Wavelet Modulation for Neutral Point Clamped Multilevel Inverters

Abstract — This paper implements a new type of modulation known as Wavelet Modulation (WM) based on non-uniform sampling and wavelet theory in a multilevel neutral-point clamped inverter. The proposed scheme is compared with other modulation techniques such as Sinusoidal Pulse Width Modulation (SPWM) and Square-wave Pulse Width Modulation (SQPWM). Simulation results show that the WM technique produces smoother current output, better output voltage, and lesser Total Harmonic Distortion (THD) as compared with the other modulation techniques. Keywords—modulation, neutral-point clamped multilevel inverter, THD, wavelets, wavelet modulation. I