DC-to-DC converter with hybrid input sources

This paper proposes a three-port dc-to-dc power conversion circuit for small-scale distributed generation systems. With the three-port converter, the load can be powered from two different dc sources, which can be a combination of two from a solar-cell panel, a fuel-cell set, a battery bank, etc. The power conversion circuit consists of two active power switches by commonly using an inductor and an output filter capacitor. By adjusting the duty-ratio of the active power switch, the voltage regulation at the output as well as the power coordination between two input sources can be made. The circuit operation is described in detail with the theoretical analysis and computer simulation. An experimental circuit has been built and tested to verify the analyzed and simulated results.