Abstract

Multilevel converter is a power electronic system that synthesizes a desired output voltage from several levels of dc voltages as inputs. Recently, use of multilevel converters has been extended for medium and high-power applications such as industrial, electric vehicles, renewable energy systems, motor drives, flexible ac transmission systems, and so on. Conventional multilevel inverter topologies when used for higher levels require large number of power electronic components. The proposed topology uses a novel cascade structure with reduced number of switches. The switching pulses for the inverter switches are generated by sinusoidal pulse width modulation using FPGA. Using the proposed topology a 25 level inverter can be realized with reduced number of switches. The output waveform is near sinusoidal. Compared with conventional multilevel inverters, it requires less number of components to achieve same number of output levels. Overall THD is very low and thus the quality of output waveform is improved. Due to the use of fewer switches, optimized circuit layout and packaging is possible. Thus less cost is required to implement the proposed inverter.