Modbus Protocol for Energy Storage Converter and Battery Management

This standard specifies the communication protocol between an energy storage converter (PCS) and a battery management system (BMS) using Modbus communication. It covers the physical layer, data link layer, application layer, charging and discharging processes, security policies, communication methods, and information addresses. The protocol is based on RS485 Modbus and applies to bidirectional energy conversion systems connected to the grid and/or load. Key terms defined include energy storage converter, battery management system, frame, prohibit charging, prohibit discharging, BMS heartbeat signal, limited charging voltage, discharge limit voltage, limited charging current, discharging limited current, and state of charge (SOC). The standard ensures reliable and secure communication for monitoring battery status (temperature, voltage, current, SOC) and controlling charging/discharging operations. It references GB/T 19582.1-2008 and GB/T 19582.2-2008 for Modbus application and serial link implementation guidelines. The document includes normative appendices for Modbus RTU commands and is published by the China Chemical and Physical Power Supply Industry Association, effective February 1, 2021.