A generalised wavelet modulation scheme for single-phase inverters

Abstract

More recently, a completely different and a promising PWM switching method, based on wavelet modulation (WM) has been reported for single phase inverters. The WM scheme has been tested with single-phase inverters; higher magnitudes of fundamental components and lower harmonic contents than those from the conventional PWM and Random PWM inverters are reported. However, a major problem with WM scheme, in its present form, is that it does not provide complete control on inverter output voltage. The existing WM scheme, in its present form, cannot fully control inverter output voltage magnitude. Contrary to the existing WM method, the method proposed in this paper, termed as generalised wavelet modulation (GWM) scheme is capable of producing wide range of variable magnitude and frequency fundamental voltages at inverter output without indulging any extra computational burden. The proposed GWM scheme of four pulse single phase inverter presented in the paper is implemented using a MATLAB code, and is finally converted to an equivalent SIMULINK block. Extensive simulations have been carried out on single phase voltage source inverter using the developed SIMULINK block to analyse the performance of the proposed scheme at different switching frequencies and for a wide range of inverters output voltage magnitudes.