Design and Analysis of a Permanent-Magnet-Assisted Switched Reluctance Motor

Hongsik Hwang,Jin Hur,Cheewoo Lee 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.6

A permanent-magnet-assisted switched reluctance motor (SRM) having small excitation poles, where phase coils are concentrically wound on the poles and thin permanent magnets are inserted inside the poles, is proposed in this paper. The insertion of permanent magnets into the stator excitation poles has a significant influence on positive torque improvement leading to a boost in efficiency. Three key design parameters such as the thickness of permanent magnets, space between two adjacent permanent magnets, and the width of stator excitation poles are determined during a design procedure in terms of the enhancement of positive torque. Step-by-step design modification and a comparison between the proposed permanent-magnet-assisted SRM and no-permanent-magnet SRM have been conducted by means of static torque comparison along with dynamic performance. The first prototype from steel laminations up to its physical assembly has been constructed.

영구자석 비선형 자기특성을 고려한 회전자 타입에 따른 모터 특성 분석

박민로(Min-Ro Park),서갑호(Kap-Ho Seo),황성우(Sung-Woo Hwang),임명섭(Myung-Seop Lim) 한국자기학회 2021 韓國磁氣學會誌 Vol.31 No.3

The permanent magnet is an important component that determines the performance and cost of a synchronous motor. Also, the characteristic of the permanent magnet is a major factor in determining the performance of the electric motor. Therefore, to improve the performance of the permanent magnet synchronous motor and reduce the material cost, the permanent magnets having various characteristics are being developed. However, the magnetic properties of permanent magnets have nonlinearity. Therefore, this paper proposes a method to calculate the operating point of a permanent magnet by considering not only the nonlinear magnetic properties of the electrical steel sheet but also the nonlinear properties of the permanent magnet and analyze the characteristics of the electric motor based on this proposed method. Through this, the characteristics of the permanent magnet synchronous motor are analyzed according to the rotor type and the design direction for each type is suggested.

Magnetic Field Calculation and Dynamics Simulation of a Permanent Magnetic Hybrid Driven 3-DOF Motor

Zheng Li,Wei He,Lingqi Liu,Qunjing Wang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.2

In view of the poor precision of existing defl ection movement control and low speed of multi-degree-of-freedom motor rotation speed, a novel type of permanent magnet type 3-DOF hybrid driven motor is proposed, the motor contains two part named lateral rotation module and internal defl ection modules. By using Halbach permanent magnet array, the magnetic fi eld shielding and optimization of two modules inside and outside the motor are realized, and the magnetic fi eld characteristics of the motor are improved. Using the analytical and fi nite element methods, the magnetic fi eld characteristics and distribution of the permanent magnet of the motor are analyzed and proved. The dynamic model of the motor is established and analyzed. The back EMF of the physical motor is tested and verifi es the accuracy of the fi nite element model. The results provide a new theoretical basis for the follow-up optimization of this kind of motors.

Fault Diagnosis Method of Permanent Magnet Synchronous Motor for Electrical Vehicle

Jin-Hyung Yoo,Tae-Uk Jung 한국자기학회 2016 Journal of Magnetics Vol.21 No.3

The permanent magnet synchronous motor has high efficiency driving performance and high power density output characteristics compared with other motors. In addition, it has good regenerative operation characteristics during braking and deceleration driving condition. For this reason, permanent magnet synchronous motor is generally applied as a power train motor for electrical vehicle. In permanent magnet synchronous motor, the most probable causes of fault are demagnetization of rotor’s permanent magnet and short of stator winding turn. Therefore, the demagnetization fault of permanent magnet and turn fault of stator winding should be detected quickly to reduce the risk of accident and to prevent the progress of breakdown of power train system. In this paper, the fault diagnosis method using high frequency low voltage injection was suggested to diagnose the demagnetization fault of rotor permanent magnet and the turn fault of stator winding. The proposed fault diagnosis method can be used to check the faults of permanent magnet synchronous motor during system check-up process at vehicle starting and idling stop mode. The feasibility and usefulness of the proposed method were verified by the finite element analysis.

Study on the Influence of Magnetic Circuit Saturation on Suspension Performance of Bearingless Permanent Magnet Synchronous Motor

Liu Liming,Qiu Hongbo 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.4

Bearingless permanent magnet synchronous motors can rely on the radial electromagnetic force generated by magnetic fi eld coupling to achieve active suspension. However, the coupling between magnetic fi elds may lead to the saturation of the magnetic circuit, which aff ects the stability of motor suspension force and is one of the key problems to be solved for bearingless motors. In order to investigate the eff ect of magnetic circuit saturation on the suspension performance, fi rstly, the equation of the radial suspension force is derived by combining the infl uence of the magnetic circuit saturation on the parameters of the motor. The relationship of the magnetic circuit saturation on the stable and fl uctuating components of the radial suspension force is obtained, and the fl uctuation mechanism of the suspension force under the saturation state is revealed. Secondly, the radial suspension force in diff erent saturation states of the magnetic circuit is calculated by fi nite element calculation method. Combining the eff ect of magnetic fl ux density on the magnetic permeability, the variation of the magnitude and fl uctuating of the suspension force with the magnetic fi eld in diff erent magnetic circuit saturation states is given. Finally, the accuracy of the analytical and fi nite element calculations is demonstrated experimentally.

Comparative Study on Novel Dual Stator Radial Flux and Axial Flux Permanent Magnet Motors With Ferrite Magnets for Traction Application

Wenliang Zhao,Lipo, Thomas A.,Byung-Il Kwon IEEE 2014 IEEE transactions on magnetics Vol.50 No.11

<P>This paper proposes two novel traction motors with ferrite magnets for hybrid electric vehicles (HEVs), which have competitive torque density and efficiency as well as operating range with respect to a referenced rare earth magnet motor employed in the third-generation Toyota Prius, a commercialized HEV. The two proposed traction motors, named as dual stator radial flux permanent magnet motor (DSRFPMM) and dual stator axial flux permanent magnet motor (DSAFPMM), adopt the same design concept, which incorporates the unaligned arrangement of two stators together with the use of spoke-type magnet array and phase-group concentrated-coil windings for the purpose of increasing torque density and reducing torque ripple. A finite element method is utilized for predicting the main characteristics, such as back electromotive force, cogging torque, electromagnetic torque, iron loss, and efficiency in both of the proposed motors. Moreover, a comparative study between the proposed DSRFPMM and DSAFPMM is performed under the same operating condition. As a result, it is demonstrated that both of the proposed ferrite permanent magnet motors could be good alternatives for traction application, replacing the rare earth magnet motors.</P>

Multiphysical Design and Optimization of High-Speed Permanent Magnet Synchronous Motor with Sinusoidal Segmented Permanent Magnet Structure

Liu Chengcheng,Zhang Hongming,Wang Shaoheng,Wang Youhua,Lei Gang,Zhu Jianguo 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

High speed permanent magnet synchronous motor (HSPMSM) is an important driving motor for electric vehicles. Compared with the electric motor operated under normal speed, it is critical to reduce the torque ripple, vibration, and noise of the HSPMSM. Furthermore, The air-gap fux density total harmonic distortion and electromotive force total harmonic distortion determine by torque performance and vibration noise. This article uses analytical methods to analyze the infuence of permanent magnet sinusoidal segmentation (PMS) on the electromagnetic performance of surface-mounted HSPMSM. The fnite element method is used to calculate the infuence of diferent permanent magnet segmentation numbers, diferent adjacent permanent magnet decreasing thickness, and diferent center PM width on the electromagnetic performance of permanent magnet sinusoidal segmented surface-mounted high-speed permanent magnet synchronous motor (M2). Comparing the efectiveness of PMS in surface-mounted HSPMSM and interior HSPMSM. Furthermore, the rotor dynamics analysis and vibration noise analysis on M2 are performed, and the infuence of PMS on the stress and vibration noise of both motors’ rotors is summarized. This article proposes a parameter preprocessing grouping multiphysical multi-objective high-dimensional multilevel optimization method. Taking M2 as an example, a global optimization design was carried out for the high-dimensional structural parameters brought by PMS, which improved the electromagnetic performance of M2 and reduced the vibration noise and rotor stress.

기어 특성을 고려한 전기철도용 마그네틱 기어 일체형 영구자석 전동기의 성능 분석

정거철(Geochul Jeong),정동훈(Dong-Hoon Jung) 대한전기학회 2021 전기학회논문지 Vol.70 No.3

This paper is a research paper on the performance analysis of magnetic gear integrated permanent magnet motor for electric railways considering gear characteristics. In the current industry, the drive system consists of mechanical gear and motor, which reduce or decrease the mechanical output speed of the motor by slowing down the mechanical output speed of the motor. However, mechanical gear have disadvantages such as maintenance costs and noise and vibration due to the wear of contact teeth, and the combined mechanical gear and motor driving systems are very complex in structure. Furthermore, research on contactless magnetic gear is actively underway to compensate for the shortcomings of these mechanical gear, but the driving system still has a complex structure with gear and motor coupling. Therefore, these driving systems need to be simplified, and in high-capacity driving systems, such as commercial and railway vehicles, which require high-torque at low speeds, mechanical gear and motor are integrated and lightweight. In this paper, we propose a magnetic gear integrated permanent magnet motor that can be structurally simplified and lightweight compared to conventional driving systems, and performance analysis on magnetic gear integrated permanent magnet motor considering gear characteristics. In conclusion, we propose a model of a magnetic gear integrated permanent magnet motor with high performance characteristics.

고밀도 토크를 가지는 5상 영구자석형 전동기의 약계자 제어

김남훈 전력전자학회 2007 전력전자학회 논문지 Vol.12 No.4

This paper investigates the field weakening operation of a five-phase permanent magnet motor. The proposed motor has concentrated windings such that the produced back-EMF is almost trapezoidal and is supplied with the combined sinusoidal plus third harmonic of currents to produce trapezoidal current. Therefore this motor, while generating the same average torque as an equivalent permanent magnet brushless dc motor, overcomes its disadvantages. It is shown that torque producing and flux producing components of current for this motor can be decoupled by using multiple reference frame transformation. Therefore, Vector control is easily applicable to the motor. This motor has benefits such as high torque density of a BLDC motor below the rated speed and controllability of PMSM above the rated speed and during the field weakening region and simulation and experimental results are provided to prove the validity of the superior performance of this drive. 본 논문에서는 영구자석형 5상 전동기(Five-phase permanent magnet motor)의 약계자 제어에 대한 연구를 수행한다. 제안된 전동기는 집중권 방식의 권선분포를 가지고 있고 사다리꼴 형태의 역기전력을 나타내고 있으며, 사다리꼴 형태의 전류를 인가하기 위하여 사인파의 기본파 성분에 3고조파 성분을 첨가하였다. 따라서 BLDC 전동기(Brushless dc motor)와 등가적으로 같은 평균토크를 발생시키면서 BLDC 전동기의 단점을 극복할 수 있었다. 전동기 전류의 토크성분과 자속성분은 다중 레퍼런스 프래임을 이용하여 분리할 수 있었으며, 결과적으로 쉽게 벡터제어가 이루어질 수 있었다. 사용된 전동기는 고속영역에서부터 저속영역까지 BLDC 전동기와 같이 높은 토크 밀도를 가지며, 약계자 영역이나 고속영역에서 영구자석형 전동기와 같이 제어의 용이함을 가진다는 장점을 가지고 있으며 실험결과를 통하여 제안된 전동기와 알고리즘을 검증하였다.

Optimal Rotor Design of IPM Motor for Improving Torque Performance Considering Thermal Demagnetization of Magnet

Sunghoon Lim,Seungjae Min,Jung-Pyo Hong IEEE 2015 IEEE transactions on magnetics Vol.51 No.3

<P>This paper proposes a new design technique for improving torque performance of interior permanent magnet (IPM) motors with consideration of the thermal characteristic of magnet. To verify the driving performance of IPM motor at operating temperature, a magnetic-thermal coupled analysis was performed with a heat source, such as iron loss and copper loss, and the thermal characteristics of permanent magnet (PM) is considered to define the magnetic property. The optimization problem is formulated to minimize the harmonics of magnetic flux, which cause iron loss, as well as to maximize the output torque for satisfying the design target. To obtain an optimal rotor shape of the IPM motor, which is composed of both PM and ferromagnetic material, a multi-phase level set model is employed for representing the precise boundaries of the magnetic materials. A design example of a motor with Nd-Fe-B magnet, which has a tendency to be demagnetized at high temperature, is provided to verify the effectiveness of the proposed method.</P>