Charging arrangement for an electric vehicle and operating method for such a charging arrangement

Abstract

The invention relates to an operating method for a charging arrangement for an electric vehicle, wherein the charging arrangement comprises at least one charging station (10) and an administration unit (30). The method comprises the following steps: - Providing tariffs for a charging process at the at least one charging station (10); - storing and archiving the tariffs provided by a tariff server (40); - Providing a public access option to retrieve the current and archived tariffs from the tariff server (40); - sending a first tariff request from the administration unit (30) to the tariff server (40) to retrieve a current tariff for the at least one charging station (10); - carrying out the charging process by the at least one charging station (10) and detecting an amount of energy transferred during the charging process by an energy meter (12) of the at least one charging station (10); - Creation of a billing document by the administration unit (30) based on the previously retrieved tariff. The invention further relates to a charging arrangement with at least one charging station (10). The charging arrangement is characterized by a tariff server (40) that stores and archives a tariff applicable at the at least one charging station (10) and is configured to provide current and archived tariffs upon request.

Description

The invention relates to an operating method for a charging arrangement for an electric vehicle, wherein the charging arrangement comprises at least one charging station and an administration unit. The invention further relates to a charging arrangement having at least one charging station.Charging stations are used for charging traction batteries of electric vehicles, to which charging stations an electric vehicle is connected by means of a suitable charging cable or is connected via an inductive coupling. Electrical energy in the form of direct current or alternating current is then generally transmitted from the charging station to the electric vehicle, and under certain circumstances also from the energy vehicle to the charging station in order to support the energy supply network. Such charging stations are known in the form of possibly self-supporting charging columns or as so-called "wall boxes" for wall mounting.If charging stations are to be accessible to a plurality of persons, i.e. are set up in the public room, for example, or in the area of multi-family houses or on company sites, it is necessary to be able to unambiguously allocate the amount of energy delivered or absorbed to a user of the charging station. Furthermore, the amount of energy delivered or absorbed is to be detected in a reproducible and right-handed manner and presented to the user for checking. Rights bases are to be taken into account if necessary; for example, the requirements of the calibration right must be observed in Germany. Finally, payment modalities are likewise to be defined transparently in advance. This includes, for example, the fact that a user must be informed in a reproducible manner about an energy price of the subsequent charging process before the beginning of a charging process.Charging arrangements have become established on the market in which use of a charging station is only possible when a user has logged in beforehand with his payment information to an operator of the charging station and has, for example, an identification card ("charging card") created specifically for this use. However, this procedure greatly restricts users, since it is complicated and sometimes associated with high monthly basic fees to keep a respective charging card available for a multiplicity of different systems which have become established on the market. Even if an electric vehicle is used in a large radius, there is often the situation that an available charging station cannot be used because the matching charging card is not present.In order to make charging stations usable independently of a prior report, a charging station for electric vehicles is known, for example, from the publication EP 3 971 023 A1, which charging station comprises a payment card terminal with which a credit or balance card can be read in. An identification code is then created in the charging station, which identification code comprises at least a part of a credit card number or a gro account number. Furthermore, count values of the amount of energy supplied during a charging process are measured in the charging station and, based on the count values and the identification code, a record for the billing of the charging process is created, which record is stored and can be downloaded by the user for checking purposes. In order to achieve increased security, it is further provided to digitally sign the count values of the energy quantity and the identification code, optionally with an additional identification of the charging station and a piece of time information relating to the charging process, in the charging station, so that the billing record is tamper-proof for the further processing.The method is flexible since, independently of a prior registration and establishment of a customer account with the operator of the charging station, the latter can be used with credit, debit or Giro card. However, the method cannot be implemented with charging stations already installed, which do not have corresponding equipment with a payment card terminal.It is therefore an object of the present invention to provide a charging arrangement and an operating method of the type mentioned at the beginning which are flexible in use and which can also be implemented as retrofit solutions with charging stations which do not have an integrated payment card terminal.This object is achieved by an operating method and a charging arrangement having the features of the respective independent claim. Advantageous embodiments and developments are the subject matter of the dependent claims.The invention is explained in more detail below with reference to an exemplary embodiment with the aid of figures. The figures show: FIG. 1 shows a schematic illustration of an exemplary embodiment of a charging arrangement; and FIG. 2 is a flow diagram of an operating method for a charging arrangement.FIG. 1 shows an exemplary embodiment of a charging arrangement according to the invention in the form of a block diagram by way of example. In this exemplary embodiment, the charging arrangement comprises a charging station 10, a payment card terminal 20, an administration unit 30 and a rate server 40. Communication can also take place via the network 50 to other units, not explicitly shown here. The Internet can in particular serve as the network 50. In alternative embodiments, it is also possible to perform a data exchange between two or more of the units shown, i.e. for example between the charging station 10 and the payment card terminal 20 or between the payment card terminal 20 and the administration unit 30, via a data connection operating independently of the network 50. If necessary, such a data connection can also be a wired point-to-point connection.The charging station 10 has a control unit 11 via which communication with the network 50 also takes place. The charging station 10 further has an energy amount meter 12 which comprises a signature unit 13. In alternative embodiments, the signature unit 13 can also be arranged inside the charging station 10 externally of the energy amount meter 12.Further components which the charging station 10 necessarily or optionally has are not illustrated for reasons of clarity. Such components included, for example, a charging connection for connecting the charging station 10 to an electric vehicle to be charged. A charging socket or a charging cable with charging plug attached fixedly to the charging station 10 can serve as the charging connection. Furthermore, components for supplying energy to the charging station 10 are not shown, in particular for supplying an alternating current, which is generally three-phase and is transmitted either as alternating current or, after rectification, as direct current to the electric vehicle via the charging connection. Alternatively, the charging station 10 can also be connected to a DC voltage bus for its energy supply. In connection with the transmission of the charging current to the electric vehicle, switching and safety elements are also arranged in the charging station 10, for example earth leakage circuit breakers and overcurrent and possibly overvoltage fuses. For controlling the charging process, a charging controller is provided, which can be implemented in the control unit 11 or in a separate unit.Furthermore, the charging station 10 can have display and / or operator control elements, for example a screen, in particular a touchscreen, for displaying information relating to the charging process or for displaying a state of the charging station 10 and / or of the charging process.The charging station 10 can be designed as a charging column, optionally a self-supporting charging column, or can also be suitable for wall mounting, that is to say can be designed as a "wallbox".In the exemplary embodiment of FIG. 1, a payment card terminal 20 is present separately from the charging station 10, which payment card terminal is preferably located in the vicinity of the charging station 10. It can be provided to provide a payment card terminal 20 for a plurality of charging stations 10 set up adjacently. The payment card terminal 20 comprises a control unit 21 coupled to a card reader 22, to a display unit 23, e.g. a display, and to an operating unit 24, e.g. a keypad. The components mentioned, i.e. the control unit 21, the card reader 22, the display unit 23 and the operating unit 24, can be separate elements which are connected to one another via cables. It is also conceivable to integrate all or some of the components in a compact unit.The pay card terminal 20 makes it possible to read out information stored on a card by means of the card reader 22. Depending on how the information is stored on the card, the card reader 22 can be a chip or magnetic card reader into which the card is inserted, or a contactless card reader which reads information wirelessly from the card. For this purpose, the card can be designed, for example, as an RFID (Radio Frequency Identification) card or can have an NFC (Near Field Communication) chip. The card reader 22 may also be suitable for different card formats or there may be multiple card readers 22 suitable for different cards. For example, a screen (display) may be used as the display unit 23 to notify the user of instructions as to which steps are expected next. The operating unit 24 can comprise a keyboard, with which e.g. a secret number (PIN) can be input.While in the example shown the charging station 10 and the payment card terminal 20 are separate units, it is likewise conceivable for the payment card terminal 20 to be integrated into the charging station 10. If a plurality of charging stations 10 are present, each can be provided with a payment card terminal 20. However, it is also conceivable to arrange a payment card terminal 20 in one of the charging stations 10, which is also used in conjunction with the other charging stations 10.It is important to note that the payment card terminal 20 can be arranged and designed separately from the charging station 10, which makes it possible to use charging stations which are already present and do not have a payment card terminal within the scope of a charging arrangement according to the invention in the course of a retrofitting solution. In principle, the method according to the invention can also be carried out with a charging arrangement without a payment card terminal if an identity of the user is determined in a different manner and information on how payment of the charging process takes place (also referred to below as payment information) is stored beforehand. For example, the user can be identified indirectly via a vehicle identifier, which can be read in, for example, via a data exchange with the electric vehicle via the charging connection or via an automatic evaluation of camera recordings of a license plate ("license plate").In the method according to the invention, the administration unit 30 and the rate server 40 can advantageously be arranged separately from both the charging station 10 and the payment card terminal 20.The administration unit 30 and the rate server 40 each comprise one or more (web) servers 31, 41 which optionally execute redundant and distributed (web) services.The administration unit 30 coordinates the operation of the charging arrangement and thereby also acts in a controlling manner on various components, for example the charging station 10. The rate server 40 has in particular a logging function and archives rate, also referred to below as price information, in order to be able to understand at which time which rate they have valid or have considered. For this purpose, the rate server has a data memory 42 which can comprise a file system and / or a database, for example. The data store 42 is preferably provided with protection and protocol mechanisms, e.g. journaling, which renders changes to data made comprehensible. Thus, it can function as a trusted entity in view of the announced prices.Preferably, the rate server 40 is a unit independent of the administration unit 30. It can also be used in particular by different administration units 30, including different suppliers and operators of charging arrangements.Details of the functions of the administration unit 30 and of the rate server 40 are explained in greater detail below in conjunction with FIG. 2.An embodiment of an operating method according to the invention for a charging arrangement is shown in FIG. 2 in the form of a flow chart. The operating method illustrated can be carried out, for example, with the charging arrangement according to FIG. 1 and is described below by way of example with reference to the charging arrangement of FIG. 1.The operating method comprises method steps S 1 to S 18 and S 100-S 101, the representing symbols of which are arranged horizontally in FIG. 2 such that they can be assigned to the various units in which they are executed, specifically the charging station 10, the payment card terminal 20, the administration unit 30 and the rate server 40.In the first step S 1, the user connects his electric vehicle to the charging station 10. The charging station 10 can be a single charging station 10 or else one of a plurality of charging stations 10 to which the payment card terminal 20 is jointly assigned.The charging station 10 then blocks charging plugs or charging cables from being removed, checks compatibility with the connected electric vehicle and determines possible charging parameters, for example a maximum permissible charging current or a maximum permissible charging power. The control unit 11 of the charging station 10 then sends a message about the connection of the electric vehicle that has taken place to the administration unit 30.The message includes a time value representing date and time displayed at the charging station 10. The date and time can be displayed, for example, on a display of the energy amount counter, which can generally be seen at the charging station 10. The date and time displayed at the charging station can serve as a reference value, on the basis of which a guarantee of price is granted to the user for the charging method. This can be communicated to the user by a corresponding notification at the charging station 10. The message can also comprise further information about the planned charging process. It is preferably created according to the specifications of the OCPP (open charge point protocol) standard.In addition, the user at the charging station 10 can be called a web address via which he can see current and past prices. This is possible at any time and is shown in the flow chart of FIG. 2 in steps S 100 and S 101. In step S 100, the user sends a request, for example via a web browser, to the rate server 40, which the latter receives in step S 101. The rate server 40 then retrieves a current rate for the charging station 10 from its data store 42 and sends it back to the web browser where it is displayed to the user. As a rule, the rate server 40 is used by a plurality of charging stations, which can also have different rates. In order to be able to display the tariffs of the charging station 10 to the user, a unique identifier of the charging station 10, for example a charging station ID, can be contained in the web address provided.The transmitted message is received and processed by the administration unit 30 in a step S 3.In particular, in step S 3, the administration unit 30 queries current price information for a charging process at the charging station 10, which applies at the time according to the time value, from the rate server 40.In the exemplary embodiment shown in FIG. 2, the plugging of the electric vehicle onto the charging station 10 in step S 1 and the subsequently transmitted message in step S 2 initiate the price request by the administration unit 30 in step S 3. In alternative embodiments of the method, the price request can also be initiated in a different manner. For example, it is conceivable that the user actuates an operating element at the charging station 10 or also at the payment card terminal 20 in order to start a price request. A message comparable to that in step S 2 is then sent from the charging station 10 or the payment card terminal 20 to the administration unit 30 in order to retrieve the current price information from the rate server 40 in the following step S 3. The message then transmitted can also comprise a time value.The rate server 40 receives this request of step S 3 in step S 4 and determines a current rate for the scheduled charging process. This current rate is also referred to below as first price information. The entry time of the request to the rate server 40 in step S4 is regarded as a relevant time for the first price request. Furthermore, a unique identifier for the pending operation is created, which is referred to below as transaction ID.The rate server 40 preferably collects price information regularly, possibly from different sources for possibly different operators of charging arrangements, so that it has knowledge about current prices at all times. The rate server 40 also stores past prices together with a period of validity in its data memory 42 so that a valid price can be specified for each current or past time.In addition, the rate server 40 stores concrete requests such as the rate request obtained in step S4 at least until such concrete operation is completed. For this purpose, the first price information is archived in the data memory 42 together with the information obtained about the scheduled loading process, the transaction ID and a first time stamp which specifies the entry time of the request. The first time stamp is based on a system time of the rate server 40, which is synchronized with an official time standard as reliably as possible. If a time value of the charging station 10 has also been received in step S 4, provision can be made for a deviation at the system time of the rate server 40 to be determined and stored as well.Furthermore, the first price information and the transaction ID are sent from the rate server 40 to the administration unit in a next step S5 and are forwarded from there to the payment card terminal 20 in a following step S6. The transmission can take place, for example, according to the MQTT (Message Queuing Telemetry Transport) protocol. However, other network-suitable protocols can also be used. The transmission can take place via the administration unit 30, as is illustrated in FIG. 2, or else directly from the rate server 40 to the payment terminal 20.The pay card terminal 20 receives the first price information in step S7 and displays relevant information from the record on the display unit 23. The information contains the determined prices for the charging process, for example in the form of a basic price for the process and an energy price which specifies the costs per kilowatts hour (kWh). In particular, if the payment card terminal 20 is assigned to a plurality of charging stations 10, a unique identifier of the charging station 10 is also displayed. Further preferably, an amount to be reserved is displayed, which must be ensured by the customer and the payment service provider before the beginning of the charging process in order to start the charging process at all. In credit card payment, provision can be made, for example, to reserve a maximum amount which a user then enables for the pending charging process with respect to his credit card provider.Furthermore, the user is asked with the information on the display unit 23 to select his payment options by inserting a payment card, for example a credit card, a debit card or a Giro card, into the card reader 22 or by holding in readiness the payment card or an equivalent medium, for example a smartphone with an NFC (Near Field Communication) interface.The method continues by the user following the latter in step S 7 and communicating his payment information to the payment card terminal 20 by inserting or holding the payment card (or the equivalent medium) in or in front of the card reader 22. Alternatively, the user can abort the process at this point, which is not explicitly shown in the flow diagram of FIG. 2. In the event of a break, corresponding information is sent to the administration unit 30, which in turn informs the charging station 10 in order to release the charging plug or the charging cable again.Furthermore, provision can be made in step S 7 to request contact data of the user. The contact data can be, for example, a telephone number or an email address, which the user can enter via the operating unit 24 and which can subsequently (cf. step S 14) be used to send an accounting record to the user. Alternatively, after this or one of the subsequent steps, a further web address can be provided, via which the billing receipt can be later called up. The web address can be displayed, for example, as a QR (Quick Response) code, which the user can photograph comfortably with his mobile telephone.In a following step S9, the provided information about the payment card is read in by the card reader 22, in particular a card or account number, and further processed in the payment card terminal 20. In addition, it may be necessary to input a secret number (PIN) to the operation unit 24. Based on the information from the card reader 22, optionally from the operating unit 24 and the maximum amount to be reserved, a request is then sent to the payment service provider located behind the payment card of the user in order to release the transaction and reserve the provided amount.A response of the payment service provider is evaluated by the payment card terminal 20 in a step S10. When the transaction is approved by the payment service provider, the payment card terminal 20 sends a corresponding message to the administration unit 30. In this case, information is again sent to the administration unit 30, which either archives or discards the process and which notifies the charging station 10 to abort the process with respect to the electric vehicle as well and to release the charging plug or charging cable for removal.The release sent to the administration unit 30 in step S 10 is received there in step S 11.It is conceivable that the administration unit 30 assigns a further identifier to the process in step S 3, S 6 or S 11, which is necessary, for example, for reasons of compatibility with already existing operating methods. Such an identifier is referred to as a process ID hereinafter. If such an operation ID has been created, it is notified to the rate server 40 in step S11. It receives a corresponding message in step S12 and stores the transaction ID, associating it with the transaction ID. An interrogation of the information stored on the rate server 40 regarding the process created in step S 4 can then take place alternatively via the transaction ID or the process ID.Furthermore, in step S 11, the administration unit 30 sends a message to the charging station 10 in order to start the charging process. Preferably, a value of a maximum amount of energy to be delivered, e.g. indicated in kWh, covered by the maximum amount is also transmitted. This message may in turn be formed according to the OCPP standard.If, in alternative embodiments of the method, the first price request was not initiated by connecting the electric vehicle to the charging station in step S 1, the user at the latest now connects the electric vehicle to the charging station 10. For this purpose, it can be requested, for example, by a corresponding message on the display unit 23 of the payment card terminal 20.The charging station 10 then starts the charging process in a step S 13, which includes, for example, detecting a counter reading of the energy amount counter 12 when the charging process starts.The charging process is carried out until it is ended in a step S 14, whereupon a further value of the energy amount counter 12 is determined. The amount of energy delivered results from the difference between the counter values of the amount of energy counter 12 determined in steps S 13 and S 14. It is noted that the method can proceed analogously if energy is not drawn from the charging station 10 but rather is emitted by the electric vehicle.After the end of the charging process, the charging station 10 sends a data record containing information about the charging process that has been completed to the administration unit 30, which data record contains, for example, a data tuple containing identifiers of the charging station 10 and information about the starting time and the end time of the charging process that is carried out and in particular the information about the energy quantity that is drawn from the energy quantity counter 12. In addition, the data tuple can contain the charging station ID and a further identifier which identifies the actual charging process and which can be generated, for example, by the charging station 10. This identifier is referred to as charging process-10 below.The data tuple is usually generated in the charging station 10 in accordance with calibration law by the energy amount meter 12 itself and digitally signed in its signature unit 13. In particular, the energy information is thus contained in the data tuple in a tamper-proof manner. Conventional and known asymmetric encryption methods can be used for the digital signature, for example RSA (Rivest-Shamir-Adleman). In an advantageous embodiment, the data tuple can be formed according to the OCPP standard as a so-called open charge metering format (OCMF) string.In step S 15, the information received from the administration unit 30 is further processed from the data record or the data tuple. In particular, the amount of energy transmitted in the charging process is read out of the data tuple and, if appropriate, verified with the aid of a public key of the signature unit 13.Further, another time value corresponding to the start or end time of the charging operation according to the data tuple is determined, and the charging operation ID is read out.The administration unit transmits the charging process ID to the rate server 40 in step S 15 and makes a second price request, which comprises the further time value and optionally the amount of energy transmitted, to the rate server 40.The rate server 40 receives this request in step S 16 and, depending on the embodiment of the method, determines either second price information that applies at the current point in time according to the system time of the rate server 40 or second price information that has credited at the point in time indicated by the further time value. It can be provided that the rate server 40 compares the first and second price information and selects from both the price information which leads to the most favorable total price for the charging process. If the total price is composed of a basic price and a price per energy amount, for example per kilowatts hour (kWh), the amount of energy transmitted is taken into account in this case. If both price information items are identical in content, the first price information item is selected.It can also be provided that the rate server 40 checks the information received in step S 16 for its plausibility. For example, the charging station ID included may be compared with that notified at the first request in step S 4. It is also possible, if appropriate, to compare time values received in step S 4 and, if appropriate, their deviation at the system time of the rate server 40 with corresponding time values and, if appropriate, deviations from the data tuple in order to plausibly check that the charging process described behind by the data tuple is actually the one at which the transaction was applied in step S 4.For documentation, the second price information is archived in the data memory 42 together with the obtained information about the charging process carried out and preferably also an indication as to which price information was selected. The received load ID is also stored by the rate server 40 and assigned to the transaction ID. An interrogation of the information stored on the rate server 40 regarding the process carried out in step S 4 can then alternatively also take place via the charging process ID.The selection of the price information to be used is thus based entirely on a comprehensible basis: the first time stamp reflects the time of the first rate query and corresponds in some cases to the date and time that the user has viewed at the charging station 10 himself. The second time value was provided by the energy quantity counter 12, which is generally formed and certified in accordance with calibration right and is correspondingly trusted. It is available in a manner such that it is virtually tamperproof on the basis of the signature of the signature unit 13 of the energy amount meter 12. The price applicable at a specific point in time is trusted by the permanent storage on the data memory 42. This applies in particular because the price information can be seen publicly from the data memory 42, e.g. via a web page which is provided by the server 41 and the address of which has been pointed out, e.g. at the charging station 10.The public visibility in steps S100 and S101 can effectively provide independent control, which increases the level of trust of the rate server 40. Depending on the method status, a general request can be made with the charging station ID and a time, or a specific transaction can also be called up by specifying the transaction ID, the process ID and / or the charging process ID.The rate server 40 can also achieve a high level of trust in that the programs running on it (i.e. its software) are designed to be tamperproof per se, for example by stored checksums or hash values. The software is preferably tested and certified in this regard by monitoring institutions.The selected price information is sent from the rate server 40 to the administration unit 30 in a following step S17.The administration unit 30 receives the selected price information in step S 18 and determines a total price for the charging process to be paid based on the data from the data tuple, i.e. for example the OCMF string, and the selected price information. It can be provided that the ascertained total price is then sent by the administration unit 30 in the form of a further message to the payment card terminal 20, which forwards the total price to be paid to the billing service provider in order to thus charge the payment card represented by the user in step S 8 in the final form and to complete the payment process.The administration unit 30 furthermore creates a billing record which can then be sent, for example, to a billing system of the operator of the charging arrangement. Based on the billing record, the operator of the charging arrangement can make a billing for the payment service provider if this has not been effected directly by the payment card terminal 20, as described above.The billing receipt can also be sent to the user himself if the latter has specified a telephone number in step S 8 or an e-mail address or other contact data via which preferably electronic delivery can take place. Alternatively or additionally, a further data address, which may have been presented beforehand, can be used to download the billing receipt.In the example described above, the administration unit 30 sends control instruction directly to the charging station 10. In an alternative embodiment of the method, instead, communication from the administration unit 30 to the charging station 10 for controlling this charging station 10 can take place via a central control device of the charging arrangement, in particular if the charging arrangement comprises a plurality of charging stations 10.In an advantageous embodiment, subsequent verification steps are provided for checking the billing record received from the user.For this purpose, a transparency service is provided, for example in the form of a web application or a web page, which offers the option of loading or uploading the billing receipt. The transparency service checks the integrity of the accounting data record on the basis of a publicly available key of the signature unit 13.Furthermore, the transparency service can check whether the information contained in the billing record is correct in itself. In particular, the energy amount information acquired in steps S 13 and S 14 of the diagram of FIG. 2 and signed by the energy amount counter 12 in the signature unit 13 can be read out and compared with the energy amount on the basis of which the total price was ascertained.List of reference characters10 Charging station 11 Control unit 12 Energy amount meter 13 Signature unit 20 Payment card terminal 21 Control unit 22 Card reader 23 Display unit 24 Operation unit 30 Administration unit 31 Server 40 Rate server 41 Server 42 Data storage 50 Network S 1-S 18 Method step S 100-S 101 Method stepReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 3 971 023 A1

[0005]

Claims

Operating method for a charging arrangement for an electric vehicle, wherein the charging arrangement comprises at least one charging station (10) and an administration unit (30), comprising the following steps: - providing tariffs for a charging process at the at least one charging station (10); - storing and archiving the provided tariffs by a tariff server (40); - providing a public access facility to retrieve the current and archived tariffs from the tariff server (40); - sending a first tariff request from the administration unit (30) to the tariff server (40) for retrieving a current tariff for the at least one charging station (10); performing the charging process by the at least one charging station (10) and detecting an amount of energy transmitted during the charging process by an amount of energy meter (12) of the at least one charging station (10); creating a billing record by the administration unit (30) based on the previously retrieved tariff.Operating method according to Claim 1, in which, with the retrieval of the current rate by the administration unit (30), a unique transaction ID is generated by the rate server (40), which transaction ID is stored together with the current rate and a first time stamp by the rate server (40).Operating method according to Claim 1 or 2, in which the at least one charging station (10), after the charging process, creates a data record which comprises the recorded energy quantity and a charging process ID and which is sent to the administration unit (30).Operating method according to Claim 3, in which the charging process ID is sent from the administration unit (30) to the rate server (40) and is linked to the transaction ID by the rate server (40).Operating method according to claim 3 or 4, wherein the administration unit (30) sends a second rate request to the rate server (40) in order to retrieve a rate for the at least one charging station (10).Operating method according to Claim 5, in which the two tariffs retrieved are compared and the billing record is created on the basis of one of the tariffs as a function of a result of the comparison.Operating method according to Claim 6, in which the plan which leads to a more favorable overall price of the charging process is used as the basis for the billing record.Operating method according to one of Claims 1 to 7, in which, before the transmission of the first rate request, the electric vehicle is connected to the at least one charging station (10), and a message relating to the connection of the electric vehicle is transmitted from the at least one charging station (10) to the administration unit (30).Operating method according to Claim 8, in which the message relating to the connection of the electric vehicle comprises a charging station ID of the at least one charging station (10) and / or a time currently displayed by the charging station (10) in the form of a time and date value, wherein the charging station ID and / or the time and date value is transmitted from the administration unit (30) to the rate server (40) with the first rate request.Operating method according to Claims 2 and 9, in which the information transmitted by the administration unit (30) is linked to the transaction ID by the rate server (40).Operating method according to one of Claims 1 to 10, in which payment information is queried and read in by the user by a payment card terminal (20) before the charging process is started.Operating method according to Claim 11, in which, after reading in, the payment information is verified by a request at a payment service provider and the loading process is carried out only if the payment information is confirmed.Operating method according to Claim 11 or 12, in which the current rate is sent to the payment card terminal (20) and is at least partially displayed there.Operating method according to one of Claims 1 to 13, in which the rate server (40) is separate and independent from the administration unit (30).Operating method according to one of Claims 1 to 14, in which the billing record is transmitted to a billing center.Operating method according to one of Claims 1 to 15, in which the user is provided with a further access possibility via which the billing record can be called up.Charging arrangement for an electric vehicle, comprising at least one charging station (10), characterized in that the charging arrangement comprises a rate server (40), which stores and archives a rate applicable at the at least one charging station (10) and which is configured to provide current and archived rates in response to a request.Charging arrangement according to claim 17, wherein a web address is provided at the at least one charging station (10), via which current and archived tariffs can be called up by the tariff server (40).Charging arrangement according to claim 17 or 18, comprising an administration unit (30) for controlling a charging process at the at least one charging station (10), wherein the administration unit (30) is configured to request a rate for a charging process from the rate server (40).Charging arrangement according to Claim 19, which is designed to carry out a method according to one of Claims 1 to 16.

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