Multi-level current reinjection in double-bridge self-commutated current source conversion

A new self-commutated current source converter is proposed, based on the reinjection of multi-level dc current pulses via a GTO-switched multi-tapped interphase reactor. The ideal reinjection waveform for complete elimination of the harmonic content of the ac system side current is derived and a practical approximation proposed to increase the pulse number of the double-bridge converter to any multiple of twelve. A 48-pulse configuration is analyzed in detail to show the new concept effectiveness on both the ac and dc sides of the converter.