【摘要】 本文针对SVPWM就是鞍形波PWM提法的不严谨性,详细阐述了SAPWM的优化方法,展示了SAPWM的良好效果。指出SVPWM是利用空间电压矢量概念进行PWM的一种方法,并非就是鞍形波,鞍形波是SVPWM的一个特例。SAPWM是在模式优化过程中发现,当正弦调制波的上下包络线对称于横轴时,能获得最优输出特性,其几何、物理意义非常明晰。由于SAPWM调制波波形的固有特点,在相同输出电压条件下,所需的调制深度较SPWM小,使得其在各载波频域中具有更丰富的差频波,但该差频波的幅值较SPWM小,故其总谐波失真和总谐波损耗减小,且其正负序分量产生的脉动转矩在一定程度上相互抵消,有效地抑制了转矩脉动;SAPWM能进一步提高调制深度,有利于提高直流母线电压利用率,从而成为三相逆变器的一种最优调制波。文章在SPWM数学分析的基础上,进一步用傅里叶级数展开法对SAPWM进行了深入的数学分析,逐一论证了SAPWM成为最优调制模式的理论依据。本文的数学分析方法较其他分析方法简捷、明确、易懂,可节省大量的推导工作量。更多还原

【Abstract】 This paper aimed at clarifying the prevalent point of view that the SVPWM is identical to the SAPWM,the optimization method of SAPWM is explained in detail,and the excellent results of SAPWM are easy to be discerned. SVPWM is not SAPWM,it uses the concept of space voltage vector,and SAPWM is a special case of SVPWM. In the pattern optimization process of SAPWM,it is found that when the upper and lower envelope modulation sine waves are symmetrical in the horizontal coordinates,the optimum output characteristics can be obtained,and its meaning is very clear in geometry as well as physical. Owing to the inherent characteristics of SAPWM,when the output voltage is identical,the required depth of modulation is smaller than SPWM,such that there are more difference frequency waves in carrier wave frequency domain. However,compared with SPWM,the amplitude of difference frequency waves is smaller,so the total harmonic distortion and total harmonic loss are reduced to some extent,and the positive and negative sequence components of the cogging torque generated cancel each other,that effectively suppresses the torque pulsation. SAPWM can further raise the modulation depth,and help to improve the DC bus voltage utilization,thus becoming an optimal modulation pattern used in three-phase inverter. On the basis of SPWM mathematical analysis,we made thorough analysis with the use of the Fourier series expansion method for SAPWM,demonstrated the proofs that make SAPWM the optimal modulation pattern. Mathematical analysis of this paper is simpler compared to other analytical methods,clear and easy to understand,and a lot of derivation workload can be saved.更多还原