Charging system and charging method for an electrical energy storage device of an electrically powered vehicle

Abstract

The invention discloses a concept for simplified and ubiquitously applicable authentication and authorization of an electrically powered vehicle being charged at a charging station of a charging system and user, as well as charging stations. For this purpose, it is proposed that the vehicle's original equipment manufacturer (OEM) install a two-part, unique alphanumeric identification key in the vehicle's control unit, transmit a first part of the identification key in a charging request via the charging station to an authentication authority, and have the authentication authority compare the transmitted first part with a verification instance of the identification key provided to the authentication authority by the OEM.The second part of the identification key is used for a challenge-response procedure in which the authentication authority transmits a nonce assigned to a verification instance of the second part to the vehicle's control unit, which, for successful authentication and authorization of the charging process, encrypts the nonce with the second part of the identification key stored in the vehicle's control unit and sends it back to the authentication authority.

Description

Technical area

[0001] The present invention relates to a method for operating a stationary electric charging station for vehicles having at least one electric drive motor, wherein the vehicle is electrically connected to the charging station to carry out a charging process, and wherein an authorization to electrically charge the vehicle is checked by the charging station. State of the art

[0002] Vehicles that are fully or at least partially electrically powered have what's known as a traction battery. This traction battery serves as an electrical energy storage device and provides the electrical energy required to propel the vehicle.

[0003] With the increasing number of vehicles equipped with an electric drive motor, especially electric vehicles with only electric drive motors and hybrid vehicles, which have both an electric drive motor and a conventional internal combustion engine, the need for charging stations to supply the vehicles with electrical energy is increasing. To ensure a smooth charging process and to prevent unauthorized vehicles from being supplied with electrical energy, solutions are necessary that allow verification of the vehicle's authorization to conduct a charging process at the charging station.

[0004] At publicly accessible charging stations, charging processes must be authorized, either via an automatic authorization protocol according to ISO 15118 or via manual activation by the user of the vehicle being charged. Automatic authorization processes according to the ISO 15118 protocol require the installation and verification of many different certificates with different validity periods and certification authorities. This involves significant installation effort, updating effort, and large storage requirements.

[0005] For example, Shuaib, E. Barka, JA Abdella, and F. Sallabi, "Secure charging and payment protocol (SCPP) for roaming plug-in electric vehicles," 2017 4th International Conference on Control, Decision and Information Technologies (CoDIT), describe charging and billing protocols for communication between electric vehicles and charging station operators. Publication EP 4 072 180 A1 concerns the authentication of a user of an electric vehicle at a charging point to charging contract partners using authentication means with stored multifunctional identification features. Disclosure of the invention

[0006] The present invention provides a charging system and a charging method for electrical energy storage devices of electrically powered vehicles having the features of the independent patent claims. Further advantageous embodiments are the subject of the dependent patent claims.

[0007] A charging system for an electrical energy storage device of an electrically powered vehicle comprises a charging station with a charging station control unit and an authentication point. The charging station is designed to read a first part of a unique alphanumeric identification key assigned by an original equipment manufacturer of the electrically powered vehicle for the vehicle to be charged at the charging station and transmit it to the authentication point.The authentication point is designed to compare the transmitted first part of the identification key with a verification instance of the identification key provided to the authentication point by the original equipment manufacturer, to send a nonce associated with a second part of the verification instance of the identification key provided by the original equipment manufacturer to a control unit of the vehicle via the charging station using a challenge-response protocol, and to enable the charging station to charge the vehicle if the control unit of the vehicle returns the nonce correctly encrypted with the second part of the identification key stored in the control unit of the vehicle to the authentication point.

[0008] A charging method for an electrical energy storage device of an electrically powered vehicle comprises the steps of reading a first part of a unique alphanumeric identification key of the vehicle to be charged at a charging station, which key is assigned by an original equipment manufacturer of the electrically powered vehicle, by a charging station control unit of the charging station, transmitting the read first part of the identification key to an authentication authority, comparing the transmitted first part of the identification key with a verification authority of the identification key provided to the authentication authority by the original equipment manufacturer, sending a nonce assigned to a second part of the verification authority of the identification key provided by the original equipment manufacturer from the authentication authority via the charging station to a control unit of the vehicle under a challenge-response protocol,and enabling the charging of the vehicle using the charging station if the vehicle's control unit returns the nonce correctly encrypted with the second part of the identification key stored in the vehicle's control unit to the authentication point. Advantages of the invention

[0009] One of the concepts of the present invention is to simplify the authentication and authorization process of an electric vehicle being charged at a charging station. In particular, the invention eliminates the need for certificates and costly and complex certificate management in the vehicle and charging station. Only low-maintenance components are required for the charging process, eliminating the need for a Pool&Service (PuS). The interaction for the vehicle user when initiating a charging process is simple, intuitive, and convenient.

[0010] According to some embodiments of the charging system, the charging station can be configured to read the first part of the identification key from the control unit of the vehicle being charged in encrypted form and transmit it in encrypted form to the authentication point. This increases the security of the authentication process against eavesdropping attempts by unauthorized third parties.

[0011] According to various embodiments of the charging system, the vehicle's control unit can be configured to encrypt the received nonce with the second part of the identification key using a cryptological or cryptographic hash function. This also increases the security of the authentication process against eavesdropping attempts by unauthorized third parties.

[0012] According to several embodiments of the charging system, the charging station can further be configured to transmit a user-related identification code of the user of the vehicle to be charged at the charging station to the authentication point. The authentication point can further be configured to bill the charging process to the user's account if the transmitted user-related identification code matches a verification instance of the transmitted user-related identification code stored in the authentication point. This allows the authentication of the vehicle to be separated from the authentication and authorization of a user, particularly when vehicles can be assigned to different users, such as in a company vehicle fleet.

[0013] According to some embodiments of the charging system, the user-specific identification code can be created by the original equipment manufacturer and uniquely assigned to the unique alphanumeric identification key. This advantageously enables a link between a vehicle and a user, secured and certified by a trusted party such as an original equipment manufacturer.

[0014] According to several embodiments of the method, the first part of the identification key can be read in encrypted form from the control unit of the vehicle to be charged and transmitted in encrypted form to the authentication center. This increases the security of the authentication process against eavesdropping attempts by unauthorized third parties.

[0015] According to a number of embodiments of the method, the method may further comprise the steps of transmitting a user-related identification code of the user of the vehicle to be charged at the charging station to the authentication point, and billing the charging process to the user's account if the transmitted user-related identification code matches a verification instance of the transmitted user-related identification code stored in the authentication point. This allows the authentication of the vehicle to be separated from the authentication and authorization of a user, particularly when vehicles can be assigned to different users, such as in a company vehicle fleet.

[0016] According to various embodiments of the method, the user-related identification code can be created by the original equipment manufacturer and uniquely assigned to the unique alphanumeric identification key. This advantageously enables a link between a vehicle and a user, secured and certified by a trusted party such as an original equipment manufacturer.

[0017] According to certain embodiments of the method, the received nonce can be encrypted by the vehicle's control unit with the second part of the identification key using a cryptological or cryptographic hash function. This also increases the security of the authentication process against eavesdropping attempts by unauthorized third parties.

[0018] The above embodiments and further developments can be combined with one another as desired, where appropriate. Further embodiments, further developments, and implementations of the invention also include combinations of features of the invention not explicitly mentioned above or described below with respect to the exemplary embodiments. In particular, those skilled in the art will also add individual aspects as improvements or additions to the respective basic forms of the invention. Short description of the drawings

[0019] Further features and advantages of the invention are explained below with reference to the figures. These show: Fig. 1: a schematic representation of an exemplary charging system for electrical energy storage devices of electrically powered vehicles; Fig. 2: a flowchart of a charging method for an electrical energy storage device of an electrically powered vehicle according to an embodiment; and Fig. 3: a sequence diagram for the message exchange in a loading process according to Fig. 2 between components of the charging system according to Fig. 1. Description of embodiments

[0020] Fig. 1 shows a schematic, simplified representation of an exemplary charging system 1 for electrical energy storage devices of electrically powered vehicles. Shown in simplified form are a charging station 2 of the charging system 1 and a vehicle 3 to be charged at the charging system 1. The vehicle 3 has an electrical energy storage device 7, which serves to supply an electric drive motor (not shown here) of the vehicle 3 with energy as needed and, in particular, to absorb the electrical energy generated by the drive motor during generator operation of the drive motor. The electrical energy storage device 7 can, for example, be the traction battery of a fully or at least partially electrically powered vehicle 3.

[0021] The charging station 2 is connected to a local energy network 4 and has a control unit 5 that establishes an electrical connection between the vehicle 3 and the energy network 4 to carry out a charging process. To charge the electrical energy storage device 7, electrical energy can be drawn from the local energy network 4. For this purpose, the vehicle 3 has a charging port 8 that can be connected to a charging port 9 of the charging station 2. For example, the charging port 8 is designed as a charging plug and the charging port 9 as a charging socket, wherein the charging plug can be inserted into the charging socket and thus electrically contacted. The charging ports 8 and 9 together form a charging interface 10 between the vehicle 3 and the charging station 2.

[0022] The vehicle 3 has its own control unit 11, which, for example, controls / regulates the internal energy distribution. In particular, the control unit 11 is designed to connect the energy storage device 7 to the charging port 8 in order to carry out a charging process. An electrical (DC) voltage applied to the charging port 8 by the local energy grid 4 can be provided to the electrical energy storage device 7, thereby charging the electrical energy storage device 7.

[0023] The control unit 11 is also responsible, in particular, for the authentication of the vehicle 3 to infrastructure components of the charging system 1. For this purpose, an original equipment manufacturer (OEM) 20 assigns uniquely assignable, alphanumeric, two-part identification keys to vehicles 3, the users 40 of these vehicles 3, and authentication points 30 of mobility infrastructure operators (MOs) involved in the charging system 1. This creation of identification keys already occurs during a production or delivery stage of electrically powered vehicles 3. A multitude of different individual identification keys 21a, 21b, ..., 21n can be stored in a database 22 of the original equipment manufacturer 20.In the authentication point 30, verification instances of uniquely distinguishable identification keys assigned to a plurality of different vehicles 2 can be stored in a key database 32.

[0024] The charging station 2 reads a first part of the unique alphanumeric identification key 21b assigned by the original equipment manufacturer 20 from the control unit 11 of the vehicle 3 to be charged at the charging station 2 and transmits the read first part to the authentication point 30. The reading and / or transmission can be carried out in encrypted form. For example, the vehicle's control unit 11 can transmit an encrypted form of the first part of the identification key 21b to the charging control unit 5 of the charging station 2, which then transmits this encrypted form to the authentication point 30. Alternatively or additionally, the charging control unit 5 of the charging station 2 can encrypt or re-encrypt the unencrypted or encrypted first part of the identification key 21b using a key function specific to the charging station 2.

[0025] The authentication point 30 compares the transmitted first part of the identification key 21b with a verification instance 34 of the identification key 21b provided to the authentication point 30 by the original equipment manufacturer 20. This allows the authentication point 30 to identify the vehicle 3 to be charged at the charging station 2. The authentication point 30 can then create a nonce associated with a second part of the verification instance 34 of the identification key 21b provided by the original equipment manufacturer 20 and send it as a challenge to the control unit 11 of the vehicle 3 via the charging station 2 using a challenge-response protocol.

[0026] The control unit 11 of the vehicle 3 encrypts the nonce with the second part of the identification key 21b stored in the control unit 11 of the vehicle 3, for example, using a cryptological or cryptographic hash function, and sends it back to the authentication point 30 as a response using the challenge-response protocol. The authentication point 30 uses its stored verification instance 34 of the identification key to verify whether the encryption was performed correctly. If successful, it can authenticate the vehicle 3 and authorize or authorize a charging process by the charging station 2.

[0027] In addition, a user 40 can transmit a user-related identification code of the user 40 to the authentication point 30 via the charging station 2, so that the authentication point 30 is able to bill the charging process to the account of the user 40 if the transmitted user-related identification code matches a verification instance 35 of the transmitted user-related identification code stored in the authentication point 30. This user-related identification code can be created, for example, by the original equipment manufacturer 20 and uniquely assigned to the unique alphanumeric identification key 21b.

[0028] Fig. 2 shows a flow diagram of a charging method M for an electrical energy storage device of an electrically powered vehicle, such as the energy storage device 7 of the vehicle 3 in Fig. 1. In particular, the charging method M can be used in connection with the Fig. 3 described charging system 1. The charging method M comprises, in a first step M1, reading out a first part of a unique alphanumeric identification key of the vehicle 3 to be charged at a charging station 2, said key being assigned by an original equipment manufacturer 20 of the electrically powered vehicle 3, by a charging station control unit 5 of the charging station 2. The reading out can, for example, take place automatically when a charging plug of the vehicle 3 is plugged into a charging socket of the charging station 2. This read out first part can be transmitted to an authentication point 30 in a second step M2. The reading out and transmission of the first part of the identification key can take place in encrypted form by the control unit 11 of the vehicle 3 performing appropriate encryption prior to reading out, for example using a cryptological hash function.The authentication point 30 can, for example, be a server of a mobility infrastructure operator (“mobility operator”, MO) that operates a number of charging stations 2.

[0029] The transmitted first part of the identification key is compared in a step M3 with a verification instance 34 of the identification key provided to the authentication point 30 by the original equipment manufacturer 20. In particular, a plurality of verification instances of uniquely distinguishable identification keys assigned to different vehicles 2 can be stored in a key database 32 in the authentication point 30. If the comparison of the first part of the identification key was successful, the authentication point 30 uses the second part of the verification instance 34 of the identification key provided by the original equipment manufacturer 30 to send a nonce assigned to this second part via the charging station 2 to a control unit 11 of the vehicle 3 using a challenge-response protocol in a fourth step M4.

[0030] The control unit 11 of the vehicle 3 encrypts the sent nonce with the second part of the identification key stored in the control unit 11 of the vehicle 3 and returns the encrypted nonce as a response in the challenge-response protocol to the authentication point 30. The authentication point 30 then checks whether the nonce has been returned correctly encrypted and, if so, authorizes a charging process of the vehicle 3 using the charging station 2 in a fifth step M5.

[0031] Optionally, in a step M6, a user-related identification code of the user 40 of the vehicle 3 to be charged at the charging station 2 can be transmitted to the authentication point 30. The authentication point 30 checks whether the transmitted user-related identification code matches a verification instance 35 of the transmitted user-related identification code stored in the authentication point 30, and in a further optional step M7, bills the charging process to the account of the identified user 40 at the MO assigned to the authentication point 30. The user-related identification code can also have been created by the original equipment manufacturer 20 and uniquely assigned to the unique alphanumeric identification key of the vehicle 3.

[0032] Fig. 3 shows an exemplary sequence diagram for the message exchange in a loading process M according to Fig. 2 between the respective components of the charging system 1 according to Fig. 1. In an upstream stage S1, an original equipment manufacturer (OEM) distributes 20 uniquely assignable, alphanumeric, two-part identification keys to vehicles 3, the users 40 of these vehicles 3, and authentication points 30 of MOs participating in the charging system 1. This creation of identification keys already takes place during a production or delivery stage of electrically powered vehicles 3. A plurality of different individual identification keys 21a, 21b, ..., 21n can be stored in a database 22 of the original equipment manufacturer 20.

[0033] If a vehicle 3 is to be charged at a charging station 2, the control unit 11 of the vehicle 3 transmits a first part of the respective identification key, preferably in encrypted form, to a charging control unit 5 of the charging station 2 in a charging request S2. This charging request S2 is forwarded by the charging control unit 5 of the charging station 2 to an assigned authentication point 30 of the respective MO of the charging station 2 (stage S3). The authentication point 30 identifies the respective vehicle 3 by comparing the received first part of the respective identification key with the identification key received from the original equipment manufacturer 20 and stored in the key database 32 of the authentication point 30. In the example of the Fig. 1, the identification key 21b matches the vehicle 3 shown and in the key database 32 of the authentication point 30, the verification instance 34 is assigned to the identification key 21b.

[0034] Upon transmission S3 of the charging request S2, the authentication point 30 initiates a challenge-response process in which the authentication point 30 sends a nonce associated with a second part of the identification key via the charging station 2 as a challenge S4a to the control unit 11 of the vehicle 3. The control unit 11 of the vehicle 3 encrypts the nonce with the second part of the identification key stored in the control unit 11 and sends the encrypted nonce back to the authentication point 30 as a response S4b. The response S4b is verified by the authentication point 30, and if correct, the charging station is granted authorization S5 for the charging process.

[0035] For additional authorization of a user 40, the user 40 can send an authorization request S6 with a user-related identification code to the charging station 2, which then transmits the authorization request S6 to the authentication authority 30 (stage S7a). The authentication authority 30 compares the transmitted user-related identification code with a corresponding verification authority 35 in its key database 32 and returns a billing authorization S7b to the charging station 2, so that the charging process can be carried out using the account of the identified and authorized user 40 at the respective MO.

[0036] In summary, the present invention relates to a concept for simplified and ubiquitously deployable authentication and authorization of an electrically powered vehicle to be charged at a charging station of a charging system. To this end, it is proposed that an original equipment manufacturer of the vehicle install a two-part, unique alphanumeric identification key in the vehicle's control unit, transmit a first part of the identification key in a charging process request via the charging station to an authentication authority, and have the authentication authority compare the transmitted first part with a verification authority of the identification key provided to the authentication authority by the original equipment manufacturer.The second part of the identification key is used for a challenge-response procedure in which the authentication authority transmits a nonce assigned to a verification instance of the second part to the vehicle's control unit, which encrypts the nonce with the second part of the identification key stored in the vehicle's control unit and sends it back to the authentication authority for successful authentication and authorization of the charging process. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 4 072 180 A1

[0005] Zitierte Nicht-Patentliteratur

[0000] Shuaib, E. Barka, J. A. Abdella and F. Sallabi, „Secure charging and payment protocol (SCPP) for roaming plug-in electric vehicles,“ 2017 4th International Conference on Control, Decision and Information Technologies (CoDIT

[0005]

Claims

[1] Charging system (1) for an electrical energy storage device (7) of an electrically powered vehicle (3), comprising: a charging station (2) with a charging station control unit (5); and an authentication authority (30), wherein the charging station (2) is designed to read out a first part of a unique alphanumeric identification key (21b) of the vehicle (3) to be charged at the charging station (2) and to transmit it to the authentication point (30), and wherein the authentication point (30) is designed to compare the transmitted first part of the identification key (21b) with a verification instance (34) of the identification key (21b) provided to the authentication point (30) by the original equipment manufacturer (20), to send a nonce associated with a second part of the verification instance (34) of the identification key (21b) provided by the original equipment manufacturer (20) to a control unit (11) of the vehicle (3) via the charging station (2) using a challenge-response protocol, and to enable the charging station (2) to charge the vehicle (3) if the control unit (11) of the vehicle (3) returns the nonce with the second part of the identification key (21b) stored in the control unit (11) of the vehicle (3) to the authentication point (30) in a correctly encrypted manner. [2] Charging system (1) according to claim 1, wherein the charging station (2) is designed to read the first part of the identification key (21b) from the control unit (11) of the vehicle (3) to be charged in encrypted form and to transmit it in encrypted form to the authentication point (30). [3] Charging system (1) according to claim 1 or 2, wherein the control unit (11) of the vehicle (3) is designed to encrypt the received nonce with the second part of the identification key (21b) via a cryptological hash function. [4] Charging system (1) according to one of claims 1 to 3, wherein the charging station (2) is further designed to transmit a user-related identification code of the user of the vehicle (3) to be charged at the charging station (2) to the authentication point (30), and wherein the authentication point (30) is further designed to bill the charging process to the user's account if the transmitted user-related identification code matches a verification instance (35) of the transmitted user-related identification code stored in the authentication point (30). [5] Charging system (1) according to claim 4, wherein the user-related identification code has been created by the original equipment manufacturer (20) and has been uniquely assigned to the unique alphanumeric identification key (21b). [6] Method (M) for charging an electrical energy storage device (7) of an electrically powered vehicle (2), comprising the steps: Reading (M1) a first part of a unique alphanumeric identification key (21b) of the vehicle (3) to be charged at a charging station (2), assigned by an original equipment manufacturer (20) of the electrically operated vehicle (3), by a charging station control unit (5) of the charging station (2); Transmitting (M2) the read-out first part of the identification key (21b) to an authentication point (30); comparing (M3) the transmitted first part of the identification key (21b) with a verification instance (34) of the identification key (21b) provided to the authentication point (30) by the original equipment manufacturer (20); Sending (M4) a nonce associated with a second part of the verification instance (34) of the identification key (21b) provided by the original equipment manufacturer (20) from the authentication point (30) via the charging station (2) to a control unit (11) of the vehicle (3) under a challenge-response protocol; and Enabling (M5) the charging of the vehicle (3) by means of the charging station (2) if the control unit (11) of the vehicle (3) returns the nonce with the second part of the identification key (21b) stored in the control unit (11) of the vehicle (3) correctly encrypted to the authentication point (30). [7] Method (M) according to claim 6, wherein the first part of the identification key (21b) is read out in encrypted form from the control unit (11) of the vehicle (3) to be charged and is transmitted in encrypted form to the authentication point (30). [8] Method (M) according to one of claims 6 and 7, further comprising the steps: Transmitting (M6) a user-related identification code of the user of the vehicle (3) to be charged at the charging station (2) to the authentication point (30); and Billing (M7) the charging process with the user's account if the transmitted user-related identification code matches a verification instance (35) of the transmitted user-related identification code stored in the authentication point (30). [9] Method (M) according to claim 8, wherein the user-related identification code has been created by the original equipment manufacturer (20) and has been uniquely assigned to the unique alphanumeric identification key (21b). [10] Method (M) according to one of claims 6 to 9, wherein the received nonce is encrypted by the control unit (11) of the vehicle (3) with the second part of the identification key (21b) via a cryptological hash function.

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