Output waveform reconstruction of converter by fuzzy control technique

This dissertation introduces the fundamental principle of the two-variable control theory (TVCT), and puts forward the non-circumfluence control method (NCCM) of the phase-controlled converter. Using the NCCM and the TVCT, the converter doesn't have circumfluence, which is a dead belt, or doesn't need a device for zero-crossing detection. These two methods simplify the main circuit of converter. The TVCT and the NCCM give the methods of calculating the triggering instant and the pulse width of thyristors, and decide the output waveforms of converter. But sometimes the output waveforms aren't in symmetry enough. In allusion to it, This work gives the method to modify asymmetry of output waveforms by using the fuzzy control technique, and offers the fuzzy control algorithm used in the modifying process. Finally, the satisfying output waveforms are given.