Method for adapting charging current for charging process of electrochemical energy store as function of temperature

Abstract

The invention relates to a method for adapting a charging current for a charging process of at least one electrochemical energy store of an electrically drivable vehicle as a function of the temperature.

Description

Field of the Invention

[0001] The present invention relates to a method for adapting a charging current of a charging process for at least one electrochemical energy storage for an electrically driven vehicle according to temperature, a device for operating an electrochemical energy storage, a computer program, and / or a use scenario of a method for adapting a charging current of a charging process for an electrochemical energy storage for an electrically driven vehicle according to temperature. Background Art

[0002] In the future, electrically driven heavy trucks will be charged at charging stations with high electrical power ("megawatt charging"). There is a disadvantage in the prior art that battery cooling is lacking or insufficient, which ultimately means a loss of driving range because energy cannot be charged into the battery during the cooling phase.

[0003] Especially for electrically driven heavy vehicles, time is an important factor in order to be able to receive as much energy as possible during a specified parking interval.

[0004] Document DE 10 2011 089 293 A1 discloses a method for controlling battery charging for a vehicle.

[0005] Document DE 10 2021 206 010 A1 discloses a system and method for battery pre-cooling.

[0006] The object of the present invention is to further improve the prior art. This object is achieved by the features of the independent claims. Summary of the Invention

[0007] Advantages of the Invention

[0008] In contrast, the method according to the invention having the features of the characterizing part of the independent claim has the advantage that the method for adapting a charging current of a charging process for at least one electrochemical energy storage for an electrically driven vehicle according to temperature comprises the following steps:

[0009] - Determining a maximum charging current parameter, which represents the maximum allowable charging current related to the temperature of the electrochemical energy storage;

[0010] - Detecting an actual temperature parameter, which represents at least one instantaneous temperature of the electrochemical energy storage;

[0011] - Determining a target charging current parameter according to the detected actual temperature parameter by means of the maximum charging current parameter, which represents the allowable charging current for the electrochemical energy storage at the instantaneous temperature;

[0012] - Adapt the charging current of the charging process for an energy storage device for electrochemistry according to a target charging current parameter.

[0013] When a predefined temperature limit value is not exceeded, especially in the case of a lack or insufficiency of cooling of the electrochemical energy storage device, the interruption during the charging process can be advantageously reduced. Thereby, for example, as much energy as possible can also be stored in the electrochemical energy storage device during the short intermittent time of a truck driver. This can be advantageously achieved with the maximum feasible charging current even at high temperatures without shutdown being effected by the battery management system (BMS) of the electrochemical energy storage device.

[0014] Here, the charging current enters into the "Derating" type and is accordingly reduced. This means for the charging process that an electrically driven vehicle, such as an electrically driven truck (LKW), can be charged with a temperature-dependent maximum charging current and not with the maximum current that can be provided by the charging station and can reach up to several thousand amperes.

[0015] In this method according to the invention, the charging current is predefined by a correspondingly set temperature profile of the electrochemical energy storage device, which charging current is usually at least a few minutes. Thereby, pulse charging is not advantageously effected in the high frequency range.

[0016] Further advantageous embodiments are the subject matter of the dependent claims.

[0017] The determination of the target charging current parameter is advantageously effected such that the maximum charging current of the charging current level is achieved according to the temperature of the electrochemical energy storage device without interrupting the charging process due to thermal heating of the electrochemical energy storage device.

[0018] Therefore, compared to an electrochemical energy storage device with a very good cooling system, although less energy is supplied by the method according to the invention, significantly more energy is still supplied compared to a priority assignment scheme that would determine and interrupt the charging process.

[0019] The method for adapting the charging current of the charging process for an electrochemical energy storage device for an electrically driven vehicle according to temperature according to any one of the preceding claims further comprises the following steps:

[0020] - Compare the target charging current parameter with a predefined target charging current threshold;

[0021] - When the target charging current parameter is lower than the target charging current threshold, charge the electrochemical energy storage device with a first charging current type representing alternating current; or

[0022] - When the target charging current parameter exceeds the target charging current threshold, charge the electrochemical energy storage device with a second charging current type representing direct current.

[0023] The combination of alternating current and direct current can be implemented in a favorable manner with a CCS plug. The charging current type is not limited to direct current or alternating current. For example, when only a small current is allowed, the combination can also be transformed from direct current to alternating current in a favorable manner.

[0024] The maximum charging current parameter is stored in a family of temperature-dependent characteristic curves and takes into account additional parameters, especially the state of health (SOH) of the electrochemical energy storage device, and the inertia of the thermal system of the electrochemical energy storage device.

[0025] The family of temperature-dependent characteristic curves advantageously includes data of the single cells of the electrochemical energy storage device according to the data sheets of the single cell manufacturers. The inertia of the thermal system takes into account not only exceeding the temperature limit value but also a safety margin so that countermeasures can be taken in a timely manner with a smaller charging current.

[0026] The charging current parameter is stored in the controller of the electrochemical energy storage device and / or in the controller of a charging device that can be connected to the electrochemical energy storage device, and / or the target charging current parameter is determined by the controller of the electrochemical energy storage device and / or the controller of the charging device.

[0027] The charging current for the charging process of the electrochemical energy storage device is adapted by the controller of the electrochemical energy storage device and / or the controller of the charging device.

[0028] The device for operating the electrochemical energy storage device includes at least one temperature sensor for detecting the temperature of the electrochemical energy storage device, and at least one device, especially an electronic battery management controller, which is configured to perform the steps of the method according to the invention, and the method adapts the charging current of the charging process of the electrochemical energy storage device for an electrically driven vehicle according to the temperature.

[0029] According to an advantageous design of the invention, a computer program is provided, which includes instructions that cause the device for operating the battery to implement the method steps according to the invention.

[0030] Furthermore, a machine-readable storage medium is provided, on which the computer program is stored.

[0031] The method according to the invention for adapting the charging current of the charging process of an electrochemically energy storage for an electrically driven vehicle to the temperature and / or a device for operating an electrochemically energy storage are advantageously used in an electrochemically energy storage for an electric vehicle, an electric heavy vehicle, a fuel cell vehicle, a hybrid vehicle, a plug-in hybrid vehicle, an aircraft, an electric scooter and / or an electric bicycle. Description of the Drawings

[0032] Embodiments of the invention are shown in the drawings and are explained in detail in the following description. Among them:

[0033] Figure 1 A schematic curve of the charging current related to the temperature is shown; and

[0034] Figure 2 A schematic diagram of a flowchart of an embodiment of the method according to the invention is shown. Detailed Description of the Invention

[0035] The same reference numerals denote the same device components in all the figures.

[0036] Figure 1 A schematic curve of the charging current 100 related to the temperature is shown.

[0037] The duration t of the charging process is plotted on the abscissa, the charging power P related to the charging current is plotted on the first ordinate, and the temperature T of the electrochemically energy storage is plotted on the second ordinate.

[0038] The electrochemically energy storage is first charged at a charging power P of 50 kW at a first charging current level 101(1). Therefore, in an exemplary first time period 104, the temperature curve 102 of the electrochemically energy storage decreases.

[0039] Since time point t1, the electrochemically energy storage is charged at a charging power P of 160 kW at a second charging current level 101(2). Therefore, in an exemplary second time period 105, the temperature curve 102 of the electrochemically energy storage rises. The maximum temperature 103 will cause the interruption of the charging process or the degradation of the charging priority. Before reaching this maximum temperature, the charging current is reduced to a third charging current level 101(3), whereby the charging power P drops from 160 kW to 50 kW and the electrochemically energy storage is thus cooled.

[0040] Thus, in an adverse situation, the charging current varies back and forth between two current intensities. However, the charging process does not change between a charging and a non-charging state, which advantageously enables continuous charging.

[0041] Therefore, the charging current always varies below a pre-given temperature limit and advantageously stores the maximum energy in the electrochemical energy storage. Thus, although cooling of the electrochemical energy storage (which would also allow a higher charging current) is not achieved, it is continuously charged.

[0042] Figure 2 A schematic diagram showing a flowchart of an embodiment of the method according to the invention is shown.

[0043] In a first step 200, a maximum charging current parameter is determined, which represents the maximum allowable charging current related to the temperature T of the electrochemical energy storage.

[0044] In step 201, an actual temperature parameter is detected, which represents at least one instantaneous temperature T of the electrochemical energy storage.

[0045] In step 202, a target charging current parameter is determined based on the detected actual temperature parameter by means of the maximum charging current parameter, which represents the allowable charging current for the electrochemical energy storage at the instantaneous temperature T.

[0046] In step 203, the charging current for the charging process of the electrochemical energy storage is adapted according to the target charging current parameter.

Claims

1. A method for adapting a charging current (100) of a charging process of at least one electrochemical energy storage for an electrically driven vehicle according to temperature, the method comprising the following steps: -(200) determining a maximum charging current parameter (103), which represents the maximum allowable charging current related to the temperature (T) of the electrochemical energy storage; -(201) detecting an actual temperature parameter, which represents at least one instantaneous temperature (T) of the electrochemical energy storage; -(202) determining a target charging current parameter according to the detected actual temperature parameter by means of the maximum charging current parameter (103), which represents the allowable charging current for the electrochemical energy storage at the instantaneous temperature (T); -(203) adapting the charging current (100) of the charging process for the electrochemical energy storage according to the target charging current parameter.

2. A method for adapting a charging current (100) of a charging process of an electrochemical energy storage for an electrically driven vehicle according to temperature, as claimed in claim 1, wherein The determination of the target charging current parameter is achieved such that the maximum charging current related to the temperature (T) of the electrochemical energy storage at the charging current level (101(1), 101(2), 101(3)) is reached without interrupting the charging process due to the thermal rise of the electrochemical energy storage.

3. The method for adapting a charging current (100) of a charging process of an electrochemical energy storage for an electrically driven vehicle according to temperature according to any one of the preceding claims, the method further comprising the following steps: - comparing the target charging current parameter with a pre-given target charging current threshold; - when the target charging current parameter is lower than the target charging current threshold, charging the electrochemical energy storage with a first charging current type, which represents alternating current; or - when the target charging current parameter exceeds the target charging current threshold, charging the electrochemical energy storage with a second charging current type, which represents direct current.

4. A method for adapting a charging current (100) of a charging process of an electro-chemical energy storage for an electrically driven vehicle according to temperature, according to any one of the preceding claims, wherein The maximum charging current parameter is stored in a temperature-related characteristic curve family and other parameters are considered, especially the state of health (SOH) of the electrochemical energy storage and the inertia of the thermal system of the electrochemical energy storage.

5. A method for adapting a charging current (100) of a charging process of an electro-chemical energy storage for an electrically driven vehicle as a function of temperature according to any one of the preceding claims, wherein The charging current parameter is stored in the controller of the electrochemical energy storage and / or in the controller of a charging device that can be connected to the electrochemical energy storage, and / or the target charging current parameter is determined by the controller of the electrochemical energy storage and / or the controller of the charging device.

6. A method for adapting a charging current (100) of a charging process of an electro-chemical energy storage for an electrically driven vehicle as a function of temperature, wherein, The charging current of the charging process for the electrochemical energy storage is adapted by the controller of the electrochemical energy storage and / or the controller of the charging device.

7. Device for operating an electrochemical energy storage, said device comprising at least one temperature sensor for detecting the temperature (T) of the electrochemical energy storage, and at least one device, in particular an electronic battery management controller, which is set up to carry out the steps of a method for adapting the charging current of a charging process of an electrochemical energy storage for an electrically driven vehicle as a function of temperature according to any one of claims 1 to 6.

8. Computer program, which comprises instructions that cause the device according to claim 7 to carry out the method steps according to any one of claims 1 to 6.

9. Machine-readable storage medium, on which the computer program according to claim 8 is stored.

10. Use scenario of the method for adapting the charging current of a charging process of an electrochemical energy storage for an electrically driven vehicle as a function of temperature according to any one of claims 1 to 6 and / or of the device for operating an electrochemical energy storage according to claim 7 in an electrochemical energy storage for an electric vehicle, an electric heavy vehicle, a fuel cell vehicle, a hybrid vehicle, a plug-in hybrid vehicle, an aircraft, an electric scooter and / or an electric bicycle.

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