| Title |
LCCT Z-Source AC-AC Converter with the Improved Switching Ripple of the Input Current |
| DOI |
http://doi.org/10.5207/JIEIE.2022.36.4.009 |
| Keywords |
Inductor-Capacitor-Capacitor-Trans (LCCT) topology; Improvement of the switching ripple; Three-winding high frequency transformer; Z-source AC-AC converter |
| Abstract |
In the conventional trans-quasi Z-source AC-AC converter(TqZAC) method, the voltage gain can be improved by replacing the inductor of the Z-impedance network with a high-frequency transformer, but there is a problem in that a switching ripple occurs in the input current and the capacitor voltage. In this study, the Inductor-Capacitor-Capacitor-Trans Z-source AC-AC converter (LCCT-ZAC) method was presented to solve this problem. The proposed method replaces the conventional harmonic transformer with a three-winding high-frequency transformer and capacitor to alleviate the switching ripple problem of the previous method, while controlling the output voltage with in-phase boost and out-of-phase buck-boost for the input voltage. To prove the validity of this study, PSIM simulation and DSP-based experiments were performed. As a result, the output voltage was controlled by the in-phase boost mode at duty ratio D=0.15 and the out-of-phase buck mode at D=0.5. Also, the efficiency with respect to the change of duty ratio D under the load condition of 50Ω and the efficiency with respect to the load change under the condition of D=0.05 were almost the same between the two methods. |