摘要:How to eliminate the component of harmonics output voltage of the inverter is a very important factor process of designing an inverter source. It is well known PWM (SPWM,SHET,OSHET)can reduce harmonics effectively. Because of such advantages as fast dynamic response, low frequency and high efficiency, it has been used the every part of the inverter to eliminate harmonics and voltage. But the mentioned above technology is mainly based the assumption that the DC voltage of the inverter is an non-ripple DC source, which is always reached by the method using DC filter capacitor or controlled rectifier bridge in practice. The method of using DC filter capacitor results in low ac power factor. And the controlled rectifier-bridge increases complex of control system. The causes of the harmonic production and the impact on the characteristics of the inverter source on the balanced and unbalanced system are analyzed. a result, a novel method of harmonic elimination of PWM presented. The novel PWM technology simplifies the structure of the inverter mains and greatly decreases or even removes DC filter capacitor. Finally, the superior performance of the inverter source and the new PWM technology is demonstrated through simulation and experimentation. It is obvious that new inverter source and the new PWM technology will wide use in the foreseeable future.