Z-source networks for power conversion

This paper extends the impedance-source (Z-source) converter/inverter into a broader concept and presents several new impedance-source networks (Z-source networks or Z-networks) for power conversion purpose. The previously presented Z-source network (circuit) consists of two inductors and two capacitors connected in a special arrangement to form a two-port impedance network that can be open-circuited and short-circuited on either end. Based on this unique Z-source network, several power converters/inverters have been presented to overcome the limitations and problems of the traditional voltage-source and current-source converters, to provide the advantageous buck and boost function, and to improve reliability and performance. The Z-source concept is generalized in this paper, which leads to several new Z-networks that can be used in power conversion circuits. Some circuit examples and simulation/experimental results are shown to demonstrate how to apply the Z-source concept and utilize the Z-networks in power converters/inverters.