New topology and analysis of a single phase delta modulated cycloconverter

New power circuit topologies for single-phase to single-phase, and three-phase to single-phase cycloconverters (frequency changers) are proposed in this paper. The proposed power circuits use bidirectional switches as control switches in cycloconverters. As a result of using bidirectional switches, the number of expensive controlling switches is reduced to half of those in conventional cycloconverters using unidirectional switches. Cost and complexity of power circuits are greatly alleviated due to the incorporation of bidirectional switches. Analysis and implementation of delta modulated switching of a cycloconverter is also presented in this paper. Delta modulation (DM) is simple and has characteristics advantageous to the operation of cycloconverters. DM switching of cycloconverters and the analysis of the modulated waveforms are outlined in this paper. Theoretical and experimental results of a delta modulator and single-phase to single-phase cycloconverter waveforms are presented. The topologies of three-phase to single-phase conversion using bidirectional switches with typical output waveforms and their spectra are also briefly discussed.