Design and implementation of a compact interleaved boost converter

Abstract

Interleaved topologies are well suited for high power and high performance aerospace power converter systems. The advantages of coupled-inductor interleaved boost converters include increased efficiency, reduced size, reduced electromagnetic emission, faster transient response, and improved reliability. The design, implementation, and performance evaluation of a compact 75 kHz, 2 kW, 100 V/270 V inversely-coupled interleaved dc/dc boost converter is presented in this paper. Optimization of the coupled inductor architecture in terms of ac flux balancing and dc flux cancellation is also discussed. The two-phase converter unit was implemented on a rack system with three sections in their own rack: an input section that included the coupled inductor, a power MOSFET section that included the control/driver circuit board, and an output rectifier section that included the filter capacitors. This layout and integration technique supports a modular construction approach and provides a converter system with improved noise immunity. The forced-air cooled converter prototype with dimensions of 8.2 cm × 10.8 cm × 9.2 cm and a mass of 1.2 kg unit has been tested at 2 kW of output power level, which represents a power density of 1.7 kW/kg and 2.5 W/cm3. The converter efficiency stayed above 92% over the entire load range (<1 W to 2 kW). The power density numbers are expected to double upon testing the unit at a higher power level. A description of planned development work, including operating the compact dc-dc converter at higher temperatures (up to 200°C), is included as well. This future work will include the incorporation of high temperature power semiconductor devices, an X-perm magnetic core, and both ceramic and FPE capacitors.