Patent ID: 7061743

Claim:
A multi-pulse HVDC(High Voltage direct Current) system, the system comprising: an upper side thyristor converter ( 12 ) and a lower side thyristor converter ( 13 ) installed in a Δ-Δ-Y transformer ( 11 ), and two current smoothing reactors ( 39 ), two direct voltage dividing condensers ( 38 ) and two thyristors (T 1 , T 2 ) connected to one double winding transformer ( 31 ) wherein a Y-valve 6-pulse and Δ-value 6-pulse are selected through an even/odd pulse selector ( 42 ) by receiving a firing pulse ( 41 ), 12-pulse from two thyristors (T 2 , T 1 ) and wherein a signal is detected through Y-valve pulse generator ( 43 ) and Δ-value pulse generator ( 44 ) with respect to the selected pulse, and the above detected signal sates the T 1 value and T 2 values through latches ( 45 , 46 ) for preventing a decrease of the signal.