Six-Pulse Converter Atypical Harmonics Caused by Second Harmonic Voltage

摘要

This paper reports the orders and levels of atyp- ical harmonics caused by the second harmonic voltage. Two basic types of 6-pulse converters are discussed: The L-filter (Current Source Rectifier) and the C-filter (Voltage Source Rectifier). The response of these converters to symmetrical nonsinusoidal voltage distorted by positive- and negative-sequence 2nd harmonic voltage are summarized. The most significant finding reported in this study is the fact that C-filter converters supplied with traces of positive-sequence 2nd harmonic voltage are prone to inject excessive amount of dc and even harmonic currents into the ac lines.