Pub Date : 2024-11-14DOI: 10.1109/TMAG.2024.3498010
Hajime Igarashi;Qiao Liu;Shuli Yin
This article extends the Dowell method and the semi-analytical homogenization method to analyze copper losses in a magnetic device in the time domain. The main contribution of this work is that the impedances provided by the Dowell method and the complex permeability resulting from the homogenization method are represented by the continued fractions and corresponding Cauer equivalent circuits, with which the time-domain analysis can be effectively performed. The transient waveforms of the copper loss computed by the equivalent circuit, in which the original leakage inductance is extended to a Cauer circuit, are shown to be in good agreement with those computed by the finite element method. It is also shown that the Dowell method is valid only for the 1-D magnetic field over the winding region, while the homogenization method is valid even when this assumption does not hold.
{"title":"Extension of Dowell and Semi-Analytical Homogenization Methods for Time-Domain Analysis of Magnetic Devices","authors":"Hajime Igarashi;Qiao Liu;Shuli Yin","doi":"10.1109/TMAG.2024.3498010","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3498010","url":null,"abstract":"This article extends the Dowell method and the semi-analytical homogenization method to analyze copper losses in a magnetic device in the time domain. The main contribution of this work is that the impedances provided by the Dowell method and the complex permeability resulting from the homogenization method are represented by the continued fractions and corresponding Cauer equivalent circuits, with which the time-domain analysis can be effectively performed. The transient waveforms of the copper loss computed by the equivalent circuit, in which the original leakage inductance is extended to a Cauer circuit, are shown to be in good agreement with those computed by the finite element method. It is also shown that the Dowell method is valid only for the 1-D magnetic field over the winding region, while the homogenization method is valid even when this assumption does not hold.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-9"},"PeriodicalIF":2.1,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905700","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}
Pub Date : 2024-11-14DOI: 10.1109/TMAG.2024.3498098
Xiaotong Fu;Shuai Yan;Zhifu Chen;Zhuoxiang Ren
The calculation of the eddy current field in the motional scenario is a difficult problem. Due to the movement of conductors, the original mesh may be largely deformed. For engineering models with complex geometric shapes, re-meshing is a time-consuming task for each time step iteration. To avoid re-meshing, this article proposes a new method based on interface adaptation of overlapping non-conforming meshes. Without changing the topology of the background mesh, the invasion interface is transformed into a non-conforming interface between the moving parts, avoiding generating arbitrarily small or irregular cutting elements. Furthermore, the mortar technique is used to deal with the field computation involving a non-conforming interface.
{"title":"Computation of Movement Involved Eddy Current Field Using Interface Adaptation of Overlapping Mesh","authors":"Xiaotong Fu;Shuai Yan;Zhifu Chen;Zhuoxiang Ren","doi":"10.1109/TMAG.2024.3498098","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3498098","url":null,"abstract":"The calculation of the eddy current field in the motional scenario is a difficult problem. Due to the movement of conductors, the original mesh may be largely deformed. For engineering models with complex geometric shapes, re-meshing is a time-consuming task for each time step iteration. To avoid re-meshing, this article proposes a new method based on interface adaptation of overlapping non-conforming meshes. Without changing the topology of the background mesh, the invasion interface is transformed into a non-conforming interface between the moving parts, avoiding generating arbitrarily small or irregular cutting elements. Furthermore, the mortar technique is used to deal with the field computation involving a non-conforming interface.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-4"},"PeriodicalIF":2.1,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905807","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}
Pub Date : 2024-11-14DOI: 10.1109/TMAG.2024.3498051
Rongxiao Yan;Daohan Wang;Chengqi Wang;Wenqiang Miao;Xiuhe Wang
The sideband current harmonic components are inevitable in a permanent magnet synchronous motor (PMSM) drive system driven by a voltage-source inverter with space vector pulsewidth modulation (SVPWM). The research on the characteristics of sideband harmonic currents would provide guidance to the cause of electromagnetic force waves, vibration, and acoustic noise of the motor. In this article, the main components of sideband harmonic currents in PMSM drive by the SVPWM method are analytically derived. The frequency and spatial order of the sideband harmonics and radial electromagnetic force are calculated based on finite element analysis (FEA). Then, an experimental test of an eight-pole/48-slot interior PMSM with a voltage-source inverter controlled by the classical vector control strategy is carried out, and the phase stator currents, vibration response, and acoustic noise signals are collected. The results finally verify the accuracy of the derivation analysis of sideband currents and indicate the relation between sideband harmonic currents and electromagnetic vibration, which provides a reference for further studies of vibration suppression.
{"title":"Analytical Approach and Experimental Validation of Sideband Electromagnetic Vibration and Noise in PMSM Drive With Voltage-Source Inverter by SVPWM Technique","authors":"Rongxiao Yan;Daohan Wang;Chengqi Wang;Wenqiang Miao;Xiuhe Wang","doi":"10.1109/TMAG.2024.3498051","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3498051","url":null,"abstract":"The sideband current harmonic components are inevitable in a permanent magnet synchronous motor (PMSM) drive system driven by a voltage-source inverter with space vector pulsewidth modulation (SVPWM). The research on the characteristics of sideband harmonic currents would provide guidance to the cause of electromagnetic force waves, vibration, and acoustic noise of the motor. In this article, the main components of sideband harmonic currents in PMSM drive by the SVPWM method are analytically derived. The frequency and spatial order of the sideband harmonics and radial electromagnetic force are calculated based on finite element analysis (FEA). Then, an experimental test of an eight-pole/48-slot interior PMSM with a voltage-source inverter controlled by the classical vector control strategy is carried out, and the phase stator currents, vibration response, and acoustic noise signals are collected. The results finally verify the accuracy of the derivation analysis of sideband currents and indicate the relation between sideband harmonic currents and electromagnetic vibration, which provides a reference for further studies of vibration suppression.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-6"},"PeriodicalIF":2.1,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905724","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}
Pub Date : 2024-11-14DOI: 10.1109/TMAG.2024.3498593
Markus Clemens;Marvin-Lucas Henkel;Fotios Kasolis;Michael Günther
Electromagneto-quasistatic (EMQS) field formulations allow to model resistive, capacitive, and inductive field effects while neglecting wave propagation. These field formulations are based on the Darwin–Ampére equation and yield different approximations of the full set of Maxwell’s equations depending on the choice of additional equations. Various discrete EMQS formulations are analyzed using the port-Hamiltonian system framework. It is shown that several symmetric EMQS formulations, e.g., combinations of the Darwin–Ampére equation and the Maxwell continuity equation, yield port-Hamiltonian differential-algebraic equation (pH-DAE) systems, which implies their numerical stability, energy conservation related to a specific EMQS variant of the Hamiltonian and dissipativity results.
{"title":"Structural Aspects of Electromagneto-Quasistatic Field Formulations of Darwin-Type Derived in the Port-Hamiltonian System Framework","authors":"Markus Clemens;Marvin-Lucas Henkel;Fotios Kasolis;Michael Günther","doi":"10.1109/TMAG.2024.3498593","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3498593","url":null,"abstract":"Electromagneto-quasistatic (EMQS) field formulations allow to model resistive, capacitive, and inductive field effects while neglecting wave propagation. These field formulations are based on the Darwin–Ampére equation and yield different approximations of the full set of Maxwell’s equations depending on the choice of additional equations. Various discrete EMQS formulations are analyzed using the port-Hamiltonian system framework. It is shown that several symmetric EMQS formulations, e.g., combinations of the Darwin–Ampére equation and the Maxwell continuity equation, yield port-Hamiltonian differential-algebraic equation (pH-DAE) systems, which implies their numerical stability, energy conservation related to a specific EMQS variant of the Hamiltonian and dissipativity results.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-4"},"PeriodicalIF":2.1,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912495","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}
Insulated gate bipolar transistor (IGBT) is one of the most important power modules in electric traction converter systems. However, the IGBT module may suffer from alternating thermal load and frequent vibration impacts, which will cause crack damage and propagation in the solder layer, resulting in early failure. In this article, the 3-D extended finite element method (XFEM) is used to investigate the fatigue propagation characteristics of crack damage in the solder layer of an IGBT module, where the coupling effects of transient temperature and mechanical fields are considered. The thermal-vibration coupling relationship and periodic fatigue propagation of crack damage are analyzed by using XFEM. The distributions of stress, strain, and crack damage evolution state under different thermal-vibration loads are obtained. Based on the fracture mechanics theory and Paris equation, the dynamic crack propagation and damage fatigue evolution of the IGBT solder layer under periodic coupling stress are revealed. Results show that the thermal-vibration coupling effect causes the crack damage propagation of the IGBT solder layer and the change of crack damage fatigue propagation rate. The results of this research may contribute to the failure mechanism and fatigue life prediction of high-power module IGBT devices.
{"title":"Fatigue Propagation Analysis of Crack Failure in High-Power IGBT Solder Based on Multiphysics Coupling Model and XFEM","authors":"Haijun Zhang;Jiashun Wang;Haifeng Kong;Bangwei Zhang","doi":"10.1109/TMAG.2024.3496913","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3496913","url":null,"abstract":"Insulated gate bipolar transistor (IGBT) is one of the most important power modules in electric traction converter systems. However, the IGBT module may suffer from alternating thermal load and frequent vibration impacts, which will cause crack damage and propagation in the solder layer, resulting in early failure. In this article, the 3-D extended finite element method (XFEM) is used to investigate the fatigue propagation characteristics of crack damage in the solder layer of an IGBT module, where the coupling effects of transient temperature and mechanical fields are considered. The thermal-vibration coupling relationship and periodic fatigue propagation of crack damage are analyzed by using XFEM. The distributions of stress, strain, and crack damage evolution state under different thermal-vibration loads are obtained. Based on the fracture mechanics theory and Paris equation, the dynamic crack propagation and damage fatigue evolution of the IGBT solder layer under periodic coupling stress are revealed. Results show that the thermal-vibration coupling effect causes the crack damage propagation of the IGBT solder layer and the change of crack damage fatigue propagation rate. The results of this research may contribute to the failure mechanism and fatigue life prediction of high-power module IGBT devices.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-4"},"PeriodicalIF":2.1,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912575","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}
Pub Date : 2024-11-12DOI: 10.1109/TMAG.2024.3496719
Minhee Kim;Yong Sung Cho
The increase in renewable energy and the development of silicon carbide (SiC) and gallium nitride (GaN) power switches have led to higher voltage magnitudes, slew rates, and switching frequencies, imposing greater electric stress on insulating materials. However, it is hard to recognize the partial discharge (PD) signal from background noise due to electromagnetic interference when diagnosing electrical equipment with high switching frequency. Therefore, we numerically analyzed negative corona discharge under a superposition of direct current (dc) and pulsewidth modulation (PWM) voltage, with a switching frequency of 80 kHz in a needle-plane geometry varying rising times of 100, 200, and 500 ns. The analysis model was coupled with Poisson’s equation and the drift-diffusion model. We considered three types of charge carriers—electrons, positive ions, and negative ions—and the generation and loss of each charge carrier. The discharge current was calculated from Poynting’s theorem. The discharge current pulses were regularly sustained, like the Trichel pulses in the previous research. However, the periods between pulses and the magnitude of the pulses changed depending on the applied voltage and rising time. With the increase in rising time, both the current pulse peak value and the pulse period decreased, affecting the charge distribution, especially for the ionization region and negative ions.
{"title":"Numerical Analysis for Negative Discharge Under High-Frequency Pulsed Voltage","authors":"Minhee Kim;Yong Sung Cho","doi":"10.1109/TMAG.2024.3496719","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3496719","url":null,"abstract":"The increase in renewable energy and the development of silicon carbide (SiC) and gallium nitride (GaN) power switches have led to higher voltage magnitudes, slew rates, and switching frequencies, imposing greater electric stress on insulating materials. However, it is hard to recognize the partial discharge (PD) signal from background noise due to electromagnetic interference when diagnosing electrical equipment with high switching frequency. Therefore, we numerically analyzed negative corona discharge under a superposition of direct current (dc) and pulsewidth modulation (PWM) voltage, with a switching frequency of 80 kHz in a needle-plane geometry varying rising times of 100, 200, and 500 ns. The analysis model was coupled with Poisson’s equation and the drift-diffusion model. We considered three types of charge carriers—electrons, positive ions, and negative ions—and the generation and loss of each charge carrier. The discharge current was calculated from Poynting’s theorem. The discharge current pulses were regularly sustained, like the Trichel pulses in the previous research. However, the periods between pulses and the magnitude of the pulses changed depending on the applied voltage and rising time. With the increase in rising time, both the current pulse peak value and the pulse period decreased, affecting the charge distribution, especially for the ionization region and negative ions.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-4"},"PeriodicalIF":2.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905723","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}
Pub Date : 2024-11-12DOI: 10.1109/TMAG.2024.3496695
Abhishek Chandra;Bram Daniels;Mitrofan Curti;Koen Tiels;Elena A. Lomonova
Hysteresis modeling is crucial to comprehend the behavior of magnetic devices, facilitating optimal designs. Hitherto, deep learning-based methods employed to model hysteresis face challenges in generalizing to novel input magnetic fields. This article addresses the generalization challenge by proposing neural operators for modeling constitutive laws that exhibit magnetic hysteresis by learning a mapping between magnetic fields. In particular, three neural operators—deep operator network (DeepONet), Fourier neural operator (FNO), and wavelet neural operator (WNO)—are employed to predict novel first-order reversal curves and minor loops, where novel means that they are not used to train the model. In addition, a rate-independent FNO is proposed to predict material responses at sampling rates different from those used during training to incorporate the rate-independent characteristics of magnetic hysteresis. The presented numerical experiments demonstrate that neural operators efficiently model magnetic hysteresis, outperforming the traditional neural recurrent methods on various metrics and generalizing to novel magnetic fields. The findings emphasize the advantages of using neural operators for modeling hysteresis under varying magnetic conditions, underscoring their importance in characterizing magnetic material-based devices. The codes related to this article are available at https://github.com/chandratue/magnetic_hysteresis_neural_operator .
{"title":"Magnetic Hysteresis Modeling With Neural Operators","authors":"Abhishek Chandra;Bram Daniels;Mitrofan Curti;Koen Tiels;Elena A. Lomonova","doi":"10.1109/TMAG.2024.3496695","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3496695","url":null,"abstract":"Hysteresis modeling is crucial to comprehend the behavior of magnetic devices, facilitating optimal designs. Hitherto, deep learning-based methods employed to model hysteresis face challenges in generalizing to novel input magnetic fields. This article addresses the generalization challenge by proposing neural operators for modeling constitutive laws that exhibit magnetic hysteresis by learning a mapping between magnetic fields. In particular, three neural operators—deep operator network (DeepONet), Fourier neural operator (FNO), and wavelet neural operator (WNO)—are employed to predict novel first-order reversal curves and minor loops, where novel means that they are not used to train the model. In addition, a rate-independent FNO is proposed to predict material responses at sampling rates different from those used during training to incorporate the rate-independent characteristics of magnetic hysteresis. The presented numerical experiments demonstrate that neural operators efficiently model magnetic hysteresis, outperforming the traditional neural recurrent methods on various metrics and generalizing to novel magnetic fields. The findings emphasize the advantages of using neural operators for modeling hysteresis under varying magnetic conditions, underscoring their importance in characterizing magnetic material-based devices. The codes related to this article are available at \u0000<uri>https://github.com/chandratue/magnetic_hysteresis_neural_operator</uri>\u0000.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-11"},"PeriodicalIF":2.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912568","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}
Pub Date : 2024-11-11DOI: 10.1109/TMAG.2024.3495025
Meenakshi Sravani;Swapnil Bhuktare
The synchronization behavior of two spin torque nano oscillators (STNOs) with second-order anisotropy, connected via parallel coupling, has been studied in the presence of the thermal field. The second-order anisotropy led to the biasing of the free layer (FL) of both the STNOs in the easy cone regime called the conical FL (CFL). This parallel coupling facilitated frequency and in-phase synchronization between the two STNOs without the need for any external field. The simulation results demonstrating this in-phase synchronization have been supported by analytical theory. Further, the effects of parallel coupling on oscillation parameters, such as frequency, power, and linewidth, have been examined. The variation of the frequency with current and the coupling factor has been derived using the LLGS equation. The study achieved a threefold increase in output power and a reduction in linewidth to the order of kHz, without requiring an external field. These advancements highlight the potential of the device for reliable practical applications.
{"title":"Field-Free Mutual Synchronization of Parallel Coupled Spin Torque Nano Oscillators Using a Free Layer With First- and Second-Order Uniaxial Anisotropy","authors":"Meenakshi Sravani;Swapnil Bhuktare","doi":"10.1109/TMAG.2024.3495025","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3495025","url":null,"abstract":"The synchronization behavior of two spin torque nano oscillators (STNOs) with second-order anisotropy, connected via parallel coupling, has been studied in the presence of the thermal field. The second-order anisotropy led to the biasing of the free layer (FL) of both the STNOs in the easy cone regime called the conical FL (CFL). This parallel coupling facilitated frequency and in-phase synchronization between the two STNOs without the need for any external field. The simulation results demonstrating this in-phase synchronization have been supported by analytical theory. Further, the effects of parallel coupling on oscillation parameters, such as frequency, power, and linewidth, have been examined. The variation of the frequency with current and the coupling factor has been derived using the LLGS equation. The study achieved a threefold increase in output power and a reduction in linewidth to the order of kHz, without requiring an external field. These advancements highlight the potential of the device for reliable practical applications.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-7"},"PeriodicalIF":2.1,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912475","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}
Multilaminated thin-film inductors are a key to emerging technology that enables highly integrated, on-chip voltage regulators. The permeability of a magnetic core at high frequency is a key determiner of inductance density. In this article, a multilamination magnetic core made up of alternate CoZrTaB (CZTB) amorphous, uniaxially anisotropic magnetic films and AlN dielectric layers is investigated. The individual films are approximately 200 nm thick, appropriate for operation at over 100 MHz, but the laminated structure and overall thickness of several micrometers mean that analytical methods are impractical for computing demagnetization. Magnetostatic finite element analysis (FEAs) is used to model the magnetic core demagnetization, accounting for various length/width dimensions, magnetic film thicknesses, and dielectric thicknesses. At higher frequencies, the dielectric layers, which are included in the structure to suppress induced eddy currents, allow displacement currents to flowthrough the dielectric layers and lead to increased eddy currents circulating around the overall core structure, thus further increasing loss and reducing permeability. Eddy current FEA simulations, which include the displacement currents and an analytically derived equivalent circuit model (ECM), are used to model the real and imaginary (loss) components of permeability spectra. The work, therefore, determines the combined contributions of both demagnetization effects and eddy displacement currents to the reductions in real permeability and the increase in loss components for thicker multilaminated magnetic cores. Permeameter measurements on fabricated cores, having ten laminations, and with various AlN thicknesses (10, 20, 40, and 60 nm) gave excellent agreement with the predicted effective permeability through the approach of combining the FEA and ECM models, over the 10 MHz to 1 GHz frequency range. It was shown, that at 100 MHz, for multilaminated cores with thin or higher k dielectric layers, displacement-eddy currents are dominant, giving a power loss an order of magnitude higher than would be for magnetically induced eddy currents alone.
{"title":"Determining the Effective Permeability of a Laminated CoZrTaB (CZTB) Film Through Consideration of Demagnetization Effects and Eddy-Displacement Currents","authors":"Ruaidhrí Murphy;Guannan Wei;Ansar Masood;Cian O’Mathúna;Zoran Pavlovic;Paul McCloskey;Séamus O’Driscoll","doi":"10.1109/TMAG.2024.3494675","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3494675","url":null,"abstract":"Multilaminated thin-film inductors are a key to emerging technology that enables highly integrated, on-chip voltage regulators. The permeability of a magnetic core at high frequency is a key determiner of inductance density. In this article, a multilamination magnetic core made up of alternate CoZrTaB (CZTB) amorphous, uniaxially anisotropic magnetic films and AlN dielectric layers is investigated. The individual films are approximately 200 nm thick, appropriate for operation at over 100 MHz, but the laminated structure and overall thickness of several micrometers mean that analytical methods are impractical for computing demagnetization. Magnetostatic finite element analysis (FEAs) is used to model the magnetic core demagnetization, accounting for various length/width dimensions, magnetic film thicknesses, and dielectric thicknesses. At higher frequencies, the dielectric layers, which are included in the structure to suppress induced eddy currents, allow displacement currents to flowthrough the dielectric layers and lead to increased eddy currents circulating around the overall core structure, thus further increasing loss and reducing permeability. Eddy current FEA simulations, which include the displacement currents and an analytically derived equivalent circuit model (ECM), are used to model the real and imaginary (loss) components of permeability spectra. The work, therefore, determines the combined contributions of both demagnetization effects and eddy displacement currents to the reductions in real permeability and the increase in loss components for thicker multilaminated magnetic cores. Permeameter measurements on fabricated cores, having ten laminations, and with various AlN thicknesses (10, 20, 40, and 60 nm) gave excellent agreement with the predicted effective permeability through the approach of combining the FEA and ECM models, over the 10 MHz to 1 GHz frequency range. It was shown, that at 100 MHz, for multilaminated cores with thin or higher k dielectric layers, displacement-eddy currents are dominant, giving a power loss an order of magnitude higher than would be for magnetically induced eddy currents alone.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-10"},"PeriodicalIF":2.1,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912473","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}
Pub Date : 2024-11-08DOI: 10.1109/TMAG.2024.3494534
Kyungseon Cho;Yeongkyo Seo
This article proposes a hybrid spin-complementary metal–oxide–semiconductor (CMOS) logic design based on cascadable spin-torque majority gate (STMG), which allows the implementation of multiple STMG logic stages for very large-scale integration circuits by addressing the cascading and fan-out issues encountered in conventional STMGs. In conventional STMG-based logic circuits, excessive current flow occurs owing to simultaneous majority-gate operation across all stages, which may degrade the reliability of domain walls. In contrast, the cascadable STMG (C-STMG), composed of an STMG device and transistors, enables sequential majority gate operations at only selected stages. Furthermore, C-STMG circuits can be segmented into finer stages, enabling fine-grained pipelining, thereby achieving a higher throughput than conventional STMG. Additionally, this article presents a method for designing a 16-bit full-adder (FA) circuit using C-STMG. After the design and verification of the 16-bit C-STMG FA, 32-bit and 64-bit C-STMG FAs are designed, and all configurations are compared with the corresponding CMOS FAs under the same conditions. The C-STMG FAs achieve over 28% improvement in the energy compared with CMOS FAs. Moreover, the improvement in energy consumption is more significant at smaller activity ratios because C-STMG circuits exhibit almost-zero leakage power consumption owing to their non-volatility. In particular, the 64-bit C-STMG FA achieves 76.8% lower-energy dissipation at activity ratios of 1% compared with the corresponding CMOS FA.
{"title":"Energy-Efficient Hybrid Spin-CMOS Logic Design Based on Cascadable Spin-Torque Majority Gate","authors":"Kyungseon Cho;Yeongkyo Seo","doi":"10.1109/TMAG.2024.3494534","DOIUrl":"https://doi.org/10.1109/TMAG.2024.3494534","url":null,"abstract":"This article proposes a hybrid spin-complementary metal–oxide–semiconductor (CMOS) logic design based on cascadable spin-torque majority gate (STMG), which allows the implementation of multiple STMG logic stages for very large-scale integration circuits by addressing the cascading and fan-out issues encountered in conventional STMGs. In conventional STMG-based logic circuits, excessive current flow occurs owing to simultaneous majority-gate operation across all stages, which may degrade the reliability of domain walls. In contrast, the cascadable STMG (C-STMG), composed of an STMG device and transistors, enables sequential majority gate operations at only selected stages. Furthermore, C-STMG circuits can be segmented into finer stages, enabling fine-grained pipelining, thereby achieving a higher throughput than conventional STMG. Additionally, this article presents a method for designing a 16-bit full-adder (FA) circuit using C-STMG. After the design and verification of the 16-bit C-STMG FA, 32-bit and 64-bit C-STMG FAs are designed, and all configurations are compared with the corresponding CMOS FAs under the same conditions. The C-STMG FAs achieve over 28% improvement in the energy compared with CMOS FAs. Moreover, the improvement in energy consumption is more significant at smaller activity ratios because C-STMG circuits exhibit almost-zero leakage power consumption owing to their non-volatility. In particular, the 64-bit C-STMG FA achieves 76.8% lower-energy dissipation at activity ratios of 1% compared with the corresponding CMOS FA.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"61 1","pages":"1-8"},"PeriodicalIF":2.1,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912401","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}
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