Experimental Study of the Shoot-Through Boost Control Methods for the Z-Source Inverter

This paper presents a simulation and experimental comparative analysis of the Z-source inverter (ZSI) with four different shoot-through (ST) control methods, namely: the simple boost control, the maximum boost control, the maximum constant boost control and the modified space vector modulation boost control methods. A review of these methods is presented with a summary of all expressions. A prototype of a 30 kW ZSI is designed and implemented. The eZdsp (TM) F2808 evaluation board is used for the realization of the shoot-through control methods and the real time workshop (RTW) is used for automatic code generation. The paper compares between the different four shoot-through control methods in terms of: the line voltage harmonic, the phase current harmonic, the d.c. link voltage ripples, the switch voltage stress, the inductor current ripples, the obtainable a.c. output phase voltage and the overall efficiency with detailed simulation and experimental results. In addition, the paper presents the effect of varying the d.c. input voltage and the shoot-through duty ratio on the overall inverter efficiency. The maximum constant shoot-through boost control method seems to be the most suitable shoot-through control method for the ZSI Also, it is shown that the efficiency of the ZSI improves with increasing the d.c. input voltage and degrades with increasing the shoot-through duty ratio.