Ultra-High Step-Up Interleaved Converter With Low Voltage Stress

In this paper, a new type of interleaved high step-up converter including a coupled inductor is proposed. The proposed converter has an interleaved configuration on the input side to reduce the ripple of the input current and increase the power level. Moreover, a stacked structure on the output side provides a high input/output (I/O) voltage gain. In addition, the proposed converter can avoid an extreme duty cycle, causing larger conduction losses, by combining a coupled inductor and a lossless clamp circuit with an interleaved method. These increase the efficiency by making the semiconductor device a low voltage stress and allowing the use of components with low voltage ratings. Also, the energy stored in the leakage inductor in the coupled inductor can be recycled to the output side, the MOSFETs can be partially ZCS turned ON, and the diode reverse recovery problem can be alleviated. Finally, a laboratory prototype circuit with an input voltage of 24V, an output voltage of 400V and an output of 500W was implemented to demonstrate the performance of the proposed converter.