A Novel Modulation Scheme for Isolated PWM Active-Clamp Ćuk DC/DC Converter

A novel modulation scheme for a bidirectional isolated pulsewidth modulation active-clamp (PAC)-Ćuk converter is presented in this article. In the PAC-Ćuk converter, the clamping circuit consisting of a capacitor, a series inductor, and an active device enables zero-voltage-switching (ZVS) turn-on capability of all the active devices. This additional circuit equips the converter with three independent control parameters. This article discusses power transfer, ZVS region, and circulating current dependency on the control parameters across the converter gain. Minimal circulating current is generally desired to decrease the conduction losses. With the help of the proposed modulation technique, the optimization of the control parameters to achieve lower circulating current while ensuring ZVS operation is also discussed. A 2-kW experimental converter is also designed and fabricated to validate the analysis.