基于脉冲多重化的数字SPWM技术

Pulse-multiplied Based Digital SPWM Technique

为有效降低SPWM逆变波形的谐波含量,提出了一种新颖的脉冲多重化数字SPWM逆变控制技术.与SPWM电平多重化技术不同,脉冲多重化是在每个逆变PWM周期,将SPWM脉冲在时间轴上进行的时间多重化.算法直接以数字正弦序列为基础,省去了以往SPWM脉宽计算的大量复杂过程,有效降低了系统的脉宽计算量.对脉冲多重化SP-WM逆变波形频谱进行了理论计算与分析,证明了该技术可以在不增加系统现有开关频率的基础上,进一步降低SPWM逆变波形的谐波含量.最后,给出了该算法的工程实现方法,通过构建实验平台,对该算法进行了实验验证.实验结果证明了该技术的有效性,文中理论分析结果与实际情况完全一致.

To effectively reduce the harmonics of SPWM waveform, this paper presented a new pulse-multi- plied 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 calcultalon 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.