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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Some Aspects of Microgrid Planning and Optimal Distribution Operation in the Presence of Electric Vehicles

Hafez, Omar 20 December 2011 (has links)
Increase in energy demand is one of the major challenges that utilities are faced with, thus resulting in an increase in environmental pollution and global warming. The transport sector has a significant share of the energy demand and is a major contribution of emissions to the environment. In Canada, almost 35% of the total energy demand is from the transport sector and it is the second largest source of greenhouse gas (GHG) emissions. The government of Ontario has aimed to move toward a green energy economy, thus resulting in increased penetration of renewable energy sources as well as Plug-in hybrid electric vehicle (PHEV) technology. Penetration of renewable energy sources into microgrids are gradually being recognized as important alternatives in supply side planning. This thesis focuses on the optimal design, planning, sizing and operation of a hybrid, renewable energy based microgrid with the goal of minimizing the lifecycle cost, while taking into account environmental emissions. Four different configurations including a diesel-only, a fully renewable-based, a diesel-renewable mixed, and an external-grid connected microgrid are designed, to compare and evaluate their economics, operational performance and environmental emissions. Analysis is also carried out to determine the break-even economics for a grid-connected microgrid. The well-known energy modeling software for hybrid renewable energy systems, HOMER, is used in the studies reported in this thesis. An optimal power flow (OPF) based optimization framework considering two different objectives, minimizing feeder losses and PHEV charging cost, are presented to understand the impact of PHEV charging on distribution networks. Three different charging periods are considered and the impact of the Ontario Time-of-Use (TOU) tariff on PHEV charging schedules is examined. The impact of PHEV charging on distribution systems in the presence of renewable energy sources is discussed by extending the developed OPF based model to include the contribution of renewable energy sources. The proposed model is evaluated under a variety of scenarios.
2

Modeling, Simulation and Optimization of Residential and Commercial Energy Systems

Bregaw, Mohamed Abdussalam 12 August 2013 (has links)
A Residential Energy Management System (REMS) in smart grid provides capability to manage a daily load curve in order to reduce power consumption and energy cost. Consequently, (REMS) offers significant benefits for both the electricity suppliers and consumers in terms of control and schedule time of use of major appliances. In recent years, however, the rate of energy demand has increased rapidly throughout the world while the price of energy has been fluctuating. Numerous methods for (REMS) are used; this thesis analyzes many candidate scenarios during peak load periods comparing to the tariff to reduce the usage and its associated costs. It presents simulated results of proposed (REMS) to provide an automated least cost demand response. The main approach will be to ensure the satisfaction of the requirements with constraints on efficient use of energy. Multiphasic system behaviors of smart appliances in (REMS) with a realistic manner are proposed. / This thesis examines many mathematical models of home appliances in order to calculate the physical quantities that reflect the parameters’ impact and the system behavior. Main contribution determines the optimal solution of (TOU) problem to reduce energy cost and determine the best operation time by using (Linear optimization technique).
3

Some Aspects of Microgrid Planning and Optimal Distribution Operation in the Presence of Electric Vehicles

Hafez, Omar 20 December 2011 (has links)
Increase in energy demand is one of the major challenges that utilities are faced with, thus resulting in an increase in environmental pollution and global warming. The transport sector has a significant share of the energy demand and is a major contribution of emissions to the environment. In Canada, almost 35% of the total energy demand is from the transport sector and it is the second largest source of greenhouse gas (GHG) emissions. The government of Ontario has aimed to move toward a green energy economy, thus resulting in increased penetration of renewable energy sources as well as Plug-in hybrid electric vehicle (PHEV) technology. Penetration of renewable energy sources into microgrids are gradually being recognized as important alternatives in supply side planning. This thesis focuses on the optimal design, planning, sizing and operation of a hybrid, renewable energy based microgrid with the goal of minimizing the lifecycle cost, while taking into account environmental emissions. Four different configurations including a diesel-only, a fully renewable-based, a diesel-renewable mixed, and an external-grid connected microgrid are designed, to compare and evaluate their economics, operational performance and environmental emissions. Analysis is also carried out to determine the break-even economics for a grid-connected microgrid. The well-known energy modeling software for hybrid renewable energy systems, HOMER, is used in the studies reported in this thesis. An optimal power flow (OPF) based optimization framework considering two different objectives, minimizing feeder losses and PHEV charging cost, are presented to understand the impact of PHEV charging on distribution networks. Three different charging periods are considered and the impact of the Ontario Time-of-Use (TOU) tariff on PHEV charging schedules is examined. The impact of PHEV charging on distribution systems in the presence of renewable energy sources is discussed by extending the developed OPF based model to include the contribution of renewable energy sources. The proposed model is evaluated under a variety of scenarios.
4

The place of 0150 among manuscripts of Paul a collation and textual analysis /

Salai, Timothy P. January 2008 (has links)
Thesis (Th. M.)--Dallas Theological Seminary, 2008. / Includes bibliographical references (leaves [663]-667).
5

Codex 2464 background, collation, and textual analysis /

Todd, Billy R. January 2008 (has links)
Thesis (Th. M.)--Dallas Theological Seminary, 2008. / Includes bibliographical references (leaves [226]-230).
6

Codex 2464 background, collation, and textual analysis /

Todd, Billy R. January 2008 (has links)
Thesis (Th.M.)--Dallas Theological Seminary, 2008. / Description based on print version record. Includes bibliographical references (leaves [226]-230).
7

The place of 0150 among manuscripts of Paul a collation and textual analysis /

Salai, Timothy P. January 2008 (has links)
Thesis (Th.M.)--Dallas Theological Seminary, 2008. / Description based on print version record. Includes bibliographical references (leaves [663]-667).
8

Codex 2464 background, collation, and textual analysis /

Todd, Billy R. January 2008 (has links)
Thesis (Th. M.)--Dallas Theological Seminary, 2008. / Includes bibliographical references (leaves [226]-230).
9

The place of 0150 among manuscripts of Paul a collation and textual analysis /

Salai, Timothy P. January 2008 (has links)
Thesis (Th. M.)--Dallas Theological Seminary, 2008. / Includes bibliographical references (leaves [663]-667).
10

Effects of Large-Scale Penetration of Electric Vehicles on the Distribution Network and Mitigation by Demand Side Management

Oriaifo, Stacey I. 25 July 2014 (has links)
For the purpose of this study, data for low voltage distribution transformer loading in small communities in Maryland was collected from a local electric utility company. Specifically, analysis was done on three distribution transformers on their system. Each of these transformers serves at least one electric vehicle (EV) owner. Of the three transformers analyzed, Transformer 2 serves eight residential homes and has the highest risk of experiencing an overload if all customers purchase at least one EV. Transformer 2 has a nameplate rating of 25kVA (22.5kW assuming a 0.9 power factor). With one EV owner, Transformer 2 has a peak load of 46.82kW during the study period between August 4 and August 17, 2013. When seven additional EVs of different types were added in a simulated scenario, the peak load for Transformer 2 increased from 46.82kW to 89.76kW, which is outside the transformer thermal limit. With the implementation of TOU pricing, the peak load was reduced to 56.71kW from 89.76kW. By implementing a combination of TOU pricing and appliance cycling through demand side management (DSM), the peak load was further reduced to 52.27kW. / Master of Science

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