The characteristics of a new PWM-controlled GTO three-phase converter are described. An auxiliary circuit consisting of GTO thyristors was newly developed to treat the commutating energy generated in ac source leakage reactance during circuit commutation to maintain high efficiency. Various characteristics of the auxiliary circuit, snubber capacitor and the new converter circuit are investigated. The harmonic distribution curves from this PWM-Controlled method over a wide control range of modulation factor are calculated and compared with conventional ones. The new converter has high efficiency and low harmonic content. An auxiliary capacitor makes the snubber capacitor smaller and its voltage is used to limit voltage spikes generated in the ac source by controlling the conducting state of the GTO's in the auxiliary circuit.
|Publication status||Published - 1 Dec 1985|