How can EPS safety standards and EMC be designed simultaneously?

The safety and EMC design of EPS (Electrical Power Filter) must be carried out simultaneously, as they are interconnected and may conflict. Key points for simultaneous design:

1. Coordinated consideration of insulation and filtering: Safety regulations require electrical clearances and creepage distances, which limit the bridging position of Y capacitors and the placement of varistor in EMC filters. The capacitance value of Y capacitors is limited by leakage current, directly affecting common-mode filtering performance. Y capacitor configuration must be optimized within the leakage current limits allowed by safety regulations.

2. Coordination of grounding and protective conductors: Safety regulations require reliable protective grounding, consistent with the low-impedance grounding requirements of EMC. However, safety grounding conductors primarily consider power frequency fault currents, while EMC focuses on high-frequency impedance; therefore, short, wide conductors or planes are needed to simultaneously meet these requirements.

3. Component certification: Filtering and protective components (such as X/Y capacitors, varistors, and filters) should be selected from products that have passed safety certifications (such as UL, VDE, CQC).

4. Collaborative risk assessment: In FMEA (Failure Mode and Effects Analysis), both safety failures and functional safety risks caused by EMI must be considered. Close communication between engineers from both sides is necessary during the design process to find the optimal solution.