scholarly journals Multi-Level Cooperative Scheduling Based on Robust Optimization Considering Flexibilities and Uncertainties of ADN and MG

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7376
Author(s):  
Ziqi Zhang ◽  
Zhong Chen ◽  
Qi Zhao ◽  
Puliang Du
Keyword(s):  
Robust Optimization ◽  
Essential Role ◽  
Control Problems ◽  
Transmission Grid ◽  
Active Distribution Network ◽  
Flexible Resources ◽  
Level Model ◽  
Multi Level ◽  
Micro Grid ◽  
Cooperative Scheduling

This paper develops the coordination structure and method for utilizing flexibilities in a Micro-Grid (MG), an Active Distribution Network (ADN) and a Transmission Grid (TG), which can play an essential role in addressing the uncertainties caused by renewable energy power generation (REPG). For cooperative dispatching, both flexibilities and uncertainties on the interface of MG–ADN and ADN–TG are portrayed in unified forms utilizing robust optimization (RO), based on the modified equipment-level model of flexible resources. The Constraint-and-Column Generation method is adopted to solve the RO control problems. Simulations on the modified IEEE case-6 and case-33 systems are carried out. The results suggest that the proposed algorithm can exploit flexible resources in both an MG and an ADN, improving the economy and promoting REPG consumption within each level (MG, ADN and TG) while reducing uncertainties and providing flexibilities for superior operators.

An Analysis on Factors of Parent Involvement in Middle School Using Multi-Level Model

2018 ◽  
Vol 18 (5) ◽  
pp. 521-540
Author(s):  
Eunyoung Kim ◽  
◽  
Soonbum Kwon ◽  
Meejung Chin ◽  
◽  
...  
Keyword(s):  
Middle School ◽  
Parent Involvement ◽  
Level Model ◽  
Multi Level

scholarly journals A Network Analysis of the Relationship among Reading, Spelling and Maths Skills

2021 ◽  
Vol 11 (5) ◽  
pp. 656
Author(s):  
Pierluigi Zoccolotti ◽  
Paola Angelelli ◽  
Chiara Valeria Marinelli ◽  
Daniele Luigi Romano
Keyword(s):  
Network Analysis ◽  
Clinical Analysis ◽  
Skill Learning ◽  
Fifth Grade ◽  
Learning Skills ◽  
Level Model ◽  
Multi Level ◽  
Unselected Group ◽  
The Relationship

Background. Skill learning (e.g., reading, spelling and maths) has been predominantly treated separately in the neuropsychological literature. However, skills (as well as their corresponding deficits), tend to partially overlap. We recently proposed a multi-level model of learning skills (based on the distinction among competence, performance, and acquisition) as a framework to provide a unitary account of these learning skills. In the present study, we examined the performance of an unselected group of third- to fifth-grade children on standard reading, spelling, and maths tasks, and tested the relationships among these skills with a network analysis, i.e., a method particularly suited to analysing relations among different domains. Methods. We administered a battery of reading, spelling, and maths tests to 185 third-, fourth-, and fifth-grade children (103 M, 82 F). Results. The network analysis indicated that the different measures of the same ability (i.e., reading, spelling, and maths) formed separate clusters, in keeping with the idea that they are based on different competences. However, these clusters were also related to each other, so that three nodes were more central in connecting them. In keeping with the multi-level model of learning skills, two of these tests (arithmetic facts subtest and spelling words with ambiguous transcription) relied heavily on the ability to recall specific instances, a factor hypothesised to underlie the co-variation among learning skills. Conclusions. The network analysis indicated both elements of association and of partial independence among learning skills. Interestingly, the study was based on standard clinical instruments, indicating that the multi-level model of learning skills might provide a framework for the clinical analysis of these learning skills.

A Multi‐Level Model of I‐deals in Workgroups: Employee and Coworker Perceptions of Leader Fairness, I‐Deals and Group Performance

2021 ◽  
Author(s):  
Smriti Anand ◽  
Jeremy D. Meuser ◽  
Prajya R. Vidyarthi ◽  
Robert C. Liden ◽  
Denise M. Rousseau ◽  
...  
Keyword(s):  
Group Performance ◽  
Level Model ◽  
Multi Level

scholarly journals Hierarchical Scheduling Scheme for AC/DC Hybrid Active Distribution Network Based on Multi-Stakeholders

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2830 ◽  
Author(s):  
Chang Ye ◽  
Shihong Miao ◽  
Yaowang Li ◽  
Chao Li ◽  
Lixing Li
Keyword(s):  
Optimization Model ◽  
Distribution Network ◽  
Hierarchical Optimization ◽  
Active Distribution Network ◽  
Scheduling Scheme ◽  
Multi Stage ◽  
Flexible Loads ◽  
Level Model ◽  
Load Regulation ◽  
Upper Level

This paper presents a hierarchical multi-stage scheduling scheme for the AC/DC hybrid active distribution network (ADN). The load regulation center (LRC) is considered in the developed scheduling strategy, as well as the AC and DC sub-network operators. They are taken to be different stakeholders. To coordinate the interests of all stakeholders, a two-level optimization model is established. The flexible loads are dispatched by LRC in the upper-level optimization model, the objective of which is minimizing the loss of the entire distribution network. The lower-level optimization is divided into two sub-optimal models, and they are carried out to minimize the operating costs of the AC/DC sub-network operators respectively. This two-level model avoids the difficulty of solving multi-objective optimization and can clarify the role of various stakeholders in the system scheduling. To solve the model effectively, a discrete wind-driven optimization (DWDO) algorithm is proposed. Then, considering the combination of the proposed DWDO algorithm and the YALMIP toolbox, a hierarchical optimization algorithm (HOA) is developed. The HOA can obtain the overall optimization result of the system through the iterative optimization of the upper and lower levels. Finally, the simulation results verify the effectiveness of the proposed scheduling scheme.

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