Experimental investigations into the performance of cycloconverter propulsion systems employing tandem ac ac generators

A laboratory sized propulsion system has been developed at the Royal Navy Engineering College (RNEC) to investigate the performance and noise problems associated with an ac propulsion system employing six-pulse cycloconverter variable speed drives and induction motors. Cycloconverter output waveforms contain low frequency harmonic components which give rise to additional propulsion motor noise and vibrations and pollution of the ship's electrical service system. Input current harmonics have been attenuated using an active filter, output cycloconverter harmonics have been attenuated using jitter control, and propulsion motor stator current harmonics have been attenuated with a parallel drive.