线性组合采样法SPWM新技术

针对不对称规则采样法PWM采样次数多、占用微处理器资源大的问题,提出了一种线性组合采样的新方法。该方法通过对三角载波顶点位置的调制波采样的线性组合获得载波周期内的另一采样值,使采样次数比不对称规则采样法减少一半。谐波计算结果表明新方法的PWM电压THD指标达到了不对称规则采样法PWM相同水平,并保持电压基波分量与调制度之间的线性关系。新方法的PWM算法简单,适于采用微处理器或DSP实时、在线计算。仿真结果证实了新方法的有效性。

A novel linear combination sampling SPWM technique

The conventional asymmetric regular sampled PWM requires a large sampling number to be collected, and consequently consumes a large portion of microprocessor's resources. This paper presents a novel linear combination sampling technique to address the above-mentioned issue. Through applying the linear combination sampling on the triangular carrier-wave peaks, the technique obtained another sample of the sinusoidal modulating wave from every carrier wave cycle. As a result, it reduced the sampling number by half. Harmonic calculation had validated that the minimization of total harmonic voltage distortion (THD) of the PWM voltage in the new technique was in agreement with that in the asymmetric regular sampling method, and it also maintained the linear relationship between the PWM fundamental waveform and the modulation index M. The software algorithm in the new technique was much simpler to generate PWM, and therefore, it will be applicable to real-time on-line microprocessor or DSP generation. The simulation results had validated the new technique.