A comparison of parallel resonant converters operating in lagging power factor mode

Three different parallel resonant converter (PRC) configurations are compared for their performance. The discontinuous capacitor voltage mode is emphasized in the comparison and is shown not to exist in the case of PRC with the resonating capacitor on the primary side of the high-frequency (HF) transformer. It is further shown that the condition for discontinuous capacitor voltage (DCV) mode in the case of a PRC with the assumption of an ideal HF transformer and a PRC with secondary-side resonance differ only in the ratio M/(M+L+L_p), which is equal to 1.0 for PRCs with the assumption of an ideal HF transformer. The comparison study shows that the PRC with the resonating capacitor on the primary side of a nonideal HF transformer is more appropriate for low-voltage high-current applications, while the PRC with resonating capacitor on the secondary side of a nonideal HF transformer is better suited to supply large-voltage medium- and low-current loads. Experimental results obtained from prototype units designed and built are presented to support the theory