Unbalanced magnetic pull induced by the uneven rotor magnetization of permanent magnet synchronous motor

Novák, Miroslav; Košek, Miloslav

doi:10.1109/elektro.2014.6848916

Cited by 10 publications

(4 citation statements)

References 15 publications

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“…The sum of the S/N ratio under each level of each factor is shown in TABLE 8, the relative importance of each factor to the results of η 1 is analyzed. The calculation of the total sum of squares for torque fluctuation is shown as (12): = 35.49 (12) The calculation of the sum of squares for torque fluctuation of each factor (e.g., factor A) is shown as (13): The percentage contribution to torque fluctuation of factor A can be calculated by (14):…”

Section: ) Analysis Of Variance(anova)mentioning

confidence: 99%

“….78 35.49 × 100 = 16.29 (14) Similarly, the sum of squares and the contribution rate for each factor to torque fluctuation and UMP can be calculated and the results are listed in TABLE 9. It can be seen in TABLE 9 and Fig.…”

Section: ) Analysis Of Variance(anova)mentioning

confidence: 99%

“…In [13], it is noted that the change of slot width and pole shape can also reduce the radial electromagnetic force density and then reduce the UMP. In [14], it is considered that the UMP is smaller when the PM magnetization is uniform. The UMP generated by the PM field is reduced by the optimal design of the PM structure, and its arrangement of winding and control method is simpler than the method of optimizing windings.…”

Section: Introductionmentioning

confidence: 99%

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Optimal Design of Permanent Magnet Structure to Reduce Unbalanced Magnetic Pull in Surface-Mounted Permanent-Magnet Motors

Wang

Liu

et al. 2020

IEEE Access

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For the surface-mount permanent magnet synchronous motors (SPMSM) with fractional slot concentrated windings, the winding distribution of per phase under different poles is uneven, which results in unbalanced magnetic pull (UMP) between the stator and rotor. UMP has an important impact on the performance and service life of the motor. In this paper, a new permanent magnet (PM) structure is proposed to reduce UMP and torque fluctuation of the fractional slot SPMSM. Furthermore, a 48p/54s SPMSM is taken as an example, the proposed PM structure is optimized by the Taguchi method which can comprehensively consider the control factors and noise factors. The effects of various variables and process error on UMP, torque fluctuation and robustness of results are analyzed respectively. Finally, the optimized PM structure is obtained, which improves the operation stationarity. INDEX TERMS Fractional slot SPMSM, unbalanced magnetic pull(UMP), torque fluctuation, Taguchi method.

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Section: ) Analysis Of Variance(anova)mentioning

confidence: 99%

Section: ) Analysis Of Variance(anova)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Optimal Design of Permanent Magnet Structure to Reduce Unbalanced Magnetic Pull in Surface-Mounted Permanent-Magnet Motors

Wang

Liu

et al. 2020

IEEE Access

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“…Electrical drives in industrial and automotive applications are manufactured by mass production. Hence, deviations caused by the production such as displacements of the bearing seats, uneven rotor magnetization (Novak and Kosek, 2014), or displacements of the rotational axis of the rotor are unavoidable as described in Smith and Dorrell (1996), Frauman et al (2007) and Dorrell et al (2013). Amongst others, these lead to a rotor eccentricity and causes an unbalanced magnetic pull (UMP), which mechanically burdens the bearings.…”

Section: Introductionmentioning

confidence: 99%

Analysis and determination of mechanical bearing load caused by unbalanced magnetic pull

Ruf

Schröder

Putri

et al. 2016

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

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Purpose – The purpose of this paper is to focus on the mechanical bearing load caused by the unbalanced magnetic pull (UMP), which is studied in detail. The applied approach is based on an analysis of static and dynamic eccentricities at different positions and different amplitudes. The influence of the operating points is calculated to show the effective bearing load for machines operating at different speeds. The decreasing lifetime of the applied bearings is examined and evaluated in detail. Design/methodology/approach – To evaluate the proposed methodology a permanent magnet synchronous machine (PMSM) with buried magnets is used. To consider effects of slotting and saturation, a finite element (FE) model is employed. The Monte Carlo method is used to determine the most likely amplitudes of the eccentricities. Calculating the UMP for all possible operating points using a control strategy for the machine and coupling this results with a drive cycle, determines the effective force acting on the bearing. Findings – It has been shown that the position of the eccentricity has a not significant influence on the behavior of the UMP and may therefore be neglected. The amplitude of the eccentricity vector influences the amplitude of the UMP including all harmonic force components. For technical relevant eccentricities, the influence is approximately linear for the average and the dominant harmonics of the UMP. In most cases, it is sufficient to displace the rotor at an arbitrary position and amplitude. It is sufficient to simulate one type of eccentricity (static or dynamic) with an arbitrary value of displacement (rotor or stator) to evaluate all possible airgap unbalances. Using stochastic simulations of the eccentricity amplitudes enables an a priori design and lifetime estimation of bearings. Originality/value – This paper gives a close insight on the effect of mechanical bearing load caused by rotor eccentricities. The effect of the position of the eccentricity vector, the operational range and a drive cycle are considered. A stochastic simulation and an empirical lifetime model of one bearing gives an example of using this methodological approach.

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Comparison of lateral- and Cylindrical-Stator electrical machines for high-speed direct-drive applications in confined spaces

Tüysüz

Kolar

2016

2016 IEEE Applied Power Electronics Conference and Exposition (APEC)

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Unbalanced magnetic pull induced by the uneven rotor magnetization of permanent magnet synchronous motor

Cited by 10 publications

References 15 publications

Optimal Design of Permanent Magnet Structure to Reduce Unbalanced Magnetic Pull in Surface-Mounted Permanent-Magnet Motors

Optimal Design of Permanent Magnet Structure to Reduce Unbalanced Magnetic Pull in Surface-Mounted Permanent-Magnet Motors

Analysis and determination of mechanical bearing load caused by unbalanced magnetic pull

Comparison of lateral- and Cylindrical-Stator electrical machines for high-speed direct-drive applications in confined spaces

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