1.Summary

1.1 Tianjin yidingfeng integrated BMS (28 series integrated BMS) system uses NXP analog front end for data acquisition and transmission of battery cells. The integrated BMS can be responsible for the sampling and equalization control of cell temperature and voltage, as well as collecting the total voltage, total current, insulation, environment / cooling medium temperature, charging interface temperature, hvil, charging circuit status, etc; Control the contactor, thermal management system and charging and discharging point control of battery system; The parameters of SOC, SOH, sof, actual capacity and internal resistance are calculated; Diagnose the fault of battery system and deal with it.

1.2 in order to ensure the high safety of the battery system, Tianjin yidingfeng BMS adopts the following high safety design:

(1) Adopt the requirements of automobile level and development process.

(2) Perfect fault diagnosis and protection mechanism, including: adhesion detection, insulation, over voltage, undervoltage, over current, short circuit (internal and external), over temperature, etc.

(3) Periodically wake up battery safety monitoring, monitor the status of power battery system under shutdown state, and prevent dangerous events in the case of battery system placement.

(4) Under the condition of BMS dormancy, abnormal state of the core can still be monitored. Wake up the main MCU immediately after the core is found abnormal, so as to timely report data and corresponding protection measures.

(5) In order to ensure the effectiveness and accuracy of the algorithm, the software algorithm not only includes the basic time accumulation and eigenvalue correction, but also the advanced SOC algorithm of internal resistance, temperature estimation of the core, real-time calculation of OCV and adaptive filtering; The advanced algorithms such as real-time correction of battery capacity ensure the accuracy of SOC and SOH of the battery, and accurately estimate the allowable charge and discharge power of the battery, and extend the service life of the battery.

2. Basic Functions

2.1 safety protection strategies: over charging protection, over discharge protection, high temperature protection, low temperature protection, current over-current protection and other 100 fault protection strategies.

2.2 accurate battery energy management: yidingfeng battery management system adopts model design, accurately estimates the battery SOC based on the second-order equivalent circuit, ensures that the SOC is maintained in a reasonable range, prevents damage to the battery due to overcharge or overdischarge, and accurately calculates the amount of energy or the state of charge of the energy storage battery.

2.3 intelligent battery charging management: Based on the battery equivalent circuit model charge algorithm management, accurately estimate the state of the battery in the future 10s, adjust the charging current ahead of time, prevent the battery from being damaged by overcharge, effectively extend the battery life, and ensure the charging efficiency.

2.4 reliable full condition balancing scheme: the full condition balancing scheme based on the battery equivalent circuit can balance the battery pack in the full condition and full period of vehicle use, greatly improving the battery balancing efficiency, effectively ensuring the consistency of the unit, and extending the battery life and driving range.

2.5 safe thermal management: thermal safety management, cooling control, heating and insulation control. BMS ensures the temperature difference of the battery cell, keeps the consistency of the cell, and extends the service life of the battery.

2.6 advanced contactor control strategy: it can not rely on the feedback signal of the contactor, but only rely on the logic to judge the contactor adhesion, unable to close and other faults.

2.7 battery internal resistance, internal temperature and OCV real-time calculation, timely predict the battery according to the battery state, adjust the charge and discharge current in advance, calibrate the SOC in time, and accurately estimate the SOH of the battery.

2.8 perfect fault protection strategy: accurately judge the possible faults of the battery to ensure the normal driving of the vehicle while meeting the user experience.

2.9 data monitoring and calibration based on CCP protocol.

2.10 insulation test meeting the requirements of national standard.

2.11 software development based on AUTOSAR architecture ensures the reliability and portability of the program and facilitates the upgrade of BMS development.

3.Technical Parameter