A Quasi-Z-Source Four-Switch Three-Phase Inverter With Null Vector Capability

In this article, a novel structure for four-switch three-phase inverter with the ability of creating null vector is proposed. This utilizes symmetrical quasi-Z-source network and generates zero output voltage during shoot-through state, which similar to in conventional six-switch inverter. used remaining time each switching period. means that proposed has several advantages over inverter, two active vectors opposite directions are necessary synthesizing vector. These increase losses due current circulation through these states. Moreover, number states increases because applying vectors. However, problem does not exist topology. To decrease distortion minimize events per cycle, new pattern proposed, too. Also, fluctuations split capacitors dc-link considered closed-loop modulation method, balances voltages decreases THD by 0.7%. validate topology given pulsewidth approach, its mathematical analyses here. simulations experimental verification have been performed on 1-kW prototype