - the plurality of battery cells ( 1 _kl1 , ... 1 _klm ) in a plurality of battery _{module strings} ( 100 ₁ , ... 100 ₃ ), - the discharge current within a battery module string ( 100 ₁ ) the plurality of battery module strings ( 100 ₁ , ... 100 ₃ ), in which the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) is arranged to flow, - the discharge current via a discharge path of the battery module string ( 100 ₁ ), - an actuated switching device ( 500 ₁ ) of the actuated switching devices is arranged in the discharge path, - the discharge current through a common discharge path of the plurality of battery module strands ( 100 ₁ , ... 100 ₃ ), - another actuated switching device ( 500 ) of the actuated switching devices is arranged in the common discharge path, or - the discharge current via another battery module line or other battery module lines ( 100 ₂ , 100 ₃ ) the plurality of battery module strings ( 100 ₁ , ... 100 ₃ ) can flow. Battery module ( 10 ), comprising: - the device according to one of claims 1 to 3. Battery ( 1000 ), comprising: - the device according to one of claims 1 to 3, or - the battery module according to claim 4. Battery system, comprising: - the device according to one of claims 1 to 3, - the battery module ( 10 ) according to claim 4, or - the battery ( 1000 ) according to claim 5. A vehicle comprising: - the device according to one of claims 1 to 3 connected to the vehicle, - the battery module ( 10 ) according to claim 4, connected to the vehicle, - the battery according to claim 5, connected to the vehicle, or - the battery system according to claim 6, connected to the vehicle. Method for discharging a battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) in a battery ( 1000 ) comprising a plurality of battery cells ( 1 _kl1 , ... 1 _klm ) and a plurality of switching devices ( 2 _kl1 , ... 2 _klm , 200 ; 500 ; 500 ₁ , ... 500 ₃ ), characterized by: - determining the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ), and - actuating switching devices of the plurality of switching devices ( 2 _kl1 , ... 2 _klm , 200 ; 500 ; 500 ₁ , ... 500 ₃ ) such that a discharge current from the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) can flow over the actuated switching devices. The method of claim 8, wherein: determining the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) monitoring the plurality of battery cells ( 1 _kl1 , ... 1 _klm ) for detecting a critical condition in the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ), the actuation of the switching devices comprises monitoring or adjusting the discharge current, The plurality of switching devices ( 2 _kl1 , ... 2 _klm ) is arranged in a plurality of coupling devices, - the plurality of switching devices ( 2 _kl1 , ... 2 _klm , 200 ; 500 ; 500 ₁ , ... 500 ₃ ) is formed as a plurality of power switching devices, circuit breakers, semiconductor switches, power transistors, power field effect transistors or self-blocking power field effect transistors, - the discharge current to internal resistors of the actuated switching devices can release thermal energy, or - the discharge current to a resistive element or semiconductor element associated with one of the actuated switching devices , can release thermal energy. The method of claim 8 or 9, wherein: - the plurality of battery cells ( 1 _kl1 , ... 1 _klm ) in a multiplicity of battery modules ( 10 ; 10 _kl ; 10 ₁₁ , ... 10 _3l ) is arranged, - the plurality of battery cells ( 1 _kl1 , ... 1 _klm ) in a plurality of battery _{module strings} ( 100 ₁ , ... 100 ₃ ), - the discharge current within a battery module string ( 100 ₁ ) the plurality of battery module strings ( 100 ₁ , ... 100 ₃ ), in which the battery cell to be discharged ( 1 ₁₂₁ , ... 1 _12m ) is arranged to flow, - the discharge current via a discharge path of the battery module string ( 100 ₁ ), - an actuated switching device ( 500 ₁ ) of the actuated switching devices is arranged in the discharge path, - the discharge current through a common discharge path of the plurality of battery module strands ( 100 ₁ , ... 100 ₃ ), - another actuated switching device ( 500 ) of the actuated switching devices is arranged in the common discharge path, or - the discharge current via another battery module line or other battery module lines ( 100 ₂ , 100 ₃ ) the plurality of battery module strings ( 100 ₁ , ... 100 ₃ ) can flow. A computer program stored on a computer disk or memory and comprising computer readable instructions for carrying out the method of any one of claims 8 to 10 when the instructions are executed on the computer. A computer program product comprising the computer program of claim 11.

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