How do the PCS and BMS of an energy storage system coordinate their communication and EMC?

The communication link (typically CAN or Ethernet) between the PCS and the Battery Management System (BMS) must remain reliable in complex electromagnetic environments. EMC design for both systems must be coordinated:

1. Interface Protection Consistency: Consistent filtering and protection measures should be implemented at the communication ports of both the PCS and BMS. For example, using the same type of common-mode inductor (such as the CML series) and ESD/TVS protection devices to form symmetrical protection.

2. Grounding and Equipotential Bonding: Ensure that the communication ground (or shielding ground) of the PCS and BMS is reliably connected at a single point to avoid a potential difference between them, which could create a ground loop and introduce interference. If the distance is long or the grounding system is independent, isolated communication transceivers should be considered.

3. Communication Cable Requirements: Shielded twisted-pair cables must be used, with the shield connected to the grounding busbar of each device at both ends.

4. Protocol Fault Tolerance: The communication protocol should have strong error correction and retransmission mechanisms to handle occasional transmission errors. Both parties should reach an agreement on port EMC design specifications during the development phase and conduct joint testing.