Increasing the efficiency of a drone motor by arranging magnetic sheets to windings

Sato, Masaru; Nirei, Masami; Yamanaka, Yuichiro; Suzuki, Takahiro; Bu, Yinggang; Matsumoto, Tsutomu

doi:10.1016/j.egyr.2019.11.100

Cited by 15 publications

(8 citation statements)

References 10 publications

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“…Referring to the analysis of Equations ( 3)-( 5), it can be observed that the polar arc coefficient has a great influence on the fundamental air gap flux density, which affects the eddy current loss value of PM, especially at high frequency. Therefore, the original design will produce a large loss at the PM [18][19][20][21].…”

Section: Polar Arc Coefficient and Permanent Magnet Lossmentioning

confidence: 99%

Investigation of Eddy Current Loss and Structure Design with Magnetic-Thermal Coupling for Toothless BLDC High-Speed PM Motor

Zhao

et al. 2022

Machines

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Brushless direct current (BLDC) permanent magnet (PM) synchronous motors are in high demand for ventilator applications owing to their high speed, high efficiency, and other significant features. However, it has become an important problem in eddy current loss calculations with high-speed motors, which leads to low motor (ventilator) life and PM demagnetization. This paper focuses on the eddy current loss calculation and the structure improvement design for the two-pole 90 W, 47,000 r/min toothless BLDC motor. First, the influencing factors of eddy current loss are comprehensively investigated, and a multiparameter improvement methodology is proposed accordingly. Second, by finite element analysis (FEA), the effective winding length ratio and the number of parallel wires were mainly researched for the winding, and the influence on the eddy current loss and the efficiency was determined, providing a reference for BLDC high-speed motors. This study has resulted in a 34.75% reduction in the winding losses, and a 4.6% increase in the efficiency of the improved model compared with the original design. Third, the new rotor structure is proposed, saving PM volume 15% more than original. THD of gap flux density is decreased 20.97%; the eddy current loss in the new rotor is decreased 22% more than original. Furthermore, by coupling simulation of the magnetic–thermal field, the maximum temperature of winding of the improved model is 13.4% lower than that of the original model at the thermal steady state. Finally, the electromagnetic and thermal properties simulation results were verified by testing the prototype. It is of great significance to the structure design and efficiency improvement of the BLDC high-speed motor.

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Section: Polar Arc Coefficient and Permanent Magnet Lossmentioning

confidence: 99%

Investigation of Eddy Current Loss and Structure Design with Magnetic-Thermal Coupling for Toothless BLDC High-Speed PM Motor

Zhao

et al. 2022

Machines

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“…The waveform distortion is caused by leakage flux that occurs in the parts of the permanent magnet, which are enclosed by the top teeth of the rotor slots. Leakage flux increases eddy current, thus decreases machine efficiency [23].…”

Section: A Magnetic Characteristicsmentioning

confidence: 99%

Characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications

Irasari¹,

Wirtayasa²,

Widiyanto³

et al. 2021

J. Mechatron. Electr. Power Veh. Technol.

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Permanent magnet motors (PMMs) are widely used in electric vehicles because of their benefits. Based on the permanent magnet topologies on the rotor, PMMs are classified into three types: surface mounted PMM, inset PMM, and interior PMM. This paper discusses a comparison of the characteristics of interior and inset types of PMMs for electric vehicle applications. The study aims to find out the effect of the rotor construction on the magnetic characteristics, torque-speed characteristics, and cogging torque. Simulations were carried out analytically and numerically using the FEMM 4.2 software. The simulation results at the base speed show that the interior PMM generates a higher torque but with a lower rotation, namely 56.47 Nm and 3162 rpm, respectively, while the inset PMM produces higher rotation 4200 rpm but lower output torque of 46.01 Nm. However, with a higher saliency ratio, the interior PMM produces higher maximum torque and speed at both constant torque and field weakening regions than the PMM inset, which is 92.87 Nm and 6310 rpm, consecutively. In terms of cogging torque, the interior PMM raises it slightly higher (2.90 Nm) than the inset PMM (1.93 Nm). The results conclude that, in general, the interior PMM shows better performance in all studied regions and is preferable for electric vehicle applications.

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“…The composite ring formed of a resin material mixed with magnetic powder was mounted on a stator, and windings were embedded with a magnetic material in the ring motor. The magnetic composite material was manufactured by mixing magnetic powder and resin [35,36]. Magnetic composite materials have a higher relative permeability than air, and their relative permeability is significantly smaller than that of electrical steel sheets.…”

Section: Structurementioning

confidence: 99%

“…The magnetic composite material was manufactured by mixing, stirring, and firing iron amorphous ball powder with an average particle size of 2.6 µm and the impregnated adhesive V-2000 at a volume ratio of 64 vol.% [36]. The magnetic properties were evaluated with a toroidal core made of a magnetic composite material.…”

Section: Magntic Ring Characteristicsmentioning

confidence: 99%

Reducing Rotor Temperature Rise in Concentrated Winding Motor by Using Magnetic Powder Mixed Resin Ring

et al. 2020

Self Cite

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The demand for high-speed servomotors is increasing, and minimal losses in both high-speed and high-torque regions are required. Copper loss reduction in permanent magnet motors can be achieved by configuring concentrated winding, but there are more spatial harmonics compared with distributed winding. At high-speed rotation, the eddy current loss of the rotor increases, and efficiency tends to decrease. Therefore, we propose a motor in which a composite ring made from resin material mixed with magnetic powder is mounted on the stator to suppress spatial harmonics. This paper describes three characteristic motor types, namely, open-slot motors, composite-ring motors, and closed-slot motors. Spatial harmonics are reduced significantly in composite-ring motors, and rotor eddy current loss is reduced by more than 50% compared with open-slot motors. Thermal analysis suggests that the saturation temperature rise value is reduced by more than 30 K. The use of a composite ring is effective in reducing magnet eddy current loss during high-speed rotation. Conversely, the torque characteristics in the closed-slot motor are greatly reduced as well as the efficiency. Magnetic circuits and simulations show that on electrical steel sheets with high relative permeability, the ring significantly reduces the torque flux passing through the stator, thus reducing the torque constant. To achieve reduced eddy current loss during high-speed rotation while ensuring torque characteristics with the composite ring, it is necessary to set the relative permeability and thickness of the composite ring according to motor specifications.

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Increasing the efficiency of a drone motor by arranging magnetic sheets to windings

Cited by 15 publications

References 10 publications

Investigation of Eddy Current Loss and Structure Design with Magnetic-Thermal Coupling for Toothless BLDC High-Speed PM Motor

Investigation of Eddy Current Loss and Structure Design with Magnetic-Thermal Coupling for Toothless BLDC High-Speed PM Motor

Characteristics analysis of interior and inset type permanent magnet motors for electric vehicle applications

Reducing Rotor Temperature Rise in Concentrated Winding Motor by Using Magnetic Powder Mixed Resin Ring

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