scholarly journals Impact Analysis of Transmission Congestion on Power System Flexibility in Korea

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2191 ◽  
Author(s):  
Changgi Min
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Impact Analysis ◽  
Renewable Energy Resources ◽  
Transmission Congestion ◽  
The North ◽  
Net Load ◽  
The Impact ◽  
Power System Flexibility

This study proposes a method to evaluate the impact of transmission congestion on the flexibility of a power system, based on the ramping capability shortage expectation (RSE). Here, flexibility refers to the ability to retain a power balance in response to changes in the net load. The flexibility issue arises due to the extensive integration of renewable energy resources; specifically, the higher the degree of integration, and the greater the variability and uncertainty in the power system. Flexibility is further limited by the net transfer capacity (NTC) of transmission lines. Here, we propose a method capable of capturing the extent to which transmission congestion affects the power system, to identify transmission reinforcement options for improved flexibility. In Korea, transmission congestion occurs frequently in regions to the north and southeast. A case study for a Korean power system in 2030 was conducted. Simulation results showed that the impact of transmission reinforcement in flexibility tends to be proportional to the NTC and is greater when the penetration level is low.

scholarly journals Impact Analysis of 220 Kv And 400 Kv Transmission Lines on The Integrated Nepal Power System

2020 ◽  
Vol 2 (1) ◽  
pp. 75-80
Author(s):  
Ganesh Bhandari ◽  
Bishal Rimal ◽  
Sandeep Neupane
Keyword(s):  
Power System ◽  
Transmission Line ◽  
Transmission Lines ◽  
Impact Analysis ◽  
Flow Analysis ◽  
Load Flow ◽  
Active Power ◽  
Total System ◽  
Voltage Profile ◽  
The Impact

 Power is an essential requirement for the economic development of any country. To maintain the generation of electric power at an adequate level the power has to be transmitted in a proper form to the consumer. For determination of line losses, voltage profiles and expansion of system, load flow analysis is most essential tools. This paper deals with the impact analysis of new 220 kV and 400 kV lines on Interconnected Nepal Power System (132 kV grid) in Electrical Transient Analyzer Program (ETAP). It represents the present scenario of the power system of Nepal and their impact analysis. Load flow result of existing 132 kV line shows that there is about 44.56 MW active power losses in the transmission line before any compensation techniques. After the Optimal Capacitor Placement, in the existing transmission line the active power loss decreases to about 34.224 MW as well as the voltage profile at each bus improves. The load flow result of the under construction 220 kV and 400 kV lines on the existing line shows that the total system loss would decrease to about 27.445 MW with the voltage profile improvement. The simulated model, result and analysis are presented in this paper.

scholarly journals Analyzing the Impact of Variability and Uncertainty on Power System Flexibility

2019 ◽  
Vol 9 (3) ◽  
pp. 561 ◽  
Author(s):  
Chang-Gi Min
Keyword(s):  
Sensitivity Analysis ◽  
Renewable Energy ◽  
Power System ◽  
Energy Resources ◽  
Renewable Energy Resources ◽  
Specific System ◽  
Efficient Operation ◽  
The Impact ◽  
Power System Flexibility ◽  
Flexibility Index

This study investigates the impact of variability and uncertainty on the flexibility of a power system. The variability and uncertainty make it harder to maintain the balance between load and generation. However, most existing studies on flexibility evaluation have not distinguished between the effects of variability and uncertainty. The countermeasures to address variability and uncertainty differ; thus, applying strategies individually tailored to variability and uncertainty is helpful for more efficient operation and planning of a power system. The first contribution of this study is in separating the variability and uncertainty, and determining which is more influential in terms of flexibility in specific system situations. A flexibility index, named the ramping capability shortage probability (RSP), is used to quantify the extent to which the variability and uncertainty affect the flexibility. The second contribution is to generate various scenarios for variability and uncertainty based on a modified IEEE-RTS-96, to evaluate the flexibility. The penetration level of renewable energy resources is kept the same in each scenario. The results of a sensitivity analysis show that variability is more effective than uncertainty for high and medium net loads.

scholarly journals Investigating the Effect of Uncertainty Characteristics of Renewable Energy Resources on Power System Flexibility

2021 ◽  
Vol 11 (12) ◽  
pp. 5381
Author(s):  
Changgi Min
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Forecast Error ◽  
Energy Resources ◽  
Renewable Energy Resources ◽  
Load Forecast ◽  
Simulation Results ◽  
Net Load ◽  
Power System Flexibility ◽  
Skewness And Kurtosis

This study investigates the effect of uncertainty characteristics of renewable energy resources on the flexibility of a power system. The more renewable energy resources introduced, the greater the imbalance between load and generation. Securing the flexibility of the system is becoming important to manage this situation. The degree of flexibility cannot be independent of the uncertainty of the power system. However, most existing studies on flexibility have not explicitly considered the effects of uncertainty characteristics. Therefore, this study proposes a method to quantitatively analyze the effect of uncertainty characteristics on power system flexibility. Here, the uncertainties of the power system indicate the net load forecast error, which can be represented as a probability distribution. Of the characteristics of the net load forecast error, skewness and kurtosis were considered. The net load forecast error was modeled with a Pearson distribution, which has been widely used to generate the probability density function with skewness and kurtosis. Scenarios for the forecast net load, skewness, and kurtosis were generated, and their effects on flexibility were evaluated. The simulation results for the scenarios based on a modified IEEE-RTS-96 revealed that skewness is more effective than kurtosis. The proposed method can help system operators to efficiently respond to changes in the uncertainty characteristics of renewable energy resources.

A general practice provider federation in a mixed health economy in England: a case study investigation

2018 ◽  
Vol 68 (suppl 1) ◽  
pp. bjgp18X696929
Author(s):  
Jill Mitchell
Keyword(s):  
General Practice ◽  
Shared Vision ◽  
Health Economy ◽  
Structured Interviews ◽  
The North ◽  
Common Strategy ◽  
Common Purpose ◽  
Collaborative Working ◽  
The Impact

BackgroundThere is an emerging debate that general practice in its current format is out-dated and there is a requirement to move to a federated model of provision where groups of Practices come together. The emergence of federations has developed over the past 5 years but the factors that influence how federations develop and the impact of this new model is an under researched area.AimThe study explored the rationale around why a group of independent GP practices opted to pursue an alternative business venture and the benefits that this strategy offered.MethodA single organisational case study of a federation in the North of England was conducted between 2011–2016. Mixed methods data collection included individual and group semi-structured interviews and quantitative surveys.ResultsFederations promote collaborative working, relying on strategic coherence of multiple individual GP practices through a shared vision and common purpose. Findings revealed many complexities in implementing a common strategy across multiple independent businesses. The ability of the federation to gain legitimacy was two dimensional – externally and internally. The venture had mixed successes, but their approach to quality improvement proved innovative and demonstrated outcomes on a population basis. The study identified significant pressures that practices were experiencing and the need to seek alternative ways of working but there was no shared vision or inclination to relinquish individual practice autonomy.ConclusionOrganisational development support is critical to reform General Practice. Whether central funding through the GP Five Year Forward View will achieve the scale of change required is yet to be evidenced.

Ten Demi-Culverins for Aldeburgh: Whitehall, the Dunkirkers, and a Suffolk Fishing Community, 1625–1630

2019 ◽  
Vol 58 (2) ◽  
pp. 315-337 ◽  
Author(s):  
Thomas Cogswell
Keyword(s):  
North Sea ◽  
East Coast ◽  
Central Government ◽  
Fishing Community ◽  
Close Attention ◽  
The North ◽  
The North Sea ◽  
The Impact

AbstractHistorians have not paid close attention to the activities of freebooters operating out of Dunkirk in the late 1620s. This essay corrects that omission by first studying the threat from Dunkirk to England's east coast and then addressing how the central government, counties, and coastal towns responded. A surprisingly rich vein of manuscript material from Great Yarmouth and particularly from the Suffolk fishing community of Aldeburgh informs this case study of the impact of this conflict around the North Sea.

scholarly journals Evaluating the efficacy of technical measures: a case study of selection device legislation in the UK Crangon crangon (brown shrimp) fishery

2008 ◽  
Vol 65 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Tom L. Catchpole ◽  
Andrew S. Revill ◽  
James Innes ◽  
Sean Pascoe
Keyword(s):  
Brown Shrimp ◽  
Crangon Crangon ◽  
Shrimp Fishery ◽  
The North ◽  
Ex Post ◽  
Wide Range ◽  
The Uk ◽  
The Impact ◽  
Technical Measures

Abstract Catchpole, T. L., Revill, A. S., Innes, J., and Pascoe, S. 2008. Evaluating the efficacy of technical measures: a case study of selection device legislation in the UK Crangon crangon (brown shrimp) fishery. – ICES Journal of Marine Science, 65: 267–275. Bycatch reduction devices are being introduced into a wide range of fisheries, with shrimp and prawn fisheries particularly targeted owing to the heavy discarding common in these fisheries. Although studies are often undertaken to estimate the impact of a technical measure on the fishery before implementation, rarely have the impacts been assessed ex post. Here, the efficacy of the UK legislation pertaining to the use of sievenets in the North Sea Crangon crangon fishery is assessed. Three impacts were evaluated: on fisher behaviour (social), on the level of bycatch (biological), and on vessel profitability (economic). An apparent high level of compliance by skippers was identified despite a low level of enforcement. The estimated reduction in fleet productivity following the introduction of the legislation was 14%, equalling the mean loss of Crangon landings when using sievenets calculated from catch comparison trawls. Sievenets did reduce the unnecessary capture of unwanted marine organisms, but were least effective at reducing 0-group plaice, which make up the largest component of the bycatch. Clearly the legislation has had an effect in the desired direction, but it does not address sufficiently the bycatch issue in the Crangon fishery.

scholarly journals Evacuation Data from a Hospital Outpatient Drill The Case Study of North Shore Hospital

2020 ◽  
Vol 5 ◽  
Author(s):  
Anass Rahouti ◽  
Ruggiero Lovreglio ◽  
Phil Jackson ◽  
Sélim Datoussaïd
Keyword(s):  
Built Environment ◽  
Fire Safety ◽  
Movement Time ◽  
Data Set ◽  
Healthcare Facilities ◽  
Staff Members ◽  
North Shore ◽  
The North ◽  
The Impact

Assessing the fire safety of buildings is fundamental to reduce the impact of this threat on their occupants. Such an assessment can be done by combining existing models and existing knowledge on how occupants behave during fires. Although many studies have been carried out for several types of built environment, only few of those investigate healthcare facilities and hospitals. In this study, we present a new behavioural data-set for hospital evacuations. The data was collected from the North Shore Hospital in Auckland (NZ) during an unannounced drill carried out in May 2017. This drill was recorded using CCTV and those videos are analysed to generate new evacuation model inputs for hospital scenarios. We collected pre-movement times, exit choices and total evacuation times for each evacuee. Moreover, we estimated pre-movement time distributions for both staff members and patients. Finally, we qualitatively investigated the evacuee actions of patients and staff members to study their interaction during the drill. The results show that participants were often independent from staff actions with a majority able to make their own decision.

MoDSEL

2012 ◽  
pp. 572-594
Author(s):  
Ersin Er ◽  
Bedir Tekinerdogan
Keyword(s):  
Software Development ◽  
Impact Analysis ◽  
Software Evolution ◽  
Academic Research ◽  
Model Driven ◽  
Model Driven Software Development ◽  
Basic Concepts ◽  
The Impact ◽  
Development And Evolution

Model-Driven Software Development (MDSD) aims to support the development and evolution of software intensive systems using the basic concepts of model, metamodel, and model transformation. In parallel with the ongoing academic research, MDSD is more and more applied in industrial practices. Like conventional non-MDSD practices, MDSD systems are also subject to changing requirements and have to cope with evolution. In this chapter, the authors provide a scenario-based approach for documenting and analyzing the impact of changes that apply to model-driven development systems. To model the composition and evolution of an MDSD system, they developed the so-called Model-Driven Software Evolution Language (MoDSEL) which is based on a megamodel for MDSD. MoDSEL includes explicit language abstractions to specify both the model elements of an MDSD system and the evolution scenarios that might apply to model elements. Based on MoDSEL specifications, an impact analysis is performed to assess the impact of evolution scenarios and the sensitivity of model elements. A case study is provided to show different kind of evolution scenarios and the required adaptations to model elements.

scholarly journals Transient Impact Analysis of High Renewable Energy Sources Penetration According to the Future Korean Power Grid Scenario

2018 ◽  
Vol 10 (11) ◽  
pp. 4140 ◽  
Author(s):  
Seungchan Oh ◽  
Heewon Shin ◽  
Hwanhee Cho ◽  
Byongjun Lee
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Electric Power ◽  
Power Plants ◽  
Transient Stability ◽  
Impact Analysis ◽  
Renewable Energy Sources ◽  
Electric Power System ◽  
Energy Sources ◽  
The Impact

Efforts to reduce greenhouse gas emissions constitute a worldwide trend. According to this trend, there are many plans in place for the replacement of conventional electric power plants operating using fossil fuels with renewable energy sources (RESs). Owing to current needs to expand the RES penetration in accordance to a new National power system plan, the importance of RESs is increasing. The RES penetration imposes various impacts on the power system, including transient stability. Furthermore, the fact that they are distributed at multiple locations in the power system is also a factor which makes the transient impact analysis of RESs difficult. In this study, the transient impacts attributed to the penetration of RESs are analyzed and compared with the conventional Korean electric power system. To confirm the impact of the penetration of RESs on transient stability, the effect was analyzed based on a single machine equivalent (SIME) configuration. Simulations were conducted in accordance to the Korean power system by considering the anticipated RES penetration in 2030. The impact of RES on transient stability was provided by a change in CCT by increasing of the RES penetration.

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