Energy storage battery and power lithium battery-Lithium - Ion Battery Equipment

Differences between energy storage battery BMS and power lithium battery BMS -Lithium - Ion Battery Equipment

1 Application scenario of large-scale energy storage system

In order to stabilize the fluctuation of output power, more and more new energy power plants, wind power plants or solar power plants are equipped with energy storage systems.

With the reform of the electric power system, independent energy storage power stations have gradually entered people's vision, and independent energy storage power stations that make a living by reselling electricity have gradually emerged.(Lithium - Ion Battery Equipment)

Microgrid, a small power supply and distribution network with distributed generation, power load, energy storage system and grid management system. To ensure the continuity and stability of load power consumption, each microgrid will be equipped with an energy storage system.

Indoor energy storage power station

2 Differences between energy storage battery management system (ESBMS) and power battery management system (BMS)

The energy storage battery management system is very similar to the power battery management system. However, when the power battery system is on the high-speed electric vehicle, there are higher requirements for the power response speed and power characteristics of the battery, the accuracy of SOC estimation, and the number of state parameter calculations.

The scale of energy storage system is very large, and the difference between centralized battery management system and energy storage battery management system is obvious. Here, we only take the power battery distributed battery management system for comparison.

2.1 The location of the battery and its management system in their respective systems is different.

In the energy storage system, the energy storage battery only interacts with the energy storage converter on high voltage, and the converter takes power from the AC power grid to charge the battery pack; Or the battery pack supplies power to the converter, and the electrical energy is converted into AC through the converter and sent to the AC power grid.

Communication of the energy storage system. The battery management system mainly has information interaction with the converter and the scheduling system of the energy storage power station. 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 scheduling system PCS of the energy storage plant. As shown in the figure below.

Basic topology of energy storage system

The BMS of electric vehicle has energy exchange relationship with motor and charger on high voltage; In terms of communication, there is information interaction with the charger in the charging process, and the most detailed information interaction with the vehicle controller in all application processes. As shown in the figure below.

Electrical topology of electric vehicle

2.2 Different hardware logical structures

The hardware of the energy storage management system generally adopts a two-layer or three-layer model, and the large-scale ones prefer a three-layer management system, as shown in the figure below.

Block diagram of three-layer energy storage battery management system

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

Block Diagram of Distributed EV Battery Management System

In terms of functions, the first and second layer modules of the energy storage battery management system are basically equivalent to the first layer acquisition module and the second layer master control module of the power battery. The third layer of the energy storage battery management system is an additional layer on this basis to cope with the huge scale of the energy storage battery.

Take a less appropriate analogy. The best number of subordinates for a manager is 7. If the department has been expanding and 49 people have emerged, 7 people will have to choose a team leader and appoint a manager to manage the 7 team leaders. Beyond personal ability, management is prone to confusion.

Mapping to the energy storage battery management system, this management capability is the computing power of the chip and the complexity of the software program.

2.3 Differences in communication protocols

The internal communication between the energy storage battery management system and the internal communication is basically based on CAN protocol, but the external communication mainly refers to the energy storage power station dispatching system PCS, which often uses the Internet protocol format TCP/IP protocol.



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