A DSP controlled variable-frequency resonant-commutated converter

Features of a three-phase resonant-commutated variable-frequency converter applicable in a variety of industrial applications are presented. Minimization of switching losses and hence usage of naturally commutated devices as accomplished by resonant commutation of the converter is highlighted. Design and development of the TMS320C30 DSP based controller is described. Strategies developed for switching of converter devices in relation to the resonant-commutated link are discussed. Results from Pspice simulation studies of the converter are presented. Experimental results while the three-phase experimental model of the converter supplied passive loads are enclosed and observations summarized. Comparison of results confirms potential applicability of the converter in adjustable speed drive, induction heating, welding and active filter applications.