摘  要：借助有限元法对PWM型逆变器供电的异步电机进行了损耗分析。由于逆变器整流方式的不同，产生了不同的电压波形，文中结合有限元法和异步电机的模型，对异步电机由于谐波作用产生的损耗进行了分析。通过把磁场分布分割为若干谐波分量，以找出谐波磁场的作用和主要的损耗因素。由此证明了转子表面的损耗大多由谐波产生。高次谐波使电动机产生脉动转矩,使输出机械特性变差,同时降低了传动系统运行的稳定性,并由于谐波损耗的产生,使电动机附加损耗增加,从而降低传动系统的能量转换效率。所以对异步电机必须考虑高次谐波的影响。
关键词：异步电机；PWM逆变器；谐波；铁芯损耗；铜损耗；有限元法（FEM）

Abstract: The losses of asyhchrounous machine driven by PWM inverters were analyzed using the finite element method considering the carrier harmonics. The calculated results were compared with the experimental ones. To consider the effect of the carrier, the theoretical voltage waveform due to the switching pattern of the inverter was given to the analysis by coupling the primary voltage equation and the finite element formulation. The method to decompose the electromagnetic field distribution into time-harmonic components was introduced in order to investigate the effects of the harmonic fields separately and to specify the main loss factors. It was clarified that the rotor surface loss especially increases due to the harmonics and that the accuracy of the calculated characteristics of the machine was improved by considering the harmonics.
Key words: asyhchrounous machine； PWM inverter; harmonics; iron loss; copper loss; finite element method