Mohammad Mushfiqur Rahman, Arbaaz Khan, D. Lowther, D. Giannacopoulos
{"title":"Evaluating magnetic fields using deep learning","authors":"Mohammad Mushfiqur Rahman, Arbaaz Khan, D. Lowther, D. Giannacopoulos","doi":"10.1108/compel-12-2022-0436","DOIUrl":"https://doi.org/10.1108/compel-12-2022-0436","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to develop surrogate models, using deep learning (DL), that can facilitate the application of EM analysis software. In the current status quo, electrical systems can be found in an ever-increasing range of products that are part of everyone’s daily live. With the advances in technology, industries such as the automotive, communications and medical devices have been disrupted with new electrical and electronic systems. The innovation and development of such systems with increasing complexity over time has been supported by the increased use of electromagnetic (EM) analysis software. Such software enables engineers to virtually design, analyze and optimize EM systems without the need for building physical prototypes, thus helping to shorten the development cycles and consequently cut costs.\u0000\u0000\u0000Design/methodology/approach\u0000The industry standard for simulating EM problems is using either the finite difference method or the finite element method (FEM). Optimization of the design process using such methods requires significant computational resources and time. With the emergence of artificial intelligence, along with specialized tools for automatic differentiation, the use of DL has become computationally much more efficient and cheaper. These advances in machine learning have ushered in a new era in EM simulations where engineers can compute results much faster while maintaining a certain level of accuracy.\u0000\u0000\u0000Findings\u0000This paper proposed two different models that can compute the magnetic field distribution in EM systems. The first model is based on a recurrent neural network, which is trained through a data-driven supervised learning method. The second model is an extension to the first with the incorporation of additional physics-based information to the authors’ model. Such a DL model, which is constrained by the laws of physics, is known as a physics-informed neural network. The solutions when compared with the ground truth, computed using FEM, show promising accuracy for the authors’ DL models while reducing the computation time and resources required, as compared to previous implementations in the literature.\u0000\u0000\u0000Originality/value\u0000The paper proposes a neural network architecture and is trained with two different learning methodologies, namely, supervised and physics-based. The working of the network along with the different learning methodologies is validated over several EM problems with varying levels of complexity. Furthermore, a comparative study is performed regarding performance accuracy and computational cost to establish the efficacy of different architectures and learning methodologies.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"144 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82905213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Topology optimization and parameter optimization hybridized by mesh smoothing for IPMSM design","authors":"Zhen Sun, Takahiro Sato, Kota Watanabe","doi":"10.1108/compel-12-2022-0426","DOIUrl":"https://doi.org/10.1108/compel-12-2022-0426","url":null,"abstract":"\u0000Purpose\u0000Topology optimization (TO) methods have shown their unique advantage in the innovative design of electric machines. However, when introducing the TO method to the rotor design of interior permanent magnet (PM) synchronous machines (IPMSMs), the layout parameters of the magnet cannot be synchronously optimized with the topology of the air barrier; the full design potential, thus, cannot be unlocked. The purpose of this paper is to develop a novel method in which the layout parameters PMs and the topology of air barriers can be optimized simultaneously for aiding the innovative design of IPMSMs.\u0000\u0000\u0000Design/methodology/approach\u0000This paper presents a simultaneous TO and parameter optimization (PO) method that is applicable to the innovative design of IPMSMs. In this method, the mesh deformation technique is introduced to make it possible to make a connection between the TO and PO, and the multimodal optimization problem can thereby be solved more efficiently because good topological features are inherited during iterative optimization.\u0000\u0000\u0000Findings\u0000The numerical results of two case studies show that the proposed method can find better Pareto fronts than the traditional TO method within comparable time-consuming. As the optimal design result, novel rotor structures with better torque profiles and higher reluctance torque are respectively found.\u0000\u0000\u0000Originality/value\u0000A method that can simultaneously optimize the topology and parameter variables for the design of IPMSMs is proposed. The numerical results show that the proposed method is useful and practical for the conceptual and innovative design of IPMSMs because it can automatically explore optimal rotor structures from the full design space without relying on the experience and knowledge of the engineer.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"47 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79920559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thermal analysis for foreign objects in high-power wireless power transfer systems","authors":"M. Tiemann, M. Clemens, B. Schmuelling","doi":"10.1108/compel-01-2023-0022","DOIUrl":"https://doi.org/10.1108/compel-01-2023-0022","url":null,"abstract":"\u0000Purpose\u0000This paper aims to present a fast and modular framework implementation for the thermal analyses of foreign metal objects in the context of wireless power transfer (WPT) to evaluate whether they pose a hazard to the system. This framework serves as a decision-making tool for determining the necessity of foreign object detection in certain applications and at certain transmitted power levels.\u0000\u0000\u0000Design/methodology/approach\u0000To assess the necessity of implementing foreign object detection, the considered WPT system is modeled, and Arnoldi-Krylov-based model order reduction is applied to generate separate reduced models of the ground and vehicle modules of the WPT system. This enables interoperable evaluations to be conducted. Further discussion on the implementation details of the system-level simulations used to evaluate the electrical and thermal characteristics is provided. The resulting modular implementation allows for efficient evaluation of the thermal behavior of the wireless charging system at various transferred power levels and under various boundary conditions.\u0000\u0000\u0000Findings\u0000Based on the transferred power level, the WPT model, the relative positioning between the vehicle and the charging pad and the charging time, it may be necessary to divide the area of the charging pad into multiple regions for the purpose of implementing foreign object detection.\u0000\u0000\u0000Originality/value\u0000While the tools and fundamentals of thermal analysis are widely known and used, their application to high-power WPT systems for electric vehicles has not yet been thoroughly discussed in this form in the literature. The approach presented in this paper is not limited to the specific WPT model discussed but rather is directly applicable to other WPT models as well.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"195 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79823139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chong Xu, Penbo Wang, Fan Yang, Shaohua Wang, Junping Cao, Xin Wang
{"title":"A plasma energy deposition based model for power cable bellows discharge","authors":"Chong Xu, Penbo Wang, Fan Yang, Shaohua Wang, Junping Cao, Xin Wang","doi":"10.1108/compel-02-2023-0054","DOIUrl":"https://doi.org/10.1108/compel-02-2023-0054","url":null,"abstract":"\u0000Purpose\u0000This paper aims at building a discharge model for the power cable bellows based on plasma energy deposition and analyzing the discharge ablation problem.\u0000\u0000\u0000Design/methodology/approach\u0000Aiming at the multiphysical mechanism of the discharge ablation process, a multiphysical field model based on plasma energy deposition is established to analyze the discharge characteristics of the power cable bellows. The electrostatic field, plasma characteristics, energy deposition and temperature field are analyzed. The discharge experiment is also carried out for result validation.\u0000\u0000\u0000Findings\u0000The physical mechanism of the bellows ablative effect caused by partial discharge is studied. The results show that the electric field intensity between the aluminum sheath and the buffer layer easily exceeds the pressure resistance value of air breakdown. On the plasma surface of the buffer layer, the electron density is about 4 × 1,019/m3, and the average temperature of electrons is about 3.5 eV. The energy deposition analysis using the Monte Carlo method shows that the electron range in the plasma is very short. The release will complete within 10 nm, and it only takes 0.1 s to increase the maximum temperature of the buffer layer to more than 1,000 K, thus causing various thermal effects.\u0000\u0000\u0000Originality/value\u0000Its physical process involves the distortion of electric field, formation of plasma, energy deposition of electrons, and abrupt change of temperature field.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"36 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91239028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Neumayer, T. Suppan, T. Bretterklieber, H. Wegleiter, C. Fox
{"title":"Fast numerical techniques for FE simulations in electrical capacitance tomography","authors":"M. Neumayer, T. Suppan, T. Bretterklieber, H. Wegleiter, C. Fox","doi":"10.1108/compel-01-2023-0017","DOIUrl":"https://doi.org/10.1108/compel-01-2023-0017","url":null,"abstract":"\u0000Purpose\u0000Nonlinear solution approaches for inverse problems require fast simulation techniques for the underlying sensing problem. In this work, the authors investigate finite element (FE) based sensor simulations for the inverse problem of electrical capacitance tomography. Two known computational bottlenecks are the assembly of the FE equation system as well as the computation of the Jacobian. Here, existing computation techniques like adjoint field approaches require additional simulations. This paper aims to present fast numerical techniques for the sensor simulation and computations with the Jacobian matrix.\u0000\u0000\u0000Design/methodology/approach\u0000For the FE equation system, a solution strategy based on Green’s functions is derived. Its relation to the solution of a standard FE formulation is discussed. A fast stiffness matrix assembly based on an eigenvector decomposition is shown. Based on the properties of the Green’s functions, Jacobian operations are derived, which allow the computation of matrix vector products with the Jacobian for free, i.e. no additional solves are required. This is demonstrated by a Broyden–Fletcher–Goldfarb–Shanno-based image reconstruction algorithm.\u0000\u0000\u0000Findings\u0000MATLAB-based time measurements of the new methods show a significant acceleration for all calculation steps compared to reference implementations with standard methods. E.g. for the Jacobian operations, improvement factors of well over 100 could be found.\u0000\u0000\u0000Originality/value\u0000The paper shows new methods for solving known computational tasks for solving inverse problems. A particular advantage is the coherent derivation and elaboration of the results. The approaches can also be applicable to other inverse problems.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"144 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86200741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An improved on/off method with a two-step surface smoother for topology optimization of electromagnetic devices","authors":"Zhen Sun, Kota Watanabe","doi":"10.1108/compel-12-2022-0432","DOIUrl":"https://doi.org/10.1108/compel-12-2022-0432","url":null,"abstract":"\u0000Purpose\u0000Topology optimization is a state-of-the-art technique for the innovative design of electromagnetic devices. The ON/OFF method is a typical approach for this purpose. However, the drawbacks of long iteration time and poor ability to express curved surfaces make the industry not shown their due interest so far in the ON/OFF method. The purpose of this paper is to study a novel ON/OFF method for topology optimization, which can bring feasible optimized shapes that are more friendly for industrial realization in a shorter time.\u0000\u0000\u0000Design/methodology/approach\u0000The proposed improved ON/OFF method uses structured triangular elements for finite element modeling because the triangular elements can more freely express shape features. Every four triangular elements are pieced together to form a square cell, each quadrilateral cell is associated with a binary value indicating the material state of the four triangular elements. The binary metaheuristic algorithms are used to optimize the material distribution. After the material filling for the elements based on the output of the metaheuristic algorithm, a two-step surface smoother will be performed as the postprocess to make the shapes more friendly for manufacturing.\u0000\u0000\u0000Findings\u0000The comparative numerical results on a benchmark topology optimization problem show that the proposed method can bring feasible optimized shapes that are more friendly for industrial realization in a shorter time. In addition, the speed and robustness of convergence, especially in the case of multiobjective topology optimization problem, are significantly improved.\u0000\u0000\u0000Originality/value\u0000A novel ON/OFF method for topology optimization is proposed. Compared with the traditional ON/OFF method, the proposed method is better in terms of searching efficiency and robustness. Moreover, the proposed method can provide feasible optimized shapes that are more friendly for industrial realization.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"15 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74899072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Normal force calculation of two-degree-of-freedom direct drive induction motor considering coupling effect","authors":"R. Nie, Yaqian Meng, Peixin Wang, P. Su, J. Si","doi":"10.1108/compel-11-2022-0404","DOIUrl":"https://doi.org/10.1108/compel-11-2022-0404","url":null,"abstract":"\u0000Purpose\u0000The purpose of this study is to calculate the normal force of a two degree of freedom direct drive induction motor considering coupling effects based on an analytical model. Compared with the traditional single degree of freedom motor, normal force characteristics of two-degree-of-freedom direct drive induction motor (2DOFDDIM) is affected by coupling effect when the machine is in a helical motion. To theoretically explain the influence mechanism of coupling effect, this paper conducts a quantitative analysis of the influence of coupling effect on normal force based on the established analytical model of normal force considering coupling effect.\u0000\u0000\u0000Design/methodology/approach\u0000Firstly, the normal forces generated by 2DOFDDIM in linear motion, rotary motion and helical motion are investigated and compared to prove the effect of the coupling effect on the normal force. During this study, several coupling factors are established to modify the calculation equations of the normal force. Then, based on the multilayer theoretical method and Maxwell stress method, a novel normal force calculation model of 2DOFDDIM is established taking the coupling effect into account, which can easily calculate the normal force of 2DOFDDIM under different motions conditions. Finally, the calculation results are verified by the results of 3D finite element model, which proves the correctness of the established calculating model.\u0000\u0000\u0000Findings\u0000The coupling effect produced by the helical motion of 2DOFDDIM affects the normal force.\u0000\u0000\u0000Originality/value\u0000In this paper, the analytical model of the normal force of 2DOFDDIM considering the coupling effect is established, which provides a fast calculation for the design of the motor.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"461 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82978925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Target classification using radar cross-section statistics of millimeter-wave scattering","authors":"A. Coşkun, S. Bilicz","doi":"10.1108/compel-12-2022-0446","DOIUrl":"https://doi.org/10.1108/compel-12-2022-0446","url":null,"abstract":"\u0000Purpose\u0000This paper aims to discuss the classification of targets based on their radar cross-section (RCS). The wavelength, the dimensions of the targets and the distance from the antenna are in the order of 1 mm, 1 m and 10 m, respectively.\u0000\u0000\u0000Design/methodology/approach\u0000The near-field RCS is considered, and the physical optics approximation is used for its numerical calculation. To model real scenarios, the authors assume that the incident angle is a random variable within a narrow interval, and repeated observations of the RCS are made for its random realizations. Then, the histogram of the RCS is calculated from the samples. The authors use a nearest neighbor rule to classify conducting plates with different shapes based on their RCS histogram.\u0000\u0000\u0000Findings\u0000This setup is considered as a simple model of traffic road sign classification by millimeter-wavelength radar. The performance and limitations of the algorithm are demonstrated through a set of representative numerical examples.\u0000\u0000\u0000Originality/value\u0000The proposed method extends the existing tools by using near-field RCS histograms as target features to achieve a classification algorithm.\u0000","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"19 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82018612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improved Adaptive Feedback Control for a High-Power-Density Transformer-Less Online UPS","authors":"Maida Farooq, K. Afridi","doi":"10.1109/COMPEL52896.2023.10221012","DOIUrl":"https://doi.org/10.1109/COMPEL52896.2023.10221012","url":null,"abstract":"This paper presents an improved adaptive feedback control strategy for the inversion stage of the recently proposed high-power-density transformer-less single-phase online uninterruptible power supply (UPS). The proposed inversion stage operates in buck/buck-boost mode depending on the sinusoidal output voltage polarity. This dual-mode operation of the inversion stage under standard feedback control leads to inadequate output voltage regulation, resulting in a significant increase in total harmonic distortion (THD) of the output voltage. While the previously proposed adaptive feedback control strategy offers some improvement in output voltage total harmonic distortion (THD) compared to standard feedback control, the reduction achieved is limited. This limitation renders the THD reduction inadequate and unsuitable for practical applications. To achieve substantially better output voltage regulation and hence lower the output voltage THD, an improved adaptive feedback control strategy is proposed. To facilitate the design of the associated controllers and enable a performance comparison, analytical models that capture the dynamics of the inversion stage with both adaptive feedback and improved adaptive feedback control strategies are provided. A GaN-based 1-kW prototype high-power-density online UPS is designed, built, and tested to validate the effectiveness of the adaptive feedback and the proposed improved adaptive feedback control strategies. The improved adaptive feedback control strategy results in a 50% reduction in the output voltage THD compared to the previously proposed adaptive feedback control strategy across a wide output power range.","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"4 1","pages":"1-6"},"PeriodicalIF":0.7,"publicationDate":"2023-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73630402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-k Dielectric Assisted Trench Termination of the 4H-SiC Super Junction Device for Improved Avalanche Capability","authors":"Qi Zhu","doi":"10.1109/COMPEL52896.2023.10221057","DOIUrl":"https://doi.org/10.1109/COMPEL52896.2023.10221057","url":null,"abstract":"The conventional trench termination for the 4HSiC sidewall-implanted Super Junction device has relatively low avalanche capability and the devices can fail destructively under abnormal operating conditions. In this paper, a novel high-k dielectric assisted trench termination is proposed. The high-k dielectric TiO2 is incorporated into the SiO2-filled trench. TCAD simulations are conducted to validate the efficacy of the proposed termination. The results show that with the proposed termination, the peak electric field is pushed to the edge of the TiO2 region, preventing breakdown at the corners of the active region edge; at the same time, the leakage current flows uniformly from the active region, thus improving the avalanche current; in addition, the addition of TiO2 to the terminator does not reduce the breakdown voltage. Moreover, the dimensions of the TiO2 are optimized in terms of the maximum current density. By taking the dielectric strength into consideration, the optimum depth and length of the TiO2 region are found to be 0.6μm and 2μm, respectively.","PeriodicalId":55233,"journal":{"name":"Compel-The International Journal for Computation and Mathematics in Electrical and Electronic Engineering","volume":"38 1","pages":"1-6"},"PeriodicalIF":0.7,"publicationDate":"2023-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76874029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}