How to choose between double-ended grounding and single-ended grounding for EPS?

The grounding method (double-ended or single-ended) of the cable shielding layer in EPS (Electric Power Supply) needs to be determined based on the type of interference and the cable length/application.

1. Double-ended grounding: The shielding layer is connected to the grounding busbar/chassis at both ends of the cable. This provides a low-impedance return path for high-frequency interference (>1MHz), offering good shielding performance and is suitable for suppressing high-frequency electric and magnetic field interference. It is a common method for short-distance cables within EPS cabinets. However, it can create ground loops, potentially introducing low-frequency ground potential difference interference.

2. Single-ended grounding: The shielding layer is grounded only at one end of the cable (usually at the receiving end or the equipment inlet). This effectively avoids low-frequency ground loop currents and is suitable for suppressing low-frequency magnetic field interference (<100kHz) or long-distance analog signal transmission. However, the shielding effect against high-frequency electric fields will decrease.

For EPS, where high-frequency noise is abundant within the cabinet, power lines and high-speed signal lines are typically double-ended grounded, ensuring good grounding; single-ended grounding can be considered for long-distance low-frequency analog signal lines.