An interleaved ultra-high step up DC-DC converter with low voltage stress

This paper proposes a new ultra-high step up converter by employing coupled inductor and interleaved techniques. Winding cross coupled inductors are utilized to enhance the conversion ratio and reduce the voltage stress of semiconductor components. Low voltage stress of switches makes it possible to use low on-resistance power switches. The conversion ratio of the proposed interleaved converter is extended by integrating with voltage lift circuits. The current flows into coupled inductors and the input current ripple is reduced because of the interleaved structure. The spike voltage of the switches is restricted by the clamp circuit. Main specifications of proposed interleaved converter are ultra-high voltage gain, low input current ripple, low voltage stress, low current stress, low core size, small volume, low reverse recovery loss of diodes, low conduction loss and high efficiency. The 18 V to 450 V prototype circuit is implemented at 100 W and its experimental results are presented which ascertains theoretical analysis.