Non-isolated Ultra-high Voltage Gain Coupled Inductor-based DC-DC Converter

In this paper, an improved non-isolated coupled inductor-based high step-up DC-DC converter is proposed, with ultra-high voltage gain thanks to an active switched inductor. Utilizing a three-winding coupled inductor (CI) adds two more freedom degrees arising from its turns ratios that leads to a wide output voltage range. Several capacitive and inductive power transferring methods with no circulating current are used to recycle the stored energy in passive components. Two series-connected output ports and a passive clamp make the output and switch voltage stresses more tolerable, respectively. In addition, synchronized operation of switches leads to an easily implementable control system. Operation of the proposed converter in continuous conduction mode is analyzed thoroughly along with boundary and discontinuous conduction modes. Moreover, components design guideline is provided, and to evaluate the features, the converter is compared with some recent converters. Eventually, the experimental results of a 300 W laboratory prototype are given to validate the theoretical analysis.