Simple modulation and control method for new extended boost quasi Z-source

This paper proposes a new extended boost quasi Z-source inverter (ZSI) and a simple modulation and control method based on one-cycle control for controlling a grid connected PEM fuel cell energy system. ZSIs are gaining popularity. Similarly one-cycle controllers are becoming popular due to their simplicity, ease of implementation and fast response. However, this control method has not been developed for controlling three-phase ZSIs. Therefore, introducing and developing modulation and controllers based on one-cycle controller design for ZSIs would enable many applications to take advantage of the recently proposed ZSI. The proposed controller can be used with all voltage source type ZSIs. Contributions of this paper are introducing and applying one-cycle control to ZSI and developing a novel PWM method based saw-tooth waveform and a simple shoot-through method, where the new method eliminates the increasing of switchings per carrier cycle in the original simple shoot-through method. Also this paper proposes a closed loop controller to control the dc side of the extended boost qZSI. The proposed topology and control method are extensively simulated in Matlab/Simulink.