GB/T 38775.2-2020Electric vehicle wireless power transfer—Part 2: Communication protocols between on-board charger and wireless power transfer device (English PDF)

3.1 Charging Spot Identification

Charging spot identification refers to the unique information used to identify charging spot.

3.2 Charging Spot Information

Charging spot information refers to charging spot identification and coil information of charging spot in the ground system.

3.3 Coil Information

Coil information refers to information constituted of coil role, identification, type, power and frequency information to represent the identity and parameters of coil.

3.4 Ground Facilities Information

Ground facilities information refers to information constituted of the software and hardware version information of charging spot information, communication service unit (CSU), power transmit controller (PTC) and power factor correction (PFC), the binding relationship between communication service unit (CSU) and power transmit controller (PTC),

3.5 Charging State

Charging state refers to the state of the electric vehicle after it is connected to the power transfer system. It includes two states. charged and uncharged.

3.6 Vehicle System Information

5.1 Overview

In structure, the wireless charging system is divided into off-board devices and on-board devices, between which, there is no direct physical connection. During the wireless charging process, the off-board devices and on-board devices shall exchange information through wireless communication, so as to implement the control and management of the charging process.

5.2 Functions of Communication Units

The functions of the various communication units are as follows. […]

5.3 Physical Layer Protocol

The communication physical layer of CI interface shall comply with the stipulations of IEEE Std 802.11TM.

5.4 Communication Interface

The wireless charging system has the following interfaces.

5.5 Relationships among CSU, PTC and PrC

Figure 2 is a diagram of the relationships among CSU, PTC and PrC. One CSU may control multiple PTCs, while one PTC can only be controlled by one CSU.

PTC may supply power to a specified PrC through a controllable switching element;

PTC may also simultaneously supply power to multiple PrCs by setting a controllable switching element. The control of the controllable switching element shall be performed by CSU.

5.6 Security

IVU and CSU shall check the integrity of device information, so as to prevent modification.

6.1 Overall Process of Charging

The normal charging process of the electric vehicle wireless charging system is shown Charging Spot 1 Charging Spot 2 Charging Spot m-1 Charging Spot m in Figure 3. The charging process of the vehicle-side and the ground-side devices has 4 states in total, which are respectively. communication unconnected, communication connected, standby and charging.

6.2 Charging Process of Case A Communication

6.2.1 IVU initiation

IVU initiation process is shown in Figure 4.IVU initiates registration with CSU. After IVU registers, it reports vehicle system information to CSU, then, CSU returns the preparation state information to IVU.

6.2.2 IVU's initiation of charging

The process of IVU's initiation of charging is shown in Figure 5. This process is used when IVU takes the initiative to initiate the charging process to CSU.

6.2.3 Charging normally stops

Under normal conditions, the process of IVU's triggering of stop charging is shown in Figure 6.

6.2.4 Charging abnormally stops

When CSU or IVU detects a fault, or, when PTC or PPC detects a fault, the process of stop charging is shown in Figure 7.

6.3 Charging Requirements of Case A Communication

6.3.1 Registration process IVU

registration process is shown in Figure 8. This process is used when IVU registers with CSU.

6.3.3 IVU charging spot identification reporting process

IVU charging spot identification reporting process is shown in Figure 10. This process is used to acquire charging spot identification information and report to CSU after a vehicle drives into a charging spot.

6.3.4 Information reporting and query

6.3.5 Charging state control process

6.3.6 Keep alive process

The keep alive process is shown in Figure 17. This process is used in keep alive between CSU and IVU during the charging process.

6.3.7 Message abnormality handling

6.4 Charging Process of Case B Communication

6.4.1 CSU initiation

The process of CSU initiation is shown in Figure 18. During this process, CSU registers to WCCMS. After CSU registers,

6.4.2 IVU initiation

The process of IVU initiation is shown in Figure 19.IVU registers to CSU. After IVU registers, it reports vehicle system information to CSU. Then, CSU reports vehicle information to WCCMS; CSU returns the preparation state to IVU.

6.4.3 IVU initiates charging

The process that normal IVU triggers start charging is shown in Figure 20. The charging process is as follows. […]

6.4.4 Charging normally stops

Under normal conditions, the process of IVU's triggering of stop charging is shown in Figure 21.CSU shall inform IVU and WCCMS of the charging state.

6.4.5 Charging abnormally stops

When a fault is detected, the process of stop charging shall be triggered, as it is shown in Figure 22.

6.5 Charging Requirements of Case B Communication

6.5.1 Registration process

6.5.5 Charging state control process

6.5.7 Message abnormality handling

6.5.7.1 Message abnormality handling during charging control process

Comply with 6.3.7.1.

6.5.7.2 Message abnormality handling during keep-alive process

Comply with 6.3.7.2.

7.1 Overview

This Chapter defines the message content of WC and CI interface. This Chapter does not specify the message content of WI interface. Interface message shall comply with TCP / IP Protocol.

7.2 Description of Message Header

The message header of wireless charging management communication protocol is shown in Table 1. Message attributes are shown in Table 2.

7.3 Message Type

The definition of message type is shown in Table 3.

7.4 Keep-alive Process Message

7.5 Registration Process Message

7.5.1 Registration request

Message purpose. used when CSU and IVU initiate registration request to WCCMS.

Triggering condition. after CSU is power on, initiate registration, or, after IVU acquires IP address, initiate registration.

7.5.3 Authentication request

Message purpose. used when WCCMS sends authentication request to CSU and IVU.

Triggering condition. WCCMS determines it is necessary to initiate authentication to CSU and IVU.

7.5.4 Authentication response

Message purpose. used when CSU and IVU send authentication response to WCCMS, indicate whether network authentication is successful or failed. When it is successful, the message shall include device calculation authentication code, which is used in network's authentication of the device.

7.7.2 Information reporting response

Message purpose. used when WCCMS returns information reporting request response to CSU, and IVU returns information reporting request response to CSU. Triggering condition. WCCMS receives CSU's information reporting request.

7.7.3 Information query request

Message purpose. used when WCCMS queries CSU about information, or IVU sends query information to CSU.

7.7.4 Information query response

Message purpose. used when CSU returns query information to WCCMS.

8.1 Overview

The parameters are encoded in TLV format, as it is shown in Table 27.

8.2 Parameter Type Value

The definition of parameter type is shown in Table 29.

8.3 Charging Spot Identification

It is a unique identification indicating the charging spot in the ground system. The type of encoding. OctetString.

8.4 Charging Spot Name

Charging spot name is a user-readable name that uniquely indicates the charging spot. The type of encoding. OctetString.

8.5 CSU User Identification

It uniquely identifies CSU user. The type of encoding. OctetString.

8.6 CSU Device Identification

It uniquely identifies CSU device. The type of encoding. OctetString.

8.7 IVU User Identification

It uniquely identifies IVU user. The type of encoding. OctetString.

8.8 IVU Device Identification

It uniquely identifies IVU device. The type of encoding. OctetString.

8.9 PTC Identification

It indicates PTC logical number, which uniquely identifies PTC in CSU. The type of encoding. OctetString.

8.10 PPC Identification

It is a unique identification indicating PPC in the vehicle system. The type of encoding.

8.11 PPC Address

It indicates PPC's physical address, which is used in PTC's communication with PPC. The type of encoding. OctetString.

8.17 Digital Signature

It is used in the registration request message, and locally generated by IVU or CSU.

IVU or CSU uses the hash algorithm to calculate the hash value of the device information for the hardware, firmware, software and configuration information; uses CSU and IVU private key to sign it. The type of encoding is. OctetString.

8.18 Random Number

It is used in the authentication request message, and randomly generated by WCCMS.

The random number of each authentication request being sent is different. The type of encoding is. OctetString.

8.19 Network Calculation Authentication Code

It is used in the authentication request message and generated by WCCMS in accordance with the random number and user private key. It is used in IVU and CSU's authentication of WCCMS. The type of encoding is. OctetString.

8.20 Device Calculation Authentication Code

It is used in the authentication response message and generated by IVU or CSU in accordance with the random number and user private key. It is used in WCCMS's authentication of IVU and CSU. The type of encoding is. OctetString.

8.23 PTC Information

It indicates the software and hardware information of PTC in the ground system. The type of encoding of PTC information is Grouped. See the specific information content

8.24 PFC Information

It indicates the software and hardware information of PFC in the ground system. The type of encoding of PFC information is Grouped. See the specific information contentbin Table 34.

8.25 Device's Software and Hardware Version Information

It indicates device's software and hardware version information. The type of encoding is.

8.26 Charging Spot Information

The type of encoding of charging spot information is. Grouped, which includes the information in Table 35.

8.27 Coil Information

The type of encoding of coil is OctetString. See the specific information in Table 36.

8.28 Vehicle System Information

It indicates PPC and IVU's device information in the vehicle system. The type of encoding is. Grouped. See the specific content in Table 40.

8.29 IVU Device Information

It indicates IVU device information in the vehicle system. See the specific content inbTable 41. […]