How to improve the conduction immunity (CS) of industrial servo motors?

Improving the immunity of servo systems to conducted interference (CS, IEC 61000-4-6) requires addressing both the injection path and the affected circuitry. Etymotic's improvement measures include:

1) Strengthening filtering at the power input port: Using high-performance common-mode inductors (such as CMZ7060A-701T) and differential-mode inductors (PWR series), along with X/Y capacitors, to improve attenuation of injected noise from 150kHz to 80MHz.

2) Providing local voltage regulation and filtering for internal sensitive circuits (such as control ICs and ADC references): Using LDOs instead of switching regulators to power them, and connecting a ferrite bead (PBZ series) in series at the power input and a decoupling capacitor in parallel.

3) Using shielded or twisted-pair cables for susceptible signal lines (such as analog sampling and reset), and adding RC low-pass filtering at the receiving end.

4) Optimizing the PCB ground plane design to reduce common impedance coupling.

During testing, it is necessary to perform tests under rated load and monitor key performance indicators (such as speed fluctuation and positioning error). Through comprehensive design, the servo system can stably pass the 10V (Level 3) CS test.