Comparison of voltage control devices at HVDC converter stations connected to weak AC systems

The control of AC voltage at the commutating bus following a disturbance is required for satisfactory operation of converters connected to weak AC systems. In the past, the synchronous compensator has been exclusively used as a voltage control device (VCD). However, recently a number of static VCDs have been proposed and applied to replace or supplement it. The authors investigate and compare the digitally simulated performance and estimated cost of a number of these VCDs, including a novel scheme using a series capacitor, and outline the merits and demerits of each