Behaviour of multiterminal a.c.-d.c. interconnections with series-connected stations

All the existing h.v. d.c. schemes are varieties of point-to-point interconnection between two a.c. systems. However, multiterminal interconnections are being proposed and considered, together with general problems of a.c.¿d.c. multiterminal schemes. In this paper, the behaviour of series d.c. links is investigated as regards various types of convertor control and these are discussed and analysed. A mathematical model is developed for the solution of steady-state problems of the overall system under balanced conditions and with normal convertor operation. Results are obtained for a sample case of a 3-terminal single-source system both with and without compounding.