High-pulse series converters for HVDC systems

In this work a novel concept has been developed, whereby series-connected converters with any desired number of pulses can be obtained without complicated circuitry. A complete theoretical treatment and experimental verification are carried out in this paper to fully validate the concept. This generalization is achieved by adding an extra circuitry to a conventional converter connection. Besides, pure natural commutation is used and the concept is equally valid for rectification and inversion. Also, the application of the concept on HVdc systems, to reduce harmonics that are normally injected into the ac and dc networks, is analyzed. Therefore, the elimination of harmonic filters and their inherent complexities in conventional installations may be possible.