scholarly journals Future Directions for Electric Propulsion Research

Aerospace ◽  
2020 ◽  
Vol 7 (9) ◽  
pp. 120 ◽  
Author(s):  
Ethan Dale ◽  
Benjamin Jorns ◽  
Alec Gallimore
Keyword(s):  
Power Systems ◽  
Electric Propulsion ◽  
Large Scale ◽  
Data Driven ◽  
Hall Thrusters ◽  
Future Directions ◽  
Ion Thrusters ◽  
Open Questions ◽  
S Curve ◽  
Near Future

The research challenges for electric propulsion technologies are examined in the context of s-curve development cycles. It is shown that the need for research is driven both by the application as well as relative maturity of the technology. For flight qualified systems such as moderately-powered Hall thrusters and gridded ion thrusters, there are open questions related to testing fidelity and predictive modeling. For less developed technologies like large-scale electrospray arrays and pulsed inductive thrusters, the challenges include scalability and realizing theoretical performance. Strategies are discussed to address the challenges of both mature and developed technologies. With the aid of targeted numerical and experimental facility effects studies, the application of data-driven analyses, and the development of advanced power systems, many of these hurdles can be overcome in the near future.

scholarly journals An Improved Constrained Order Optimization Algorithm for Uncertain SCUC Problem Solving

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4498 ◽  
Author(s):  
Junjie Jia ◽  
Nan Yang ◽  
Chao Xing ◽  
Haoze Chen ◽  
Songkai Liu ◽  
...  
Keyword(s):  
Power Systems ◽  
Large Scale ◽  
Unit Commitment ◽  
Test System ◽  
Data Driven ◽  
Discrete Variable ◽  
Rough Model ◽  
Power Dispatching ◽  
Security Constraint ◽  
Identification Strategy

Studying the faster and more efficient method of solving the uncertain security-constrained unit commitment (SCUC) problem is an urgent need for the development of power systems under the background of large-scale wind power access and power dispatching. This study proposes an improved constrained order optimization (COO) algorithm to solve the uncertain SCUC problem. First, the data-driven discrete variable identification strategy is incorporated into the COO rough model, and then, the invalid security constraints identification strategy is incorporated into the COO accurate model. Finally, the improved COO algorithm combines the discrete variable identification with the invalid security constraint identification to make the uncertain SCUC decision. The results of the IEEE 118-bus test system showed that, compared with the traditional COO algorithm, the improved COO algorithm proposed has higher accuracy and better efficiency.

scholarly journals Realizing the Clinical Potential of Computational Psychiatry: Report from the Banbury Center Meeting, February 2019

2019 ◽  
Author(s):  
Michael Browning ◽  
Cameron Carter ◽  
Christopher Hughes Chatham ◽  
Hanneke den Ouden ◽  
Claire Gillan ◽  
...  
Keyword(s):  
Large Scale ◽  
Cold Spring Harbor ◽  
Data Driven ◽  
Measurement Properties ◽  
Computational Psychiatry ◽  
Cold Spring ◽  
Study Designs ◽  
Clinical Potential ◽  
Near Future ◽  
Clinical Problems

In February 2019 a workshop was convened at the Banbury Centre at Cold Spring Harbor, NY. The purpose of the meeting was to identify key developments required in the practice and infrastructure of computational psychiatry research to accelerate its ability to address real world clinical problems in the near future. This report provides a summary of the conclusions of the meeting. At its core are suggestions to improve the measurement properties of computational assays through a rapid, iterative process that leverages coordinated waves of online and clinical testing, followed by deployment of the assays in innovative study designs to address clinically relevant questions. We particularly focus on theory-driven tasks but, where possible, the potential of data-driven approaches is also highlighted. Finally, the report suggests that for the promise of computational psychiatry to be realized, the research environment must be developed to encourage large-scale, collaborative, interdisciplinary consortia.

Cost- und Monitoring-Projekt: Zwei neue forstliche Meinungsumfragen im Vergleich | The Cost- and Monitoring-Projects: A Comparison of Two New Forestry Opinion Polls

2000 ◽  
Vol 151 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Stephan Wild-Eck ◽  
Willi Zimmermann
Keyword(s):  
Large Scale ◽  
Forest Policy ◽  
Forest Economics ◽  
Positive Attitudes ◽  
Federal Institute ◽  
Swiss Confederation ◽  
Institute Of Technology ◽  
The Cost ◽  
Near Future ◽  
Opinion Polls

Two large-scale surveys looking at attitudes towards forests, forestry and forest policy in the second half ofthe nineties have been carried out. This work was done on behalf of the Swiss Confederation by the Chair of Forest Policy and Forest Economics of the Federal Institute of Technology (ETH) in Zurich. Not only did the two studies use very different methods, but the results also varied greatly as far as infrastructure and basic conditions were concerned. One of the main differences between the two studies was the fact that the first dealt only with mountainous areas, whereas the second was carried out on the whole Swiss population. The results of the studies reflect these differences:each produced its own specific findings. Where the same (or similar) questions were asked, the answers highlight not only how the attitudes of those questioned differ, but also views that they hold in common. Both surveys showed positive attitudes towards forests in general, as well as a deep-seated appreciation ofthe forest as a recreational area, and a positive approach to tending. Detailed results of the two surveys will be available in the near future.

Overview of Subsynchronous Oscillation in Grid-connected Wind Farm

2020 ◽  
Vol 13 (7) ◽  
pp. 969-979
Author(s):  
Xu Pei-Zhen ◽  
Lu Yong-Geng ◽  
Cao Xi-Min
Keyword(s):  
Power Systems ◽  
Wind Turbine ◽  
Large Scale ◽  
Wind Farm ◽  
Wind Farms ◽  
Induction Generator ◽  
Future Research ◽  
Stable Operation ◽  
Subsynchronous Oscillation ◽  
Different Types

Background: Over the past few years, the subsynchronous oscillation (SSO) caused by the grid-connected wind farm had a bad influence on the stable operation of the system and has now become a bottleneck factor restricting the efficient utilization of wind power. How to mitigate and suppress the phenomenon of SSO of wind farms has become the focus of power system research. Methods: This paper first analyzes the SSO of different types of wind turbines, including squirrelcage induction generator based wind turbine (SCIG-WT), permanent magnet synchronous generator- based wind turbine (PMSG-WT), and doubly-fed induction generator based wind turbine (DFIG-WT). Then, the mechanisms of different types of SSO are proposed with the aim to better understand SSO in large-scale wind integrated power systems, and the main analytical methods suitable for studying the SSO of wind farms are summarized. Results: On the basis of results, using additional damping control suppression methods to solve SSO caused by the flexible power transmission devices and the wind turbine converter is recommended. Conclusion: The current development direction of the SSO of large-scale wind farm grid-connected systems is summarized and the current challenges and recommendations for future research and development are discussed.

scholarly journals Series Compensation of Transmission Systems: A Literature Survey

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1717
Author(s):  
Camilo Andrés Ordóñez ◽  
Antonio Gómez-Expósito ◽  
José María Maza-Ortega
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Power System ◽  
Case Studies ◽  
Electronic Devices ◽  
Literature Survey ◽  
Power Electronic ◽  
Transmission Systems ◽  
Series Compensation ◽  
Near Future

This paper reviews the basics of series compensation in transmission systems through a literature survey. The benefits that this technology brings to enhance the steady state and dynamic operation of power systems are analyzed. The review outlines the evolution of the series compensation technologies, from mechanically operated switches to line- and self-commutated power electronic devices, covering control issues, different applications, practical realizations, and case studies. Finally, the paper closes with the major challenges that this technology will face in the near future to achieve a fully decarbonized power system.

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