This part of 60076 International Standard specifies requirements of liquid-immersed three-phase and single-phase converter transformers for use in high voltage direct current (HVDC) power transmission systems including back-to-back applications. It applies to transformers having two@ three or multiple windings. This document does not apply to ?C converter transformers for industrial applications (see IEC 61378-1 or IEEE Std C57.18.10); ?C converter transformers for traction applications (see IEC 60310).