变频电源特定消谐技术中非线性方程组解法的研究

Investigation of Solution to the Non liner Equation Set up of SHET in Converters

讨论了变频电源特定消谐（ＳＨＥ：ＳｅｌｅｃｔｉｖｅＨａｒ－ｍｏｎｉｃＥｌｉｍｉｎａｔｉｏｎ）技术与载波ＳＰＷＭ技术相比的特点；以最常用的三相半桥电压型逆变电源为分析对象，研究了ＳＨＥ技术的数学模型及其非线性方程组用牛顿迭代法求解的步骤，总结出了非线性方程组中开关角两组解给初值的规律，给出了开关角两组解随基波幅值变化的轨迹；设计了一种新颖、简单实用的ＳＨＥ技术的硬件电路，通过实验结果验证了所给出的两组解的正确性，从而为变频电源ＳＨＥ技术的实用化奠定了基础。

In this paper advantages of selective harmonic elimination technique(SHET) comparing with SPWM technique are discussed,we use the most general three phase half bridge voltage source converter as analytical object,research the mathematical model of SHET and the step of solving its non linear equation set up using the Newton interation method;summarize the regularity of selecting initial values of two groups of solutions to switching angles in non liner equation set up provide the tracks of two groups of solutions to switching angles with changing amplitude of fundmental harmonic;design a kind of original,simple and practical hardware circuit using SHET.The accuracy of two groups of solutions is verified by experimental results,so lay the group work of application of SHET in converters.