Two-stage asymmetrical Γ-Z-source inverter with high voltage gain and reduced shoot-through duty ratio

摘要

This study presents a novel inverter with high voltage gain based on asymmetrical Γ-Z-source topology. It employs one diode, one inductor and two capacitors more than the basic structure that obtains higher output voltage with reduced duty ratio. So, a reasonable modulation ratio is needed to gain desired boost factor which improves the network power quality. In this structure, unlike other Z-source topologies such as two-stage Quasi Z-source inverter, higher stages are not required for voltage gain boosting, owing to a Γ-shape coupled inductors is used in impedance network. This unique coupled transformer raises voltage gain significantly by lowering turns ratio that reduces the cost, volume and improves the efficiency. Moreover, the two-stage asymmetrical Γ-Z-source inverter is able to operate both in buck and boost mode and its input current is continuous. The proposed inverter is analyzed in steady state and simulation results are presented to verify the performance. As well as, simple boost control is used for simulations.