Harmonic Reduction Methods at DC Side of Parallel-Connected Multipulse Rectifiers: A Review

This article gives a detailed literature review of harmonic reduction methods at the dc side of parallel-connected multipulse rectifiers (MPRs). First, passive and active harmonic reduction mechanisms are derived. Then, some commonly used and novel dc-side passive, active, and hybrid harmonic reduction circuits are discussed in terms of their structures, operation principles, and harmonic elimination performances mainly reflected on input current total harmonic distortion (THD) values. Comparisons of their design complexity, reliability, adaptability, and other aspects are also considered. Finally, simulation results are presented to verify the effectiveness of the reviewed dc-side harmonic reduction methods. This article can provide a guideline for selecting or designing rectifiers with reduced dc-side harmonics for specific applications. Anticipated trends in MPRs with lower harmonic content are also summarized.