Harmonic Line Currents in Large Thyristor Six-Pulse Converters

A guide to the generated line currents from six-pulse converters is presented. Included are the effects of commutating reactance, phase angle retard, partially inductive loads, and general comments on plant distribution layout, especially electrochemical plants. It is intended as a concise general guide to predicting the level of harmonics to be expected in a specific case, and as a guide in minimizing the occurrence of the more complex circuit effects of a total system. Harmonic currents in large thyristor converters, Megaverters ®, are found to be not significantly greater than in diode converters; however, more care must be given to plant layout of multiphase systems in order to benefit from the attempt at harmonic reduction.