scholarly journals Networks within networks: scaling response operations in the lightning complex fires in northern california, August 2020

2021 ◽  
Vol 331 ◽  
pp. 04016
Author(s):  
K. Comfort Louise
Keyword(s):  
San Francisco ◽  
Distribution Systems ◽  
Extreme Event ◽  
Electrical Power ◽  
Incident Management ◽  
Northern California ◽  
California Department ◽  
Wildfire Risk ◽  
The Impact ◽  
Large Sections

Wildfire risk has increased dramatically in California over more than two decades, 2000 - 2021, reflecting the intense impact of climate change on the state’s environmental and ecological systems. Most urgent is the impact of wildfire at the wildland-urban-interface (WUI), and the challenge to prevent cascading disaster for regions connected via interdependent lifelines of transportation, communications, electrical power, water, sewer, and gas line distribution systems that characterize geographic regions. To what extent do large, multi-organizational, multi-jurisdictional networks of organizations learn from experience and adapt their performance in response to the dynamic conditions of an actual extreme event? This article identifies four types of networks operating in the 2020 Lightning Complex Wildfires in northern California and documents the rapid escalation of risk and costs based on a preliminary analysis of the 209 incident reports filed by California Department of Forestry and Fire Protection (CalFire) for the SCU Fire that engulfed large sections of five counties in the southeastern San Francisco Bay Region. The article concludes that Interagency Incident Management Networks provide essential intelligence to support local management of operations in the dynamic context of wildfire risk.

scholarly journals Numerical and experimental investigations of the impacts of the integration of wind energy into distribution network

2021 ◽  
Author(s):  
◽  
Ramesh Kumar Behara
Keyword(s):  
Renewable Energy ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Power ◽  
Distribution Systems ◽  
Electrical Power ◽  
Distribution Network ◽  
Experimental Investigations ◽  
Doubly Fed ◽  
The Impact

The growing needs for electric power around the world has resulted in fossil fuel reserves to be consumed at a much faster rate. The use of these fossil fuels such as coal, petroleum and natural gas have led to huge consequences on the environment, prompting the need for sustainable energy that meets the ever increasing demands for electrical power. To achieve this, there has been a huge attempt into the utilisation of renewable energy sources for power generation. In this context, wind energy has been identified as a promising, and environmentally friendly renewable energy option. Wind turbine technologies have undergone tremendous improvements in recent years for the generation of electrical power. Wind turbines based on doubly fed induction generators have attracted particular attention because of their advantages such as variable speed, constant frequency operation, reduced flicker, and independent control capabilities for maximum power point tracking, active and reactive powers. For modern power systems, wind farms are now preferably connected directly to the distribution systems because of cost benefits associated with installing wind power in the lower voltage networks. The integration of wind power into the distribution network creates potential technical challenges that need to be investigated and have mitigation measures outlined. Detailed in this study are both numerical and experimental models to investigate these potential challenges. The focus of this research is the analytical and experimental investigations in the integration of electrical power from wind energy into the distribution grid. Firstly, the study undertaken in this project was to carry out an analytical investigation into the integration of wind energy in the distribution network. Firstly, the numerical simulation was implemented in the MATLAB/Simulink software. Secondly, the experimental work, was conducted at the High Voltage Direct Centre at the University of KwaZulu-Natal. The goal of this project was to simulate and conduct experiments to evaluate the level of penetration of wind energy, predict the impact on the network, and propose how these impacts can be mitigated. From the models analysis, the effects of these challenges intensify with the increased integration of wind energy into the distribution network. The control strategies concept of the doubly fed induction generator connected wind turbine was addressed to ascertain the required control over the level of wind power penetration in the distribution network. Based on the investigation outcomes we establish that the impact on the voltage and power from the wind power integration in the power distribution system has a goal to maintain quality and balance between supply and demand.

Impact of System Average Interruption Duration Index Threshold on the Reliability Assessment of Electrical Power Distribution Systems

2018 ◽  
Vol 6 (2) ◽  
pp. 17-31
Author(s):  
Ganiyu Adedayo Ajenikoko ◽  
Ridwan Abiola Oladepo
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Electrical Power ◽  
Reliability Assessment ◽  
Research Paper ◽  
Threshold Values ◽  
The Impact ◽  
Number Of Customers ◽  
System Average

System Average Interruption Duration Index (SAIDI) is one of the parametric indices used for assessment of the performance of electrical power network. It is the ratio of customers’ interruption duration to the total number of customers served. SAIDI threshold is used to determine the calendar days upon which either the system design limits or operational limits are exceeded. This research paper presents the impact of SAIDI threshold on the reliability assessment of electrical power distribution system. Data were collected from ten selected feeders of Ibadan distribution system for a period of five years. The daily SAIDI, natural logarithm of SAIDI, the log-average of SAIDI and the standard derivation of the logarithm of SAIDI were used as input parameters in the development of SAIDI threshold model. The result of the research paper shows that the SAIDI threshold values fluctuate over the years with the least and highest SAIDI threshold values as 2.11596 and 4.62518 respectively which were recorded in the months of September and April. The SAIDI thresholds in the months of January, February, March, April, May and June are 3.18318, 3.32458, 4.22242, 4.62518, 2.71360 and 3.27760 respectively suggesting an indefinite pattern in the SAIDI threshold as a result of unexpected interruptions experienced by customers attached to the distribution feeders. SAIDI threshold forms a basis for power system planning and maintenance strategies.

scholarly journals The Impact of Energy Storage along with the Allocation of RES on the Reduction of Energy Costs Using MILP

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3783
Author(s):  
Mateusz Andrychowicz
Keyword(s):  
Energy Storage ◽  
Mixed Integer Linear Programming ◽  
Distribution Systems ◽  
Operating Costs ◽  
Mixed Integer ◽  
Energy Costs ◽  
Power Exchange ◽  
Local Initiatives ◽  
One Year ◽  
The Impact

The paper shows a method of optimizing local initiatives in the energy sector, such as energy cooperatives and energy clusters. The aim of optimization is to determine the structure of generation sources and energy storage in order to minimize energy costs. The analysis is carried out for the time horizon of one year, with an hourly increment, taking into account various RES (wind turbines (WT), photovoltaic installations (PV), and biogas power plant (BG)) and loads (residential, commercial, and industrial). Generation sources and loads are characterized by generation/demand profiles in order to take into account their variability. The optimization was carried out taking into account the technical aspects of the operation of distribution systems, such as power flows and losses, voltage levels in nodes, and power exchange with the transmission system, and economic aspects, such as capital and fixed and variable operating costs. The method was calculated by sixteen simulation scenarios using Mixed-Integer Linear Programming (MILP).

scholarly journals Modeling Bacterial Regrowth and Trihalomethane Formation in Water Distribution Systems

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 463
Author(s):  
Gopinathan R. Abhijith ◽  
Leonid Kadinski ◽  
Avi Ostfeld
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Mechanistic Model ◽  
Water Distribution Systems ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
Growth Rate Constant ◽  
Model Parameters ◽  
Bacterial Regrowth ◽  
The Impact

The formation of bacterial regrowth and disinfection by-products is ubiquitous in chlorinated water distribution systems (WDSs) operated with organic loads. A generic, easy-to-use mechanistic model describing the fundamental processes governing the interrelationship between chlorine, total organic carbon (TOC), and bacteria to analyze the spatiotemporal water quality variations in WDSs was developed using EPANET-MSX. The representation of multispecies reactions was simplified to minimize the interdependent model parameters. The physicochemical/biological processes that cannot be experimentally determined were neglected. The effects of source water characteristics and water residence time on controlling bacterial regrowth and Trihalomethane (THM) formation in two well-tested systems under chlorinated and non-chlorinated conditions were analyzed by applying the model. The results established that a 100% increase in the free chlorine concentration and a 50% reduction in the TOC at the source effectuated a 5.87 log scale decrement in the bacteriological activity at the expense of a 60% increase in THM formation. The sensitivity study showed the impact of the operating conditions and the network characteristics in determining parameter sensitivities to model outputs. The maximum specific growth rate constant for bulk phase bacteria was found to be the most sensitive parameter to the predicted bacterial regrowth.

scholarly journals Electric Vehicles in Jordan: Challenges and Limitations

2021 ◽  
Vol 13 (6) ◽  
pp. 3199
Author(s):  
Laith Shalalfeh ◽  
Ashraf AlShalalfeh ◽  
Khaled Alkaradsheh ◽  
Mahmoud Alhamarneh ◽  
Ahmad Bashaireh
Keyword(s):  
Electric Vehicles ◽  
Distribution System ◽  
Distribution Systems ◽  
Environmental Benefits ◽  
System Stability ◽  
Loading Conditions ◽  
Stability Margins ◽  
High Penetration ◽  
Node Distribution ◽  
The Impact

An increasing number of electric vehicles (EVs) are replacing gasoline vehicles in the automobile market due to the economic and environmental benefits. The high penetration of EVs is one of the main challenges in the future smart grid. As a result of EV charging, an excessive overloading is expected in different elements of the power system, especially at the distribution level. In this paper, we evaluate the impact of EVs on the distribution system under three loading conditions (light, intermediate, and full). For each case, we estimate the maximum number of EVs that can be charged simultaneously before reaching different system limitations, including the undervoltage, overcurrent, and transformer capacity limit. Finally, we use the 19-node distribution system to study these limitations under different loading conditions. The 19-node system is one of the typical distribution systems in Jordan. Our work estimates the upper limit of the possible EV penetration before reaching the system stability margins.

scholarly journals A new meta-heuristic pathfinder algorithm for solving optimal allocation of solar photovoltaic system in multi-lateral distribution system for improving resilience

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Varaprasad Janamala
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Voltage Stability ◽  
Optimal Allocation ◽  
Photovoltaic System ◽  
Solar Photovoltaic ◽  
Voltage Profile ◽  
Pv System ◽  
Solar Photovoltaic System ◽  
The Impact

AbstractA new meta-heuristic Pathfinder Algorithm (PFA) is adopted in this paper for optimal allocation and simultaneous integration of a solar photovoltaic system among multi-laterals, called interline-photovoltaic (I-PV) system. At first, the performance of PFA is evaluated by solving the optimal allocation of distribution generation problem in IEEE 33- and 69-bus systems for loss minimization. The obtained results show that the performance of proposed PFA is superior to PSO, TLBO, CSA, and GOA and other approaches cited in literature. The comparison of different performance measures of 50 independent trail runs predominantly shows the effectiveness of PFA and its efficiency for global optima. Subsequently, PFA is implemented for determining the optimal I-PV configuration considering the resilience without compromising the various operational and radiality constraints. Different case studies are simulated and the impact of the I-PV system is analyzed in terms of voltage profile and voltage stability. The proposed optimal I-PV configuration resulted in loss reduction of 77.87% and 98.33% in IEEE 33- and 69-bus systems, respectively. Further, the reduced average voltage deviation index and increased voltage stability index result in an improved voltage profile and enhanced voltage stability margin in radial distribution systems and its suitability for practical applications.

scholarly journals “You run out of hope:” An Exploration of Low-Income Parents’ Experiences with Food Insecurity using Photovoice

2021 ◽  
pp. 1-21
Author(s):  
Payge Lindow ◽  
Irene H. Yen ◽  
Mingyu Xiao ◽  
Cindy W. Leung
Keyword(s):  
Food Insecurity ◽  
San Francisco ◽  
Low Income ◽  
Eating Behaviors ◽  
Comparative Method ◽  
Well Being ◽  
Structured Interviews ◽  
Unhealthy Eating ◽  
Low Income Families ◽  
The Impact

ABSTRACT Objective: Using an adaption of the Photovoice method, this study explored how food insecurity affected parents’ ability to provide food for their family, their strategies for managing household food insecurity, and the impact of food insecurity on their well-being. Design: Parents submitted photos around their families’ experiences with food insecurity. Afterwards, they completed in-depth, semi-structured interviews about their photos. The interviews were transcribed and analyzed for thematic content using the constant comparative method. Setting: San Francisco Bay Area, California, USA. Subjects: 17 parents (14 mothers and 3 fathers) were recruited from a broader qualitative study on understanding the experiences of food insecurity in low-income families. Results: Four themes were identified from the parents’ photos and interviews. First, parents described multiple aspects of their food environment that promoted unhealthy eating behaviors. Second, parents shared strategies they employed to acquire food with limited resources. Third, parents expressed feelings of shame, guilt, and distress resulting from their experience of food insecurity. And finally, parents described treating their children to special foods to cultivate a sense of normalcy. Conclusions: Parents highlighted the external contributors and internal struggles of their experiences of food insecurity. Additional research to understand the experiences of the food-insecure families may help to improve nutrition interventions targeting this structurally vulnerable population.

scholarly journals Standing on the shoulders of Giants: a citation analysis of the paediatric congenital heart disease literature

2021 ◽  
pp. 1-9
Author(s):  
Daniel P. Sew ◽  
Nigel E. Drury
Keyword(s):  
Citation Analysis ◽  
San Francisco ◽  
Citation Count ◽  
Case Series ◽  
Scientific Progress ◽  
The United States ◽  
Original Research ◽  
Prolific Author ◽  
Journal Citation Reports ◽  
The Impact

Abstract Objective: The citation history of a published article reflects its impact on the literature over time. We conducted a comprehensive bibliometric analysis to identify the most cited papers on CHD in children. Methods: One-hundred and ninety journals listed in Journal Citation Reports were accessed via Web of Science. Publications with 250 or more citations were identified from Science Citation Index Expanded (1900–2020), and those relating to structural CHD in children were reviewed. Articles were ranked by citation count and the 100 most cited were analysed. Results: The number of citations ranged from 2522 to 309 (median 431, IQR 356–518), with 35 published since 2000. All were written in English, most originated from the United States (74%), and were published in cardiovascular journals, with Circulation (28%) the most frequent. There were 86 original research articles, including 50 case series, 14 cohort studies, and 10 clinical trials. The most cited paper was by Hoffman JI and Kaplan S on the incidence of CHD. Thirteen authors had 4 or more publications in the top 100, all of whom had worked in Boston, Philadelphia, San Francisco, or Dallas, and the most prolific author was Newburger JW (9 articles). Conclusions: Citation analysis provides a historical perspective on scientific progress by assessing the impact of individual articles. Our study highlights the dominant position of US-based researchers and journals in this field. Most of the highly cited articles remain case series, with few randomised controlled trials in CHD appearing in recent years.

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