Current boosted active clamp forward converter without output filter

Abstract

Many isolated DC/DC converter topologies suitable for high efficiency is presented. All of them try to reduce power loss by minimizing the number of magnetic components. Generally, converter topologies which have no output-inductor for DC/DC converter has no loss of it. Therefore they are suitable for high power density and high efficiency application. Active clamp flyback converter and output-inductor-less forward converter are representative converters without output inductor. However, these converters have critical problems. In active clamp flyback converter, DC offset current which degrades transformer utilization and makes transformer bulky. Therefore it causes low power density. In the other side, output-inductor-less active clamp forward converter has high RMS value of current which causes heat problem and low efficiency. This paper proposes a current boosted active clamp forward converter without output filter. Due to applying the proposed current boost-up circuit, the proposed converter has low conduction loss and low voltage ringing of the secondary rectifier. This paper presents the operational principle and design consideration of the proposed converter. Experimental results are demonstrated to verify the feasibility and advantages of the proposed converter.