IEEE Transactions on Magnetics最新文献_第9页

MRAM-Based CiM Architecture for Backpropagation-Free Training of Neural Networks Using DFA and DRTP 基于mram的基于DFA和DRTP的神经网络无反向传播训练CiM体系

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-06-17 DOI: 10.1109/TMAG.2026.3704393

Hemkant Nehete;Amit Monga;Sandeep Soni;Tharun Kumar Reddy Bollu;Balasubramanian Raman

{"title":"MRAM-Based CiM Architecture for Backpropagation-Free Training of Neural Networks Using DFA and DRTP","authors":"Hemkant Nehete;Amit Monga;Sandeep Soni;Tharun Kumar Reddy Bollu;Balasubramanian Raman","doi":"10.1109/TMAG.2026.3704393","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3704393","url":null,"abstract":"Conventional backpropagation’s (BP) sequential nature limits its efficiency on compute-in-memory (CiM) architectures. To address this challenge, this work proposes the first CiM accelerator framework for training neural networks using direct feedback alignment (DFA) and direct random target propagation (DRTP) implemented on magnetoresistive random access memory (MRAM)-based CiM crossbars. By exploiting the inherent parallelism of these learning rules, the proposed design enables concurrent error propagation and weight-gradient computation for all layers. A CiM-aware mapping strategy is developed for forward computation, error projection, and gradient evaluation on crossbar arrays, along with hierarchical organization and pipelining to improve hardware utilization. The architecture is evaluated across fully connected and convolutional neural networks. Results show an average of 36% and 50% improvement in area and energy efficiency compared to BP-based training, while pipelining further reduces iteration latency and improves throughput. In particular, DRTP enables inter-iteration pipelining and achieves more than 100% higher throughput than BP in spin-orbit torque (SOT)-MRAM-based CiM architectures, demonstrating an efficient approach for scalable and energy-efficient on-chip neural network training.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"3401007-3401007"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Coil-Embedded Beacon Pole for 3-D Localization of Surrounding Magnetic Flux Sensors 一种用于周边磁通传感器三维定位的线圈嵌入信标杆

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-03-11 DOI: 10.1109/TMAG.2026.3692124

Yoshiaki Adachi;Takato Fukui;Daisuke Oyama;Tomohiko Shibuya

{"title":"A Coil-Embedded Beacon Pole for 3-D Localization of Surrounding Magnetic Flux Sensors","authors":"Yoshiaki Adachi;Takato Fukui;Daisuke Oyama;Tomohiko Shibuya","doi":"10.1109/TMAG.2026.3692124","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3692124","url":null,"abstract":"In this study, we propose a novel 3-D localization method using a coil-embedded beacon pole and magnetoresistive-device-based magnetic flux sensors (MR sensors) aimed at underwater applications. The beacon pole is constructed by stacking multiple cylindrical modules, each containing three elliptic coils embedded in grooves on its side surface with mutually orthogonal plane normals. The coils are oriented at 54.74°. with respect to the cylinder axis and separated by 120°. in azimuth. By detecting the magnetic fields generated by the coils embedded in the pole, the magnetic sensors can determine their positions in axial, radial, and circumferential directions relative to the pole. Low-frequency (30.180 Hz) fields, which are advantageous for applications in water, are generated by the pole and can be detected by the MR sensors with a high signal-to-noise ratio. Numerical simulations indicated that, although the coils were discretely arranged at 120°. intervals in azimuth, the localization performance remained effectively axisymmetric. Uniform precision was achieved in all directions, and a localization uncertainty of approximately less than 2 mm was obtained within a 1 m-diameter region around the beacon pole. However, in practical experiments using a small-scale prototype of the beacon pole, the uncertainty was limited to better than 11 mm within a 0.6 m-diameter region, reflecting real-world measurement constraints. Real-time positioning of the magnetic sensor was successfully demonstrated, achieving position updates at approximately 20 Hz.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"4001105-4001105"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11514085","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization Analysis of Core Loss and Rotor Eddy Current Loss in an Aircraft Excitation Built-in Hybrid Excitation Brushless Machine 飞机励磁内置混合励磁无刷电机铁心损耗和转子涡流损耗的优化分析

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-03-25 DOI: 10.1109/TMAG.2026.3696445

Longxin Du;Zhuoran Zhang;Chen Wang

引用次数: 0

In Situ Grain-Boundary Diffusion in Near-Equilibrium Nd-Fe-B Powders for High-Coercivity Reprocessed Magnets 高矫顽力再加工磁体近平衡态Nd-Fe-B粉末的原位晶界扩散

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-06-24 DOI: 10.1109/TMAG.2026.3706805

Tomaž Tomše;Fabian Burkhardt;Zoran Samardžija;Kristina Žužek

{"title":"In Situ Grain-Boundary Diffusion in Near-Equilibrium Nd-Fe-B Powders for High-Coercivity Reprocessed Magnets","authors":"Tomaž Tomše;Fabian Burkhardt;Zoran Samardžija;Kristina Žužek","doi":"10.1109/TMAG.2026.3706805","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3706805","url":null,"abstract":"We demonstrate an in situ grain-boundary diffusion strategy for enhancing the coercivity of reprocessed Nd-Fe-B magnets using near-equilibrium powder particles produced by intergranular fragmentation. A small addition (1 wt.%) of TbH3 leads to Tb enrichment at grain-boundary/shell regions, consistent with the formation of Tb-enriched shell-like regions around Nd2Fe14B grains during liquid-phase sintering. The resulting increase in the anisotropy field at grain surfaces raises the intrinsic coercivity by <inline-formula> <tex-math>$approx 35$ </tex-math></inline-formula>% (to 1010 kA/m at <inline-formula> <tex-math>$50~^{circ }$ </tex-math></inline-formula>C), exceeding that of the original magnet while preserving high remanence (1.41 T). The limited grain growth, corresponding to a growth factor of <inline-formula> <tex-math>$approx 1.23$ </tex-math></inline-formula>, suggests that extensive liquid-film migration is not dominant under the present conditions, in contrast to conventional grain-boundary diffusion processing. These results demonstrate that combining controlled powder preparation with in situ grain-boundary diffusion provides a scalable pathway for recovering and enhancing the performance of Nd-Fe-B magnets in HPMS-based short-loop recycling routes using minimal additions of heavy rare-earth elements.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"2101405-2101405"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11578122","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Novel Vertical-Axis Phase-Synchronous Pulse-Injection Sensorless Control Based on Three-Phase Four-Leg Drive for Hybrid-Excited Variable Reluctance Machine 基于三相四足驱动的新型混合励磁变磁阻电机垂直轴相同步脉冲注入无传感器控制

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-04-28 DOI: 10.1109/TMAG.2026.3687900

Jifu Jiang;Xin Li;Keliang Zhou;Shuangxia Niu;Wang Weiyu

{"title":"A Novel Vertical-Axis Phase-Synchronous Pulse-Injection Sensorless Control Based on Three-Phase Four-Leg Drive for Hybrid-Excited Variable Reluctance Machine","authors":"Jifu Jiang;Xin Li;Keliang Zhou;Shuangxia Niu;Wang Weiyu","doi":"10.1109/TMAG.2026.3687900","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3687900","url":null,"abstract":"This article investigates a novel sensorless control strategy for a hybrid-excited variable reluctance machine (HE-VRM) with integrated windings and double-layer stator-slot permanent magnets, which can facilitate its application in safety-critical systems. In the traditional three-phase inverter structure, the phase inductance remains constant due to complementary characteristics, which is not conducive to sensorless control. In this case, a novel set of drives constructed by two three-phase four-leg inverters is proposed to divide the phase inductance into two groups for separate control. Subsequently, a self-inductance model is established, and the pulse-injection method is integrated to measure the real-time self-inductance. Considering that the mutual inductance between vertical-axis phase inductances is negligible, a novel vertical-axis phase synchronous pulse injection method is proposed. Compared with the full-phase pulse injection method, this method halves the number of detection pulses, which saves calculation time. Simulation experiments are implemented via the co-simulation of Ansys and MATLAB. The final analysis of the simulation results demonstrates that the vertical-axis phase-synchronous pulse-injection method can improve detection accuracy and acceleration performance.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"8202405-8202405"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Comparative Study of Flux Reversal Motors With Different Permanent Magnet Arrangements 不同永磁体结构磁通反转电机的比较研究

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-03-20 DOI: 10.1109/TMAG.2026.3695153

Shotaro Tsunoda;Kenji Nakamura

{"title":"A Comparative Study of Flux Reversal Motors With Different Permanent Magnet Arrangements","authors":"Shotaro Tsunoda;Kenji Nakamura","doi":"10.1109/TMAG.2026.3695153","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3695153","url":null,"abstract":"A flux reversal motor (FRM) is a type of doubly salient permanent magnet (PM) synchronous machine. Owing to the rotor composed entirely of a laminated core, the FRM offers superior mechanical robustness compared to conventional surface PM (SPM) motors. Therefore, FRMs have attracted attention in recent years. This article presents a comparative investigation of two PM arrangements in an FRM. The first is the conventional NSSN sequence reported in previous studies, while the second is a newly proposed NSNS sequence. The flux flows in the motor of both configurations are systematically analyzed. In particular, the flux flows created by the PMs and armature current are clarified based on magnetic equivalent circuit theory, and the differences in flux density distributions resulting from their superposition are examined. It is shown that these differences lead to distinct magnetic saturation characteristics under high-current-density conditions. Furthermore, the influence of the different flux waveforms on iron loss is evaluated. The results demonstrate that the proposed NSNS array achieves improved torque performance in the high-currentdensity region by mitigating magnetic saturation through a unique flux cancellation mechanism. Moreover, it is revealed that the proposed NSNS array reduces total iron loss and enhances efficiency, as the reduction in flux density amplitude outweighs the impact of the increased spatial frequency. These findings provide design insights into the selection of magnet arrangements for high-performance FRMs.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"8203205-8203205"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149250370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Precision Levitation Control of a Planar Motor via Compensation of FEM–Hardware Electromagnetic Discrepancies 基于fem -硬件电磁差异补偿的平面电机精密悬浮控制

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-03-01 DOI: 10.1109/TMAG.2026.3689707

Keigo Nakata;Wataru Ohnishi;Takafumi Koseki;Yuichiro Nakamura;Kenji Takahashi;Hiroyuki Sekiguchi

引用次数: 0

Enhancement of Magnetic Properties in (Sm, Dy, Gd, Er)(Co, Fe, Cu, Zr)z Magnets by Prolonging the Drying Time of Ball-Milled Powders 延长球磨粉干燥时间对（Sm, Dy, Gd, Er）（Co, Fe, Cu, Zr）z磁体磁性能的影响

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-08-17 DOI: 10.1109/TMAG.2026.3724497

Chunguo Wang;Bo Zhou;Xiaoxiao Zhang;Zhiqi Wang;Chaozhong Wang;Xinteng Shen;Lei Liu;Yingli Sun;Yong Ding;Aru Yan

{"title":"Enhancement of Magnetic Properties in (Sm, Dy, Gd, Er)(Co, Fe, Cu, Zr)z Magnets by Prolonging the Drying Time of Ball-Milled Powders","authors":"Chunguo Wang;Bo Zhou;Xiaoxiao Zhang;Zhiqi Wang;Chaozhong Wang;Xinteng Shen;Lei Liu;Yingli Sun;Yong Ding;Aru Yan","doi":"10.1109/TMAG.2026.3724497","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3724497","url":null,"abstract":"Doping of heavy rare Earth elements (HREs) in Sm2Co17 permanent magnets demonstrates a significant potential for reducing remanence temperature coefficient, thereby improving the precision of magnetic instruments with temperature variation. However, such alloying additions tend to compromise magnetic performance. This study aims to improve the magnetic properties by ball milling process optimization in Sm2Co17 permanent magnets doped with Dy, Gd, and Er. Prolonging the drying time of ball-milled powders will increase the content of (Sm, Gd)2O3, therefore reducing the content of Sm in the matrix and a higher proportion of cell interiors. The increased cell interiors help improve remanence, which is increased from 8.612 to 8.798 kg at room temperature. On the other hand, enriched (Sm, Gd)2O3 precipitates may be strong domain pinning sites and are responsible for the coercivity enhancement, which is increased from 15.26 to >26.00 kOe at room temperature. Meanwhile, the thermal stability is also improved by prolonging drying time. The remanence temperature coefficient between <inline-formula> <tex-math>$20~^{circ }$ </tex-math></inline-formula>C and <inline-formula> <tex-math>$200~^{circ }$ </tex-math></inline-formula>C is slightly reduced from −0.0118%/°C to −0.0037%/°C. It is attributed to the increase in the proportion of HREs in the matrix, which is caused by more Sm being consumed by oxidation when compared with heavy rare Earth. This work provides a viable method for magnetic performance enhancement in Sm2Co17 permanent magnets with HREs doping.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"2101505-2101505"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149249265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Variable-Temperature Magnetic Properties Measurement and Improved Temperature-Coupled Bertotti Core-Loss Modeling of Fe-Based Amorphous Alloy 铁基非晶合金变温磁性能测量及改进的温度耦合Bertotti铁心损耗模型

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-03-25 DOI: 10.1109/TMAG.2026.3696280

Jialin Li;Yu Dou;Jiapeng Zhou;Shuaichao Yue;Tao Chen;Yongjian Li

{"title":"Variable-Temperature Magnetic Properties Measurement and Improved Temperature-Coupled Bertotti Core-Loss Modeling of Fe-Based Amorphous Alloy","authors":"Jialin Li;Yu Dou;Jiapeng Zhou;Shuaichao Yue;Tao Chen;Yongjian Li","doi":"10.1109/TMAG.2026.3696280","DOIUrl":"https://doi.org/10.1109/TMAG.2026.3696280","url":null,"abstract":"Fe-based amorphous alloys are important for medium- and high-frequency magnetic devices. This work investigates the variable-temperature magnetic properties and core loss of Fe-based amorphous ribbon strips and develops a temperature-coupled Bertotti (TCB) model for loss prediction under coupled frequency–temperature conditions. In this article, the magnetic properties and core loss of Fe-based amorphous alloy were measured from <inline-formula> <tex-math>$25~^{circ }$ </tex-math></inline-formula>C to <inline-formula> <tex-math>$100~^{circ }$ </tex-math></inline-formula>C and from 50 Hz to 3 kHz by the Epstein-frame method. The experimental results show that temperature significantly affects the magnetization and loss characteristics. With increasing temperature, the magnetization curve shifts rightward, the peak permeability increases, and the hysteresis-loop area as well as the total loss generally decreases. Based on the Bertotti loss-separation framework, a temperature-coupled core loss model is established, and temperature dependence is incorporated at the loss components. The accuracy and effectiveness of the proposed model are verified using experimental results under varying temperatures and a wide frequency range.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 10","pages":"6302906-6302906"},"PeriodicalIF":1.9,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149249278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analytical Modeling of HTS Single-Sided Linear Induction Motors for Rail Transportation Applications 轨道交通用高温超导单面直线感应电动机的解析建模

IF 1.9 3区工程技术

IEEE Transactions on Magnetics Pub Date : 2026-10-01 Epub Date: 2026-03-13 DOI: 10.1109/TMAG.2026.3692796

Wei Qin;Yujie Lu;Fang Jin;Wenliang Wang

引用次数: 0