High efficiency (90% or higher) conventional power converters for DC power supplies operate at low switching frequencies (200Hz or lower) and require bulky magnetic elements. These systems are large and expensive, and achieve low power densities of 10 W/in or lower. New power conversion circuit architectures containing semiconductor devices have been demonstrated successfully to dramatically reduce the size and cost of power converters in low power (10-100W) grid interfaced converters. This technology introduces high-frequency power converter designs that are capable of operating in high-power level systems from ac universal input voltage. Furthermore, the invention reduces the size and cost of conventional power converters by using relatively small passive energy storage components instead of the large storage components used in conventional power conversion systems.