3-phase AC-drives with passive front-ends with focus on the slim DC-link topology

3-phase AC-drives for HVAC applications (heating, ventilation & air-conditioning) typically employ a passive diode rectifier and an electrolytic DC-link capacitor to filter the rectified line voltage. The DC capacitor may be accompanied by AC or DC-chokes for harmonic line- current reduction. Recently, commercial HVAC drives, where all traditional passive rectifier components are replaced with a "small" DC-link film capacitor, have emerged. These are referred to as slim DC-link AC-drives. This AC-drive is compared to traditional types below.