Analysis, design and implementation of a new high step-up DC-DC converter with active coupled inductor network for a sustainable energy system

A DC-DC converter with a quasi-active switched-inductor structure for renewable energy systems is introduced in this paper. In the presented structure, the switched inductor method is integrated with the coupled inductor. The proposed converter consists of four capacitors, four diodes, two active switches and two coupled inductors derived from the switched inductor network and can be integrated into one magnetic core. The primary side of the coupled inductors are charged/discharged in parallel/series by the input source. Two sets of diode-capacitor, in addition to increasing the voltage conversion ratio, reduces the voltage jump caused by the leakage inductor, as a result, the voltage stress on the power switches is limited. Therefore, two switches with low conduction resistance can be used to reduce conduction losses, thus increasing efficiency. Also, two diodes do not have the problem of reverse recovery due to turn off naturally, the reverse recovery problem of the output diode is also reduced by the leakage inductor. Operating principles and steady state analysis are discussed in detail. Then, the performance of the proposed converter is compared with existing converters. Finally, a laboratory prototype was created and experimental results are presented to verify its performance.