Studies of Large AC/DC Systems on the Digital Computer

Interest in HV-dc transmission has fostered development of techniques for the study of dc systems in parallel with extensive ac systems. A digital computer program for the study of steady-state and transient behavior of combined ac/dc systems has been developed, including a detailed representation of a dc link, the capability of representing a large-scale interconnected ac system, and representation of the transient performance including the mutual effects between the ac and dc systems. The evolution and content of the program, together with representative results of studies are presented.