Performance analysis of interleaved boost converter with voltage gain extension cell

A novel interleaved high step-up converter is proposed in this paper to satisfy the high power and high step-up conversion requirements. The interleaved structure is applied to reduce the input and output current ripples, which is helpful to reduce the impact to the filter capacitors. A voltage gain extension cell based on the coupled inductors is introduced in the conventional interleaved boost converter to extend the conversion ratio and reduce the switch voltage stresses. Thus, low on-resistance switches can be applied to reduce the conduction losses. Moreover, the passive lossless clamp circuits are adopted to clamp the switch turn-off voltage spikes and recycle the leakage inductance energy. Furthermore, each coupled inductor not only works as a filter inductor, but also works as a transformer with a relatively low magnetizing inductance, which benefits to reduce the volume of the magnetic cores. Finally, a 48V-input 380V-output 1kW prototype is built to demonstrate the theoretical analysis.