DE102022119767A1 - Grid-friendly charging management for an electric vehicle - Google Patents

Abstract

A charging control (2) of an electric vehicle (2) and an associated method for charging the electric vehicle (2) are specified. The charging control (6) sets a default value (V) for the charging current or charging power of a charging current (IL) obtained from the electric vehicle (2) in a time-varying manner, so that the default value (V) is opposite to the network utilization of the power grid (14). varies.

Description

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

Electric vehicles usually obtain the charging current directly from a local power distribution (in particular by connecting the electric vehicle to a household socket or power socket) or from a charging station that can be connected to a public power grid either directly or indirectly via a local power distribution in order to provide the charging current for the To provide electric vehicles. In the latter case, the charging station releases the charging process (i.e. the output of the electrical charging current) through communication with a charging controller of the electric vehicle and usually specifies a default value for the current strength of the charging current. The default value defines the maximum 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 final control of the charging current is carried out by the electric vehicle and the DC charger provides the requested charging current to the vehicle.

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 power 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 charging station or the connected electric vehicle and therefore do not belong to the public power grid.

When the electric vehicle is directly connected to the local power distribution, the charging process starts 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 can often be set at the charging station or in the electric vehicle or by means of a software application (app) that works on the charging station or the electric vehicle.

The growing spread of e-vehicles and associated charging stations is becoming an increasing stress test for public power grids. In particular, it is foreseeable that with the existing network infrastructure, the expected future demand for charging current will not be able to be provided without supporting measures.

The invention is based on the object of providing a network-friendly charging management for charging an electric vehicle. The method should be particularly inexpensive to implement.

With regard to a method for charging an electric vehicle, this object is solved according to the invention by the features of claim 1. With regard to an electric vehicle, the above object is solved according to the invention by the features of claim 10. Advantageous and partly inventive embodiments of the invention are set out in the subclaims and the following description.

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 (von null verschiedenen) konstanten oder ebenfalls veränderlichen Parameter steht.According to the invention, it is provided that the default value of the charging current or charging power is specified in a time-varying manner by a charging control of the electric vehicle, so that the default value varies in the opposite direction to the network utilization of the power grid. The default value is varied in particular continuously or in several stages. The default value 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) depending on the time t, 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 L can directly reflect the default value V of the charging current 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 (non-zero) constant or also variable parameter.

Within the scope of the invention, the charging curve can be programmed by the manufacturer into the charging control of the electric vehicle or an external control device of the electric vehicle or made available on a storage medium (e.g. an SD card). Alternatively, the charging curve can be transferred to the charging controller or the external control device via download (e.g. via a mobile phone network, WiFi or via Bluetooth using a mobile device). The charging curve can still be made available either as a one-time fix or updated regularly or irregularly.

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 (i.e. one point per hour), 96 points (i.e. one point per quarter of an hour) or 1440 points (i.e. 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 (e.g. only between 7 a.m. and 10 p.m.). However, the charging curve is preferably also variable on a time scale exceeding 24 hours, in particular for a week, one or more months or - preferably - a whole year. Instead of a single connected charging curve, the charging curve can also be composed of several curve pieces (or files) that are used alternatively to each other. For example, a separate charging curve is stored for each month of the year.

The charging curve is preferably stored in the charging control of the electric vehicle itself. Alternatively, the charging curve can also be stored in an external data memory (i.e. not part of the charging control), e.g. a memory card or the memory of an external control device (e.g. an on-board computer of the electric vehicle or a cloud server) and from there be made available to the charging controller during operation to generate the default value.

Controlling the default value based on the stored charging curve has the advantage that network-friendly charging management is possible without complex installation, in particular without the use of external electricity meters or current sensors and their data transmission connection to a charging station. Because the default value for the charging current or charging power is specified by the charging control of the electric vehicle according to the invention, 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, within the scope of the invention it can also be provided that the charging control of the electric vehicle when connecting it to a public or private charging station gives the charging station a priority with regard to the specification of the default value (in particular when 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 its own default value when the electric vehicle is charged at a public AC charging station or a 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. This makes it possible, for example, to charge the electric vehicle with high charging current or charging power, decoupled from the load on the public power grid, if there is enough in the local power distribution to which the charging station is connected due to local power sources (e.g. a PV system or a battery storage system). electrical power is available.

In some embodiments of the invention, the charging control of the electric vehicle can be operated offline, i.e. without permanently connecting the charging station to a regional or supra-regional data transmission network such as the Internet and/or a mobile phone network. In particularly simple versions, the charging control therefore does not include any interfaces for connection to such data transmission networks.

The variation of the default value, which is opposite to the grid utilization of the power grid, means that the default value of the charging current or charging power is always reduced or even reduced to zero when the grid utilization of the power grid is particularly high, whereas the default value is increased in times of low grid utilization. This ensures that the electric vehicle does not contribute to increasing the fluctuations in network utilization that exist independently of e-mobility, but rather helps the operators of the affected public power grids (network operators) to better distribute the network utilization over time and thus at a comparatively lower level To provide a particularly large amount of charging current overall during peak grid utilization.

In a preferred embodiment of the invention, a network utilization curve A(t) is specified as the charging curve, which represents the network utilization of the power network in a time-resolved manner. The default value is determined based on the distance (ie the difference) of a current value of the network utilization curve to a given threshold value A _max , for example according to $$\text{v}=\text{k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}},$$

When loading, the default value V is expediently set within specified limit values [V _min ; V _max ] held. Here, the parameter V _min stands for the minimum charging current required by the charging control of the electric vehicle, if the value falls below this the default value is set to zero.

• - 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 bestimmt.In an advantageous embodiment, the charging curve (in particular in the form of the network utilization curve, also known as the "load profile") is defined specifically for the geographical location of the electric vehicle and can therefore - depending on the geographical dependency of the charging curve - also change when the electric vehicle is vehicle is moved. The geographical location 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 it is for

• - 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.

Alternatively, within the scope of the invention, the charging curve can also be calculated and specified specifically for a delimited network area of the power network to which the electric vehicle is connected, e.g. for a line harness, a distribution network area, a balancing group or a local or regional network operator. The delimited network area can include one or more network levels.

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

jeweils einen individuellen Tagesverlauf aufweist. Dem liegt die Erkenntnis zugrunde, dass die durchschnittliche Netzauslastung typischerweise einen Tagesverlauf mit drei Maxima (Peaks), nämlich einem Morgen-Peak, einem Mittags-Peak und einem Abend-Peak, aufweist. In den Wintermonaten sind hierbei typischerweise der Morgen-Peak und der Abend-Peak besonders ausgeprägt, da zu diesen Zeiten vermehrt elektrische Energie für Beleuchtung und zur Wärmeerzeugung verwendet wird. In den Sommer-Monaten ist dagegen der Mittags-Peak besonders ausgeprägt, da hier in der Tagesmitte vermehrt elektrische Energie zum Kühlen verbraucht wird. Zudem weist die durchschnittliche Netzauslastung auch starke Unterschiede zwischen Werktagen und arbeitsfreien Tagen auf. So tritt an arbeitsfreien Tagen (insbesondere im westeuropäischen Raum an Sonntagen) der Morgen-Peak deutlich später auf als an Werktagen und verschmilzt dabei unter Umständen (insbesondere in den Wintermonaten) mehr oder weniger mit dem Mittags-Peak. Diese Unterschiede der durchschnittlichen Netzauslastungskurve werden vorzugsweise in der Ladekurve berücksichtigt. Hierdurch wird der Vorgabewert während des Morgen-Peaks, des Mittags-Peaks und/oder des Abend-Peaks vorübergehend, gegebenenfalls bis auf null, reduziert.In a simple to implement but still effective embodiment of the invention, the charging curve is specified in such a way that it is adapted to the average differences in network utilization over the course of the week and/or year. Within the scope of the invention, the average difference in network utilization over the course of the year can be depicted in the charging curve with different temporal precision. For example, the charging curve within the scope of the invention can be specified in such a way that it

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

each has an individual daily course. This is based on the knowledge that the average network utilization typically has a daily course with three maxima (peaks), namely a morning peak, a midday peak and an evening peak. In the winter months, the morning peak and the evening peak are typically particularly pronounced, as at these times more electrical energy is used for lighting and to generate heat. In the summer months, however, the midday peak is particularly pronounced, as more electrical energy is used for cooling in the middle of the day. In addition, the average network utilization also shows strong differences between working days and non-working days. This occurs on non-working days (especially in Western Europe (e.g. on Sundays) the morning peak occurs significantly later than on weekdays and under certain circumstances (particularly in the winter months) merges more or less with the midday peak. These differences in the average network utilization curve are preferably taken into account in the charging curve. This temporarily reduces the default value during the morning peak, the midday peak and/or the evening peak, possibly down to zero.

• - die gemessene Netzspannung (insbesondere anhand von Messdaten eines in die Ladesteuerung integrierten Netzspannungssensors), und/oder
• - die gemessene Netzfrequenz, und/oder
• - Prognosedaten bezüglich einer zu erwartenden Netzauslastung

herangezogen.In a further advantageous embodiment of the invention, the default value is varied depending on information about the (current or forecast) actual network utilization at the geographical location of the electric vehicle or in the delimited network area. In particular, information about the actual network utilization is provided

• - the measured mains voltage (in particular based on measurement data from a mains voltage sensor integrated into the charging control), and/or
• - the measured network frequency, and/or
• - Forecast data regarding expected network utilization

used.

The optional use of the grid voltage and/or the grid frequency as a control variable for setting the default value is based on the knowledge that the grid voltage fluctuates slightly with the local and regional grid load. In particular, the default value 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 in the charging station is controlled depending on the data from electricity meters or current sensors, the variant of the invention described above has the advantage that the measurement of the mains voltage can (and preferably does) take place in the charging control of the electric vehicle itself ), so that a complex installation is not necessary (and especially not available).

Forecast data about network utilization is automatically retrieved from the Internet by the charging controller or an external control device in the electric vehicle.

In a particularly advantageous embodiment of the invention, the electric vehicle (and thus the charging controller) is directly connected to the Internet, for example via its own mobile phone connection. In this case, the electric vehicle downloads the forecast data on network utilization independently and automatically.

Alternatively, the forecast data is downloaded or determined using a software application (app) installed on a mobile device (e.g. smartphone or tablet), this app being connected to the charging control of the device using a transmitting and receiving unit of the device, for example via Bluetooth E-vehicle can be connected. This app (also known as the “operating app”) is preferably set up for configuration and/or remote control of the charging controller and is therefore designed to be regularly connected to the charging controller by a user of the electric vehicle. The app is set up to transfer the forecast data to the charging controller whenever the app is connected to the charging controller; in particular whenever the mobile device on which the app is installed is close to the electric vehicle, or when the user operates the charging control using this app. 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 app is reconnected to the charging controller, the long-term forecast stored in the charging controller 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 of the expected network utilization - the charging curve adjusted based on the forecast is transferred to the charging control when the mobile device is connected to the charging control.

An advantage of the last described embodiments is that the charging control itself can (and preferably will) be operated offline. The charging control is preferably not equipped with means for connecting to the Internet, which enables the charging control to be implemented simply and inexpensively. Another advantage of this embodiment is that the computing capacity of the mobile device for obtaining the forecast data and, if necessary, the calculation of the adjusted th charging curve can be used. This allows a correspondingly smaller dimensioning of the computing power of the charging control.

Within the scope of the invention, the information about the actual network utilization can be used in combination with a stored charging curve or independently of it. In the former case, for example, the predetermined charging curve is increased/decreased or scaled depending on the information about the actual network utilization. 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 network utilization.

In a further advantageous embodiment of the invention, the default value is determined based on a control signal from a network operator that is dependent on the network utilization. In the context of the invention, the control signal can be a (binary) switch-off signal, through which - especially in the event of an impending network overload - the default value of the charging current is set to zero and which thus causes an interruption of an ongoing charging process. Alternatively, the control signal can also be a differentiated signal, which, for example, causes the default value to be reduced to a predetermined percentage of the maximum charging current when the network is busy. Preferably, the control signal - if available - is taken into account in addition to the average network utilization and/or the actual network utilization when determining the default value. For example, the guide signal is always used to determine the default value - e.g. instead of the stored charging curve or instead of forecast values of the expected network utilization - when the guide signal is fed to the charging control of the electric vehicle. A control signal that may be present is therefore given priority. However, whenever the guide signal is not present (e.g. because the transmission of the guide signal is disrupted or the network operator does not provide such a guide signal), other means are used to determine the default value, e.g. a stored charging curve or forecast values of the expected ones Network utilization. Alternatively, in expedient embodiments of the invention, the control signal is combined with the stored charging curve or the forecast values of the expected network utilization in such a way that the default value resulting from the charging curve or the forecast values is scaled or shifted depending on the control signal.

The charging control of conventional electric vehicles often does not allow for a continuous variation of the charging current, but instead changes the charging current in discrete steps. In particular, the charging control usually requires a minimum charging current of, for example, 6A. If the available charging current falls below this minimum charging current (also known as the switch-off threshold), the charging process is completely interrupted by the charging control. It has been recognized that this switch-off threshold - particularly when using the method according to the invention - could lead to shock-like load changes in the power network, which under certain circumstances could endanger network stability. Such a case could occur, for example, if in a regional subnetwork a large number of electric vehicles operating according to the method according to the invention switch off at the same time due to an increasing network load due to a stored charging curve, due to the information about the actual network utilization or due to the control signal from the energy supplier, so that abruptly a multiple of the minimum charging current is released.

In order to avoid such shock-like load changes that are dangerous for network stability, a change in the default value, in particular a reduction of the default value to zero, caused by the charging curve, the information about the actual network utilization or the energy supplier's control signal, is preferably not carried out immediately in the course of the method, but with a time delay compared to the triggering event. In the case of unforeseeable events (e.g. an increase in the actual network load or a change in the control signal), the default value is always changed with a time delay after the event (in particular set to zero). In the case of a permanently stored charging curve, the default value can alternatively be changed proactively (i.e. with a negative time offset before the triggering event), in particular set to zero. The time offset is varied in a way that is specific to the electric vehicle or the current charging cycle. For example, the time offset is varied depending on a duration of an ongoing charging cycle, a charging status of a charged vehicle battery, an amount of energy charged during the ongoing charging cycle, or a random number.

The time offset can optionally be chosen to be the same or different for negative changes in the default value (in particular shutdown processes) and positive changes in the default value (in particular restart processes). The time offset when switching off (i.e. reducing the default value to zero) is preferably chosen to be shorter than when switching on again (i.e. increasing the default value from zero to a positive value). For example, the time offset for switching off becomes like this determines that the charging control switches off 15 seconds before a predetermined switch-off time for each minute of the previous charging time in the current charging cycle. If the electric vehicle had already been charged for 30 minutes before the intended switch-off time, the charging process will, for example, be interrupted by a time delay of 7.5 minutes (namely 30 x 15 seconds) before the switch-off time. For reconnection, for example, a double time offset of 30 seconds per minute of charging time after a reconnection time is provided, so that if the charging time preceding the interruption was 30 minutes, the charging process is resumed by a time offset of 15 minutes after the reconnection time.

In addition or as an alternative to the time-delayed interruption and resumption of the charging process, it is optionally provided that the rate of change (i.e. the temporal edge steepness of a change) of the default value is limited. For example, the rate of change of the default value is limited to one amp per minute. This limitation of the rate of change of the default value also dampens rapid (shock-like) load changes in network utilization, which can otherwise lead to network instability. Within the scope of the invention, the limitation of the rate of change of the default value can be provided in the entire value range of the default value or - preferably - only for small default values in the vicinity of the switch-off threshold or at high network utilization. Furthermore, the limit value for negative rates of change of the default value (i.e. for a reduction in the default value) can be chosen to be the same as or different from the limit value for positive rates of change of the default value (i.e. for an increase in the default value). For example, the decrease in the default value before switching off is limited to 1 ampere per minute and the increase in the default value after reconnection is limited to 0.5 amperes per minute.

What all of the variants described above have in common is that the time offset is usually different for different electric vehicles, even with the same configuration and the same network load, so that the electric vehicles change the default value, in particular switch off, at different times even under the same network conditions.

In a particularly preferred embodiment, the charging control additionally comprises a software application (operating app), which is intended and set up for configuration and/or remote control of the charging control, and which can be installed on a smartphone or computer (e.g. a notebook or tablet). The smartphone or the computer on which the operating app is installed or can be installed is generally not part of the invention (in particular the charging controller according to the invention) and is regularly manufactured and sold independently of the charging controller. Rather, the smartphone or computer is only used by the operating app 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 control as a resource for electrical power, without becoming a component of the charging control become). The operating app can be connected to the vehicle-internal part of the charging control, preferably via a wireless data transmission link (in particular via Bluetooth or mobile communications). For this purpose, the operating app uses a corresponding transmitting and receiving unit on the smartphone or computer.

Preferably, a reduction of the default value caused by the charging control due to the network utilization, in particular a reduction of the default value to zero, can be overwritten by a user command (“override command”), so that the user can charge the electric vehicle with a higher charging current or higher charging power, especially with maximum charging current, can be enforced. However, the override command may be tied to a special fee or a special electricity tariff by the network operator. In an expedient embodiment of the invention, the charging control is set up against this background to report the override command to a network operator or an electricity meter of the local electricity distribution in order to trigger the special charge or the special electricity tariff.

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. Explanations of variants of the method and their respective effects and advantages must be transferred accordingly to the charging control and vice versa.

Specifically, the charging control includes in particular an electrical charging circuit, which supplies the charging current with controllable charging current or charging power from a charging interface of the e-drive equipment (namely usually a charging plug) to the vehicle battery of the electric vehicle, as well as control logic for controlling the charging current strength or charging power of the charging current. The control logic is set up to enable a charging process for charging an electric vehicle and to specify a default value that varies over time, in particular continuously or in several stages, so that the default value varies in the opposite direction to a network utilization of the power grid. The control logic is preferably set up to determine the default value of the charging current based on a charging curve stored in the charging controller or an external data memory, in particular in the form of a time-dependent mathematical function or reference point table.

The control logic is preferably integrated together with the charging circuit in a common component. In this case, the control logic is preferably implemented as a programmable component, e.g. 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 another alternative embodiment, the control logic is designed as a pure software product that is installed and ready to run in a separate control unit in the electric vehicle, e.g. an on-board computer. In yet another alternative embodiment, part of the control logic is integrated together with the electrical charging circuit in a structural unit, while another part of the control logic is installed in a separate control device, e.g. the on-board computer.

In an advantageous embodiment of the charging control, a network utilization curve is specified as the charging curve, which specifically reflects the average network utilization at the geographical location of the e-vehicle or in the delimited network area in which the e-vehicle is connected. The charging control is set up to determine the default value based on the distance between a current value of the network utilization curve and a predetermined threshold value. Alternatively, within the scope of the invention, the charging curve can also be specified in such a way that it varies in the opposite direction to the average network utilization at the geographical location or the delimited network area.

The charging electronics are preferably set up to vary the default value depending on information about the (current or forecast) actual network utilization at the geographical location of the e-vehicle or in the delimited network area in which the e-vehicle is connected. If a high network utilization is determined, the default value in particular is adjusted to lower values than when the network utilization is low.

In an advantageous embodiment, the charging controller is set up to use measurement data from a network voltage sensor or network frequency sensor integrated into the charging controller or connected to the charging controller and/or forecast data regarding an expected network load as information about the actual network utilization. The sensors mentioned above can be a separate component of the charging control according to the invention. Alternatively, within the scope of the invention, the charging control can also access data from external sensors, e.g. sensors of a smart home system of the local power distribution to which the electric vehicle is connected, etc.

Additionally or alternatively, the charging control is set up to receive (wirelessly or wired) a control signal from a network operator that depends on the network utilization. The charging control is set up to determine the default value (if necessary) based on the control signal.

In an advantageous embodiment, the charging control is set up to carry out a change in the default value, in particular a reduction of the default value to zero, with a time offset caused by the charging curve, the information about the actual network utilization or the control signal from the energy supplier, and the time offset in a for to vary the electric vehicle or the current charging cycle in a specific way. In particular, the time offset is varied by the charging control depending on a duration of an ongoing charging cycle, a charging status of a charged vehicle battery, an amount of energy charged during the ongoing charging cycle, or a random number.

Optionally, the charging control or any external control device in the electric vehicle is equipped with communication electronics, for example a mobile phone, LAN and/or WLAN adapter, for wired or wireless data exchange with a remote server, in particular on the Internet, e.g independently retrieve forecast data regarding the expected network load.

The charging control optionally further includes a receiver for signals from a global positioning system (e.g. a GPS receiver) or accesses such a receiver of the electric vehicle. The charging control is set up to automatically determine the geographical location of the electric vehicle. Alternatively, the charging control is set up to automatically determine the geographical location of the e-vehicle by means of the named receiver by communicating with a data transmission network (e.g. a mobile phone or WLAN network). Alternatively, within the scope of the invention, the geographical location of the electric vehicle is also stored manually (e.g. using the operating app described above) in the charging control or automatically determined by the operating app, if any, and transmitted to the charging control or when creating the Charging curve taken into account. In particularly simple versions, the charging control is intended exclusively for offline operation. In these embodiments, the charging control preferably does not include any interfaces for communication with a WLAN or cellular network.

The charging control 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.

Optionally, the charging control is also set up to recover electrical energy from the vehicle battery into the charging station or the local power distribution, from where the recovered energy is in turn optionally returned in whole or in part to the power grid. As part of the method and the associated charging control, the default value of the charging current or charging power can be specified in particular in such a way that it can also assume one or more negative values. In the case of a negative default value, instead of a charging current supplied to the vehicle battery, a feedback current (a maximum corresponding to the default value) is retrieved from the vehicle battery. In embodiments of the invention in which the default value is determined by a load curve, this network utilization curve is in particular specified in such a way that the default value temporarily becomes negative during times of particularly high network utilization. Alternatively, such a sign reversal of the default value can also be caused within the scope of the invention by the information about the actual network utilization or the control signal from the energy supplier.

In an advantageous embodiment of the invention, the charging control further controls the charging process depending on an expected energy requirement of the electric vehicle, in particular depending on the expected start and the expected duration or distance of at least one next trip of the electric vehicle. The expected energy requirement is determined - e.g. by the charging control, the on-board computer of the e-vehicle or an external computer - based on typical usage behavior and/or based on user input. For example, the charging control reduces the default value of the charging current or charging power if it emerges from the typical usage behavior and/or the user input that, even with the reduced charging current or charging power, there is sufficient battery charge for this expected trip by the start of the next expected trip is achieved. In a specific application example of this charging strategy, the electricity or power requirement required to achieve the desired state of charge of the battery is distributed over the expected charging time (e.g. the user's expected working time) in such a way that charging is carried out in a particularly network-friendly manner. For example, the charging process is stretched over a period of 5 hours with an average charging power of 4 kW, taking the network load into account, instead of charging the electric vehicle within one hour with a charging power of 22 kW. Additionally or alternatively, the charging control only partially charges the battery and ends the charging process before full charge is reached if the typical usage behavior and/or the user input indicates that the state of charge reached is for the next expected trip or several trips in close succession expected journeys is sufficient. This partial charging of the battery is carried out in particular before working days if the typical usage behavior and/or user input shows that the electric vehicle is typically only driven over a short distance on working days (e.g. between the vehicle user's place of residence and the place of work). The vehicle user can preferably override the reduction of the charging current or charging power or the termination of the charging process in the case of partial charging due to the typical usage behavior through a user input, e.g. by specifying the start and duration or route of a planned trip. The vehicle user can therefore in particular force an increased charging current or charging power if an atypically early start to the journey is planned. Additionally or alternatively, the vehicle user can force the battery to have an increased state of charge (or full charge if necessary) if an atypically long or far journey is planned.

A further embodiment of the invention is an electric vehicle which includes the charging control according to the invention described above and which therefore operates according to the method according to the invention.

• 1 in einem schematischen Blockschaltbild ein Elektro-Fahrzeug (E-Fahrzeug), das zum Bezug eines Ladestroms über eine lokale Stromverteilung (hier beispielhaft eine elektrische Haustrominstallation) an ein öffentliches Stromnetz anschließbar ist, wobei eine Ladesteuerung des Kraftfahrzeugs einen Vorgabewert der Ladestromstärke anhand einer hinterlegten, zeitabhängigen Netzauslastungskurve bestimmt, so dass der Vorgabewert gegenläufig zu dem durchschnittlichen Verlauf der Netzauslastung des Stromnetzes an dem geographischen Standort des E-Fahrzeugs variiert,
• 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 einem schematischen Diagramm gegen die Zeit drei typische Tagesverläufe der Netzauslastung im Winter, nämlich einen Tagesverlauf der Netzauslastung für einen Werktag (durchgezogene Linie), einen Tagesverlauf der Netzauslastung für einen Samstag (gestrichelte Linie) und einen Tagesverlauf der Netzauslastung für einen Sonntag (strichpunktierte Linie),
• 4 in zwei übereinander angeordneten, chronologischen Diagrammen den Tagesverlauf der Netzauslastung für einen Werktag aus 3 sowie einen oberen Schwellwert und einen unteren Schwellwert für die Netzauslastung (oberes Diagramm) und den Verlauf des aus dem Abstand der Netzauslastung zu dem oberen Schwellwert abgeleiteten Vorgabewerts der Ladestromstärke (unteres Diagramm),
• 5 in Darstellung gemäß 4 wiederum den Tagesverlauf der Netzauslastung für einen Werktag aus 3 (oberes Diagramm) sowie den Verlauf des Vorgabewerts der Ladestromstärke (unteres Diagramm), wobei der Vorgabewert nach einem alternativen Verfahren aus dem Abstand der Netzauslastung zu dem oberen Schwellwert abgeleitet ist, und
• 6 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.

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), which can be connected to a public power grid to obtain a charging current via a local power distribution (here, for example, an electrical house power installation), wherein a charging control of the motor vehicle determines a default value of the charging current based on a stored, time-dependent network utilization curve is determined, so that the default value varies in the opposite direction to the average course of the network utilization of the electricity network at the geographical location of the e-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 a schematic diagram against time, three typical daily patterns of network utilization in winter, namely a daily pattern of network utilization for a working day (solid line), a daily pattern of network utilization for a Saturday (dashed line) and a daily pattern of network utilization for a Sunday (dash-dotted line). ),
• 4 shows the daily course of network utilization for a working day in two chronological diagrams arranged one above the other 3 as well as an upper threshold value and a lower threshold value for the network utilization (upper diagram) and the course of the default value of the charging current derived from the distance between the network utilization and the upper threshold value (lower diagram),
• 5 in representation according to 4 in turn shows the daily course of network utilization for a working day 3 (upper diagram) and the course of the default value of the charging current (lower diagram), whereby the default value is derived using an alternative method from the distance between the network utilization and the upper threshold value, and
• 6 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).

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. When the electric vehicle 2 is in operation, the battery 4 feeds an electric drive motor (not shown) of the electric vehicle 2. The charging controller 6 is used to control a charging process, in which the charging controller 6 of the battery 4 supplies an electrical charging current I _L with an adjustable charging current intensity or .Provides 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 domestic 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 alternating current into a direct current with adjustable voltage or current to be supplied to the battery 4. 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) to the on-board computer 8. In addition, the charging control 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 be described in more detail below Way to exchange data with the Internet. 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.

The charging plug 20 of the electric vehicle 2 is designed, for example, as a “Type 2 plug” (ie a plug according to IEC 62196 Type 2), to which the charging cable 22 of the electric vehicle 2 can be connected with a corresponding charging socket. In the in 1 illustrated example, in which the charging cable 22 for charging the electric vehicle 2 is plugged into the socket 24 with its end remote from the vehicle, the charging cable 22 is provided with a suitable plug at this end.

During a charging process, the charging controller 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.

The control logic 28 of the charging controller 6 initiates a charging process either at the request of a user or automatically when it detects the connection of the charging plug 20 to a suitable power source, for example the household 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 to 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 preferably has the value zero.

The control logic 28 determines the default value V based on a charging curve stored in a data memory of the control logic 28 depending on the time t and the geographical location.

In the in 1 to 3 In the example shown, the charging curve is predetermined in the opposite direction to the desired course of the default value V, so that it reflects the course of the average network utilization of the power grid 14 at the geographical location of the electric vehicle 2, for example as a percentage value relative to the maximum utilization of the power grid 14. The charging curve defined in this way is also referred to below as the network utilization curve A (A = A(t)). In 3 three exemplary sections of the network utilization curve A are shown versus time t, each of which corresponds approximately to a typical daily course of network utilization in a geographical area with residential development; The times t ₁ and t ₂ marked with dashed vertical lines correspond, for example, to 4:00 a.m. and 9:00 p.m. With a solid line is in 2 the average daily course of network utilization on a working day (Monday to Friday) is shown. In comparison, the average daily course of network utilization on a Saturday is shown with a dashed line. Finally, the average daily course of network utilization on a Sunday is shown with a dash-dotted line.

According to the representation 3 It can be seen that the average network utilization on working days has a daily course with three distinct maxima (peaks), namely a morning peak, a midday peak and an evening peak. On weekends, the morning peak typically occurs later and, in particular, merges more or less strongly with the midday peak. In addition, there are typically higher peaks in network utilization on weekends compared to weekdays.

3 shows the typical course of network utilization in winter. In the summer months, the midday peak is typically more pronounced, as more electrical energy is used for cooling in the middle of the day. In contrast, the morning peak and the evening peak are typically weaker in the summer months because less electrical energy is used for lighting and heat. Network utilization in industrial areas behaves differently again, with characteristic differences occurring over the course of the week and year.

These differences in the average network utilization over the course of the week and year are taken into account when determining the default value V in that the network utilization curve A is preferably defined over the entire (calendar) year. For example, the network utilization curve A is implemented in the form of 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 specified time resolution (e.g. at intervals of 5 minutes). The control logic 28 has, for example, a real-time clock and successively reads out value by value from the support point table based on the time t output by this clock (e.g. every 5 minutes).

$$\begin{array}{cc}\text{V}={\text{V}}_{\text{max}}& \text{für k}\cdot \left({\text{A}}_{\text{max}}-\text{A}\left(\text{t}\right)\right)+{\text{V}}_{\text{min}}>{\text{V}}_{\text{max}}\end{array}$$

$$\text{V}=0$$

sonstThe control logic 28 determines the default value by subtracting the current value A(t) of the stored network utilization curve A from a predetermined threshold value A _max and - preferably - multiplying the difference by a predetermined proportionality factor k: $$\begin{array}{cc}\text{v}=\text{k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}& {\text{for V}}_{\text{Max}}\ge \text{k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}\ge {\text{v}}_{\text{min}}\end{array}$$

$$\begin{array}{cc}\text{v}={\text{v}}_{\text{Max}}& \text{for k}\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}>{\text{v}}_{\text{Max}}\end{array}$$

$$\text{v}=0$$

otherwise

From the above equations it can be seen that the default value V is reduced to zero when the current value A(t) of the stored network utilization curve A exceeds the threshold value A _max . On the other hand, the default value V is limited to the maximum value V _max when the network load is low.

This procedure for determining the default value V is shown in the two diagrams 4 illustrated. The upper diagram shows the daily course of the network utilization curve A for a working day 3 shown. Additionally, in the diagram above are the 4 the threshold value A _max and another threshold value A _min are entered. The difference between the current value A(t) of the network utilization curve A and the threshold value A _max is illustrated by an arrow 38. The second threshold value A _min limits a control range of network utilization in which a restriction of the charging current I _L by the charging controller 6 makes sense. As long as this second threshold value A _min is undershot, the default value is set by the charging controller 6 to the maximum value V _max .

This is from the diagram below 4 can be seen in which the course of the default value V determined according to the principle described above is plotted against time t.

In the comparison of the two diagrams 4 It can be seen that at a time t ₃ , for example at approximately 7:00 a.m., the current value A(t) of the network utilization curve A exceeds the second threshold value A _min for the first time during the day, whereupon the control logic 28 counteracts the default value V reduced to the further course of network utilization.

During a time period limited by two times t ₄ and t ₅ between the midday peak and the evening peak, for example between 3:00 p.m. and 4:30 p.m., the average network load in the example shown temporarily falls below the second threshold value A _min , so that the default value V is set back to the maximum value V _max in this time interval. During the evening peak, between times t ₆ and t ₇ (e.g. between 5:45 p.m. and 7:45 p.m.), the network utilization exceeds the upper threshold value A _max . Accordingly, the control logic 28 sets the default value V in this period of time to zero and thus interrupts any charging process that may be in progress. At a time t ₈ (e.g. at approximately 10:15 p.m.) the average network utilization falls again below the second threshold value A _min , so that the default value is set again to the maximum value V _max .

The network utilization curve A is also stored as a function of the geographical location of the e-vehicle 2, so that the network utilization curve A has an individually adapted time course for different locations of the e-vehicle. The charging controller 6 receives the information about the geographical location of the e-vehicle 2 in particular from a GPS sensor integrated into the on-board computer 8.

In an alternative embodiment of the charging control 6, the network utilization curve A is not spatially resolved and is preferably only stored in the control logic 28 for a limited time interval of, for example, 48 hours. In order to still be able to provide a time- and location-specific charging curve, the control logic 28 in this embodiment is designed to connect to the Internet via the mobile radio transceiver 32 of the electric vehicle 2 at the start of each charging process and to communicate with one download a network utilization curve A from the corresponding web server, which reflects the average network utilization specifically for the current geographical location of the e-vehicle 2 and the current time.

In a further embodiment variant, the control logic 28 receives via the mobile radio network and the transceiver 32 a control signal from the network operator that is dependent on the actual network utilization, which sets a guideline value for the default value V and which is taken into account by the control logic 28 as an alternative or in addition to the stored network utilization curve A. For example, the control logic 28 is set up to determine the default value V based on the control signal whenever it is available, and alternatively to determine the default value V based on the stored network utilization curve A. This design of the control logic 28 makes it possible to operate the same charging controller 6 in a network-friendly manner both online (with a connection to the network operator's control center) and offline (without a connection to the network operator's control center).

In another, based on 5 illustrated variant of the charging control 6, the control logic 28 basically determines the default value V in the manner described above and in 4 illustrated way. However, the control logic 28 does not immediately switch the default value V from the minimum value V _min if the current value A(t) of the network utilization curve A exceeds the upper threshold value A _max or if the control signal that may be received requires the default value V to be reduced to zero to zero. Rather, the control logic 28 leaves the default value V in this case (in the example shown at time t ₆ ) initially at the minimum value V _min for a predetermined time offset, and only switches the default value V to zero after the time offset has expired, if then the current one Value A(t) of the network utilization curve A still exceeds the upper threshold A _max . The time offset is selected differently for each electric vehicle 2, and preferably also for each shutdown process. For example, the time offset is varied depending on the duration of an ongoing charging cycle, on the charging status of the battery 4 or on an amount of energy charged during the ongoing charging cycle. In particular, the time offset is chosen to be shorter, the longer the electric vehicle 2 has been charged (i.e. draws a charging current I _L that is different from zero), the more the battery 4 has already been charged or the more electrical energy has already been charged in the current charging cycle became. In an alternative embodiment of the invention, the time offset is determined based on a random number, this random number being determined either once and specifically for each electric vehicle 2 or with each switch-off process. All the measures described above achieve the effect that several electric vehicles 2 operating according to the method according to the invention generally do not reduce the default value V to zero at the same time, even under the same network conditions. This means that shock-like changes in the network load due to the simultaneous switching off of the charging current I _L in a large number of electric vehicles 2 are avoided.

In a further embodiment, the rate of change of the default value V is limited to predetermined limit values, for example to a maximum of 1 ampere per minute for reducing the default value V and a maximum of 0.5 amperes per minute for increasing the default value V. This leads to the in 4 and 5 The course of the network utilization curve A shown means that in the area of times t ₆ and t ₇ (i.e. before switching off and after switching back on) the default value V is only reduced or increased with a limited edge steepness.

In a further variant of the charging control 6, instead of an unchanging network utilization curve A (for a given location and a given time), a long-term forecast of the expected network is used utilization is stored as network utilization curve A in the control logic 28. The long-term forecast differs from the average network utilization in that foreseeable deviations from the average network utilization values, for example due to foreseeable weather events, are taken into account in the network utilization curve A. As a rule, the closer the forecast point in time is to the present, the more the long-term forecast deviates from the average network utilization and reflects the actual network utilization more accurately. For points in the more distant future, however, the long-term forecast changes to the average network utilization.

The network utilization curve A, calculated based on the long-term forecast, is updated by the network operator or service provider at short intervals (e.g. every two hours). The updated network utilization curve A is downloaded from the control logic 28, for example at regular intervals or at the beginning of each charging process, via the Internet and stored in the memory of the control logic 28.

In a further variant of the invention, the control logic 28 continuously measures the magnitude of the network voltage U as a measure of the actual network utilization. It compares the actual network utilization with the average network utilization (i.e. the current value of the stored network utilization curve A) and corrects the default value V if there is a significant deviation. For example, the proportionality factor k in the above equation is defined as a function of the measured grid voltage U and the grid utilization curve A: $$\text{v}=\text{k}\left(\text{A}\left(\text{t}\right),\text{U}\right)\cdot \left({\text{A}}_{\text{Max}}-\text{A}\left(\text{t}\right)\right)+{\text{v}}_{\text{min}}$$

In an alternative charging situation this is the case 6 the charging controller 6 is connected via the charging cable 22 to a charging station 40 (in particular a wallbox) connected to the house power installation 10. In this case, the charging cable 22 is preferably provided at the end remote from the vehicle with a “Type 2 plug” (ie a plug according to IEC 62196 Type 2), which can be connected to a corresponding socket of the charging station 40. Alternatively, the charging cable 22 is firmly attached to the charging station 40.

A difference to the charging situation according to 1 is that charging stations usually intervene in the charging process in a self-controlling manner by enabling or disabling the charging current I _L from the charging controller 6 of the electric vehicle 2 and specifying their own (vehicle-external) default value V` to limit the charging current I <sub>L</sub> . This default value V` is usually transmitted via a data line of the charging cable 22 from the charging station 40 to the charging controller 6 of the electric vehicle, which accordingly limits the current intensity of the charging current I _L to the default value V`.

In the case of simple charging stations 40, the default value V` is output as a variable that is constant over time and only specifies the maximum charging current for which the charging station 40 or the house power installation 10 connected to it are designed. More complex ("intelligent") charging stations 40 sometimes include load management, which reduces the current strength of the charging current I <sub>L</sub> drawn at this charging station 40 as necessary in order to avoid overloading the local power distribution. Such charging stations 40, which are used in particular in local power distributions with several charging stations 40, therefore output a time-dependent default value V` to the charging controller 6 of the electric vehicle 2. It would also be conceivable that future charging stations 40 also take into account the network utilization of the public power grid 14 when limiting the charging current I _L as part of load management.

In a simple to implement but practical embodiment of the charging control 6, the control logic 28 is designed to comparatively evaluate its own (vehicle-internal) default value V and the (vehicle-external) default value V` transmitted by the charging station 40 and to determine the current strength of the Charging current I <sub>L</sub> should always be limited to the smaller of the two default values V and V`. The control logic 28 therefore always limits the current strength of the charging current IL to the vehicle-internal default value V if this falls below the vehicle-external default value V`; and it always limits the current strength of the charging current I <sub>L</sub> to the vehicle-external default value V` if this falls below the vehicle-internal default value V.

1. a) ob der Vorgabewert V` durch die Ladestation 40 aufgrund eines Lastmanagements ermittelt wurde,
2. b) ob bei der Ermittlung des Vorgabewerts V` durch die Ladestation 40 die Netzauslastung des öffentlichen Stromnetzes 14, an das die Ladestation 40 angeschlossen ist, berücksichtigt wurde, und/oder
3. c) ob die lokale Stromverteilung 10, an die die Ladestation 40 angeschlossen ist, von der Netzauslastung des öffentlichen Stromnetzes 14 unabhängig ist (z.B., weil die lokale Stromverteilung nicht mit dem öffentlichen Stromnetzes 14 verbunden ist, oder den Ladevorgang aus einer eigenen Stromquellen wie z.B. einer lokalen PV-Anlage oder einem Batteriespeicher speist).

In an even more complex embodiment, the charging station 40, in addition to the default value V`, outputs additional information to the charging controller 6 of the electric vehicle 2, which indicates the type of charging station 40, the basis for the calculation of the vehicle-external default value V` and/or characterizes the structure of the local power distribution to which the charging station 40 is connected. For example, the additional information contains information from which the charging controller 6 can recognize

1. a) whether the default value V` was determined by the charging station 40 based on load management,
2. b) whether the network utilization of the public power grid 14 to which the charging station 40 is connected was taken into account when determining the default value V` by the charging station 40, and/or
3. c) whether the local power distribution 10, to which the charging station 40 is connected, is independent of the network utilization of the public power grid 14 (e.g. because the local power distribution is not connected to the public power grid 14, or the charging process from its own power sources such as a local PV system or a battery storage system).

Based on the additional information, the charging controller 6 in this embodiment decides whether it gives priority to the vehicle-internal default value V if it falls below the vehicle-external default value V`, or whether it always gives priority to the vehicle-external default value V`. The charging control 6 is in particular set up in such a way that it decides on the latter (and thus grants the default value V` a general priority and optionally sets the generation of the vehicle-internal default value V) if and as long as the additional information transmitted by the charging station 40 is one of the cases b) and c) described above.

The additional information is transmitted from the charging station 40 to the control logic 28, preferably via a separate data line of the charging cable 22. Alternatively, the additional information is transmitted from the charging station 40 to the charging controller 6 wirelessly, for example by means of Bluetooth, or by means of a powerline transmission, ie via a charging current line of the charging cable 22 by modulating the additional information to the charging current I _L .

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 method and 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

Onboard computer

10

House electricity installation

12

Network connection point

14

power grid

16

PV system

18

Charging current line

20

Charging plug

22

Charging cable

24

Power outlet

26

rectifier

28

Control logic

30

Tax software

32

Cellular transceiver

34

Current sensor

38

Arrow

40

Charging station

t

Time

t1-t8

time

IL

charging current

A

Network utilization curve

Amax

Threshold

Amine

Threshold

U

Mains voltage

UB

Battery voltage

v

Default value

V`

Default value

Vmax

Maximum value

Vmin

Minimum value

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). , so that the default value (V) varies in the opposite direction to the network utilization of the power network (14). Procedure according to Claim 1 , whereby the default value (V) is determined based on a charging curve stored in the charging controller (6) or an external data memory, in particular in the form of a time-dependent mathematical function or reference point table. Procedure according to Claim 2 , wherein a network utilization curve (A) which specifically reflects the network utilization at the geographical location of the electric vehicle (2) or in a delimited network area of the power network (14) to which the electric vehicle (2) is connected is specified as the charging curve, and where the default value (V) is determined based on the distance of a current value of the network utilization curve (A) to a predetermined threshold value (A _max ). Procedure according to Claim 2 or 3 , whereby the charging curve is adapted to average differences in network utilization over the course of the week and/or year. Procedure according to one of the Claims 1 until 4 , whereby the default value (V) is varied depending on information about the actual network utilization. Procedure according to Claim 5 , whereby - the measured network voltage (U), and/or - the measured network frequency, and/or - forecast data regarding an expected network utilization are used as information about the actual network utilization. Procedure one of the Claims 1 until 6 , whereby the default value (V) is determined based on a control signal from a network operator that depends on the network utilization. Procedure according to one of the Claims 1 until 7 , according to which a change in the default value (V), in particular a reduction of the default value (V) to zero, caused by the charging curve, by the information about the actual network utilization or by the network operator's control signal, is carried out with a time offset, and the time offset in is varied in a manner specific to the electric vehicle (2) or the current charging cycle. Charging control (6) for an electric vehicle (2), which can be connected to a public power grid (14) via a local power distribution (8) or a charging station (40) in order to obtain a charging current ( _IL ) for the electric vehicle (2). , wherein the charging control (6) is set up to enable a charging process for charging an electric vehicle (2) and to specify a default value (V) of the charging current or charging power in a time-varying manner, so that the default value (V) is opposite to a network utilization of the Power grid (14) varies. Charging control (6). Claim 9 , which is set up to determine the default value (V) based on a charging curve stored in the charging controller (6) or an external data memory, in particular in the form of a time-dependent mathematical function or base point table. Charging control (6). Claim 10 , whereby a network utilization curve (A) which specifically reflects the network utilization at the geographical location of the electric vehicle (2) or in a delimited network area of the power network (14) to which the electric vehicle (2) is connected is specified as the charging curve, and the charging control ( 6) is set up to determine the default value (V) based on the distance of a current value of the network utilization curve (A) to a predetermined threshold value (A _max ). Charging control (6). Claim 10 or 11 , whereby the charging curve is adapted to average differences in network utilization over the course of the week and/or year. Charging control (6) according to one of the Claims 9 until 12 , which is set up to vary the default value (V) depending on information about the actual network utilization. Charging control (6). Claim 13 , which is designed to use - the measured network voltage (U), and / or - the measured network frequency, and / or - forecast data from a network operator regarding an expected network utilization as information about the actual network utilization. Charging control (6) one of the Claims 9 until 14 , which is set up to receive a control signal from a network operator that depends on the network utilization, and wherein the charging control (6) is set up to determine the default value (V) based on the control signal. Charging control (6) according to one of the Claims 9 until 15 , which is set up to carry out a change in the default value (V), in particular a reduction of the default value (V) to zero, with a time offset caused by the charging curve, the information about the actual network utilization or the network operator's control signal, and the time offset in to vary in a way specific to the electric vehicle (2) or the current charging cycle. Electric vehicle (2) with a charging control (6) according to one of the Claims 9 until 16 .

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