AHD™ Active Harmonic Damping technology from Unico is a unique solution for improving power quality in variable-speed drive systems. Incorporated into Unico’ s 1200 series drives, AHD™ technology automatically dampens harmonic distortion to improve energy utilization, extend equipment life, and improve system reliability and productivity. When used in concert with other harmonic solutions, AHD™ drives provide an economical path to satisfying the IEEE-519 and similar standards.