DE102021213626A1 - Optimized charging management for a charging station - Google Patents

Abstract

A device (2) for charging an electric vehicle (4) and a method for operating the same are specified. The device (2) comprises a charging station (6) which can be connected directly or indirectly via a local power distributor (8) to a public power grid (12) in order to supply a charging current (IL) with a specific default value (V) of the charging current strength for the To provide electric vehicle (4). The default value (V) is specified in a time-varying manner.

Description

The invention relates to a method for operating a charging station for charging an electric vehicle (e-vehicle for short) and to a device for charging an electric vehicle that includes such a charging station.

A charging station of the type mentioned above can be connected to a public power grid either directly or indirectly via a local power distribution system in order to provide charging current for the electric vehicle. The charging station enables the charging process (i.e. the output of the electrical charging current) by communicating with a charging controller of the electric vehicle and specifies a default value for the current strength of the charging current. The default value defines the maximum charging current that the e-vehicle can call up. Within the framework of this default value, the charging controller of the e-vehicle then controls the charging current actually drawn during the charging process. Here and in the following, "local power distribution" refers to the electrical installation separated from the public power grid by a grid connection point, e.g. The local power distribution thus includes those electrical lines and consumers as well as any existing storage and / the power generation units that are located on this side of the grid connection point from the point of view of the charging station and thus do not belong to the public power grid.

The invention relates primarily to a charging station that outputs the charging current as a one- to three-phase alternating current. Such charging stations are mainly used in the private sector or in parking lots or parking garages of companies or shops and are designed, for example, as wall-mounted "wall boxes" or as charging stations standing on the floor.

Previous charging stations usually release the charging process as soon as the e-vehicle to be charged is connected to the charging station. The default value of the charging current can often be set at the charging station or in the electric vehicle or by means of an app acting on the charging station or the electric vehicle. In these cases, the e-vehicle is charged as a function of a specified maximum current or power.

In the case of a charging station in particular, which is used in a private house equipped with a photovoltaic system (PV system), there is a strong need to draw the charging current for the e-vehicle as much as possible from the obtain excess power from the PV system. The proportion of the solar power generated by the PV system that is used for personal use (i.e. the house electricity requirement and charging the e-vehicle) should thus be increased and a feed-back of the solar power into the public power supply grid (supply grid or: grid for short) should be avoided as far as possible. Furthermore, feeding the charging current from the mains should be avoided or at least largely reduced.

In order to achieve this goal, charging stations optimized for solar power are already being used today. Such charging stations either have a digital input in order to request performance data from the PV system via a communication device and then regulate the charging power, or are digitally regulated by an interposed energy controller. This energy control usually accesses data from the PV inverter or a smart meter (i.e. an electricity meter set up to send the measurement data collected). 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. Communication between the PV inverter or the smart meter on the one hand and the charging station on the other is either wired, e.g. via an RS485 bus, or wireless, e.g. via WLAN. Sometimes the charging station and the PV inverter or smart meter are integrated into a smart home installation.

Also known are charging stations sold in combination with one or more current sensors. 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, the communication between the charging station and the at least one sensor usually takes place by wire or by radio using a digital communication protocol, e.g. an RS485 bus of the WLAN.

Satisfactory charge management is already possible with the approaches described above. A disadvantage of the approaches described above, however, is that the implementation often requires a comparatively complex installation. In the case of wired data transmission, due to the often comparatively large distance between the charging station and the sensors and communication devices used, the cabling in particular is regularly complex and error-prone. With wireless solutions, there is no need for cabling. A disadvantage of radio transmission is the limited radio range regularly makes the data transmission error-prone or even completely excludes it due to unfavorable spatial conditions, eg due to temporarily stored 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 required 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) can be produced. On the other hand, the use of a higher-level communication device, e.g. a smart home control, requires - sometimes complex - system integration.

The object of the invention is to provide optimized charging management for charging an electric vehicle with means that can be implemented particularly inexpensively.

With regard to a method for operating a charging station provided for charging an electric vehicle, this object is achieved according to the invention by the features of claim 1. With regard to a device for charging an electric vehicle, the above object is achieved by the features of claim 9. Advantageous and partly for Perceived inventive embodiments of the invention are set forth in the subclaims and the description below.

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.According to the invention, it is provided that the default value is specified to vary over time. The default value is varied in particular continuously or in several stages. The default value of the charging current is preferably determined using a stored charging curve, which is stored in particular in the form of a time-dependent mathematical function (i.e. a mathematical formula), in the form of a support point table or in a mixed form of support points and formula. Within the scope of the invention, the charging curve can directly reflect the default value of the charging current to be set: $$\text{V}=\text{L}\left(\text{t}\right),$$

where V represents the default value, L the charge 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 depicts the progression of the default value and is in a relationship, e.g. linear, with the latter: $$\text{V}=\text{k}\cdot \text{L}\left(\text{t}\right),$$

where k stands for a constant or 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) as a function of 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 base table, in this embodiment it comprises, 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 processed only within a section of each day (eg only between 7 a.m. and 10 p.m.). However, the charging curve is preferably 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 of spring, summer, autumn, or winter
• - for every day of the year

each has an individual course of the day.

The charging curve is preferably stored in the charging station itself. Alternatively, the charging curve can also be stored in an external data memory (i.e. not belonging to the charging station), e.g. a memory card or the memory of an external control device (e.g. a central computer or cloud server) and made available from there to the charging station during operation become.

Controlling the default value for the charging current 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 and their data transmission connection to the charging station. An interaction of the charging station with an electricity meter or current sensor is therefore in the inventions dung proper charging station preferably not provided.

In a preferred embodiment of the invention, the charging curve is stored in such a way that it can be changed freely or within specified degrees of freedom and limits using input means, in particular by a user or technician. The input means, e.g. a keyboard, can be integrated into the charging station within the scope of the invention and thus be a part of the latter. Alternatively, the input means are provided as part of an external programming module (thus again not belonging to the charging station). In a particularly advantageous embodiment, the input means are implemented in a software application for configuring the charging station (hereinafter “configuration app” for short), which can be installed on a smartphone, tablet or computer. The input means can be implemented in a graphical user interface, for example, in which the charging curve can be drawn using a finger or a 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. In this case, the charging curve is specified in such a way that it is correlated with an average course of the solar radiation and/or wind speed. In this case, the charging curve is preferably (but not necessarily) specifically adapted to the average (or historical) course of the solar radiation and/or wind strength at the geographic location of the charging station. This variant of the method is particularly advantageous when the charging station is connected to a local power distribution system into which a PV system or a wind power plant is connected. In terms of environmentally friendly charging, the charging curve adapted to the average solar radiation and/or wind speed is also useful if the charging station draws the charging current exclusively from the public electricity grid, as this improves the utilization of the regionally and regeneratively generated grid electricity.

• - 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 die Ladestation befindet, spezifisch ist. Alternativ hierzu wird die Ladekurve in einer bevorzugten Ausführung der Erfindung spezifisch für die konkreten geographischen Koordinaten des Standorts der Ladestation bestimmt.The term "correlated" here generally means that the charging curve follows the average course of the solar radiation and/or wind strength at the geographic location of the charging station (in particular in a linear or non-linear relationship), i.e. a higher value and higher average solar radiation or wind strength has a lower value with lower average solar radiation or wind force. The geographic location of the charging station can be delimited with varying degrees of accuracy within the scope of the invention. For example, the charging curve can be specified in different versions in such a way that it

• - for the subcontinent (e.g. Western Europe),
• - the time zone,
• - the country or part of the country (e.g. state or county), or
• - the city or postcode area,

in which the charging station is located. As an alternative to this, in a preferred embodiment of the invention, the charging curve is determined specifically for the concrete geographic coordinates of the location of the charging station.

In a particularly easy to implement but nevertheless effective embodiment of the invention, the charging curve is specified in such a way that it is correlated with the seasonally varying length of days at the geographic location of the charging station, ie it follows the course of the varying length of days depending on the season. For example, the charging curve is specified such that it has a non-zero default value for the charging current only during the day during a period that begins 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 successively (i.e. continuously or in several steps) to a peak value, in particular between the times of sunrise and sunset, and then gradually reduced again. In particular, charging starts with a minimal charging current.

Optionally, the height (in particular the peak value) of the charging curve during the day is adjusted to the seasonally varying average values of solar radiation and/or wind strength. For example, the charging curve assumes 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 of the charging current depends 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 geographic position of the PV system and/or the geographic Alignment of the PV system with respect to the cardinal points varies. Additionally or alternatively, the default value in this variant of the invention depending on an indication of a wind turbine, in particular the nominal power of the wind turbine, varies. As a result, in applications in which the charging station is also supplied locally from a PV system or a wind system, the usable solar or wind power can be used particularly well to provide the charging current.

Preferably, the above-mentioned information about a PV system and/or a wind system is taken into account when creating the charging curve (and thus in particular once before the charging station is put into operation). For example, this information can be entered in the aforementioned 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 system can also be used in order to modify a charging curve calculated independently of this during operation of the charging station to adapt it to the PV system.

The above information allows a precise and individual adjustment of the charging curve in terms of its level and daily distortion to the solar power supplied by a PV system. For example, it is taken into account that the maximum of the solar output occurs earlier or later in the course of the day, depending on the geographic orientation of the PV system with undisturbed solar radiation. In turn, taking into account the inclination of the PV system allows the seasonal course of the average solar power generation to be mapped in the charging curve; for example, it is taken into account that the differences between summer and winter solar power are smaller with a strongly inclined PV system than with a slightly inclined PV system.

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

herangezogen. Da Ladestationen oft unter freiem Himmel oder zumindest in der Nähe von Außenbereichen (z.B. in einer Garage oder einem Carport) installiert werden, ist die datenübertragungstechnische Verbindung der Ladestation zu Strahlungs- oder Windsensoren oft wesentlich einfacher und störungs-unanfälliger zu realisieren als die Verbindung zu Stromzählern oder Stromsensoren, die in bekannter Weise an dem Netzverknüpfungspunkt oder Unterverteiler der lokalen Stromverteilung (insbesondere der Hausstrominstallation) angeordnet sind. In einer vorteilhaften Ausführungsform werden ein Strahlungssensor und/oder ein Windmesser unmittelbar in die Ladestation integriert.In a further advantageous embodiment of the invention, the default value of the charging current intensity 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 geographic location of the charging station . Information about the actual solar radiation or wind speed is used in particular

• - Measurement data from a radiation sensor or wind sensor integrated into the charging station or connected to the charging station (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. Since charging stations are often installed in the open air or at least in the vicinity of outdoor areas (e.g. in a garage or carport), the data transmission connection of the charging station to radiation or wind sensors is often much easier and less susceptible to interference than the connection to electricity meters or current sensors, which are arranged in a known manner at the network connection point or sub-distributor of the local power distribution (in particular the home power installation). In an advantageous embodiment, a radiation sensor and/or an anemometer are integrated directly into the charging station.

The optional use of the mains voltage (i.e. the measurement data of the mains voltage sensor) as a control variable for setting the default value of the charging current is based on the knowledge that the mains voltage fluctuates slightly with the local and regional power availability. As is well known, the local or regional power availability is significantly influenced by weather-dependent power generation units, namely PV systems and wind turbines in the local power distribution or their surroundings, which is reflected in measurable fluctuations in the grid voltage. Depending on the local and regional power generation infrastructure, i.e. the presence of PV systems or wind turbines in the local power 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 grid voltage, while in time intervals with low solar radiation and low wind speed, the mains voltage drops slightly. This phenomenon is preferably used here to indirectly determine the actual solar radiation or wind speed by measuring the mains voltage and to control the charging process accordingly. In particular, the default value of the charging current intensity is increased when the mains voltage is comparatively high and reduced when the mains voltage is comparatively low. Compared to known methods in which the charging current is controlled as a function of the data from electricity meters or current sensors, the variant of the invention described above has the advantage that the mains voltage can be measured in the charging station itself or in the immediate vicinity of it (and preferably also takes place), so that a complex installation is not necessary (and in particular not available).

In an advantageous embodiment of the invention, the course of the mains voltage is recorded continuously or at least over a longer period of time by the charging station or an external control unit. Provided this recording by the external control device that may be present, this is preferably arranged in the local power distribution system, in particular in the vicinity of the charging station in terms of circuitry. An average daily course of the mains voltage is determined for the location of the charging station by averaging the measured mains voltage with a resolution based on the time of day and, if necessary, additional smoothing over time. During operation of the charging station, the default value of the charging current intensity is varied as a function of the deviation of a currently measured value of the mains voltage from the value to be expected based on the average course of the day. The default value is increased in particular when the currently measured mains voltage is above the value to be expected for the respective time of day. The default value is reduced accordingly if the currently measured mains voltage is below the value to be expected for the respective time of day.

In particular, forecast data from a weather service are retrieved automatically from the charging station or an external control unit from the Internet.

In a particularly advantageous 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 charging station and is always transmitted to the charging station when the respective app with connected to the charging station, e.g. via Bluetooth; in particular whenever the mobile device on which the app is installed is in the vicinity of the charging station, or when the user uses the app to operate the charging station. In this case, preferably not only a current prognosis value (e.g. for the coming hour) is transmitted, but also a long-term prognosis which contains prognosis data for several days, for example for each hour of the next 16 days. Whenever the respective app is reconnected to the charging station, the long-term forecast stored in the charging station is overwritten 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 on the basis of the forecast is transmitted to the charging station when the mobile device is connected to the charging station. A major advantage of this embodiment is that the charging station itself can (and preferably will) be operated offline. In particular, the associated charging station is not equipped with means for connecting the electronic control system to the Internet, which enables the charging station to be implemented in a simple and uncomplicated manner. A further advantage of this embodiment lies in the fact that the computing capacity of the mobile terminal device can be used to obtain the prognosis data and, if necessary, to calculate the adapted charging curve. This allows a correspondingly smaller dimensioning of the computing power of the control electronics of the charging station.

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

• - ein weitere Ladestation, die mit der ersten Ladestation Daten austauscht,
• - ein übergeordnetes Steuergerät, das neben der (ersten) Ladestation optional mindestens eine gegebenenfalls vorhandene weitere Ladestation ansteuert,
• - ein Programmiergerät, z.B. in Form einer Fernsteuerung, zur Konfiguration der Ladestation,
• - einen externen Strahlungssensor,
• - einen externen Windsensor und/oder
• - einen Netzspannungssensor.

In simple embodiments of the invention, the device according to the invention for charging an electric vehicle consists exclusively of the charging station. In more complex versions of the invention, the device includes at least one peripheral device, for example, in addition to this (first) charging station

• - another charging station that exchanges data with the first charging station,
• - a higher-level control unit, which, in addition to the (first) charging station, optionally controls at least one other charging station that may be present,
• - a programming device, e.g. in the form of a remote control, for configuring the charging station,
• - an external radiation sensor,
• - an external wind sensor and/or
• - a mains voltage sensor.

In a particularly preferred embodiment, the device includes a software application (configuration app) in addition to the charging station, which is provided and set up for configuring the charging station and which can be installed on a smartphone or computer. The smartphone or the computer are usually not part of the device according to the invention and are regularly manufactured and sold independently of the device. Rather, the smartphone or computer is only used by the institution as an external resource for computing power, storage space and communications tion services (similar to how the utility grid is used by the facility only as a resource for electrical power without becoming a part of the facility). The configuration app can be connected to the charging station or an external control unit that may be present in the device, preferably via a wireless data transmission path (in particular using Bluetooth or mobile communications). The configuration app uses a corresponding transmitter and receiver unit on the smartphone or computer for this purpose.

The device 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 device. Statements on variants of the method and their respective effects and advantages can be transferred accordingly to the device, and vice versa.

Specifically, the device includes a charging station of the type described above, which can be connected to a public power grid either directly or indirectly via a local power distribution system (in particular an electrical domestic power installation) in order to provide charging current for electric vehicles. The charging station includes control electronics that are set up to enable a charging process for charging an electric vehicle and to specify a default value for the charging current intensity that varies over time, in particular that varies continuously or in a number of stages. The electronic control system is preferably set up to determine the default value of the charging current intensity using a charging curve stored in the charging station or an external data memory, in particular in the form of a time-dependent mathematical function or interpolation point table.

The control electronics of the charging station preferably includes a programmable component, e.g. a microprocessor or a single-board computer, in which software (firmware) that implements the functions of the control electronics is installed to run. As an alternative to this, the control electronics can also be formed by a non-programmable hardware circuit (e.g. in the form of an ASIC). Again alternatively, the control electronics can be formed by a combination of programmable and/or non-programmable components.

In an advantageous embodiment, the device includes 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 charging station itself and/or in an external programming module (i.e. a programming device or possibly the configuration app mentioned above).

In a further advantageous embodiment of the device, the charging curve is specified in such a way that it is correlated with an average (or historical) course of solar radiation and/or wind strength, in particular specific to the geographic location of the charging station. In an advantageous embodiment, the charging curve is correlated with the seasonally varying day length at the geographic location of the charging station.

The device preferably includes an adjustment module that is set up to adjust the default values for the charging current depending on at least one piece of information about a PV system, in particular the nominal power, the inclination, the geographic position and/or the geographic orientation of the PV system, and /or to vary depending on an indication of a wind turbine, in particular the nominal power of the wind turbine. The adjustment module is optionally implemented as a (hardware or software) component of the charging station, in particular the control electronics, or an external control device or as a (software) component of the configuration app mentioned above.

The control electronics of the charging station are preferably set up to set the default value of the charging current 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 geographic location of the charging station to vary. If a high radiation intensity (sunshine) is detected, the charging curve in particular is adjusted higher than with low radiation intensity (cloudy weather). Additionally or alternatively, if a high wind speed is detected, the charging curve is adjusted higher than if the wind speed is low. Within the scope of the invention, this function can alternatively also be implemented in an external (i.e. not belonging to the charging station) control unit.

In an advantageous embodiment, the control electronics or the external control unit are set up to use measurement data from a radiation sensor or wind sensor integrated into the charging station or connected to the charging station, a mains voltage sensor and/or forecast data from a weather service as information about the actual solar radiation or wind force pull. The sensors mentioned above can be a separate part of the device according to the invention. Alternatively, within the scope of the invention, the control electronics can also access data from external sensors, for example a wind sensor and/or radiation sensor of a smart home system or an awning control, etc.

In an expedient embodiment of the invention, the charging station or an external control unit that may be present in the device 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. e.g. to independently call up forecast data from a weather service.

The charging station further optionally comprises a receiver for signals from a global positioning system (e.g. a GPS receiver). The control electronics are set up to automatically determine the geographic location of the charging station by means of the named receiver. Alternatively, the control electronics are set up to automatically determine the geographic location of the charging station by communicating with a data transmission network (e.g. a mobile radio or WLAN network) using the named receiver. Alternatively, the geographical location of the charging station can also be stored manually (e.g. using the above configuration app) in the control electronics within the scope of the invention or automatically determined by the configuration app that may be present and transmitted to the charging station or when creating the charging curve taken into account.

The charging station 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 of the year.

In an advantageous exemplary embodiment, the control electronics of the charging station use the real-time clock to determine sunrise and sunset times using an annual calendar. Between these points in time, it calculates an estimate for the solar current curve of a connected PV system, which the charge is based on. The charging station thus knows the timing of the solar power to be expected and controls the charging current, e.g. between 6A and 16A and/or between 1-phase charging and 3-phase charging. As a result, a high proportion of solar power in the charging current is achieved without the need for installing power meters in the local power distribution and without the communication of these power meters with the charging station.

Communication between the charging station and an electricity meter or other electricity measuring device is not necessary in any of the exemplary embodiments described above and is therefore preferably not provided either.

In all of the above-described embodiments of the invention, the charging station has a charging cable (permanently connected to the charging station) for an electric vehicle to be charged or a connection socket (socket) for connecting a charging cable of an electric vehicle to be charged.

• 1 in einem schematischen Blockschaltbild eine Einrichtung zum Laden eines Elektro-Fahrzeugs (E-Fahrzeug), mit einer Ladestation, die über eine lokale Stromverteilung (hier beispielhaft eine elektrische Haustrominstallation) an ein öffentliches Stromnetz anschließbar ist, wobei die lokale Stromverteilung eine Photovoltaikanlage (PV-Anlage) umfasst, wobei die Ladestation einen Vorgabewert der Ladestromstärke anhand einer hinterlegten, zeitabhängigen Ladekurve bestimmt, die mit dem durchschnittlichen Verlauf der Sonneneinstrahlung an dem geographischen Standort der Ladestation korreliert ist,
• 2 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),
• 3 in Darstellung gemäß 1 eine weitere Ausführungsform der Einrichtung, mit einem Strahlungssensor zur Erfassung eines Messwerts der tatsächlichen Sonneneinstrahlung am Standort der Ladestation, wobei die Steuereinheit der Ladestation den Vorgabewert der Ladestromstärke anhand dieses Messwerts einstellt, und
• 4 in drei übereinander angeordneten, chronologischen Diagrammen den zeitlichen Verlauf eines von dem Strahlungssensor der Einrichtung gemäß 3 erfassten Messsignals (oberes Diagramm), eine in der Ladestation hinterlegte, zeitabhängige Ladekurve (mittleres Diagramm), und den Verlauf des Vorgabewerts der Ladestromstärke (unteres Diagramm).

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, a device for charging an electric vehicle (e-vehicle), with a charging station that can be connected to a public power grid via a local power distribution (here, for example, an electrical house power installation), the local power distribution being a photovoltaic system (PV System), wherein the charging station determines a default value of the charging current based on a stored, time-dependent charging curve, which is correlated with the average course of the solar radiation at the geographic location of the charging station,
• 2 in three chronological diagrams arranged one above the other, three sections of the charging curve for three different days of the year, namely for a day in summer (top diagram), a day in spring or autumn (middle diagram) and a day in winter (bottom diagram),
• 3 in representation according to 1 a further embodiment of the device, with a radiation sensor for detecting a measured value of the actual solar radiation at the location of the charging station, with the control unit of the charging station setting the default value of the charging current based on this measured value, and
• 4 in three chronological diagrams arranged one above the other, the course over time of one of the radiation sensors of the device 3 recorded measurement signal (upper diagram), a time-dependent charging curve stored in the charging station (middle diagram), and the course of the default value of the charging current (lower diagram).

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

1 shows a device 2 for charging an electric vehicle (electric vehicle 4). The device 2 includes a charging station 6, in particular in the form of a wall-mounted wall box. In the example shown, the charging station 6 is integrated into an electrical domestic power installation 8, which in turn is connected to a grid connection point 10 to a public power grid 12 (namely a three-phase AC low-voltage grid). In addition to the charging station 6 and other electrical consumers (not shown in detail), a photovoltaic system (PV system 14) is connected to the domestic power installation 8 .

The charging station 6 includes a connection socket 16 (i.e. a socket, in particular according to IEC 62196 Type 2) to which a charging cable 18 of the electric vehicle 4 with a corresponding charging plug 20 can be connected. As an alternative to the connection socket 16, the charging station 6 can also be provided with a permanently attached charging cable.

In addition to the junction box 16, the charging station 6 includes an electrical circuit breaker 22, which can be switched into a main power line 24 of the charging station 6 connecting the house power installation 8 to the junction box 16 in order to release or block a charging current I _L to be supplied to the electric vehicle 4.

The charging station 6 also includes control electronics 26, which is formed, for example, by a microcontroller or a single-board computer. The functions of the electronic control system 26 described in more detail below are implemented in the form of software (firmware 28) that is installed in the electronic control system 26 and is capable of running. The electronic control system 26 is connected to the junction box 16 and the circuit breaker 22 via data lines 30 and 32 .

The control electronics 26 also include a transmitting and receiving unit (transceiver 34), which is only indicated, which enables wireless communication between the control electronics 26 and other electronic devices, e.g. by means of Bluetooth.

During operation, the charging station 6 supplies the electric vehicle 4 that is to be charged and is connected to the charging station 6 by means of the charging cable 18 for this purpose with the charging current I _L , which, depending on availability and requirements, can be varied from a solar current I generated by the PV system 14 _S and a mains current I _N drawn from the mains 12 .

The electronic control unit 6 initiates a charging process at the request of a user or when the connected electric vehicle 4 is recognized by firstly opening the circuit breaker 22 by appropriate activation via the data line 32 and secondly by communicating with a charging controller of the electric vehicle 4 (via the data line 30, the junction box 16 and the charging cable 18) enables the charging process. In this case, the electronic control unit 26 also outputs a default value V to the charging controller of the electric vehicle 4 , which specifies the maximum charging current strength of the charging current I _L to be drawn from the charging station 6 by the electric vehicle 4 . The default value V is set by the electronic control system 26 in the example 1 and 2 as a quasi-continuous variable (ie in many small steps) between a minimum value L _min (eg corresponding to a charging current of 6A) and a maximum value L _max (eg corresponding to a charging current of 16A). In times when no charging process should take place, the charging curve L preferably has the value zero.

The electronic control unit 26 determines the default value V based on a charging curve L (with L=L(t)), z. B. according to the formula $$\text{V}=\text{k}\cdot \text{L}\left(\text{t}\right).$$

Here, the parameter k stands for a variable that is configurable, that is, variable in terms of its value, but constant during operation of the charging station 6 .

In a preferred embodiment of the device 2, the charging curve L is implemented as a support point table which has a specific assigned value for each point in time in the course of the year within the framework of a predetermined time resolution (e.g. at intervals of 5 minutes). The electronic control unit 26 has, for example, a real-time clock and uses the time t output by this clock (e.g. every 5 minutes) to successively read value for value from the interpolation point table.

As in the diagrams of 2 is illustrated, the charging curve L is specified such that it is correlated with the average course of the solar radiation (and here in particular with the seasonally varying length of the day at the geographic location of the charging station 6). Over night, namely between the calendar point in time tu of each sunset and the calendar point in time t _A of the next sunrise, the charging curve always has the value zero. In each case a predetermined period of time (of, for example, 30 minutes) after sunrise, the charging curve L assumes a value other than zero, in particular the predetermined minimum value L _min . 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 assumes the value zero again and maintains this value throughout the night.

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

To create the charging curve L, the device 2 has a software application (hereinafter configuration app 36) in addition to the charging station 4, which is installed on a smartphone 38 in the example shown. Unlike the configuration app 36, the smartphone 38 is not part of the device 2, but is used by it only as an external resource for computing power, storage space and communication services.

Before the charging station 6 is put into operation, the configuration app 36 is connected to the firmware 28 of the control electronics 26 via a particularly wireless data transmission path 40 (preferably by means of Bluetooth). In this case, the configuration app 36 accesses a corresponding transmission and reception unit of the smartphone 38 , which establishes a data transmission connection to the transceiver 34 of the charging station 6 .

The creation of the charging curve L can be started by a user (in particular a technician or owner of the charging station 6) interacting with the configuration app 36 .

1. a) geographischer Standort der Ladestation 6, z.B. in Form einer Postleitzahl
2. b) optional Nennleistung der PV-Anlage 14,
3. c) optional Neigung der PV-Anlage 14, und
4. d) optional geographische Ausrichtung der PV-Anlage 14 bezüglich der Himmelsrichtungen (insbesondere Azimutwinkel).

In this case, the configuration app 36 prompts the user to enter the following information:

1. a) geographic location of the charging station 6, for example in the form of a zip code
2. b) optional rated power of the PV system 14,
3. c) optional inclination of the PV system 14, and
4. d) optional geographic orientation of the PV system 14 with respect to the cardinal points (in particular azimuth angle).

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

Based on the geographical location, the configuration app 36 automatically downloads data on the seasonally varying length of days and the average course of the solar radiation at the location of the charging station 6 for each day of the year by connecting to the Internet. This data is made available, for example, on a server belonging to the manufacturer of the device 2 or obtained from publicly accessible sources.

The configuration app 36 uses this data to create 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 each day of the year.

If the user enters the data listed under b) to d) about the PV system 14, 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 14. 2 shows an example of the charging curve L with a distorted course of the day, in which the maximum of the charging curve L is already reached in the first half of each day. This corresponds to the efficiency curve of a south-east facing PV system 14.

The configuration app 36 is optionally programmed in such a way that the information b) to d) can be entered for a number of PV systems. In this case, the adjustment module 42 uses this information to calculate the average progression of the total solar current supplied by the multiple PV systems and takes this variable into account when creating the charging curve L.

The charging curve L created in this way is then transmitted by the configuration app 36 via the data transmission path 40 to the control electronics 26 and stored there for later use when the charging station 6 is in operation. The configuration app 36 is then preferably separated from the charging station 6 in terms of data transmission. When the charging station 6 is in operation, a data transmission connection between the charging station 6 and the configuration app 36 or other electronic components (apart from the electric vehicle 4) is not required and is also generally not available.

This in 3 The illustrated exemplary embodiment of the device 2 corresponds to the device 2, unless otherwise described below 1 . However, the device 2 according to 3 an additional radiation sensor 44, which continuously measures the actual solar radiation at the location of the charging station 6 during operation of the charging station 6. The radiation sensor 44 can be integrated directly into the charging station 6 or - as in 3 shown - be provided as an external component. In the latter case, the radiation sensor 44 is connected to the control electronics 26 of the charging station 6 via a wired (or alternatively wireless) data transmission connection 46 . In all cases, the radiation sensor 44 delivers a measurement signal M of the actual solar radiation to the control electronics 26.

In the execution of the device 2 according to 3 the electronic control system 26 determines the default value V--in a manner similar to that in the embodiment according to FIG 1 - 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: $$\text{M}\left(\text{t}\right)\cdot \text{L}\left(\text{t}\right)\to \text{V}$$

In this case, the charging curve L is preferably only defined over the duration of one day and is therefore followed in the same way every day. Furthermore, the charging curve L is expediently created here by the configuration app 36 in such a way that it only reproduces the efficiency curve of the PV system 14 resulting from the details b) to d) listed above for the PV system 14 .

The information about the solar radiation at the location of the charging station 14, and thus the information about the available solar power is in accordance with the version 3 obtained from the measurement signal M, through which the charging curve L is scaled as a function of the actual solar radiation.

In 4 the interaction of the measurement signal M and the charging curve L for generating the default value V is illustrated. From this representation it can be seen in particular that the default value V in the device 2 according to FIG 3 is not generated as a quasi-continuous variable, but jumps in a few discrete steps between a minimum V _min and a maximum V _max (this discretization of the default value V, which is mathematically equivalent to rounding the product M(t) L(t) is indicated by the use of an arrow instead of an equals sign in the above formula). In addition, the default value V is 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 device described in the two exemplary embodiments above can also be combined with one another in other ways within the scope of the claims.

Reference List

2

Furnishings

4

electric vehicle

6

charging station

8th

home power installation

10

network connection point

12

power grid

14

PV system

16

junction box

18

charging cable

20

charging plug

22

circuit breaker

24

main power line

26

control electronics

28

firmware

30

data line

32

data line

34

transceivers

36

configuration app

38

smart phone

40

data link

42

customization module

44

radiation sensor

46

data transfer connection

t

Time

ta

time (of sunrise)

do

time (of sunset)

IL

charging current

IN

mains power

IS

solar power

L

charging curve

Lmax

maximum value

min

minimum value

M

measurement signal

M0

threshold

V

default value

min

minimum

V max

maximum

Claims (17)

Method for operating a charging station (6) for charging an electric vehicle (4), wherein the charging station (6) can be connected directly or indirectly to a public power grid (12) via a local power distribution (8) in order to generate a charging current (I _L ). to provide a specific default value (V) of the charging current intensity for the electric vehicle (4), the default value (V) being specified to vary over time. procedure after claim 1 , the default value (V) of the charging current intensity being determined using a charging curve (L) stored in the charging station (6) or an external data memory, in particular in the form of a time-dependent mathematical function or support point table. procedure after claim 2 , The charging curve (L), in particular by means of input means of the charging station (6) or an external programming module, can be changed. procedure after claim 2 or 3 , wherein the charging curve (L) is specified in such a way that it is correlated with the average course of the solar radiation and/or wind speed, in particular specifically for the geographic location of the charging station (6). Procedure according to one of claims 2 until 4 , wherein the charging curve (L) is predetermined in such a way that it is correlated with the seasonally varying length of days at the geographic location of the charging station (6). Procedure according to one of Claims 1 until 5 , the default value (V) of the charging current depending on at least one piece of information about a photovoltaic system (14), in particular the rated power of the photovoltaic system (14), the inclination of the photovoltaic system (14), the geographical position of the photovoltaic system (14) and/or the geographical orientation of the photovoltaic system (14) with respect to the cardinal points, and/or depending on an indication of a wind power plant, in particular the nominal power of the wind power plant, is varied. Procedure according to one of Claims 1 until 6 , The default value (V) of the charging current depending on information about the actual solar radiation and / or depending on information about the actual wind speed at the geographic location of the charging station (6) is varied. procedure after claim 7 , wherein as information about the actual solar radiation or wind speed - measurement data of a radiation sensor (44) or wind sensor integrated into the charging station (6) or connected to the charging station (6). - the measured mains voltage, and/or - forecast data from a weather service are used. procedure after claim 8 , wherein the forecast data, in particular in the form of a long-term forecast covering several days, is determined using an app installed on a mobile terminal device, which can be connected to the control electronics (26) of the charging station (6) in terms of data transmission, and the forecast data or the data depending thereon adapted charging curve (L) are transmitted from the mobile device to the charging station (6) when the app is connected to the charging station (6). Device (2) for charging an electric vehicle (4), with a charging station (6) which can be connected directly or indirectly via a local power distribution (8) to a public power grid (12) in order to charge a charging current (I _L ) for the electric vehicle (4), the charging station (6) comprising control electronics (26) which is set up to enable a charging process for charging an electric vehicle (4) and to specify a default value (V) for the charging current intensity that varies over time . Device (2) after claim 10 , wherein the control electronics (26) are set up to determine the default value (V) of the charging current based on a charging curve (L) stored in the charging station (6) or an external data memory, in particular in the form of a time-dependent mathematical function or support point table. Device (2) after claim 11 , With input means of the charging station (6) and / or an external programming module, by means of which the charging curve (L) can be changed. Device (2) after claim 11 or 12 , where the charging curve (L) is specified in such a way that that it is correlated with the average course of the solar radiation and/or wind speed, in particular specific to the geographic location of the charging station (6). Device (2) according to one of Claims 11 until 13 , wherein the charging curve (L) is predetermined in such a way that it is correlated with the seasonally varying length of days at the geographic location of the charging station (6). Device (2) according to one of Claims 10 until 14 , with an adjustment module (42) that is set up to adjust the default value (V) as a function of at least one piece of information about a photovoltaic system (14), in particular the rated power of the photovoltaic system (14), the inclination of the photovoltaic system (14), the geographic To vary the position of the photovoltaic system (14) and/or the geographic orientation of the photovoltaic system (14) with respect to the cardinal points and/or depending on an indication of a wind turbine, in particular the nominal output of the wind turbine. Device (2) according to one of Claims 10 until 15 , The control electronics (26) or an external control device being set up to set the default value (V) of the charging current depending on information (M) about the actual solar radiation and/or depending on information about the actual wind speed at the geographic location of the charging station (6) to vary. Device (2) after Claim 16 , wherein the control electronics (26) or the external control device are set up to, as information about the actual solar radiation or wind speed - a measurement signal (M) of a radiation sensor (44) or wind sensor integrated into the charging station or connected to the charging station, - the measured mains voltage, and/or forecast data from a weather service.

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