Non-Isolated High-Gain DC-DC Converter for Hybrid-Inverter Application

Hybrid-inverters are using PV and battery as their input sources. However, low voltage of the input sources is the main challenge of the PV panel level design of this system. In this paper, a non-isolated high-gain bidirectional DC-DC converter for the hybrid-inverter application is proposed. The converter provides the merits of both switched-inductor and switched-capacitor converters. The proposed converter employs two inductors connected either in series or parallel configurations during discharge or charge state. Also, this converter uses two different duty-cycles to reach a wide voltage gain range with low voltage stress on the power switches. Besides, synchronous rectification is adopted to obtain zero voltage switching (ZVS) during turn on and turn off dead time and thereby, efficiency of the converter is increased. Finally, a 300W converter with high-voltage side (300V) and low-voltage side (30~48V) has been built to demonstrate the experimental validation of the proposed converter.