In the rapidly evolving landscape of China's energy sector, Battery Energy Storage Systems (BESS) do not operate in isolation. To ensure grid stability and economic efficiency, these systems must communicate seamlessly with external entities, primarily Power Grid Dispatch Centers and Virtual Power Plants (VPPs).
Choosing the right communication protocol is not just a technical preference but a regulatory necessity. Whether a system is providing peak shaving for a provincial grid or participating in spot market trading via a VPP, the commands for charging and discharging are executed with precision and documented for financial settlement.
The Industry Standard: IEC 60870-5-104 (104 Protocol)
The IEC 60870-5-104 protocol, commonly referred to as "104". It is the mandatory standard for telecontrol communication between power plants and grid dispatch centers. Operating over TCP/IP networks (typically via Port 2404), it provides a robust framework for transmitting "Four Remotes": Telesignaling (status), Telemetering (values), Telecontrol (switching), and Tele-regulation (setpoint adjustments).
For a BESS, the 104 protocol is the primary channel for receiving critical grid instructions such as Automatic Generation Control (AGC) and Automatic Voltage Control (AVC). These commands dictate how the battery responds to frequency and voltage fluctuations. Because of its maturity and widespread adoption, the 104 protocol ensures that energy storage assets can be "seen" and "moved" by grid operators across different regions and hardware vendors.
High-Speed Intelligence: IEC 61850 and Fast Response
As energy storage moves toward "New Power System" requirements, the demand for speed has skyrocketed. This is where the IEC 61850 standard comes into play. Unlike the 104 protocol, which is optimized for wide-area monitoring, IEC 61850 (utilizing MMS, GOOSE, and SV) is designed for high-speed, peer-to-peer communication within intelligent substations. It allows for control response times in the millisecond to microsecond range, which is essential for specialized functions like primary frequency regulation and transient stability support.
In modern "smart" energy storage stations, it is common to see a hybrid architecture where 104 and 61850 coexist. This dual-protocol approach balances the need for standardized administrative reporting with the technical requirement for near-instantaneous physical response, ensuring the storage system is both compliant and high-performing.