An Automatic Control Scheme of HVDC Transmission Using Digital Techniques Part I Principles of Operation

The requirements of HVdc converter control are achieved by dicrital techniques with minimisation of circuit complexity. Feed-back control is applied to modification of the counting of clock pulses derived from the ac system by a phase-locked frequency multiplier. Symmetry of the derived firinc, oulses can be retained for all modes of operation with smooth transition from full rectification to full inversion.