Communication between the Energy Storage BMS and the EMS and PCS

Communication between the Energy Storage BMS and the EMS

The display screen of the master controller unit (BMS) displays information about the entire PCS battery stack and transmits this information to the monitoring system (EMS) via Ethernet (RJ45). This information includes battery cell, battery pack, and battery cluster information.

Upload Information: The BMS uploads battery cell (or group) information, including: cell voltage, battery pack voltage, charge and discharge current, maximum cell SOC, minimum cell SOC, minimum cell SOH; battery pack SOC, maximum cell temperature, minimum cell temperature, ambient temperature, as well as battery abnormality alarms and protection information.

Receive Information: The BMS receives battery operating parameters from the monitoring system (EMSQ), such as voltage protection and alarm setpoints, temperature protection and alarm setpoints, and SOC protection and alarm setpoints.The BAMS management server supports the MODBUS communication protocol, which requires a dedicated protocol point table. The communication interface is network RJ45 communication.

Communication between the Energy Storage BMS and the PCS

Since the PCS only connects to multiple battery packs, BMS data is aggregated and sent to the BAMS. Communication between the BAMS and the PCS is one-way, with the BAMS acting as the master and the PCS acting as the slave.

BMS Information Transmission: The BMS transmits information such as battery status and alarm levels. This includes the battery pack's maximum SOC, minimum SOC, maximum charge capacity, maximum discharge capacity, ambient temperature, and minimum SOH. Upon receiving BMS alarm information, the PCS should take appropriate protective actions. 

Communication Interface: The PCS and BMS utilize a CAN or RS485 communication interface.

Hard Node Information: To ensure timely and reliable protection, the energy storage system reserves hard nodes. When the BMS detects that the battery system has reached a protection limit, it transmits the protection limit value to the PCS via the node.

(Dry contact: Similar to a hard contact, the difference is that a hard contact is implemented by voltage control, while a dry contact is implemented by current control. Dry contact also refers to a passive contact, which only has contact output and no power supply inside the contact circuit. Dry contact: A hard contact means that the hard contact itself is not charged.)