This part of IEC 60146 applies to all types of semiconductor converters of the self-commutated type including power converters which contain at least one part of a self-commutated type, for example a.c. converters, indirect d.c. converters, direct d.c. converters. The requirements of IEC 60146-1-1 apply also to self-commutated converters as far as they are not in contradiction with this standard. For some special applications, for example, uninterruptible power systems, variable speed a.c. and d.c. drives and electric traction equipment, additional standards may apply. NOTE Test restrictions may apply to special applications, for example high-power reactive power converters