Abstract
A new hybrid DC converter is proposed and implemented to have wide voltage variation operation and bidirectional power flow capability for photovoltaic power applications. The hybrid DC converter, including a half- or full-bridge resonant circuit, is adopted to realize the bidirectional power operation and low switching losses. To overcome the wide voltage variation problem (60 V–480 V) from photovoltaic panels due to sunlight intensity, the full-bridge structure or half-bridge structure resonant circuit is used in the presented converter to implement high or low voltage gain under a low or high input voltage condition. Using a pulse frequency modulation (PFM) scheme, the voltage transfer function of the resonant circuit is controlled to regulate the load voltage. Due to the symmetric circuit structures used on the primary and the secondary sides in the proposed converter, the bidirectional power flow can be achieved with the same circuit characteristics. Therefore, the proposed converter can be applied to battery stacks to achieve charger and discharger operations. Finally, a 400 W prototype is implemented, and the performance of the proposed hybrid DC converter is confirmed by the experiments.
Highlights
Bidirectional DC converters [1,2,3,4,5,6] have been proposed to interface between the different DC voltage buses for renewable energy sources, battery chargers/dischargers, uninterrupted power supplies, and electric vehicles
Only forward power flow can be realized in these circuit topologies
One AC switch and one hybrid half/full-bridge circuit structure are used on both the primary-side and secondary-side to achieve wide voltage input operation and bidirectional power flow operation
Summary
Bidirectional DC converters [1,2,3,4,5,6] have been proposed to interface between the different DC voltage buses for renewable energy sources, battery chargers/dischargers, uninterrupted power supplies, and electric vehicles. Symmetric CLLC converters have been proposed in [15,16] to accomplish forward and reverse power flow operations for DC distribution systems and battery charging/discharging systems. One AC switch and one hybrid half/full-bridge circuit structure are used on both the primary-side and secondary-side to achieve wide voltage input operation and bidirectional power flow operation. The benefits of the proposed converter are as follows: (1) wide voltage operation from 60 V–480 V input; (2) symmetric circuit on both the primary and secondary sides to have the same voltage transfer function for backward and reverse power operations; and (3) soft switching operation on power semiconductors due to resonant circuit characteristics with frequency modulation.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
