Simulation of h.v.d.c. systems in a.c. load-flow analysis by digital computers

The paper presents a suitable method by which h.v.d.c. trunk lines may be simulated for the purpose of load-flow analysis by digital computer of a.c. power systems containing one or more d.c. transmission links. An explanation is given of the derivation of the relevant equations which comprise a small routine capable of being inserted into normal a.c. load-flow programs. The representation of the d.c. link in an a.c. system is best achieved by equivalent current generators at those a.c.-system nodes containing the convertor terminals. The relationship between the injected currents and the voltages at the nodes is defined by the proposed routine, which is accurate and fully equipped with h.v.d.c.-system controls.