Method for determining a setpoint value of a charging output for charging a battery of a vehicle by means of a charging device

Abstract

The invention relates to a method for determining a setpoint value of a charging output for charging a battery (32) of a vehicle (30) by means of a charging device (12), the charging device (12) being electrically connectable to a photovoltaic system (14) and to a consumer system (20), comprising the following steps: - reading in an item of output information, which represents a difference between actual values of an output provided by the photovoltaic system (14) and an output removed by the consumer system (20) and a charging output provided by the charging device (12) for the charging of the battery (32) of the vehicle (30), by means of a computing unit (28); and - determining the setpoint value of the charging output on the basis of the read-in output information by means of the computing unit (28), wherein the determined setpoint value of the charging output represents a surplus of the provided output, in order to charge the battery (32) of the vehicle (30) with the determined setpoint value of the charging output by means of the charging device (12), wherein, depending on the output information to be read in, in particular when it is not available, - an item of reference output information is read in by means of the computing unit (28) and - the setpoint value of the charging power is determined on the basis of the read-in reference output information.

Description

[0001] Description

[0002] title

[0003] Method for determining a target value of a charging power for charging a battery of a vehicle by means of a charging device

[0004] The invention relates to a method for determining a target value of a charging power for charging a battery of a vehicle by means of a charging device, a computing unit, a charging device and a system, as well as a corresponding computer program and a storage medium.

[0005] State of the art

[0006] In 2020, it was discovered that approximately 89 percent of house roofs in Germany are not yet equipped with their own photovoltaic system. To further exploit this potential for generating renewable energy, the legislature plans to make photovoltaic systems mandatory for both new buildings and renovations of existing buildings. In addition, in recent years, the legislature has paid several hundred million euros in subsidies to private households to enable the installation of appropriate charging facilities (so-called wall boxes) for battery-electric vehicles in private homes. Both measures help reduce dependence on fossil fuels.In this context, for the joint operation of photovoltaic systems, charging stations, and battery-electric vehicles, it is important to ensure that a high proportion of the available solar energy is actually used by the vehicle or other electrical devices in the household, and that unnecessary energy purchases from the power grid are avoided. If a so-called surplus of electrical power nevertheless arises, this power is fed back into the power grid and compensated for.

[0007] Excess charging considers the situation where a battery-electric vehicle is connected to the wallbox and does not necessarily need to be charged as quickly as possible. This could be because there is sufficient remaining capacity in the battery for upcoming short journeys, or because the next journey is not planned for a few days. Furthermore, the vehicle's battery should not be fully charged so that further excess solar energy can still be absorbed. Now, with excess charging, the question arises as to how exactly the surplus power can be used to charge the vehicle's battery. There are various strategies for this, which differ in their complexity, implementation effort, and ultimately also in the acquisition cost.

[0008] In the simplest case, this involves time-based control, where the charging device is switched on at a specific time and switched off again a few hours later. During this period, the vehicle's battery is charged with a constant electrical output. Of course, fluctuations in the solar power generated may not be taken into account, and additional electrical power may have to be purchased, for example, in the event of a drop in solar power due to cloud formation. Furthermore, with this simple strategy, any surplus solar energy cannot be fully absorbed by the vehicle's battery.

[0009] If you also have a measuring device available that can determine the solar energy generated and the energy fed into the power grid, you can easily adjust the charging power for your battery-electric vehicle, ensuring that your own consumption is optimized. However, the measuring device usually requires an additional cable connection between the charging device and the measuring device in the control cabinet, which, apart from electrical systems in new buildings, often entails considerable retrofitting costs.

[0010] DE 10 2022 203 741 A1 discloses a method for determining a target value of a charging power for charging a vehicle battery by means of a charging device. The charging device is electrically connectable to a photovoltaic system and a consumer system. Power information representing a difference between actual values ​​of a power provided by the photovoltaic system and a power consumed by the consumer system and a charging power provided by the charging device for charging the vehicle battery is read in. Furthermore, the target value of the charging power is determined based on the power information using a control algorithm, wherein the determined target value of the charging power represents a surplus of the power provided in order to charge the vehicle battery with the target value of the determined charging power by means of the charging device.

[0011] Disclosure of the invention

[0012] According to a first aspect, the subject of the present invention is a method for determining a target value of a charging power for charging a battery of a vehicle by means of a charging device and / or for charging a battery of a vehicle with a determined target value of a charging power by means of a charging device according to claim 1. In this case, the charging device is electrically connectable, in particular electrically connected, to a photovoltaic system and a consumer system.

[0013] The method comprises a step of reading in power information representing a difference between actual values ​​of the power provided by the photovoltaic system and the power consumed by the consumer system, and a charging power provided by the charging device for charging the vehicle's battery. In other words, the power information represents a difference between an actual value of the power provided by the photovoltaic system and an actual value of the power consumed by the consumer system, and an actual value of the charging power provided by the charging device for charging the vehicle's battery.

[0014] The method further comprises a step of determining the target value of the charging power based on the power information, in particular using a control algorithm, by means of a computing unit, wherein the determined target value of the charging power represents a surplus of the power provided in order to charge the battery of the vehicle with the determined target value of the charging power by means of the charging device.

[0015] In this case, depending on the power information to be read in (by means of the computing unit), in particular if it is not available, a reference power information is read in by means of the computing unit, and the target value of the charging power is determined, in particular if it is alternatively or furthermore based on the read in reference power information (by means of the computing unit). In other words, the target value of the charging power can be determined depending on the power information to be read in, either based on the power information and / or based on the reference power information. Preferably, if the power information to be read in is available, the target value of the charging power is determined based on the power information and independently of the reference power information.If the power information to be read in is not available, the target value of the charging power is preferably determined based on the reference power information and, in particular, independently of the difference between the actual values ​​represented by the power information.

[0016] Preferably, the steps of the method, in particular the steps of reading in the performance information and determining the target value, are carried out repeatedly, preferably cyclically, for example periodically.

[0017] According to a second aspect, the subject of the present invention is a computing unit for determining a charging power for charging a battery of a vehicle by means of a charging device according to claim 10.

[0018] According to a third aspect, the present invention relates to a charging device for charging a battery of a vehicle according to claim 11.

[0019] According to a fourth aspect, the present invention provides a system for charging a battery of a vehicle according to claim 12.

[0020] According to a further aspect, the present invention relates to a computer program and a machine-readable storage medium.

[0021] The vehicle comprises a battery configured to at least partially supply a drive unit, in particular an electric motor, of the vehicle with electrical energy. It is conceivable that the vehicle is a battery-electric vehicle or a hybrid vehicle. The vehicle can be a land vehicle, an aircraft, or a watercraft. For example, the vehicle is a car, a truck, an e-bike, an electrically powered helicopter, or an electrically powered boat.

[0022] The vehicle includes a charging interface which is electrically connectable to a charging interface of the charging device in order to charge or discharge the vehicle's battery.

[0023] The charging device comprises at least one additional charging interface for connecting the charging device directly or indirectly to the photovoltaic system and / or the consumer system. The charging device is preferably designed as a wallbox. It is conceivable that the charging device is arranged on an infrastructure element or a building.

[0024] The photovoltaic system comprises one or more photovoltaic modules and an inverter. The photovoltaic modules are arranged, for example, on the roof of a building. The photovoltaic system is designed to provide electrical power generated by the photovoltaic modules and converted into alternating current by the inverter. The photovoltaic system can also include one or more electrical storage units, e.g., battery storage units, which are designed, in particular, to receive or take up power provided by photovoltaic modules of the photovoltaic system and to temporarily store it. The storage unit of the photovoltaic system is designed to provide the stored electrical energy to the charging device.

[0025] The consumer system comprises one or more consumers different from the vehicle, which are preferably arranged on or in the building. The consumer system can also comprise one or more electrical storage units, e.g., battery storage units, which are designed, in particular, to receive or take away and store power provided by the photovoltaic system. The storage unit of the consumer system is designed to provide the stored electrical energy to the charging device.

[0026] Preferably, the charging device, the photovoltaic system and the consumer system are indirectly electrically connectable or connected to one another by means of a distribution unit, in particular arranged on or in the building.

[0027] A surplus of supplied power can be understood as a difference between the power supplied by the photovoltaic system or the solar power and the power consumed by the consumer system or the consumer power, whereby the difference is preferably positive.

[0028] In the context of this application, an actual power value can be understood as a current, instantaneous, or current power value. In the context of this application, a target power value can be understood as a determined power value into which the actual power value is to be or is being converted, particularly for the purposes of a control.

[0029] Reading the power information is preferably preceded by a sensor-based detection or measurement of the difference between the actual values ​​of the power provided by the photovoltaic system, the power consumed by the consumer system, and the charging power provided by the charging device for charging the vehicle's battery. It is conceivable that the difference is detected or measured, for example, at an interface to an electrical supply grid. For example, the difference can be detected as power delivered to the electrical supply grid or provided by the electrical supply grid.

[0030] Alternatively or additionally, in the sensory detection or measurement step, the actual value of the power provided by the photovoltaic system, the actual value of the power consumed by the consumer system, and the actual value of the charging power provided by the charging device for charging the vehicle's battery can be detected or measured in order to determine or calculate the difference based on the detected actual values. The detection or measurement of the power or the power difference can be carried out, for example, using one or more electrical power measuring units. The power information is, in particular, a digital or analog signal that represents the difference between the actual values ​​of the power provided by the photovoltaic system, the power consumed by the consumer system, and the charging power provided by the charging device for charging the vehicle's battery.

[0031] According to a preferred embodiment, the difference between the actual values ​​and / or the actual values ​​are transmitted to the computing unit via a wireless communication connection. Reading the performance information may include receiving the difference between the actual values ​​transmitted using the wireless communication connection and / or receiving the actual values ​​transmitted using the wireless communication connection. The wireless communication connection may, for example, comprise a cellular connection and / or a Wi-Fi connection.

[0032] When transmitting the difference between the actual values ​​and / or the actual values ​​using a wireless communication connection, the availability of the transmitted values ​​or data depends on a quality of service, e.g. represented by stability or reliability, a minimum bandwidth, etc. If a minimum bandwidth fails or is undershot, the performance information to be read in cannot be made available to the computing unit. According to the present approach, particularly if the performance information to be read in is not available, the reference performance information can be read in by the computing unit as a substitute for, instead of, or instead of the performance information. In other words, the reference performance information is preferentially read in precisely the case in which the performance information is not available to the computing unit.

[0033] The performance information is (not) available to the computing unit if it is (not) possible to read the performance information by the computing unit, in particular if the performance information is (not) readable, retrievable, or receivable by the computing unit. It is conceivable that an error in data transmission and / or data storage could also result in the unavailability of the performance information. Therefore, the reference performance information is preferably read in as a substitute in the event of unavailability, in particular in the event of a failure, of a wireless communication connection for transmitting the difference between the actual values ​​and / or the actual values ​​to the computing unit.

[0034] In this case, reading the service information can include checking the availability of the service information. In other words, the availability or unavailability of the service information can be checked or verified during the reading step. The reading step can therefore include determining the unavailability of the service information. In this sense, the read service information can represent information about the unavailability of the service information.

[0035] Alternatively or additionally, the reference power information can also be read in in addition to the power information in order to check the plausibility of the read-in power information using the reference power information. It is conceivable that the target value of the charging power is determined based on the power information if the power information deviates from the reference power information by less than a predetermined maximum value. It is also conceivable that the target value of the charging power is determined based on the reference power information if the power information deviates from the reference power information by at least the predetermined maximum value. This allows implausible differences from actual values ​​represented by the power information to be detected and disregarded when determining the target value.

[0036] Thus, reading in the reference performance information depending on the performance information to be read in can be understood as a dependency on the availability or presence of the performance information for the computing unit and / or a dependency on a value, in particular a plausibility of the value, the difference between the actual values ​​represented by the performance information and / or, in particular a plausibility of the actual values.

[0037] The reference performance information can be read from a storage unit assigned to the computing unit or a storage medium assigned to the computing unit. The storage unit is preferably connected to the computing unit via a wired communication connection.

[0038] The computing unit may have one or more hardware and / or software interfaces for reading in or receiving the power information and / or the reference power information. The computing unit may have one or more hardware and / or software modules for determining or calculating the target value of the charging power. The computing unit may have a hardware and / or software interface for outputting a signal containing information regarding the determined target value of the charging power.

[0039] The computing unit can be arranged on the charging device, in particular integrated into the charging device. The computing unit can also be arranged away from the charging device, for example, within a building or on or in the vehicle, or can be part of a cloud computing environment. The computing unit arranged away from the charging device can be connected to the charging device wirelessly or by wire, in particular connected to transmit an analog or digital signal containing information regarding the determined target value of the charging power to the charging device. Preferably, the computing unit can be communicatively connected, in particular connected, to the photovoltaic system and / or the consumer system directly or indirectly, for example via a server backend, by means of a wireless communication connection.

[0040] The method and devices according to the invention now make it possible to provide a charging strategy for charging a vehicle battery, according to which the actual excess power available for charging can be efficiently approximated even when actual values ​​for solar power, consumer power, and / or charging power are unavailable and / or implausible. This allows the power provided by a photovoltaic system to be optimally utilized and additional power consumption from a supply grid or additional feed-ins into the supply grid to be minimized.

[0041] Advantageously, the reference power information represents a reference difference between the power provided by the photovoltaic system and the power consumed by the consumer system, and the charging power provided by the charging device for charging the vehicle's battery. The reference difference is, in particular, a difference determined independently of the difference represented by the power information.

[0042] It is advantageous if the reference power information is based on a first reference value for the power provided by the photovoltaic system, a second reference value for the power consumed by the consumer system and the actual value of the charging power provided by the charging device for charging the vehicle's battery.

[0043] It is conceivable that the actual value of the power provided by the photovoltaic system and / or the actual value of the power consumed by the consumer system is or should be transmitted to the computing unit via a wireless communication connection, and the actual value of the charging power provided by the charging device for charging the vehicle's battery is transmitted to the computing unit via a wired communication connection. If the wireless communication connection is unavailable (and the wired communication connection is available), only the actual value of the charging power can be provided to the computing unit, but not the actual values ​​of the power provided by the photovoltaic system and the power consumed by the consumer system.

[0044] According to this embodiment, the reference power information can be determined as the difference between the first reference value for the power provided by the photovoltaic system and the second reference value for the power consumed by the consumer system, and the actual value of the charging power provided by the charging device for charging the vehicle's battery. By providing the first and second reference values, the target value of the charging power can be reliably determined even if the actual power values ​​are partially unavailable or implausible.

[0045] Alternatively, it is advantageous if the reference power information is based on a first reference value for the power provided by the photovoltaic system and a second reference value for a sum of the power consumed by the consumer system and the charging power provided by the charging device for charging the vehicle's battery.

[0046] It is conceivable that the actual value of the power provided by the photovoltaic system and / or the actual value of the power consumed by the consumer system and / or the actual value of the charging power provided by the charging device for charging the vehicle's battery is or should be transmitted to the computing unit by means of a wireless communication connection, e.g. if the computing unit is part of a cloud computing unit or a server backend. If the wireless communication connection is not available, the actual values ​​of the power cannot be provided to the computing unit.

[0047] According to this embodiment, the reference power information can be determined as the difference between the first reference value for the power provided by the photovoltaic system and the second reference value for the sum of the power consumed by the consumer system and the charging power provided by the charging device for charging the vehicle's battery. By providing the first and second reference values, the target value of the charging power can be reliably determined even if the actual power values ​​are unavailable or implausible.

[0048] It is also advantageous if the reference performance information depends on a time of day, in particular further on a day of the week and / or a month, and the reference performance information to be read in is selected taking into account a current time of day, in particular further on a current day of the week and / or a current month. It is conceivable that a reference difference and / or a first and a second reference value are provided to the computing unit for a plurality of predetermined times of day, in particular for a plurality of predetermined combinations of times of day and / or days of the week and / or months. In this case, reading in the reference performance information can comprise reading out the reference performance information from a memory unit assigned to the computing unit as a function of a current time of day, further as a function of a current day of the week and / or a current month.Preferably, the reference power information is read from the storage unit for which an assigned time and / or an assigned day of the week and / or an assigned month deviates minimally from the current time and / or the current day of the week and / or the current month. This configuration allows time-of-day, weekday, and / or month-dependent variations in the power provided by the photovoltaic system, the power consumed by the consumer system, and / or the charging power to be taken into account when determining the target value.

[0049] It is also advantageous if the read-in reference performance information is

[0050] Measured values ​​of the power provided by the photovoltaic system and / or the power consumed by the consumer system and / or the charging power provided by the charging device for charging the vehicle's battery and / or a model of the photovoltaic system and / or the consumer system and / or the charging device. The measured values ​​can, for example, be the actual values ​​of the solar power and / or the consumer power and / or the actual values ​​of the charging power available when the power information is available. The reference power information can be determined or calculated before and / or during the runtime of the method based on the measured values.

[0051] The model can be a statistical or data-based and / or physical and / or self-learning model. The model can comprise one or more submodels. According to one embodiment, a first submodel represents the solar power, and a second submodel represents the consumer power or the charging power, or the sum of the consumer and charging power. It is also conceivable for the model to represent the difference between the solar power and the sum of the consumer and charging power. The model preferably comprises reference power information dependent on the time of day, the day of the week, and / or the month. The model preferably comprises a look-up table that assigns a reference power value to discrete times or time ranges.

[0052] This design allows for the provision of sufficiently accurate reference performance information for most operating situations with manageable implementation effort.

[0053] It is furthermore advantageous if the reference power information stored in a memory unit assigned to the computing unit and / or the first and / or second reference value stored in a memory unit assigned to the computing unit is updated or adjusted based on the actual values ​​when the power information is available. In other words, the reference value(s) for the power provided by the photovoltaic system and / or the reference value(s) for the power consumed by the consumer system are adjusted using the actual values ​​of the power provided by the photovoltaic system or the actual values ​​of the power consumed by the consumer system. With this configuration, when the actual values ​​are available, they can be used to further improve the model, in particular to reduce any deviation between the model and the actual values.

[0054] It is advantageous if the target value of the charging power is determined using a control algorithm, in particular comprising a controller with an integral component. The control algorithm is configured to regulate the difference between the actual values ​​of the power provided by the photovoltaic system and the power drawn by the consumer system and the charging power provided by the charging device for charging the vehicle's battery to a predetermined target value, preferably zero, in order to minimize the import of power from a supply grid for charging the vehicle's battery. Determining the target value of the charging power based on the read-in power information using a control algorithm preferably involves calculating the charging power as a function of the difference between the actual values.Depending on the quality of the control algorithm, the determined charging power may deviate from the actual excess power. The control algorithm preferably includes a controller with an integral component. For example, the controller can be an integral controller, a proportional-integral controller, or a proportional-integral-derivative controller. This allows the control algorithm to control as precisely as possible to the specified setpoint.

[0055] It is advantageous if the control algorithm is configured to determine the target value of the charging power taking into account at least one charging property of the charging device, wherein the at least one charging property is selected from: maximum charging power of the charging device, predefined charging power levels of the charging device. When determining the charging power, both the maximum charging power of the charging device as a first charging property and predefined charging power levels of the charging device as a second charging property are preferably taken into account. Taking into account the maximum charging power of the charging device can include reducing the determined charging power to the maximum charging power if the determined charging power is greater than the maximum charging power.Taking into account the specified charging power levels of the charging device can include increasing or reducing the determined charging power to that of the specified charging power levels that deviates minimally, positively or negatively, from the determined charging power. This configuration allows typical non-linear characteristics of the charging device, such as, for example, the charging current, to be taken into account when determining the target charging power value.

[0056] Power limitations as well as quantization steps for voltage and charging current must be taken into account.

[0057] It is advantageous here if the control algorithm comprises a charging device model with an anti-wind-up feedback loop to take the at least one charging characteristic of the charging device into account when determining the target charging power value. The anti-wind-up feedback loop is preferably configured to subtract a difference between an input variable of a charging device model representing the at least one charging characteristic of the charging device and an output variable of the charging device model from an input variable of a controller of the control algorithm. This configuration can significantly improve the control quality and further reduce power imports / exports from the supply grid.It is further advantageous if the method comprises a step of charging the battery of the vehicle with the determined target value of the charging power by means of the charging device, wherein, in particular, additional power is provided to the charging device by means of a power supply unit only if the determined target value of the charging power is greater than a difference between the power provided by the photovoltaic system and the power consumed by means of the consumer system, or additional power is provided to a power consumption unit by means of the charging device if the determined target value of the charging power is smaller than the difference between the power provided by the photovoltaic system and the power consumed by means of the consumer system.

[0058] In other words, if the determined target value of the charging power, which represents a calculated available surplus of power provided by the photovoltaic system, deviates from the actually available surplus, or if there is no surplus at all, either additional power can be provided by the power supply unit to the charging device or power can be provided by the charging device to the power consumption unit. The power consumption unit and / or power consumption unit can be a local storage unit, e.g., an electrical storage device such as a battery. It is also conceivable for the power consumption unit and / or power consumption unit to be designed as an electrical supply network fed by one or more power plants.This design ensures that the vehicle is actually charged with the determined target value of the charging power, regardless of whether the actual surplus power corresponds to the determined surplus power.

[0059] Also advantageous is a computer program product or computer program with program code that can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and is used to carry out, implement and / or control the steps of the method according to one of the embodiments described above, in particular when the program product or program is executed on a computer or a computing unit.

[0060] In the following, the invention will be explained in more detail with reference to the drawings.

[0061] To show

[0062] Fig. 1 is a schematic diagram of an electrical network for photovoltaic surplus charging of a vehicle;

[0063] Fig. 2 is a block diagram of a controlled system according to a

[0064] embodiment;

[0065] Fig. 3 is a block diagram of a control circuit according to a

[0066] embodiment;

[0067] Fig. 4 is a block diagram of a further control circuit according to an embodiment;

[0068] Fig. 5 a schematic representation of models for the

[0069] Solar power and consumer power; and

[0070] Fig. 6 is a flowchart of a method for determining a

[0071] Charging power for charging a vehicle battery.

[0072] Fig. 1 shows a schematic representation of an electrical network which enables photovoltaic surplus charging of a battery-electric vehicle 30, for example at a residential building 10.

[0073] A charging device 12 configured as a wallbox 12, a photovoltaic system 14 with photovoltaic modules 16 and an inverter 18, and a consumer system 20 with one or more electrical consumers are arranged on the residential building 10. Furthermore, the residential building 10 includes an electrical distribution unit 22. The photovoltaic system 14 is configured to supply electrical power generated by the photovoltaic modules 16 and converted into alternating current by the inverter 18 to the consumer system 20, the charging device 12, and / or to a supply network 26 electrically connecting the residential building 10 to a power plant.For this purpose, the distribution unit 22 comprises a plurality of electrical interfaces designed to enable an electrical connection between the distribution unit 22 and the inverter 18, between the distribution unit 22 and the consumer system 20, between the distribution unit 22 and the charging device 12, and between the distribution unit 22 and the supply network 26. According to the present exemplary embodiment, the charging device 10 is electrically connected to the photovoltaic system 14 and the consumer system 20 indirectly via the distribution unit 22.

[0074] The charging device 12 is assigned a computing unit 28, which can be arranged on the charging device 12, in particular integrated into the charging device 12. According to the present embodiment, the computing unit 28 is connected to the inverter 18 of the photovoltaic system 14 or to an electrical current sensor arranged on the photovoltaic system 14 by means of a wireless communication connection, for example a mobile phone connection or a WiFi connection. Furthermore, the computing unit 28 is connected to an electrical current sensor (not shown) at a house connection point of the residential building 10 by means of another wireless communication connection, for example a mobile phone connection or a WiFi connection.By means of the wireless communication connections, the computing unit 28 can be provided with actual values ​​of a power provided by the photovoltaic system 14 as well as a difference between actual values ​​of a power consumed by the consumer system 20 and a charging power provided by the charging device 12 for charging the battery 32 of the vehicle 30.

[0075] The computing unit 28 is configured to determine a target value of a charging power for charging a battery 32 of the vehicle 30 using the charging device 12. For this purpose, the computing unit 28 comprises a processor, a storage medium with a computer program, and at least one communication interface. The computer program comprises instructions which, when executed by the processor, cause the target value of the charging power for charging the battery 32 of the vehicle 30 to be determined according to the method described below.

[0076] For this purpose, the computing unit 28 is configured to read in power information relating to a difference between an actual value of power provided by the photovoltaic system 14 and an actual value of power consumed by the consumer system 20 and an actual value of charging power provided by the charging device 12 for charging the battery 32 of the vehicle 30. Furthermore, the computing unit 28 is configured to determine the target value of the charging power based on the read-in power information. The determined target value of the charging power represents a surplus of the power provided in order to charge the battery 32 of the vehicle 30 with the determined target value of the charging power by means of the charging device 12.

[0077] In addition, the computing unit 28 is configured to read in reference power information depending on the power information to be read in, in particular if it is not available, and to determine the target value of the charging power based on the read-in reference power information.

[0078] Fig. 2 shows a block diagram of a control system 34 underlying the charging of the vehicle 30 with the determined charging power. The control system 34 is provided with the charging power P determined by the computing unit 28 as a control variable or control intervention. ba tt,ref and a ls controlled variable a power P provided to the supply network 26 or a power P taken from the supply network or exported to the supply network grid assigned.

[0079] Here, the power P grid, which is exported to the supply network 26 or imported from the supply network 26, simplified to a difference between a power P provided by the photovoltaic system 16 so iar and the charging power P batt , by means of which the battery 32 of the vehicle 30 is charged, as well as the power Pconsumer> consumed by the consumer system 20, which corresponds to the current consumption of all other electrical devices of the residential building 10:

[0080] Pgrid Psoiar Pbatt Pconsumer Furthermore, the control system 34 takes into account a first charging property 36 of the charging device 12 and a second charging property 38 of the charging device 12.

[0081] The first charging property 36 represents a maximum charging power of the charging device 12, which can be provided by the charging device 12 to charge the battery 32 of the vehicle 30, for example, 11 kW. The charging device 12 is configured to charge the battery 32 of the vehicle 30 with the maximum charging power when the determined charging power P ba tt,ref exceeds the maximum charging power.

[0082] It is also conceivable that the first charging characteristic 36 additionally represents a maximum negative charging power of the charging device 12, which can be maximally absorbed by the battery 32 of the vehicle 30 and made available to the consumer system 20 by means of the charging device 12. In this way, using the presented control algorithm, a power drawn by the consumer system 20 can also be covered by the battery 32 of the vehicle 30 alternatively or in addition to the photovoltaic system 14 if insufficient solar power is available.

[0083] The second charging characteristic 38 represents predetermined charging power levels of the charging device 12, according to which the charging power available for charging the battery 32 of the vehicle 30 is discretized, e.g., 1.4 kW, 3.7 kW, 7.4 kW, 11 kW. The charging device 12 is configured to charge the battery 32 of the vehicle 30 with a charging power that deviates minimally from the determined charging power in terms of magnitude, either positively or negatively.

[0084] In other words, the control system 34 takes into account typical non-linear features of the charging device 12, such as power limitations and quantization steps for voltage and charging current. The non-linear properties of the charging device 12 or wallbox 12 preferably include a quantization of the charging current or charging power and a lower limit at zero (i.e., no feedback from the vehicle 30 into the charging device 12 or into an electrical network of the residential building 10) as well as an upper limit determined by an electrical design of the charging device 12. Fig. 3 shows a block diagram of a control loop according to one embodiment. The control loop is designated in its entirety by the reference numeral 40 and comprises a control algorithm 42, which can be implemented, for example, as software, and the control system 34 according to Fig. 2.

[0085] According to this embodiment, the control algorithm 42 comprises an integral controller. It is also conceivable for the control algorithm 42 to comprise an alternative controller with an integral component, for example, a proportional-integral controller (PI controller) or a proportional-integral-derivative controller (PID controller).

[0086] The control algorithm 42 is set up, the controlled variable Pg rid to a given setpoint, in particular Pg rid = 0 in order to avoid having to purchase additional power from the supply network 26.

[0087] It is also conceivable that the controlled variable Pg rid by means of the control algorithm 42 to a specified setpoint Pg rid> 0. This allows the next higher power level of the charging device 12 to be selected, so that the solar power provided by the photovoltaic system 14 can be fully used to charge the battery 32 of the vehicle 30 by supplementing it with small amounts of power purchased from the supply grid 26.

[0088] The control algorithm 42 further includes a charging device model 44 with an anti-wind-up feedback. The charging device model 44 represents at least one charging characteristic of the charging device 12, preferably the first charging characteristic 36 and the second charging characteristic 38 according to Fig. 2.

[0089] The anti-wind-up feedback is configured to subtract a difference between an input of the charger model 44 and an output of the charger model 44 from an input of the integral controller. In other words, an output of the charger model 44 is subtracted from an input of the charger model 44 and then applied negatively to an input of the integrator.

[0090] Thus, typical, particularly non-linear, properties or characteristics of the charging device 12 can be explicitly taken into account in the control algorithm 42 using the charging device model 44 and the anti-wind-up feedback. This prevents the integral component in the controller from stopping when the charging device 12 is, for example, at its power limit. Likewise, it makes it possible to prevent a switching process from a first to a second power level of the charging device 12 from occurring if a value of the manipulated variable lies between two power levels.

[0091] Fig. 4 shows a block diagram of another control loop according to an embodiment. The control loop is designated in its entirety by reference numeral 40'.

[0092] In addition to the charging device 12 or wallbox 12, the inverter 18 and the battery 32, the control circuit 40' comprises a software module 46 and a model 48 of the photovoltaic system 14 assigned to the software module 46.

[0093] The software module 46 comprises a programming interface for the inverter 18. Furthermore, the software module 46 can comprise control software for the charging device 12. Preferably, the software module 46 is stored on a computing unit associated with the charging device 12, for example, the computing unit 28 according to Fig. 1.

[0094] The model 48 assigned to the software module 46 can also be stored on the computing unit assigned to the charging device 12. The model 48 represents the expected power provided by the photovoltaic system 14, for example, depending on the time of day, season, etc.

[0095] The actual value of the power provided by the photovoltaic system 14, detected by the inverter 18, is transmitted to the software module 46 of the charging device 12 via a wireless communication connection, e.g., a Wi-Fi connection. In addition, this transmitted actual value of the solar power is used to improve the model of the photovoltaic system 14 or the power provided by the photovoltaic system 14 during runtime.

[0096] In other words, in the radio communication-based solution according to this embodiment, it is assumed that by means of one or more measuring devices the power P currently generated by the photovoltaic system 14 or the solar installation 14 soiar and the sum of the two benefits from P batt and P COnsumer can be measured and are available in the inverter 18 or an internet portal assigned to the inverter 18. Consequently, a query can be started on the charging device 12 side in the radio network using a programming interface, with which the above-mentioned measured values ​​are repeatedly read from the internet, for example, at specific times. Since the controller is intended to keep the power balance steady at a specified setpoint (e.g., close to zero), a controller with an integral component (e.g., I controller, PI controller, PID controller, etc.) is recommended for determining the setpoint P ba tt,ref for the charging device 12. If the radio network operates reliably and regular query of the measured values ​​is possible, the control system should operate properly and ensure that the surplus solar energy can be stored in the battery 32 of the electric vehicle 30.

[0097] In the event that the measured values ​​cannot be retrieved, appropriate substitute values ​​or reference values, particularly from a model, are used. In one possible embodiment, this model contains, for example, two submodels. The first submodel uses a lookup table to describe the course of P. soiar over the time of day. A second submodel uses another lookup table to describe the course of the sum of P batt and P CO nsumer also over the time of day. The submodels are determined using a machine learning algorithm and preferably continuously adjusted.

[0098] Fig. 5 shows a schematic representation of models for solar power (Fig. 5A) and consumer power (Fig. 5B), in particular for providing a look-up table which assigns a power value Psoiar or P to discrete prime times. consumer assigns.

[0099] For this purpose, the current day is divided into n time intervals. Depending on the number n of time intervals, the error between the actual power curve (solid line) over time and the approximated curve (dotted line) can be significantly reduced. However, this also requires more memory to implement the method in a processing unit.

[0100] For each time interval, the mean value of the measured solar power P soiar or the consumer power P CO The approximate function of these two quantities over time is ultimately determined by, for example, linear interpolation between the stored mean values. To account for changes in these two patterns over the seasons and, at the same time, strong fluctuations (e.g., due to weather influences or other special events with high energy consumption), various options are known to the expert.

[0101] According to one embodiment, the model is updated at runtime. For this purpose, an appropriate weighting of existing performance values ​​and the performance values ​​obtained at runtime can be performed.

[0102] If such a curve with power values ​​P 1>oid , P2,oid , P^.oid etc. for the solar power and / or the consumer power from the past and additionally a new current mean value P k m pn “ for a specific time interval k, the mean value can be adjusted using the following relationship:

[0103] The parameter represents a tuning factor. Depending on the setting of the parameter X, the weighting can be shifted either to the old values ​​or to the new current power value. Alternatively, the solar power and consumer power curves can be saved for each individual day, and, for example, average curves can be saved for each week for subsequent years. Other averaging options are conceivable.

[0104] In addition to the approach using the characteristic curve or another similarly structured data-based model that can be adjusted in real time, an alternative embodiment could also use a physical model to describe solar performance over time. In this case, selected physical parameters can be adjusted in real time.

[0105] Fig. 6 shows a flowchart of method 100 for determining a target value of a charging power for charging a vehicle battery using a charging device. The charging device is electrically connectable, in particular connected, to a photovoltaic system and a consumer system. In step 110, power information is read in, representing a difference between actual values ​​of a power provided by the photovoltaic system and a power consumed by the consumer system, and a charging power provided by the charging device for charging the vehicle battery.

[0106] Depending on the performance information to be read in, particularly if it is not available, reference performance information is read in alternatively or additionally in step 120.

[0107] In step 130, the target value of the charging power is determined by a computing unit, preferably using a control algorithm, wherein the determined target value of the charging power represents an excess of the provided power. The target value of the charging power is determined based on the input power information and / or based on the input reference power information.

[0108] In step 140, the vehicle's battery is charged using the charging device with the determined target value of the charging power. In particular, additional power is provided to the charging device by means of a power supply unit if the target value of the determined charging power is greater than a power difference between the power provided by the photovoltaic system and the power consumed by the consumer system. Alternatively, additional power is provided to a power consumption unit by means of the charging device if the determined target value of the charging power is smaller than the power difference between the power provided by the photovoltaic system and the power consumed by the consumer system.

Claims

Claims 1 . Method (100) for determining a target value of a charging power for charging a battery (32) of a vehicle (30) by means of a charging device (12), wherein the charging device (12) is electrically connectable, in particular connected, to a photovoltaic system (14) and a consumer system (20), comprising the following steps: Reading (110) power information, which represents a difference between actual values ​​of a power provided by the photovoltaic system (14) and a power consumed by the consumer system (20) and a charging power provided by the charging device (12) for charging the battery (32) of the vehicle (30), by means of a computing unit (28);and determining (130) the target value of the charging power based on the read-in power information by means of the computing unit (28), wherein the determined target value of the charging power represents an excess of the power provided in order to charge the battery (32) of the vehicle (30) with the determined target value of the charging power by means of the charging device (12), characterized in that depending on, in particular if the power information to be read in is not available, a reference power information is read in by means of the computing unit (28) and the target value of the charging power is determined based on the read-in reference power information.; 2. Method (100) according to claim 1, characterized in that the reference power information represents a reference difference between a power provided by the photovoltaic system (14) and a power taken off by means of the consumer system (20) and a charging power provided by means of the charging device (12) for charging the battery (32) of the vehicle (30).

3. Method (100) according to claim 1 or 2, characterized in that the reference power information is a first reference value for the power provided by the photovoltaic system (14), a second reference value for the power consumed by the consumer system (20) and the actual value of the charging power provided by the charging device (12) for charging the battery (32) of the vehicle (30).

4. The method (100) according to claim 1 or 2, characterized in that the reference power information is based on a first reference value for the power provided by the photovoltaic system (14) and a second reference value for a sum of the power consumed by the consumer system (20) and the charging power provided by the charging device (12) for charging the battery (32) of the vehicle (30).

5. Method (100) according to one of the preceding claims, characterized in that the reference performance information depends on a time of day, in particular further on a day of the week and / or a month, and the reference performance information to be read in is selected taking into account a current time of day, in particular further on a current day of the week and / or a current month.

6. Method (100) according to one of the preceding claims, characterized in that the read-in reference performance information on Measured values ​​of the power provided by the photovoltaic system (14) and / or the power consumed by means of the consumer system (20) and / or the charging power provided by means of the charging device (12) for charging the battery (32) of the vehicle (30) and / or a model of the photovoltaic system (14) and / or the consumer system (20) and / or the charging device (12).

7. Method (100) according to one of the preceding claims, characterized in that the data assigned to the computing unit (28) The reference performance information stored in the storage unit and / or the first and / or second reference value stored in a storage unit associated with the computing unit (28) is updated based on the actual values ​​when the performance information is available.

8. Method (100) according to one of the preceding claims, characterized in that the target value of the charging power is determined using a control algorithm, in particular comprising a controller with an integral component.

9. The method (100) according to any one of the preceding claims, characterized by a step of charging (140) the battery (32) of the vehicle (30) with the determined target value of the charging power by means of the charging device (12), wherein additional power is provided to the charging device (12) by means of a power supply unit if the determined target value of the charging power is greater than a difference between the actual values ​​of the power provided by the photovoltaic system (14) and the power drawn by means of the consumer system (20), or additional power is provided to a power consumption unit by means of the charging device (12) if the determined target value of the charging power is smaller than the difference between the actual values ​​of the power provided by the photovoltaic system (14) and the power drawn by means of the consumer system (20).

10. A computing unit (28) for determining a target value of a charging power for charging a battery (32) of a vehicle (30) by means of a charging device (12), wherein the charging device (12) is electrically connectable to a photovoltaic system (14) and a consumer system (20), and the computing unit (28) is configured to read in power information representing a difference between actual values ​​of a power provided by the photovoltaic system (14) and a power consumed by the consumer system (20) and a charging power provided by the charging device (12) for charging the battery (32) of the vehicle (30), and to determine the target value of the charging power based on the power information, wherein the determined target value of the charging power represents an excess of the power provided in order to charge the battery (32) of the vehicle (30) with the determined target value of the charging power by means of the charging device (12). characterized in that the computing unit (28) is configured to read in reference power information as a function of the power information to be read in, in particular if it is not available, and to determine the target value of the charging power based on the read-in reference power information.

11. Charging device (12) for charging a battery (32) of a vehicle, wherein the charging device (12) is electrically connectable, in particular connected, to a photovoltaic system (14) and a consumer system (20), comprises a computing unit (28) according to claim 10, and is designed to charge the battery (32) of the vehicle (30) with the target value of the charging power determined by means of the computing unit (28).

12. System for charging a battery (32) of a vehicle, wherein the system comprises a charging device (12) which is electrically connectable, in particular connected, to a photovoltaic system (14) and a consumer system (20) and a computing unit (28) according to claim 10, wherein the computing unit (28) is arranged away from the charging device (12) and the charging device (12) is designed to charge the battery (32) of the vehicle (30) with the charging power determined by means of the computing unit (28).

13. Computer program comprising instructions which, when executed on a computing unit, in particular according to claim 10, cause the computing unit to carry out the method (100) according to one of claims 1 to 9, and / or which cause the charging device (12) according to claim 11 and / or the system according to claim 12 to carry out the method (100) according to one of claims 1 to 9.

14. A machine-readable storage medium having stored thereon a computer program according to claim 13.

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