Measurement and Analysis of Torque Ripple in Inverter Driven Electric Machines

2021 ◽  
Vol 263 (6) ◽  
pp. 227-235
Author(s):  
Mitchell Marks
Keyword(s):  
Best Practices ◽  
Torque Ripple ◽  
Electric Machines ◽  
Slow Speed ◽  
Noise And Vibration ◽  
Torque Response ◽  
Measurement And Analysis ◽  
Method Of Measurement ◽  
Different Sources ◽  
Speed Method

Torque ripple in electric machines can create both noise and vibration. While torque ripple is often well understood theoretically, it is much more difficult to accurately predict and measure. Often torque ripple is measured as a function of magnets and slot interaction at extremely low speed, but this can only be extrapolated to understand its implications for noise and vibration and is not useful for understanding torque response during dynamic scenarios like a change in load. The slow speed method of measurement also neglects possible switching effects on the torque profile. This paper will explore challenges in measuring the different sources of torque ripple and give an alternative method to measure torque ripple at higher speeds and also dynamically. This will include best practices and examples.

scholarly journals Improved Immune Algorithm Combined with Steepest Descent Method for Optimal Design of IPMSM for FCEV Traction Motor

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3904
Author(s):  
Ji-Chang Son ◽  
Myung-Ki Baek ◽  
Sang-Hun Park ◽  
Dong-Kuk Lim
Keyword(s):  
Optimal Design ◽  
Permanent Magnet Synchronous Motor ◽  
Torque Ripple ◽  
Descent Method ◽  
Immune Algorithm ◽  
Electric Machines ◽  
Steepest Descent Method ◽  
Superior Performance ◽  
Element Analysis ◽  
Traction Motor

In this paper, an improved immune algorithm (IIA) was proposed for the torque ripple reduction optimal design of an interior permanent magnet synchronous motor (IPMSM) for a fuel cell electric vehicle (FCEV) traction motor. When designing electric machines, both global and local solutions of optimal designs are required as design result should be compared in various aspects, including torque, torque ripple, and cogging torque. To lessen the computational burden of optimization using finite element analysis, the IIA proposes a method to efficiently adjust the generation of additional samples. The superior performance of the IIA was verified through the comparison of optimization results with conventional optimization methods in three mathematical test functions. The optimal design of an IPMSM using the IIA was conducted to verify the applicability in the design of practical electric machines.

Measurement and Analysis of Triboelectric Surface Charge

2021 ◽  
Vol 30 (1/2) ◽  
pp. 7-11
Author(s):  
Jinhong PARK ◽  
Jinhyeok CHOI ◽  
Sang Hyeok PARK ◽  
Minbaek LEE
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Surface Properties ◽  
Elastic Moduli ◽  
Surface Charges ◽  
Contact Electrification ◽  
Measurement And Analysis ◽  
Different Types ◽  
Triboelectric Charging ◽  
Method Of Measurement

Contact electrification occurs when two isolated objects come into contact. Such a phenomenon led humans to first realization of the existence of electricity. Until now, the main causes of the triboelectric charging phenomenon have generally been thought to be the transfer of electrons, ions, and materials. This article, however, is limited to electron transfer on the surface, which is regarded as a general case not limited to specific situations. The contact between two objects occurs between the two surfaces; therefore, the surface properties of the material under examination are the most important properties in triboelectric charge transfer. The surface properties may include the types of materials in contact, their energy states, the roughnesses of their surfaces, and their elastic moduli. In this regard, we introduce here the current understanding of the energy band structures involved in the different types of materials, the method of measurement, an analysis of surface charges, and related applications.

scholarly journals Evaluating Rank-Coherence of Crowd Rating in Customer Satisfaction

2020 ◽  
Author(s):  
Venera Tomaselli ◽  
Giulio Giacomo Cantone
Keyword(s):  
Customer Satisfaction ◽  
Ad Hoc ◽  
Data Gathering ◽  
Social Contexts ◽  
Public Utility ◽  
Public Disclosure ◽  
Measurement And Analysis ◽  
Method Of Measurement ◽  
Weighted Measure ◽  
Rating Information

AbstractCrowd rating is a continuous and public process of data gathering that allows the display of general quantitative opinions on a topic from online anonymous networks as they are crowds. Online platforms leveraged these technologies to improve predictive tasks in marketing. However, we argue for a different employment of crowd rating as a tool of public utility to support social contexts suffering to adverse selection, like tourism. This aim needs to deal with issues in both method of measurement and analysis of data, and with common biases associated to public disclosure of rating information. We propose an evaluative method to investigate fairness of common measures of rating procedures with the peculiar perspective of assessing linearity of the ranked outcomes. This is tested on a longitudinal observational case of 7 years of customer satisfaction ratings, for a total amount of 26.888 reviews. According to the results obtained from the sampled dataset, analysed with the proposed evaluative method, there is a trade-off between loss of (potentially) biased information on ratings and fairness of the resulting rankings. However, computing an ad hoc unbiased ranking case, the ranking outcome through the time-weighted measure is not significantly different from the ad hoc unbiased case.

scholarly journals Extending DC Bus Utilization for Induction Motors with Stator Flux Oriented Direct Torque Control

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 374
Author(s):  
Tomas Esparza Sola ◽  
Huang-Jen Chiu ◽  
Yu-Chen Liu ◽  
Arief Noor Rahman
Keyword(s):  
Direct Torque Control ◽  
Harmonic Distortion ◽  
Torque Ripple ◽  
Torque Control ◽  
Smooth Transition ◽  
Torque Response ◽  
Dc Bus ◽  
Low Torque ◽  
Stator Flux ◽  
Stator Flux Oriented

This paper presents a method to extend the DC bus utilization on an induction motor (IM) by using a combination of Space-Vector Modulated Direct Torque Control (DTC–SVM) and conventional DTC. The scheme proposed in this paper exploits the advantages of both control methods. During the linear region, it allows for a low torque ripple and low current harmonic distortion (THD). During the overmodulation region, it allows for the fastest torque response up to the six-step operation region. In both regions, there is complete independence of the motor parameters. The paper describes a way to provide a smooth transition between the two control schemes. Non-linearities affect the stator flux angle estimation, which leads to the inability to decouple torque and flux. To overcome this problem, a novel PI-based control scheme as well as a simplification on the decoupling terms’ calculation are proposed. Simulation and experimental results are presented to verify the feasibility of the proposed method.

Analysis of Electromagnetic Excitation Sources of Noise and Vibration in Interior Permanent Magnet Motor

2001 ◽  
Author(s):  
Hong-Seok Ko ◽  
Kwang-Joon Kim
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Permanent Magnet ◽  
Torque Ripple ◽  
Permanent Magnet Motor ◽  
Electromagnetic Excitation ◽  
Noise And Vibration ◽  
Current Harmonics ◽  
Interior Permanent Magnet ◽  
Interior Permanent Magnet Motor

Abstract The purpose of this paper is to characterize electromagnetic excitation forces in an IPM (Interior Permanent Magnet) motor and to analyze their effects on noise and vibration. To do this, the electromagnetic excitation forces are classified into three parts and contribution of each to the noise and vibration is investigated. The first is cogging torque; in order to overcome drawbacks of finite element method in the initial design stage, an analytical method is proposed. The second is electrical torque ripple due to current harmonics; a simple equation for characterizing the current harmonics with respect to the electrical torque ripple is developed. The third is the excitation force related to distribution of electromagnetic forces in air-gap; existence of this force is understood by finite element method. The influence of the electromagnetic forces on the noise and vibration is investigated by doing modal analysis and operational deflection shape analysis.

scholarly journals Low cogging torque design and simplified model-free predictive current control for radial-flux dual three-phase permanent magnet electric machines

2019 ◽  
Vol 11 (12) ◽  
pp. 168781401989164
Author(s):  
Hsing-Cheng Yu ◽  
Hung-Wei Lai ◽  
Li-Jhen Chen ◽  
Cheng-Kai Lin
Keyword(s):  
Permanent Magnet ◽  
Control Method ◽  
Torque Ripple ◽  
Electric Machines ◽  
Current Control ◽  
Simplified Model ◽  
Cogging Torque ◽  
Model Free ◽  
Radial Flux ◽  
Three Phase

This study presents two improved designs of eccentric-shaped permanent magnets and teeth-shaped stators in radial-flux dual three-phase permanent magnet electric machines to reduce cogging torque and torque ripple. The finite element analysis (ANSYS Electromagnetics) has been adopted in simulation, and real radial-flux dual three-phase permanent magnet electric machines have been fabricated in experiment to verify the study. Using the radial-flux dual three-phase permanent magnet electric machines in electric machine systems can improve the reliability and obtain higher output torque. In electrical drives and control, a simplified model-free predictive current control method has been proposed and implemented to drive the radial-flux dual three-phase permanent magnet electric machines, and the control law has been achieved by a TMS320F28377S microcontroller of Texas Instruments. The simplified model-free predictive current control method is senseless to parameter variations and back electromotive force of the permanent magnet electric machines, and only needs current sensors to detect six-phase current. The optimal one has been chosen by 14 various switching modes, which has the minimum cost function, and then the converter can be directly driven and controlled in the next sampling period. The features of the simplified model-free predictive current control method can reduce the algorithm calculation and avoid the defect of conventional model-based predictive current control scheme. A proportional-integral speed controller has also been designed to achieve the speed response of the fixed-speed tracking effect. Finally, the feasibility and effectiveness of the proposed simplified model-free predictive current control method for the dual three-phase permanent magnet electric machines can be verified in the experimental and quantitative results.

Fuzzy Logic Application for Intelligent Control of An Asynchronous Machine

2017 ◽  
Vol 7 (1) ◽  
pp. 61
Author(s):  
Zineb Mekrini ◽  
Seddik Bri
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Direct Torque Control ◽  
Torque Ripple ◽  
Torque Control ◽  
Asynchronous Machine ◽  
Torque Response ◽  
Q Model ◽  
High Torque ◽  
Stator Flux

<p>The aim of this article is propose a method to improve the direct torque control and design a Fuzzy Logic based Controller which can take necessary control action to provide the desired torque and flux of an asynchronous machine. It’s widely used in the industrial application areas due to several features such as fast torque response and less dependence on the rotor parameters. The major problem that is usually associated with DTC control is the high torque ripple as it is not directly controlled. The high torque ripple causes vibrations to the motor which may lead to component lose, bearing failure or resonance. The fuzzy logic controller is applied to reduce electromagnetic torque ripple. In this proposed technique, the two hysteresis controllers are replaced by fuzzy logic controllers and a methodology for implementation of a rule based fuzzy logic controller are presented. The simulation by Matlab/Simulink was built which includes induction motor d-q model, inverter model, fuzzy logic switching table and the stator flux and torque estimator. The validity of the proposed method is confirmed by the simulative results of the whole drive system and results are compared with conventional DTC method. </p>

Vehicle Interior Noise Measurement and Analysis

2011 ◽  
Vol 467-469 ◽  
pp. 1072-1077
Author(s):  
Zhong Xin Li ◽  
Guang Ping Wang ◽  
Shen Xu Wang ◽  
Hong Jiang
Keyword(s):  
Internal Noise ◽  
Interior Noise ◽  
Vibration Acceleration ◽  
Vehicle Interior ◽  
Noise Sources ◽  
Noise And Vibration ◽  
Order Analysis ◽  
Vehicle Interior Noise ◽  
Measurement And Analysis ◽  
Acceleration Signals

A method of vehicle interior noise order analysis was presented to resolve the loud noise problem in a new indigenous vehicle. Sound and vibration properties of the vehicle were tested. The interior noise and vibration acceleration signals at different positions were obtained, and the major sources of noise and vibration were identified. Base on these results, modifications were proposed for different noise sources. The results provide a reference for the optimal design of vehicle motor and transmission system and the internal noise control.

scholarly journals Addressing Compound Reactivity and Aggregation Assay Interferences: Case Studies of Biochemical High-Throughput Screening Campaigns Benefiting from the National Institutes of Health Assay Guidance Manual Guidelines

2021 ◽  
pp. 247255522110262
Author(s):  
Nathan P. Coussens ◽  
Douglas S. Auld ◽  
Jonathan R. Thielman ◽  
Bridget K. Wagner ◽  
Jayme L. Dahlin
Keyword(s):  
Best Practices ◽  
High Throughput ◽  
High Throughput Screening ◽  
New Technologies ◽  
National Institutes Of Health ◽  
High Yield ◽  
Topic Area ◽  
Aggregation Assay ◽  
Biological Assays ◽  
Different Sources

Compound-dependent assay interferences represent a continued burden in drug and chemical probe discovery. The open-source National Institutes of Health/National Center for Advancing Translational Sciences (NIH/NCATS) Assay Guidance Manual (AGM) established an “Assay Artifacts and Interferences” section to address different sources of artifacts and interferences in biological assays. In addition to the frequent introduction of new chapters in this important topic area, older chapters are periodically updated by experts from academia, industry, and government to include new technologies and practices. Section chapters describe many best practices for mitigating and identifying compound-dependent assay interferences. Using two previously reported biochemical high-throughput screening campaigns for small-molecule inhibitors of the epigenetic targets Rtt109 and NSD2, the authors review best practices and direct readers to high-yield resources in the AGM and elsewhere for the mitigation and identification of compound-dependent reactivity and aggregation assay interferences.

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