scholarly journals Automatic Coordination of Internet-Connected Thermostats for Power Balancing and Frequency Control in Smart Microgrids

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1936 ◽  
Author(s):  
Saeid Bashash ◽  
Kai Lun Lee
Keyword(s):  
Frequency Control ◽  
Supply And Demand ◽  
Peak Load ◽  
Weather Conditions ◽  
Frequency Measurement ◽  
Power Generators ◽  
Generation Cost ◽  
Generation Capacity ◽  
Feedback Control Strategy ◽  
The Individual

This paper proposes a novel feedback control strategy, so-called clock-like controller (CLC), to balance power supply and demand in smart microgrids by adjusting the setpoint temperatures of air conditioning (AC) loads. In the CLC algorithm, the grid operator communicates with the individual thermostats via the Internet and adjusts their setpoints by discrete temperature intervals (e.g., ±0.5 °C). Numerical simulations indicate that the proposed algorithm is able to deliver a smooth controllability of the aggregate AC power despite discrete temperature offsets. It can also be used for peak load shedding to mitigate the power generation cost. The CLC algorithm is then integrated into the grid frequency control problem, in which both power generators and loads in the network attempt to regulate the frequency of the system despite disturbances from demand, renewable sources, and local weather conditions. An autonomous microgrid model including a steam and a hydro generator, a solar energy source, and a large number of thermostatic loads is developed to evaluate and demonstrate the proposed method. Simulation results indicate that the AC loads with CLC algorithm can help maintain the power system frequency during extreme events when demand exceeds the maximum generation capacity available to the network. Under normal conditions, the contribution of demand-side control is marginalized by the fast responding generators, because of time delays in the frequency measurement and internet communication network.

scholarly journals Price Based Demand Response for Optimal Frequency Stabilization in ORC Solar Thermal Based Isolated Hybrid Microgrid under Salp Swarm Technique

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2209
Author(s):  
Abdul Latif ◽  
Manidipa Paul ◽  
Dulal Chandra Das ◽  
S. M. Suhail Hussain ◽  
Taha Selim Ustun
Keyword(s):  
Demand Response ◽  
Frequency Control ◽  
Thermal Power ◽  
Peak Load ◽  
Energy System ◽  
Frequency Stabilization ◽  
Load Frequency Control ◽  
Solar Thermal ◽  
Proportional Integral ◽  
Hybrid Microgrid

Smart grid technology enables active participation of the consumers to reschedule their energy consumption through demand response (DR). The price-based program in demand response indirectly induces consumers to dynamically vary their energy use patterns following different electricity prices. In this paper, a real-time price (RTP)-based demand response scheme is proposed for thermostatically controllable loads (TCLs) that contribute to a large portion of residential loads, such as air conditioners, refrigerators and heaters. Wind turbine generator (WTG) systems, solar thermal power systems (STPSs), diesel engine generators (DEGs), fuel cells (FCs) and aqua electrolyzers (AEs) are employed in a hybrid microgrid system to investigate the contribution of price-based demand response (PBDR) in frequency control. Simulation results show that the load frequency control scheme with dynamic PBDR improves the system’s stability and encourages economic operation of the system at both the consumer and generation level. Performance comparison of the genetic algorithm (GA) and salp swarm algorithm (SSA)-based controllers (proportional-integral (PI) or proportional integral derivative (PID)) is performed, and the hybrid energy system model with demand response shows the supremacy of SSA in terms of minimization of peak load and enhanced frequency stabilization of the system.

scholarly journals Ensemble-Based Storm Surge Forecasting Models

2017 ◽  
Vol 32 (5) ◽  
pp. 1921-1936 ◽  
Author(s):  
Amin Salighehdar ◽  
Ziwen Ye ◽  
Mingzhe Liu ◽  
Ionut Florescu ◽  
Alan F. Blumberg
Keyword(s):  
New York ◽  
Storm Surge ◽  
Weather Conditions ◽  
Difficult Problem ◽  
Forecasting Models ◽  
Bay Area ◽  
Temperature Levels ◽  
The Individual ◽  
Specific Sense ◽  
Stated Purpose

Abstract Accurate prediction of storm surge is a difficult problem. Most forecast systems produce multiple possible forecasts depending on the variability in weather conditions, possible temperature levels, winds, etc. Ensemble modeling techniques have been developed with the stated purpose of obtaining the best forecast (in some specific sense) from the individual forecasts. In this work a statistical methodology of evaluating the performance of multiple ensemble forecasting models is developed. The methodology is applied to predicting storm surge in the New York Harbor area. Data from three hurricane events collected from multiple locations in the New York Bay area are used. The methodology produces three key findings for the particular test data used. First, it is found that even the simplest possible way of creating an ensemble produces results superior to those of any single forecast. Second, for the data used and the events under study the methodology did not interact with any event at any location studied. Third, based on the methodology results for the data studied selecting the best-performing ensemble models for each specific location may be possible.

An equilibrium displacement approach to analyzing the effects of tariff reduction on farmers’ profits

2016 ◽  
Vol 20 (4) ◽  
pp. 349-363 ◽  
Author(s):  
Byeong-Il Ahn ◽  
Jeong-Bin Im
Keyword(s):  
Cost Function ◽  
Supply And Demand ◽  
Differential Forms ◽  
Trade Agreement ◽  
Tariff Reduction ◽  
Content Type ◽  
Equilibrium Displacement ◽  
Demand Equations ◽  
The Individual ◽  
The Cost

Purpose The purpose of this paper is to develop an equilibrium displacement model (EDM) that is able to evaluate the impacts of a free trade agreement (FTA) on the profits of farmers. Empirical applications of the developed EDM are performed for evaluating the influences of Korea-Chile FTA on the grape industry in Korea. Design/methodology/approach Supply and demand equations together with profit function of individual farmers are converted into log-differential forms that compose the EDM. The cost function of grape producers is estimated for deriving the parameters that are required in applying the developed EDM. Findings The share of profit within revenue and the elasticity of cost with respect to quantity in the cost function play key roles in assessing the change in farmers’ profit. The empirical assessment of the effects of Korea-Chile FTA indicates that this FTA has little impact on the Korean grape market and grape producers in Korea. Originality/value Usefulness of the existing EDM has been limited in evaluating the impacts of exogenous shocks on the individual farmer level. This paper fills this gap by developing an EDM that assesses the impacts of tariff reduction on farm-level profit.

scholarly journals Flight Simulator’s Energy Consumption Depending on the Conditions of the Air Operation

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 580
Author(s):  
Michał Gołębiewski ◽  
Marta Galant-Gołębiewska ◽  
Remigiusz Jasiński
Keyword(s):  
Energy Consumption ◽  
Natural Environment ◽  
Negative Impact ◽  
Weather Conditions ◽  
Civil Aviation ◽  
Flight Simulator ◽  
Motion Platform ◽  
Simulator Motion ◽  
The Individual ◽  
The Impact

Protection of the natural environment is a key activity driving development in the transport discipline today. The use of simulators to train civil aviation pilots provides an excellent opportunity to maintain the balance between efficiency and limit the negative impact of transport on the environment. Therefore, we decided to determine the impact of selected simulations of air operations on energy consumption. The aim of the research was to determine the energy consumption of the flight simulator depending on the type of flight operation and configuration used. We also decided to compare the obtained result with the energy consumption of an aircraft of a similar class, performing a similar aviation operation and other means of transport. In order to obtain the results, a research plan was proposed consisting of 12 scenarios differing in the simulated aircraft model, weather conditions and the use of the simulator motion platform. In each of the scenarios, energy consumption was measured, taking into account the individual components of the simulator. The research showed that the use of a flight simulator has a much smaller negative impact on the natural environment than flying in a traditional plane. Use of a motion platform indicated a change in energy consumption of approximately 40% (in general, flight simulator configuration can change energy consumption by up to 50%). The deterioration of weather conditions during the simulation caused an increase in energy consumption of 14% when motion was disabled and 18% when motion was enabled. Energy consumption in the initial stages of pilot training can be reduced by 97% by using flight simulators compared to aircraft training.

scholarly journals A MODEL OF MANAGING THE URBAN MOBILITY PLANNING PROCESS / MODEL UPRAVLJANJA PROCESOM PLANIRANJA URBANE MOBILNOSTI

2019 ◽  
Vol 16 (2) ◽  
Author(s):  
Mustafa Mehanović ◽  
Nermin Palić
Keyword(s):  
Process Model ◽  
Planning Process ◽  
Supply And Demand ◽  
Urban Mobility ◽  
Research Results ◽  
Traffic System ◽  
Development Plans ◽  
Sustainable Urban Mobility ◽  
The Individual ◽  
The City

The subject of research in this paper is the planning of urban mobility development in the narrow part of Sarajevo using a model based on the growth matrix. The hypothesis of this research is: Based on the analysis of supply and demand of the city traffic system, good practices in sustainable urban mobility and existing strategies and development plans, a model for managing the whole planning process of sustainable urban mobility of the city traffic system in Sarajevo by 2026 can be proposed.In accordance with the experience of Europe’s main urban mobility observatory (Eltis) and sustainable urban mobility plans (SUMPs), the key elements are defined. The next step, after defining the elements of urban mobility, is to carry out the quantification of elements for 2016. Thereafter, there is a concise explanation of the growth matrix and model of managing the urban mobility planning process is created. In the research results, direct and indirect growth rates were elaborated and analyzed, i.e. the individual and synergic effects of the model. Finally, the synthesis of the research results was presented.

scholarly journals La Educación en Colombia: Arquetipo de Correspondencia con la Economía Global y de Mercado / Education in Colombia: Archetype Correspondence with the Global Economy and Market

2015 ◽  
Vol 6 (1) ◽  
pp. 161
Author(s):  
Luis Manuel Marrugo Fruto
Keyword(s):  
Labor Market ◽  
Educational System ◽  
Global Economy ◽  
Supply And Demand ◽  
First Century ◽  
Late Nineteenth Century ◽  
Early Twenty ◽  
El Sistema ◽  
Siglo Xix ◽  
The Individual

Se busca dilucidar los principales hitos históricos de la educación colombiana en relación con las políticas de la economía global y de mercado, entre finales del siglo XIX e inicios del siglo XXI. Se mostrarán limitaciones y problemáticas heredadas por el sistema educativo en su propósito de funcionar como empresa, bajo las leyes de oferta y demanda, es decir, un sistema educativo con la convicción de formar un perfil de individuo y de sociedad como mano de obra, dócil, obediente y con competencias de calidad para el mercado laboral de lossistema – mundo postmodernos, en desmedro de una educación humanizada.Metodológicamente es producto de una revisión de tema. Como principal resultado se muestra la tendencia desde los inicios de la educación colombiana a corresponderse con el mercado laboral. Abstract.It seeks to elucidate the main historical landmarks of Colombian education in relation to the policies of the global economy and market, between the late nineteenth century and early twenty-first century.  Limitations and problems inherited by the educational system in order to operate as a company under the laws of supply and demand, a docile educational system with the conviction of forming a profile of the individual and society as labor, are displayed obediently and quality skills for the labor market system - postmodern world, at the expenses of a humanized education. Methodologically is the result of a review of subject. The main result shows the trend since the beginning of Colombian education to match the labor market.

scholarly journals Optimization Technique Inspired Load Frequency Controller for Multi Area Power System with Renewable Energy Source

2021 ◽  
Vol 850 (1) ◽  
pp. 012017
Author(s):  
J Shri Saranyaa ◽  
A Peer Fathima ◽  
Asutosh Mishra ◽  
Rushali Ghosh ◽  
Shalmali Das
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Control Method ◽  
Frequency Control ◽  
Renewable Energy Sources ◽  
Optimization Technique ◽  
Optimization Method ◽  
Load Frequency Control ◽  
Load Frequency ◽  
The Individual

Abstract Modern day scenario has an increasing power demand due to the growing development which indeed increases the load on the generation which might cause turbulence in the system and may bounce out of stability. The governor itself can’t handle such frequent load changes and adjust the generation amount to keep the frequency between the margins. This paper proposes an approach towards such predicament to incorporate an optimization method in order to ensure stability of the system despite the drastic changes in demand. Load frequency control is a control method for maintaining the frequency of the system during the change in demand. Use of controllers has proven to be effective in controlling the frequency deviations in the power systems and the response of the controller is further improved using optimization technique for better stability. The PID controller tuned by Particle Swarm Optimization is employed in multi-area system which reduces the time response by a considerable amount and the deviation settles much quicker despite the rapid load changes. The proposed controller is executed further for renewable energy sources connected to the individual areas and demonstration proves that the optimized controller is efficient enough in handling the frequency deviations when wind and solar with sunlight penetration is incorporated.

A Decentralized Load Frequency Control Method by Means of Frequency Measurement of Adjacent Power Systems

1988 ◽  
Vol 21 (11) ◽  
pp. 387-393 ◽  
Author(s):  
H. Sasaki ◽  
H. Yorino ◽  
T. Suizu ◽  
S. Yurino ◽  
R. Yokoyama ◽  
...  
Keyword(s):  
Power Systems ◽  
Control Method ◽  
Frequency Control ◽  
Frequency Measurement ◽  
Load Frequency Control ◽  
Load Frequency

scholarly journals Hybrid Wind–PV Frequency Control Strategy under Variable Weather Conditions in Isolated Power Systems

2020 ◽  
Vol 12 (18) ◽  
pp. 7750 ◽  
Author(s):  
Ana Fernández-Guillamón ◽  
Guillermo Martínez-Lucas ◽  
Ángel Molina-García ◽  
Jose-Ignacio Sarasua
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Control Strategy ◽  
Rotational Speed ◽  
Power Plants ◽  
Mean Squared Error ◽  
Frequency Control ◽  
Weather Conditions ◽  
Squared Error ◽  
Variable Weather

Over the last two decades, variable renewable energy technologies (i.e., variable-speed wind turbines (VSWTs) and photovoltaic (PV) power plants) have gradually replaced conventional generation units. However, these renewable generators are connected to the grid through power converters decoupled from the grid and do not provide any rotational inertia, subsequently decreasing the overall power system’s inertia. Moreover, the variable and stochastic nature of wind speed and solar irradiation may lead to large frequency deviations, especially in isolated power systems. This paper proposes a hybrid wind–PV frequency control strategy for isolated power systems with high renewable energy source integration under variable weather conditions. A new PV controller monitoring the VSWTs’ rotational speed deviation is presented in order to modify the PV-generated power accordingly and improve the rotational speed deviations of VSWTs. The power systems modeled include thermal, hydro-power, VSWT, and PV power plants, with generation mixes in line with future European scenarios. The hybrid wind–PV strategy is compared to three other frequency strategies already presented in the specific literature, and gets better results in terms of frequency deviation (reducing the mean squared error between 20% and 95%). Additionally, the rotational speed deviation of VSWTs is also reduced with the proposed approach, providing the same mean squared error as the case in which VSWTs do not participate in frequency control. However, this hybrid strategy requires up to a 30% reduction in the PV-generated energy. Extensive detailing of results and discussion can be also found in the paper.

In Situ Identification of Natural Frequency Branches in Gyroscopic Systems via Autoresonance and Phase-Locked Loop

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Solomon Davis ◽  
Shachar Tresser ◽  
Netanel Ariel ◽  
Alex Ferdinskoif ◽  
Izhak Bucher
Keyword(s):  
Rotation Speed ◽  
Frequency Control ◽  
Phase Locked Loop ◽  
Campbell Diagram ◽  
Modal Frequency ◽  
At Resonance ◽  
Bending Mode ◽  
Run Up ◽  
Feedback Algorithm ◽  
The Individual

Abstract The methods described allow one to directly measure the individual branches of the Campbell diagram of a physical gyroscopic system at any rotation speed. Typically, such data are acquired by exciting the vibration modes through naturally occurring unbalance forces. During run-up, these forces expose some of the Campbell diagram, but mainly the forward whirling branches, leaving the backward whirling branches mostly hidden. Furthermore, good modal frequency data are only acquired at critical speeds. The methods proposed here allow one to excite either a forward or backward whirling mode at any rotation speed in a precisely controlled manner, greatly improving the quality of an acquired Campbell diagram. The technique employs an external excitation device that automatically produces oscillating forces at a chosen modal frequency. Control is based on the autoresonance feedback algorithm, which can excite a mechanical system at resonance effectively. It will also be shown that with two actuators and two sensors, one can choose which bending mode to excite at resonance in either the forward or backward whirling direction. As the rotation speed is then gradually increased, one can measure the speed dependence of the resonance frequency. Furthermore, when combining autoresonance with a phase-locked loop, one can acquire very clean measurements by removing most of the noise generated by the unbalance and other sources. The technique is demonstrated analytically, numerically, and experimentally.

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