How can grounding of a smart controller (PAC) system improve overall EMC?

Improving the system grounding of the PAC (Power Acoustic Controller) significantly enhances overall EMC performance. The system grounding design includes: establishing a layered grounding structure, progressively reducing impedance from equipment level and rack level to building grounding level; employing a combined grounding method, sharing a grounding network for lightning protection ground, protective ground, and working ground, with a grounding resistance of less than 1Ω; internally, connecting digital ground, analog ground, and power ground to the system ground trunk at a single point via ferrite beads (such as PBZ1608A-102Z0T); simultaneously installing noise filters (such as power filters) and surge protectors (such as GDTs) on the system grounding busbar; optimizing the grounding path to avoid parallel routing with high-voltage cables; after overall grounding optimization, the PAC system's conducted emissions in the 150kHz-30MHz range can be reduced by 25dB, radiated immunity improved by 20dB, and it passes the IEC61000-4-5 surge test (4kV) and IEC61000-4-6 conducted immunity test (10V); the system-level EMC meets the requirements of the GB/T 17626 series standards.