How to resolve interference issues encountered during the EMC Pass test at the Edge Box Lab?

The edge computing box passed the laboratory EMC test, but was still subject to interference in the field. The reasons include the presence of composite interference not simulated in the laboratory or inadequate grounding of the equipment. Solutions include:

1. On-site spectrum detection: Use a handheld receiver to locate the interference frequency and intensity, and then back-test in the laboratory.

2. Check the on-site grounding system: The grounding resistance should be <0.1Ω; if insufficient, lay copper braided tape.

3. Check if the cable shielding grounding is 360° low resistance.

4. Install filters on the interference source side in the field, such as adding a ferrite core to the inverter output.

5. Add surge protectors (e.g., 5.0SMDJ33CA and Y capacitors) to the edge box's power input, and enhance common-mode filtering (CMZ3225A-501T).

6. Add fault-tolerant algorithms to the software, such as a communication retry majority voting mechanism.

After these measures, the edge box in the substation no longer reports false alarms.