Ultrahigh Step-Up DC-DC Converter Composed of Two Stages Boost Converter, Coupled Inductor, and Multiplier Cell

In this article, an ultrahigh step-up dc-dc converter is proposed with a combination of two stages boost converter, a coupled inductor, and a multiplier cell. The secondary side of the coupled inductor is unified with the multiplier cell. In addition, leakage energy of the coupled inductor is recycled and transferred to output perfectly which causes high-efficiency performance. The main advantages of the converter include its high voltage gain, low voltage stress on its power switches, and requiring a smaller inductor on low voltage side of the converter. Power losses of the inductors are low due to the current sharing between the input inductor and the coupled inductor. Continuity of input current and existence of a common ground between the load and source make the converter suitable for different applications. The converter is compared with the other converters based on an analysis of its operation modes. Validity of the analysis and the converter performance are experimented using a 150-W prototype that converts 20 V from the input side to 400 V in output.