Fault studies in a.c. systems interconnected by h.v.d.c. links

Steady state and dynamic models of high voltage direct current transmission links, suitable for the analysis of a.c./d.c. power systems under fault conditions, are described. The New Zealand a.c./d.c. system is used to test the models with balanced and unbalanced faults. The results are used to discuss the extent of their applicability and, particularly, the scope of the dynamic simulation in the design of switchgear, protective systems and convertor controls.