Current Distortion Reduction in Six-Pulse Parallel-Connected AC/DC Rectifiers

This paper presents an innovative method for reducing current distortion on the ac side of six-pulse parallel-connected ac/dc rectifiers. The principle of the method is to modify the current waveforms on the dc side of the rectifier by using two self-commutated switches (insulated-gate bipolar transistors). It is demonstrated that accurate shaping of currents on the dc side achieves low distortion levels in currents , and on the ac side. The effectiveness of the method is confirmed by laboratory recordings, which are related to steady-state and transient studies.