PWM型变频器输出谐波及其抑制技术的仿真研究

PWM transducer output wave form and restrain technology's emulation study

建立了PWM型变频器输出波形的数学模型,得出了n个奇次谐波的幅值与1/4周期内的触发次数m之间的m阶方程组.采用数值法对方程进行求解.用计算机算出可消除m个由低到高奇次谐波的触发角系列,并对结果进行仿真研究,按给出的触发角控制方案进行控制的变频器输出的线电压、相电压和相电流波形.仿真结果表明,所得电流波形已与正弦波接近,经证明是一种有效的谐波抑制技术.图6,表1,参7.

The mathematic model which is the PWM frequency converter's output wave is installed, and come to m order simultaneous equation about the n odd harmonic's amplitude and a quarter of time cycle trigger times(m). The simultaneous equation is solved by the numerical method,and the series angles of trigger can be eliminated m lowtohigh odd harmonics figured out by a computer. At the same time make a simulation research for the result,and come to the wave of the line voltage, the phase voltage and the phase current exported the frequency converter, the frequency converter is controlled by the phase exported the frequency converter, the frequency converter is controlled by the program of trigger control provided in the text. The result of simulation manifests the resulting current wave borders on the sine wave. It is proved this is a efficient restraint technology of the harmonic wave.6figs.,1tab.,7refs.