Single-bridge unit-connected HVDC generation with increased pulse number

A true unit-connected generator-high-voltage direct-current-(HVDC) converter scheme that eliminates the need to use two bridges in series to achieve twelve-pulse operation is proposed. Moreover, the combination of a single main bridge and an auxilliary feedback DC ripple reinjection bridge is shown to increase the pulse number from 6 to 18. This is achieved purely by natural commutation and is equally valid for rectification and inversion. The theoretical waveforms are validated by extensive experimental verification.>