Synthesis of Fast Onload Multitap-Changing Clamped-Hard-Switching AC Stabilizers.

Power insulated-gate bipolar transistor (IGBT) and other gate turnoff switches have allowed to analyze, in a previous paper, four new circuits for onload-tap-changing ac stabilizers that typically permit to make up to 7 or 45 (depending on the particular circuit solution) changes per half cycle of the mains voltage. This second and last paper considers the synthesis aspects of these sub- cyclic stabilizers giving design rules, and a synthesis calculus sheet actualized in a 100-kVA numeric example. A comparative table for the four circuit solutions, involving both technical and economical figures, is given as the final step of the iterative analysis and synthesis cost comparative method performed along the research. Preliminary experimental results are obtained from a 1-kVA prototype and a first evaluation of the possibilities of reducing voltage distortions is demonstrated in the fields of voltage low harmonics and flicker by means of a high-accuracy graphic simulator. [ABSTRACT FROM AUTHOR]