BMS Safety Design: Best Practices for Preventing Battery Hazards
1. Voltage isolation and strong EMC anti-interference capabilities are prerequisites for BMS collection circuits. Special integrated circuits are generally not advised because they cannot achieve fault diagnosis, accuracy, passive equalization, or high-precision AD conversion. Examples of these circuits include optocoupler relay + external AD, data processing, passive equalization, drop monitoring, and high anti-interference ability. It is hard to guarantee, and it is not very resistant to interference.
2. It is advised that the voltage monitoring point and temperature monitoring point be set to 1:1 and +2 (monitor module connector temperature), respectively, to guarantee that the temperature of each cell can be observed. In order to reduce the temperature monitoring delay and increase accuracy, temperature monitoring points must also be installed on the battery pole. Incorporate temperature monitoring at critical locations that are prone to overheating, like circuit breakers, relays, and power bus connection points.
3. Battery system safety will be directly impacted by SOS, and BMS ought to be able to assess the state of battery safety. It is impossible to determine the actual temperature inside the battery because temperature monitoring is either not done at this time or is limited to measuring the temperature of the confluence. As a result, there is a serious hidden risk to the battery's safe operation when the heat inside the battery gets out of control and the rapidly rising temperature is not noticed in time. Likewise, in the event that both the battery temperature and internal pressure rise too high, the safety valve will open. However, since safety valve monitoring is currently lacking, preventive actions such as shutting off the circuit, halting operation, initiating local cooling, and initiating firefighting cannot be taken in a timely manner. As a result, the two points mentioned above will eventually lead to breakthroughs in BMS security design.
Energy Storage BMS Development Trend
As monomer battery capacity increases, battery imbalance becomes more severe.
Passive equalization technology is no longer sufficient to balance battery systems and extend battery life.
Active equalization technology is an inevitable trend in the development of energy storage BMS.
Active equalization can extend battery life by 20%, which has high economic benefits.
Development Trend of Energy Storage BMS Battery Sensing Technology
The development of battery sensors and wireless BMS has become a priority due to the swift advancement of this technology. Future research and discussion on BMS are critically needed.
problems with the technology of the current battery management system. There are obstacles in the way of technological advancement for the current battery management system:
1. There are two unsolvable issues because the voltage and temperature recorded by the current battery management system are the external parameters of the cell.
(a) Because the battery's internal temperature cannot be measured, it is impossible to accurately determine how hot it gets inside. As a result, in the event of a small internal short circuit or thermal runaway cell, prompt safety warning and protection are not possible. This is a really big issue. The temperature inside the battery can be used to predict the thermal runaway of the battery in advance, preventing many combustion and explosion accidents that have happened in electric cars and energy storage power plants. However, the system has experienced thermal runaway precisely as a result of the temperature gradient's influence and the delay in temperature sampling. It's too late to issue warnings and safeguards. This problem, which must be resolved immediately, is connected to the battery system's safety.
(b) It is impossible to precisely determine the true state of the battery, including its capacity, health, attenuation, safety status, etc., since the real temperature and other state parameters inside the battery cannot be obtained.
2. The current battery management system must gather wire harness data to gather parameters like voltage, temperature, and other data. Numerous failure hazards, including poor contact, will arise because of the numerous geranium beams, sampling points, and connectors attached to the wire harness. In addition, it will result in production issues, insulation deterioration, and power leaks brought on by wire harness aging, damage, or extrusion. The system's potential safety risk.
3. Since wire harness installation is typically done by hand, production and installation costs will inevitably rise.
4. Ineffective cell detection in the absence of installation and operation; damage to the battery; and thermal runaway safety.
Energy storage BMS development is moving in the direction of active equalization technology. This is because active equalization, particularly for large-capacity battery systems, can more successfully balance battery systems and increase battery life. Because active equalization technology can increase battery life by up to 20%, it offers significant economic benefits.
Since batteries account for a large portion of the cost of energy storage systems, this represents substantial savings for users of energy storage. Active equalization technology is where energy storage BMS development is trending. This trend is advantageous since it will result in energy storage systems that are more dependable and efficient.