基于遗传算法的调制载波比优化研究

Optimal Research of Carrier Ratio Based on Genetic Algorithm

本文对脉宽调制(PWM)方式中的分段同步调制方式进行了分析,将正负半周期镜对称,且在半周期内前后周期以π/2为轴线对称的SPWM波表示为傅里叶级数的形式,以载波比N为控制量,开关频率为限定条件,输出电压中谐波分量最小为目标,利用遗传算法求解非线性规划问题的优势,将遗传算法用于在不同频段下最优载波比N的求解问题中,并对所得结果进行了Simulink仿真对比验证,证明了该算法的可行性和有效性。

As one important method of PWM,piecewise synchronous modulation is analyzed in this paper.The method makes the positive half period and the negative half period mirror symmetrical,and expresses the symmetrical SPWM waveform by the form of fourier series in half period,in which the waveform is symmetrical by the axes π/2.Taking the carrier ratio N as its controlled variable,switch frequency as its limitation,and the minimum harmonic in output voltage as its goal,the method can solve the problem of optimal carrier ratio in different frequencies based on genetic algorithm, which has the advantage of solving nonlinear programming problems. At last, simulation results prove that this method is correct and effective.