I. Introduction
Z-source converter is an innovative technology presented in recent years [1]. It's a new type of converters besides the other two kinds of traditional converters: the voltage-source and the current-source converters. It employs a unique impedance network to couple the main circuit of the converter to the power source. With proper control, the Z-source converter can buck or boost voltages to a desired magnitude, which might be greater than the available bus voltage. The Z-source converter uses shoot-through state to boost the voltage. Therefore shoot-through state now is one of the converter's normal operating states and no longer a potential danger for the circuit.