Difference between power battery BMS and energy storage battery BMS

Difference between power battery BMS and energy Storage Battery BMS

1. Application scenarios of large-scale energy storage systems

For new energy power stations, wind power generation, or solar power stations, more and more power plants are beginning to deploy energy storage systems in order to stabilize output power fluctuations.

Independent energy storage power stations have gradually entered the field of vision with the reform of the power system, and independent energy storage power stations that rely on reselling electricity have gradually emerged.

Microgrid, the system contains a distributed power supply, electricity load, energy storage systems and a small power distribution network management system. In order to ensure the electrical continuity and stability of the load, each microgrid is equipped with an Energy Storage System.

2. Differences between ESBMS and BMS

The energy storage battery management system is very similar to the power battery management system. However, the power battery system is in a high-speed electric vehicle, and has higher requirements on the power response speed and power characteristics of the battery, the SOC estimation accuracy, and the number of calculations of the state parameters.

The energy storage system has a large scale. There is a significant difference between the centralized battery management system and the energy storage battery management system. Here, we only take the power battery distributed battery management system as a comparison.

2.1 The battery and its management system are different in their respective systems

In the energy storage system, the energy storage battery only interacts with the energy storage converter at high pressure, the converter takes power from the AC grid, and charges the battery pack; or the battery pack supplies power to the converter, and the power passes through the converter. Convert to AC to send to AC.

The communication of the energy storage system and the battery management system mainly interact with the converter and the storage power station scheduling system. On the one hand, the battery management system sends important status information to the converter to determine the high-voltage power interaction. On the other hand, the battery management system sends the most comprehensive monitoring information to the storage system PCS. As shown below.

Energy storage system basic topology

The BMS of an electric vehicle has an energy exchange relationship with a motor and a charger on high voltage; in terms of communication, there is information exchange with the charger during charging, and the entire vehicle controller has the most detailed information on the application process. Information exchange. As shown below.

Electric Vehicle Electrical Topology

2.2 The hardware logic structure is different

In energy storage management systems, the hardware generally adopts a two-tier or three-tier model, and the larger-scale one tends to a three-tier management system, as shown in the following figure.

Three-layer energy storage battery management system block diagram

The power battery management system has only one layer of centralized or two distributed, and basically there will be no three-tier situation. Small cars mainly use a layered centralized battery management system. The two-tier distributed power battery management system is shown in the figure below.

Distributed Electric Vehicle Battery Management System Block Diagram

From a functional standpoint, the first and second tiers of the energy storage battery management system are basically equivalent to the first tier acquisition module and the second tier main control module of the power battery. The third layer of the energy storage battery management system is an additional layer based on this to deal with the huge scale of energy storage batteries.

It is not a proper analogy to fight. The best number of subordinates of a manager is seven people. If this department has been expanding and there are 49 people, then only seven people should select a group leader, and then a manager will be appointed to manage the seven group leaders. Beyond individual capabilities, management is prone to confusion.

Mapping to energy storage battery management systems, this management capability is the chip's computing power and software program complexity.