BMS full life cycle testing solution

The battery management system (BMS) not only monitors battery voltage, current, temperature and other parameters in real time, but also takes into account leakage detection, thermal management, battery balancing management, alarm reminder, SOC calculation, SOH status report and other functions during battery charging and discharging, so that the battery is always in a safe and controllable charging and discharging process, which greatly improves the cycle life of the battery in actual use. Therefore, all BMS manufacturers attach great importance to the detection of BMS research and development, testing, production and other links.
Taking new energy vehicles as an example, according to authoritative reports, batteries account for more than one-third of all costs of electric vehicles. Breakthroughs in battery technology require a relatively long process, and BMS, as the nerve center of the battery pack, controls all the dynamics of the battery pack. Battery manufacturers or BMS manufacturers have invested heavily in the research of BMS, which is also a key factor in improving the battery pack's mileage and stability.

● The specific functions are as follows:

1.Real-time communication: During the working process of the battery, a series of battery-related parameters such as battery voltage, temperature, working current, battery power, etc. are monitored or calculated in real time.
2.Protection function: Determine the current state of the battery based on the reading of the battery working state and parameters to perform corresponding protection operations to prevent the battery from overcharging or over-discharging.
3.Voltage and temperature detection: The voltage and temperature values of a single battery cell are collected through the measurement sensor inside the BMS.
4.Charge and discharge management: The optimal charge or discharge curve of the battery (such as charging current, charging upper limit voltage value, discharge lower limit voltage value, etc.) is set according to the collected voltage and temperature through the charge and discharge strategy using different working states.
5.Balance management: According to the balance strategy, the battery power with poor consistency is pulled to the same level by transferring power (active balance) or directly releasing power through resistance (passive balance).
6.SOC calculation: The voltage method estimates the SOC based on the lithium battery SOC voltage-capacity model.

The NGI-BMS test system is built with NGI's self-developed test instruments. The equipment appearance, communication protocol, communication interface, etc. all adopt unified standards, and both scalability and maintainability are very high. The specific test system adopts the following architecture. For each function of BMS, targeted instruments are used for data simulation to test whether the BMS can work according to the requirements of the planned design. The system is mainly composed of high-precision battery simulator, temperature simulator, total voltage simulation unit, charge and discharge current simulation unit, temperature simulation unit, insulation resistance detection unit, signal and switch quantity detection unit, CAN communication unit, software control system, etc. The NGI-BMS test system provides BMS full life cycle solutions, BMS production line PCBA FCT test, BMS laboratory EOL function test, BMS aging test, which can be widely used in electric vehicle factories, battery module manufacturers, BMS manufacturers, energy storage system manufacturers, etc.

All test equipment in the NGI-BMS test system is independently developed by NGI, the overall architecture is modular, and the communication protocol, communication interface, etc. adopt unified standards to facilitate later expansion and maintenance. In addition, the system has high integration and wide application coverage, covering various software and hardware such as high-precision battery simulators, temperature simulators, total voltage simulation units, and charge and discharge current simulation units, which can effectively support various R&D and production testing needs of BMS. The system adopts an integrated design of software and hardware and is rich in functions. While ensuring the stable operation of the system, it can quickly meet the testing needs of various types of BMS projects. The system supports customization, and can quickly respond to and meet the personalized testing needs of customers.

As the core component of the NGI-BMS test system, the performance of the battery simulator directly affects the entire test system, and can also save the actual battery charging and discharging time cost and daily maintenance cost. The NGI series battery simulator has high precision, high integration, and multi-functional characteristics. The accuracy of the entire series of products is as high as one ten-thousandth, so that the voltage and current acquisition accuracy of the tested BMS equipment can be more accurately judged. A single device can integrate up to 24 power supply channels that support series connection, greatly reducing the size of the system. The entire series of products can be divided into two types according to their functions: active/passive balancing and passive balancing. The active/passive balancing (dual-quadrant) battery simulator supports bidirectional current flow and can be used as both a power source and a load. In addition, the NGI battery simulator also supports multiple functional features such as power mode, channel readback, charging mode, SOC test, SEQ editing function, real-time curve, etc., with one machine for multiple uses, streamlining related test equipment and test processes. The entire series of products have completed circuit optimization for different chips and can be adapted to various specifications of BMS chip testing.