INTEGRATED OPTIMUM CONTROL OF QUASI-DIRECT CONVERTERS

This paper deals with control and design of quasi-direct converters, i .e., ac/ac converters including a forced-commutated rectifier, an inve rter, and a small filter in the dc link. Converter performance can be optimized by means of a predictive digital control strategy, which ens ures instantaneous input-output power balance, fast response, and high power factor. After a discussion of the control strategy, the paper g ives design criteria of both power and control sections. Experimental results of a 2.5-kVA prototype are reported.