2021 Volume 10 Issue 3 Pages 393-401
This paper describes a high-frequency-isolation circuit that uses a three-phase transformer with a zero-phase current. The proposed circuit contains a bidirectional chopper circuit and a three-phase high-frequency isolation circuit. The bidirectional chopper circuit controls the DC bus voltage of the first circuit independent from the input voltage source. Thus, the ratio of the DC bus voltage of the first circuit to that of the second circuit can be controlled, which is important in controlling the high-frequency isolation circuit. This study theoretically analyzes the proposed circuit and obtains typical circuit waveforms by simulation. In addition, experimental results using the proposed circuit are discussed. The efficiency of the proposed circuit is measured and compared for each DC bus voltage value. As a result, the proposed circuit can be effectively used for demand control such as in energy storage systems including battery PCS because of its high efficiency using a full-ranged soft-switching technique by controlling the DC bus voltage.
