When motor is in operation, harmonic components are inevitably included. Due to the harmonic components, experimental results of motor performance is different from that obtained from FEA analysis, which assumes there is no time harmonic components. However, time harmonic components should be considered in performance analysis process, since time harmonic has effect such as noise and loss.Time harmonic is generated, depending on inverter switching frequency of PWM control, which occurs independently with spatial harmonics. Thus, time harmonic is not considered in motor design process, requiring additional consideration at later stage.Total harmonic, which is combination of spatial harmonic and time harmonic, has effect on performance of the motor. In detail, when time harmonic components are coupled with spatial harmonic components, some of harmonic components are canceled out, as others are intensified due to interaction. Thus, we present analysis and comparison of motor performance, as the combination of time harmonic components are varied. In this study, 3rd, 5th and 7th harmonic is mainly considered because low order harmonic is fundamental component, that has significant effect on the motor performance. With several combinations of the time harmonic components, FEA is carried out, as results for each cases are analyzed and compared. Based on the analyses, this study shows that combination of time harmonic component has effect on machine performance in different ways. Also, with research on spatial harmonic, relation between time and spatial harmonic is analyzed. To verify the relation, motors with different spatial harmonic components are used, to obtain results that are close to experimental results. As a result, this study suggests that FEA should be carried out considering both time and spatial harmonic components based on the analyzed results, as method proposed in the paper is more accurate than the general method, which assumes ideal three-phase input current.
|Submitters Country||Republic of Korea|