Torque ripple analysis for IPM AC motors

2014 ◽  
Vol 33 (5) ◽  
pp. 1514-1526 ◽  
Author(s):  
Jianxin Shen ◽  
Dan Shi ◽  
Canfei Wang ◽  
Peng Li ◽  
Kang Wang ◽  
...  
Keyword(s):  
Torque Ripple ◽  
New Method ◽  
Element Analysis ◽  
Cogging Torque ◽  
Content Type ◽  
Ac Motors ◽  
Ac Motor ◽  
Interior Permanent Magnet ◽  
Novel Method ◽  
Irregular Variation

Purpose – The purpose of this paper is to investigate a new cause of torque ripple in interior permanent magnet (IPM) alternating current (AC) motors, which is common but has hardly been studied. The paper also proposes a new method to suppress the total torque ripple. Design/methodology/approach – Besides the well-known cogging torque and mutual torque ripple, a new ripple which exists in the reluctance torque is found. It is verified with both analytical model and finite element analysis. Also, a novel method is proposed to reduce the reluctance torque ripple, with experimental validation. Findings – It is usually said that the winding inductances of an IPM AC motor vary sinusoidally with the rotor position, thus, the d-axis and q-axis inductances are constant, whilst the reluctance torque is smooth. However, in most practical motors, the inductances vary irregularly, causing a significant ripple in the reluctance torque. Moreover, in machine design, it is always desirable to suppress the cogging torque as much as possible. However, in this paper, it is proved that the cogging torque can remain and be used to cancel the reluctance torque ripple. Originality/value – Torque ripple in the IPM AC motors is usually reduced by suppressing the cogging torque and making both back electromotive forces and currents sinusoidal. However, this paper reveals the new cause of the torque ripple due to the irregular variation of winding inductances. Moreover, the paper gives a new method to cancel the reluctance torque ripple with the cogging torque.

Optimal design of low-cost IPM AC motor

2014 ◽  
Vol 33 (5) ◽  
pp. 1587-1598 ◽  
Author(s):  
Jianxin Shen ◽  
Kang Wang ◽  
Dan Shi ◽  
Canfei Wang ◽  
Mengjia Jin
Keyword(s):  
Optimal Design ◽  
Permanent Magnet ◽  
Field Distribution ◽  
Low Cost ◽  
Air Gap ◽  
Optimized Design ◽  
Cogging Torque ◽  
Content Type ◽  
Ac Motors ◽  
Ac Motor

Purpose – The purpose of this paper is to present the optimal design of a low-cost interior permanent magnet (IPM) alternating current (AC) motor. It examines the influence of the permanent magnet (PM) materials, and proposes a simple and practical method of optimizing the air-gap field to achieve sinusoidal back electromotive force (EMF), and to reduce the cogging torque. Design/methodology/approach – IPM AC motors with different magnet materials and various topologies are comparatively studied. Finite element method (FEM) is used to predict the performances of these designs. Material costs and manufacture costs are both taken into account. Finally, an optimized design is prototyped and tested, validating the design considerations. Findings – In an IPM AC motor, even if the rotor outer profile is round, the air-gap field distribution can be fined, while the cogging torque can be significantly reduced, by properly shaping the stator tooth tips. Nevertheless, this technique is usually applicable to motor configurations with concentrated windings, but not to those with distributed windings. Originality/value – While using ferrite magnets for PM AC motors with a kW power, interior magnets are usually inserted in V-shaped slots, and the rotor outer profile is often shaped in order to enhance the air-gap field distribution. However, such a rotor configuration usually increases the manufacture costs, and also deteriorates the consistency of mass production. Therefore, a new motor configuration with a round rotor outer profile and shaped stator tooth tips is proposed. It can not only overcome the aforementioned problems, but also improve the motor performance.

Analytical sub-domain model for predicting open-circuit field of permanent magnet vernier machine accounting for tooth tips

2016 ◽  
Vol 35 (2) ◽  
pp. 624-640 ◽  
Author(s):  
Y. Oner ◽  
Z.Q. Zhu ◽  
L.J. Wu ◽  
X. Ge
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Open Circuit ◽  
Air Gap ◽  
Domain Model ◽  
Direct Drive ◽  
Element Analysis ◽  
Cogging Torque ◽  
Content Type ◽  
Flux Modulation

Purpose – Due to high electromagnetic torque at low speed, vernier machines are suitable for direct-drive applications such as electric vehicles and wind power generators. The purpose of this paper is to present an exact sub-domain model for analytically predicting the open-circuit magnetic field of permanent magnet vernier machine (PMVM) including tooth tips. The entire field domain is divided into five regions, viz. magnets, air gap, slot openings, slots, and flux-modulation pole slots (FMPs). The model accounts for the influence of interaction between PMs, FMPs and slots, and radial/parallel magnetization. Design/methodology/approach – Magnetic field distributions for slot and air-gap, flux linkage, back-EMF and cogging torque waveforms are obtained from the analytical method and validated by finite element analysis (FEA). Findings – It is found that the developed sub-domain model including tooth tips is very accurate and is applicable to PMVM having any combination of slots/FMPs/PMs. Originality/value – The main contributions include: accurate sub-domain model for PMVM is proposed for open-circuit including tooth-tip which cannot be accounted for in literature; the model accounts the interaction between flux modulation pole (FMP) and slot; developed sub-domain model is accurate and applicable to any slot/FMP/PM combinations; and it has investigated the influence of FMP/slot opening width/height on cogging torque.

Torque imporvement of IPM motors with skewing magnetic designs

2021 ◽  
pp. 3-10
Author(s):  
Dinh Hai Linh
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Torque Ripple ◽  
Maintenance Cost ◽  
Permanent Magnet Motor ◽  
Element Analysis ◽  
Speed Range ◽  
Interior Permanent Magnet ◽  
Interior Permanent Magnet Motor ◽  
Wide Speed Range

In this paper, a type interior permanent magnet synchronous motor designs is proposed for sport scooter application to improve constant torque wide speed performance. Interior Permanent Magnet machines are widely used in automotive applications for their wide-speed range operation and low maintenance cost. An existing permanent magnet motor (commercial QS Motor) is 3 kW-3000 rpm. In order to improve torque and power in wide speed range, a IPM electric motor 5.5 kW -5000 rpm can run up to 100 km/h: An Step-Skewing Interior Permanent Magnet motor alternatives is designed and optimized in detail with optimal magnetic segment V shape. The electromagnetic charateristics of Interior Permanent Magnet motors with V shape are compared with the reference Surface Permanent Magnet motor for the same geometry parameter requirements. Detailed loss and efficiency result is also analyzed at rate and maximum speeds. A prototype motor is manufactured, and initial experimental tests are performed. Detailed comparison between Finite Element Analysis and test data are also presented. It is shown that it is possible to have an optimized Interior Permanent Magnet motor for such high-speed traction application. This paper will figure out optimal angle of magnetic V shape for maximum torque and minimum torque ripple.

Analysis of torque ripple and fault-tolerant capability for a 16/10 segmented switched reluctance motor in HEV applications

2019 ◽  
Vol 38 (6) ◽  
pp. 1725-1737
Author(s):  
Xiaodong Sun ◽  
Jiangling Wu ◽  
Shaohua Wang ◽  
Kaikai Diao ◽  
Zebin Yang
Keyword(s):  
Fault Tolerant ◽  
Switched Reluctance Motor ◽  
Torque Ripple ◽  
Experimental Results ◽  
Element Analysis ◽  
Content Type ◽  
Switched Reluctance ◽  
Output Torque ◽  
Reluctance Motor ◽  
Lower Torque

Purpose The torque ripple and fault-tolerant capability are the two main problems for the switched reluctance motors (SRMs) in applications. The purpose of this paper, therefore, is to propose a novel 16/10 segmented SRM (SSRM) to reduce the torque ripple and improve the fault-tolerant capability in this work. Design/methodology/approach The stator of the proposed SSRM is composed of exciting and auxiliary stator poles, while the rotor consists of a series of discrete segments. The fault-tolerant and torque ripple characteristics of the proposed SSRM are studied by the finite element analysis (FEA) method. Meanwhile, the characteristics of the SSRM are compared with those of a conventional SRM with 8/6 stator/rotor poles. Finally, FEA and experimental results are provided to validate the static and dynamic characteristics of the proposed SSRM. Findings It is found that the proposed novel 16/10 SSRM for the application in the belt-driven starter generator (BSG) possesses these functions: less mutual inductance and high fault-tolerant capability. It is also found that the proposed SSRM provides lower torque ripple and higher output torque. Finally, the experimental results validate that the proposed SSRM runs with lower torque ripple, better output torque and fault-tolerant characteristics, making it an ideal candidate for the BSG and similar systems. Originality/value This paper presents the analysis of torque ripple and fault-tolerant capability for a 16/10 segmented switched reluctance motor in hybrid electric vehicles. Using FEA simulation and building a test bench to verify the proposed SSRM’s superiority in both torque ripple and fault-tolerant capability.

Design Comparison of Fractional-Slot IPM Machine Types for an Electric Power Steering Application

2010 ◽  
Vol 670 ◽  
pp. 243-251
Author(s):  
Chang Chou Hwang ◽  
Hsing Cheng Chang ◽  
Ming Te Ho ◽  
Cheng Tsung Liu
Keyword(s):  
Electric Power ◽  
Torque Ripple ◽  
Parameter Method ◽  
Electric Power Steering ◽  
Element Analysis ◽  
Power Steering ◽  
Performance Requirements ◽  
Interior Permanent Magnet ◽  
Fractional Slot ◽  
Design Comparison

This paper deals with the design comparison of interior permanent magnet (IPM) motors with fractional-slot winding configurations for an electric power steering (EPS) application. By making comparisons of these configurations based on cogging torque, torque ripple, average torque, and efficiency, an IPM rotor configuration has been chosen for use as a prototype motor. The Taguchi parameter method coupled with the finite element analysis (FEA) is employed to achieve the desired performance requirements within a reasonable geometry. To assess the rated current and thermal behavior of the motor, the lumped circuit models are conducted.

Electromagnetic Performance due to Tooth-tip Design in Fractional-slot PM Brushless Machines

2015 ◽  
Vol 6 (4) ◽  
pp. 860
Author(s):  
Mohd Luqman Mohd Jamil ◽  
Zulfikri Zaki Zolkapli ◽  
Auzani Jidin ◽  
Raja Nor Firdaus Raja Othman ◽  
Tole Sutikno
Keyword(s):  
Double Layer ◽  
Great Influence ◽  
Single Layer ◽  
Torque Ripple ◽  
Element Analysis ◽  
Cogging Torque ◽  
Torque Density ◽  
Iron Modification ◽  
Winding Machine ◽  
Electromagnetic Performance

Permanent Magnet (PM) machines are favorable as an alternative to other machine topologies due to simpler construction and high torque density. However, it may result hight torque ripple due to an influence of cogging torque and electronic commutation. In this paper, comparisons of phase back-emf, static torque and cogging torque due to influence of tooth-tip asymmetry in 12-slot/10-pole double-layer and 12-slot/10-pole single layer winding machines are carried out using 2D Finite-Element Analysis. At rated condition, the stator asymmetry has great influence on the torque performance as there is significant reduction of torque ripple in 12-slot/10-pole mahine equipped with single layer winding than one equipped with double layer winding machine. It si confirmed that an optimum torque performance is desirable via stator iron modification in PM machines.

scholarly journals Analysis of Torque Ripple and Cogging Torque Reduction in Electric Vehicle Traction Platform Applying Rotor Notched Design

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3053 ◽  
Author(s):  
Myeong-Hwan Hwang ◽  
Hae-Sol Lee ◽  
Hyun-Rok Cha
Keyword(s):  
Permanent Magnet ◽  
Torque Ripple ◽  
Field Analysis ◽  
Permanent Magnet Motors ◽  
Primary Methods ◽  
Cogging Torque ◽  
Electric Cars ◽  
Electric Control ◽  
Interior Permanent Magnet ◽  
Rotor Shape

Drive motors, which are used in the drive modules of electric cars, are interior permanent magnet motors. These motors tend to have high cogging torque and torque ripple, which leads to the generation of high vibration and noise. Several studies have attempted to determine methods of reducing the cogging torque and torque ripple in interior permanent magnet motors. The primary methods of reducing the cogging torque involve either electric control or mechanical means. Herein, the authors focused on a mechanical method to reduce the cogging torque and torque ripple. Although various methods of reducing vibration and noise mechanically exist, there is no widely-known comparative analyses on reducing the vibration and noise by designing a notched rotor shape. Therefore, this paper proposes a method of reducing vibration and noise mechanically by designing a notched rotor shape. In the comparative analysis performed herein, the motor stator and rotor were set to be the same size, and electromagnetic field analysis was performed to determine a notch shape that is suitable for the rotor and that generates reasonable vibration and noise.

A new method to access information for underground omni-dimensional vibration vector

Sensor Review ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 125-132 ◽  
Author(s):  
Jian Li ◽  
Ying Liu ◽  
Yan Han ◽  
Xianhui Chen
Keyword(s):  
Vibration Signal ◽  
Vibration Sensor ◽  
New Method ◽  
Underground Explosion ◽  
Sensor Calibration ◽  
Signal Acquisition ◽  
Element Analysis ◽  
Content Type ◽  
Sensor Structure ◽  
Vector Signal

Purpose – The purpose of this paper is to propose a new method to achieve omni-directional vibration vector signal acquisition, and use this method to improve the accuracy of the underground explosion point localization. Design/methodology/approach – Following an introduction, this paper describes the design principle of a sensor structure, and discusses the rationality of the spherical structure of the sensor through finite element analysis. The sensor prototype is designed according to the above method, and its performance is tested by the sensor calibration experiment. Finally, applications are also discussed. Findings – This paper shows that the method for underground omni-directional vibration signal acquisition is reasonable and feasible. The vibration sensor, designed by this method, of which the triaxial dynamic characteristics are consistent, and the three-dimensional vibration information acquired by this sensor can achieve high-precision localization for an underground explosion point. Originality/value – The paper describes a new method for omni-directional vibration vector signal acquisition. The vibration sensor is developed based on this method, which has a broad application prospect in the positioning of an underground explosion point, the evaluation of explosive power and other underground projects.

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