Servo and stepper motors and VFD have two major EMI-related problems: excessive electromagnetic interference in equipment, and damage to the motor bearings caused by excessive high-frequency currents flowing through them. Excessive EMI causes problems with measurements and equipment operation.
All pulse-width driven motors suffer deterioration of bearings (often called EDM – electric discharge machining). This article describes the problem in details. http://www.onfilter.com
OnFILTER’ patented SF/SV-series dedicated dV/dt servo and variable-frequency drives (VFD) filters and and TF/TV-series stepper motor filters and TF/TV-series transform sharp edges of drive pulses into much less “polluting” gradual ramps and also provide additional filtering in motor’s ground reducing current through bearings typically 80 to 100 times.