A novel variable frequency resonant commutated converter

A novel topology of a resonant link converter employing resonant commutation is presented. Since resonant commutation of the link is accomplished, switching losses are minimized without increased conduction losses and devices of the converter are of the natural commutated type, i.e., SCRs resulting in lower costs in comparison to forced commutated converters. Additionally, harmonic elimination by sinusoidal pulse width modulation (SPWM) techniques enables near sinusoidal currents at both the input and output lines. The emphasis of this paper is on the variable frequency performance of the converter with potential applications in adjustable speed drives. The converter while operating with greater stored energy in the link, possesses better current holdup capabilities during a contingency which cannot be achieved in a conventional resonant DC link converter. Discussion of simulation results and experimental verification of the novel concept are presented