A Novel Multilevel Current-Driven DC-DC Converter for Wide Range Applications

Abstract

This article presents a novel multi-level current-driven DC-DC converter along with a modulation scheme that is able to maintain a consistently high efficiency across a wide range of input voltages. This proposed circuit is targeted to applications with a wide range of operating conditions, e.g., PV microinverters, energy storage, etc. Industry standard converters such as the flyback and the LLC resonant converter struggle to accommodate the wide range of voltages, and their efficiency suffers when operating points deviate from the nominal. The proposed approach takes advantage of the multi-level structure and flexibility of the modulation scheme to achieve high performance for a wide operating range. In addition to theoretical analysis of the operation of the converter, this paper demonstrates the functionality and performance of a laboratory prototype in direct comparison to resonant converters to show its superior performance across a wide range. The results validate the benefits of the proposed topology and show a significantly flattened efficiency curve over a wide range of input voltages (0.56% variation over an input voltage range of 32 V to 48 V).

Keywords

• DC-DC converters
• current-driven converter
• high-frequency current shaping
• half-bridge
• multilevel
• microinverter