Design and Implementation of a Novel Multilevel DC-AC Inverter

In this paper, a novel multilevel DC-AC inverter is proposed. The proposed multilevel inverter generates seven-level AC output voltage with the appropriate gate signal design. In addition, the low pass filter is used to reduce the total harmonic distortion of the sinusoidal output voltage. The switching losses and the voltage stress across the power devices can be reduced in the proposed multilevel inverter. The operating principles of the proposed inverter and the voltage balancing method of input capacitors are discussed. Finally, a prototype multilevel inverter with an input voltage of 400 V, output voltage of 220 V-rms and output power of 2 kW is implemented. The multilevel inverter is controlled with the sinusoidal pulse-width modulation(SPWM) by TMS320LF2407 digital signal processor (DSP). The experimental results show that the maximum efficiency is 96.9% and the full load efficiency is 94.6%.