Effective microcomputer based control of naturally commutated cycloconverter by minimum hardware and software

The design of a microprocessor-based structure for the direct digital control of a three-pulse one-phase cycloconverter is discussed. The mathematical model, the block diagram of the control circuit, and the flowchart of the program based on the cosine wave crossing pulse timing method modified by regular sampling are presented. It is concluded that the control concept may be extended to more complex structures, and that feedback control, necessary for variable-speed AC motor drives, can be achieved.<>