DE102016224548A1 - Method for operating an electrical energy storage system and corresponding machine-readable storage medium, electronic control unit and electrical energy storage system - Google Patents

Abstract

A method for operating an electrical energy storage system is described, wherein the electrical energy storage system comprises at least one electrical energy storage unit, and steps described below are performed. An aging state variable representing an aging state of the electric energy storage system is determined. Furthermore, a product size which does not represent a physical or chemical quantity is read out of a data memory and the electrical energy storage system is controlled in dependence on the determined aging state variable and the readout product size in such a way that the quality of the electrical energy storage system is optimized.

Description

The present invention is based on a method for operating an electrical energy storage system, a corresponding machine-readable storage medium, a corresponding electronic control unit, a corresponding electrical energy storage system and a corresponding use.

State of the art

The life of an electrical energy storage system is usually shorter than the life of an entire system in which the electrical energy storage system is installed. For example, the life of an electric vehicle is usually longer than the life of a built-in electric vehicle high-voltage battery. Also, a possible resale value of an electric vehicle depends on the lifetime and other variables. These other variables include, for example, the cost of a new high-voltage battery. Since the electrical energy storage system, in this case the high-voltage battery, possibly also operated bidirectionally, so both energy and can deliver what is compensated, an optimized, application-specific operation of the electrical energy storage system in consideration of the surrounding overall system and suitable Gütegrgrößen is desirable.

The publication DE 10 2013 225 748 A1 describes a method for the demand-oriented use of an electrochemical energy store, wherein a temperature value is determined.

The publication DE 10 2011 089 150 A1 describes a method for determining the state of a battery, wherein an ultrasonic measurement is used and a database is used with reference data sets of the states.

The publication DE 10 2013 018 405 A1 describes a method for determining an estimation parameter representing the state of a battery, wherein the estimation parameter is determined using a support vector machine.

Disclosure of the invention

Advantages of the invention

A method is disclosed for operating an electrical energy storage system, which comprises at least one electrical energy storage unit, with the steps described below. In this case, an aging state variable representing an aging state of the electrical energy storage system is determined. Furthermore, a grade that does not represent a physical or chemical quantity is read from a data store. The data memory can be, for example, an external database or even a memory chip integrated in an electronic control unit. The above steps can be performed in any order. Subsequently, the electrical energy storage system is controlled in response to the determined aging state variable and the read size of the product such that the Güektröße the electrical energy storage system is optimized. Thus, it is advantageously ensured that for the optimum operation of the electrical energy storage system in addition to the consideration of an aging state relevant size and at least one size is taken into account, which has no physical or chemical meaning, resulting in a variety of new application scenarios, such as the consideration of a current electricity tariff or possible opportunity costs during operation. An aging state variable may include, for example, a resistance value, a capacitance value or a storable electrical energy content of the electrical energy storage system or of the at least one electrical energy storage unit.

Further advantageous embodiments of the present invention are the subject of the dependent claims.

Expediently, an effect of at least one control variable course, in particular of a course of current flow, on the goods size is determined, for example by means of a mathematical simulation, ie without applying the control variable course to a real system. An effect can be, for example, a change in the size of the goods. A control variable course comprises one or more control variable values for one or more points in time. This has the advantage that the effects of different control variable courses can be compared and evaluated simulatively, for example due to different boundary conditions or different calculation horizons for the control variable courses. Different boundary conditions may include different maximum and minimum current values. Different calculation horizons mean that control variables are available for a different number of times, the distance of which from one another may vary as well. Between times, preferably the control amount value of the previous time is used. Application-specific, the selection of an optimal control variable course is possible. If the energy storage system has switching options, can Similarly, the effects of various switch positions, even in combination, for example, with a current waveform, are determined.

Expediently, the goods size is determined using data which is read out by means of a wireless and / or wired data connection from a database arranged outside the electrical energy storage system. Subsequently, a storage of the determined size of the goods takes place in the data memory. This has the advantage that it is possible to resort to up-to-date data which was not yet available when the electrical energy storage system was put into operation, which increases the number of possible uses of the method and improves the quality of the determined product size.

Expediently, at least one boundary condition which is to be observed in the activation of the electrical energy storage system according to the invention or the determination of the effects according to the invention is queried. This can be done directly by a user of the electrical energy storage system, for example via a touch screen or, for example, via the query of stored in a database boundary conditions. This has the advantage that a user or user of the method can easily adapt the method to his personal requirements, for example by specifying a maximum current value or a time until which a charging process of the energy storage system should be completed.

Expediently, the effect determined according to the invention, for example a change in the size of the goods, is reproduced, which can be done, in particular, visually with respect to a user. This is followed by obtaining the consent of a user with the effect determined according to the invention. This has the advantage that an effect of a possible control variable course is easily apparent and can be used to evaluate the control variable course in terms of its suitability. Visual representation vis-à-vis a user facilitates the evaluation and is expediently used for the clear presentation of various effects that are displayed side by side and preferably simultaneously. This enables the user to consciously agree to an impact, as he knows various consent options.

Expediently, the quality of the goods comprises a quality parameter, in particular a monetary quantity, for example a residual value of the energy storage system. Thus, a very relevant for the user size in the operation of the electrical energy storage system is taken into account.

Appropriately, the aging state variable includes a vehicle range, wherein the vehicle range is determined, for example, based on a maximum storable energy content or a maximum capacity of the electrical energy storage system, an electrical resistance of the electrical energy storage system and a mean electrical energy consumption of a vehicle, wherein the electrical energy storage system is installed in the vehicle , This has the advantage that a variable directly relevant to the user of the electrical energy storage system flows into the optimized operation of the electrical energy storage system.

Conveniently, an agreement to a predefined usage scenario of the electrical energy storage system, which includes at least one predefined boundary condition, is requested. The consent can for example be requested from a user of the method. This has the advantage that a quick selection of several boundary conditions is possible, which are embedded in an easy-to-understand usage scenario. Thus, the usage scenario represents a bundling of boundary conditions that is easy to understand for the user, which he can quickly overview.

Furthermore, the subject matter of the disclosure is a machine-readable storage medium on which a computer program is stored, wherein the computer program is set up to carry out all steps of the method according to the invention. Thus, a simple distribution of the method or its use in computer systems is possible.

Furthermore, the subject matter of the disclosure is an electronic control unit which is set up to carry out all the steps of the method according to the invention. Thus, a simple use of the method in electrical energy storage systems, for example in vehicles, feasible.

Furthermore, an electrical energy system is disclosed which comprises at least one electrical energy storage unit, a data memory and an electronic control unit according to the invention. Thus, the electrical energy storage system directly receives the advantages that have been mentioned for the inventive method. In addition, an optimal vote of the process on the electrical energy storage system is possible.

Furthermore, a use of the method according to the invention or of the electrical energy storage system according to the invention in electrically driven vehicles including hybrid vehicles, in stationary electrical energy storage systems and in electrically operated hand tools is disclosed.

An electrical energy storage unit may in particular be understood as meaning an electrochemical battery cell and / or a battery module having at least one electrochemical battery cell and / or a battery pack having at least one battery module. For example, the electric energy storage unit may be a lithium-based battery cell or a lithium-based battery module or a lithium-based battery pack. In particular, the electrical energy storage unit may be a lithium-ion battery cell or a lithium-ion battery module or a lithium-ion battery pack. Furthermore, the battery cell may be of the type of lithium-polymer accumulator, nickel-metal hydride accumulator, lead-acid accumulator, lithium-air accumulator or lithium-sulfur accumulator or more generally an accumulator of any electrochemical composition. A capacitor is possible as an electrical energy storage unit.

Alternatively or in addition to the mathematical models, maps may be used which, for example, are calculated to be off-line, i. in advance calculated models or experimentally generated. Thus, a determination process can be accelerated, which is particularly advantageous for use of the method in vehicles, as there are computing time and memory equipment for a control unit on which the process may take place, are limited.

list of figures

Advantageous embodiments of the invention are illustrated in the figures and explained in more detail in the following description.

• 1 ein Flussdiagramm des erfindungsgemäßen Verfahrens gemäß einer ersten Ausführungsform;
• 2 ein Flussdiagramm des erfindungsgemäßen Verfahrens gemäß einer zweiten Ausführungsform;
• 3 ein Flussdiagramm des erfindungsgemäßen Verfahrens gemäß einer dritten Ausführungsform; und
• 4 eine schematische Darstellung einer Wiedergabe von ermittelten Auswirkungen gemäß einer Ausführungsform.

Show it:

• 1 a flowchart of the method according to the invention according to a first embodiment;
• 2 a flowchart of the inventive method according to a second embodiment;
• 3 a flowchart of the inventive method according to a third embodiment; and
• 4 a schematic representation of a representation of detected effects according to an embodiment.

Embodiments of the invention

Identical reference signs denote the same device components or the same method steps in all figures.

1 shows a flowchart of the method according to the invention according to a first embodiment. In a first step S1, a maximum vehicle range for a built-in vehicle electrical energy storage system is determined. This can be done using a mathematical model of the electrical energy storage system, such as that of FIG H. He, R. Xiong and J. Fan in the article "Evaluation of Lithium-ion Battery Equivalent Circuit Models for State of Charge Estimation by an Experimental Approach," Energies, Vol. 4, No. 12, pp. 582-598 , March 2011 described, suitable model parameter values, which can be determined for example by means of experiments, such as resistance values, and an average electrical energy consumption of the vehicle. Subsequently, in a second step S2, a current monetary residual value of the electrical energy storage system is read from a data store of a central database. Subsequently, in a third step S3, the electrical energy storage system is controlled in dependence on the determined maximum vehicle range and the read-out residual value such that the residual value of the electrical energy storage system is optimized. This can be done, for example, by the use of model-predictive control and control methods, as described by R. Findeisen, L. Imsland, F. Allgöwer and BA Foss in the journal article "State and Output Feedback Nonlinear Model Predictive Control: An Overview", European Journal of Control, Vol. 9, No. 2, pp. 190-206, 2003 , to be discribed. The corresponding control of the electrical energy storage system can be done by a suitable power electronics, such as a power converter. For example, the use of the electrical energy storage system as a bidirectional energy storage on the power grid can increase the residual value of the electrical energy storage system, since money is earned or can be earned by this use. A simultaneous aging through use is accepted, as the monetary costs of aging are less than the revenues generated by the use of electricity. This can be a suitable model for the life prediction or Aging prediction can be used with appropriate monetary quantification in the control or regulatory process.

2 shows a flowchart of the inventive method according to a second embodiment. In a first step S1a, a resistance value is determined which represents an aging state of an electrical energy storage system. Optionally, this may be done using a mathematical model for the electrical energy storage system. Subsequently, in a second step S2a, the monetarily quantifiable gain achieved so far with the electrical energy storage system, which can be positive or negative, is read from a data memory. In a third step S4, an update of the profit is subsequently carried out using data from an external database, for example electricity tariffs and / or residual values and / or replacement values, resulting in an achievable, monetarily quantifiable gain, which can be positive or negative. In a fourth step S5, the effects of different current magnitude profiles on the recoverable profit are then determined simulatively. For example, it may be cheaper in the current electricity rates, the power grid to provide any electrical energy from the electrical energy storage system available, since a corresponding remuneration is too low and thus the costs can not be compensated or exceeded by aging of the electrical energy storage system. In a fifth step S6, the recoverable gain and, if appropriate, the associated control variable course, if appropriate with associated boundary conditions, are then stored in the data memory. In a sixth step S3a, the electrical energy storage system is then controlled in dependence on the determined resistance value and the recoverable gain with the associated control variable profile such that the recoverable profit - as determined in the determination of the recoverable profit or in the determination of the effects - is optimized, which Maximizing the profit. For example, revenues from services for the power grid, such as the feeding or receiving of electrical energy, then realize at least part of the profit that can be achieved. Other parts, such as revenue from the sale of the electrical energy storage system, are only realized when actually selling the same, but are used as an arithmetic variable in the profit calculation.

3 shows the inventive method according to a third embodiment. In a first step S1b, a capacitance, ie a maximum storable charge quantity, of an electrical energy storage system is determined. This can be done, for example, using a mathematical model of the electrical energy storage system, for example, an electrical equivalent circuit model. In a second step S2b, a quality parameter is subsequently read from a data memory. This quality parameter takes into account, for example, the amount of charge that has been taken or supplied to the energy storage system, the frequency with which a specific voltage threshold has been exceeded or exceeded, the frequency with which a certain current threshold has been exceeded or undershot, an indication of how much CO2 is emitted by the Operation of the electrical energy storage system could be saved, and aggregates these variables, for example, as desired and weighting of a user in a value of the quality parameter. Subsequently, in a third step S7, at least one boundary condition is queried, for example by a user or also from a database, which is to be adhered to when the electrical energy storage system is actuated and / or when determining the effects of a control variable course. This may be, for example, a predetermined point in time, up to which the energy storage system has to be fully charged or up to a certain charge state, and / or a temperature, in particular an average temperature, which the electrical energy storage system must have reached by a certain point in time. Also, for example, the specification of the fastest possible charging of the electrical energy storage systems and / or as much CO2-saving charging is conceivable, which can be realized by knowing the current power mix. A combination of the mentioned boundary conditions is possible. For example, these can be combined into one or more predefined usage scenarios, which simplifies and accelerates a query of boundary conditions. Subsequently, in a fourth step S5a, the determination of the effects of a plurality of current magnitude profiles possible under the preselected boundary conditions on the quality characteristic, for example with mathematical optimization means using a suitable model for lifetime prediction and a suitable model of the electrical energy storage system. Thus, a current flow profile can be found that optimizes the quality parameter under the given boundary conditions. In a fifth step S8, at least one selection of the determined effects is displayed to a user, for example on the basis of the representation of the different values for the quality characteristic by means of corresponding numerical values, so that the user can make a selection under different effects. With the different ones Impacts are linked to corresponding boundary conditions. This is exemplified in 4 clarified and described. In a sixth step S9, the user's consent is obtained with an effect. This effect is linked to the corresponding boundary conditions. Subsequently, in a seventh step S3b, the electrical energy storage system is controlled in dependence on the ascertained capacity and the read quality characteristic taking into account the selected boundary conditions in such a way that the quality parameter of the electrical energy storage system is optimized. Due to the fact that mostly mathematical models, including the electric energy storage system, which do not represent the reality to 100% accurate, are used to determine the effects of the different control variable courses, it can happen that the current flow curves from the determination of the effects and the actually realized flow characteristics differ. Therefore, when driving the electrical energy storage system, the boundary conditions to be considered important. For example, a method of model-predictive control can be used to optimize the size of the product, as described, for example, in the above-mentioned journal article by Findeisen et al. is described. The steps mentioned can also be automated, for example by using stored preferences of a user / user and, for example, obtaining the consent of the user by default is considered to exist. The user has, for example, once agreed to an automated implementation and automatically selects the boundary conditions for the control of the electrical energy storage system, which result in the determination of the effects of the largest or smallest quality parameter value in comparison. A restriction of the approval to certain usage scenarios is conceivable.

4 shows a schematic representation of a representation of detected effects according to an embodiment. On a display 40 are different bars 41 . 42 . 43 visualized. These bars, together with the values written above them, represent the effects of different control variables on a product size. The product size belonging to a control quantity profile is shown above the corresponding bar. In addition, in the lower area of the bars, the associated usage scenarios are each indicated by a symbol 44 . 45 . 46 specified. From this it can be seen that there are at least five usage scenarios, of which the effects of three, namely scenario 2 , Scenario 5 and scenario 1 , are reproduced. A user can now consent to the associated usage scenario by simply tapping a bar.

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102013225748 A1 [0003]
• DE 102011089150 A1 [0004]
• DE 102013018405 A1 [0005]

Cited non-patent literature

• H. He, R. Xiong and J. Fan in the article "Evaluation of Lithium-ion Battery Equivalent Circuit Models for State of Charge Estimation by an Experimental Approach," Energies, Vol. 4, No. 12, pp. 582-598 , March 2011 [0024]
• R. Findeisen, L. Imsland, F. Allgöwer and BA Foss in the journal article "State and Output Feedback Nonlinear Model Predictive Control: An Overview", European Journal of Control, Vol. 9, No. 2, pp. 190-206, 2003 [0024]

Claims (12)

A method of operating an electrical energy storage system, comprising at least one electrical energy storage unit, wherein the following steps are carried out: a) determining an aging state quantity representing an aging state of the electric energy storage system; b) reading a grade that does not represent a physical or chemical quantity from a data store; c) driving the electrical energy storage system as a function of the determined aging state variable and the read size of the goods such that the Güektröße the electrical energy storage system is optimized. Method according to Claim 1 , further comprising the step of: d) determining an effect of at least one control variable course, in particular of a course of current flow, on the quality of the goods. Method according to one of the preceding claims, further comprising the steps: e) determining the size of the product using data that is read out by means of a wireless and / or wired data connection from a database arranged outside of the electrical energy storage system. f) storing the determined goods size in the data memory. Method according to one of the preceding claims, further comprising the step: g) querying at least one boundary condition which must be adhered to in the control in step c) and / or the determination in step d). Method according to one of Claims 2 to 4 , further comprising the step of: h) reproducing the effect determined in step d), in particular by visually presenting it to a user; i) obtaining an agreement from a user with the effect from step d). Method according to one of the preceding claims, wherein the goods size comprises a quality parameter, in particular a monetary quantity. Method according to one of the preceding claims, wherein the aging state quantity comprises a vehicle range. Method according to Claim 4 , wherein an approval to a predefined usage scenario, which includes at least one predefined boundary condition, is queried. A machine-readable storage medium on which a computer program is stored, the computer program being arranged to perform all the steps of the method according to any one of Claims 1 to 8th perform. Electronic control unit, which is set up all the steps of the procedure according to one of Claims 1 to 8th perform. Electrical energy storage system, comprising at least one electrical energy storage unit, a data storage and an electronic control unit according to Claim 10 , Use of a method according to one of Claims 1 to 8th or an electrical energy storage system according to Claim 11 in electrically powered vehicles including hybrid vehicles, in stationary electrical energy storage systems and in electrically powered hand tools.

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