DE102022119768A1 - Optimized charging management for an electric vehicle - Google Patents

Abstract

A method for charging an electric vehicle (2) and an associated charging control (6) of the electric vehicle (2) are specified. According to the method, a default value (V) for the charging current strength or charging power of a charging current (IL) obtained from the electric vehicle (2) is specified by the charging controller (6) in a time-varying manner.

Description

The invention relates to a method for charging an electric vehicle (E-vehicle for short) and to a charging control of the E-vehicle set up to carry out the method.

E-vehicles usually obtain the charging current required to charge their battery directly from a local power distribution (in particular by connecting the e-vehicle to a household socket or power socket) or from a charging station, which is either directly or indirectly connected to a public power distribution via a local power distribution The power grid can be connected to provide charging current for the electric vehicle. In the latter case, the charging station enables the charging process (i.e. the output of the electrical charging current) through communication with a charging controller of the electric vehicle and thereby specifies a (vehicle-internal) default value for the current strength or power of the charging current. This default value defines the maximum current strength or power of the charging current that the electric vehicle can access. Within the framework of this default value, the charging control of the electric vehicle then controls the charging current actually drawn during the charging process. With DC chargers, the vehicle is responsible for controlling the charging current within the permitted current levels. This defines the charging current that the DC charger should provide.

Here and below, “local power distribution” refers to the electrical installation that is separated from the public power grid by a network connection point, e.g. of a house (domestic power installation) or commercial business. The local electricity distribution therefore includes those electrical lines and consumers as well as any storage and/or power generation units that are located on this side of the network connection point from the perspective of the connected electric vehicle and therefore do not belong to the public electricity network.

When the electric vehicle is directly connected to the local power distribution, the charging process is regularly started immediately. Conventional charging stations also usually enable the charging process as soon as the electric vehicle to be charged is connected to the charging station. The default value of the charging current or power can often be set at the charging station or in the electric vehicle or using an app that works on the charging station or the electric vehicle. In these cases, the electric vehicle is charged depending on a specified maximum current or power.

Particularly in the case of electric vehicles that are charged from the domestic electricity installation of a private house equipped with a photovoltaic system (PV system), there is a strong need for the charging current for the electric vehicle to come as much as possible from - not for The electricity required for the house can be obtained from the surplus power of the PV system. The proportion of the solar power generated by the PV system used for personal use (i.e. domestic electricity needs and charging the electric vehicle) should be increased and the solar power should be fed back into the public power supply network (also “supply network” or “grid” for short) as far as possible be avoided. Furthermore, supply of charging current from the network should be avoided or at least largely reduced.

In order to achieve this goal, solar power-optimized charging stations are already being used today. Such charging stations either have a digital input to query performance data from the PV system via a communication device and then regulate the charging power or are digitally regulated by an intermediary energy control. This energy control usually accesses data from the PV inverter or a smart meter (i.e. an electricity meter set up to send the collected measurement data). The smart meter usually has to be installed in addition to existing meters in the sub-distribution of the house and then sends the charging station a signal that controls the charging power. The communication between the PV inverter or the smart meter on the one hand and the charging station on the other hand takes place either wired, e.g. via an RS485 bus, or wirelessly via radio, e.g. via WLAN. Sometimes the charging station and the PV inverter or smart meter are integrated into a smart home installation.

Charging stations that are sold in combination with one or more current sensors are also known. Using the current sensors, the charging station directly measures the current transfer at the grid connection point in order to then increase the solar power share of the charging current. In this case too, communication between the charging station and the at least one sensor usually takes place via wire or radio via a digital communication protocol, e.g. an RS485 bus of the WLAN.

With the approaches described above, satisfactory charging management is already possible. However, a disadvantage of the approaches described above is that a comparatively complex installation is often required for implementation. With wired data transmission, it is often comparatively large The distance between the charging station and the sensors and communication devices used, in particular the cabling, is often complex and prone to errors. With wireless solutions, there is no need for cabling. A disadvantage of radio transmission, however, is the limited radio range, which regularly makes data transmission prone to errors or even completely precludes it due to unfavorable spatial conditions, for example due to intermediate house walls between the sub-distributor arranged in the basement and the charging station arranged in the garage.

In addition, the implementation of the approaches described above is often made more difficult by the incompatibility of the various components involved with regard to data transmission, e.g. the communication protocol used. For example, a newly purchased charging station is often not compatible with existing components such as the PV inverter or existing electricity meters in terms of signal transmission, so that additional sensors have to be installed or the necessary communication between the existing components and the charging station can only be achieved via intermediate adapters (e.g. hardware adapters and/or software components for signal conversion or translation). On the other hand, the use of a higher-level communication device, e.g. a smart home control, requires - sometimes complex - system integration.

The invention is based on the object of providing an optimized charging management for charging an electric vehicle using means that can be implemented in a particularly inexpensive manner.

With regard to a method for charging an electric vehicle, this task is solved according to the invention by the features of claim 1. With regard to a charging control for an electric vehicle, the above task is solved according to the invention by the features of claim 9. Advantageous and partly inventive embodiments The invention is set out in the subclaims and the following description.

According to the invention, it is provided that a (vehicle-internal) default value of the charging current intensity or (electrical) charging power is specified in a time-varying manner by the charging controller installed in the electric vehicle and provided for the vehicle-internal control of the charging process. This default value is varied in particular continuously or in several stages. Because the default value for the charging current or charging power is specified according to the invention by the charging control of the electric vehicle, the use of vehicle-external charging management becomes unnecessary. The electric vehicle can thus be charged in a grid-friendly manner at a household socket or power socket of a normal local power distribution network in the same way as at a dedicated charging station.

If the electric vehicle is charged at a charging station and the charging control of the electric vehicle also receives a vehicle-external default value of the charging current or charging power from the charging station (in addition to the self-determined, vehicle-internal default value), the charging control of the electric vehicle limits Vehicle, the charging current or charging power is usually always set to the smaller of the two default values. However, it can also be provided within the scope of the invention that the charging control of the electric vehicle, when connecting it to a public or private charging station, gives the latter a priority with regard to the specification of the default value (in particular if the vehicle-external default value is determined by the charging station is specified in a sufficiently differentiated manner). In this case, the charging control of the electric vehicle optionally sets its own, vehicle-internal default value during such a charging process. For example, in an advantageous embodiment it is provided that the charging control of the electric vehicle sets the specification of its own default value when the electric vehicle is charged at a public fast charging station. In another advantageous application, the charging control also gives priority to the vehicle-external default value transmitted from a specific private charging station over the vehicle-internal default value.

wobei V den Vorgabewert, L die Ladekurve und t die Zeit repräsentiert. Alternativ kann die Ladekurve im Rahmen der Erfindung aber auch so definiert sein, dass sie nur den Verlauf des Vorgabewerts abbildet und mit letzterem in einer - z.B. linearen - Beziehung steht: $$\text{V}=\text{k}\cdot \text{L}\left(\text{t}\right),$$

wobei k für einen konstanten oder ebenfalls veränderlichen Parameter steht.The default value is preferably determined based on a charging curve stored in the electric vehicle, which is stored in particular in the form of a time-dependent mathematical function (i.e. a mathematical formula), in the form of a base point table or in a mixed form of base points and formula. Within the scope of the invention, the charging curve can directly reflect the default value of the charging current or charging power to be set: $$\text{v}=\text{L}\left(\text{t}\right),$$

where V represents the default value, L the charging curve and t the time. Alternatively, within the scope of the invention, the charging curve can also be defined in such a way that it only represents the course of the default value and has a - for example linear - relationship with the latter: $$\text{v}=\text{k}\cdot \text{L}\left(\text{t}\right),$$

where k stands for a constant or also variable parameter.

• - für unterschiedliche Wochentage,
• - für unterschiedliche Halbjahre, Trimester, Quartale oder Monate,
• - für jede der klassischen Jahreszeiten Frühjahr, Sommer, Herbst, Winter oder
• - für jeden Tag im Jahr

jeweils einen individuellen Tagesverlauf aufweist.Within the scope of the invention, the charging curve can be defined (exclusively) depending on the time of day (of a single day), so that the charging curve has the same shape on every day. If the charging curve is available as a reference point table, in this version it includes, for example, 24 points (ie one point per hour), 96 points (ie one point per quarter of an hour) or 1440 points (ie one point per minute). Alternatively, the charging curve can also cover a period of less than 24 hours. In this case, the charging curve is preferably only processed within a section of each day (eg only between 7 a.m. and 10 p.m.). Preferably, the charging curve is also variable on a time scale exceeding 24 hours, so that the charging curve, for example

• - for different days of the week,
• - for different half-years, trimesters, quarters or months,
• - for each of the classic seasons spring, summer, autumn, winter or
• - for every day of the year

each has an individual daily course.

The charging curve is preferably stored in the charging control itself. Alternatively, the charging curve can also be stored in a separate data memory, e.g. a memory card or the memory of an external control device of the electric vehicle (e.g. an on-board computer) and from there made available to the charging control during operation.

Controlling the default value based on the stored charging curve has the advantage that individually optimized charging management is possible without complex installation, in particular without the use of electricity meters or current sensors in the local power distribution and their data transmission connection to the electric vehicle. Interaction between the electric vehicle and an electricity meter or current sensor external to the vehicle is therefore preferably not provided for in the charging control according to the invention.

In a preferred embodiment of the invention, the charging curve is stored in such a way that it can be changed freely or within predetermined degrees of freedom and limits with the help of input means, in particular by a user or technician. The input means, e.g. a keyboard, can be integrated into the electric vehicle within the scope of the invention and thus be part of the latter. Alternatively, the input means are provided as part of a programming module external to the vehicle (i.e. not part of the electric vehicle). In a particularly advantageous embodiment, the input means are implemented in a software application for configuring the charging control (hereinafter referred to as “configuration app”), which can be installed in a device external to the vehicle (e.g. a smartphone, tablet or other computer). The input means can be implemented, for example, in a graphical user interface in which the charging curve can be drawn using a finger or a drawing pen.

The method according to the invention is used in a particularly advantageous application in order to ensure a particularly high proportion of solar and/or wind power in the charging current. The charging curve is specified in such a way that it is correlated with an average course of solar radiation and/or wind strength. The charging curve is preferably (but not necessarily) specifically adapted to the average (or historical) course of solar radiation and/or wind strength at the geographical location of the electric vehicle. This method variant is particularly advantageous if the electric vehicle is connected to a local power distribution into which a PV system or a wind turbine is connected. In terms of environmentally friendly charging, the charging curve adapted to the average solar radiation and/or wind strength also makes sense if the electric vehicle draws the charging power exclusively from the public power grid, as this improves the utilization of regional and regeneratively generated grid power.

The term “correlated” here generally means that the charging curve follows the average course of solar radiation and/or wind strength at the geographical location of the electric vehicle (in particular in a linear or non-linear relationship), i.e. a higher one with higher average solar radiation or wind strength Value and has a lower value when the average solar radiation or wind strength is lower. The charging curve can also change - depending on the geographical dependency of the charging curve - when the electric vehicle is moved.

• - für den Subkontinent (z.B. Westeuropa),
• - die Zeitzone,
• - das Land oder den Landesteil (z.B. Bundesstaat oder Verwaltungsbezirk), oder
• - die Stadt oder den Postleitzahlenbereich,

in dem bzw. der sich das E-Fahrzeug befindet, spezifisch ist. Alternativ hierzu wird die Ladekurve in einer bevorzugten Ausführung der Erfindung spezifisch für die konkreten geographischen Koordinaten des Standorts des E-Fahrzeugs bestimmt.The geographical location of the electric vehicle can be limited to varying degrees of precision within the scope of the invention. For example, the charging curve can be specified in different versions in such a way that

• - for the subcontinent (e.g. Western Europe),
• - the time zone,
• - the country or part of the country (e.g. federal state or administrative district), or
• - the city or postal code area,

in which the electric vehicle is located is specific. Alternatively, in a preferred embodiment of the invention, the charging curve is determined specifically for the specific geographical coordinates of the location of the electric vehicle.

In a particularly easy to implement, but still effective, embodiment of the invention, the charging curve is predetermined in such a way that it is correlated with the seasonally varying day length at the geographical location of the electric vehicle, i.e. follows the course of the seasonally varying day length. For example, the charging curve is predetermined in such a way that it has a non-zero default value for the charging current strength only during the day during a period of time that begins on each day a given period of time after the respective calendar sunrise time and ends a predetermined period of time before the respective calendar sunset time. The charging current is increased gradually (i.e. continuously or in several steps) to a peak value, particularly between the times of sunrise and sunset, and then gradually reduced again. In particular, charging starts with the minimum charging current that the electric vehicle allows.

Optionally, the height (in particular the peak value) of the charging curve is also adjusted during the day to adapt to the seasonally varying average values of solar radiation and/or wind strength. For example, the charging curve takes on higher values over the course of the day during the summer than during the winter.

In an advantageous embodiment of the invention, the default value is determined depending on at least one piece of information about a PV system, in particular the nominal power of the PV system, the inclination of the PV system, the geographical position of the PV system and/or the geographical orientation of the PV system PV system varies in terms of cardinal directions. Additionally or alternatively, the default value in this variant of the invention is varied depending on information about a wind turbine, in particular the nominal power of the wind turbine. This means that in applications in which the electric vehicle is also powered locally from a PV system or a wind system, the usable solar or wind power can be used particularly well to provide charging power.

This information about a specific PV or wind turbine is in particular part of an optionally provided home setting of the charging control, which can be activated manually by a user or is automatically activated by the charging control whenever the location of the electric vehicle matches a predetermined home location . In an extension of this concept, several home settings can be stored in the charging control and assigned to respective home locations in order to charge the electric vehicle at various frequently frequented locations (e.g. the vehicle user's home and work location) in a manner adapted to the local conditions . In an expedient embodiment of the invention, the above-mentioned information on a PV system and/or a wind system is taken into account when creating the charging curve (and thus in particular once when the electric vehicle is put into operation). In particular, this information can be entered in the above-mentioned configuration app, which then calculates the charging curve taking this information into account. Alternatively, the above-mentioned information about a PV system and/or a wind turbine can also be used to modify an independently calculated charging curve during operation of the electric vehicle in adaptation to the PV and wind turbine. In a further embodiment variant, a location-specific charging curve is only loaded onto the vehicle, e.g. through independent communication of the charging control with the Internet or via the user's electronic mobile device, when a charging process is started in the respective geographical area.

The above information allows a precise and individual adjustment of the charging curve in terms of its height and time of day distortion to the solar power supplied by a PV system. For example, it is taken into account that the maximum solar output occurs earlier or later in the day depending on the geographical orientation of the PV system if the solar radiation is undisturbed. Taking the inclination of the PV system into account allows the seasonal progression of average solar power generation to be reflected in the charging curve; For example, it is taken into account that with a highly inclined PV system the differences in summer and winter solar output are smaller than with a slightly inclined PV system.

• - Messdaten eines in das E-Fahrzeug integrierten oder mit dem E-Fahrzeug (drahtgebunden oder drahtlos) verbundenen Strahlungssensors bzw. Windsensors,
• - der gemessenen Netzspannung (insbesondere anhand von Messdaten eines Netzspannungssensors), und/oder
• - Prognosedaten eines Wetterdienstes

herangezogen.In a further advantageous embodiment of the invention, the default value is varied depending on information about the (current or predicted) actual solar radiation and/or depending on information about the (current or predicted) actual wind strength at the geographical location of the electric vehicle . In particular, information about the actual solar radiation or wind strength is provided

• - Measurement data from a radiation sensor or wind sensor integrated into the e-vehicle or connected to the e-vehicle (wired or wireless),
• - the measured mains voltage (in particular based on measurement data from a mains voltage sensor), and/or
• - Forecast data from a weather service

used.

The optional use of the mains voltage (i.e. the measurement data from the mains voltage sensor) as a control variable for setting the default value is based on the knowledge that the mains voltage fluctuates slightly with the local and regional electricity availability. It is recognized that the local or regional electricity availability is significantly influenced by weather-dependent electricity generation units, namely PV systems and wind turbines in the local electricity distribution or their surroundings, which manifests itself in measurable fluctuations in the grid voltage. Depending on the local and regional electricity generation infrastructure, i.e. the presence of PV systems or wind turbines in the local electricity distribution or their surroundings, time intervals with high solar radiation or high wind strength are recognized to be more or less pronounced in a slight increase in the grid voltage, while in time intervals With low solar radiation and low wind strength, the grid voltage drops slightly. This phenomenon is preferably used here to indirectly determine the actual solar radiation or wind strength by measuring the mains voltage and to control the charging process accordingly. In particular, the default value is increased when the mains voltage is comparatively high and reduced when the mains voltage is comparatively low.

In particular, forecast data from a weather service is automatically retrieved from the Internet by the electric vehicle.

In a possible embodiment of the invention, the forecast data is determined using the above-mentioned configuration app or a different app for a mobile device (e.g. smartphone or tablet) of a user of the e-vehicle and is always transmitted to the e-vehicle when the the respective app is connected to the electric vehicle, e.g. via Bluetooth; especially whenever the mobile device on which the app is installed is close to the electric vehicle. Here, not only a current forecast value (e.g. for the coming hour) is preferably transmitted, but also a long-term forecast that contains forecast data for several days, for example for every hour of the next 16 days. Whenever the respective app is reconnected to the electric vehicle, the long-term forecast stored in the electric vehicle is transferred with updated values. In a variant of this embodiment, an adapted charging curve is calculated using the app based on the forecast data. In this case - in addition to or instead of the raw forecast data - the charging curve adjusted based on the forecast is transferred to the e-vehicle when the mobile device is connected to the e-vehicle. An advantage of this embodiment is that the charging control of the electric vehicle itself can (and preferably will) be operated offline. In particular, the charging control is not equipped with means for connecting to the Internet, which enables the charging control to be implemented simply and inexpensively. A further advantage of this embodiment is that the computing capacity of the mobile device can be used to obtain the forecast data and, if necessary, to calculate the adapted charging curve. This allows a correspondingly smaller dimensioning of the computing power of the charging control of the electric vehicle. Alternatively, the forecast data is downloaded directly from the Internet by the charging controller or another control device in the electric vehicle.

The information about the actual solar radiation or wind strength can be used within the scope of the invention in combination with a stored charging curve or independently of it. In the former case, for example, the predetermined charging curve is raised/lowered or scaled depending on the information about the actual solar radiation or wind strength. In the latter case, no stored charging curve is used to adapt the default value of the charging current. Rather, the default value is only varied taking into account the information about the actual solar radiation or wind strength.

The charging control according to the invention is generally set up to carry out the method according to the invention described above. Embodiments of the method therefore correspond to corresponding embodiments of the charging control. Comments on variants of the method and their respective effects and advantages can be transferred accordingly to the charging control and vice versa.

The charging control is a structural unit that is assigned to the e-vehicle and in particular can be permanently installed or installed in the e-vehicle. It includes exemplary examples Formation of an electrical charging circuit, for example in the form of a controllable rectifier, which serves to convert the charging current supplied as alternating current into a direct current with adjustable voltage or current to be supplied to the vehicle battery. In an exemplary embodiment, the charging control further includes control logic for controlling the charging circuit.

In an expedient embodiment, the charging control comprises, in addition to an electronic unit that can be installed or installed in the electric vehicle, a software application (configuration app) which is intended and set up for configuring the control logic of the charging control (arranged in the vehicle), and which e.g. can be installed on a smartphone or computer. The smartphone or the computer are generally not part of the charging control according to the invention and are regularly manufactured and sold independently of the charging control. Rather, the smartphone or computer is only used by the charging controller as an external resource for computing power, storage space and communication services (similar to how the public power grid is only used by the charging controller as a resource for electrical power without becoming part of the charging controller). . The configuration app can be connected to the charging controller or any external control device of the electric vehicle, preferably via a wireless data transmission link (in particular via Bluetooth or mobile communications). For this purpose, the configuration app uses a corresponding transmitting and receiving unit on the smartphone or computer.

The charging control is set up to enable a charging process for charging an electric vehicle and to specify a (vehicle-internal) default value that varies over time, in particular continuously or in several stages. The charging control is preferably set up to determine the default value based on a charging curve stored in the electric vehicle, in particular in the form of a time-dependent mathematical function or base table.

As control logic, the charging controller preferably comprises a programmable component, e.g. a microprocessor or single-board computer, in which software (firmware) implementing the functions of the control logic is installed and ready to run. Alternatively, the control logic can also be formed by a non-programmable hardware circuit (e.g. in the form of an ASIC). Alternatively, the control logic can be formed by a combination of programmable and/or non-programmable components.

In an advantageous embodiment, the charging control comprises input means of the type described above, by means of which the charging curve can be changed. As described above, these input means are integrated either in the electric vehicle itself and/or in an external programming module (i.e. a programming device or, if applicable, the configuration app mentioned above).

In a further advantageous embodiment of the charging control, the charging curve is predetermined in such a way that it is correlated with an average (or historical) course of solar radiation and/or wind strength, in particular specifically for the geographical location of the electric vehicle. In an advantageous embodiment, the charging curve is correlated with the seasonally varying day length at the geographical location of the electric vehicle.

Preferably, the charging control includes an adaptation module that is set up to adjust the default value depending on at least one piece of information about a PV system, in particular the nominal power, the inclination, the geographical position and/or the geographical orientation of the PV system, and/or to vary depending on information about a wind turbine, in particular the nominal power of the wind turbine. The adaptation module is implemented either as a (hardware or software) component of the charging controller or an external control device in the electric vehicle or as a (software) component of the configuration app mentioned above.

Preferably, the charging control is set up to vary the default value depending on information about the (current or predicted) actual solar radiation and/or depending on information about the (current or predicted) actual wind strength at the geographical location of the electric vehicle . When a high radiation intensity (sunshine) is detected, the charging curve in particular is adjusted to a higher level than when the radiation intensity is low (cloud cover). Additionally or alternatively, if a high wind speed is detected, the charging curve is adjusted higher than when the wind speed is low.

In an advantageous embodiment, the charging controller is set up to use measurement data from a radiation sensor or wind sensor integrated into the e-vehicle or connected to the e-vehicle, a mains voltage sensor and/or forecast data from a weather service as information about the actual solar radiation or wind strength. Those mentioned above Sensors can be a separate component of the charging control according to the invention.

In an expedient embodiment of the invention, the charging controller or any other control device in the electric vehicle is equipped with communication electronics, for example a mobile radio, LAN and/or WLAN adapter, for wired or wireless data exchange with a remote server, in particular on the Internet equipped, e.g. to independently retrieve forecast data from a weather service.

The electric vehicle optionally includes a receiver for signals from a global positioning system (e.g. a GPS receiver). The charging control is set up to automatically determine the geographical location of the electric vehicle using the receiver mentioned. Alternatively, the charging control is set up to automatically determine the geographical location of the electric vehicle by communicating with a data transmission network (e.g. a mobile phone or WLAN network) using the receiver mentioned. Alternatively, within the scope of the invention, the geographical location of the e-vehicle can be automatically determined by the configuration app that may be present and transferred to the e-vehicle or taken into account when creating the charging curve.

The electric vehicle is preferably equipped with a real-time clock in order to determine the default value depending on the time of day and optionally the day of the week and/or the position of the current day in the year.

In an advantageous exemplary embodiment, the charging control uses the real-time clock to determine sunrise and sunset times using an annual calendar. Between these points in time, it calculates an estimate of the solar power share in the public power grid or - if the electric vehicle is in a designated home location - the solar power curve of a PV system connected to the home power installation, on which the charging is based. This means that the charging control of the electric vehicle knows the timing of the expected solar power and controls the charging current, for example between 6A and 16A and/or between single-phase charging and three-phase charging. As a result, a high solar power share of the charging current is achieved using simple means.

Communication between the electric vehicle and an electricity meter or other electricity measuring device in the local electricity distribution is not required in all of the exemplary embodiments described above and is therefore preferably not provided.

• 1 in einem schematischen Blockschaltbild ein Elektro-Fahrzeug (E-Fahrzeug), das über eine lokale Stromverteilung (hier beispielhaft eine elektrische Haustrominstallation) an ein öffentliches Stromnetz anschließbar ist, wobei eine Ladesteuerung des E-Fahrzeugs einen Vorgabewert der Ladestromstärke anhand einer hinterlegten, zeitabhängigen Ladekurve bestimmt, die mit dem durchschnittlichen Verlauf der Sonneneinstrahlung an dem geographischen Standort des E-Fahrzeugs korreliert ist,
• 2 in einem schematischen Blockschaltbild in größerem Detail die Ladesteuerung sowie ihre Verschaltung mit einem Bord-Computer und einer Batterie des E-Fahrzeugs,
• 3 in drei übereinander angeordneten, chronologischen Diagrammen, drei Ausschnitte der Ladekurve für drei verschiedene Tage im Jahr, nämlich für einen Tag im Sommer (oberes Diagramm), einen Tag im Frühjahr oder Herbst (mittleres Diagramm) und einen Tag im Winter (unteres Diagramm),
• 4 zur Veranschaulichung eines alternativen, mittels der Ladesteuerung durchgeführten Ladenverfahrens in drei übereinander angeordneten, chronologischen Diagrammen den zeitlichen Verlauf eines von einem Strahlungssensor des E-Fahrzeugs erfassten Messsignals (oberes Diagramm), eine in dem E-Fahrzeug hinterlegte, zeitabhängige Ladekurve (mittleres Diagramm), und den Verlauf des Vorgabewerts der Ladestromstärke (unteres Diagramm), und
• 5 in Darstellung gemäß 1 eine alternative Ladesituation, in der das Elektro-Fahrzeug zum Bezug des Ladestroms an eine Ladestation angeschlossen ist, die wiederum über die lokale Stromverteilung (hier die Haustrominstallation) an das öffentliche Stromnetz angeschlossen ist., und

Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. Show in it:

• 1 in a schematic block diagram, an electric vehicle (e-vehicle) that can be connected to a public power grid via a local power distribution (here, for example, an electrical house power installation), whereby a charging control of the e-vehicle determines a default value of the charging current based on a stored, time-dependent charging curve determined, which is correlated with the average course of solar radiation at the geographical location of the electric vehicle,
• 2 in a schematic block diagram in greater detail the charging control and its connection to an on-board computer and a battery of the electric vehicle,
• 3 in three chronological diagrams arranged one above the other, three sections of the charging curve for three different days of the year, namely for one day in summer (upper diagram), one day in spring or autumn (middle diagram) and one day in winter (lower diagram),
• 4 To illustrate an alternative charging process carried out using the charging control, in three chronological diagrams arranged one above the other, the time course of a measurement signal recorded by a radiation sensor of the electric vehicle (upper diagram), a time-dependent charging curve stored in the electric vehicle (middle diagram), and the course of the default value of the charging current (bottom diagram), and
• 5 in representation according to 1 an alternative charging situation in which the electric vehicle is connected to a charging station to obtain the charging current, which in turn is connected to the public power grid via the local power distribution (here the house power installation)., and

Corresponding parts and sizes are always provided with the same reference numbers in all figures.

1 shows a rough schematic of an electric vehicle (e-vehicle 2) in the form of a passenger car, which has a battery 4, a charging controller 6 and an on-board computer 8. During operation of the electric vehicle 2, the battery 4 feeds an electric drive motor (not shown) of the electric vehicle 2. The charging controller 6 integrated in the electric vehicle 2 is used to control a Charging process, in which the charging controller 6 supplies the battery 4 with an electrical charging current I _L with adjustable charging current or charging power. The charging controller 6 obtains this charging current I _L in the example 1 directly from a local power distribution, here for example the house power installation 10 of a private house. The house electricity installation 10 is in turn connected to a public power network 14 (namely a three-phase alternating current low-voltage network) at a network connection point 12. In addition to other electrical consumers (not shown), a photovoltaic system (PV system 16) is optionally connected to the house power installation 10.

To supply the charging current I _L to the battery 4, the charging controller 6 is connected via a (vehicle-internal) charging current line 18, on the one hand, to the battery 4, and, on the other hand, to a charging plug 20 of the electric vehicle 2.

For the charging process, the charging plug 20 of the electric vehicle 2 is in turn connected to the house power installation 10 via a charging cable 22. According to the example 1 For this purpose, the cable 22 is plugged directly into a socket 24 of the household power installation 10. The socket 24 is in particular a normal 1-phase household socket (eg according to CEE 7/4 - “Type F”) or a normal 3-phase power socket (according to IEC 60309).

The charging control 6 is supplied with the charging current I _L from the domestic power installation 10 in the form of a single- or three-phase alternating current. In a preferred embodiment, the charging controller 6 is designed to process both single-phase alternating current and three-phase alternating current, depending on the type of connection.

The charging control 6 includes according to 2 an electrical charging circuit which serves to convert the charging current I _L supplied as an alternating current with a mains voltage U into a direct current to be supplied to the battery 4 with an adjustable voltage (battery voltage U _B ) or current intensity. The charging circuit is formed in particular by a controllable rectifier 26, in particular a switching power supply. The charging controller 6 includes, in addition to the charging circuit, ie the rectifier 26, a control logic 28 for controlling the charging circuit.

The control logic 28 is preferably formed by a programmable electronic component, in particular a microprocessor, in which control software 30 is installed so that it can run. In an alternative embodiment, the control logic 28 is formed by a non-programmable hardware circuit, in particular in the form of an ASIC. The control logic 28 is in turn controlled, in particular activated and deactivated, by the higher-level on-board computer 8 of the electric vehicle 2. Additionally or alternatively, the control logic 28 receives status data from the on-board computer 8 about the operating status of the electric vehicle 2 and/or sends to the on-board computer 8 status data of the charging controller 6 (e.g. measured values of the battery voltage U _B and/or the current strength of the charging current I _L and/or the duration of the ongoing charging process). In addition, the charging controller 6 optionally uses a mobile radio transceiver 32 integrated into the on-board computer 8 or connected to the on-board computer 8 in order to exchange data with the Internet in a manner described in more detail below. To measure the current strength of the charging current I _L , the charging controller 6 further comprises a current sensor 34 connected to the charging current line 18.

During a charging process, the charging control 6 of the electric vehicle 2 is supplied with the charging current I _L from the house power installation 10 via the charging cable 22, which varies depending on availability and needs from a solar power I _S and generated by the PV system 16 a mains current I _N drawn from the power network 12 is fed.

The control logic 28 of the charging controller 6 initiates a charging process either at the request of a user or automatically when it connects the charging plug 20 to a suitable power source, e.g. B. the house power installation 10. For this purpose, the control logic 28 controls the rectifier 26 to output the rectified charging current I _L to the battery 4.

During the charging process, the control logic 28 regulates the current intensity of the charging current I _L (charging current intensity) as required. For this purpose, it basically varies the charging current intensity quasi-continuously (ie in many small steps) between a minimum value V _min (for example corresponding to a charging current intensity of 6A) and a time-varying default value V, so that the battery 4 is charged as quickly as possible without the risk of overloading, and it ends the charging process by switching off the rectifier 26 (and thus reducing the charging current to zero) when the battery 4 is charged. The control logic 28 generates the default value V in the example 1 until 3 also as a quasi-continuously variable variable that fluctuates between the minimum value V _min and a maximum value V _max (e.g. corresponding to a charging current of 16A). At times when no charging process is to take place, the default value V is preferably set differently to the value zero.

The control logic 28 determines the default value V based on a data memory Control logic 28 depending on the time t and the geographical location stored charging curve L (with L = L (t)), e.g. B. according to the formula $$\text{v}=\text{k}\cdot \text{L}\left(\text{t}\right).$$

Here, the parameter k stands for a configurable size, i.e. its value can be changed, but is constant during operation of the charging controller 6.

In a preferred embodiment of the charging control 6, the charging curve L is implemented as a reference point table, which has a specific assigned value for each point in time over the course of the year within the framework of a predetermined time resolution (e.g. at intervals of 5 minutes). The control logic 28, for example, queries a real-time clock of the electric vehicle 2 and successively reads value by value from the reference point table based on the time t output by this clock (e.g. every 5 minutes).

As in the diagrams of the 3 is illustrated, the charging curve L is predetermined such that it is correlated with the average course of solar radiation (and in particular also with the seasonally varying day length at the geographical location of the electric vehicle 2). Overnight, namely between the calendar time tu of each sunset and the calendar time t _A of the next sunrise, the charging curve L always has the value zero. Each predetermined period of time (e.g. 30 minutes) after sunrise, the charging curve L assumes a value other than _zero , in particular a predetermined minimum value _Lmin . Towards the middle of the day, the value of the charging curve L increases steadily. In the second half of the day, the value of the charging curve L then decreases steadily again, in particular until the minimum value L _min is reached. A predetermined period of time (e.g. 30 minutes) before sunset, the charging curve L then returns to the value zero and maintains this value throughout the night.

The charging curve L preferably has a daily course specifically tailored to that day for every day of the year. As can be seen from the diagrams of the 2 As can be seen, the charging curve L has longer charging periods (i.e. periods with a non-zero value) in summer (upper diagram) than in spring or autumn (middle diagram) and in winter (lower diagram), in particular in accordance with the seasonally varying day length. In addition, the charging curve during the winter only reaches lower peak values than in the summer due to the lower solar radiation over the course of the day.

In an expedient exemplary embodiment, the charging controller 6 downloads the charging curve L or a section thereof covering the duration of the charging process from an Internet server in a form adapted to the respective geographical location of the electric vehicle 2 before each charging process, using the mobile radio transceiver 32 of the electric vehicle 2 uses. These variants of the charging curve L downloaded from the Internet are each adapted to the average solar radiation and the average availability of solar power at the respective geographical location of the electric vehicle 2.

Optionally, a special home variant of the charging curve L for at least one designated home location of the electric vehicle 2, together with geographical information about the home location, can also be stored in the charging control 6 (if necessary). This home variant of the charging curve L is, for example, imported into a data memory of the control logic 28 when the e-vehicle 6 is put into operation and is activated by the control logic 28 during operation of the e-vehicle 2 whenever the e-vehicle 2 is at the assigned location Hometown is located. The home variant of the charging curve L is characterized, for example, by the fact that it individually takes into account individual properties of the house power installation 10 located at the home location, in particular the solar power contribution of the PV system 16.

The creation of the home variant of the charging curve L can be done by the control logic 28 (and thus in the electric vehicle 2) itself. In an alternative embodiment variant, the home variant of the charging curve L is calculated using a configuration app 36, which in the example shown is installed in a device external to the vehicle, for example a smartphone 38 of a technician or vehicle user that can be connected to the control logic 28 (wirelessly or wired). is.

1. a) Heimatort, z.B. in Form einer Postleitzahl
2. b) optional Nennleistung der PV-Anlage 16,
3. c) optional Neigung der PV-Anlage 16, und
4. d) optional geographische Ausrichtung der PV-Anlage 16 bezüglich der Himmelsrichtungen (insbesondere Azimutwinkel).

In this case, the configuration app 36 asks the technician or user, for example, to enter the following information:

1. a) Home town, e.g. in the form of a postal code
2. b) optional nominal power of the PV system 16,
3. c) optional inclination of the PV system 16, and
4. d) optional geographical alignment of the PV system 16 with respect to the cardinal points (in particular azimuth angles).

As an alternative to point a), the configuration app 36 is designed to determine the geographical location of the home town by accessing a GPS sensor on the smartphone 38 or evaluating the mobile to automatically determine the radio cell in which the smartphone 38 is registered.

Based on the specified home location, the configuration app 36 automatically downloads data about the seasonally varying day length and the average course of solar radiation at the home location for each day of the year by connecting to the Internet.

The configuration app 36 uses this data to create the home version of the charging curve L in such a way that the daily course of the charging curve L is adapted to the course of the average solar radiation for every day of the year.

If the user provides the data listed under b) to d) about the PV system 16, the charging curve L is modified by an adaptation module 42 - implemented here as part of the configuration app 36 - in accordance with the construction-related efficiency curve of the PV system 16. 3 shows an example of such a home variant of the charging curve L with a daily course that is distorted compared to the typical daily course of solar radiation. The maximum of the charging curve L is reached here every day in the first half of the day. This corresponds to the efficiency curve of a south-east facing PV system 16.

Optionally, the configuration app 36 is programmed in such a way that information b) to d) can be entered for several PV systems. In this case, the adaptation module 42 uses this information to calculate the average course of the total solar power supplied by the several PV systems and takes this size into account when creating the charging curve L.

As indicated above, the charging controller 6 optionally offers the possibility of storing its own charging curves L for several home locations (e.g. the vehicle user's place of residence and place of work) together with assigned geographical information about the location of the respective home location.

The charging curve L created in this way is then transferred from the configuration app 36 to the control logic 28 and stored there for later use in the operation of the electric vehicle 2. The configuration app 36 is then preferably separated from the electric vehicle 2 in terms of data transmission. When the e-vehicle 2 is in operation, a data transmission connection between the e-vehicle 2 and the configuration app 36 or other electronic components (outside the e-vehicle 2) is not required and is not regularly present.

As in 1 and 2 shown, the control logic 28 of the charging controller 6 is optionally connected to a radiation sensor 44, which is attached, for example, to a windshield of the electric vehicle 2. During operation of the electric vehicle 2, the radiation sensor 44 continuously measures the actual solar radiation at the location of the electric vehicle 2 and delivers a measurement signal M of the actual solar radiation to the control logic 28.

In one based on 4 In the illustrated embodiment of the charging control 6, the control logic 28 determines the default value V - in a manner similar to that described previously - based on a stored charging curve L, but also takes into account the time-dependent measurement signal M (M = M (t)) of the actual solar radiation: $$\text{M}\left(\text{t}\right)\cdot \text{L}\left(\text{t}\right)\to \text{v}$$

The information about the solar radiation at the location of the electric vehicle 2, and thus the information about the available solar power, is included in the implementation 4 obtained from the measurement signal M, through which the charging curve L is scaled depending on the actual solar radiation.

In 4 the interaction of the measurement signal M and the charging curve L to generate the default value V in the charging method described above is illustrated. From this representation it can be seen in particular that the default value V is not generated here, for example, as a quasi-continuous varying variable, but rather jumps in a few discrete steps between the minimum V _min and the maximum V _max (this discretization of the default value V, which is mathematically approximately corresponds to a rounding of the product M(t) · L(t) is indicated in the above formula by using an arrow instead of an equal sign). The default value V is also set to the value zero if the value of the measurement signal M falls below a threshold value M0.

The invention is particularly clear from the exemplary embodiments described above, but is not limited to these exemplary embodiments. Rather, further embodiments of the invention can be derived from the claims and the above description. In particular, the individual features of the charging control described in the above exemplary embodiments can also be combined with one another in a different way within the scope of the claims.

Reference symbol list

2

E-vehicle

4

battery

6

Load control

8th

On-board computer

10

House electricity installation

12

Network connection point

14

power grid

16

PV system

18

Junction box

20

Charging plug

22

Charging cable

24

Power outlet

26

rectifier

28

Control logic

30

Tax software

32

Cellular transceiver

34

Current sensor

36

Configuration app

38

Smartphone

42

Customization module

44

Radiation sensor

t

Time

tA

time (of sunrise)

tU

time (of sunset)

IL

charging current

IN

Mains power

IS

Solar power

L

Charging curve

Lmax

Maximum value

Lmin

Minimum value

M

measurement signal

M0

Threshold

v

Default value

Vmin

minimum

Vmax

maximum

Claims (17)

Method for charging an electric vehicle (2), wherein a default value (V) for the charging current strength or charging power of a charging current (IL ) obtained from the electric vehicle (2) is specified in a time-varying manner by a charging controller ( ₆ ) of the electric vehicle (2). . Procedure according to Claim 1 , wherein the default value (V) is determined based on a charging curve (L) stored in the electric vehicle (2), in particular in the form of a time-dependent mathematical function or base table. Procedure according to Claim 2 , wherein the charging curve (L) can be changed, in particular by means of input means of the charging control (6) or an external programming module. Procedure according to Claim 2 or 3 , wherein the charging curve (L) is predetermined such that it is correlated with the average course of solar radiation and / or wind strength, in particular specifically for the geographical location of the electric vehicle (6). Procedure according to one of the Claims 2 until 4 , whereby the charging curve (L) is predetermined such that it is correlated with the seasonally varying day length at the geographical location of the electric vehicle (6). Procedure according to one of the Claims 1 until 5 , wherein the default value (V) depends on at least one information about a photovoltaic system (16), in particular the nominal power of the photovoltaic system (16), the inclination of the photovoltaic system (16), the geographical position of the photovoltaic system (16) and / or the geographical Alignment of the photovoltaic system (16) with respect to the cardinal points, and/or depending on information about a wind turbine, in particular the nominal power of the wind turbine, is varied. Procedure according to one of the Claims 1 until 6 , wherein the default value (V) is varied depending on information about the actual solar radiation and / or depending on information about the actual wind strength at the geographical location of the electric vehicle (2). Procedure according to Claim 7 , whereby as information about the actual solar radiation or wind strength - measurement data from a radiation sensor (44) or wind sensor integrated into the electric vehicle (2) and connected to the charging control (6). - the measured mains voltage (U), and/or - forecast data from a weather service can be used. Charging control (6) for an electric vehicle (2), which is connected via a local power distribution (10). public power grid (14) can be connected in order to obtain a charging current (I _L ) for the electric vehicle (2), the charging controller (6) being set up to enable a charging process for charging an electric vehicle (2) and thereby a default value (V) of the charging current or charging power to vary over time. Charging control (6). Claim 9 , which is set up to determine the default value (V) based on a charging curve (L) stored in the electric vehicle (2), in particular in the form of a time-dependent mathematical function or base table. Charging control (6). Claim 10 , with input means by which the charging curve (L) can be changed. Charging control (6). Claim 10 or 11 , wherein the charging curve (L) is predetermined such that it is correlated with the average course of solar radiation and / or wind strength, in particular specifically for the geographical location of the electric vehicle (2). Charging control (6) according to one of the Claims 10 until 12 , wherein the charging curve (L) is predetermined such that it is correlated with the seasonally varying day length at the geographical location of the electric vehicle (2). Charging control (6) according to one of the Claims 9 until 13 , with an adaptation module (42) which is set up to determine the default value (V) depending on at least one piece of information about a photovoltaic system (16), in particular the nominal power of the photovoltaic system (16), the inclination of the photovoltaic system (16), the geographical To vary the position of the photovoltaic system (16) and/or the geographical orientation of the photovoltaic system (16) with respect to the cardinal points, and/or depending on information about a wind turbine, in particular the nominal power of the wind turbine. Charging control (6) according to one of the Claims 9 until 14 , which is designed to vary the default value (V) depending on information (M) about the actual solar radiation and / or depending on information about the actual wind strength at the geographical location of the electric vehicle (2). Charging control (6). Claim 15 , which is set up to provide information about the actual solar radiation or wind strength - a measurement signal (M) from a radiation sensor (44) or wind sensor integrated into the electric vehicle (2) and connected to the charging control (6), - the measured mains voltage ( U), and/or - to use forecast data from a weather service. Electric vehicle (2) with a charging control (6) according to one of the Claims 9 until 16 .

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