KR20080033237A - Method for identifying preset values of an electric accumulator - Google Patents

Abstract

The invention relates to a method for identifying preset values of an electric accumulator, for example of a battery in a vehicle, according to which method various parameters are determined. These parameters are rapidly adaptable parameters that can be adapted within seconds or minutes and slowly adaptable parameters that are adapted within hours or days. One of these slowly adaptable parameters is the battery capacity. Since the rapidly adaptable parameters correlate with the slowly adaptable parameters, the latter, especially the battery capacity, is inferred from the rapidly adaptable parameters while taking into consideration settable rating routines and incorrect ratings. The determined parameters are compared with stored parameters, thereby allowing to identify the inserted battery type.

Description

METHOD FOR IDENTIFYING PRESET VALUES OF AN ELECTRIC ACCUMULATOR}

The present invention relates to a method for recognizing the presettable parameters of an electrical storage battery having the features of claim 1. In particular, variables of the electric energy accumulator or charger for an automobile are detected, and the preset parameters include the performance, storage capacity or battery type of the electric accumulator.

In order to monitor the performance and / or storage capacity of electrical energy accumulators within the scope of automotive electrical systems, such as electrical energy management systems, for certain parts, a one-off method of using a priori information by the energy accumulator used is used. This method is described for example in DE 199 59 019. Such information about the energy storage battery used utilizes nominal capacity or cold starting current, for example, to detect performance and storage properties, which are the sought parameters.

For a vehicle type, for example, where different battery parameters are taken into account depending on its driving force or on-board consumer, the preferential data of the battery state identification should be retained in the installation or replacement of the energy storage battery. This can occur through the corresponding coding in the shop, but is not feasible when the battery is replaced by the end purchaser. Also errors in coding cannot be ruled out. The model-based adaptation method for battery state recognition offers another possibility of adapting itself to parameters related to performance or storage, such as through continuous measurement of the current, voltage and temperature of the energy storage battery. This method is allocated to the circulation of sufficient automotive electrical system dynamics and energy accumulators for the rapid adaptation of the desired parameters, since active interference to the automotive electrical system is not allowed by the car manufacturer or is too complex and expensive. Because.

However, sufficient automotive electrical system dynamics are not always provided, for example during highway driving and very frequent cycling, since the dynamics reduce battery life. Therefore, depending on the situation, it may take days to several weeks until the battery state recognizer adapts to the parameters of the replaced battery. This is particularly true of battery capacity where a charge stroke / discharge stroke of 20-30% or more of nominal capacity is required for its adaptation by the current method. Another aspect is that, in general, not all the parameters associated with performance and storage can be adapted, otherwise the method can be very complex, and the measurement variables current, voltage, temperature are not sufficient for this or Or, because the energy storage battery must be operated at an operating point that does not normally occur in an automobile, such as an overcharged or undercharged state.

The method according to the invention for recognizing preset variables of an electric battery, having the features of claim 1, enables a quick recognition of the battery type and the parameters of the battery type and of the parameters involved in the detection of performance and / or storage. Has the advantage of performing adaptation. It is particularly suitable for use in electric accumulators, such as lead batteries, in motor vehicle electrical systems, and continuous measurement of current, voltage and temperature is carried out without the regulation of the battery type or battery type or the active stimulation of the electrical system.

In particular, it is desirable that the type and parameters of the electrical energy storage battery can be detected more quickly, even when compared to known methods based on the model. The method according to the invention thus allows certain information about the performance and storage of the already replaced energy storage battery within minutes of the first operating step. This is particularly important for safety critical applications such as X-Bi-Wire-applications, so whether the exchanged energy storage battery or the energy exchanged for this application is acceptable and whether the required output or storage can be fundamental. It is recognized as soon as possible.

Said advantages are realized by using a method of detecting various parameters in order to recognize preset parameters of an electric storage battery, for example a battery of an automobile. The parameters are fast adaptable parameters that are adapted within seconds or minutes and slow adaptable parameters that are adapted within hours or days. One such slowly adaptable parameter is battery capacity. Since fast adaptable parameters are associated with slow adaptable parameters, slow adaptable parameters, in particular battery capacity, are deduced from fast adaptable parameters under consideration of preset evaluation routines and evaluation errors. By comparison of the detected parameters with the stored parameters, the type of battery mounted can be recognized.

Other advantages of the invention are realized by the method described in the dependent claims. In this case, in particular, the method according to the invention will mainly recognize whether the energy storage battery has been replaced or if the aged battery has been disconnected from the electrical system for other purposes only, ie for recharging in the charging device. It is also desirable when possible.

As a fast adaptable parameter, the RC-member's time constant or the ohmic internal resistance of the electric battery is selected, which has a small time constant consisting of the preset resistance and capacity of the electric battery. As a slowly adaptable parameter, for example, an alternative capacity of the electric storage battery is selected.

From the comparison of the fast adaptable and slow adaptable parameters with the stored parameters, performance and / or storage can be inferred reliably or infer whether the energy accumulator is an allowed energy accumulator or whether the exchange of batteries is carried out. do.

Particularly from the adapted or unadapted parameters, an interval value is formed which is compared with the stored parameters for the recognition of the preset variables, from which the preset variable, in particular the battery type, is inferred. The interval value may be formed according to the error square or absolute value of the preset parameter. The relative error square of the preset parameter or parameter set can be detected according to the actual accuracy of the evaluated parameter and its importance for a particular battery type, the importance being taken into account by the weighting factor. It is desirable for a fast adaptable parameter to contribute more to the interval value than a slow adaptable parameter whose error variance remains at a high level for a long time. Preferably, the parameters are weighted for their importance for differentiating between different battery types and the parameters with the largest relative dispersion are most heavily weighted for the battery type, in particular for the battery type and vice versa.

Embodiments of the invention are shown in the drawings and described in more detail in the detailed description.

1 shows an equivalent circuit diagram of a lead storage battery.

FIG. 2 shows the important parts of the invention of an apparatus for recognizing preset parameters of an electric storage battery.

3 is a flowchart with substantial method steps.

The present invention relates to the fact that during normal electrical system excitation, certain parameters of relatively fast adaptable (seconds to minutes) electrical energy accumulators, such as lead acid batteries, are correlated with slowly adaptable parameters (hours to days), such as battery capacity, After a transient phenomenon of rapidly adaptable parameters, a slowly adaptable parameter can be inferred.

The parameters or variables of an electric storage battery, such as a lead battery and a lead storage battery, according to the invention are shown in FIG.

The equivalent circuit diagram of the lead acid battery shows the following correlation:

Operating Variables:

I _BATT = battery current (<0 for discharge)

U _BATT = battery voltage

T _BATT = battery temperature

State variables:

U _CO = no-load voltage

U _K = concentration polarization

U _DP = through polarization of the positive electrode

U _DN = through polarization of the negative electrode

parameter:

R _i = Ohm internal resistance (capacitor grid + acid)

C _o = Alternative capacity of the battery

R _k , C _k = resistance and capacity of acid diffusion

R _Dp , C _Dp = resistance and capacitance of the bilayer of the positive electrode

R _Dn , C _Dn = resistance and capacitance of the double layer of negative electrode

Replacement of battery capacity (C _o) is in the range of 150000F 350000F to a conventional case of start-up battery. That is, in order to be able to determine the capacity (C _o ) from the measurable voltage change at the battery terminal, a large discharge or charge increase of 20 to 30% of the nominal capacity is required, which, in an automotive-electric system, in some cases, several hours Or occurs only for a few days' time. The capacity of acid diffusion (C _k ) and C _Dp or C _Dn of the electrical double layer between the electrode and the electrolyte are at least scalable for a new battery having a replacement capacity (C _o ). These, together with the corresponding parallel resistances (R _k or R _Dp , R _Dn ), form an RC-member with a time constant in the range of a few seconds to less than a few minutes, so that C _k at sufficiently high charge / discharge currents And C _Dp , C _DnA can be clearly adapted faster than the replacement dose (C _o ). The ohmic internal resistance (R _i ) also provides information about the replacement capacity, at least for new batteries and when associated with a fixed state of charge and temperature, because the internal resistance decreases with increasing battery capacity. to be.

From this problem a method according to the invention is presented, the practical steps of which are shown in Fig. 3, from which the equation described below is presented: The method first of all is a parameter of all new new batteries, which are considered for a particular vehicle. The set starts from being stored in one non-volatile memory ( p _Batt1 , p _Batt2 , .., p _Battn ). The adaptation of the parameter is symbolized in step S1. To further recognize whether a battery exchange has occurred or whether the battery has only been disconnected, the last adapted battery parameters are stored non-volatile ( p _Batt0 ). It is also assumed that the parameter refers to a preset fixed value of the temperature and state of charge of the energy storage battery (eg Tbatt = 25 ° C., SOC = 100%), so for new batteries the parameters only follow the battery type. The parameters are divided into adapted _{and unadapted} parameters: p _Batt ^T = [ p _{Batt, ad} ^T p _{Batt, noad} ^T ].

In order to recognize the battery type or the battery type that the stored parameter set ( p _Batt0 , p _Batt2 , .., p _Battn ) most quickly corresponds to the parameter set ( p _Batt ) of the battery actually installed, the following "spacing value" Used for adapted parameters:

D ² _o..n = ∑gew _i * [(p _{i, Batt, ad} -p _{i, Batt0..n, ad} ) / p _{i, Batt0..n, ad} ] ²

           ^{i = 1 ... m}

Optionally, for example, an absolute value can also be used for the error square. Each error square of an individual parameter is _weighted by the factor gew _{i = 1..m} , depending on the actual accuracy of the parameter evaluated and its importance for a particular battery type, individually for each of the m parameters of the parameter set. . If a parameter is evaluated, for example by a Kalman-filter, the filter provides its error variance (P _{p1..m, Batt} ) for each parameter, so the following equation is provided for the weighting coefficient:

gew _{A, i = 1..m} = min (1.0, P _{Schwelle, 1..m} / P _{p1..m, Batt} )

That is, the reduced evaluation error variance or increased accuracy of the parameter increases the weight of the error belonging to it until the weight is limited to a maximum value of 1 in the case of a preset variance threshold (P _{Schwelle, 1..m} ).

Thus, a fast adaptable parameter may contribute more to the interval value than a slow adaptable parameter whose error variance remains at a high level for a long time. In addition, the parameters are weighted for their importance for differentiating battery types, that is, the parameter with the largest relative variance is weighted most heavily for the battery type and vice versa:

gew _{B , i = 1..m} = min (1.0,1 / (n + 1) * ∑ [(p _{i , Batt , j, ad} -p _{i , Batt , ad , mittel} ) / p _{i , Batt , ad , mittel} ] ² )

j = 0..n

in this case,

p _{i, Batt, ad, mittel} = 1 / (n + 1) * ∑p _{i, Batt, j, ad}

j = 0..n

In summary, the "interval value" is:

D ² _o..n = ∑gew _i * [(p _{i, Batt, ad} -p _{i, Batt0..n, ad} ) / p _{i, Batt0..n, ad} ] ²

i = 1..m

Presented as

in this case,

gew _i = gew _{A, i} * gew _{B, i}

gew _{A, i} = min (1.0, P _{Schwelle, i} / P _{p, i, Batt} )

gew _{B , i} = min (1.0,1 / (n + 1) * ∑ [(p _{i , Batt , j, ad} -p _{i , Batt , ad , mittel} ) / p _{i , Batt , ad , mittel} ] ² )

j = 0..n

p _{i, Batt, ad, mittel} = 1 / (n + 1) * ∑p _{i, Batt, j, ad}

j = 0..n

After the fast adaptable parameter is over-recognized and the benefit is recognized in step S2, then in step S3 it is selected next in the evaluated parameter set, through minimization of the interval values, and is not slowly adaptable or not adaptable. The parameters may be replaced with parameters of the selected parameter set. In addition, it may be determined whether a battery exchange has been provided and in some cases whether a battery which has not been provided for the purpose of use has been replaced when the interval for the stored parameter set is very large:

k = Index (min (D ² _0..n ))

Case 1:

In step S4, it is checked whether min (D ² _0..n ) <D ² _max .

If this is not the case,

min (D ² _0..n )> D ² _max applies:

⇒ It is recognized in step S5 that an unsolicited battery, ie an unsolicited battery, has been used.

Case 2:

If YES is determined in step S4, it is checked whether k &gt; 0 in step S6.

If this is not the case,

k = 0 and min (D ² _0..n ) ≤ D ² _max apply:

⇒ The battery is not replaced (step S7)

Case 3:

If YES is determined in steps S4 and S6,

k = 1..n and min (D ² _0..n ) ≤ D ² _max apply:

⇒ The battery type is clearly recognized (step S8)

If an inappropriate parameter set is detected as in Case 1, the prediction of the performance and / or storage of the energy storage battery, for example as described in DE 103 01 823 A or DE 103 28 721 A, based on fast adaptable parameters By the person, basic information on the availability for that purpose can be presented.

The method of the invention according to the independent claims, comprising preferred variants, is carried out by means of an evaluation device, in particular representing a control device such as a computer device or a battery control device or an electrical system control device and including memory means in addition to the appropriate processors. . Variables necessary for the execution of the method are measured by appropriate means, such as sensors, and provided to the evaluation device, and in some cases processed by the evaluation device after processing. 2 shows the means of the evaluation apparatus according to the invention. These are the processor P on which the method according to the invention is carried out, one or a plurality of memories SP in which initial values are stored and accessible to the processor P. In-memory measurements can also be conveyed in memory. Measurements, such as I _Batt = battery current (<0 for discharge), U _BATT = battery voltage and T _BATT = battery temperature are measured by suitable means, in particular sensors, and provided to the processor P. The A mark may indicate the detected charging state or the battery type.

Claims (18)

A method for recognizing presettable parameters of an electrical storage battery, The fast adaptable parameter of the electric battery and the slow adaptable parameter of the electric battery are detected, the slow adaptable parameter is detected from the fast adaptable parameter, and the detected parameter is compared with the stored parameter. Method for recognizing possible variables. The method of claim 1, wherein the detection of the parameter is performed when the battery is under normal or normal load. 3. The preset of an electric storage battery according to claim 1 or 2, wherein the fast adaptable parameter is a parameter adapted in a few seconds to several minutes, and the slow adaptable parameter is a parameter in which the adaptation takes several hours to several days. Method for recognizing possible variables. 4. A method according to claim 1, 2 or 3, wherein after a transient process of fast adaptable parameters, slowly adaptable parameters are inferred therefrom. The method according to claim 1, wherein the parameter sets are stored in one non-volatile memory. 6. 6. An electric machine according to any one of claims 1 to 5, wherein the battery in the motor vehicle is provided as an electric accumulator and the parameter sets of all batteries considered for a particular motor vehicle are stored in one non-volatile memory. Method for recognizing the presettable parameters of the battery. The fast adaptable parameter according to any one of claims 1 to 6, wherein an ohmic internal resistance of an RC-member or an electric battery having a small time constant composed of at least the predetermined resistances and capacities of the electric battery is selected. A method for recognizing presettable parameters of an electric accumulator. 8. A method according to any one of the preceding claims, wherein at least a replacement capacity of the electrical battery is selected as the slowly adaptable parameter. 9. The pre-set of the electric storage battery according to any one of claims 1 to 8, wherein the performance and / or storage property are inferred from the comparison of the quickly and slowly adaptable parameters with the stored parameters. Method for recognizing variables. 10. The method according to any one of the preceding claims, characterized in that from the comparison of the fast adaptable and slow adaptable parameters with the stored parameters, it is inferred whether the energy accumulator is an allowed energy accumulator. Method for recognizing presettable parameters of an electric storage battery. The preconfigurable electric battery according to any one of claims 1 to 10, wherein it is deduced whether or not the battery is replaced from a comparison of the fast adaptable and slow adaptable parameters with the stored parameters. Method for recognizing variables. 12. The method according to any one of the preceding claims, wherein from the adapted or unadapted parameters, an interval value is formed which is compared with the stored parameters for the recognition of the presettable variables, from which the preset result is possible. Variable, in particular the type of battery, is deduced. 13. The method of claim 12, wherein the interval value is formed according to an error square or an absolute value of the preset parameter. 14. A method according to claim 12 or 13, characterized in that the relative error squares of the preset parameters or parameter sets are detected according to the actual accuracy of the evaluated parameters and the importance of the evaluated parameters for a particular battery type. Method for recognizing presettable parameters of an electric storage battery. 15. The method of claim 14, wherein importance is considered by weighting factors. The dictionary of any of claims 12 to 15, wherein the fast adaptable parameter contributes more to the spacing value than the slow adaptable parameter whose error variance remains at a high level for a long time. Method for recognizing set variables. 17. The method according to any one of claims 12 to 16, wherein the parameters are weighted for their importance for distinguishing between different battery types and the parameter with the largest relative dispersion is weighted most for battery types, in particular for battery types. And vice versa, a method for recognizing preset variables of an electric storage battery. 18. An apparatus for executing at least one method according to any one of claims 1 to 17, The device comprises computer means and memory means, in particular a part of a control device.

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