A novel full bridge dual output DC-DC converter with complementary pulse widths and frequency modulation

A novel dual output DC-DC converter is proposed in this paper. In the proposed converter, one operational period is divided into two complementary parts, and two output branches with complementary pulse widths are structured. One output is fully regulated by the pulse width modulation; the other output is affected by the complementary pulse width but compensated by the switching frequency. Using the variable frequency phase shift modulation, only one full bridge topology is needed but two fully regulated outputs are obtained. And, all switches can achieve ZVS without auxiliary circuit by the appropriate design. Therefore the proposed topology has simply structure, fully regulated ability, high switching frequency and high efficiency. This paper focuses on the steady state analysis and design of the proposed converter. The overview of the operational principle is introduced first; then, the equivalent circuits are obtained and the new characteristics are deduced; based on the discussion, the design procedure is given and a prototype with 300 V input, 24V/10 A and 48V/5 A outputs is build to verify the analysis.