How to eliminate ground loop interference in the PCS of an energy storage system?

Ground loop interference in PCS originates from potential differences between different grounding points or the spatial magnetic field picked up by the loop, inducing common-mode noise current in the loop. Elimination methods include:

1. Optimizing grounding strategy: Using single-point grounding for low-frequency circuits to completely avoid loops; using low-impedance grounding planes for high-frequency circuits.

2. Breaking loops: Using common-mode chokes on susceptible signal lines, for example, using CML series common-mode inductors in communication interfaces to suppress common-mode interference without affecting differential signals.

3. Electrical isolation: Using optocouplers, isolation transformers, or isolation operational amplifiers to completely disconnect the ground connection.

4. Shielding and grounding: Using shielded cables and grounding the shielding layer at a single point at the equipment entry point.

5. Proper wiring: Keeping sensitive signal lines away from high-power ground return paths.

The core principle is to provide a path for interference current that is superior to the signal loop (lower impedance or complete isolation).