Digital scalar pulse-width modulation: A simple approach to introduce non-sinusoidal modulating waveforms

The digital scaler pulse-width modulation (DSPWM) gathers the characteristi cs of simplicity of implementation found in the regular sampling with the f lexibility of manipulation of the switching patterns in the space vector mo dulation (SVPWM), This paper establishes a correlation between the SVPWM an d DSPWM techniques. It also shows how to make the DSPWM strategy equivalent to the SVPWM technique without loosing its simplicity of implementation. B y using such equivalence concept a microprocessor-based scheme, which uses standard timer circuits and a simple software algorithm, is proposed to imp lement the DSPWM technique. The introduction of the "distribution ratio" in this technique, allows the development of a systematic approach for implem enting of either conventional or any modified vector strategies without cha nging the modulator scheme. This corresponds to generate any attractive non sinusoidal modulating signals (NSMS) in the carrier-based modulation techni ques. Furthermore, the simple digital blocks can be easily implemented as a n specialized integrated circuit. Simulated and experimental results demons trate the validity of the proposed methods.