10,460 research outputs found
Community-Owned Solar Power and Micro Grids for New York State
This policy brief discusses how community owned solar projects and micro grids offer a sustainable alternative to reliance on the large power grid and polluting fossil fuels. It explains how micro grids work and looks at how they are connected to and can improve standard power grids or macro grids
Community-based micro grids: a common property resource problem
This paper introduces a new methodological and theoretical foundation for studying the reasons for successes and failures of community-based micro grids (CBMGs). While technical and financial factors involved are very critical they are comparatively well researched. This analysis argues that further research into, in particular, the institutional design of CBMGs is required in order to improve long-term sustainability. The paper suggests that the electricity in an isolated micro grid can be treated as a common property resource (CPR), which then opens up the established academic literature regarding collective action in the presence of CPRs. More specifically this paper analyses how the rich set of enabling conditions for collective action, which has been established in the context of traditional CPR situations such as water for irrigation or pasture for grazing, can be applied to the context of CBMGs. The goal is to arrive at workable recommendations for policy-makers and practitioners to inform the design and improve the long-term sustainability of CBMGs. Ultimately this has the potential to contribute towards efforts to bring modern energy services to significant parts of rural populations without electricity access
Power Talk in DC Micro Grids: Constellation Design and Error Probability Performance
Power talk is a novel concept for communication among units in a Micro Grid
(MG), where information is sent by using power electronics as modems and the
common bus of the MG as a communication medium. The technique is implemented by
modifying the droop control parameters from the primary control level. In this
paper, we consider power talk in a DC MG and introduce a channel model based on
Thevenin equivalent. The result is a channel whose state that can be estimated
by both the transmitter and the receiver. Using this model, we present design
of symbol constellations of arbitrary order and analyze the error probability
performance. Finally, we also show how to design adaptive modulation in the
proposed communication framework, which leads to significant performance
benefits.Comment: IEEE SmartGridComm 201
Precision Nitrogen Fertilization Technology with Micro Grids
Sensor-based precision fertilizer technologies are being developed and researched by production scientists. One such technology uses normalized difference vegetation index (NDVI) reflectance measurements of growing winter wheat plants and a nitrogen fertilizer optimization algorithm (NFOA) to determine nitrogen requirement necessary for plants to reach their yield plateau. A number of precision fertilizer application systems that use this technology are considered in this paper. A linear response stochastic plateau wheat yield function conditional on NDVI reflectance measurements is estimated and used within an expected profit-maximization framework to estimate upper bounds on the returns from the precision nitrogen application systems. The on-the-go precision system that assumes perfect information was approximately $7 per acre more profitable than the convention of applying 80 pounds of nitrogen prior to planting in the fall. The whole-field precision system was break-even with conventional methods.Research and Development/Tech Change/Emerging Technologies,
An adaptive disturbance rejection control scheme for voltage regulation in DC micro-grids
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Uncertain generation by renewable sources and load variations have resulted in adding energy storage systems in the grid to maintain grid parameters (voltage, frequency) within prescribed limits. The disturbances being non-deterministic in nature, the voltage regulation control by the storage systems relies mostly on dual loop architecture with an outer voltage and inner current loop. Improvement in controller dynamics can be achieved through feed forward of disturbance profile but at expense of additional sensors and communication in the grid. This work explores the application of an adaptive disturbance rejection control scheme for disturbance estimation (without using additional sensors) employing an extended state and proportional integral observer (PI+ESO). The proposed observer aim to achieve robust disturbance estimation under grid parameter uncertainty. The effectiveness of the proposed scheme over the conventional one will be put forward through H8 and H2 norm analysis of the system. The design and simulation results of the proposed scheme will be presented in this work.Peer ReviewedPostprint (author's final draft
Joint Optimal Pricing and Electrical Efficiency Enforcement for Rational Agents in Micro Grids
In electrical distribution grids, the constantly increasing number of power
generation devices based on renewables demands a transition from a centralized
to a distributed generation paradigm. In fact, power injection from Distributed
Energy Resources (DERs) can be selectively controlled to achieve other
objectives beyond supporting loads, such as the minimization of the power
losses along the distribution lines and the subsequent increase of the grid
hosting capacity. However, these technical achievements are only possible if
alongside electrical optimization schemes, a suitable market model is set up to
promote cooperation from the end users. In contrast with the existing
literature, where energy trading and electrical optimization of the grid are
often treated separately or the trading strategy is tailored to a specific
electrical optimization objective, in this work we consider their joint
optimization. Specifically, we present a multi-objective optimization problem
accounting for energy trading, where: 1) DERs try to maximize their profit,
resulting from selling their surplus energy, 2) the loads try to minimize their
expense, and 3) the main power supplier aims at maximizing the electrical grid
efficiency through a suitable discount policy. This optimization problem is
proved to be non convex, and an equivalent convex formulation is derived.
Centralized solutions are discussed first, and are subsequently distributed.
Numerical results to demonstrate the effectiveness of the so obtained optimal
policies are then presented
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