一种新的有源滤波器优化特定消谐PWM技术

影响有源滤波器消谐特性的重要因素是充分减小特定消谐PWM波形剩余谐波含量及其改善剩余谐波的频谱分布。特定消谐PWM波形的剩余谐波含量较大，谐波频谱分布差是它固有的缺点。为了克服特定消谐PWM技术本身的缺点，提出了一种新的优化特定消谐PWM开关角的优化解法。利用独特的优化技术将剩余谐波的第一波峰向后推移，改善输出波形的频谱分布，综合抑制有源滤波器的电流畸变率，提高装置的效率。以M＝13为例说明其优化原理，最后通过计算机仿真验证了理论的正确性。

A NOVEL SELECTIVE HARMONIC ELIMINATION PWM TECHNIQUE FOR ACTIVE POWER FILTER

An important factor which influences the harmonic elimination characteristic of active power filtermainly lies on how to sufficiently reduce the surplus harmonic content in the waveform of selective harmonic elimination PWM and how to improve the spectrum distribution of surplus harmonics. The inherent drawback of selective harmonicelimination PWM is the higher content of its surplus harmonics and bad spectrum distribution. To overcome the drawback of selective harmonic elimination PWM technique itself, a novel optimal solution method which optimizes the switching angle of selective harmonic elimination PWM is proposed. Using the distinct optimization technique the first crest of the surplus harmonics is moved backwards to improve the spectrumdistribution of output waveform, to comprehensively reducethe current distortion rate of active power filter and to increase the efficiency of this equipment. The optimizing principle is explained by the example M=13, and the correctness of thepresented method is validated by computer simulation.