Efficiency-based current distribution scheme for scalable digital power converters

The trend in next-generation switched-mode power supplies will lead to modular, scalable solutions, which deliver power efficiently over a wide range of operation. This paper details a new approach to introduce more advanced control features to improve system efficiency into these scalable solutions. While these methods have been incorporated into multiphase converters in the past, they all require the distribution of information among the individual converters. An advantage of the proposed method is that it does not require such communication signals between the individual power supplies and is, therefore, fully scalable and cost effective. A system comprising individual, smart converters is proposed, where each converter regulates its respective output power to a level with high efficiency. Converters not required for the delivered output power are shut down. The proposed approach is analyzed theoretically. Implementation details for a field-programmable gate array experimental prototype system are given. The system performance for a four-converter prototype system is analyzed and discussed. The efficiency obtained is compared with the efficiency of a multiphase system with phase-shedding operation and the efficiency of a system with independent power converters without phase-shedding support.