This part of the IEC 60919 provides general guidance on the steady-state performance
requirements of high-voltage direct current (HVDC) systems. It concerns the steady-state
performance of two-terminal HVDC systems utilizing 12-pulse converter units comprised of
three-phase bridge (double- way) connections (see Figure 1), but it does not cover multiterminal
HVDC transmission systems. Both terminals are assumed to use thyristor valves as
the main semiconductor valves and to have power flow capability in both directions. Diode
valves are not considered in this report.