| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inverter that outputs AC power with reduced harmonic distortion. <P>SOLUTION: A control section uses a plurality of gradation voltages comprising supply voltages from a plurality of DC power supplies with different voltages and a potential difference between every two supply voltages to generate a quasi-sinusoidal wave. Specifically, the control section generates the quasi-sinusoidal wave by generating, in every time range in which a sinusoidal voltage crosses two gradation voltages, a PWM signal having a low level and a high level at one gradation voltage and the other gradation voltage, respectively. For the decision of the switching timing of the PWM signal, a triangular wave having a low level and a high level at one gradation voltage and the other gradation voltage, respectively, is generated in the time range in which the sinusoidal voltage crosses two gradation voltages, and intersections of the triangular wave with the sinusoidal wave are used. <P>COPYRIGHT: (C)2013,JPO&INPIT |
