The performance of A.C. systems with predominant power supply by H.V.D.C. inverters

Model tests are described which have been conducted to investigate the performance of "weak" a.c. systems with d.c. injection. It is shown that system frequency can be controlled effectively by h.v.d.c, inverter stations. Switched capacitors may be used for voltage control. It is shown that power injection into a.c. systems by line commutated h.v.d.c, inverters is possible down to short circuit ratios far below 1.