Analytical calculation of vibrations of electromagnetic origin in electrical machines. (1st January 2018)

• Record Type: Journal Article
• Authors: McCloskey, Alex; Arrasate, Xabier; Hernández, Xabier; Gómez, Iratxo; Almandoz, Gaizka
• Is Part Of: Mechanical systems and signal processing. Volume 98(2017)
• Page Start: 557
• Page End: 569
• Publication Date: 2018-01-01
• Subjects: Electrical machines -- Vibration -- Analytical calculations -- Stator -- Electromagnetic forces; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2017.04.050
• Languages: English
• ISSNs: 0888-3270

Abstract

Highlights: An analytical vibration calculation model is developed for electrical machines. Tooth geometry and orthotropic properties are considered by the proposed model. Accurate and much quicker natural frequencies calculation compared to FEM. Fast vibration response estimation shows reasonable agreement with experimental data. Optimised machine designs can be achieved applying the proposed calculation tool. Abstract: Electrical motors are widely used and are often required to satisfy comfort specifications. Thus, vibration response estimations are necessary to reach optimum machine designs. This work presents an improved analytical model to calculate vibration response of an electrical machine. The stator and windings are modelled as a double circular cylindrical shell. As the stator is a laminated structure, orthotropic properties are applied to it. The values of those material properties are calculated according to the characteristics of the motor and the known material properties taken from previous works. Therefore, the model proposed takes into account the axial direction, so that length is considered, and also the contribution of windings, which differs from one machine to another. These aspects make the model valuable for a wide range of electrical motor types. In order to validate the analytical calculation, natural frequencies are calculated and compared to those obtained by Finite Element Method (FEM), giving relative errors below 10% for several circumferential and axial mode order combinations. It is also validated the analytical vibration calculation with acceleration measurements in a real machine. The comparison shows good agreement for the proposed model, being the most important frequency components in the same magnitude order. A simplified two dimensional model is also applied and the results obtained are not so satisfactory.