Modular Z-source DC-DC converter based multilevel power conditioning system for PV applications

Abstract

In this paper a power conditioning system based on a modular connection of Z-Source DC-DC converters is presented. The proposed structure presents advantages such as modularity, high voltage gain, and multiple independently controlled input terminals. All these make it suitable for application in PV power plants, especially in cases where large arrays are required in which having the ability of independently following the maximum power point of different array sections is desirable. Moreover it is shown that the proposed structure can continue operation even if faulty modules are present in the power conditioner. Theoretical analysis of the operation of Z-Source DC-DC converter is performed and simulations of a 1 [kW] five module power conditioning system presented.