Loading...
Search for:
distribution-networks
0.013 seconds
Total 176 records
Caching in Information Centric Software Defined Networks
,
M.Sc. Thesis
Sharif University of Technology
;
Pakravan, Mohammad Reza
(Supervisor)
Abstract
Data traffic in communication network has increased steadily in recent years. Service requirements have also changed to become more complex. Moreover decrease in relative prices of computation and storage against communication encourages using more caching in these networks . Meanwhile increased use of encryption in internet has forced service providers who were willing to enter content distribution market to cooperate with content providers. But the cooperation is discouraged by willingness of both parties to hide their internal information. There are solutions proposed for interaction and information exchange between ISPs and CPs which are based on game theory. However, these solutions...
Developing a Control Algorithm for the new Power Quality Device (HPFC)
, M.Sc. Thesis Sharif University of Technology ; Mokhtari, Hossein (Supervisor)
Abstract
Non-linear loads have been increasing in industries resulting in high levels of harmonics in power networks. Harmonics have several negative effects including higher energy losses and lifespan reduction in equipment due to thermal loss. To reduce the levels of harmonics and consequently reduce the losses in power networks different methods of harmonic suppression have been employed. These methods are normally used at the customer’s side. In all of these methods, the idea is to prevent harmonics from flowing into a power network at the Point of Common Coupling (PCC). This research tries to reduce the harmonic losses by controlling the harmonic flow in a power network. Therefore, the solution...
A Comprehensive Scheme for Reliability-Centered Asset Management Implementation in Power Distribution Systems
, M.Sc. Thesis Sharif University of Technology ; Fotuhi Firuzabad, Mahmoud (Supervisor)
Abstract
Toward the cost-effective solutions for the challenging features of maintenance in nowadays restructured power systems, reliability centered maintenance (RCM) has been introduced as the efficient key due to its streamlined performance. RCM, although has proven its noticeable merits in many industries, has not been yet furnished with efficient analytical methods in the power engineering context. In a power distribution system, vividly in a deregulated market and restructured environment, blind time based maintenance of all the distribution equipments is neither affordable nor economically justifiable. Moreover, an acceptable level of system reliability is an indispensable criterion for the...
Residential Demand Response Coordination to Enhance Network Reliability
, M.Sc. Thesis Sharif University of Technology ; Fotuhi Firouzabad, Mahmud (Supervisor)
Abstract
Residential demand response is an appropriate control tool for improving system reliability. This project intends to establish a model to activate residential demand response to improve distribution network reliability. Two centralized and decentralized models are proposed. The models aim at minimizing the damage cost imposed by load curtailments following unexpected events. In the models, it is supposed that distribution system operator (DSO) and responsive customers already signed a contract authorizing the DSO alters the operation of responsive appliances whenever system reliability is jeopardized. In centralized framework, Responsive customers deliver the technical data of their...
Efficient and Economic Reliability Target Setting and Legislation in Electric Power Distribution Systems
, M.Sc. Thesis Sharif University of Technology ; Fotuhi Firuzabad, Mahmud (Supervisor)
Abstract
A high percentage of power grid faults occur in the distribution sector, which causes customers to experience power outages. In order to maintain a good reputation with customers and maximize their satisfaction, improving the reliability of the services provided in the electricity distribution network and minimizing related costs have always been one of the most important challenges for electricity network managers. Therefore, managers and legislators of the power network are always looking for a way to maintain the reliability level of the power distribution network and also to improve it. So far, many researchers have focused on setting goals with the help of average performance methods...
Distribution Load Modeling Incorporating Distributed Generations and Studying its Side Effects
, M.Sc. Thesis Sharif University of Technology ; Fotuhi-Firuzabad, Mahmud (Supervisor)
Abstract
According to the economic and environmental considerations, the use of distributed generation, both renewable and non-renewable type, in distribution networks is increasing. Their power generation is determined either by weather conditions or customers’ control due to their needs, therefore it is beyond the control of dispatcher.
In this thesis, two common technologies of distributed generations, including wind turbines and micro-CHPs, have been considered and the effects of their generations and penetrations on distribution network load and other network parameters have been evaluated.
Power generation of micro-CHP units and its side effects, is dependent on the customers’...
In this thesis, two common technologies of distributed generations, including wind turbines and micro-CHPs, have been considered and the effects of their generations and penetrations on distribution network load and other network parameters have been evaluated.
Power generation of micro-CHP units and its side effects, is dependent on the customers’...
Probabilistic Modeling of Water Distribution Infrastructure and Its Inter- Dependencies in Community Resilience Analysis
, M.Sc. Thesis Sharif University of Technology ; Mahsuli, Mojtaba (Supervisor) ; Safaie, Ammar (Co-Supervisor)
Abstract
This research develops a probabilistic framework for evaluating community resilience subject to earthquake events by modeling the water distribution system and its prevailing inter- and intra-dependencies with other infrastructure systems of the community. This framework is entitled “Rtx,” which is under continuous development at the Center for Infrastructure Sustainability and Resilience Research (INSURER) at Sharif University of Technology, Tehran, Iran. It quantifies the community resilience by integrating hazard models, risk models, and recovery models within an agent-based simulation. Comprehensive modeling of the water distribution system requires a library of probabilistic models,...
Simultaneous Group Membership with Members Collaboration in Wireless Networks Using Hierarchical Approach
, M.Sc. Thesis Sharif University of Technology ; Nemaney Pour, Alireza (Supervisor)
Abstract
Recently, demand for using variant applications in distributed networks has been increased largely. Most of these applications are based on group communication.In distributed group communication, two important factors need to be considered, group construction, and Group Key Management (GKM). The group construction specifies the process of constructing a new group by cooperation between distributed users. As well, GKM ensures re-freshness of the group key after each join/leave operation. Both of these tasks must be done by collaboration between members. This leads to imposing complexity and communication overhead to the system.This thesis proposes efficient methods for group construction and...
Designing a Reward-Penalty Scheme to Improve Technical Performance of Distribution System Employing Distributed Generation (DG) Resources
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehranifard, Ali (Supervisor) ; Fotuhi Firuzabad, Mahmud (Supervisor)
Abstract
Reward-penalty schemes are known as the most effective tools to regulate the service quality. This thesis tries to design a comprehensive reward-penalty scheme to properly motivate electricity distribution companies (DisCos) to improve the reliability and reduce the energy losses in their networks using Distributed Generation (DG) Resources. So, as the first step, the designing methods of reward-penalty scheme (RPS) and their advantage and disadvantages are introduced, and also a method based on concept of the Yaredestic theory is proposed. The proposed method uses the Fuzzy clustering and is able to set the parameters of RPS in a fair and efficient way. The proposed RPS is implemented on...
Design and Analysis of Low-Power VLSI Clock Distribution Networks, Considering Process Variations
,
M.Sc. Thesis
Sharif University of Technology
;
Sarvari, Reza
(Supervisor)
Abstract
The Technology scaling and reduction of the size of transistors has led to an increase in the switching speed and, as a result, to an increase in the clock frequency.But in recent years, the continuation of this process of increasing the clock frequency has been almost stopped considering the considerations of power consumption. Previous research has shown that approximately 30-50% of the dynamic power consumed by the microprocessor is wasted in the clock distribution network.Therefore, the design of clock distribution networks is a big challenge for future microprocessors due to the trend of Technology scaling and process variation. In this thesis, we used the emerging technology of...
Design of Incentive Scheme for Reliability Improvement in Electricity Distribution Networks
, Ph.D. Dissertation Sharif University of Technology ; Fotuhi Firuzabad, Mahmoud (Supervisor)
Abstract
The regulation is necessary for the electric distribution networks as a natural monopoly. Regulators have been applied the Performance Based Regulation (PBR) for the control of price. The common model of PBR is price cap. Price cap creates sufficient incentive for cost efficiency. However, it decreases the service quality in distribution systems. The aim of this thesis is to design a comprehensive model for improvement of service reliability in the presence of PBR. An incentive model is developed using reward-penalty theory and yardstick theory. Reward-penalty theory is a financial approach that rewards the utility with good reliability and penalizes the utility with poor reliability. The...
Optimal Design of Price Based Demand Response Programs in Distribution Networks
, Ph.D. Dissertation Sharif University of Technology ; Fotuhi-Firuzabad, Mahmud (Supervisor) ; Lehtonen, Matti (Co-Advisor)
Abstract
The major goal of the power industry is to serve the demand of electricity consumers as reliable as possible but at an affordable cost. Towards the goal, however, the industry faces substantial barriers such as aging infrastructures, growing demand, and limited budgets for reinforcements. A great portion of infrastructures which were built decades ago need to be retired. The growing demand needs system reinforcement and expansion. These, in turn, require considerable amounts of investment which is in contradiction with highly limited budget of the power industry. This critical situation forces the industry to utilize the existing system more efficiently and wisely. To this end, the concept...
Supply Chain Network with Normal Demand
, M.Sc. Thesis Sharif University of Technology ; Modarres Yazdi, Mohammad (Supervisor)
Abstract
In this thesis, we focus on some internal organization issues of the supply chain; in particular, we analyze some network design problems which are typical of producer companies. The aim is to optimize the flow of goods through the literature distribution network, from the plants where the goods are produced (supply points) to the demand points, which are essentially distributors such as wholesalers or retailers. The system addresses a class of distribution network design problems, which is characterized by multiple product families, a central manufacturing plant site, multiple central warehouses and distribution center, and retail outlets (customer zones) which demand multiple units of...
Intrusion Detection System in Smart Grids
, M.Sc. Thesis Sharif University of Technology ; Amini, Morteza (Supervisor)
Abstract
Smart grids are the new generation of power grids that combine the power distribution grid with the communications network. The purpose of these networks is to create a secure, two-way infrastructure for the transmission of power and information. The complex structure of smart grids, along with the inherent vulnerabilities of physical systems, old devices and protocols on the network and the need for backward compatibility, have created serious cyber risks to critical assets and infrastructures. The difference between these types of networks and conventional computer networks has made the security mechanisms developed in conventional computer networks not very suitable for these types of...
Optimal Placement of fault Indicator and Switch in Distribution Network Simultaneously
, M.Sc. Thesis Sharif University of Technology ; Vakilian, Mehdi (Supervisor)
Abstract
The price that customers pay for electric energy is determined by cost of generation, transmission and distribution parts. In Practice all customer have main concern about reliability of electric energy, because of it’s major effect on different aspect of life. Although customers are interested to have fully reliable service, but power companies are aware that it is impossible to achieve this goal from technical and economical aspect. The utilities and customer benefits can be achieved through minimization of the total investment cost of network, while improving the reliability and quality of electric service. This also requires to minimize the customers service interruption time. To meet...
Developing a Framework for Assessment and Optimal Enhancement of Multi-Microgrid Distribution System Reliability
, M.Sc. Thesis Sharif University of Technology ; Abbaspour, Ali (Supervisor) ; Fotuhi Firuzabad, Mahmud (Co-Supervisor)
Abstract
Issues related to the environmental pollution, greenhouse gas emissions, as well as the limited supply of fossil fuels and their rising prices have led to the deployment of distributed energy technologies in power systems. With the increasing penetration of distributed energy sources in distribution systems, smart grids, and in particular, microgrids have emerged as a suitable and widely accepted solution for controlling and utilizing these resources. Microgrids can enhance energy efficiency in a sustainable power grid as well as the reliability of the distribution system, through supporting high penetration of renewable energy sources and providing island performance.In view of growing...
Development of the Power Supply System's Resilience Model (Case Study: Khusestan Province Electrical Grid)
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
The purpose of the current study is developing an evaluation model for the electrical grid. Resilience is an approach toward risk management against disorders and protecting the system during critical conditions. The importance of resilience assessment, especially in crucial infrastructures, has always been at the center of attention. Nonetheless, previous studies in this field were mostly limited to micro-scales, meaning that only a limited part of the system was evaluated. Therefore, such studies rely on technical data and system details. This issue renders macro-scale assessments challenging. Some of the models, which are based on analytical-statistical methods, examine the systems at...
Determiniation of Optimal Interruptible Load Contracts in Smart Distribution Networks Considering Reliability Indices
, M.Sc. Thesis Sharif University of Technology ; Fotuhi Firouzabad, Mahmud (Supervisor)
Abstract
Nowadays, considering the dependence of the life quality to the electric energy, exhaustion of the existing facilities in the distribution networks, and restructuring of the electric industry, the reliability improvement turns out to be one of the most important considerations in order to reducing the operational cost. Furthermore, the expansion of existing networks, substitution, and refinement of the exhausted facilities for improving the reliability can lead to remarkable expenses. Considering the limitations of budgets of distribution network companies, these plans cannot be put into practice. Therefore, operators and planners of this industry have to find ways to operate the existing...
Optimum Location of Re-closers, and Fault Indicators in a Distribution Network for Improvement of Reliability Parameters
, M.Sc. Thesis Sharif University of Technology ; Vakilian, Mahdi (Supervisor)
Abstract
Nowadays, due to the indensible role of electrical energy in life of societies, the reliability of service should be provided in an economic form. Researches has shown that, about 80% of faults occur in the distribution network. In a distribution network that is equipped with automation systems, through the acceleration in the determination of the fault location, and also possibility of reacting against transient and steady faults, the electricity interruption time duration is minimized. This thesis aims to determine the number and to locate the auto reclosers and fault indicators in a distribution network optimally. To make it economically feasible, a limited number of these devices and...
Phase Identification and Balancing in LV Distribution Networks Using Smart Meters Data
, M.Sc. Thesis Sharif University of Technology ; Safdarian, Amir (Supervisor)
Abstract
With the rapid proliferation of residential rooftop photovoltaic (PV) systems, current and voltage unbalance issues have become a matter of great concern in low voltage (LV) distribution feeders. This, however, necessitates identification of the hosting phase of the connected single-phase customers and PV panels. Both of the challenges have been addressed in this thesis. In the first place, this thesis proposes a mixed integer linear programming (MILP) model for phase identification problem. The model considers potential error in the input data provided by smart meters. To mitigate negative impacts of the error, the data associated with several consecutive time intervals are taken into...