2대의 임베디드 Z-소스 컨버터를 이용한 단상 DC-AC 인버터

Abstract

In this paper, a single-phase DC-AC inverter using two embedded Z-source converters is proposed. The proposed inverter is composed of two embedded Z-source converters with common DC source and output AC load. The output AC voltage of the inverter is obtained by the difference of output capacitor voltages of each converter. The output voltage of each converter take shape of the asymmetrical AC waveform centering zero voltage. Therefore, the proposed inverter can generate the same output voltage despite low VA rating L-C elements , compared to the conventional inverter using high DC voltage with AC ripple. To verify the validity of the proposed system, the PSIM simulation was achieved under the condition of rapid increase of DC source (110[V]→150[V]) and R-load (50[Ω]→300[Ω]). For controlling the voltage of the inverter system, the one-cycle controller was adopted. As results, the proposed inverter output the constant AC voltage (220[V]rms/60[㎐]) for all conditions. Also, the R-L load and nonlinear diode load were adopted for the proposed inverter loads, and we could know that the its output voltage characteristics were as good as the pure R-load. Finally, the RMS and THD of output AC voltage were examined for the different loads, input DC voltages and reference voltage signals.