CN113682197A

CN113682197A - Charging device, motor vehicle and method for charging an energy store of a motor vehicle

Info

Publication number: CN113682197A
Application number: CN202110417867.7A
Authority: CN
Inventors: T.斯蒂乔夫斯基; R.波恩格拉伯
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2020-05-19
Filing date: 2021-04-19
Publication date: 2021-11-23
Also published as: DE102020206258A1

Abstract

The invention relates to a charging device (3) having a charger (5) for charging an energy store (2) of a motor vehicle (1), wherein the charging device (3) has a control device (4) which is provided for specifying a charging process of the energy store (2) to be carried out by the charger (5) in the form of a full charging process (V) or a partial charging process (T), wherein the charger (5) charges the energy store (2) to a state of charge of 100% in the full charging process (V) and the charger (5) charges the energy store (2) to a state of charge of a value below 100% in the partial charging process (T), wherein, for recalibrating the state of charge of the energy store (2), the charging device (3) is also configured such that, after a specified number of successive partial charging processes (T), the controller (4) specifies at least one full-charge process (V). The invention further relates to a motor vehicle (1) having such a charging device (3) and to a method for charging an energy store (2) of a motor vehicle (1).

Description

Charging device, motor vehicle and method for charging an energy store of a motor vehicle

Technical Field

The invention relates to a charging device having a charger for charging an energy store of a motor vehicle, to a motor vehicle having such a charging device, and to a method for charging an energy store of a motor vehicle.

Background

DE 102009036943 a1 discloses charging an energy store of a motor vehicle in a fully charged mode or a parked charging mode. The full charge mode or the parking charge mode is set by the circuit. In the park charge mode, the accumulator is not fully charged. The reduced state of charge in the park charge mode extends the useful life of the accumulator.

The inventors have recognized that in the event of a plurality of consecutive state of charge charging processes in which the energy store is charged to a value below 100%, an incorrect determination of the operating capacity and therefore of the state of charge may result. After all, the State of Charge (SOC) is defined as the quotient of the remaining capacity and the operating capacity after the last full Charge. As the accumulator is used, the accumulator ages and the operating capacity decreases. However, if the state of charge is not fully charged but only partially charged to a value below 100%, this aging cannot be taken into account and the state of charge is erroneously calculated. This calculation can still provide a good approximation for a single partial charge, since the operating capacity of the accumulator generally drops significantly after a large number of charge cycles. However, when the partial charging process is carried out very frequently in succession, it has been shown that such incorrect calculations have a negative effect on the function and availability of the energy store.

It has been shown that a potential consequence of such erroneous calculations is that the accumulator is not fully charged during the set full charge. This leads to a reduction in the performance of the energy store and thus to a reduction in the range of the motor vehicle. Furthermore, if the state of charge is erroneously deemed to be above the actual level, the accumulator may come to a stop or be damaged due to an excessively high power output. An erroneous charging time may also be derived.

Disclosure of Invention

The invention is therefore based on the object of providing a charging device, a motor vehicle having such a charging device, and a method for charging, by means of which, on the one hand, the longest possible service life of an energy store is achieved and, on the other hand, the full functionality and usability of the energy store are ensured.

The above-mentioned object is achieved by the solution of the claims, in particular by a charging device according to claim 1, a motor vehicle according to claim 4 and a method according to claim 10. Further advantages and details of the invention are given by the dependent claims, the description and the drawings. The features and details disclosed here in relation to the charging device according to the invention are of course also applicable in relation to the motor vehicle according to the invention and the method according to the invention and vice versa, so that the inventive aspects can always be mutually cited in respect of the disclosure.

According to a first aspect, the invention solves the object by means of a charging device having a charger for charging an energy store of a motor vehicle, wherein the charging device has a control unit which is provided for specifying (Vorgeben) a charging process of the energy store to be carried out by the charger, in the form of a full charge process or a partial charge process, wherein the charger charges the energy store to a state of charge of 100% during the full charge process and the charger charges the energy store to a state of charge of a value below 100% during the partial charge process, wherein the charging device is further provided such that, after a specified number of successive partial charge processes, the control unit specifies at least one full charge process.

Accordingly, the state of charge is recalibrated by forcing a full charge process after the actual number of successive partial charge processes, i.e. the number specified (or preset) and implemented. A continuous partial charging process is understood to mean a partial charging process which is directly successive to one another, i.e. there is no full charging process between the partial charging processes. The specification of the controller (Vorgabe) is to be understood as a control command given by the controller to the charger. The controller provides the charger with the specification that a partial or full charging process is to be carried out during the next charging or charging process. The charger implements the specification accordingly. Depending on the actual number of successive partial charging processes, the operating capacity can thus be determined after the full charging process, which is still relatively accurate, and therefore the state of charge can also be determined relatively correctly, i.e. without major deviations. Thereby avoiding the problems of the prior art described in the background section of this patent application.

The specified number of successive partial charging processes can advantageously be selected such that, on the one hand, as few or as few problematic determination deviations as possible are caused, and, on the other hand, unnecessary full charging processes are not carried out, which shorten the service life of the energy store or impair the use of the motor vehicle. In any case, the prescribed number of times is at least two. The prescribed number of times may be, for example, at least five times or at least ten times or more. The predetermined number of times can be primarily a function of the technology and operating capacity of the energy store and can therefore be selected to be adapted to the technology and operating capacity of the energy store.

The energy accumulator may be a battery, in particular. The battery may be, for example, a lithium ion battery. The battery may be a traction battery of a motor vehicle. Accordingly, the motor Vehicle may be an Electric Vehicle, for example a fully Electric Vehicle (BEV) or a partially Electric Vehicle (PHEV) with a charger, but may also be a Fuel Cell Vehicle (FCV).

Since the state of charge is defined as the quotient of the remaining capacity and the operating capacity after the last full charge, a state of charge of 100% of course always relates to the operating capacity still available for the full charging process and not to the original operating capacity before or at the start of use of the energy storage.

It may be provided that the controller is arranged to count the actual number of consecutive partial charging sessions, to compare the actual number with a defined number of consecutive partial charging sessions, and to define a full charging session for the charger if the actual number of consecutive partial charging sessions equals the defined number of consecutive partial charging sessions.

The method can be carried out repeatedly, that is to say after a complete charging process, which is specified by the controller or by a user or driver of the motor vehicle. Thus, after each full charge process, the number of consecutive partial charge processes is set to zero and the count is restarted.

It may also be provided that the partial charging process is set up such that the charging device charges the energy store to a state of charge of 80% or less. Lower states of charge may, for example, include states of charge of 70%, 60%, or less. In these states of charge, the service life of most energy stores, in particular lithium-ion batteries, can be significantly increased.

According to a second aspect of the invention, the aforementioned object is achieved by a motor vehicle having an energy store and a charging device according to the first aspect of the invention connected to the energy store.

The motor vehicle may be, in particular, a fully electric motor vehicle (BEV), a partially electric motor vehicle (PHEV) having a charger, or a Fuel Cell Vehicle (FCV) having an electric motor. The motor vehicle may have a charging socket connected to the charger for connection to a charging station which supplies energy or current for charging the energy store. Alternatively, the charging socket may be omitted in the case of further charging techniques, for example inductive charging.

In addition to or instead of the integration of the controller in the motor vehicle, it is of course also possible for a charging station, which is in particular fixedly mounted, to comprise the controller. In the case of charging stations which are used only or predominantly by the user of the motor vehicle, the charging station comprising the control unit can still count the actual number of successive partial charging processes with sufficient reliability in order to specify a full charging process.

It may be provided that the motor vehicle has an interface connected to the controller, which interface is provided to enable a user to specify a full or partial charging process by means of the interface.

To this end, the interface may be connected to a controller. The user can thus control or influence the specification of the controller by means of the interface. The interface can be an operating unit of the motor vehicle and/or a wireless interface to an external device, such as a wirelessly connectable smartphone, tablet computer or computer and an application or program located thereon. The operating unit can be designed, for example, in the form of an operating surface, for example on a touch screen, or in the form of an operating unit with mechanical keys. By means of an operating unit or an application or program, the user can specify the charging process on his own accord, based on his own planned vehicle usage. In this way, he can always extend the service life of the energy storage device, provided that he does not require a state of charge of 100%, since he can foresee that his next trip or trips do not require the maximum driving range of the motor vehicle with the energy storage device fully charged until he can or wants to recharge the energy storage device.

In this case, it can be provided that the controller is configured to specify the full charge process after a specified number of consecutive partial charge processes has been carried out, even if the user selects a partial charge process by means of the interface.

Thus, by means of the interface, the full charging process is defined by the controller in preference to the user's specification. This may be necessary in order to ensure that the forced full charge process cannot be easily skipped.

Nevertheless, situations may arise in which a full charging process is not desired, since the user needs or wants to use the motor vehicle. In this connection, it can of course be provided that, despite the provision of a full charging process, the user of the motor vehicle can interrupt the charging process and use the motor vehicle.

It may also be provided that the user can reject the controller's specification of a full charge process. Accordingly, the controller can be set up to specify a full charge process (on the next charge) if a preceding full charge process, in particular specified by the controller, has been interrupted.

It may also be provided that the interface and the control are configured such that a user can specify a percentage value of the state of charge to which the energy store is charged during a part of the charging process.

This allows the user additional flexibility in specifying part of the charging process. It is possible here for the user to select the percentage values of the classification of the state of charge, for example 60%, 70%, 80% and 90%, or a rating to a percentage. A prompt, for example in the form of a color code or text, can be stored in relation to the percentage value, which prompt represents the influence on the service life of the energy store and/or the range of the selected option.

In this case, it can also be provided that the display device of the motor vehicle is configured to output a prompt when the controller specifies a full charging process after a defined number of partial charging processes.

The display device may in particular be an optical display device in the form of a screen, in particular a touch screen. Alternatively or additionally, the display device may also be an acoustic display device in the form of an alert tone or announcement. The display device and the interface, both designed as a touch screen, for example, can be designed as one device.

The display device can be used to display the specification of the full charge process to the user in order to obtain the full functionality of the energy store. It may be provided that the user can then confirm and/or reject the specification of a full charging process. This can be achieved by means of an interface. If the user does not confirm or reject the full charge process, the controller may be configured to re-specify the full charge process for the next charge process. This prevents, on the one hand, the motor vehicle from carrying out a full-charging process against the user's will, and, on the other hand, also prevents the user, for reasons of time or otherwise, from wanting to abort the full-charging process and therefore the next full-charging process is delayed and possibly the originally specified full-charging process is missed.

Finally, it is also possible that the controller is connected to a route planner of the motor vehicle or to a route planner outside the motor vehicle or can be connected thereto, wherein the controller is configured to prescribe a partial charging process if the energy store, which is charged only by a partial charging process, is also able to travel over the route of the route planner.

This makes it possible to carry out the partial charging process intelligently, without user intervention or specification. This reduces the burden on the user in the decision to prescribe the corresponding charging process, so that the comfort of using the motor vehicle as a whole is increased.

The route planner may be a navigation device, for example of a motor vehicle, in which the user enters his destination for the next trip or day and in which the route is calculated. Here, the route may be a continuous route having a plurality of destinations, and thus the route may include a plurality of trips. The route is accordingly understood to be the route to be traveled between two charging processes.

The route planner may also be an intelligent route planner, which may for example have access to or include a calendar and schedule of a user of the motor vehicle. The route planner may be, for example, a smartphone, tablet, or computer with a corresponding application or program. The user may set the functionality accordingly, for example by sharing a calendar of a smartphone, tablet or computer.

In this respect, the application or program may assume the function of route planning, i.e. calculating a route according to a schedule in a calendar and estimating whether a full charging process is required or a partial charging process is sufficient to drive through the route. Accordingly, the application can specify a partial charging process and assume the functionality already mentioned of manually specifying the type of charging process, i.e. a partial charging process or a full charging process. The application can also determine the necessary state of charge for the route and accordingly specify this state of charge for a partial charging process.

According to a third aspect of the invention, the object is achieved by a method for charging an energy store of a motor vehicle, having the following steps:

(a) continuously charging the energy accumulator during a partial charging process, in which the energy accumulator is charged to a state of charge of a value below 100%;

(b) counting the number of successive partial charging processes;

(c) comparing the number of consecutive partial charging processes with a specified number of consecutive partial charging processes; and

(d) if the number of successive partial charging processes is equal to the specified number of successive partial charging processes, the energy store is charged during a full charging process.

The method according to the third aspect of the invention thus has the same advantages as the charging device according to the first aspect of the invention and the motor vehicle according to the second aspect of the invention. The method may also provide additional steps relating to the charging device and the characteristics of the vehicle.

It can therefore be provided that the user specifies a full charging process or a partial charging process, in particular by means of an interface. Furthermore, provision may be made for the full charging process to be specified after a specified number of consecutive partial charging processes has been carried out, even if the user selects a partial charging process by means of the interface. Furthermore, provision may be made for the user to be able to specify the percentage of the state of charge to which the energy store is charged during part of the charging process. In particular, the display device may output a prompt if a full charge process is specified after a defined number of partial charge processes. A route planner may also be provided, which specifies a partial charging process if the route of the route planner can be completed with an energy storage charged only by this partial charging process.

Further measures which improve the invention result from the following description of different embodiments of the invention which are shown schematically in the drawing. All features and/or advantages which are derived from the claims, the description or the figures, including structural details, spatial arrangements, can be essential to the invention both per se and in various combinations.

Drawings

The invention is explained in more detail below with the aid of the figures. In the drawings:

FIG. 1 shows a schematic view of a motor vehicle according to an embodiment of the invention; and

fig. 2 shows a schematic illustration of a method for charging an energy store of the motor vehicle in fig. 1, according to an exemplary embodiment of the present invention.

In fig. 1 and 2, elements having the same function and mode of action are provided with the same reference numerals, respectively.

Detailed Description

Fig. 1 shows a schematic view of a motor vehicle 1 according to an embodiment of the invention. The motor vehicle 1 is designed here as an electric vehicle with an electric motor 12.

The electric motor 12 is provided for driving the motor vehicle 1 and is connected to the energy store 2. The accumulator 2 provides electrical energy to the electric motor 12. For charging the energy store 2, the motor vehicle 1 has a charging device 3 with a charger 5. The charger 5 is connected to a charging station 7 in the form of a charging post by means of a charging socket 6 of the motor vehicle 1 and a charging cable 8 connected thereto. This allows the energy accumulator 2 to be charged.

The controller 4 of the charging device 3 controls the charger 5 and the charging process for charging the energy accumulator 2. The controller 4 can specify a full charging process V or a partial charging process T (see fig. 2 and the explanations relating thereto below) for the charger 5. This will be performed by the charger 5 during the next charging process.

During the full charge process V, the energy store 2 is charged to a state of charge of 100%. During the partial charging process T, the energy store 2 is charged only to a state of charge of less than 100%, for example less than 80%. Thereby, the state of charge is maintained in a range below the full charge state of 100% in order to extend the service life of the accumulator 2.

The display device 9, the interface 10 and the route planner 11 are connected to the charging device 3. The display means 9 enable the display of the corresponding charging process. By means of the interface 10, one of two charging processes, namely a full charging process V or a partial charging process T, can be selected. The route planner 11 can implement: the controller 4 determines, by means of one of the routes determined by the route planner, whether a full charging process V is required to complete the route until the next charging process, or whether a partial charging process T is sufficient to complete the route, so that the energy storage 2 does not have to be fully charged and its service life does not decrease unnecessarily.

Fig. 2 shows a schematic illustration of a method for charging the energy store 2 of the motor vehicle 1 from fig. 1 according to an exemplary embodiment of the present invention.

The user or driver of the motor vehicle 1 selects the first charging process by means of the interface 10. In this example, the first charging process is a first partial charging process t.1. During the continuous charging process, the driver of the motor vehicle 1 selects the partial charging process T, i.e. the second partial charging process t.2, again.

For this purpose, the user does not need to actively select the partial charging process T each time, if at all, and does not need to be able to display a corresponding selection request on the display device 9 before the charging process or leaving the motor vehicle 1. This may be a permanently selected setting which is specified as long as a full charge process V is not selected or, for example, the percentage state of charge of the partial charge process T is changed by the user.

The same applies to the continuous third part charging process T.3 through the xth part charging process T.X. Thereby, the actual number X of consecutive partial charging processes T is specified and implemented by the charger 3. By means of the actual number X of successive partial charging processes T, the energy store 2 of the motor vehicle 1 is protected and its service life is extended in comparison with the alternatively possible full charging process V.

In parallel with the specification of the charging process by means of the interface 10, the controller 4 counts the actual number X of successive partial charging processes T. This count is represented by the mathematical sum sign in fig. 2, but is also equal to X in this description and can therefore be replaced by X. This counting is carried out for the purpose of checking P or comparison, which takes place simultaneously with the specified charging process by means of the interface 10.

In a first checking step p.1, which takes place in parallel with the defined partial charging process t.1, it is checked whether the defined number of times Z of the partial charging process T is equal to the actual number X of consecutive partial charging processes T, i.e. the sum of the partial charging processes which have been carried out in succession up to now. This query or check is represented as an equation in fig. 2. The predetermined number of times Z is stored in the controller 4 in advance. In this step p.1, the equation does not hold. In other words, the prescribed number of times Z is not equal to the actual number of times X.

Accordingly, the check proceeds to check step p.2. The check is repeated there, wherein a partial charging process t.2 is added. If Z is not equal to 2, the equation is not true in this case either and the check proceeds to check step P.3. Finally, the check step P.X is reached, the specified number of times Z now being equal to the actual number of times X.

For example, Z may be chosen to be 10, so this is the case in the tenth part of the charging process T that is continuous. It should be noted here that, in contrast, after one of the first ten successive partial charging processes T in this example, any full charging process V interrupts the counting and the counting of the controller 1 resumes in the partial charging process T following the full charging process V.

If the user now wants or intends to specify a further partial charging process T, this is prevented by the controller 4. This process is indicated in the figure by the dashed arrow. Instead, the control unit 4 specifies a full charge process V in order to recharge the energy store 2.

Subsequently, the counting and checking of the actual number X of successive partial charging processes T or the comparison of this actual number with the specified number Z is repeated again, as long as the user specifies such partial charging processes T.

List of reference numerals

1 Motor vehicle

2 energy accumulator

3 charging device

4 controller

5 charger

6 charging socket

7 charging station

8 charging cable

9 display device

10 interface

11 route planner

12 electric motor

T part charging process

V full charging process

P checking step

Claims

1. A charging device (3) having a charger (5) for charging an energy store (2) of a motor vehicle (1), wherein the charging device (3) has a control device (4) which is provided for specifying a charging process of the energy store (2) to be carried out by the charger (5) in the form of a full charging process (V) or a partial charging process (T), wherein the charger (5) charges the energy store (2) to a state of charge of 100% in the full charging process (V) and the charger (5) charges the energy store (2) to a state of charge of a value below 100% in the partial charging process (T),

it is characterized in that the preparation method is characterized in that,

in order to recalibrate the state of charge of the energy store (2), the charging device (3) is also designed in such a way that the control device (4) specifies at least one full charge process (V) after a specified number (Z) of consecutive partial charge processes (T).

2. A charging arrangement (3) as claimed in claim 1, characterized in that the controller (4) is arranged to count the actual number (X) of consecutive partial charging processes (T), to compare this actual number with the prescribed number (Z) of consecutive partial charging processes (T), and to prescribe a full charging process (V) to the charger (5) if the actual number (X) of consecutive partial charging processes (T) equals the prescribed number (Z) of consecutive partial charging processes (T).

3. A charging device (3) according to claim 1 or 2, characterized in that the partial charging process (T) is arranged such that the charging device (3) charges the energy accumulator (2) to a state of charge of 80% or less.

4. A motor vehicle (1) having an energy accumulator (2) and a charging device (3) according to one of the preceding claims, which is connected to the energy accumulator (2).

5. Motor vehicle (1) according to claim 4, characterized in that the motor vehicle (1) has an interface (10) connected to the controller (4), which interface is provided such that a user can specify a full charge process (V) or a partial charge process (T) by means of the interface (10).

6. Motor vehicle (1) according to claim 5, characterized in that the controller (4) is arranged to prescribe the full charging process (V) even if the user selects a partial charging process (T) by means of the interface (10) after a prescribed number (Z) of consecutive partial charging processes (T) has been carried out.

7. A motor vehicle (1) as claimed in claim 5 or 6, characterized in that the interface (10) and the controller (4) are arranged such that a user can specify the value of the state of charge percentage to which the energy accumulator (2) is charged during a part of the charging process (T).

8. A motor vehicle (1) as claimed in any one of claims 5 to 7, characterized in that the display device (9) of the motor vehicle (1) is arranged to output a prompt when the controller (4) specifies a full charging process (V) after a defined number of partial charging processes (T).

9. Motor vehicle (1) according to one of the claims 5 to 8, characterized in that the controller (4) is connected to a route planner (11) of the motor vehicle (1) or to a route planner (11) outside the motor vehicle or connectable, wherein the controller (4) is configured to prescribe a partial charging process (T) when the energy storage (2) charged only by the partial charging process (T) can also be used to drive through the route of the route planner (11).

10. A method for charging an energy accumulator (2) of a motor vehicle (1), wherein the method comprises the following steps:

(a) continuously charging the energy storage (2) during a partial charging process, in which the energy storage (2) is charged to a state of charge of a value below 100%;

(b) counting the actual number (X) of consecutive partial charging processes (T);

(c) comparing the actual number (X) of consecutive partial charging processes (T) with the specified number (Z) of consecutive partial charging processes (T); and

(d) the energy store (2) is charged in a full charge process (V) if the number (X) of successive partial charge processes (T) is equal to the specified number (Z) of successive partial charge processes (T).