Method for charging a plurality of electrically driven motor vehicles via a common charging station

Abstract

The invention relates to a method for charging a plurality of electrically driven motor vehicles (1) via a common charging station (2), in which charging station the charging current of the charging station (2) is fed on the input side to a charging distributor (4) and is fed on the output side by the charging distributor (4) to the motor vehicles (1) to be charged via connections (5), wherein, once the connection (5) is connected (6), the battery status for each connected motor vehicle (1) is determined (7). In order to design a method of the type mentioned at the outset such that reliable series charging of a plurality of electric vehicles by only one charging station is made possible using means which are as technically simple as possible, and in which, at the same time, the completion time of the charging process of each vehicle can be reasonably estimated or determined, according to the invention the connected motor vehicles (1) can subsequently be placed in a sequence (8) and, starting with the first motor vehicle (1) in the sequence as the selected motor vehicle (1) in a series charging process, the charging distributor (4) allows (9), by means of a transmitted release signal for tapping charging current exclusively for the selected motor vehicle (1), said vehicle (1) to tap the charging current until the battery status of this motor vehicle (1) corresponds to a target value stored in the charging distributor, and upon reaching this target value the series charging process is carried out for the next motor vehicle (1) in the sequence as the selected motor vehicle (1).

Description

[0001] Method for charging several electrically powered motor vehicles via a common charging station

[0002] Technical area

[0003] The invention relates to a method for charging several electrically powered motor vehicles via a common charging station, in which the charging current of the charging station is supplied to a charging distributor on the input side and to the motor vehicles to be charged on the output side via connection connections to the charging distributor, wherein after the connection connection is made, the battery status for each connected motor vehicle is determined.

[0004] State of the art

[0005] Devices are known from the prior art with which the charging current from a single charging station for electrically powered motor vehicles can be distributed to multiple motor vehicles via a charging distributor. It is known that the vehicles signal their battery status, for example via an internal resistor that can be switched to different levels depending on the charging current requirement. Furthermore, DE102019217783A1 discloses electrically connecting multiple vehicles to the charging distributor via a separate connection, each connection being assigned a switch that can be used to interrupt the vehicle's charging current tap. If a charging process end signal is received from a first vehicle, the switch of the connection connected to the first vehicle is switched such that this connection blocks the current.The switch of the connection connected to the second vehicle is switched in such a way that this connection is conductive and the charging process of the second car is started. A disadvantage of the prior art, however, is that a switch must be provided for each connection. This increases the costs, complexity and susceptibility to errors in the charging process, particularly when there are multiple connections. In addition, a failure of the switch makes it impossible to use the respective connection without first repairing or replacing the switch. Furthermore, the vehicles are supplied with charging current according to the switching sequence of the switches. This means that if different vehicles are repeatedly connected and unplugged, even a vehicle that has been connected for a long time will still not be supplied with charging current if another vehicle is connected to a different connection.

[0006] Description of the invention

[0007] The invention is therefore based on the object of enabling reliable serial charging of several electric vehicles with only one charging station using the simplest possible technical means and, at the same time, being able to estimate or determine the completion time of the charging process of each vehicle in a comprehensible manner.

[0008] The invention achieves this objective in that the connected motor vehicles are then arranged in series and, starting with the first motor vehicle in the series as the selected motor vehicle, the charging distributor enables this motor vehicle to tap the charging current in a serial charging process by transmitting an enable signal for tapping the charging current exclusively for the selected motor vehicle until the battery status of this motor vehicle corresponds to a target value stored in the charging distributor, whereupon the serial charging process is carried out for the next motor vehicle in the series as the selected motor vehicle. The invention is based on the idea that the possibility of tapping the charging current for a motor vehicle from the connection is not established via a separate circuit, such as a switch, and this connection is thus interrupted to prevent undesired tapping of the charging current.Instead, each of the connected vehicles is continuously connected to the charging distributor for the duration of the connection, but the charging circuit is only closed for one connected vehicle by transmitting the release signal. Although the release signal can be transmitted to all connected vehicles, it is specific to the respective vehicle and only enables the charging current tap for one vehicle in the series until the battery status corresponds to at least a target value stored in the charging distributor. The release signal triggers an internal switching process in the selected vehicle, whereby the connection becomes part of a charging circuit of the vehicle, in which the charging current coming from the charging station via the charging distributor and the connection causes the vehicle's battery to be charged.This enable signal can, for example, be transmitted via an electrical signal that informs the selected vehicle of the available charging current. The battery status can, for example, be determined by a change in an internal resistance in a circuit shared with the charging distributor. If the battery status of the vehicle currently selected in the series does not correspond to the setpoint, the enable signal for this vehicle is transmitted, thereby authorizing this vehicle to tap the charging current. In the simplest case, the setpoint can be just one value, namely "fully charged." Preferably, however, the battery status and setpoint refer to percentage charge values.For example, the battery status can include the charge status of the vehicle's battery as a percentage of its maximum capacity, and the target value can be the lower limit of the charge level of this battery as a percentage of its maximum capacity, for example "at least 20%." In this case, an enable signal for the selected vehicle is transmitted until the battery's charge level is at least 20%. The target value can be specified or changed by an administrator, for example, via an interface on the charging distributor. The sequence of the connected vehicles enables the connected vehicles to be charged in a sequence that is independent of the arrangement of the connections, since the sequence is not determined by mechanical or electronic components. For example, the number of a parking space assigned to a connection can define the place in the charging sequence.The sequence can be updated at specific times, for example, each time a connection is established or disconnected. The vehicles can be charged sequentially, with the charging process stopping when the battery status of all connected vehicles matches the target value. It goes without saying that if a single connected vehicle is connected, this is the first vehicle in the sequence and is charged first. The connection must at least allow the charging current provided by the charging station to be transmitted from the charging distributor to the connected vehicle. In addition, it can also include additional lines for data exchange between the vehicle and the charging distributor.Furthermore, the charging distributor can be in contact with each motor vehicle connected via a connection for the duration of the connection via the communication medium used to transmit the enable signal. The charging distributor can repeatedly determine the battery status of the motor vehicle currently being charged and repeatedly compare it with the target value. According to the invention, the connections can be designed particularly simply and without switches, since all connections can be supplied with charging current and any other signals, and no current or signal separation is necessary for the different connections. This enables the connections to be connected in parallel. Nevertheless, according to the invention, only one motor vehicle is charged at a time, i.e., a serial charging process is carried out. The connections are connected in particular in parallel to a common charging distributor.By transmitting the enable signal for charging current tapping exclusively for the selected vehicle, this vehicle can be allowed to tap the charging current during a serial charging process until the battery status of this vehicle corresponds to a target value stored in the charging distributor. The next vehicle in the series is then charged by transmitting an enable signal for charging current tapping exclusively to this vehicle. The charging distributor therefore only needs to be designed for the maximum charging capacity of one vehicle.

[0009] In order to not only transmit the information to the motor vehicle with the release signal as to whether or not the charging current is permitted to be drawn, but also to easily enable more complex data exchange, it is proposed that the release signal for the charging current be transmitted as a modulated voltage signal. This allows further information to be added to the release signal via modulation and thus transmitted to the motor vehicle. For example, the duty cycle of the pulse width modulation of the signal can be used to communicate the maximum amount of charging current that the motor vehicle is permitted to draw. For example, a pulse width modulation duty cycle of 10 to 85% can correspond to a permitted voltage draw of 6 to 51 amperes, while a pulse width modulation duty cycle of less than 3% signals to the motor vehicle that it is not permitted to draw any charging current.For example, the release signal can include the pilot signal from the charging station and the information as to which motor vehicle is to be released.

[0010] To create the possibility of giving priority to vehicles requiring urgent charging, regardless of the sequence of vehicles, it is proposed that a prioritized connection be provided. After determining the battery status of the vehicle connected to the prioritized connection, the charging distributor interrupts the charging current tap running via another connection and restarts the serial charging process with the vehicle connected to the prioritized connection as the first vehicle in the sequence. As a result of these measures, the vehicle connected to the prioritized connection is always charged first, regardless of the existing sequence of the other vehicles.Provided that connecting to the prioritized connection does not change the sequence of the remaining vehicles, it is still possible to estimate when a specific vehicle in the sequence will be charged. The prioritized charging connection can be intended for vehicles that need to be charged as quickly as possible, such as customer or emergency vehicles, while more charging time is available for vehicles on the regular connections. It goes without saying that while more than one prioritized connection can be provided, a further sequence must then be carried out for the multiple prioritized connections, which is followed by the sequence of the regular connections. The prioritized connection does not have to be physically fixed to one connection; it can change.For example, regular and preferred users can be identified via special authentication at the charging hub, with the connection connected to the vehicle of a preferred user automatically becoming the priority connection. A separate setpoint can be provided for vehicles connected to priority connections.

[0011] While there are a variety of possible ways of queuing vehicles, to ensure that the queuing is transparent at all times and time-efficient for the maximum number of users, the connected vehicles can be sequentially ranked according to the time the connection is established. This means that vehicles connected later will be charged later. This way, when a user connects the connection to their vehicle, they can determine how many vehicles are already connected and thus estimate when their vehicle will be charged. Furthermore, the queuing of vehicles is not predetermined by the spatial allocation of the connection, for example a parking space, so that, with the exception of prioritized connections, no vehicle connected later will be charged first.Since the connected motor vehicles are arranged in sequence according to the time at which the connection is made, a vehicle loses its place in the sequence as soon as the connection is interrupted.

[0012] In order to utilize existing connector and signaling systems and thus keep communication between the charging distributor and the vehicle as simple as possible, it is proposed that the charging distributor convert a pilot signal transmitted by the charging station into the enable signal for tapping the charging current exclusively for the selected vehicle, and that the enable signal be transmitted via the connection points. Thanks to these measures, separate data transmission systems for the enable signal are no longer required. This also allows the use of standard industry connectors, such as CCS Type 2 connectors, for the connection points for the vehicles. These connectors, in addition to a charging current supply, also feature a pilot contact for transmitting a pilot signal to the connected vehicle. This also allows the battery status to be determined via the connection point.The enable signal can be sent to all motor vehicles via all connection points. At the end of the connection point of the selected motor vehicle, the vehicle's charging current tap is initialized based on the specific enable signal. In one possible embodiment, the charging distributor adds an identification signal specific to the selected motor vehicle to the charging station's pilot signal, which typically enables the charging current to be enabled via a modulated voltage signal, in order to obtain the enable signal. Each connection point terminates in a CCS Type 2 connector, which includes a signaling unit. The enable signal is then transmitted via all connection points and reaches the signaling units of all connection points.The signal unit of the connection to which the selected motor vehicle is connected recognizes from the identification signal that the release signal applies to the selected motor vehicle and converts the release signal back into a conventional pilot signal so that the selected motor vehicle receives the same information as if it were directly connected to the charging station.

[0013] To restrict access to selected or all connecting connections, thus preventing unauthorized persons from using the connection and influencing the sequence of connected vehicles, the connection can only be established after user authentication. This user authentication can be performed, for example, via an RFID transponder carried by the user. The connection can only be connected to a vehicle after user authentication has been completed. For example, the connection can be physically locked and released only after user authentication. Prioritized connecting connections or connections assigned to preferred parking spaces can also only be accessible via separate user authentication.Such separate user authentication may cause any connection connected to the motor vehicle associated with the separate user authentication to become the prioritized connection, regardless of the spatial arrangement of the connection.

[0014] The invention also relates to a charging distributor for carrying out a method according to one of the above claims, comprising an input for the charging plug of a charging station, a plurality of connections for supplying charging current to the motor vehicles, a receiver for determining the battery status of a connected motor vehicle, a computing unit for queuing the connected motor vehicles, and a data connection for transmitting an enable signal. The charging plug of the charging station can be electrically connected to the charging distributor via its input. The charging distributor, in turn, can be electrically connected to a plurality of motor vehicles via its plurality of connections. The precise design of the receiver depends on how the battery status of the connected motor vehicles is determined. If a connected motor vehicle emits its battery status, for example, via a wireless signal, the receiver comprises an antenna.Preferably, however, the battery status is transmitted via the connection. This allows the signal indicating the battery status to be further processed by a signal converter connected to the connection as a receiver. The receiver transmits the battery status of the connected vehicles to the computer, which sends the enable signal via the data connection. The enable signal can be transmitted to all vehicles simultaneously, as it only allows the selected vehicle to tap the charging current. For example, each connection can lead to a CCS Type 2 connector that includes a signal unit. The enable signal is then transmitted via all connections and reaches the signal units of all connections.The signal unit of the connection to which the selected motor vehicle is connected recognizes from the identification signal that the release signal applies to the selected motor vehicle and converts the release signal back into a conventional pilot signal so that the selected motor vehicle receives the same information as if it were directly connected to the charging station.

[0015] To further simplify the charging current tap of the vehicles being charged, the connection points can be connected in parallel. Since only the connected vehicle, for which the enable signal for charging current tap has been transmitted, can tap charging current by closing the circuit formed by the connection point, it is not necessary to actively interrupt or control the charging current tap, for example, via switches. For the same reason, the enable signal can also be transmitted via the parallel connection points.

[0016] To increase operational reliability, a storage socket is provided for each connection. The end of the connection, preferably a plug, can be plugged into this storage socket when the connection is not connected to a motor vehicle and thus safely stored. In a preferred embodiment, the charging distributor detects, for example via an electrical circuit closed via the storage socket, that the end of the connection is stored in the storage socket. If not all connection connections are either connected to motor vehicles or stored in the storage sockets, the charging distributor can interrupt the power supply to the connection connections in order to prevent unwanted electrical contact with people or objects and the resulting injuries or damage.To provide the user with relevant information about the charging process, a display for reading the charging status of the connected motor vehicle can be provided for each connection. The charging status can include, for example, information about the expected start and end of the charging process, the current battery status, the position of the connected motor vehicle in the row, or similar information. In a preferred embodiment, the display is attached to a handle or plug located at the end of the connection.

[0017] Brief description of the invention

[0018] The drawing shows an example of the subject matter of the invention.

[0019] Fig. 1 schematically shows the sequence of the method according to the invention and Fig. 2 is a schematic view of an apparatus for carrying out the method according to the invention.

[0020] Ways to implement the invention

[0021] In a method according to the invention for charging several electrically powered motor vehicles 1 via a shared charging station 2, the charging current from the charging station 2 is fed to a charging distributor 4 on the input side in a first step 3. The charging distributor 4 has an input that is compatible with the charging plug of the charging station 2. In a preferred embodiment, the charging distributor 4 can have several inputs for different charging plug types. The charging distributor 4 has several connection connections 5 on the output side, with the exemplary embodiment shown having three connection connections 5. If a connection connection 5 is connected to a motor vehicle 1, the charging current from the charging station 2 can charge the battery of the motor vehicle 1 via the charging distributor 4 and the connection connection 5.In a next step 6, one or more motor vehicles 1 are connected to the charging distributor 4 via the connection connections 5, whereby this step 6 can be carried out at any time during the method. Since the method is trivial for only one connected motor vehicle 1, the description assumes that several motor vehicles 1 are connected to the charging distributor 4. In the next step 7, the battery status of the motor vehicles 1 is determined. The battery status can be transmitted from the motor vehicles 1 to the charging distributor 4, for example, via a radio signal or preferably via the connection connection 5. In the following step 8, the motor vehicles 1 ready to be charged are arranged in a row; this can be done, for example, via the spatial assignment of the connection connections 5 or preferably via the time at which the connection connection 5 is connected to the respective motor vehicle 1.This sequence determines which motor vehicle 1 is charged first and which vehicles are charged next. The sequence can be updated each time a connection 5 is established or disconnected. In step 9, an enable signal is transmitted. This enable signal allows the motor vehicle 1 to tap the charging current, but at most one motor vehicle 1 is charged at any one time. This enable signal is specific to the respective motor vehicle 1, so that the enable signal can be transmitted to all motor vehicles 1, but only the selected motor vehicle begins the charging process. This enable signal causes the charging circuit of the motor vehicle 1 to be closed, so that the charging current from the charging station 2 is supplied to the motor vehicle 1 via the charging distributor 4 and the connection 5 and charges its battery.This release signal can also be sent wirelessly, but preferably via the connection 5, as shown in the present exemplary embodiment. In a preferred embodiment, the release signal is a modulated voltage signal. In step 10, the charging current is supplied to the motor vehicle. This motor vehicle 1 can now tap off charging current until its battery status corresponds to a target value stored in the charging distributor 4. In step 11, the charging distributor 4 registers that the battery status of the vehicle that last received the release signal and was charged in step 10 corresponds to the target value and queries whether another motor vehicle 1 has been connected to a connection 5 or whether the connection 5 to a motor vehicle 1 has been interrupted. If this is the case, the method continues at step 7, since the sequence of the motor vehicles 1 ready to charge must be carried out again in step 8.Although in a simple embodiment a sequence can be created and processed during the charging current tap of the first motor vehicle 1, in the embodiment shown the sequence is updated by the steps performed in step 7. If it is determined in step 11 that the number of connected motor vehicles 1 has not changed, the process continues with step 9. If it is determined during the course of the method that the battery status of each of the connected motor vehicles 1 corresponds to the target value, no further enable signal is sent until the method continues again at step 6 by connecting a connection to a motor vehicle.

[0022] In order to give priority to certain vehicles, a prioritized connection can be provided. If a motor vehicle 1 is connected to a prioritized connection in step 12, the battery status of this motor vehicle 1 is immediately checked in this step 12. If the battery status of this motor vehicle 1 does not correspond to the target value, the method is interrupted immediately from step 7 and continued with the vehicle 1 connected to the prioritized connection at step 8, wherein the vehicle 1 connected to the prioritized connection is set as the first motor vehicle 1 in the series. Step 12 can be carried out at any time during the ongoing method, whereby any charging current tapping of another motor vehicle 1 taking place at this time is also interrupted.

[0023] To restrict access to the connection points, in an optional process step 13, the connection point 5 can only be established after user authentication has been entered. This can be done, for example, using an RFID transponder.

[0024] As can be seen from Fig. 2, a charging distributor for carrying out the method according to the invention comprises an input 14 for the charging plug of a charging station 2. The charging station 2 is supplied with power via the power grid 15. The charging current, which can be tapped via the input 13, can be supplied to the connected electric motor vehicles 1 via a plurality of connection connections 5 arranged on the output side. The connection connections 5 for tapping the charging current are usually multi-pole. In the exemplary embodiment shown, the connection connections 5 each lead to a CCS Type 2 plug 16. The respective poles are 5a for the DC+, 5b for the DC-, 5c for the protective conductor, 5d for the proximity contact, and 5e for the pilot contact. For reasons of clarity in the drawing, the corresponding reference numerals have only been entered for one connection connection 5.In this case, the pilot signal, which is fed into the charging distributor 4 via the pilot contact of the charging station 2, is converted into the enable signal by the charging distributor 4 adding an identification signal specific to the selected motor vehicle to the pilot signal. In this exemplary embodiment, the plug 16 comprises a signaling unit. If the enable signal is transmitted via all connection points 5, this signaling unit in the plug 16 checks whether the identification signal of the enable signal matches the motor vehicle 1 connected to the plug 16 and, if there is a match, enables the charging current tap, preferably digitally. For example, the connection points 5 can be numbered consecutively, with the identification signal specifying the motor vehicles 1 via the number of the respective connected connection point 5.Once the agreement has been reached, the signaling unit can convert the release signal for the selected motor vehicle 1 back into a pilot signal, so that the signal received by the selected motor vehicle 1 corresponds at all poles to the signal the vehicle would also receive if it were directly connected to a charging station 2. The battery status of the motor vehicle 1 can be determined via the signaling circuit, which connects the motor vehicle 1 to the charging distributor 4 via the pilot contact 5e and the protective conductor 5c, analogously to the signaling circuit directly connected to the charging station 2. For this purpose, the motor vehicle 1 can, as described above, have an internal, adjustable resistor that is connected to the signaling circuit, and one of the adjustable resistance values ​​signals the battery status.An analog-to-digital converter in the charging station 4 is connected to this signaling circuit and thus receives the battery status of the motor vehicles 1 and transmits it to a processing unit 17. This processing unit 17 can be provided in the charging distributor 4 and, among other things, can sequence the connected motor vehicles 1, determine which motor vehicle 1 is to receive an enable signal and when, and process the data from the signaling circuits. One of the connection points 5 shown can be a prioritized connection point, which, as explained above, is treated separately.

Claims

Patent claims 1. Method for charging several electrically powered motor vehicles (1) via a common charging station (2), in which the charging current of the charging station (2) is supplied (3) to a charging distributor (4) on the input side and is supplied to the motor vehicles (1) to be charged on the output side via connection connections (5) with the charging distributor (4), wherein after the connection (6) of the connection connection (5), the battery status for each connected motor vehicle (1) is determined (7), characterized in that the connected motor vehicles (1) are then arranged in series (8) and the charging distributor (4), starting with the first motor vehicle (1) in the series as the selected motor vehicle (1), enables this motor vehicle (1) to tap the charging current exclusively for the selected motor vehicle (1) in a serial charging process by means of a transmitted enable signal for tapping the charging current (9),until the battery status of this motor vehicle (1 ) corresponds to a target value stored in the charging distributor (4), whereupon the serial charging process is carried out for the next motor vehicle (1 ) in the series as the selected motor vehicle (1 ).

2. Method according to claim 1, characterized in that the enable signal for tapping the charging current is transmitted as a modulated voltage signal.

3. Method according to claim 1 or 2, characterized in that a prioritized connection is provided and the charging distributor (4) interrupts the charging current tapping running via another connection (5) after determining the battery status of the motor vehicle (1) connected to the prioritized connection and the serial charging process is restarted with the motor vehicle (1) connected to the prioritized connection as the first motor vehicle (1) in the series.

4. Method according to one of claims 1 to 3, characterized in that the connected motor vehicles (1) are consecutively arranged according to the time of connection of the connection connection (5).

5. Method according to one of claims 1 to 4, characterized in that the charging distributor (4) converts a pilot signal transmitted from the charging station (2) into the release signal for tapping the charging current exclusively for the selected motor vehicle (1) and the release signal is transmitted via the connection connections (5).

6. Method according to one of claims 1 to 5, characterized in that the connection (5) is established only after user authentication.

7. Charging distributor (4) for carrying out a method according to one of the above claims, comprising an input (14) for the charging plug of a charging station (2), a plurality of connection connections (5) for supplying charging current to the motor vehicles (1), a receiver for determining the battery status of a connected motor vehicle (1), a computing unit (17) for queuing the connected motor vehicles (1) and a data connection for transmitting an enable signal for tapping the charging current exclusively for a selected motor vehicle.

8. Charging distributor according to claim 7, characterized in that the connection connections (5) are connected in parallel to one another.

9. Charging distributor according to claim 7 or 8, characterized in that a storage socket is provided for each connection (5).

10. Charging distributor according to one of claims 7 to 9, characterized in that a display for reading the charging status of the connected motor vehicle (1) is provided for each connection (5).

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