CN113682197B - Charging device, motor vehicle and method for charging an energy store of a motor vehicle - Google Patents

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 controller (4) which is provided for defining a charging process of the energy store (2) to be carried out by the charger (5), which charging process is 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% during the full charging process (V) and the charger (5) charges the energy store (2) to a state of charge of less than 100% during the partial charging process (T), wherein, for recalibration of the state of charge of the energy store (2), the charging device (3) is further configured such that, after a specified number of consecutive partial charging processes (T) of times (Z) are carried out, the controller (4) defines at least one full charging process (V). The invention also 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, a motor vehicle having such a charging device, and a method for charging an energy store of a motor vehicle.

Background

It is known from DE 10 2009 036 943 A1 to charge an energy store of a motor vehicle in a full charge mode or in a parking charge 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 service life of the accumulator.

The inventors have realized that in case a plurality of consecutive charging processes of the state of charge of the accumulator to a value below 100% takes place, erroneous determination of the operating capacity and thus 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 a result of the use of the accumulator, the accumulator ages and the operating capacity decreases. But 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. For a single partial charge, this calculation can still provide a good approximation, since the operating capacity of the accumulator generally drops significantly after a large number of charging cycles. However, when the partial charging process is carried out very frequently continuously, it has proven that such erroneous calculations have a negative effect on the function and the usability of the energy store.

It has been shown that a potential consequence of this miscalculation is that the accumulator is not fully charged during the set full charge. This results in a reduced performance of the accumulator and thus in a reduced range of the motor vehicle. Furthermore, if the state of charge is erroneously considered to be higher than the actual level, the accumulator may be stopped or damaged due to an excessively high power output. An erroneous charging time may also be derived.

Disclosure of Invention

The object of the present invention is therefore to provide 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 greatest possible service life of an energy store is achieved and, on the other hand, the complete function and availability of the energy store are ensured.

The above-mentioned object is achieved by the technical 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 accompanying drawings. The features and details disclosed here in relation to the charging device according to the invention are of course also applicable to the motor vehicle according to the invention and to the method according to the invention and vice versa, so that the inventive aspects can always be cited in relation to one another in the light of the disclosure.

According to a first aspect, the invention solves the stated object by a charging device having a charger for charging an energy store of a motor vehicle, wherein the charging device has a controller 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 charging process or a partial charging process, wherein the charger charges the energy store to a state of charge of 100% during the full charging process and the charger charges the energy store to a state of charge of a value below 100% during the partial charging process, wherein the charging device is further configured in such a way that, for recalibration of the state of charge of the energy store, the controller specifies at least one full charging process after a specified number of consecutive partial charging processes have been carried out.

Hereby, the state of charge is recalibrated in that the full charge process is forced after the actual number of consecutive partial charge processes, i.e. the prescribed (or preset) and implemented number of times. A continuous partial charging process is understood to mean a partial charging process directly following one another, i.e. no full charging process is present between the partial charging processes. The controller specification (Vorgabe) is understood to be the control commands that the controller gives to the charger. The controller specifies to the charger that a partial charging process or a full charging process is to be performed in the next charging or charging process. The charger implements the specification accordingly. As a result, depending on the actual number of successive partial charging processes, a still relatively accurate operating capacity can be determined after the complete charging process, and thus the state of charge can also be determined relatively accurately, i.e. without large deviations. Thereby avoiding the problems of the prior art described in the background section of this patent application.

The predetermined number of consecutive partial charging processes can advantageously be selected such that, on the one hand, no defined deviations or only defined deviations with little problems are caused as far as possible, 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 prescribed number of times may be primarily related to and may thus be selected to be compatible with the technology and operating capacity of the accumulator.

The energy store may in particular be a battery. 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 motor vehicle (BEV for short, english: battery ELECTRIC VEHICLE) or a partially electric motor vehicle (PHEV for short, english: plug-in Hybrid ELECTRIC VEHICLE) having a charger, but may also be a Fuel cell vehicle (FCV for short, english: fuel CELL VEHICLE).

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

It may be provided that the controller is arranged to count an actual number of consecutive partial charging processes, compare the actual number with a prescribed number of consecutive partial charging processes, and prescribe a full charging process for the charger if the actual number of consecutive partial charging processes is equal to the prescribed number of consecutive partial charging processes.

The method can be carried out repeatedly, that is to say after a complete charging process defined by the control unit or by the 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.

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

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

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

In addition to or instead of integrating the control unit in the motor vehicle, it is of course also possible for the charging station, in particular fixedly mounted, to comprise the control unit. In the case of charging stations which are used only or mainly by the user of the motor vehicle, the charging station comprising the controller can also still count the actual number of consecutive partial charging processes reliably enough to prescribe a full charging process.

It can be provided that the motor vehicle has an interface connected to the control unit, which interface is provided such that a user can define a full charge process or a partial charge process by means of the interface.

To this end, the interface may be connected to a controller. Thus, the user can control or influence the regulation 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 wireless-connectable smart phone, tablet or computer, and applications or programs located thereon. The operating unit may 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 the operating unit or the application or program, the user can specify the charging process himself on the basis of his intended vehicle use. In this way, he can always extend the service life of the accumulator, provided he does not need a state of charge of 100%, since he can foresee that his subsequent journey or journeys do not need the maximum range of the motor vehicle with the accumulator fully charged, until he can or wants to recharge the accumulator.

In this case, the controller may be configured to set the full charge process after a predetermined number of consecutive partial charge processes have been performed, even if the user selects a partial charge process by means of the interface.

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

Nevertheless, situations may arise in which a full charge process is not desirable, as the user needs or wants to use the vehicle. In this respect, it is of course possible to provide that the user of the motor vehicle can interrupt the charging process and use the motor vehicle, despite the fact that a full charging process is specified.

It may also be provided that the user can reject the control of the full charge process. Accordingly, the controller may be configured to prescribe a full charge process (at the next charge) if a previous full charge process, in particular prescribed by the controller, has been interrupted.

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

This allows the user additional flexibility in defining the partial charging process. It is possible here for the user to select the percentage values of the charge state classification, for example 60%, 70%, 80% and 90% or precisely to the percentage level. A prompt, for example in the form of a color code or text, may be stored with respect to the percentage value, which prompt indicates the effect 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 charge process after a defined number of partial charge 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 a prompt tone or announcement. For example, the display device and the interface, both of which are designed as touch screens, may be designed as one device.

The display device can be used to display the regulation of the full charge process to the user in order to obtain the full function of the energy store. It may be provided that the user can then confirm and/or reject the provision of the full charge 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-prescribe the full charge process for the next charge process. This prevents, on the one hand, the motor vehicle from carrying out the full charge process against the user's wish, and, on the other hand, the user also from wanting to discard the full charge process for time reasons or other reasons, and thus the next full charge process is delayed and the originally prescribed full charge process may be missed.

Finally, it can also be provided that the controller is connected or connectable to a route planner of the motor vehicle or to a route planner outside the motor vehicle, wherein the controller is configured to prescribe a partial charging process when an accumulator charged by only the partial charging process can also be used to drive the route of the route planner.

This allows a part of the charging process to be carried out intelligently without user intervention or provision. In this way, the user's effort can be reduced in the decision about specifying a corresponding charging process, so that the comfort of using the motor vehicle as a whole is increased.

The route planner may be, for example, a navigation device of the motor vehicle, into which the user enters his next journey or destination the next 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 travelled 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 a schedule of a user of the motor vehicle. The route planner may be, for example, a smart phone, tablet or computer with a corresponding application or program. The user may set the functions accordingly, for example by sharing a calendar of a smart phone, tablet or computer.

In this regard, an application or program may assume the function of route planning, i.e., calculating a route from a schedule in a calendar, and estimating whether a full charge process or a partial charge process is required to drive through the route. Accordingly, the application may define a partial charging process and assume the already mentioned functions of manually defining the type of charging process, i.e. a partial charging process or a full charging process. The application may also determine the necessary state of charge for the route and prescribe the state of charge accordingly for the 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, comprising the following steps:

(a) Continuously charging the accumulator during a part of the charging process, during which the accumulator is charged to a state of charge of a value below 100%;

(b) Counting the number of consecutive partial charging processes;

(c) Comparing the number of consecutive partial charging processes with a prescribed number of consecutive partial charging processes; and

(D) If the number of consecutive partial charging processes is equal to the prescribed number of consecutive partial charging processes, the accumulator is charged during the full charging process.

The method according to the third aspect of the invention therefore 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 further steps relating to the characteristics of the charging device and the motor vehicle.

It can therefore be provided that the user specifies a full charge process or a partial charge process, in particular by means of the interface. Furthermore, it may be provided that after a predetermined number of consecutive partial charging processes have been carried out, the full charging process is specified even if the user selects a partial charging process by means of the interface. It may furthermore be provided that the user is able to specify the percentage of state of charge to which the accumulator is charged during part of the charging process. It is also possible to provide that, if a complete charging process is specified after a defined number of partial charging processes, a display device outputs a prompt, in particular. A route planner may also be provided which prescribes part of the charging process if the route of the route planner can be completed with an accumulator which is charged only by this part of the charging process.

Further measures for improving the invention emerge from the following description of different embodiments of the invention which are schematically shown in the figures. All features and/or advantages deriving from the claims, the description or the drawings, including structural details, spatial arrangements, can be important to the invention not only per se but also 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 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 illustration of a motor vehicle 1 according to an embodiment of the invention. The motor vehicle 1 is here designed 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 supplies electric 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 peg by means of a charging socket 6 of the motor vehicle 1 and a charging cable 8 connected to the charging socket. Thereby charging the accumulator 2.

The controller 4 of the charging device 3 controls the charger 5 and the charging process for charging the energy store 2. The controller 4 may prescribe a full charge process V or a partial charge process T to the charger 5 (see fig. 2 and the description relating thereto below). This will be implemented by the charger 5 in the next charging process.

During the full charge process V, the accumulator 2 is charged to 100% state of charge. Whereas during part of the charging process T the accumulator 2 is charged only to a state of charge of a value below 100%, for example below 80%. Thereby, the state of charge is kept within a range of less than 100% full state of charge 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 corresponding charging process to be displayed. By means of the interface 10, one of two charging processes, namely the full charging process V or the 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 charge process V is required to complete the route until the next charge process, or whether a partial charge process T is sufficient to complete the route, so that the energy store 2 does not have to be fully charged and its service life does not unnecessarily decrease.

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

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

For this reason, 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 exiting the motor vehicle 1. This may be a permanently selected setting, which is specified as long as the full charge process V is not selected or the percentage of state of charge of the partial charge process T is changed by the user, for example.

The same applies to the continuous third partial charging process T.3 through the X-th partial charging process T.X. Thereby, the actual number X of consecutive partial charging processes T is specified and implemented by the charger 3. The accumulator 2 of the motor vehicle 1 is protected and its service life is extended by the actual number X of consecutive partial charging processes T compared to the alternative possible full charging processes V.

In parallel with the provision of the charging process by means of the interface 10, the controller 4 counts the actual number X of consecutive partial charging processes T. This count is represented in fig. 2 by a mathematical summation symbol, 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 is carried out simultaneously with the prescribed charging process by means of the interface 10.

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

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

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

If the user at this time wants or intends to prescribe a further partial charging process T, this is prevented by the controller 4. This process is indicated in the figure by the drawn arrow. Instead, the controller 4 defines a full charge process V in order to recharge the accumulator 2 fully.

Subsequently, the counting and checking of the actual number X of consecutive partial charging processes T or the comparison of the actual number with the prescribed number Z is repeated again, as long as the user prescribed such a partial charging process T.

List of reference numerals

1. Motor vehicle

2. Energy accumulator

3. Charging device

4. Controller for controlling a power supply

5. Charger (charger)

6. Charging socket

7. Charging station

8. Charging cable

9. Display device

10. Interface

11. Route planner

12. Motor with a motor housing having a motor housing with a motor housing

T part charging process

V full charging process

P checking step

Claims (10)

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 controller (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% during the full charging process (V) and the charger (5) charges the energy store (2) to a state of charge of a value of less than 100% during the partial charging process (T),

It is characterized in that the method comprises the steps of,

In order to recalibrate the state of charge of the energy store (2), the charging device (3) is further configured such that after a predetermined number (Z) of consecutive partial charging processes (T) the controller (4) prescribes at least one full charging process (V).

2. Charging device (3) according to claim 1, characterized in that the controller (4) is arranged to count the actual number (X) of consecutive partial charging processes (T), compare this actual number with a prescribed number (Z) of consecutive partial charging processes (T), and 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. 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 storage (2) to a state of charge of 80% or less.

4. Motor vehicle (1) having an energy store (2) and a charging device (3) according to any of the preceding claims, which is connected to the energy store (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 in such a way that a user can define 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 charge process (V) after a prescribed number (Z) of consecutive partial charge processes (T) have been carried out, even if the user selects a partial charge process (T) by means of the interface (10).

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

8. Motor vehicle (1) according to any 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) prescribes a full charge process (V) after a defined number of partial charge processes (T).

9. Motor vehicle (1) according to any of 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, wherein the controller (4) is arranged to prescribe a partial charging process (T) when a route is also possible through the route planner (11) using an energy store (2) which is charged only by the partial charging process (T).

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

(a) Continuously charging the accumulator (2) during a partial charging process, during which the accumulator (2) is charged to a state of charge of a value lower than 100%;

(b) Counting the actual number (X) of successive partial charging processes (T);

(c) Comparing the actual number (X) of consecutive partial charging processes (T) with a prescribed number (Z) of consecutive partial charging processes (T); and

(D) If the number (X) of consecutive partial charging processes (T) is equal to the prescribed number (Z) of consecutive partial charging processes (T), the energy store (2) is charged in a full charging process (V).