Twelve-pulse back-to-back AC/DC conversion for reactive-power control

As an alternative to existing thyristor-controlled compensators, the paper proposes the use of static AC/DC power convertors for the control of reactive power. A double-bridge convertor scheme, with the two bridges operating back-to-back, is used to investigate the optimal operating conditions with respect to fundamental power and harmonic distortion. The results indicate that it is possible to maintain quasi-12-pulse operation while providirg the full range of reactive-power compensation, with and without transformers phase-shifting.