DE102022200790A1 - Method for controlling a temperature of a battery for an electrically powered motor vehicle. - Google Patents

Abstract

Disclosed is a method for controlling a temperature range (31) of a battery (11), in particular a battery for an electrically driven motor vehicle (10), wherein a capacity of the battery (10) for storing electrical energy is temperature-dependent, having the steps: detecting a customer setting for the capacity specified in a human-computer interface (23, 24), determination of a minimum temperature (Tmin) and a maximum temperature (Tmax) between which the capacity can be reached, heating of the battery (11) if a battery temperature (BT) is below the minimum temperature (Tmin), and cooling the battery (11) when the battery temperature (BT) is above the maximum temperature (Tmin).

Description

technical field

The disclosure relates to a method for controlling a temperature of a battery for a motor vehicle that can be driven by an electric motor. A battery, as used in the disclosure, is a power source that operates optimally within a range of temperatures. A motor vehicle that can be driven by an electric motor can be driven by an electric motor, at least for short distances. The motor vehicle can be a fully electric motor vehicle, a hybrid vehicle or a mild hybrid vehicle. The battery can be a lithium ion battery, for example.

DE102019119763A1 relates to a method for treating a battery of a parked motor vehicle, having the following steps: determining a current or planned operating state of the motor vehicle, determining a current reference temperature if the current or planned operating state of the motor vehicle is a parked state, and determining an upper reference temperature, and cooling the battery if the current reference temperature is above the upper reference temperature. That in the DE102019119763A1 disclosed motor vehicle makes the cooling of the battery independently. This can result in the vehicle using more electricity than the driver expects.

Description

According to the present disclosure, a device and a method are to be specified with which this disadvantage can be remedied.

The disadvantages are remedied with the features of the independent claims. The dependent claims form advantageous developments of the disclosure. The dependent claims can be combined with one another in a technologically meaningful manner. The description, in particular in connection with the figures, additionally characterizes and specifies the disclosure.

• • Erfassen einer in eine Mensch-Rechnerschnittstelle vorgegebenen Kundeneinstellung zu der Kapazität,
• • Bestimmung einer Minimaltemperatur und einer Maximaltemperatur zwischen welchem die Kapazität erreicht werden kann,
• • Aufheizen der Batterie, wenn eine Batterietemperatur unterhalb von der Minimaltemperatur liegt, und
• • Abkühlen der Batterie, wenn die Batterietemperatur oberhalb von der Maximaltemperatur liegt.

Accordingly, a method is provided for controlling a temperature range of a battery, in particular a battery for an electrically drivable motor vehicle, with a capacity for storing electrical energy being temperature-dependent, having the steps:

• • detecting a customer setting given in a human-computer interface to the capacity,
• • determination of a minimum temperature and a maximum temperature between which the capacity can be reached,
• • heating up the battery when a battery temperature is below the minimum temperature, and
• • Cooling down the battery if the battery temperature is above the maximum temperature.

The customer setting can be a setting that is made in the motor vehicle globally for all hours of operation or limited in terms of space and time for individual journeys. The human-computer interface can be provided in a control panel in the motor vehicle. The human-computer interface can also be implemented in a mobile phone.

The customer setting can be made on the motor vehicle in a human-computer interface or via an app on a smartphone. The customer setting affects the capacity for storing electrical energy. The customer setting is only active when the vehicle is parked. The ability of the battery to store and release electrical energy depends on the temperature in a number of ways. On the one hand, a battery that is too cold or too hot can absorb less electrical energy during the charging process. When driving, when recuperating, this means that the battery cannot be charged with its maximum charging current.

Even if higher temperatures above 50°C have a particularly negative effect on the capacity, temperatures that are too low should also be avoided. At higher temperatures, not only is the ability of batteries to deliver and absorb energy reduced, but the battery also ages more rapidly as a result of lithium plating. Aging is caused by chemical and physical processes in the battery, which are usually only partially reversible or with additional effort. Low temperatures favor the formation of metallic lithium. So-called "lithium plating" can occur because both the cathode and the anode are designed to bind lithium ions. During a charging process (at a charging station or during recuperation), ions migrate from the cathode to the anode. When discharging (electric motors are driven), lithium ions flow back to the cathode. The cathode is typically formed from a lithium metal oxide. Graphite, which has a layered structure, is often used for the anode. The lithium ions are stored in these layers during charging. Instead of being stored in the anode as desired, lithium ions can also be combined kidneys and form metallic lithium (covalent bond instead of ionic bond). This lithium metal accumulates on the anode and is therefore partly no longer available for the charging process described above, thus reducing the performance of the lithium battery.

Thanks to the process mentioned above, the temperature of the battery can be controlled by the customer, depending on the requirements. A wide variety of driving situations exist and only the customer knows when the motor vehicle will be put into operation. Although the method requires energy for heating or cooling the battery, which energy may even come from the battery and reduce its capacity, heating or cooling is necessary anyway when the motor vehicle is put into operation. However, when driving, no account can be taken of the energy consumed for heating or cooling, the battery is instead heated up as quickly as possible. By pre-heating the battery as described below, it can be heated or cooled more slowly, using correspondingly less energy.

In one embodiment, it is therefore provided that the customer setting relates to a time at which the motor vehicle is to be put into operation and the battery temperature is kept above the minimum temperature and below the maximum temperature in a period of time before the time.

If the time at which the motor vehicle is to be put into operation is known in advance, the battery can be brought up to operating temperature in advance. This even increases the range, since otherwise the battery would have to be heated or cooled as quickly as possible, with the corresponding energy consumption, in the event of an unplanned start-up.

In one embodiment, the battery temperature is monitored and regulated according to customer settings when the motor vehicle is parked.

In the broadest sense, the customer setting concerns the interaction of the battery capacity with the other relevant parameters. Parameters include range, start-up performance, rate of aging, and the like. The performance at the start of the journey relates to the battery's ability to store energy during recuperation and release it during acceleration.

The period of time can be between 10 minutes and 180 minutes, in particular between 20 minutes and 120 minutes, in particular between 30 minutes and 90 minutes. Of course, a shorter period of time is necessary when the battery temperature is only a few degrees below the minimum temperature or above the maximum temperature.

• • Erfassen eines Betriebszustands, in welchem das Kraftfahrzeug geparkt wird,
• • Abfragen der Kundeneinstellung,
• • Setzen einer Default-Kundeneinstellung, in welcher die Batterie nach Beendigung eines eventuellen Ladevorgangs nicht erwärmt wird, wenn keine Eingabe der Kundeneinstellung erfolgt.

In one embodiment, the method also has the following steps:

• • detecting an operating state in which the motor vehicle is parked,
• • querying customer settings,
• • Setting a default customer setting in which the battery is not heated after the end of a possible charging process if the customer setting is not entered.

Therefore, if the driver or customer does not provide a time or battery condition, the battery may only be cooled or heated under extreme temperatures to prevent battery damage.

• • Anzeigen eines Betriebszustands, in welchem sich die Kapazität der Batterie befindet, in einer Mensch-Rechnerschnittstelle,
• • Anzeigen einer Option, die Batterietemperatur so zu regeln, dass eine maximal mögliche Ladekapazität für möglichst viele Ladevorgänge erhalten bleibt.

In one embodiment, the method also has the following steps:

• • displaying an operating state, in which the capacity of the battery is, in a human-computer interface,
• • Display an option to regulate the battery temperature so that a maximum possible charge capacity is maintained for as many charges as possible.

According to this embodiment, the customer setting is a long-term performance of the battery, with the battery temperature being monitored and controlled when the motor vehicle is parked.

The long-term performance of the battery is its ability to store and deliver electrical energy. In order to maintain long-term performance, energy from the battery itself is necessary. Consuming this energy reduces the distance that can be covered in the motor vehicle without further charging. However, the capacity that can be stored and used in future charging processes increases. To put it simply, it is up to the driver whether he wants to save the battery in the long term at the expense of the current range, or whether he finds the current range more important at the moment.

Battery heating can occur through a variety of mechanisms. Engine waste heat from an internal combustion engine can be used in a hybrid or mild hybrid vehicle. Individual battery cells can be be short-circuited with a power resistor. A parking heater can be used, which burns fuel and gives off heat to the battery. A charging current can also be used, i.e. waste heat that occurs when charging the battery anyway. The power resistor and the battery cells themselves heat up as a result. A heat pump can be used. The cooling can be done by air supply, a heat pump or a liquid cooling circuit.

One embodiment relates to a computer program product with program code means that are stored on a computer-readable data carrier in order to carry out the method described above when the computer program product is executed on a computer, in particular in control electronics of a control system. The control system can be designed and developed as described above.

One embodiment relates to a computer program with encoded instructions for carrying out the method described above when the computer program is executed on a computer, in particular control electronics of a control system. The control system can be designed and developed as described above. The computer program can be stored in particular on the computer program product described above, for example a floppy disk, CD-ROM, DVD, memory, a processor unit connected to the Internet. The computer program can in particular be in the form of a compiled or not yet compiled data sequence, which is preferably based on a higher, in particular object-based, computer language.

One embodiment relates to a signal sequence with computer-readable instructions for carrying out the method described above when the signal sequence is processed by a computer, in particular by control electronics of a control system. The control system can be designed and developed as described above. The signal sequence can be generated in particular with the aid of the computer program described above and/or with the aid of the computer program product described above. The signal sequence can be provided as electrical pulses and/or electromagnetic waves and/or optical pulses in a wireless or wired manner.

A means for implementing the method steps within the meaning of the present disclosure can be configured as hardware and/or software, in particular a processing unit, in particular a control unit with microprocessors (CPU) and/or one or more programs or program modules, preferably data or signal-connected to a memory and/or bus system. The CPU can be designed to process commands that are implemented as a program, to detect input signals from a data bus and/or to emit output signals to a data bus. The program can be stored on a storage system. The storage system can have one or more, in particular different, storage media, in particular optical, magnetic, solid and/or other non-volatile media. The program may be arranged to embody or be capable of performing the methods described herein such that the CPU can perform the steps of such methods. In one embodiment, one or more, in particular all, steps of the method can be carried out fully or partially automatically, in particular by the controller or its means.

character list

• 1: schematisch ein Kraftfahrzeug mit zwei elektrischen Motoren, die über Getriebe mit Antriebsrädern gekoppelt sind, wobei die elektrischen Motoren über eine Batterie mit elektrischer Energie versorgt werden;
• 2: Verläufe von Leistungen, welche in eine Batterie einspeisbar und entnehmbar sind, über der Temperatur aufgetragen; und
• 3: ein Diagramm eines Verfahrens, welches in einer Steuereinheit für ein Kraftfahrzeug implementiert sein kann, um die Temperatur der Batterie gemäß einem Fahrer- oder Kundenwunsch zu regeln.

The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. Show it:

• 1 : Schematic representation of a motor vehicle with two electric motors which are coupled to drive wheels via gears, the electric motors being supplied with electric energy via a battery;
• 2 : Courses of powers that can be fed into and drawn from a battery plotted against the temperature; and
• 3 1: a diagram of a method that can be implemented in a control unit for a motor vehicle in order to regulate the temperature of the battery according to a driver's or customer's request.

The following description is merely illustrative in nature. For purposes of clarity, the same reference numbers will be used throughout the drawings to designate similar elements. It should be appreciated that some steps within a method may be performed in a different order without changing the principles of the present disclosure. Steps of the method can be multiplications, summations and selections as well as assignments, for example assignments of output values to input values in characteristic diagrams.

1 shows schematically a motor vehicle 10 with a battery 11, which can deliver electrical energy to motors 13 via a frequency converter 12. The motors 13 are optionally via gear 14 with drive wheels 15 drehmo ment transferable coupleable. In possible embodiments, the battery 11 can be charged via an internal combustion engine 16 which is connected to a generator 17 . Direct drives without a gear 14 are also possible. The battery 11 can be cooled via a cooling device 18 . The cooling device 18 can contain a heat pump or only lead ambient air to the battery 11 . The battery 11 can also be heated electrically or with another form of energy via a heating device 19 . The battery 11 can be electrically connected to a charging station 26 via a charging socket 20 in order to charge the battery 11 .

The battery 11 also has at least one temperature sensor 22 that can detect a battery temperature BT in at least one area of the battery 11 . The motor vehicle 10 also has a control unit 21 which, in a manner not shown, is connected to the battery 11, the frequency converter 12, the motors, the internal combustion engine 16, the charging socket 20, the temperature sensor 22 and other components in a signal-transmitting manner.

When the battery 11 is being charged and discharged, it heats up in any case; sometimes, as a rule, no heating of the battery 11 is necessary during operation.

2 shows curves 321, 322, 331, 332 of power P [kW], which can be fed into and drawn from a battery, plotted against the battery temperature BT [°C]. It can be seen that the ability of the battery 11 to take up power and deliver power outside of the temperature range, ie below the minimum temperature Tmin and above the maximum temperature Tmax, decreases rapidly.

Curve 321 corresponds to a power consumption of a battery 11 that is discharged with pulses lasting 30 seconds. The power consumption takes place during recuperation, in which the motors 13 are operated as a generator and the battery 11 is charged. The longer the charging pulse lasts, the lower the power P that the battery 11 can store.

The curve 322 corresponds to the power output of the same battery 11, also with pulses lasting 30 seconds. The power output takes place during driving operation, in which the motors 13 drive the drive wheels 15 and, in the process, draw energy from the battery 11 .

The curve 331 corresponds to a power consumption of the same battery 11, this time with shorter pulses of 2 seconds. It can be seen that this power P [kw], which can be fed into the battery with short-lasting pulses, is also three times as high below the minimum temperature Tmin at 0°C as with long-lasting pulses according to curve 321. Curve 332 corresponds to a power output of the battery, which is also discharged with shorter-lasting pulses of 2 seconds.

In a motor vehicle, it is not known how long the driver will be braking (recuperation, charging), nor how long an acceleration phase (discharging) will last. Therefore, the minimum temperature Tmin and the maximum temperature Tmax are set in such a way that with the battery 11 used, discharging and charging is possible for processes lasting as long as desired.

3 shows a course of a method that can run in the control unit 21 in order to control the heating device 19 and the cooling device 18 of the battery 11.

In a step 41 a customer setting is queried. The query is made either in the operating unit 25 in the motor vehicle 10 at a human-computer interface 23 provided therein. Alternatively, the query is made using a mobile phone 24 with a comparable human-computer interface 23.

In a step 42 calibrated parameters are taken from a memory. The calibrated parameters can be vehicle-specific data relating to the motors 13, the battery 11 and driving behavior or a region in which the motor vehicle 10 is usually sold or operated.

In a step 43 previously stored customer settings and presets are retrieved from a memory.

The previously saved customer settings can be information about a parking process. It can be information that a charging process has ended and the charging socket 20 has been separated from the charging station 26 . It can be the last ambient temperature. There is also information on the battery temperature at the time of parking. It can also be queried whether heating or cooling of the battery 11 could be necessary at all based on the ambient temperature. If the ambient temperature is in the range between Tmin and Tmax, it may make sense not to start the cooling and heating process, since the battery temperature BT will be in the desired temperature range 31 will adjust. In addition, in step 43 information is obtained as to whether the driver entered in an earlier customer setting that the temperature of the battery 11 should always be controlled to avoid premature aging. The default settings are settings relating to the specific vehicle. These can be queried and entered at a level other than the customer setting, for example during production or maintenance of the motor vehicle 10. In step 45, the current battery temperature BT is recorded. Step 45 consumes little energy and can run continuously in the control unit.

In step 44, the current customer settings from step 41, the calibrated parameters 42, the battery temperature BT and the input parameters and default settings from step 43 are logically combined and assigned to one another. In step 46 it is queried whether the battery temperature BT is lower than the minimum temperature Tmin. If this is the case, in step 48 the battery 11 is heated via the heating device 19. In step 47 it is queried whether the battery temperature BT is greater than the maximum temperature Tmax. If this is the case, in step 49 the battery 11 is cooled via the cooling device 18.

• • Erfassen einer in eine Mensch-Rechnerschnittstelle 23 vorgegebenen Kundeneinstellung zu der Kapazität,
• • Bestimmung einer Minimaltemperatur Tmin und einer Maximaltemperatur Tmax zwischen welchem die Kapazität erreicht werden kann,
• • Aufheizen der Batterie 11, wenn eine Batterietemperatur BT unterhalb von der Minimaltemperatur Tmin liegt, und
• • Abkühlen der Batterie 11, wenn die Batterietemperatur BT oberhalb von der Maximaltemperatur Tmin liegt.

In the control unit 21 (see 1 ), a method for controlling a temperature range 31 of a battery 11 can be implemented, with a capacity of the battery 11 for storing electrical energy being temperature-dependent (see 2 ). In the simplest case, the procedure consists of the following steps:

• • detecting a customer setting given in a human-computer interface 23 for the capacity,
• • Determination of a minimum temperature Tmin and a maximum temperature Tmax between which the capacity can be reached,
• • heating up the battery 11 if a battery temperature BT is below the minimum temperature Tmin, and
• • Cooling down of the battery 11 when the battery temperature BT is above the maximum temperature Tmin.

The recording presupposes the display of the customer setting to be queried on the human-computer interface. The customer setting becomes necessary if the customer has to decide between conflicting objectives such as range, electricity costs at the charging station and the long-term durability of the battery. The customer setting can also be made by the customer if it relates to a time when the motor vehicle is started up.

The time is the time at which the motor vehicle 10 is to be put into operation. The battery temperature BT is kept above the minimum temperature Tmin and below the maximum temperature Tmax within the time required for this. How long the time required for this is depends on the deviation of the battery temperature BT from the temperature range 31 .

It is provided that the battery temperature BT is monitored and regulated when the motor vehicle 10 is parked.

• • Erfassen eines Betriebszustands, in welchem das Kraftfahrzeug 10 geparkt wird,
• • Abfragen der Kundeneinstellung,
• • Setzen einer Default-Kundeneinstellung, in welcher die Batterie 11 nach Beendigung eines eventuellen Ladevorgangs nicht erwärmt wird, wenn keine Eingabe der Kundeneinstellung erfolgt.

The customer may forget or ignore the customer setting. Especially if he doesn't understand her and would rather not make an adjustment than make a wrong choice. The following steps can therefore also be implemented in parallel or after a special event has occurred in the control unit 21:

• • detecting an operating state in which the motor vehicle 10 is parked,
• • querying customer settings,
• • Setting a default customer setting in which the battery 11 is not heated after the end of a possible charging process if the customer setting is not entered.

The default setting can provide for cooling to take place only when the maximum temperature Tmax is exceeded, in order to avert damage to the battery.

• • Anzeigen eines Betriebszustands, in welchem sich die Kapazität der Batterie 11 befindet, in einer Mensch-Rechnerschnittstelle 23,
• • Anzeigen einer Option, die Batterietemperatur BT so zu regeln, dass eine maximal mögliche Ladekapazität für möglichst viele Ladevorgänge erhalten bleibt.

The following steps can also be implemented to ensure the longest possible battery life:

• • displaying an operating state, in which the capacity of the battery 11 is, in a human-computer interface 23,
• • Displaying an option to regulate the battery temperature BT in such a way that a maximum possible charging capacity is maintained for as many charging processes as possible.

Furthermore, it can be provided that the method is also carried out at a charging station 26 when the battery 11 is fully charged. A customer setting is required here, as heating or cooling the battery can cause a chargeable power consumption. The customer should not be surprised by this.

Although at least one exemplary embodiment has been presented in the foregoing description as well as the description of the figures, it should be recognized that a large number of variations exist. Furthermore, it should be recognized that the embodiment(s) are only examples and are not intended to limit the scope, applicability, or precise form in any way. Rather, the description and description of the figures provide useful guidance for those skilled in the art for implementing at least one embodiment, it being understood that various changes in form and function of the described features may be made without departing from the scope of the claims and their equivalents.

Reference List

10

motor vehicle

11

battery

12

frequency converter

13

Engines

14

transmission

15

drive wheels

16

combustion engine

17

generator

18

cooling device

19

heating device

20

charging socket

21

control unit

22

temperature sensor

23

human-computer interface

24

mobile phone

25

control panel

26

charging station

31

temperature range

41

Step

42

Step

43

Step

44

Step

45

Step

46

Step

47

Step

48

Step

49

Step

321

Course

322

Course

331

Course

332

Course

BT

battery temperature

min

minimum temperature

Tmax

maximum temperature

P [kW]

Performance

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102019119763 A1 [0002]

Claims (10)

Method for controlling a temperature range (31) of a battery (11), in particular a battery for an electrically drivable motor vehicle (10), wherein a capacity of the battery (11) for storing electrical energy is temperature-dependent, having the steps: • detecting a customer setting for the capacity that is specified in a human-computer interface (23, 24), • Determination of a minimum temperature (Tmin) and a maximum temperature (Tmax) between which the capacity can be reached, • heating the battery (11) when a battery temperature (BT) is below the minimum temperature (Tmin), and • Cool down the battery (11) if the battery temperature (BT) is above the maximum temperature (Tmin). procedure after claim 1 , wherein the customer setting relates to a time at which the motor vehicle (10) is to be put into operation and the battery temperature (BT) is kept above the minimum temperature (Tmin) and below the maximum temperature (Tmax) in a period of time before the time. procedure after claim 1 and/or 2, the battery temperature (BT) being monitored and regulated when the motor vehicle (10) is parked. Method according to one or more of the preceding claims, comprising the steps: • detecting an operating state in which the motor vehicle (10) is parked, • querying customer settings, • Setting a default customer setting in which the battery is not heated after the end of a possible charging process if the customer setting is not entered. Method according to one or more of the preceding claims, comprising the steps: • displaying an operating state, in which the capacity of the battery (11) is, in a human-computer interface (23), • Display an option to regulate the battery temperature (BT) in such a way that a maximum possible charge capacity is maintained for as many charges as possible. Method according to one or more of the preceding claims, wherein the method is also carried out at a charging station (26) when the battery (11) is fully charged. Control unit (21) for controlling a battery (11) according to a method according to one of Claims 1 until 6 . Computer program product with program code means, which are stored on a computer-readable data medium, in order to implement the method according to one of Claims 1 until 6 carried out if the computer program product on a computer, in particular a control unit (21). claim 7 is performed. Computer program with encoded instructions for performing the method according to any one of Claims 1 until 6 , if the computer program on a computer, in particular a computer in a control unit (21). claim 7 is performed. Signal sequence with computer-readable instructions for carrying out the method according to any one of Claims 1 until 6 , if the signal sequence from a computer, in particular a control unit (21). claim 7 is processed.

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