Computationally Efficient Method for Calculating Radial Electromagnetic Force of Induction Motor Using Stepping Time-Harmonic Finite Element Analysis

초록

Induction motors (IMs) have long been widely used as industrial motors. Although the required characteristics of IMs may vary depending on the application, reducing noise, vibration, and harshness (NVH) is a common requirement across all fields. As demonstrated in multiple studies, the radial electromagnetic force is the most influential factor affecting the vibration characteristics of electric motors. Therefore, analyzing the radial electromagnetic force is essential for enhancing the vibration performance of electric motors. However, finite element analysis (FEA) of IMs requires considerable computation time, as it must be conducted as a transient analysis. In this article, stepping time-harmonic FEA is proposed for the fast calculation of the radial electromagnetic force in IMs. Unlike conventional time-harmonic FEA, the proposed method incorporates mechanical and electrical rotation of the IM in the analysis. The proposed method was used to obtain the air-gap flux density over one electrical period, and the radial electromagnetic force density was calculated using Maxwell stress tensor (MST). The spatial and temporal orders of the radial electromagnetic force density were analyzed using 2-D fast Fourier transform (FFT), and good agreement was confirmed between the proposed method and the 2-D transient FEA. The proposed method significantly reduces the computation time required for calculating the radial electromagnetic force density compared to 2-D transient FEA. Therefore, it was confirmed that the proposed method enables rapid computation of the radial electromagnetic force density in the IM while ensuring a high level of accuracy.

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