Single dc source multilevel inverter with changeable gains and levels for low-power loads

Abstract

Different types of multilevel converters have been used to convert DC voltage to AC voltage for different applications. It is, however, desirable for flexible AC output voltage to be created from a single DC source at lower cost. This paper presents a new type of single DC source multilevel inverter which has the ability to create a different number of levels with low rate components. This device is also able boost the magnitude of the output voltage by means of a variable gain with one DC source. The advantages of the multilevel inverter are rapid stepping among levels, and its ability to produce different ranges of levels (seven, nine and eleven) and gains (two, four and eight). The proposed multilevel inverter includes six semiconductor switches, eight diodes, two capacitors and two inductors, making it suitable for low-power applications. A simulation in MATLAB and experimental tests on a prototype setup showed good performance for different modulations, with THD% down to 2.29%, which are meets the IEEE standard (IEEE 519).