Cogging Torque and Unbalanced Magnetic Force Prediction in PM Machines With Axial-Varying Eccentricity by Superposition Method

Li, Y. X.

doi:10.1109/tmag.2017.2700522

Cited by 17 publications

(12 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The comprehensive eccentricity of the investigated cross section is: The air gap length of mixed inclined eccentricity is further investigated in the following paragraphs. The general case of air gap changes along the axial direction can be considered as mixed inclined eccentricity [38,39]. As Figure 5 demonstrates, it is assumed that the stator is stationary and the midpoint of rotor in the axial direction is selected to be the origin of the coordinates.…”

Section: Inclined Eccentricitymentioning

confidence: 99%

Review of Electromagnetic Vibration in Electrical Machines

Han

Chu

2018

Energies

View full text Add to dashboard Cite

Electrical machines are important devices that convert electric energy into mechanical work and are widely used in industry and people's life. Undesired vibrations are harmful to their safe operation. Reviews from the viewpoint of fault diagnosis have been conducted, while summaries from the perspective of dynamics is rare. This review provides systematic research outlines of this field, which can help a majority of scholars grasp the ongoing progress and conduct further investigations. This review mainly generalizes publications in the past decades about the dynamics and vibration of electrical machines. First the sources of electromagnetic vibration in electrical machines are presented, which include mechanical and electromagnetic factors. Different types of air gap eccentricity are introduced and modeled. The analytical methods and numerical methods for calculating the electromagnetic force are summarized and explained in detail. The exact subdomain analysis, magnetic equivalent circuit, Maxwell stress tensor, winding function approach, conformal mapping method, virtual work principle and finite element analysis are presented. The effects of magnetic saturation, slot and pole combination and load are discussed. Then typical characteristics of electromagnetic vibration are illustrated. Finally, the experimental studies are summarized and the authors give their thoughts about the research trends.Energies 2018, 11, 1779 2 of 33 vibration mechanism can be helpful for the design of electrical machines. Therefore, the study of the electromagnetic vibration of electrical machines has practical significance.Electromagnetic vibrations are usually generated by the distorted air-gap field of an eccentric rotor in electrical machines. The uneven air-gap is directly related to the eccentricity, which is common in rotating electrical machines. Eccentricity can be caused by several reasons, such as relative misalignment of the rotor and stator in the fixing stage, misalignment of the load axis and rotor shaft, elliptical stator inner cross section, wrong placement or rubbing of ball bearings, mechanical resonance, and unbalanced loads [1,2]. Eccentricities can be further subdivided into two categories: circumferential unequal air gaps and axial unequal air gaps. The former can be grouped into static eccentricity and dynamic eccentricity. In the case of static eccentricity, the rotor rotates around its own geometric axis, which is not the geometric axis of the stator. In the case of dynamic eccentricity, the rotor is not concentric and rotates around the geometric axis of the stator. In reality, both static eccentricity and dynamic eccentricity tend to coexist. An inherent static eccentricity exists, even in newly manufactured machines, due to the build-up of tolerances during the manufacturing and assembly procedure, as has been reported in [3]. Unequal air gaps cause unbalanced magnetic forces (UMFs) [4] on the rotor, which lead to mechanical stress on some part of the shaft and bearing. After prolonged operation, these fac...

show abstract

Section: Inclined Eccentricitymentioning

confidence: 99%

Review of Electromagnetic Vibration in Electrical Machines

Han

Chu

2018

Energies

View full text Add to dashboard Cite

show abstract

“…The common range of φ is [0, 2π], while the scope of inverse trigonometric functions is [0, π]. The following extension is conducted [33]:…”

Section: A Electromagnetic Vibrationmentioning

confidence: 99%

Vibration Detection and Experiment of PMSM High Speed Grinding Motorized Spindle Based on Frequency Domain Technology

Cheng

Gao

2019

Measurement Science Review

View full text Add to dashboard Cite

The spindle vibrations of the high-speed grinding motorized spindle largely determine the machining quality and precision. In order to accurately predict the spindle vibrations of the PMSM high-speed grinding motorized spindle, the vibration causes are explored and analyzed. The radial vibration, inclined vibration, and axial vibration model are established. The experimental modal analysis method is proposed to analyze the dynamic response of the spindle and to identify the modal parameters of the spindle structure. Thereafter, the frequency response function (FRF) is calculated by self-power spectrum and cross-power spectrum. It is transformed into the vibration spectrum analysis of the spindle. The least-square method is used to fit the radial trajectory of the spindle. This paper aims to propose double standard spheres for 5-DOF spindle vibrations used to detect the spindle vibrations. In the experiment, the method proposed in this paper can effectively and accurately determine the causes of the spindle vibrations. The spectrum analysis and the trajectory are common tools in the spindle vibration detection.

show abstract

“…Low-speed and high-torque direct-drive permanent magnet (PM) motor can realise the direct contact between power and load, cancel the mechanical transmission equipment such as reducer, shorten the transmission link to the greatest extent, which will maximise the energy transfer efficiency and has been widely used [1,2]. Because the overall dimensions of this type of motor are usually large, the problems of machining errors, material deformation, and assembly errors are inevitable [3]. The manufacture tolerance or failure includes the deviation of magnet properties, dimension and position, the deviation of stator lamination dimension and properties, and rotor eccentricity [4,5].…”

Section: Introductionmentioning

confidence: 99%

Research on rotor unbalance magnetic pull compensation method based on modular winding d‐axis current injection

Zhang

Guo

2021

IET Electric Power Appl

View full text Add to dashboard Cite

Due to the dual air-gap topology of the direct-drive permanent magnet motor with inner enhance force (IEF-DDPMM), the radial EM exciting force generated in the inner and outer air gaps when the rotor is eccentric will act on the same rotor, and the unbalanced magnetic pull (UMP) on the rotor will reduce the fatigue life of the rotor structure and bring many problems such as vibration and noise. Therefore, the rotor UMP compensation method of IEF-DDPMM based on modular winding d-axis current injection is proposed to suppress the harm caused by eccentricity. The expression of electromagnetic (EM) exciting force considering the cogging effect and current time harmonic without rotor eccentricity faults is derived by the analytical method. Also, the EM exciting force newly introduced due to the rotor eccentricity is analysed. The effects of different eccentricity types on torque characteristics, the fatigue life of the rotor structure and stator vibration of IEF-DDPMM are compared and analysed by the FEM. Finally, the IEF-DDPMM rotor eccentricity models are optimised based on the method. The performance of the motor before and after rotor UMP compensation is evaluated by FEM. The results show that the proposed method is correct and effective.

show abstract

Cogging Torque and Unbalanced Magnetic Force Prediction in PM Machines With Axial-Varying Eccentricity by Superposition Method

Cited by 17 publications

References 6 publications

Review of Electromagnetic Vibration in Electrical Machines

Review of Electromagnetic Vibration in Electrical Machines

Vibration Detection and Experiment of PMSM High Speed Grinding Motorized Spindle Based on Frequency Domain Technology

Research on rotor unbalance magnetic pull compensation method based on modular winding d‐axis current injection

Contact Info

Product

Resources

About