Modeling, Impedance Design, and Efficiency Analysis of Quasi-Z Source Module in Cascaded Multilevel Photovoltaic Power System Academic Article uri icon


  • The quasi-Z source (qZS) cascaded multilevel inverter (CMI) (qZS-CMI) presents attractive advantages in application to photovoltaic (PV) power system. Each PV panel connects to an H-bridge qZS inverter (qZSI) to form a power generation module. The distributed maximum power point tracking and all modules' dc-link peak voltage balance can be achieved. However, it is the same with the conventional CMI that the second-harmonic (2) voltage and current ripples exist in each qZSI module. It is crucial for a qZS-CMI to design the reasonable qZS network parameters to limit the ripples within a desired range. This paper proposes an analytic model to accurately calculate the 2 voltage and current ripples of each qZSI module. A qZS impedance design method based on the built model is proposed to limit the 2 ripples of dc-link voltage and inductor current. Simulated and experimental results through using the designed 1.5-kW prototype validate the proposed analytic model and the design method. Furthermore, this paper analyzes all of the operating states for a qZSI module and calculates the power loss. The measured efficiency from the prototype verifies the theoretical calculation, and the qZS-CMI-based grid-tie PV power system is tested in practical. 1982-2012 IEEE.

published proceedings


author list (cited authors)

  • Sun, D., Ge, B., Yan, X., Bi, D., Zhang, H., Liu, Y., ... Peng, F. Z.

citation count

  • 174

complete list of authors

  • Sun, Dongsen||Ge, Baoming||Yan, Xingyu||Bi, Daqiang||Zhang, Hao||Liu, Yushan||Abu-Rub, Haitham||Ben-Brahim, Lazhar||Peng, Fang Zheng

publication date

  • November 2014