Pulse-multiplied Based Digital SPWM Technique

To effectively reduce the harmonics of SPWM waveform,this paper presented a new pulse-multiplied digital SPWM technique for sine inverter power.Unlike the multilevel inverter technique,the pulse-multiplied SPWM technique is multiplied in the time axis of SPWM signal in each PWM period.This algorithm is directly based on the digital sine sequence signal.Therefore,lots of complicated processes of pulse width calcultaion has been omitted,and the digital SPWM algorithm has been effectively simplified.Through theoretical deduction and analysis of the frequence spectrum of pulse-multiplied SPWM signal,it has been proved that this technique can effectively reduce the harmonics of the SPWM signal without increasing the switching frequence of the sine inverter power system.Finally,a realization method based on DSP technique has been provided.To prove the theory of the technique,an experimental platform was constructed. The experiment result has proved the effectiveness of the pulse-multiplied digital technique,which is exactly in agreement with the theoretic analysis.