High Step-Up Interleaved Converter Mixed with Magnetic Coupling and Voltage Lift

Abstract

In this paper, a non-isolated high step-up interleaved DC-DC converter for distributed generation applications such as solar cells and fuel cells. The proposed converter mixes the benefits of magnetic coupling, voltage multiplier, and voltage lift techniques to conventional interleaved schemes. The proposed converter's voltage lift technique can increase the voltage gain while guaranteeing low voltage stress of the switches. And the magnetic coupling method can combine the switched capacitor of the voltage multiplier technique with the lossless clamp circuit to achieve high voltage gain and reuse the leakage inductance energy to the output terminal. In addition, this leakage inductance energy can achieve zero current switching turn on soft switching performance and mitigate the output diode reverse recovery problem. The proposed converter avoids the extreme duty cycles that cause conduction losses in power devices and can give very low voltage stresses. Therefore, the use of low voltage rated MOSFETs and diodes not only reduces switching losses and costs, but also improves efficiency.