How can electromagnetic compatibility and functional safety be balanced in a power storage system (PCS)?

Electromagnetic compatibility (EMC) design and functional safety (such as ISO 13849, IEC 62061, or IEC 62109 for photovoltaics) of PCS are complementary and must be considered simultaneously. EMC is a prerequisite for functional safety because electromagnetic interference can cause safety functions to fail. Key design considerations include:

1. Enhanced EMC for safety-related circuits: Circuits implementing safety functions (such as emergency stop circuits, insulation monitoring, and fault detection circuits) require higher levels of EMC protection, such as stronger filtering, more comprehensive shielding, and the use of highly immune isolation devices.

2. Redundancy and diagnostics: Hardware redundancy and periodic self-diagnostics are commonly used in safety designs, which can detect and tolerate occasional errors caused by EMI.

3. Fail-safe design: Ensuring that the system can enter or remain in a predefined safe state in the event of EMC interference or component failure.

4. Analysis and Verification: The system needs to undergo FMEA (Failure Mode and Effects Analysis) and FTA (Fault Tree Analysis) to take EMI as a potential cause of failure and verify it through rigorous EMC and functional safety tests.