The BMS battery management system is simply the steward of the battery, playing an important role in ensuring safety, extending the service life and estimating the remaining power. It is an essential component of power and storage battery packs, increasing the life of the battery to a certain extent and reducing the losses caused by battery damage.
Energy storage battery management systems are very similar to power battery management systems. Most people do not know the difference between a power battery BMS management system and an energy storage battery BMS management system. Next, a brief introduction to the differences between power battery BMS management systems and energy storage battery BMS management systems.
1. The battery and its management system different positions in the respective systems
In an energy storage system, the energy storage battery only interacts with the high voltage energy storage converter, which takes power from the AC grid and charges the battery pack, or the battery pack supplies the converter and the electrical energy is converted to the AC grid via the converter.
The communication and battery management system of the energy storage system has information interaction mainly with the converter and the scheduling system of the energy storage plant. On the other hand, the battery management system sends important status information to the converter to determine the status of the high-voltage power interaction and, on the other hand, the battery management system sends the most comprehensive monitoring information to the PCS, the dispatching system of the energy storage plant.
The electric vehicle BMS has an energy exchange relationship with the electric motor and charger in terms of communication at high voltage, has information interaction with the charger during the charging process and has the most detailed information interaction with the vehicle controller during all applications.
2. The logical structure of the hardware is different
For energy storage management systems, the hardware is generally in two- or three-tier mode, with larger scale tending towards three-tier management systems. Power battery management systems have only one layer of centralised or two layers of distributed, and almost no three layers. Smaller vehicles mainly apply centralised battery management systems. Two-layer distributed power battery management system.
From a functional point of view, the first and second layer modules of the energy storage battery management system are basically equivalent to the first layer collection module and the second layer master control module of the power battery. The third layer of the storage battery management system is an additional layer on top of this, coping with the huge scale of the storage battery. Reflected in the energy storage battery management system, this management capability is the computational power of the chip and the complexity of the software program.
3. Different communication protocols
Energy storage battery management system and internal communication basically uses CAN protocol, but with external communication, external mainly refers to the energy storage power plant scheduling system PCS, mostly using the Internet protocol form TCP/IP protocol.
Power battery, the general environment of electric vehicles using the CAN protocol, only between the internal components of the battery pack using internal CAN, the battery pack and the whole vehicle between the use of the whole vehicle CAN to distinguish.
4.Ddifferent types of cores used in energy storage plants, the management system parameters vary considerably
Energy storage power stations, taking into account safety and economy, choose lithium batteries, mostly lithium iron phosphate, and more energy storage power stations use lead batteries and lead-carbon batteries. The mainstream battery type for electric vehicles is now lithium iron phosphate and ternary lithium batteries.
The different battery types have very different external characteristics and the battery models are not common at all. Battery management systems and core parameters must correspond one to the other. The detailed parameters are set differently for the same type of core produced by different manufacturers.
5. Different trends in threshold setting
Energy storage power stations, where space is more plentiful, can accommodate more batteries, but the remote location of some stations and the inconvenience of transport make it difficult to replace batteries on a large scale. The expectation of an energy storage power station is that the battery cells have a long life and do not fail. On this basis, the upper limit of their operating current is set relatively low to avoid electrical load work. The energy characteristics and power characteristics of the cells do not have to be particularly demanding. The main thing to look for is cost effectiveness.
Power cells are different. In a vehicle with limited space, a good battery is installed and the maximum of its capacity is desired. Therefore, the system parameters refer to the limit parameters of the battery, which are not good for the battery in such application conditions.
6. The two require different state parameters to be calculated
SOC is a state parameter that needs to be calculated by both. However, until today, there are no uniform requirements for energy storage systems. What state parameter calculation capability is required for energy storage battery management systems? In addition, the application environment for energy storage batteries is relatively spatially rich and environmentally stable, and small deviations are difficult to perceive in a large system. Therefore, the computational capability requirements for energy storage battery management systems are relatively lower than those for power battery management systems, and the corresponding single-string battery management costs are not as high as for power batteries.
7. Energy storage battery management systems Application of good passive balancing conditions
Energy storage power stations have a very urgent requirement for the equalisation capacity of the management system. Energy storage battery modules are relatively large in size, with multiple strings of batteries connected in series. Large individual voltage differences reduce the capacity of the whole box, and the more batteries in series, the more capacity they lose. From the point of view of economic efficiency, energy storage plants need to be adequately balanced.
In addition, passive balancing can be more effective with abundant space and good thermal conditions, so that larger balancing currents are used without fear of excessive temperature rise. Low-priced passive balancing can make a big difference in energy storage power plants.
Post time: Sep-22-2022