Article
Engineering, Electrical & Electronic
Junru Chen, Rongwu Zhu, Ismail Ibrahim, Terence O'Donnell, Marco Liserre
Summary: The article proposes a closed-loop NC optimization control strategy to minimize neutral current and suppress overcurrent, aiming to enhance the flexibility and efficiency of smart transformers under unbalanced loading conditions.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Neha Beniwal, Glen Ghias Farivar, Hin Sang Lam, Salvador Ceballos, Naga Brahmendra Yadav Gorla, Josep Pou, Shu Yuen Ron Hui, Frede Blaabjerg
Summary: This article proposes a dual-layer modulation technique for controlling the average neutral-point current in NPC converters. The technique uses two modulation layers to independently synthesize the voltage reference and ANC reference, and offers faster dynamics and reduced mathematical computations compared to conventional approaches.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Wei Du, Kevin P. P. Schneider, Greg P. P. Wiegand, Francis K. K. Tuffner, Jing Xie, Orris L. L. Dent
Summary: This paper proposes a supplemental control strategy for dynamic voltage restorers (DVRs) to improve the primary frequency response of microgrids by regulating voltage-dependent loads. Experimental and simulation results show that the supplemental control can effectively improve the primary frequency response of microgrids, expanding the functionality of DVRs from power quality improvement to frequency regulation.
IEEE TRANSACTIONS ON SMART GRID
(2023)
Article
Engineering, Electrical & Electronic
Faycal Benyamina, Abdeldjabar Benrabah, Farid Khoucha, Muhammad Fahad Zia, Yahia Achour, Mohamed Benbouzid
Summary: This study proposes a fault ride-through capability control method for grid-feeding inverters, ensuring stable operation during grid faults through strategies such as dual current control and real-time active power reduction.
ELECTRIC POWER SYSTEMS RESEARCH
(2021)
Article
Engineering, Electrical & Electronic
Jilang Qiu, Yingjie He, Chao Lei, Qianming Jiao, Jinjun Liu
Summary: Transformerless three-level inverters have advantages over two-level inverters in photovoltaic systems. An improved LMSVM method is proposed to better control the neutral point and leakage current, allowing the use of high CMV small vectors and medium vector sequences. The ILMSVM method has advantages in regulating NP potential and suppressing leakage current spikes.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Shuangcheng Song, Shuai Dong, Qianfan Zhang
Summary: This study introduces a CR control scheme to address the current stress issue on the receiver side of the wireless charging system, achieving some improvement under high-speed conditions.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Automation & Control Systems
Kaimiao Wang, Bo Zhou, Xingwei Zhou, Jiadan Wei, Zhenggui Zhou
Summary: This article proposes a minimum field current increment control strategy for the conventional doubly salient electromagnetic generator (DSEG) system with uncontrolled rectification. Based on the output voltage estimation model of APC and controlling the conduction angle, the dynamic response of the system is improved.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Automation & Control Systems
Tianbao Yu, Wenchao Wan, Shanxu Duan
Summary: A novel modulation technique for NPC PV inverter is proposed in this article, which eliminates leakage current by combining ZCMV PWM and two other modulation modes, and balances NP voltage by adjusting NP current, effectively eliminating leakage current.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Biks Alebachew Taye, Nalin Behari Dev Choudhury
Summary: Equal load sharing and maintaining constant DC bus voltage are the main challenges in DC microgrids. The droop control method is effective but has conflicting goals of accurate current sharing and voltage regulation. This paper proposes a new droop control algorithm that updates the droop resistance value based on load demand to improve sharing and regulation. The effectiveness of this method is evaluated using simulation and experimental studies.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Shu Ye, Jianguo Jiang, Jiayan Jiang, Zhongzheng Zhou, Yunlong Liu, Cong Liu
Summary: The article introduces a dynamic-segment-alternating SVPWM (DSA-SVPWM) based on a five-level nested NP piloted converter, which effectively balances the NP potential and reduces harmonic distortions, showing good generalization ability.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Joseba Erdocia, Andoni Urtasun, Luis Marroyo
Summary: The rapid uptake of renewable energy sources has led to the replacement of synchronous generators with power electronic inverters, which need to exhibit traditional synchronous generator characteristics. Therefore, it has been proposed to control the inverters in a grid-forming mode to support microgrid voltage. To protect power electronics from overcurrents, this article proposes a dual voltage-current control method that enables the grid-forming inverters to quickly limit the current under any overload or short-circuit condition.
IEEE JOURNAL OF EMERGING AND SELECTED TOPICS IN POWER ELECTRONICS
(2022)
Article
Green & Sustainable Science & Technology
Jinghang Lu, Xingyu Zhang, Bingfu Zhang, Xiaochao Hou, Peng Wang
Summary: A distributed dynamic event-triggered control method is proposed in this paper to solve the problem of simultaneous DC bus voltage recovery and current sharing in islanded DC microgrids. This control scheme can ensure DC bus voltage deviation removal and achieve current sharing among distributed generation units without requiring global information. The method involves data of neighboring DGs only at event-triggered times, reducing the communication burden of the DC microgrid network. The stability of the proposed method is demonstrated using the Lyapunov function and Zeno behavior is excluded. Experimental results with four case studies validate the effectiveness of the proposed method.
IEEE TRANSACTIONS ON SUSTAINABLE ENERGY
(2022)
Article
Engineering, Electrical & Electronic
Pedro Goncalves, Sergio Cruz, Andre Mendes
Summary: This paper proposes a predictive current control strategy based on virtual vectors for six-phase permanent magnet synchronous (PMSM) drives. The method reduces current harmonic distortion, decreases copper losses, and is suitable for fault-tolerant operation.
Article
Engineering, Electrical & Electronic
Wenchao Wan, Shanxu Duan, Changsong Chen, Tianbao Yu
Summary: The article proposes a hybrid control method that combines zero-sequence voltage regulation with the decomposition of modulation waveform, effectively reducing the neutral-point voltage fluctuation in three-level inverters and validating its effectiveness in experiments conducted on a 10-kVA three-level platform.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Hongliang Zhang, Chenghui Zhang, Xiangyang Xing, Chang Liu, Xiaoyan Li, Boxue Zhang
Summary: This paper proposes a three-layer double-vector FCS-MPC method to address the challenges of current distortion elimination, current ripple mitigation, and NP voltage balance in the Vienna rectifier. By dividing the sectors and selecting candidate vectors to reduce current distortion, adopting double vectors with optimal duty cycles to reduce current ripples, and balancing the NP voltage by selecting redundant p-type or n-type small vectors, the proposed method achieves simultaneous current distortion elimination, current ripple mitigation, and NP voltage balancing. The effectiveness of the method has been verified through simulation and experiment.
IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION
(2022)
Article
Physics, Fluids & Plasmas
A. Lvovskiy, C. Paz-Soldan, N. W. Eidietis, A. Dal Molin, G. H. DeGrandchamp, E. M. Hollmann, J. B. Lestz, C. Liu, M. Nocente, D. Shiraki, X. D. Du
Summary: The dependencies of Alfvenic instabilities driven by runaway electrons (REs) during current quench in DIII-D on plasma and material injection parameters were investigated. The observed instabilities in the frequency range of 0.1-3 MHz are correlated with increased RE loss and may play a role in non-sustained RE beams.
Article
Physics, Fluids & Plasmas
J. Varela, K. Nagasaki, S. Kobayashi, K. Nagaoka, P. Adulsiriswad, A. Cappa, S. Yamamoto, K. Y. Watanabe, D. A. Spong, L. Garcia, Y. Ghai, J. Ortiz
Summary: The effect of electron cyclotron heating (ECH) on the stability of Alfven eigenmodes (AEs) and energetic particle modes (EPMs) triggered by energetic ions in Heliotron J plasma was analyzed in this study. The analysis used the FAR3d code to simulate a reduced MHD model for the thermal plasma coupled with a gyrofluid model for the energetic particle species. The simulations reproduced the observed stability trends of AE/EPM as electron temperature (T-e) increased, modifying various parameters.
Article
Astronomy & Astrophysics
J. Varela, F. Pantellini
Summary: The aim of this study was to identify the solar wind conditions required for the formation of slow-mode structures (SMS) in the Mercury magnetosphere by comparing MESSENGER magnetometer data and magnetohydrodynamics simulations. The results showed that optimal wind conditions for SMS formation require that the interplanetary magnetic field is oriented in the northward or radial directions. MESSENGER magnetometer data provided indirect evidence of SMS by showing a significant decrease in the magnetic field module after the satellite crossed nearby the observed compression front in the simulation.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Nuclear Science & Technology
D. B. Weisberg, J. Leuer, J. McClenaghan, J. H. Yu, W. Wehner, K. McLaughlin, T. Abrams, J. Barr, B. Grierson, B. Lyons, J. R. MacDonald, O. Meneghini, C. C. Petty, R. I. Pinsker, G. Sinclair, W. M. Solomon, T. Taylor, K. Thackston, D. Thomas, B. van Compernolle, M. VanZeeland, K. Zeller
Summary: A high-level design study for a new experimental tokamak called EXCITE shows that advances in fusion science and engineering can be leveraged to narrow the gaps in energy confinement and exhaust power handling between present devices and a future fusion pilot plant. The optimized design of a B-T=6 T, I-P=5 MA, R-0=1.5 m, A=3, D-D tokamak with advanced scenarios and high-temperature superconductor magnets matches several absolute FPP parameters and closes the gap in key dimensionless parameters. Integrated neutron shielding ensures personnel access and maximizes experimental run time.
FUSION SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
F. Turco, T. Petrie, T. Osborne, C. C. Petty, T. C. Luce, B. Grierson, T. Odstrcil, M. A. Van Zeeland, D. Liu, L. Casali, W. Boyes, S. P. Smith, H. Shen, M. Kostuk, D. Brennan
Summary: The feasibility of a radiating mantle solution was studied by injecting high-density and divertor impurities in the steady-state hybrid scenario in DIII-D experiments. The confinement of the high-density plasma was improved by increasing the density and reducing the pressure through improved confinement inside the EC deposition. The edge pressure could continue to increase without encountering a limit by injecting Ne and Ar into the divertor, but this triggered core tearing modes.
Article
Physics, Fluids & Plasmas
X. D. Du, W. W. Heidbrink, M. A. Van Zeeland, J. Gonzalez-Martin, M. E. Austin, Z. Yan, G. R. McKee
Summary: Transport of fast ions in plasma is studied at different regimes below, near, and above the Alfvén eigenmode stability threshold. Below the threshold, fast ions are well-confined without noticeable transport. Near the threshold, fast ions exhibit transport through AE-driven flow along streamlines. Above the threshold, fast ions show strong critical gradient behavior with prompt transport along streamlines.
Article
Physics, Fluids & Plasmas
H. Q. Wang, R. Hong, X. Jian, T. L. Rhodes, H. Y. Guo, A. W. Leonard, X. Ma, J. G. Watkins, J. Ren, B. A. Grierson, M. W. Shafer, F. Scotti, T. H. Osborne, D. M. Thomas, Z. Yan
Summary: The integration of a high-performance core and a dissipative divertor, or "core-edge integration," is seen as a critical issue in designing future fusion reactors. This letter presents the first experimental evidence of electron turbulence at the DIII-D H-mode pedestal, which correlates with pedestal broadening and facilitates core-edge integration. The turbulence is enhanced by high η_e (η_e = L_n / L_T_e) due to a strong shift between density and temperature profiles associated with a closed divertor. This wide pedestal, coupled with a closed divertor, provides a solution to the core-edge integration issue in future fusion reactors.
Article
Physics, Fluids & Plasmas
J. Ortiz, J. Varela, D. A. Spong, L. Garcia, Y. Ghai
Summary: The aim of this study is to analyze the linear stability of Alfven eigenmodes (AE) in the QPS device heated by a tangential neutral beam injector (NBI). The analysis is performed for different operational regimes of the NBI, including EP beta, EP energy, and radial location of the beam. The stability of AE is improved in simulations with finite beta equilibria and three period configurations.
Article
Parasitology
Hong-Yu Song, Jia-Fei Zhan, Rui-Qi Hua, Xue He, Xiao-Di Du, Jing Xu, Ran He, Yue Xie, Xiao-Bin Gu, Xue-Rong Peng, Guang-You Yang
Summary: In this study, EgADK1 and EgADK8 were cloned and expressed, and their roles in the growth and development of E. granulosus were investigated. However, they are not suitable as candidate antigens for the diagnosis of cystic echinococcosis (CE) due to their recognition by other parasite-positive sera.
PARASITOLOGY RESEARCH
(2023)
Article
Physics, Fluids & Plasmas
T. Kobayashi, Z. Yan, G. R. McKee, M. E. Austin, B. A. Grierson, P. Gohil
Summary: This paper elaborates on the unresolved issue of the prompt core confinement improvement observed at the L-H transition in DIII-D, which can have implications for future fusion reactor performance. The role of profile stiffness in understanding the mechanism of this improvement is emphasized through dynamic transport analysis, while beam emission spectroscopy reveals that ion scale turbulence density fluctuation suppression alone cannot explain the transport reduction at the core. Experimental assessments of nonlocal confinement improvement across the L-H transition are conducted in hydrogen (H) and deuterium (D) plasmas, with findings indicating a more rapid prompt core confinement improvement in the lighter hydrogen isotope.
PHYSICS OF PLASMAS
(2023)
Article
Physics, Fluids & Plasmas
J. Yang, M. Podesta, E. D. Fredrickson, C. Liu, J. W. Berkery, F. M. Poli
Summary: This study utilizes the TRANSP NTM model to investigate the role of fast ions in NSTX spontaneous NTMs. The analysis shows that fast ions play a decisive role in the early growth phase of spontaneous NTM when the passing fast ion driven kinetic neoclassical polarization current term is larger than 1% of the bootstrap current term in the modified Rutherford equation. This result is applicable to any tokamak plasmas with a fast ion drift orbit width or fast ion poloidal Larmor radius comparable to the magnetic island width.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Physics, Fluids & Plasmas
C. Holland, E. M. Bass, D. M. Orlov, J. Mcclenaghan, B. C. Lyons, B. A. Grierson, X. Jian, N. T. Howard, P. Rodriguez-Fernandez
Summary: The OMFIT STEP workflow was used to develop core plasma scenario use cases for a compact tokamak reactor. The study presents an extensive characterization of core transport and confinement, highlighting the extreme sensitivity of the results to different transport models and critical gradients. The research also proposes a simple heuristic model for transport in reactor-relevant plasmas.
JOURNAL OF PLASMA PHYSICS
(2023)
Article
Astronomy & Astrophysics
J. Varela, A. S. Brun, A. Strugarek, V Reville, P. Zarka, F. Pantellini
Summary: This study analyzes the Earth's habitability, taking into account the direct impact of the solar wind on the Earth's atmosphere. It finds that the solar wind can significantly affect the habitability of the Earth.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Physics, Fluids & Plasmas
J. Varela, D. A. Spong, L. Garcia, Y. Ghai, D. Zarzoso, D. del-Castillo-Negrete, H. Betar, J. Ortiz, D. C. Pace, M. A. Van Zeeland, X. Du, R. Sanchez, V Tribaldos, J. M. Reynolds-Barredo
Summary: This study analyzes the effect of the neutral beam injector (NBI) operation regime on the saturation phase of the Alfven Eigenmodes (AEs) in DIII-D plasma. The analysis suggests a transition from the soft MHD to the hard MHD limit if the simulation EP beta > 0.02, leading to bursting MHD activity caused by radial AEs overlapping. Simulations in the hard MHD regime show a decrease of the AE frequency in the saturation phase.
PLASMA PHYSICS AND CONTROLLED FUSION
(2023)
Article
Astronomy & Astrophysics
Ruchi Mishra, Miljenko Cemeljic, Jacobo Varela, Maurizio Falanga
Summary: The first extrasolar planets were accidentally discovered by detecting slight variations in the pulsar timing. Based on this, auroras on planets around millisecond pulsars are predicted. The radio emission from such planetary auroras could be observed using current instruments. In addition to studying extreme atmospheric conditions, the detection also provides an opportunity to probe the pulsar wind directly.
ASTROPHYSICAL JOURNAL LETTERS
(2023)