Comparative Analysis of Single-Phase and Interleaved Synchronous Buck Converters

In the last decade, rising global energy demands and urgent climate change concerns have prompted extensive research in efficient energy management. The need for electricity is growing due to new consumers on the power grid, such as electric vehicles, data centers, etc. In addition, the application of renewable energy sources and battery storage systems in the power grid changes the dynamic behavior of the system, and sets new requirements for the design of power electronics devices. It is known from literature that DC/DC converters represent cost-effective and energy-efficient options that have a wide range of applications in the industry and as such are an integral part of many solutions. Consequently, new criteria for DC/DC converters are being defined, focusing on dynamic and steady state performance, energy efficiency and quality of the output voltage. In this paper, starting from fundamental concepts, a behavioral analysis of buck converters based on GaN semiconductor technology is given, as a function of the number of interleaved phases operating simultaneously with a shared DC link. The analysis is based on key parameters that describe the behavior of the converter in steady state operation and during transients. Based on simulation models developed in the LT-Spice software package and for the defined output voltage range, conclusions and design suggestions are drawn, so as to achieve a compromise between output ripple, efficiency and power density. Results of the developed simulation models are verified through experimental measurements on a 1.5-kW single-phase and two-phase converter prototype.