WO2008034752A2

WO2008034752A2 - Method for determining an operating state of an energy accumulator

Info

Publication number: WO2008034752A2
Application number: PCT/EP2007/059619
Authority: WO
Inventors: Hans-Michael Graf; Alexander Hahn
Original assignee: Continental Automotive Gmbh
Priority date: 2006-09-20
Filing date: 2007-09-13
Publication date: 2008-03-27
Also published as: WO2008034752A3; DE102006044297A1

Abstract

The invention relates to a method for determining an operating state of an energy accumulator. According to said method, an idle time phase caused, for example, by a change-over of the energy accumulator, is registered. After entering into a phase following a movement of the vehicle, the energy accumulator is discharged, and measuring values recorded.

Description

description

Method for determining an operating state of an energy store

The invention relates to a method for determining the operating state of an electrical energy store in a vehicle. As electrical energy storage ^{beispielswei ¬} se a lead-acid battery, colloquially referred to as a motor vehicle battery, understood.

In modern vehicles, such as motor vehicles such as passenger cars, trucks or in water or air-powered means of transportation, the use of an electrical energy storage for supplying the vehicle with electric current is known.

In modern vehicles, it is intended to provide measured values at the electrical energy store continuously and also at specific time intervals and to evaluate them. In this case, storage of the measured values is usually also provided. The measurement reading and evaluation serves inter alia a determination of the current and the future, i. predicted, state of charge and a diagnosis of errors.

When replacing the energy storage device in a vehicle there is the problem that there is no measured value history for the exchanged energy storage device and thus no information about the operating state of the newly used energy storage ^device . The operating state of the energy store is in particular its state of charge (state of charge) and / or its "state of health" (state of health) understood.

A similar problem also arises when exchanging or resetting the control unit responsible for recording and evaluating the measured values. In the following, reference is made to the described replacement of the energy store as well as to the control unit responsible for the recording and evaluation of the measured values and a resetting of the same with the term "voltage-free time phase". The term "de-energized" means a failure of the electrical voltage of the energy storage.

The object of the invention is to provide an at least improved ^method and a device for determining the operating state of an energy store in a vehicle after a voltage-free time phase.

The object is achieved by a method having the features of patent claim 1. The object is further achieved by a control device having the features of patent claim 8 and by a vehicle having the features of patent claim 9.

According to the invention, a method for determining an operating state for an energy store of a vehicle is provided, in which a voltage-free time phase is registered. After a detected dead time phase occurs after entering a movement of the vehicle - i. After a charging phase, that is to say charging of the energy store by a generator installed in the vehicle, following a run, a discharge of the energy store is performed with the taking of measured values.

A significant advantage of the method according to the invention is the fact that a discharge only after the parking of the vehicle, that is, after a movement of the vehicle takes place. It is not essential to the invention, that the vehicle is actually moved, it is essential We ^¬ sentlichen that the discharge is carried out only after a charging phase. This measure ensures advantageous in ^¬ manner that a necessary discharge at least until after a charge phase - during operation of the motor vehicle - and thus at least not a first commissioning of the internal combustion engine endangered.

A further significant advantage of the method according to the invention is that it uses the tail for the electrical discharge of the energy store. This caster is understood to mean a continued operation of electrical consumers in the motor vehicle after stopping the internal combustion engine or after the motor vehicle has been switched off. This operation of electrical consumers, such. As fans, control devices (eg, engine control, transmission control, vehicle suspension control and damping control), extends over several minutes after stopping the motor vehicle. The method according to the invention makes use of a consumption of electrical energy for a defined discharge of the energy store in the case of ^simultaneous recording of measured values, such as, for example, energy. B. discharge current and the voltage applied to the poles of the energy storage during discharge.

Further advantages and embodiments of the invention are the subject of the dependent claims.

According to an advantageous embodiment of the invention, a so-called "resting phase" is provided with a lower or no load of the energy store after completion of the discharge, in which the removal of measured values, in particular a rest voltage is continued. In this following the discharge resting phase an accurate determination of the state of charge is possible.

A further advantageous embodiment of the invention provides for a query of the vehicle operator, whether a discharge should be performed. The vehicle operator is thus given the opportunity to cancel the discharge ^¬ process in an advantageous manner. Such aborting by the vehicle operator would prove advantageous, for example, if the vehicle operator were aware of such a low one Charge state of the energy storage is that a later on ^¬ let the engine is no longer possible he seems ^¬ .

The measured values obtained during the discharge relate in particular to a discharge current intensity and / or an electrical voltage tapped between the poles of the energy store, e.g. Standby voltage or discharge voltage. Both the measured values and their time course are recorded.

An embodiment with further advantages and Ausgestal ^¬ tions of the invention will be explained in more detail below with reference to the drawing. It is understood that the training shown leadership of the invention is merely exemplary in nature and a detailed presentation is available ^¬ not restrictive to ver.

The single FIGURE shows a schematic flow diagram, which includes a discharge of an energy storage in a vehicle.

The energy storage of the vehicle is for example a lead-acid battery, which is monitored by a control unit. Such a control device is ver ^¬ responsible among other things for a Ü monitoring an operating state of the energy storage. Components of this operating condition are at ^¬ play, the energy content or SOC (state of charge), performance or SOF (State of Function) and battery-riealter or SOH (State of Health).

The control unit uses, for example, a model of the energy storage unit used in the vehicle, by means of which ak ^¬ tual and recorded measurements - also called Messwerthis- torie - a particular operating state may be assigned. A continuous determination of the Betriebszu ^¬ article and a provision of an optimal charging voltage by a likewise present in the vehicle generator warranty provide a consistently optimal operating state of the energy storage.

In a first state 1 it is now assumed that a de-energized phase, for example as a result of a Wech ^¬ sels of energy storage, has taken place. The first to ^¬ stand 1 can, moreover, also during the movement of the vehicle or at a point in time lying in front set, for example, by a failure. Reasons for this are, for example, a failure of a controller or the

On-board electronics, a voltage drop in the electrical system due to excessive load current or contact problems between the control unit for recording the measured data and the electrical system.

A dead phase thus means that a mapping of the in-vehicle energy storage device to the measuring ^¬ history can no longer be guaranteed.

By an active discharging of the energy store measurement can be taken, which allow to determine the current operating state of the battery ^¬ values. By means of this active discharge of the battery, however, the state of charge of the energy store is jeopardized and in the worst case can lead to the vehicle not being able to start after this active discharge.

Therefore, the method of the invention provides an active Entla ^¬ dung after a previous movement of the vehicle correspondingly to the second state 2 before. The state 2 is characterized by an operation of the electrical system with increased voltage.

For a subsequent third state 3 is assumed to stop the vehicle. This is similar to conventional vehicles forth ^¬ a stopping of the engine, so a to a first starting and a first drive 2 is beaten third state. 3 In a fourth decision ^step 4, it is determined on the basis of stored information whether, as a result of the voltage-free phase which has taken place, measured values ascertained hitherto for re-learning the operating state can be used. If this is the case, according to a decision branch "yes", which leads to the right in the drawing and is not provided with a reference character, then the procedure is ended at this point. The measured values - that is, the battery load recorded within a driving profile - are sufficient in this case to assign the current operating state of the energy store to the model of the energy store. The said ^decision branch »yes« leads to a conventional behavior of the vehicle.

Were able to preserve the existing measurements in accordance with the decision ^¬ branch n "No," not a relearning - that is, allocation of the current operating state to the model of the Energiespei ^¬ Chers - are used, the decision step 4 results in the following fifth state. 5

In the fifth state 5, the vehicle is stopped or abge ^¬ presents. At the same time as the vehicle is parked, in a sixth decision step 6, an operator feedback question occurs in which the vehicle operator can be warned before the discharge is activated. The vehicle operator is given the opportunity to cancel the following discharge. Alternatively or additionally, in this decision step, a message or warning to the vehicle operator is provided if the type of energy storage used is not recognized.

In the sixth decision step 6 »Cancellation by the vehicle operator? «Is displayed a possible cancellation by the vehicle operator. In a decision branch n, the vehicle operator has not canceled the following unloading operation, so that the procedure changes to the following seventh process step 7. In one in the drawing If the vehicle operator has aborted the following unloading procedure on the right-hand, non-referenced decision branch, the method is ended at this point. The named decision branch leads to a conventional behavior of the vehicle.

In the seventh step 7, an overrun of the driving ^¬ zeugs is initiated. In an eighth step 8 occurring at the same time, before or on it, the discharging of the energy store takes place.

This discharge or active discharge consists in a preferred embodiment of a current discharge of about 10 to 25 amps (A) with an assumed battery capacity of 100 ampere hours (Ah) for a period of about 5 to 10 minutes. The discharge current intensity is preferably kept constant. For this Konstantstromentladung while consumers of the wake are used, for example Lüf ^¬ ter, controllers, etc.

The discharge amount is at least 1% of the Batteriekapa ^¬ capacity. The discharge current during the constant current discharge is set so that it ideally varies by less than 10% around the mean. During the discharge of the time course of measured values such as the electrical voltage between the poles of the energy storage and the height of the discharge current is recorded and stored in a suitable manner.

After performing the discharge in accordance with the eighth step 8, a ninth state 9, in which a lower or no load of the energy storage is provided. The ninth state 9 is therefore also referred to as rest phase. For example, a low load corresponds to a discharge current of typically less than 200 mA. The rest ^¬ phase has a duration of at least 5 to about 20 minutes. During this rest phase, essentially the electrical voltage between the two poles of the energy Memory evaluated. The tapped in the resting phase voltage corresponds to the above-mentioned rest voltage.

The readings in the eighth and ninth phase 8.9 enable quick and accurate detection operation ^¬ state, in particular charge state if the measured values in ^¬ to stand 4 were unsuitable to do so.

An advantage of this method is that an active discharge is not caused after each stop of the vehicle, but only after a de-energized phase. The de-energized phase is registered and stored by a control unit or battery ^monitor . A reset of the corresponding control unit is also evaluated as a voltage-free phase.

Another advantage is to avoid excessive battery discharge, since an active discharge takes place only after the first time the vehicle is parked.

The optional user consultation ensures zusätzli ^¬ che safety by a possible intervention by the vehicle operator, who can stop an additional active discharge, for example, in the knowledge of a very low state of charge. Such user query can be omitted, among other reasons from practi ^¬ reasons because they exceed any technical expertise of the vehicle operator could ^¬ te.

Furthermore, the time of discharge advantageously ensures a starting capability, which is limited only after the first successful start by an active discharge.

The discharge to be set differs from the usual caster in terms of discharge amount and constancy of Entla ^¬ tion current, but is advantageously integrated into the caster. An exemplary wake with a time course of the current of 20 A for one minute, followed by 5A for 10 minutes and 2 A for another 20 minutes, for example, modified so that a time course of Entla ^¬ dungsstromes from a ten-minute period with a Entla ¬ ^¬ dung current of 20 a, followed by a five minute period of 5 a and another 20 minutes with 2 sets a.

For the active discharge so existing consumers are used, which are involved in a conventional caster. Advantageously, this saves the use of additional components such as active discharge resistors.

Claims

claims

1. A method for determining an operating state of an energy store in a vehicle, comprising the following method steps:

- Registration of a dead time phase

- After entering a following a movement of the vehicle caster is carried out a discharge of the energy storage with taking measurements.

2. Method according to claim 1, characterized in that the discharge current intensity and / or the voltage between the poles of the energy store and / or the temperature of the energy store are recorded as measured values.

3. The method according to any one of claims 1 or 2, characterized in that the time course of the measured values is recorded.

4. The method according to any one of the preceding claims, characterized in that after completion of the discharge, a rest phase is initiated with a lower or no load of the energy storage with a continued removal of measured values.

5. The method according to any one of the preceding claims, characterized in that before the discharge of the energy storage a query of the vehicle operator is provided

6. The method according to any one of the preceding claims, characterized in that for discharging the energy storage at least partially involved in the wake electric energy consumers are involved.

7. The method according to any one of the preceding claims, characterized that a discharge amount of the discharge is at least 0.5 Pro ^¬ center, preferably one percent of the capacity of the Energiespei ^¬ is Chers.

8. Control device for a vehicle for determining an operating state of an energy storage device with means for re ^¬ registration of a voltage-free time phase and means for performing a discharge of the energy storage after entering a following a movement of the vehicle caster taking readings.

9. vehicle with a control device mounted therein according to claim 8.