ABSTRACT:
In the microgrid system, the distributed energy
resource (DER)-based single-phase inverter is usually adopted. In order to
reduce conversion losses, the key is to save costs and size by removing any
kind of transformer as well as reducing the power devices. The objective of
this letter is to study a novel five-level multi string inverter topology for
DERs-based dc/ac conversion system. In this study, a high step-up converter is
introduced as a front-end stage to improve the conversion efficiency of
conventional boost converters and to stabilize the output dc voltage of various
DERs such as photovoltaic and fuel cell modules for use with the simplified multilevel
inverter. The simplified multilevel inverter requires only six active switches
instead of the eight required in the conventional cascaded H-bridge multilevel
inverter. In addition, two active switches are operated at the line frequency.
The studied multi string inverter topology offers strong advantages such as
improved output waveforms, smaller filter size, and lower electromagnetic
interference and total harmonics distortion. Simulation and experimental results
show the effectiveness of the proposed solution.
KEYWORDS:
1.
DC/AC power
conversion
2.
Multilevel
inverter
SOFTWARE: MATLAB/SIMULINK
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