A predictive control strategy for improving HVDC converter voltage profile

A control strategy is presented to enhance the converter bus voltage profile for HVDC systems with power modulation capability. A two-terminal HVDC system is considered. The algorithm predicts the value of reactive power needed to maintain a preset converter bus voltage for a specified value of the DC power during the modulation period. The necessary value of DC voltage at the inverter station is computed to match the predicted and demanded values of reactive power. From the computed inverter DC voltage, the value of DC current and the reactive power demand of the rectifier station are obtained. The difference between the predicted and demanded value of the reactive power at the rectifier station, referred to as the required value, is provided by a static VAr compensator. Analytical and simulated results are included to verify the validity of the proposed control strategy