A Modified Higher Operational Duty Phase Shifted Full Bridge Converter for Reduced Circulation Current

Abstract

Besides many advantages, the reduction in the operational duty of a traditional phase shifted full converter limits its scope in applications where a wide range of input voltage is the main requirement. Operation with low duty cycle extends freewheeling interval, which results in degraded performance such as more circulating current, increased conduction loss in power devices, narrow range of zero voltage switching and increased EMI. To overcome these drawbacks, this work suggests a modified phase shifted full bridge converter that keeps the operational duty of the converter high for a wide range of input voltage. This cuts the freewheeling interval and improves performance. The proposed converter consists of four low profile transformers having a structure of reconfigurable interconnections. There are two distinct reconfigurable operational modes, a low-gain mode and a high-gain mode, which can be adopted following the variation in line voltage. The proposed work is validated in LTspice simulation and hardware characterization for a wide range of input voltage 100-400 V dc / 12 V out and up to the load power of 1.2 kW. INDEX TERMS Wide range converter, low freewheeling, reduced circulation current, high duty cycle, ZVS, resonant converter, multiple transformers, series transformers, PSFB converter, reconfigurable converter.

A 2×3 Reconfigurable Modes Wide Input Wide Output Range DC-DC Power Converter

“…By using the reconfigurable characteristics of the proposed converter along with the requirement of the intended application, the range of either side can be extended while keeping the performance stable. This work is an extension of previous work [13], [20], [21], where the solutions for extending both ranges have been separately discussed. By combining both solutions, this work introduces a novel concept of a five distinct mode isolated power converter.…”