Distribution System Infrastructure Research Articles

Potential Public Health Impacts of Deteriorating Distribution System Infrastructure.

Drinking water distribution system deterioration can affect the water supply and reliability as well as water quality and public health.

A Stochastic Model Predictive Control Approach for Joint Operational Scheduling and Hourly Reconfiguration of Distribution Systems

Due to the recent developments in the practical implementation of remotely controlled switches (RCSs) in the smart distribution system infrastructure, distribution system operators face operational challenges in the hourly reconfigurable environment. This paper develops a stochastic Model Predictive Control (MPC) framework for operational scheduling of distribution systems with dynamic and adaptive hourly reconfiguration. The effect of coordinated integration of energy storage systems and demand response programs through hourly reconfiguration on the total costs (including cost of total loss, switching cost, cost of bilateral contract with power generation owners and responsive loads, and cost of exchanging power with the wholesale market) is investigated. A novel Switching Index (SI) based on the RCS ages and critical points in the network along with the maximum number of switching actions is introduced. Due to nonlinear nature of the problem and several existing binary variables, it is basically considered as a Mixed Integer Non-Linear Programming (MINLP) problem, which is transformed into a Mixed Integer Linear Programming (MILP) problem. The satisfactory performance of the proposed model is demonstrated through its application on a modified IEEE 33-bus distribution system.

The origin and risks associated with loose deposits in a drinking water distribution system

Abstract Sediment accumulates in distribution systems over time, and can potentially result in dirty water events. The primary origin of these particles in most networks has not been examined. Controlled sediment resuspension (flushing) events were performed at 10 sites in a drinking water distribution system and repeated six months later to observe redeposition. Different patterns of sediment deposition observed are suspected to be related to particle origin. A large proportion of pipe sediment resuspended during the first flushing event was composed of iron, most likely arising from corrosion of distribution system infrastructure. This sediment appears to play a role in sheltering microbial cells from secondary disinfection. In this study, a source of particles was identified that may provide an alternate explanation for the presence of iron deposits in systems not dominated by iron pipework.

Investigation of THD Analysis in Residential Distribution Systems with Different Penetration Levels of Electric Vehicles

Electric Vehicles (EVs) are becoming a viable transportation option because they are environmentally friendly and provide solutions to high oil prices. This paper investigates the impacts of electric vehicles on harmonic distortions in urban radial residential distribution systems. The accomplishment of EV innovation relies on the accessibility of EV charging stations. To meet the power demand of growing EVs, utilities are introducing EV charging stations in private and public areas; this led to a change in the residential distribution system infrastructure. In this paper, an urban radial residential distribution system with the integration of an electric vehicle charging facility is considered for investigation. An impact of different EV penetration levels on voltage distortion is analysed. Different penetration levels of EVs into the residential distribution system are considered. Simulation results are presented to validate the work carried out in this paper. An attempt has been made to establish the relationship between the level of penetration of the EVs and voltage distortion in terms of THD (Total Harmonic Distortion)

Smart Charging Strategies for Optimal Integration of Plug-In Electric Vehicles Within Existing Distribution System Infrastructure

In this paper, smart charging strategies incorporating a unified grid-to-vehicle and vehicle-to-grid charging framework are proposed for optimal integration of plug-in electric vehicles (PEVs) within the existing distribution system infrastructure. Two smart strategies with objective functions considering minimization of total daily cost and peak-to-average ratio, respectively, are developed to study the impact on PEV charging from an economic and technical perspective. The proposed strategies are implemented for PEV charging at workplace car parks located in a 37-bus distribution system and an analytical study is presented to evaluate the maximum possible PEV penetration that the existing distribution infrastructure can accommodate corresponding to the two strategies. A comparative analysis of the two strategies is performed in terms of various economic and technical benefits that are derived. Moreover, a performance comparison of the two strategies in presence of slow and fast charging of PEVs is also presented. Finally, an investigative study is conducted for both the strategies to evaluate the maximum PEV penetration that can be integrated in the upcoming years without infrastructure reinforcement. The simulation results present a comprehensive evaluation of the two proposed strategies.

Tools for Distributed Systems Monitoring

Abstract The management of distributed systems infrastructure requires dedicated set of tools. The one tool that helps visualize current operational state of all systems and notify when failure occurs is available within monitoring solution. This paper provides an overview of monitoring approaches for gathering data from distributed systems and what are the major factors to consider when choosing a monitoring solution. Finally we discuss the tools currently available on the market.

Biofouling potential and material reactivity in a simulated water distribution network supplied with stormwater recycled via managed aquifer recharge

The injection of stormwater into aquifers for storage and recovery during high water demand periods is a promising technology for augmenting conventional water reserves. Limited information exists regarding the potential impact of aquifer treated stormwater in distribution system infrastructure. This study describes a one year pilot distribution pipe network trial to determine the biofouling potential for cement, copper and polyvinyl chloride pipe materials exposed to stormwater stored in a limestone aquifer compared to an identical drinking water rig. Median alkalinity (123 mg/L) and colour (12 HU) in stormwater was significantly higher than in drinking water (82 mg/L and 1 HU) and pipe discolouration was more evident for stormwater samples. X-ray Diffraction and Fluorescence analyses confirmed this was driven by the presence of iron rich amorphous compounds in more thickly deposited sediments also consistent with significantly higher median levels of iron (∼0.56 mg/L) in stormwater compared to drinking water (∼0.17 mg/L). Water type did not influence biofilm development as determined by microbial density but faecal indicators were significantly higher for polyvinyl chloride and cement exposed to stormwater. Treatment to remove iron through aeration and filtration would reduce the potential for sediment accumulation. Operational and verification monitoring parameters to manage scaling, corrosion, colour, turbidity and microbial growth in recycled stormwater distribution networks are discussed.

A Fish “Tale”

As we work to solve today's lead‐in‐water crisis, we also need to think about how to use this moment to build support to solve other contributing water challenges. Ultimately many of those challenges wind their way back to the importance of reinvesting in water's distribution system infrastructure.

Pipe to Pipe to Pipe

It's all about the pipe. Of course, distribution systems consist of far more than just pipelines. However, when it comes to replacing distribution system infrastructure, the big expense is replacing at‐risk pipe. In fact, the most expensive thing we do in the water business is lay pipe in the ground. Forget the capital cost of treatment processes. Add up the pipe replacement cost for virtually any retail water agency and it dwarfs ‐ by a lot ‐ the capital cost of treatment. In fact, the needed financial resources to replace aging pipes and other infrastructure is the top concern expressed by survey participants in the State of the Water Industry report in this issue.

Fundamentals of stream processing: application design, systems, and analytics

Stream processing is a novel distributed computing paradigm that supports the gathering, processing, and analysis of high-volume, heterogeneous, continuous data streams, to extract insights and actionable results in real time. This comprehensive, hands-on guide combining the fundamental building blocks and emerging research in stream processing is ideal for application designers, system builders, analytic developers, as well as students and researchers in the field. This book introduces the key components of the stream computing paradigm, including the distributed system infrastructure, the programming model, design patterns, and streaming analytics. The explanation of the underlying theoretical principles, illustrative examples and implementations using the IBM InfoSphere Streams SPL language, and real-world case studies provide students and practitioners with a comprehensive understanding of such applications and the middleware that supports them.

Methodological approach for the optimization of drinking water treatment plants' operation: a case study.

Critical barriers to safe and secure drinking water may include sources (e.g. groundwater contamination), treatments (e.g. treatment plants not properly operating) and/or contamination within the distribution system (infrastructure not properly maintained). The performance assessment of these systems, based on monitoring, process parameter control and experimental tests, is a viable tool for the process optimization and water quality control. The aim of this study was to define a procedure for evaluating the performance of full-scale drinking water treatment plants (DWTPs) and for defining optimal solutions for plant upgrading in order to optimize operation. The protocol is composed of four main phases (routine and intensive monitoring programmes - Phases 1 and 2; experimental studies - Phase 3; plant upgrade and optimization - Phase 4). The protocol suggested in this study was tested in a full-scale DWTP placed in the North of Italy (Mortara, Pavia). The results outline some critical aspects of the plant operation and permit the identification of feasible solutions for the DWTP upgrading in order to optimize water treatment operation.

Distributed Electronic Commerce cluster for small enterprise

The Electronic Commerce System should provide prompt responses for user requests and continuous services despite partial failures of its sub systems. In addition, scalability and flexibility should be supported as the number of customers increases. Because Electronic Commerce is beyond the national border, the system should be implemented across different subnets for its efficiency and business needs. This paper proposes the design and implementation of a distributed system infrastructure across different subnets for Electronic Commerce. When the Electronic Commerce system is owned and managed by a small enterprise, the cost should be considered as well as fault tolerance, high availability and scalability. The proposed infrastructure was evaluated and discussed in the aspect of economics such as implementation and management cost, performance and overhead.

Preventing the Perfect Storm: Public Health Relies on Risk Management

This article discusses the simultaneous occurrence of certain events that can cause a major disaster in a utility's distribution system. Specifically, the article discusses the top four concerns for distribution systems, as indicated by actual records of contamination and waterborne disease outbreaks, including: cross‐connections and backflow of contaminated water; contamination resulting from storage facility design, operation, or maintenance; contamination caused by main installation, repair, or rehabilitation practices; and, contaminant intrusion caused by pressure conditions and physical gaps in distribution system infrastructure.

Probabilistic approach for optimal allocation of wind-based distributed generation in distribution systems

Recent development in small renewable/clean generation technologies such as wind turbines, photovoltaic, fuel cells, microturbines and so on has drawn distribution utilities' attention to possible changes in the distribution system infrastructure and policy by deploying distributed generation (DG) in distribution systems. In this study, a methodology has been proposed for optimally allocating wind-based DG units in the distribution system so as to minimise annual energy loss. The methodology is based on generating a probabilistic generation–load model that combines all possible operating conditions of the wind-based DG units and load levels with their probabilities, hence accommodating this model in a deterministic planning problem. The planning problem is formulated as mixed integer non-linear programming (MINLP), with an objective function for the system's annual energy losses minimise. The constraints include voltage limits at different buses (slack and load buses) of the system, feeder capacity, discrete size of the DG units, maximum investment on each bus, and maximum penetration limit of DG units. This proposed technique is applied to a typical rural distribution system and compared to the traditional planning technique (constant output power of DG units and constant peak load profile).

Magnetic Fields Produced by Underground Residential Distribution System

Increasingly dense residential housing developments have spurred new concerns about electromagnetic fields. The magnetic fields generated by the underground distribution system in such a residential subdivision are assessed in this study. In particular, the magnetic flux densities above the underground cables, around the padmount transformers and junction boxes, and at the service entrance panels are measured. The largest magnetic fields of 95 mG and 148 mG are recorded on the surfaces of the transformer enclosures and junction boxes, respectively, at around 30% to 40% of full load. The magnetic fields reduce to less than 3 mG at a distance of ~1 m from the distribution system infrastructure. Software is developed to estimate the peak magnetic field generated at full load conditions by the underground cables composed of twisted conductors.

The Drinking Water State Revolving Fund Helps Ground Water Systems Deliver Public Health Protection

The Drinking Water State Revolving Fund Helps Ground Water Systems Deliver Public Health Protection

BBN's Network Computing Software Infrastructure and Distributed Applications (1970-1990)

From the early 1970s, developers at Bolt Beranek and Newman continued BBN's record for innovative breakthroughs in networked systems. In this article the author review highlights of BBN's history in the area of distributed computing from several different perspectives: early investigations into how to make use of and program the emerging interhost communication capability, distributed systems infrastructure (middleware), and network-centric applications that utilized the emerging distributed systems capabilities in new and innovative ways.

An agent-based approach for coordinating product design workflows

New product development processes in manufacturing organizations are distributed and knowledge-intensive. Such product development processes interleave complex manual and software-enabled design decision-making activities. In current approaches to product development, design activities are accomplished by teams of engineers in an ad hoc, resource-intensive manner. Though well-developed tools exist for enabling individual engineering activities, support for autonomous coordination of distributed design tasks is minimal. In this paper, we present an Agent-based Process Coordination (APC) framework for distributed design process management. The proposed approach embeds autonomous agents in a workflow-based distributed systems infrastructure. The framework utilizes a centralized decision-making and task sharing approach to support design activities. A design process plan is executed by a centralized coordination agent with the help of service agents. We evaluate the applicability of the APC framework to support design in an industrial context with a case study. The study illustrates the utility of deploying agent-based workflow technologies to: (a) enable incremental and large-scale process and product knowledge acquisition and management, (b) facilitate design process knowledge reuse in different contexts, and (c) support distributed dynamic process management.

Delivery methods and design in 2050

Will the future be gloomy? Current indications forecast a gloomy future in which water will become even more scarce. Global warming will increase salts in coastal waters. Energy prices will continue to rise, causing an exponential increase in the cost of water. Minimizing water losses through the distribution system and maximizing water conservation techniques will be critical. Distribution system infrastructure will be replaced through a national water tax or trust fund.

Guest Editor's introduction: Special issue on distributed virtual environments

Guest Editor's introduction: Special issue on distributed virtual environments