High step-up converter based on coupling inductor and bootstrap capacitors with active clamping

As generally acknowledged, the high step-up DC-DC converter is widely used in the sustainable energy system as the front-end stage of the DC-AC converter. Therefore, a high step-up converter combining one coupling inductor and two bootstrap capacitors, together with the active voltage-clamping circuit which pumps portion of the leakage inductance energy to the output, is presented herein. By doing so, the efficiency at light load can be upgraded greatly, and hence tends to be flat between the minimum load and the rated load. In this paper, the basic operating principles of this converter are firstly illustrated in detail, and secondly some experimental results are provided to demonstrate the effectiveness of the proposed high step-up converter topology.