Control method for a battery system

Abstract

The present invention relates to a control method for a battery system which is designed for use in an electric vehicle. In order to improve a control method for battery systems such that it permits changes in a current pulse concept in adaptation to particular elementary storage cells used, and preventatively counteracts a rapidly advancing ageing of the storage cells in a more reliable manner, the invention proposes that the control method for implementing a current pulse concept is adjusted accordingly to a respective battery system with the cell types provided therein and their designs and cell chemistry, wherein a current above a permitted constant current is used and the control is carried out on the basis of an estimate of a temperature change in the storage cells.

Description

[0001]Control method for a battery system The present invention relates to a control method for a battery system, in particular a battery system for use in an electric vehicle. It is known from the prior art that, in particular for use in electric vehicles, a battery system is provided which is made up of a large number of elementary storage cells which are permanently connected to one another in series and / or parallel in order to achieve predetermined electrical connection properties defined by an operating voltage and a maximum current. There are currently very different cell types for such elementary storage cells, each with different structures and different cell chemistries, which from a technical point of view each exhibit very different behaviors during operation.Depending on the manufacturer, design, cell chemistry, cell type, and use in a particular application, there are correspondingly different concepts for setting the permissible current of a battery system in the charging and / or discharging direction. So-called current pulse concepts are a good option for briefly permitting current flows in a battery system in both operating directions that are higher than the maximum currents specified by the manufacturer. This enables higher performance of the battery system in question. However, depending on the design, cell type, cell chemistry, cell manufacturer, and use in a particular application, there are different current pulse concepts. Replacing individual components within a battery system usually results in changes to the respective current pulse concept.This requires new developments of a current pulse concept, or at least complex changes to an existing current pulse concept. The present invention has the object of improving a control method for battery systems in such a way that it allows for significantly easier changes to a current pulse concept in adaptation to the elementary storage cells used in each case and also more reliably counteracts rapidly advancing aging of the storage cells. This object is achieved according to the invention by the features of claim 1 in that the control method with implementation of a current pulse concept is adjusted accordingly to a respective battery system with the cell types provided therein, their designs and their cell chemistry, wherein a current above a permissible constant current is used and the control takes place on the basis of an estimate of a temperature change in the storage cells.A method according to the invention is therefore based on the realization that obtaining the most accurate possible knowledge of a core temperature within elementary storage cells is much more difficult than reliably estimating a temperature change within elementary storage cells caused by a respective external measure. Instead of a core temperature that can never be precisely determined, the invention considers an increase or decrease in the amount of heat as a temperature change resulting from regulating the current flow, i.e., heating due to periods of charging or discharging, as well as periods of cooling through heat dissipation or active cooling. By appropriately compensating for positive temperature changes, a storage cell is better maintained over an operating period in a temperature range in which aging of the storage cell progresses comparatively slowly.This extends the overall reliable service life of the storage cell. Furthermore, setting options are provided for mapping a particular battery system, as well as the types, designs, and / or cell chemistries of the elementary storage cells used therein, into a control method according to the invention. Accordingly, according to the invention, different characteristics of cell types and cell chemistries of a battery system can be mapped through setting options in the control method for a current pulse concept.Without extensive adaptation work or even a completely new development of a control method, it is advantageously possible according to the invention to - use a control method with a current pulse concept for many different cells and battery systems; - take into account the peculiarities of different cells via the setting options of the concept; - reliably adhere to manufacturer limitations, in particular with regard to a maximum current flow and internal heating through the control method and - achieve maximum performance of the battery system in question, taking into account all manufacturer specifications for the elementary storage cells used, with the longest possible service life. Advantageous further developments are the subject of the dependent claims. Accordingly, individual peculiarities of the current pulse concept as well as dependencies on a respective application case are used in a parameterized manner in the algorithm.A mapping of individual characteristics of the current pulse concept as well as dependencies on a particular application is therefore variably adaptable and adjustable via various predefined parameters, as explained in more detail below using exemplary embodiments with reference to the drawing. Accordingly, in a preferred embodiment of the invention, different pulse lengths of current pulses of different strengths are used in a parameterized manner. For example, short, but high current pulses are differentiated from lower, longer-lasting current pulses. In one embodiment of the invention, this differentiation is made differently in the charging and discharging directions. This will also be discussed in more detail using exemplary embodiments of the invention. Furthermore, the corresponding current pulse characteristic maps are mapped in a database using an operating temperature and a state of charge, or SOC for short.This database, which is linked to the algorithm of the control method, is accessed in a method according to the invention depending on the cell types used in the respective battery system. In a further development of the invention, a waiting or rest period required after a respective current pulse is stored in the database. This waiting or rest period is read from the database as a value for a counter and adjusted. A respective value takes into account, in particular, equalization processes in the elementary storage cells, such as those that occur after a charging or discharging pulse. Essentially, compensation for any additional heating by dissipation or heat removal through cooling measures is considered in order to prevent ever-increasing heating within the battery system.According to a key development of the invention, a dependency of a temperature change in the storage cells on a type or form of current pulse is parameterized. The different current pulses are preferably provided with an indication as to whether different types of current pulses may be used in combination with one another. This information is also stored in the database. Preferably, a counter is used to monitor and regulate the respective current pulses and the associated waiting times. The current pulse concept thus allows, for example, after a respective pulse has been used, a permissible constant current to flow until the application of the next current pulse of a respective type or form is permitted again. Furthermore, in a development, the database specifies whether an interruption of a respective current pulse is permitted.This means that in addition to the temporal segmentation of a current pulse of a particular type or form, a changed thermal load on the storage cells is also taken into account in the control method using an additional parameter. In a further embodiment of the invention, a parameter in the database is used as a flag to specify whether counters for the pulses may be counted down over time or the time axis. The flag designates a status indicator that is used in the method or software to identify this state. During this time, it is permissible in one embodiment of the invention for the counter in question to even continue counting up overall due to the occurrence of corresponding pulses with corresponding values ​​for the counter while counting down.A countdown will thus be overcompensated, whereby instead of heat dissipation a further positive temperature change is displayed and taken into account accordingly in the control. In a further development of the invention, it is provided that a current flow is assigned to a pulse height for each flow direction of the current based on the heating of the respective battery system. This means that different threshold values, maximum pulse durations, waiting times and / or decay rates for reducing the respective counter or counters can also be assigned to the respective pulse heights for each flow direction. The control method described above with various further developments is preferably integrated as software in a battery management system. Further features and advantages of embodiments according to the invention are explained in more detail below with reference to exemplary embodiments using the drawing.Shown are: Figure 1: a time course of two example pulses; Figure 2: a time course of a sequence of pulses in a discharge direction; Figure 3: a time course of a pulse with a schematic representation of a counter belonging to this pulse type; Figure 4: a time course of a pulse with a schematic representation of a counter with complete regeneration of this counter; Figure 5: a time course of a sequence of pulses in a discharge direction using two counters and Figure 6: a time course of a sequence of pulses in the charge and discharge direction analogous to the representation in Figure 2 with a representation of the associated counters. Across the various illustrations of the drawing, the same reference symbols are always used for the same process steps, parameters, currents, etc.Without limiting the invention, it is described below only against the background of an application in a battery management system of a battery system designed as a high-voltage system for use in electric vehicles. Currently, control methods for operating battery systems in the charging and discharging directions are always newly developed for each battery system, so that such control methods generally have to be redeveloped accordingly, or at least adapted in the form of programming work, when the elementary storage cells used in the battery system in question are changed to another manufacturer.In order to improve a control method for battery systems in such a way that it allows changes in a current pulse concept in adaptation to the elementary storage cells used in each case and / or a change of the manufacturer of the elementary storage cells and also counteracts a rapidly advancing aging of the storage cells more reliably in a preventative manner, an embodiment of a control method is described below which is implemented with special parameterization as software in a battery management system BMS that can be flexibly adapted to the circumstances of a particular application.A respective battery system is subsequently recorded only based on its performance data and the associated marginal ranges of permissible operation, i.e. in particular a voltage at the poles at permissible currents for a charging and discharging range over specified pulse times in an operating range of the elementary storage cells defined by a minimum and a maximum operating temperature. A key starting point for a control procedure described below is the data of the elementary storage cells for electrical energy and the specifications of each manufacturer of the elementary storage cells used in the respective application, which must be reliably adhered to in order to maintain, in particular, a functional guarantee from the manufacturer over a specified service life of the respective storage cells. These manufacturer guarantees generally applyuntil a limit of 80% residual capacity is reached or the internal resistance of the elementary storage cells doubles. In the exemplary embodiment described below, the following parameters are defined: A current flow I(t) is considered in terms of its magnitude, whereby the flow direction with respect to the battery system distinguishes between charging current and discharging current. A manufacturer of the elementary storage cells used in a battery system provides current pulse maps for three current pulses in the charging and discharging directions for predefined pulse durations t0, t1, and t2. Here, I0 represents a permissible continuous current or I. ContI1 represents the current of a longer continuous pulse, and I2 represents the value of a short-lasting current pulse of maximum magnitude. In addition to I0 < I1 < I2, the pulse times t0 > t1 > t2 assigned to these currents apply. In this exemplary embodiment, these pulse times are defined as t2 = 10 s, t1 = 30 s, and t0 = 3 min. These and other specifications from the cell manufacturer and application-specific settings are arranged in the form of a parameterization interface and stored in a database for the control process for this cell manufacturer. Current pulse maps for t0 = 3 min are defined as constant current maps with I0 = I Contused. A time t1 for the permissible duration of the long current pulse I1 is parameterized with t1 = 30 s. A time t2 for the permissible duration of the short current pulse I2 is parameterized with t2 = 10 s, as shown in Figure 1. The pulses I1 and I2 represent, over the respective pulse durations t1 and t2, permissible increased power outputs or power consumptions of the battery system within the framework of the control with a current pulse concept, which are beyond a permissible continuous load, which is determined by the quantity I0 = I, to improve the performance of the battery system in charging or discharging mode. Contis specified. These permissible increased pulse loads on the battery system and each of its elementary cells within the framework of current pulse control are shown as hatched areas in Figure 1. The characteristic maps are parameterized with an 11 x 1 temperature vector to take into account a dependency on an operating temperature ϑ. Furthermore, the characteristic maps are parameterized with an 11 x 1 SOC vector to take into account a dependency on a state of charge or SOC for short, of the battery system. For simplification while maintaining a sufficiently accurate representation, the state of charge SOC is rasterized in 10% steps from 0% to 100% charge of the battery system, resulting in a total of 11 values. For an even finer representation - not shown here - 5% steps are used, resulting in a total of 21 values ​​in each case, with an otherwise analogous procedure.In the present exemplary embodiment, the following current pulse characteristic maps are generated in parameterized form, each with the support points temperature ϑ and state of charge SOC: ^ a current pulse characteristic map in the charging direction CH for the permissible constant current I0 with the dimensions 11 x 11; ^ a current pulse characteristic map in the charging direction CH for the permissible current in the long current pulse I1 with the dimensions 11 x 11; ^ a current pulse characteristic map in the charging direction CH for the permissible current in the short current pulse I2 with the dimensions 11 x 11; ^ a current pulse characteristic map in the discharging direction DCh for the permissible constant current I0 with the dimensions 11 x 11; ^ a current pulse characteristic map in the discharge direction DCh for the permissible current in the long current pulse I1 with the dimensions 11 x 11, and finally ^ a current pulse characteristic map in the discharge direction DCh for the permissible current in the short current pulse I2 with the dimensions 11 x 11.Thus, a total of six current pulse maps are parameterized for the three predefined currents in the charging and discharging directions, each with the support points temperature ϑ and state of charge SOC, and stored in a database that only needs to be created once for the respective cell manufacturer and the type of elementary storage cell used. Figure 2 shows the temporal progression of a sequence of pulses in the discharging direction DCH of a battery system. The progression of the discharge current I is represented by the curve shown. DCh over time t, at a time a a threshold I DCh,cont exceeded, and up to time c to a threshold I DCh1 From a point in time d, the discharge current oscillates only around the threshold I DCh,cont . This results in a permissible continuous discharge current I DCh,contIn time intervals, longer current pulses and also higher current pulses overlap, the latter between times b and c. This means that in this exemplary embodiment, different pulses can be combined or coupled with one another; a combination parameter K has therefore been set to "1". In addition, the pulses do not have to be run for a full, maximum permissible time length. A long current pulse I1 is therefore also run here for shorter time intervals than t1 = 30 s. An interruption parameter U has therefore been set to "1". In order to measure the load on the battery system due to a respective continuous discharge current I exceeding the permissible continuous discharge current I DCh,contIn order to find the pulsed current flow that exceeds this threshold, a separate current threshold is introduced for each defined pulse current. When this threshold is exceeded, a counter starts running and is only stopped when it falls below this threshold, as described below using Figure 3. The cell data and specifications of a manufacturer also contain, among other things, characteristic values ​​for current pulses and the rest or waiting times that necessarily follow the respective current pulses. For each current pulse, there is therefore a corresponding rest time that depends on the actual length of each current pulse. Normally, the waiting time is at least as long as the length of the respective pulse, but in most cases longer. The energy introduced can be dissipated either by taking the root mean square value or byThe RMS value of the current is converted to the permitted constant current in order to determine the time in which the current actually applied after the current pulse corresponds to the permitted constant current. Alternatively, the energy input into the cell is examined, which leads to heating that is compensated for by heat dissipation or, if necessary, active cooling. In this exemplary embodiment, the following definition is made: For a current pulse of 10 s, a wait of 20 s is required until the energy introduced into a storage cell by the current pulse can be considered to have been dissipated. For a current pulse of 20 s, for example, a wait of 40 s is required; for a current pulse of 30 s, for example, there is a waiting or rest period of 60 s until the next current pulse can be executed. This rest period R is generally independent of the type or form of the respective current pulse. It only depends on the actual current pulse time, i.e. 10 s, 20 s or 30 s duration.However, the times generally vary depending on the cell manufacturer and cell format. For the duration of the short current pulse I2, in this example with t2=10s, a corresponding rest period R2=20s has been parameterized or specified. If a current pulse occurs with a duration between t2 and t1, it is treated as a so-called partial current pulse. For the duration of a partial current pulse I. 21 with e.g. t 21 =20s a corresponding rest time R 21 with R 21=40s. For the duration of the long current pulse I1, defined here as t1=30s, a corresponding rest period R1 with R1=60s is defined to ensure consistency. A current pulse counter or counter C(I1) is provided for the long current pulse I1. The long current pulse I1 may only be run for a maximum time of t1=30s. Figure 3 shows a time profile of a sequence of pulses in the discharge direction using counter C(I1) over time t with a regeneration of counter C(I1). As soon as the flowing current I is higher than the permissible continuous current I Contis, the counter or current pulse counter C(I1) counts upwards, but here from time a. In a database with presets of the control procedure, a parameter R is used as a flag or switch to determine whether the counter or counter C(I1) for the pulse I1 may be counted down over time. If R is set to "1", the current pulse I1 can also be reduced again in the phase in which it is increased. If the current pulse is above the constant or continuous current I Cont=I0, then the counters for the current pulses are increased as described above. If the current falls below the permissible constant current again and the counters C(I1) are at a value above zero, the counter values ​​are reduced again. This process is shown in Fig. 3, e.g., between times b and c. When reducing the counter C(I1), a relationship between the counter for the respective current pulse and a stored waiting time W can be taken into account in a manner not shown here. If, for example, the waiting time is twice as long as the permissible pulse length, then the counter for the current pulse is reduced by a factor of 0.5 during the time in which the current is below the constant current, i.e., the build-up of the counter in 2 s requires 4 s to dissipate accordingly. In the present exemplary embodiment, however, the rise and fall times have been selected to be equal. Therefore, if the current is less than the continuous current ICont=I0, the current pulse counter C(I1) counts down in the same way as it counted up previously. This results in a ramp-shaped curve. Figure 4 also shows a temporal progression of a sequence of pulses in the discharge direction using the counter C(I1) over time t. The same times are used for the rise and fall of the counter, so that the counter curves here also have the same gradients for the rise and fall. If the current falls below the permissible constant current, the counter C(I1) for the current pulse I1 is counted down again. However, the current pulse counter value is only reduced until it reaches 0 s. A reduction is only active if the current pulse counter value is actually greater than 0 s. In Figure 4, the time intervals have been selected so that regeneration of the current pulse counter C(I1) is fully completed several times.When the current pulse counter C(I1) reaches 0, further reduction of its value is stopped. The hatching after the counter decays has been modified in Figure 4, since regeneration is no longer possible at that point. Thus, after the counter C(I1) stops increasing at time b, the current drops below the threshold of the permissible continuous current I. ContAfter just 4 s, at time x, counter C(I1) is balanced. A remaining section, indicated in Figure 4 by a different filling level, therefore has no further influence on the counter. The same case occurs here after the pulse between times c and d at time y. Figure 5 shows a temporal profile of a current flow with a sequence of pulses in the discharge direction, which are significantly stronger than in the example in Figure 3. Thus, in the present embodiment, an additional current pulse counter or counter C(I2) is provided for the short current pulse I2. Analogous to the procedure in Figures 2 - 4, time a represents a starting point for counter C(I1), and counter C(I2) is also started from time b. At time a, the current flow I(t) exceeds the threshold value for a continuous current in the discharge direction, I cont, and only falls below this threshold again at time h. The associated counter C(I1) thus increases linearly up to time h. Over three time periods from time b, the threshold value for a long current pulse in the discharge direction, I1, is also exceeded, whereby this threshold is again undershot at times c, e, and g. Accordingly, the associated counter C(I2) shows a monotonic, terrace-like increase from time b up to time h, while the counter C(I1) continues to rise linearly during these three intervals. The short current pulse I2 may only be run for a maximum time t2 = 10 s. When the counters C(I1), C(I2) are reduced, the current pulse counter values ​​of the current pulses I1 and I2 are reduced. For the current pulse I1, the counter is reduced by the same time increment as the current pulse counter value is increased by 1 s.For current pulse I2, the counter is reduced with a time step size that reflects the ratio between the permissible current pulse counter values ​​of I2 and I1, i.e., by 1 / 3 s in this example. Reduction and incrementation of the counters for the current pulses can be combined dynamically. There is a defined time criterion for the current pulses, which is monitored by a time counter. If a time window is not fully utilized by a current pulse, the permissible current pulse time can be increased again by the counter for a remaining time. The current pulse I2 can run for up to 10 s during permissible interruptions, and the current pulse I1 can also run for up to 30 s during interruptions. A combination of the two current pulses I1 and I2 is also permitted in this example. However, as soon as a permissible time for the current pulse I2 is completely used up, the current pulse I2 is blocked, while the current pulse I1 remains enabled.As soon as a permissible time for current pulse I1 has been completely used up, both current pulses are blocked. At time g, the counter for current pulse I2 reaches the limit of 10 s duration, and the permissible current is limited to the current of current pulse I1. A waiting period W(I2) begins for this counter C(I2). At the following time h, the counter for current pulse I1 also reaches the time mark of 30 s, so that this pulse is blocked from this point on. A waiting period W(I1) also begins for this counter C(I1), and the permissible current is limited to the constant current I. Contlimited. In the embodiment of Figure 5, both current pulse counters have been fully utilized starting from the dash-dotted area. This is followed by a waiting period that varies in length for the current pulses. Only then are the counters reduced again in a ramp-like manner with a respective gradient so that the respective pulses can be controlled again. Furthermore, the proposed control method depends on the shape of the current pulses. Different current pulses can in principle be combined with one another within a permissible current pulse time and a permissible energy input. A combination results in different current pulse shapes, as previously shown, unless a cell manufacturer prohibits such a combination.In the cell manufacturer's specifications and settings, arranged in the form of a parameterization interface, a combination parameter K for the control procedure is used to set whether a combination of current pulses is permitted over the entire time t1, with t1=30s in this case. If a combination parameter K is set to K=1, then the current pulses may be combined over the entire time t1. This means that if K=1, the long current pulse I1 can be run for the time t1, and within this time t1, the short current pulse I2 can also be run for t2, here 10s. If, on the other hand, the combination parameter K is set to K=0, then a combination of the two current pulses I2 and I1 is only permitted within the time period t2 = 10s. As soon as the short current pulse I2 has been run within the time t2 with K=0, both current pulses are prohibited. Then only the constant current I0= I remains. Contpermitted. If the combination parameter K is set to K=0, only the long current pulse I1 can be run for the entire time of t1=30s. In a preferred embodiment of the invention, the current pulses in the charging and discharging directions are considered independent of one another, as shown graphically in Figure 6 using an exemplary embodiment as a possible temporal current profile during the travel of an electrically powered vehicle. Individual time counters and individual consideration of the respective current pulses I1 and I2 are provided for both the discharging direction DCh and the charging direction CH. Charging and discharging currents each lead to heating in the battery system, so that in this exemplary embodiment, a distinction is only made in the amount of heat input, but not in the direction of current flow.This means that the four counters can be combined into just two counters by simple addition, similar to the illustration in Figure 5. From the perspective of heating of the battery system in question, only the pulse height is important, not the flow direction of a current pulse. In other words, there is no need to distinguish between a charging and discharging direction. It is therefore sufficient if counters are updated for the respective pulse sizes. Figure 6 shows a temporal profile of a current flow I(t) with a sequence of pulses which, analogous to the illustration in Figure 2, now run in the charging and discharging direction. The temporal pulse profile shown as an example now passes through the charging and discharging ranges using different pulse heights with interruption of the respective pulses. The coupling factor K and the interruption factor U have therefore each been set to "1".The curve of the discharge current shown over time t results in a threshold I at a point in time a. DCh,cont exceeded, so that a counter C(I1) or Ctr1 for a current pulse I DCh,1 is started. At time b, the discharge current also exceeds a threshold I DCh,1 , which requires the additional start of a counter C(I2) or Ctr2 for a current pulse I DCh,2 A combination of pulses is permissible, i.e. K = 1, as can be seen between times b to c, where a long and a short pulse are combined or run together. At time c, the discharge current falls below the I DCh,1 again, so that the counter for an I DCh,2 – current pulse is stopped again. At a time d the discharge current also falls below the I DCh,contthreshold, so that the counter for an I1 current pulse could be stopped again and a rest period previously determined by the two counters could be counted down; more on this later. Up to a point in time e, the discharge current moves into a charging range and there into the maximum permissible charging current I over long periods. Ch,cont , at a time f the charging current exceeds a threshold I Ch,1 until a time g. Until a time h, the charging current drops to the maximum permissible charging current I over long periods of time. Ch,cont in order to maintain the discharge current I permissible over long periods of time until time i DCh,cont Up to a point in time j, the discharge current remains above the permissible discharge current I DCh,cont , in order to then at time k again set the threshold of the maximum permissible charging current I Ch,contuntil time l. From time m to time n, the current is then again a discharge current above the threshold of the permissible discharge current I DCh,cont.In the present exemplary embodiment, the respective thresholds in the charging and discharging directions of the current flow have been selected to be different in order to reflect the influence of respective heating. Nevertheless, the same counters are used for the longer pulses and the shorter pulses in the charging and discharging directions. The counters Ctr1 and Ctr2 sketched in Figure 6 result from the current curve. Since both pulses in the discharging and charging directions are run significantly below their respective maximum durations and an interruption with U = 1 is also permissible in this exemplary embodiment, there is no enforced limitation of the respective pulses and no waiting time in this example. If R is set to 0, then the current pulse is only reset when a corresponding waiting time is reached - in contrast to the exemplary embodiment in Figure 3. The counter for the waiting time is incremented separately here.This means there are two possibilities for counting down the current pulse: Either the current is below the permissible constant current for so long that the counter for the waiting time reaches the value for the stored waiting time, and then the counter for the current pulse is set to "zero", or the current pulse is counted up until the maximum permitted value for the current pulse is reached. In this case, operation of this current pulse is prohibited and the wait counter must be counted up to the stored value, as shown in Fig. 6. An interruption parameter U specifies whether a respective current pulse must be executed in one piece or over its predetermined time length, or whether this current pulse can be executed in several parts. If the interruption parameter U is set to 0, the current pulses must not be interrupted. If the constant current I0 is exceeded at U=0, the long current pulse I1 becomes active.If the constant current I0= I. Cont If the current value is now exceeded, a further current pulse is only permitted after the corresponding rest period. If the long current pulse I1 is exceeded at U=0, the short current pulse I2 becomes active, i.e. C(I2) > 0. If the long current pulse I1 is now exceeded, a further short current pulse I2 is only permitted after the corresponding rest period. If, on the other hand, the interruption parameter is set to U=1, then an interruption of the current pulse is permitted. This means that it is possible for the current to fall below the current criterion for the current pulse, the associated counter is interrupted and thus the value of the respective counter is maintained. Subsequently, the current may again exceed the current criterion for the current pulse and the associated counter then continues to count. If the current pulse is interrupted at U=1, the associated counter continues to count as the waiting time counter. If the counter Ctr Wfor the waiting time W reaches the corresponding value for the rest time R, then the counters Ctr W for the current pulses C(I1) and C(I2) and waiting time W are reset. Furthermore, in one embodiment, the following regulations are implemented in the method: ^If a current pulse has been run for less than or equal to the time period t2 with t2=10s, then the rest time R is set to the value R2. This means that if no further pulse is run for the rest time R2 of, for example, 40s, then the counters for the current pulses C(I1) and C(I2) and the counter Ctr W for the waiting time is set to 0. ^If a current pulse is applied for less than or equal to a time period t 21 with here t 21 =20s, but more than t2 was driven, then the rest time R is set to the value R 12 This means that if the rest period R 21 from e.g. R 21=40s no further pulse is run, then the counters for the current pulses C(I1) and C(I2) and waiting time counter Ctr W set to 0. ^If a current pulse for less than or equal to t1 with t1=30s but more than t 21 with t 21 =20s), then the rest time R is set to the value R1. This means that if no further pulse is run for the rest time R1 of e.g. R1=60s, then the counters for the current pulses C(I1) and C(I2) and the waiting time counter Ctr Wset to 0. ^As soon as the pulse counter for the long current pulse has reached C(I1) = t1 with t1 = 30 s during a permissible interruption, i.e. U = 1, a waiting time of R1 with R1 = 60 s must be waited for until the next current pulse is permitted, regardless of the previous waiting time. Reference symbol list DCh Current flow towards discharging the battery system C(I1) Counter / counter for the flow duration of the long current pulse I1 / Crt1 C(I2) Counter / counter for the flow duration of the short current pulse I2 / Crt2 Ch Current flow towards charging the battery system CtrW Counter or counter for the waiting time I Cont Threshold of a max. permissible constant current, I cont =I0I1Threshold of a long current pulse I2Threshold of a short current pulse I 21 Threshold of a partial current pulse K Combination parameter as flag R Countdown parameter as flag R1 Rest time of the short current pulse I1, R1= 80s R2 Rest time of the short current pulse I2, R2= 40s R 21 Rest time of the partial current pulse I 21 , R 21=60s SOC State of charge of the battery system, (State of charge) t0 duration of the permissible continuous current I0, t0= 3 min t1 duration of the long current pulse I1, t1= 30 s t2 duration of the short current pulse I2, t2= 10 s 21 temporal length of a partial current pulse I 21, t 21 = 20s ϑ Temperature of the battery system U Interruption parameter as a flag W Value of a waiting time as a forced rest time of a respective current pulse a,b,c,d,e,f,g,h,i,j,k,l,m,n Times of exceeding or falling below a threshold x,y Times of balancing a counter

Claims

Claims 1. Control method for a battery system, which is constructed in particular for use in electric vehicles from a plurality of elementary storage cells, which are permanently connected to one another in series and / or in parallel to achieve predetermined electrical connection properties defined by an operating voltage and a maximum current, characterized in that the control method is set accordingly to a respective battery system with the cell types provided therein, their designs and their cell chemistry, with a current (I) above a permissible constant current (I cont) is applied and the control takes place on the basis of an estimate of a temperature change in the storage cells.

2. Control method according to the preceding claim, characterized in that parameters for individual characteristics of the current pulse concept as well as dependencies on a respective application are used in the algorithm of the control method.

3. Control method according to the preceding claim, characterized in that parameters for different pulse lengths of different current pulses (I cont , I1, I2) are used.

4. Control method according to one of the preceding claims, characterized in that from a database connected to the algorithm of the control method, current pulse characteristic maps relating to the cell types used in the battery system are read out over temperature (ϑ) and a state of charge (SOC).

5. Control method according to one of the preceding Claims, characterized in that waiting times (W) and / or rest times (R i ) by a counter (Ctr W) are read out from the database and adjusted as a function of a respective current pulse.

6. Control method according to one of the preceding claims, characterized in that a dependence of a temperature change in the memory cells on a type or form of a current pulse is parameterized.

7. Control method according to the preceding claim, characterized in that the different current pulses are provided with an indication by a combination parameter (K) as to whether different types of current pulses may be used in combination with one another.

8. Control method according to one of the preceding claims, characterized in that a counter (C) is used to monitor the respective current pulses and associated waiting times, so that after utilization of a pulse, a permissible constant current (I Cont) is regulated until the next current pulse of a respective type or form is allowed again.

9. Control method according to one of the preceding claims, characterized in that it is determined in the database whether an interruption (U) of a respective current pulse is allowed.

10. Control method according to one of the preceding claims, characterized in that it is determined in the database via a parameter (R) as a flag whether counters for the pulses may be counted down over time (t).

11. Control method according to the preceding claim, characterized in that the respective counter is Occurrence of corresponding current pulses with associated values ​​for additional counter values ​​while counting down, the total counts up further.

12. Control method according to one of the preceding claims, characterized in that a current flow based on heating of the respective battery system is determined for each flow direction of the current or in the charging and / or discharging direction of a pulse height (I Cont , I1, I2) with respective threshold values.

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