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, which has higher requirements for the battery's power response speed and power characteristics, SOC estimation accuracy, and the number of state parameter calculations.

1. Application scenarios of large-scale energy storage systems

In order to stabilize output power fluctuations in new energy power stations, wind power or solar power stations, more and more power plants are beginning to be equipped with energy storage systems.

Independent energy storage power stations, as the power system reform gradually enters people's field of vision, independent energy storage power stations that rely on reselling electricity for their livelihoods have gradually emerged.

Microgrid, a small power supply and distribution network that contains distributed power sources, electrical loads, energy storage systems, and grid management systems. In order to ensure the continuity and stability of the load, each microgrid will be equipped with an energy storage system.

2. The difference between energy storage battery management system (ES BMS) and power battery management system (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, which has higher requirements for the battery's power response speed and power characteristics, SOC estimation accuracy, and the number of state parameter calculations.

The scale of the energy storage system is extremely large, and the centralized battery management system is obviously different from the energy storage battery management system. Here, only the power battery distributed battery management system is compared with it.

2.1. The positions of the battery and its management system in their respective systems are different

In the energy storage system, the energy storage battery only interacts with the energy storage converter at high voltage. The converter takes electricity from the AC grid to charge the battery pack; or the battery pack supplies power to the converter, and the electric energy passes through the converter Convert it into AC and send it to the AC grid.

For the communication of the energy storage system, the battery management system mainly has an information interaction relationship with the converter and the energy storage power station dispatching 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 PCS of the energy storage power station's scheduling system.

2.2. The hardware logic structure is different

Energy storage management system, the hardware generally adopts a two-tier or three-tier model, and the larger scale tends to be a three-tier management system

The power battery management system has only one layer of centralized or two distributed ones, and there is basically no three-layer situation. Small cars mainly use a layer of centralized battery management system. Two-tier distributed power battery management system.

From a functional point of view, the first layer and second layer modules of the energy storage battery management system are basically equivalent to the first layer acquisition module and the second layer main control module of the power battery. The third layer of the energy storage battery management system is an added layer to cope with the huge scale of energy storage batteries.

It is not so appropriate. The best number of subordinates for a manager is 7 people. If the department continues to expand and 49 people appear, then 7 people have to choose a team leader, and then appoint a manager to manage the 7 team leaders. Beyond personal ability, management is prone to confusion.

Mapped 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 The communication protocol is different

The energy storage battery management system and the internal communication basically use the CAN protocol, but its communication with the outside, the external mainly refers to the energy storage power station scheduling system PCS, and often uses the Internet protocol format TCP/IP protocol.

The power battery and the electric vehicle environment in which it is located all use the CAN protocol, but the internal CAN is used between the internal components of the battery pack, and the whole vehicle CAN is used between the battery pack and the entire vehicle.

2.4 If the types of batteries used in energy storage power stations are different, the management system parameters will differ greatly

For safety and economic considerations, energy storage power stations often choose lithium iron phosphate when choosing lithium batteries, and more energy storage power stations use lead-acid batteries and lead-carbon batteries. The current mainstream battery types for electric vehicles are lithium iron phosphate batteries and ternary lithium batteries.

Different battery types have huge differences in external characteristics, and battery models are completely unusable. The battery management system and battery cell parameters must have a one-to-one correspondence. The detailed parameter settings of the same type of batteries produced by different manufacturers will not be the same.

2.5 Threshold setting tendencies are different

Energy storage power stations have relatively ample space and can accommodate more batteries. However, some power stations are remote and inconvenient to transport. Large-scale battery replacement is more difficult. The expectation of the energy storage power station for the battery cell is to have a long life and not to fail. Based on this, the upper limit of its working current will be set relatively low, so that the battery core will not work at full load. Neither the energy characteristics nor the power characteristics of the battery need to be particularly high. Mainly depends on the price/performance ratio.

The power battery is different. In the limited space of the vehicle, the battery is finally installed, hoping to maximize its ability. Therefore, the system parameters will refer to the limit parameters of the battery, and such application conditions are bad for the battery.

2.6 The number of state parameters required to be calculated is different between the two

SOC is a state parameter that both need to be calculated. But until today, energy storage systems do not have a unified requirement for what state parameter calculation capabilities are necessary for energy storage battery management systems. In addition, the application environment of energy storage batteries is relatively abundant, and the environment is stable, and small deviations are not easy to be perceived in large systems. Therefore, the computing power requirement of the energy storage battery management system is relatively lower than that of the power battery management system, and the corresponding single-string battery management cost is not as high as that of the power battery.

2.7 Passive equilibrium conditions are better for energy storage battery management systems

Energy storage power stations have very urgent requirements for the balance ability of the management system. The scale of the energy storage battery module is relatively large. If multiple strings of batteries are connected in series, the larger single voltage difference will cause the capacity of the entire cabinet to decrease. The more batteries connected in series, the more capacity it loses. From the perspective of economic efficiency, energy storage power stations need to be fully balanced.