Application of a Precise Continuous Power Amplifier to the SQS-26Sonar.

摘要

The system accepts 3-phase, 60 Hz power into a conventional rectifier that produces positive and negative dc voltages. These dc voltages are then switched at the desired output frequency (generally 400 Hz) to produce the 'center' portion of the wave. This center is 60 electrical degrees wide. On either side of the center is added a staircase wave. This wave is ascending one side and descending on the other. Since a three-phase system each phase is 120 degrees apart, 3 center switches and 2 staircase generators plus a set of 6-phase selectors are sufficient to create all of the required waveforms. This organization produces a lightweight converter capable of driving loads of any power factor. Its performance is essentially that of a three-phase alternator. The harmonic distortion in the converter output can be any value desired by the addition or deletion of steps in the staircases. The 60-degree center portion remains fixed in any case. The actual step widths and heights are selected by means of an optimization program.