| 1. |
- Li, X., et al.
(författare)
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Adaptive Resilient Secondary Control for Microgrids With Communication Faults
- 2021
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Ingår i: IEEE Transactions on Cybernetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-2267 .- 2168-2275. ; , s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- In this article, we consider the resilience problem in the presence of communication faults encountered in distributed secondary voltage and frequency control of an islanded alternating current microgrid. Such faults include the partial failure of communication links and some classes of data manipulation attacks. This practical and important yet challenging issue has been taken into limited consideration by existing approaches, which commonly assume that the measurement or communication between the distributed generations (DGs) is ideal or satisfies some restrictive assumptions. To achieve communication resilience, a novel adaptive observer is first proposed for each individual DG to estimate the desired reference voltage and frequency under unknown communication faults. Then, to guarantee the stability of the closed-loop system, voltage and frequency restoration, and accurate power sharing regardless of unknown communication faults, sufficient conditions are derived. Some simulation results are presented to verify the effectiveness of the proposed secondary control approach.
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| 2. |
- Li, Xiaolei, et al.
(författare)
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Resilience for Communication Faults in Reactive Power Sharing of Microgrids
- 2021
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Ingår i: IEEE Transactions on Smart Grid. - : Institute of Electrical and Electronics Engineers (IEEE). - 1949-3053 .- 1949-3061. ; 12:4, s. 2788-2799
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we consider the distributed reactive power sharing control problem for an autonomous inverter-based microgrid with resilience for communication faults, which may be caused by partial communication link failures or some channel manipulation attacks. Under the standard decoupling approximation for bus angle differences, the reactive power flow of each inverter can be controlled by manipulating the voltage amplitudes of itself and its neighbour inverters. By designing an adaptive resilient cooperative control scheme, accurate reactive power sharing can be guaranteed even in the presence of communication faults. Some simulation results are presented to verify the superiority of the proposed control approach compared with the existing methods.
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| 3. |
- Wang, Baicun, et al.
(författare)
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Human Digital Twin in the context of Industry 5.0
- 2024
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Ingår i: Robotics and Computer-Integrated Manufacturing. - : Elsevier Ltd. - 0736-5845 .- 1879-2537. ; 85
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Forskningsöversikt (refereegranskat)abstract
- Human-centricity, a core value of Industry 5.0, places humans in the center of production. It leads to the prioritization of human needs, spanning from health and safety to self-actualization and personal growth. The concept of the Human Digital Twin (HDT) is proposed as a critical method to realize human-centricity in smart manufacturing systems towards Industry 5.0. HDTs are digital representations of humans, aiming to change the practice of human-system integration by coupling humans’ characteristics directly to the system design and its performance. In-depth analysis, critical insights, and application guidelines of HDT are essential to realize the concept of Industry 5.0 in practice and evolve the smart manufacturing paradigm in modern factories. However, the investigation on the development of HDT to evolve humans’ roles and develop humans to their full potential is limited to date. Recent studies are rarely geared towards designing a standardized framework and architecture of HDT for diverse real-world applications. Thus, this work aims to close this research gap by carrying out a comprehensive survey on HDT in the context of Industry 5.0, summarizing the ongoing evolution, and proposing a proper connotation of HDT, before discussing the conceptual framework and system architecture of HDT and analyzing enabling technologies and industrial applications. This work provides guidance on possible avenues as well as challenges for the further development of HDT and its related concepts, allowing humans to reach their potential and accommodating their diverse needs in the futuristic smart manufacturing systems shaped by Industry 5.0.
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| 4. |
- Wang, Ci, et al.
(författare)
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Twinning pathways in Fe and Fe-Cr alloys from first-principles theory
- 2021
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Ingår i: Acta Materialia. - : Elsevier BV. - 1359-6454 .- 1873-2453. ; 215
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Tidskriftsartikel (refereegranskat)abstract
- Using density-functional theory, we determine the generalized stacking fault energy (GSFE) for the {1 (1) over bar 12} < 1 (1) over bar 11 > twinning system in ferromagnetic (FM) body-centered cubic Fe and Fe-Cr alloys with molar fraction of Cr <= 0.5. We adopt both reflection and isosceles twinning pathways and reveal the magnetic ordering effects on the GSFE by contrasting the FM results to those obtained for the magnetically disordered paramagnetic (PM) state. The results show that the isosceles twin boundary configuration is energetically preferred in this binary. The loss of long-range magnetic order lowers the GSFE amplitude but increases the twin boundary migration (TBM) energy regardless of the Cr content. The twin boundary formation (TBF) energy and the TBM energy show non-linear dependences on Cr content in the FM and PM states, and the effect of Cr on these properties critically depends on the magnetic state. We discuss our results in regard to the stable twin boundary structure and deformation twinning experimentally observed in homogeneous Fe-50 wt.% Cr alloy up to temperatures slightly above the magnetic ordering temperature.
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| 5. |
- Yang, Qiyu, et al.
(författare)
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Adaptive distributed synchronization of heterogeneous multi-Agent systems over directed graphs with time-Varying edge weights
- 2021
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Ingår i: Journal of the Franklin Institute. - : Elsevier BV. - 0016-0032. ; 358:4, s. 2434-2452
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Tidskriftsartikel (refereegranskat)abstract
- Time-varying edge weights represent dynamical interactions between any two nodes in multi-agent systems (MASs). In this paper, we consider a synchronization problem for heterogeneous MASs over directed graphs with time-varying edge weights from a control-theoretic perspective. We seek for an adaptive control protocol that drives the synchronization error in the presence of time-varying edge weights to converge in terms of asymptotic stability. We propose a class of observer networks for estimating leaders and output regulation equation solvers built on directed graphs with time-varying edge weights. Finally, we use a simulation study to verify the effectiveness of the proposed protocol.
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| 6. |
- Yang, Yaochun, et al.
(författare)
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First-principles study of the Sigma 3(112) grain boundary in Fe-rich Fe-Cr alloys
- 2020
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Ingår i: Scripta Materialia. - : Elsevier BV. - 1359-6462 .- 1872-8456. ; 181, s. 140-143
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Tidskriftsartikel (refereegranskat)abstract
- We report a first-principles investigation of the Sigma 3(112) grain boundary (GB) in body-centered cubic Fe-rich Fe1-xCrx alloy as a function of chemical composition and temperature. The equilibrium amount of Cr at the GB undergoes a sharp transition from slight enrichment in low-alloyed Fe-Cr (x <= 0.06-0.08) to complete Cr saturation for 0.08 <= x <= 0.15. The GB chemistry at room-temperature and below is characterized by miscibility gaps, destabilizing a Fe-Cr interfacial solid solution towards decomposition into Fe-rich and Cr-rich clusters. The Cr-rich clusters at the GB may serve as nucleation centers for secondary phases in Fe-Cr alloys.
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| 7. |
- Yang, Yaochun, et al.
(författare)
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First-principles study of the Σ3(112) grain boundary in Fe-rich Fe-Cr alloys
- 2020
-
Ingår i: Scripta Materialia. - : Elsevier BV. - 1359-6462 .- 1872-8456. ; 181, s. 140-143
-
Tidskriftsartikel (refereegranskat)abstract
- We report a first-principles investigation of the Sigma 3(112) grain boundary (GB) in body-centered cubic Fe-rich Fe1-xCrx alloy as a function of chemical composition and temperature. The equilibrium amount of Cr at the GB undergoes a sharp transition from slight enrichment in low-alloyed Fe-Cr (x <= 0.06-0.08) to complete Cr saturation for 0.08 <= x <= 0.15. The GB chemistry at room-temperature and below is characterized by miscibility gaps, destabilizing a Fe-Cr interfacial solid solution towards decomposition into Fe-rich and Cr-rich clusters. The Cr-rich clusters at the GB may serve as nucleation centers for secondary phases in Fe-Cr alloys.
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