QC/T 842-2010 English PDF (QCT842-2010)
QC/T 842-2010 English PDF (QCT842-2010)
See Chinese contents: QC/T 842-2010
QC/T 842-2010: Communication protocols between battery management system and off-board charger for electric vehicles
AUTOMOTIVE INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
Communication Protocols between Battery
Management System and Off-board Charger for
ISSUED ON. NOVEMBER 22, 2010
IMPLEMENTED ON. MARCH 1, 2011
Issued by. Ministry of Industry and Information Technology of the
People's Republic of China
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms and Definitions ... 5
4 Physical Layer Interface ... 6
5 Data Link Layer ... 6
6 Charging Process ... 8
Annex A (Normative) Format and Content of Application Layer Messages
Annex B (Informative) Charging Flow Charts ... 25
The data frame format of this Standard is specified in CAN Bus Technical Specifications 2.0 issued in September, 1991.
Annex A of this Standard is normative; Annex B is informative.
This Standard was proposed by and shall be under the jurisdiction of the National Technical Committee of Auto Standardization.
The drafting organizations of this Standard. Tianjin Qingyuan Electric Vehicle Co., Ltd., China Automotive Technology and Research Center, Shenzhen BYD Co., Ltd., Chery Automobile Co., Ltd., Beijing Institute of Technology, Beijing Jiaotong University, Institute of Electrical Engineering Chinese Academy of Science and China Electronics Technology Group Corporation No. 10 Research Institute.
The main drafters of this Standard. Zhao Chuning, Zhou Nenghui, Meng Xiangfeng, Zhang Guangxiu, Wang Zhenpo, Jiang Jiuchun, Zhang Jianhua, Xiao Chengwei, Wang Lifang, Li Lei, Fang Yunzhou and Wang Fang.
Communication Protocols between Battery
Management System and off-board Charger for
This Standard specifies communication protocols between battery management system (hereinafter referred to as BMS) and off-board charger (hereinafter referred to as charger) for electric vehicles.
This Standard applies to off-board charging for electric vehicles.
CAN identifier of this Standard is 29 bits, and communication baud rate is 250 kbps, but this Standard is not limited to 29-bit identifier and 250 kbps communication baud rate. If other formats are used, their CAN identifier shall be made by reference to this Standard.
Data transmission of this Standard is by the format of low bits transmitted first. Negative current value represents charging; positive current value represents discharging.
2 Normative References
The provisions in the following documents become part of this Part through reference in this Standard. For dated documents, the subsequent amendments (excluding corrigenda) or revisions do not apply to this Standard. However, all parties who enter into agreement based on this Standard are encouraged to study whether the latest versions of these documents are applicable. For undated documents, the latest versions apply to this Standard.
ISO 11898-1.2006, Road Vehicles – Controller Area Network (CAN) – Part 1. Data Link Layer and Physical Signalling
SAE J1939-11.2006, Recommended Practice for a Serial Control and
Communications Vehicle Network – Part 11. Physical Layer, 250K bits/s, Twisted Shielded Pair
One or more CAN data frames with the same parameter group number
4 Physical Layer Interface
4.1 The Physical layer realizes the electric connection in the network between BMS and charger
4.2 A CAN interface independent to the power assembly control system is preferred for the communications between BMS and charger.
4.3 The Physical layer adopting this Standard shall meet the specifications of the international standards ISO 11898-1 and SAE J1939-11.
5 Data Link Layer
Data link layer provides reliable data transmission between physical connections. 5.2 Frame format
As shown in Figure 1, the CAN extended data frame is divided into different bit fields, where the arbitration field which has a 29-bit identifier, including an11-bit basic identifier and an 18-bit identifier extension. The CAN data frame format of this Standard is referred to SAE J1939-21; and the 29-bit identifier of the arbitration field is further defined.
5.3 Protocol data unit
The CAN data frame includes a single protocol data unit (PDU), as shown in Figure 2. The protocol data unit consists of seven parts, namely priority (P), reserved bits (R), data page (DP), PDU format (PF), PDU specific (PS), source address (SA) and data field.
The description of all parts in the protocol data unit is as follows.
5.3.1 Priority (P)
or charger fails to receive each other’s message within the specified period of time, it is determined that it is a time-out, and the time-out time is always 5s, unless otherwise specified; and in the event of a time-out, the BMS or charger sends the error message and enters the error handling state. See Annex A for the formats and contents of messages; and see Annex B for the overview flow charts and flow charts of all phases of the charging process.
6.2 Handshake phase
After the physical connection between BMS and charger is completed and electrified, and that the manual setting of CAN identifier format and communication baud rate is completed, the BMS and charger enter the handshake phase. During the handshake phase, the BMS first test whether the low-voltage auxiliary power supply is normal; if it is not normal, the BMS sends error message to the charger, and the charge should turn off the output of low-voltage power supply; if the low-voltage power supply is normal, both sides shall do handshake during the phase, and determine the battery information (e.g. battery type and manufacturing date of battery pack) and the relevant information of the charger (e.g. charger number and charging plug number). 6.3 Configuration phase
After the handshake phase, the BMS and charger enter the configuration phase. During the phase, the charger sends the message of its maximum output capacity to the BMS; then the BMS judges whether charging can be done in accordance with the maximum output capacity of the charger.
6.4 Charging phase
After the configuration phase, the BMS and charger enter the charging phase. During the whole charging phase, the BMS controls the whole charging process by sending in real time the battery charging level requirements to the charger. The charger regulates the charging voltage and charging current to ensure the charging process is normal based on the battery charging level requirements; in addition, the BMS and charger also send each other their own charging states, and when the BMS sends a message for the first time during the charging phase, it gives priority to the message of the battery charging state.
The BMS judges whether to terminate charging, in accordance with whether the charging process is normal or not, whether the battery state meets the charging termination conditions set by the BMS or not and whether the BMS receives the charging termination message from the charger; and the charger judges whether to terminate charging, in accordance with whether the charging process is normal or not, whether the charging parameters set by human are met or not and whether the charging termination message from the BMS is received or not.
6.5 Charging termination phase
description Byte7 Byte6 Byte5 Byte4 Byte3 Byte2 Byte1 Byte0
D20 to D21 –
Message purpose. to provide the charger identification information to the BMS. Sending section. the handshake phase. After the physical connection between BMS and charger is completed and electrified, and that the manual setting of CAN identifier format and communication baud rate is completed, the charger sends messages to the BMS once every other 250 ms.
Sender. the charger.
a) Charger number.
data length. 1 byte; format. 1/ bit, 0 offset; data scope. 0 to 255;
b) Charging plug number.
data length. 1 byte; format. 1/bit, 0 offset; data scope. 0 to 255.
A.1.3 Battery information messages
Message code Message description Priority Data byte Refresh rate 29-bit identifier BIM Battery identification message 6 8 250 ms 0x18E5E5F4
Message code Message description Byte7 Byte6 Byte5 Byte4 Byte3 Byte2 Byte1 Byte0 BIM Battery information message Battery pack ID number Battery type Day Month Year Message purpose. to confirm the battery information.
Sending section. the handshake phase. the BMS sends messages to the charger once every other 250 ms until it receives the message of the maximum output capacity of the charger.
Sender. the BMS.
data length. 2 bytes; format. 0.1 V/bit, 0V offset; data scope. 0 to 800 V; b) Maximum charging voltage.
the maximum c...