Development of DC to Single-phase AC Voltage Source Inverter with Active Power Decoupling Based on Flying Capacitor DC/DC Converter-Hiroki Watanabe, Tomokazu Sakuraba, Keita Furukawa

Abstract—In the present, an power decoupling method without additional component is proposed for a DC to Single-phase AC converter, which consists of a flying capacitor DC/DC converter (FCC) and the voltage source inverter (VSI). In particular, a small flying capacitor in the FCC is used for both a boost operation and a double-line-frequency power ripple reduction. Thus, the DC link capacitor value can be minimized in order to avoid the use of a large electrolytic capacitor. In addition, component design, of e.g., the boost inductor and the flying capacitor, is clarified when the proposed control is applied. Experiments were carried out using a 1.5-kW prototype in order to verify the validity of the proposed control. The experimental results revealed that the use of the proposed control reduced the DC link voltage ripple by 74.5%, and the total harmonic distortion (THD) of the inverter output current was less than 5%. Moreover, a maximum system efficiency of 95.4% was achieved at a load of 1.1 kW. Finally, the high power density design is evaluated by the Pareto front optimization. The power densities of three power decoupling topologies, such as a boost topology, a buck topology, and the proposed topology are compared. As a result, the proposed topology achieves the highest power density (5.3kW/dm3) among the topologies considered herein.

 Index Terms—Photovoltaic system (PV), Flying capacitor DC/DC converter, Active power decoupling, Power density design

LINK:http://itohserver01.nagaokaut.ac.jp/itohlab/paper/2018/20180301_IEEE_TPEL/watanabe.pdf