Ripple-Free Multiphase Interleaved Stacked Converter for High-Power Applications

Abstract

A novel control technique that guarantees a ripple-free output current and voltage of a dc–dc multiphase staked interleaved converter is proposed. The conventional multiphase interleaved converters have been extensively used in various applications. However, ripple cancellation in these converters solely depends on the number of phases and can only be achieved at specific duty cycles. On the other hand, wide-range and ripple-free output are important paramount features for many modern applications. Therefore, the presented converter aims to combine the advantages of both the multiphase interleaved and the stacked converters into a single-unit converter suitable for high-power applications. Ripple-free output current/voltage is always guaranteed regardless of the number of phases and duty cycle values. This feature is accomplished by adding a fractionally-rated phase-leg to the conventional multiphase interleaved converter and modulating it with the proposed control approach. The configurable logic block, a state-of-the-art tool developed by Texas Instruments, is utilized to reduce the hardware size of the entire conversion system while increasing its speed and flexibility. Extensive simulation studies are carried out to confirm the functionality of the proposed control scheme. A laboratory porotype is developed to validate the effectiveness of the proposed control method experimentally. With only a few more components, significant reductions in output ripples are achieved.