Advanced Scheme for AC Voltage Control at HVDC Converter Terminals

A new economic and effective scheme for controlling the ac voltage at the HVDC terminals during both steady state and dynamic conditions is presented. By extending the basic characteristics of an HVDC converter, it is possible to affect and modulate the reactive power balance on the ac side. Analytical studies as well as digital and simulator results are presented to demonstrate the viability of the proposed ac voltage control strategy to optimize HVDC terminal design and performance for a practical system. The economic and technical features of the new scheme are discussed and compared with other ac voltage control techniques such as synchrononous condensers and static VAr compensators.