The Experts below are selected from a list of 100017 Experts worldwide ranked by ideXlab platform
Akira Chiba - One of the best experts on this subject based on the ideXlab platform.
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Acoustic Noise reduction of a high efficiency switched reluctance motor for hybrid electric vehicles with novel current waveform
IEEE Transactions on Industry Applications, 2019Co-Authors: Masachika Kawa, Kyohei Kiyota, Jihad Furqani, Akira ChibaAbstract:One of the major topics of switched reluctance machines (SRMs) is how to reduce the Acoustic Noise and vibration without decreasing the efficiency. In this paper, a few novel current profiling methods are proposed to reduce the Acoustic Noise by flatting the radial force sum and to reduce optimal torque ripple with best efforts to enhance the efficiency. The proposed method is adopted to the 18/12 pole SRM, which has identical outer dimensions and competitive torque, output power, efficiency, and operating region of the permanent-magnet motor used in the hybrid vehicles. It is found that the proposed method can improve not only the radial force ripple characteristic but also the iron loss minimization. The efficiency enhancement is also found to be possible in a few cases depending on the demanding criteria; thanks to the phase shift of the fundamental component of the current waveform. The proposed method is verified in the experiments.
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current reference selection for Acoustic Noise reduction in two switched reluctance motors by flattening radial force sum
IEEE Transactions on Industry Applications, 2019Co-Authors: Jihad Furqani, Kyohei Kiyota, Masachika Kawa, Candra Adi Wiguna, Nanaho Kawata, Akira ChibaAbstract:In this paper, a selection of a few current references for Acoustic Noise reduction in the 36–24 and the 18–12 switched reluctance motors is presented. It is seen that the difference in radial force profile results in few optimal current references. It is found that the optimal current reference with extreme radial force sum flattening results in increased rms current and loss in a magnetically saturated region of the 18–12 SRM. Thus, proper selection of the current references is necessary. Analysis, simulation, and experimental results are presented with the conventional and optimal currents to verify the effectiveness of flattening radial force sum method in Acoustic Noise reduction. It is shown that effective Acoustic Noise reduction and efficiency improvement are confirmed with proposed current reference selection.
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Acoustic Noise reduction of a high efficiency switched reluctance motor for hybrid electric vehicles with novel current waveform
International Electric Machines and Drives Conference, 2017Co-Authors: Masachika Kawa, Kyohei Kiyota, Jihad Furqani, Akira ChibaAbstract:One of the major topics of switched reluctance machines (SRMs) is how to reduce the Acoustic Noise and vibration without the decrease in efficiency. In this paper, a novel current profiling method is proposed to reduce the rms current while flatting the radial force sum to reduce the Acoustic Noise and vibration. The proposed method is adopted to the 18/12 SRM which has the competitive outer dimensions, torque, output power, efficiency and operating region of the permanent magnet motor used in the hybrid vehicles.
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Acoustic Noise reduction of switched reluctance motor with reduced rms current and enhanced efficiency
IEEE Transactions on Energy Conversion, 2016Co-Authors: Jacob Bayless, Noboru Kurihara, Hiroya Sugimoto, Akira ChibaAbstract:A general condition is derived for the reduction of stator vibrations in multiphase switched-reluctance motors (SRMs) through current regulation in a low-torque and low-speed region. By exploring a wider space of solutions than had previously been examined, optimized solutions are found which simultaneously minimize Acoustic Noise and vibration, and also minimize qualities such as copper loss, peak current, or torque ripple. In particular, the current profile is represented as a Fourier sum of three harmonics and the phase shift of these harmonics is examined. Experiments show a reduction of motor losses by 10% to 20% relative to previous attempts at proposed waveforms, while achieving a similar reduction in Acoustic Noise and vibration. In general, current profiling for Noise reduction resulted in reduced efficiency; however, in this paper, it was found that motor efficiency can be enhanced relative to conventional square waveform current regulation, while reducing Acoustic Noise and vibration significantly.
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Cylindrical rotor design for Acoustic Noise and windage loss reduction in switched reluctance motor for HEV applications
IEEE Transactions on Industry Applications, 2016Co-Authors: Kyohei Kiyota, Takeo Kakishima, Akira Chiba, M. A. RahmanAbstract:A switched reluctance motor (SRM) is one of the candidates of rare-earth-free motors for hybrid electric vehicles (HEVs). An SRM has been developed with same interior permanent magnet synchronous motor (IPMSM) dimensions having competitive maximum torque, operating area, and maximum efficiency. However, this SRM has a windage loss of 1.3 kW due to the salient poles of the SRM driven at the maximum rotational speed. In addition, considerable Acoustic Noise is caused by the salient poles. In this paper, a simple design of a cylindrical outer shape rotor is proposed, and a comparison with the conventional SRM rotor is carried out. It is found that the efficiency is improved due to the windage loss reduction. It is also found that the Acoustic Noise is significantly reduced in the proposed rotor design.
Ali Emadi - One of the best experts on this subject based on the ideXlab platform.
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a comprehensive analysis of the Acoustic Noise in an interior permanent magnet traction motor
European Conference on Cognitive Ergonomics, 2019Co-Authors: Jianbin Liang, Berker Bilgin, Yihui Li, Dhafar Alani, Ali EmadiAbstract:Modeling and analysis of Acoustic Noise is one of the important design phases for a traction motor in the Noise-sensitive applications, such as hybrid electric vehicles. This paper presents a comprehensive analysis on the Acoustic Noise and the radial force density harmonics in a 48/8 interior permanent magnet (IPM) traction motor designed for an electrified powertrain. Detailed Acoustic modeling and analysis based on the numerical method is presented. The techniques on improving the simulation accuracy and reducing the computation cost of the numerical modeling is also analyzed. The effect of the two-step skewed rotor on the radial force density harmonics is discussed. The sound pressure level waterfall diagram and the analysis of the radial force density harmonics confirm the dominant vibration mode and the dominant harmonics of the radial force density. The Acoustic Noise analysis process presented in this paper develops the basis for the Acoustic Noise reduction by optimizing the rotor stepped skew angles.
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radial force density analysis of switched reluctance machines the source of Acoustic Noise
IEEE Transactions on Transportation Electrification, 2019Co-Authors: Alan Dorneles Callegaro, Berker Bilgin, Jianbin Liang, James Weisheng Jiang, Ali EmadiAbstract:Closer attention has been given to the Acoustic Noise performance of electric motors as electrified powertrains penetrate into our transportation system. In particular, switched reluctance machine introduces a new challenge to Acoustic Noise aspect given that the temporal harmonics of high amplitudes on the radial direction can excite the natural frequencies of the main circumferential modes. A practical understanding of the radial force density decomposition is crucial in identifying the primary source of Acoustic Noise at different operating points, and it is the main contribution of this paper. An analytical expression is introduced to identify the temporal harmonic orders that excite different spatial mode shapes. The combination of the circumferential and temporal harmonic orders results in a force density surface wave that travels in the clockwise (CW) or counter CW direction. The mode excitation is investigated along with the sound pressure level produced by the primary vibrating mode shapes. Acoustic Noise characteristics for each mode and the corresponding natural frequency at different speeds have been analyzed by using a waterfall plot.
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Radial Force Shaping for Acoustic Noise Reduction in Switched Reluctance Machines
IEEE Transactions on Power Electronics, 2019Co-Authors: Alan Dorneles Callegaro, Berker Bilgin, Ali EmadiAbstract:Robustness, simple construction, and low cost are some of the advantages of switched reluctance machines (SRMs). These are all desirable characteristics of an electric motor, especially in the automotive sector, where high-temperature and high-speed operation, and low cost are always in demand. However, the Acoustic Noise generation by conventionally controlled SRMs can prevent its use in applications where Acoustic comfort is required. Acoustic Noise is radiated by the stator frame when a vibration mode is excited by the respective spatial order at a forcing frequency that is close to the stator's modal natural frequency. The excitation surface wave is the radial force density waveform, which is a function of time and spatial position. In this paper, a phase radial force shaping method is proposed by using harmonic content analysis. A generic function for the radial force shape is identified, whose parameters are calculated by an optimization algorithm to minimize the torque ripple for a given average torque. From the phase radial force profile, a current reference is obtained. The proposed methodology is experimentally validated with a four-phase 8/6 SRM through Acoustic Noise measurements at different speed and load conditions.
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hybrid Acoustic Noise analysis approach of conventional and mutually coupled switched reluctance motors
IEEE Transactions on Energy Conversion, 2017Co-Authors: Jianning Dong, Alan Dorneles Callegaro, Berker Bilgin, James Weisheng Jiang, Brock Howey, Ali EmadiAbstract:This paper presents a method to calculate the Acoustic Noise of conventional switched reluctance motor (CSRM) and mutually coupled switched reluctance motor (MCSRM). This method is based on dynamic electromagnetic models, combined with analytical estimation of the stator eigenmodes and radiation efficiency, considering the switching effects and frame effects. The proposed method is applied to predict and compare the Acoustic Noise performances of a CSRM and an MCSRM in a wide speed range. The results are validated using commercial finite element analysis software, JMAG for electromagnetics and ACTRAN for Acoustics. An acceleration test based on a setup with a 12/8 CSRM is used for experimental validation. Results show that the proposed method can provide reliable prediction of main Acoustic Noises during acceleration.
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Acoustic Noise analysis of a high speed high power switched reluctance machine frame effects
IEEE Transactions on Energy Conversion, 2016Co-Authors: Sandra M Castano, Berker Bilgin, Earl Fairall, Ali EmadiAbstract:This paper examines the effect of frame on the Acoustic Noise and vibration of a high-speed and high-power switched reluctance machine (SRM). Five types of frame/ribs are investigated, where different frame thicknesses, types of cooling ribs, and frame shapes have been analyzed. For this purpose, a 12/8 SRM has been designed at 22 000 r/min and 150 kW and two stages have been applied. In the first stage, a new equivalent stiffness of the frame is utilized in order to estimate the resonant frequencies for different frame shapes. The paper provides a mathematical calculation method and evaluates its effectiveness with finite-element simulations. The results indicate an improvement between 4% and 25% in the estimation natural frequencies. The second stage includes the vibration and Acoustic Noise analysis using 3-D finite-element method. Considerations for Acoustic Noise reduction in high-speed SRM using different frame types and cooling ribs are discussed. Particularly, radial and screw-type configurations represent a better solution to decrease the sound pressure level up to 12 dB.
Erik Borg - One of the best experts on this subject based on the ideXlab platform.
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mri Acoustic Noise sound pressure and frequency analysis
Journal of Magnetic Resonance Imaging, 1997Co-Authors: Allen S Counter, Ake Olofsson, Hans Grahn, Erik BorgAbstract:The large gradient colls used in MRI generate, simultaneously with the pulsed radiofrequency (RF) wave, Acoustic Noise of high intensity that has raised concern regarding hearing safety. The sound pressure levels (SPLs) and power spectra of MRI Acoustic Noise were measured at the position of the human head in the isocenter of five MRI systems and with 10 different pulse sequences used in clinical MR scanning. Each protocol, including magnetization-prepared rapid gradient echo (MP-RAGE; 113 dB SPL linear), fast gradient echo turbo (114 dB SPL linear), and spin echo Tl/2 mm (117 dB SPL linear), was found to have the high SPLs, rapid pulse rates, amplitude-modulated pulse envelopes, and multi-peaked spectra. Slice thickness and SPL were inversely related, and Tl-weighted images generated more intense Acoustic Noise than the proton-dense T2-weighted measures. The unflltered linear peak values provided more accurate measurements of the SPL and spectral content of the MRI Acoustic Noise than the commonly used dB A-weighted scale, which filters out the predominant low frequency components. Fourier analysis revealed predominantly low frequency energy peaks ranging from .05 to approximately.
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mri Acoustic Noise sound pressure and frequency analysis
Journal of Magnetic Resonance Imaging, 1997Co-Authors: Allen S Counter, Ake Olofsson, Hans Grahn, Erik BorgAbstract:The large gradient coils used in MRI generate, simultaneously with the pulsed radiofrequency (RF) wave, Acoustic Noise of high intensity that has raised concern regarding hearing safety. The sound pressure levels (SPLs) and power spectra of MRI Acoustic Noise were measured at the position of the human head in the isocenter of five MRI systems and with 10 different pulse sequences used in clinical MR scanning. Each protocol, including magnetization-prepared rapid gradient echo (MP-RAGE; 113 dB SPL linear), fast gradient echo turbo (114 dB SPL linear), and spin echo T1/2 mm (117 dB SPL linear), was found to have the high SPLs, rapid pulse rates, amplitude-modulated pulse envelopes, and multipeaked spectra. Since thickness and SPL were inversely related, the T1-weighted images generated more intense Acoustic Noise than the proton-dense T2-weighted measures. The unfiltered linear peak values provided more accurate measurements of the SPL and spectral content of the MRI Acoustic Noise than the commonly used dB A-weighted scale, which filters out the predominant low frequency components. Fourier analysis revealed predominantly low frequency energy peaks ranging from .05 to approximately 1 kHz, with a steep high frequency cutoff for each pulse sequence. Ear protectors of known attenuation ratings are recommended for all patients during MRI testing.
Angel V Peterchev - One of the best experts on this subject based on the ideXlab platform.
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double containment coil with enhanced winding mounting for transcranial magnetic stimulation with reduced Acoustic Noise
IEEE Transactions on Biomedical Engineering, 2021Co-Authors: Lari M Koponen, Stefan M Goetz, Angel V PeterchevAbstract:This work aims to reduce the Acoustic Noise level of transcranial magnetic stimulation (TMS) coils. TMS requires high currents (several thousand amperes) to be pulsed through the coil, which generates a loud Acoustic impulse whose peak sound pressure level (SPL) can exceed 130 dB(Z). This sound poses a risk to hearing and elicits unwanted neural activation of auditory brain circuits. $Methods$ : We propose a new double-containment coil with enhanced winding mounting (DCC), which utilizes Acoustic impedance mismatch to contain and dissipate the impulsive sound within an air-tight outer casing. The coil winding is potted into a rigid block, which is mounted to the outer casing through the block's Acoustic nodes that are subject to minimum vibration during the pulse. The rest of the winding block is isolated from the casing by an air gap, and the sound is absorbed by polyester fiber panels within the casing. The casing thickness under the winding center is minimized to maximize the electric field output. $Results$ : Compared to commercial figure-of-eight TMS coils, the DCC prototype has 18–41 dB(Z) lower peak SPL at matched stimulation strength, whilst providing 28% higher maximum stimulation strength than equally focal coils. $Conclusion$ : The DCC design greatly reduces the Acoustic Noise of TMS while increasing the achievable stimulation strength. $Significance$ : The Acoustic Noise reduction from our coil design is comparable to that provided by typical hearing protection devices. This coil design approach can enhance hearing safety and reduce auditory co-activations in the brain and other detrimental effects of TMS sound.
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double containment coil with enhanced winding mounting for transcranial magnetic stimulation with reduced Acoustic Noise
arXiv: Medical Physics, 2020Co-Authors: Lari M Koponen, Stefan M Goetz, Angel V PeterchevAbstract:Objective: This work aims to reduce the Acoustic Noise level of transcranial magnetic stimulation (TMS) coils. TMS requires high currents (several thousand amperes) to be pulsed through the coil, which generates a loud Acoustic impulse whose peak sound pressure level (SPL) can exceed 130 dB(Z). This sound poses a risk to hearing and elicits unwanted neural activation of auditory brain circuits. Methods: We propose a new double-containment coil with enhanced winding mounting (DCC), which utilizes Acoustic impedance mismatch to contain and dissipate the impulsive sound within an air-tight outer casing. The coil winding is potted in a rigid block, which is mounted to the outer casing by its Acoustic nodes that are subject to minimum vibration during the pulse. The rest of the winding block is isolated from the casing by an air gap, and sound is absorbed by foam within the casing. The casing thickness under the winding center is minimized to maximize the coil electric field output. Results: Compared to commercial figure-of-eight TMS coils, the DCC prototype has 10-33 dB(Z) lower SPL at matched stimulation strength, whilst providing 22% higher maximum stimulation strength than equally focal commercial coils. Conclusion: The DCC design greatly reduces the Acoustic Noise of TMS while increasing the achievable stimulation strength. Significance: The Acoustic Noise reduction from our coil design is comparable to that provided by typical hearing protection devices. This coil design approach can enhance hearing safety and reduce auditory co-activations in the brain and other detrimental effects of TMS sound.
Berker Bilgin - One of the best experts on this subject based on the ideXlab platform.
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a comprehensive analysis of the Acoustic Noise in an interior permanent magnet traction motor
European Conference on Cognitive Ergonomics, 2019Co-Authors: Jianbin Liang, Berker Bilgin, Yihui Li, Dhafar Alani, Ali EmadiAbstract:Modeling and analysis of Acoustic Noise is one of the important design phases for a traction motor in the Noise-sensitive applications, such as hybrid electric vehicles. This paper presents a comprehensive analysis on the Acoustic Noise and the radial force density harmonics in a 48/8 interior permanent magnet (IPM) traction motor designed for an electrified powertrain. Detailed Acoustic modeling and analysis based on the numerical method is presented. The techniques on improving the simulation accuracy and reducing the computation cost of the numerical modeling is also analyzed. The effect of the two-step skewed rotor on the radial force density harmonics is discussed. The sound pressure level waterfall diagram and the analysis of the radial force density harmonics confirm the dominant vibration mode and the dominant harmonics of the radial force density. The Acoustic Noise analysis process presented in this paper develops the basis for the Acoustic Noise reduction by optimizing the rotor stepped skew angles.
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radial force density analysis of switched reluctance machines the source of Acoustic Noise
IEEE Transactions on Transportation Electrification, 2019Co-Authors: Alan Dorneles Callegaro, Berker Bilgin, Jianbin Liang, James Weisheng Jiang, Ali EmadiAbstract:Closer attention has been given to the Acoustic Noise performance of electric motors as electrified powertrains penetrate into our transportation system. In particular, switched reluctance machine introduces a new challenge to Acoustic Noise aspect given that the temporal harmonics of high amplitudes on the radial direction can excite the natural frequencies of the main circumferential modes. A practical understanding of the radial force density decomposition is crucial in identifying the primary source of Acoustic Noise at different operating points, and it is the main contribution of this paper. An analytical expression is introduced to identify the temporal harmonic orders that excite different spatial mode shapes. The combination of the circumferential and temporal harmonic orders results in a force density surface wave that travels in the clockwise (CW) or counter CW direction. The mode excitation is investigated along with the sound pressure level produced by the primary vibrating mode shapes. Acoustic Noise characteristics for each mode and the corresponding natural frequency at different speeds have been analyzed by using a waterfall plot.
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Radial Force Shaping for Acoustic Noise Reduction in Switched Reluctance Machines
IEEE Transactions on Power Electronics, 2019Co-Authors: Alan Dorneles Callegaro, Berker Bilgin, Ali EmadiAbstract:Robustness, simple construction, and low cost are some of the advantages of switched reluctance machines (SRMs). These are all desirable characteristics of an electric motor, especially in the automotive sector, where high-temperature and high-speed operation, and low cost are always in demand. However, the Acoustic Noise generation by conventionally controlled SRMs can prevent its use in applications where Acoustic comfort is required. Acoustic Noise is radiated by the stator frame when a vibration mode is excited by the respective spatial order at a forcing frequency that is close to the stator's modal natural frequency. The excitation surface wave is the radial force density waveform, which is a function of time and spatial position. In this paper, a phase radial force shaping method is proposed by using harmonic content analysis. A generic function for the radial force shape is identified, whose parameters are calculated by an optimization algorithm to minimize the torque ripple for a given average torque. From the phase radial force profile, a current reference is obtained. The proposed methodology is experimentally validated with a four-phase 8/6 SRM through Acoustic Noise measurements at different speed and load conditions.
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hybrid Acoustic Noise analysis approach of conventional and mutually coupled switched reluctance motors
IEEE Transactions on Energy Conversion, 2017Co-Authors: Jianning Dong, Alan Dorneles Callegaro, Berker Bilgin, James Weisheng Jiang, Brock Howey, Ali EmadiAbstract:This paper presents a method to calculate the Acoustic Noise of conventional switched reluctance motor (CSRM) and mutually coupled switched reluctance motor (MCSRM). This method is based on dynamic electromagnetic models, combined with analytical estimation of the stator eigenmodes and radiation efficiency, considering the switching effects and frame effects. The proposed method is applied to predict and compare the Acoustic Noise performances of a CSRM and an MCSRM in a wide speed range. The results are validated using commercial finite element analysis software, JMAG for electromagnetics and ACTRAN for Acoustics. An acceleration test based on a setup with a 12/8 CSRM is used for experimental validation. Results show that the proposed method can provide reliable prediction of main Acoustic Noises during acceleration.
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Acoustic Noise analysis of a high speed high power switched reluctance machine frame effects
IEEE Transactions on Energy Conversion, 2016Co-Authors: Sandra M Castano, Berker Bilgin, Earl Fairall, Ali EmadiAbstract:This paper examines the effect of frame on the Acoustic Noise and vibration of a high-speed and high-power switched reluctance machine (SRM). Five types of frame/ribs are investigated, where different frame thicknesses, types of cooling ribs, and frame shapes have been analyzed. For this purpose, a 12/8 SRM has been designed at 22 000 r/min and 150 kW and two stages have been applied. In the first stage, a new equivalent stiffness of the frame is utilized in order to estimate the resonant frequencies for different frame shapes. The paper provides a mathematical calculation method and evaluates its effectiveness with finite-element simulations. The results indicate an improvement between 4% and 25% in the estimation natural frequencies. The second stage includes the vibration and Acoustic Noise analysis using 3-D finite-element method. Considerations for Acoustic Noise reduction in high-speed SRM using different frame types and cooling ribs are discussed. Particularly, radial and screw-type configurations represent a better solution to decrease the sound pressure level up to 12 dB.
