A simple output voltage control scheme for single phase wavelet modulated inverters

Abstract

Wavelet based techniques have been extensively used in various power engineering applications. Recently, wavelet has also been proposed to generate switching signal for single-phase pulse-width-modulated (PWM) dc-ac inverter. The main advantage of the wavelet modulated (WM) scheme is that a single synthesis function, derived using wavelet theory, can be used to generate the switching signal as well as to model the inverter output which is not possible with other modulation techniques. But, unlike other popular PWM schemes e.g. sinusoidal PWM, which offers independent control to both magnitude and frequency of fundamental inverter output voltage, the existing WM scheme can only control the frequency of the fundamental. This paper proposes an improved WM scheme for single-phase H-bridge voltage source inverter. The main emphasis of the research work carried out in this paper is to find a feasible solution to the magnitude control problem for existing WM scheme.

Keywords: PWM inverter; single-phase four pulse voltage source inverter; wavelet inverter; wavelet modulation (WM)