579 resultados para demand response

em Queensland University of Technology - ePrints Archive


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Price based technique is one way to handle increase in peak demand and deal with voltage violations in residential distribution systems. This paper proposes an improved real time pricing scheme for residential customers with demand response option. Smart meters and in-home display units are used to broadcast the price and appropriate load adjustment signals. Customers are given an opportunity to respond to the signals and adjust the loads. This scheme helps distribution companies to deal with overloading problems and voltage issues in a more efficient way. Also, variations in wholesale electricity prices are passed on to electricity customers to take collective measure to reduce network peak demand. It is ensured that both customers and utility are benefitted by this scheme.

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This paper proposes a reward based demand response algorithm for residential customers to shave network peaks. Customer survey information is used to calculate various criteria indices reflecting their priority and flexibility. Criteria indices and sensitivity based house ranking is used for appropriate load selection in the feeder for demand response. Customer Rewards (CR) are paid based on load shift and voltage improvement due to load adjustment. The proposed algorithm can be deployed in residential distribution networks using a two-level hierarchical control scheme. Realistic residential load model consisting of non-controllable and controllable appliances is considered in this study. The effectiveness of the proposed demand response scheme on the annual load growth of the feeder is also investigated. Simulation results show that reduced peak demand, improved network voltage performance, and customer satisfaction can be achieved.

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This thesis introduces advanced Demand Response algorithms for residential appliances to provide benefits for both utility and customers. The algorithms are engaged in scheduling appliances appropriately in a critical peak day to alleviate network peak, adverse voltage conditions and wholesale price spikes also reducing the cost of residential energy consumption. Initially, a demand response technique via customer reward is proposed, where the utility controls appliances to achieve network improvement. Then, an improved real-time pricing scheme is introduced and customers are supported by energy management schedulers to actively participate in it. Finally, the demand response algorithm is improved to provide frequency regulation services.

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With the rapid development of various technologies and applications in smart grid implementation, demand response has attracted growing research interests because of its potentials in enhancing power grid reliability with reduced system operation costs. This paper presents a new demand response model with elastic economic dispatch in a locational marginal pricing market. It models system economic dispatch as a feedback control process, and introduces a flexible and adjustable load cost as a controlled signal to adjust demand response. Compared with the conventional “one time use” static load dispatch model, this dynamic feedback demand response model may adjust the load to a desired level in a finite number of time steps and a proof of convergence is provided. In addition, Monte Carlo simulation and boundary calculation using interval mathematics are applied for describing uncertainty of end-user's response to an independent system operator's expected dispatch. A numerical analysis based on the modified Pennsylvania-Jersey-Maryland power pool five-bus system is introduced for simulation and the results verify the effectiveness of the proposed model. System operators may use the proposed model to obtain insights in demand response processes for their decision-making regarding system load levels and operation conditions.

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Demand response can be used for providing regulation services in the electricity markets. The retailers can bid in a day-ahead market and respond to real-time regulation signal by load control. This paper proposes a new stochastic ranking method to provide regulation services via demand response. A pool of thermostatically controllable appliances (TCAs) such as air conditioners and water heaters are adjusted using direct load control method. The selection of appliances is based on a probabilistic ranking technique utilizing attributes such as temperature variation and statuses of TCAs. These attributes are stochastically forecasted for the next time step using day-ahead information. System performance is analyzed with a sample regulation signal. Network capability to provide regulation services under various seasons is analyzed. The effect of network size on the regulation services is also investigated.

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The aim of this work is to develop a Demand-Side-Response (DSR) model, which assists electricity end-users to be engaged in mitigating peak demands on the electricity network in Eastern and Southern Australia. The proposed innovative model will comprise a technical set-up of a programmable internet relay, a router, solid state switches in addition to the suitable software to control electricity demand at user's premises. The software on appropriate multimedia tool (CD Rom) will be curtailing/shifting electric loads to the most appropriate time of the day following the implemented economic model, which is designed to be maximizing financial benefits to electricity consumers. Additionally the model is targeting a national electrical load be spread-out evenly throughout the year in order to satisfy best economic performance for electricity generation, transmission and distribution. The model is applicable in region managed by the Australian Energy Management Operator (AEMO) covering states of Eastern-, Southern-Australia and Tasmania.

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The paper presents a demand side response scheme,which assists electricity consumers to proactively control own demands in such a way to deliberately avert congestion periods on the electrical network. The scheme allows shifting loads from peak to low demand periods in an attempt to flattening the national electricity requirement. The scheme can be concurrently used to accommodate the utilization of renewable energy sources,that might be available at user’s premises. In addition the scheme allows a full-capacity utilization of the available electrical infrastructure by organizing a wide-use of electric vehicles. The scheme is applicable in the Eastern and Southern States of Australia managed by the Australian Energy Market Operator. The results indicate the potential of the scheme to achieve energy savings and release capacity to accommodate renewable energy and electrical vehicle technologies.

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Depleting fossil fuel resources and increased accumulation of greenhouse gas emissions are increasingly making electrical vehicles (EV) attractive option for the transportation sector. However uncontrolled random charging and discharging of EVs may aggravate the problems of an already stressed system during the peak demand and cause voltage problems during low demand. This paper develops a demand side response scheme for properly integrating EVs in the Electrical Network. The scheme enacted upon information on electricity market conditions regularly released by the Australian Energy Market Operator (AEMO) on the internet. The scheme adopts Internet relays and solid state switches to cycle charging and discharging of EVs. Due to the pending time-of-use and real-price programs, financial benefits will represent driving incentives to consumers to implement the scheme. A wide-scale dissemination of the scheme is expected to mitigate excessive peaks on the electrical network with all associated technical, economic and social benefits.

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The growing demand of air-conditioning is one of the largest contributors to Australia’s overall electricity consumption. This has started to create peak load supply problems for some electricity utilities particularly in Queensland. This research aimed to develop consumer demand side response model to assist electricity consumers to mitigate peak demand on the electrical network. The model developed demand side response model to allow consumers to manage and control air conditioning for every period, it is called intelligent control. This research investigates optimal response of end-user toward electricity price for several cases in the near future, such as: no spike, spike and probability spike price cases. The results indicate the potential of the scheme to achieve energy savings, reducing electricity bills (costs) to the consumer and targeting best economic performance for electrical generation distribution and transmission.

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The aims of this project is to develop demand side response model which assists electricity consumers who are exposed to the market price through aggregator to manage the air-conditioning peak electricity demand. The main contribution of this research is to show how consumers can optimise the energy cost caused by the air-conditioning load considering the electricity market price and network overload. The model is tested with selected characteristics of the room, Queensland electricity market data from Australian Energy Market Operator and data from the Bureau of Statistics on temperatures in Brisbane, during weekdays on hot days from 2011 - 2012.

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The aim of this work is to develop a demand-side-response model, which assists electricity consumers exposed to the market price to independently and proactively manage air-conditioning peak electricity demand. The main contribution of this research is to show how consumers can optimize the energy cost caused by the air conditioning load considering to several cases e.g. normal price, spike price, and the probability of a price spike case. This model also investigated how air-conditioning applies a pre-cooling method when there is a substantial risk of a price spike. The results indicate the potential of the scheme to achieve financial benefits for consumers and target the best economic performance for electrical generation distribution and transmission. The model was tested with Queensland electricity market data from the Australian Energy Market Operator and Brisbane temperature data from the Bureau of Statistics regarding hot days from 2011 to 2012.

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The lack of inclusive housing in Australia contributes to the marginalization and exclusion of people with disability and older people from family and community life. The Australian government has handed over the responsibility of increasing the supply of inclusive housing to the housing industry through an agreed national access standard and a voluntary strategy. Voluntary strategies have not been successful in other constituencies and little is known about what would work in Australia today. Findings from a research project into the voluntariness of the housing industry indicate that a reliable and consistent supply is unlikely without an equivalent increase in demand. The strategy has, however, an important role to play in the task of changing housing industry practices towards building more inclusive communities.

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This thesis examined the impact of previous hamstring injury and fatigue on the function of the hamstring muscles and their neural control. The work established the role of neuromuscular inhibition after hamstring injury and involved the development of a new field testing device for eccentric hamstring strength, which is now in high demand in elite sport worldwide. David has four peer-reviewed publications from this doctoral work.

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Executive Summary Emergency health is a critical component of Australia’s health system and emergency departments (EDs) are increasingly congested from growing demand and blocked access to inpatient beds. The Emergency Health Services Queensland (EHSQ) study aims to identify the factors driving increased demand for emergency health and to evaluate strategies which may safely reduce the future demand growth. This monograph addresses the perspectives of users of both ambulance services and EDs. The research reported here aimed to identify the perspectives of users of emergency health services, both ambulance services and public hospital Emergency Departments and to identify the factors that they took into consideration when exercising their choice of location for acute health care. A cross-sectional survey design was used involving a survey of patients or their carers presenting to the EDs of a stratified sample of eight hospitals. A specific purpose questionnaire was developed based on a novel theoretical model which had been derived from analysis of the literature (Monograph 1). Two survey versions were developed: one for adult patients (self-complete); and one for children (to be completed by parents/guardians). The questionnaires measured perceptions of social support, health status, illness severity, self-efficacy; beliefs and attitudes towards ED and ambulance services; reasons for using these services, and actions taken prior to the service request. The survey was conducted at a stratified sample of eight hospitals representing major cities (four), inner regional (two) and outer regional and remote (two). Due to practical limitations, data were collected for ambulance and ED users within hospital EDs, while patients were waiting for or under treatment. A sample size quota was determined for each ED based on their 2009/10 presentation volumes. The data collection was conducted by four members of the research team and a group of eight interviewers between March and May 2011 (corresponding to autumn season). Of the total of 1608 patients in all eight emergency departments the interviewers were able to approach 1361 (85%) patients and seek their consent to participate in the study. In total, 911 valid surveys were available for analysis (response rate= 67%). These studies demonstrate that patients elected to attend hospital EDs in a considered fashion after weighing up alternatives and there is no evidence of deliberate or ill-informed misuse. • Patients attending ED have high levels of social support and self-efficacy that speak to the considered and purposeful nature of the exercise of choice. • About one third of patients have new conditions while two thirds have chronic illnesses • More than half the attendees (53.1%) had consulted a healthcare professional prior to making the decision. • The decision to seek urgent care at an ED was mostly constructed around the patient’s perception of the urgency and severity of their illness, reinforced by a strong perception that the hospital ED was the correct location for them (better specialised staff, better care for my condition, other options not as suitable). • 33% of the respondent held private hospital insurance but nevertheless attended a public hospital ED. Similarly patients exercised considered and rational judgements in their choice to seek help from the ambulance service. • The decision to call for ambulance assistance was based on a strong perception about the severity of the illness (too severe to use other means of transport) and that other options were not considered appropriate. • The decision also appeared influenced by a perception that the ambulance provided appropriate access to the ED which was considered most appropriate for their particular condition (too severe to go elsewhere, all facilities in one spot, better specialised and better care). • In 43.8% of cases a health care professional advised use of the ambulance. • Only a small number of people perceived that ambulance should be freely available regardless of severity or appropriateness. These findings confirm a growing understanding that the choice of professional emergency health care services is not made lightly but rather made by reasonable people exercising a judgement which is influenced by public awareness of the risks of acute health and which is most often informed by health professionals. It is also made on the basis of a rational weighing up of alternatives and a deliberate and considered choice to seek assistance from a service which the patient perceived was most appropriate to their needs at that time. These findings add weight to dispensing with public perceptions that ED and ambulance congestion is a result of inappropriate choice by patients. The challenge for health services is to better understand the patient’s needs and to design and validate services that meet those needs. The failure of our health system to do so should not be grounds for blaming the patient, claiming inappropriate patient choices.

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The endoplasmic reticulum (ER) is the central organelle in the eukaryotic secretory pathway. The ER functions in protein synthesis and maturation and is crucial for proper maintenance of cellular homeostasis and adaptation to adverse environments. Acting as a cellular sentinel, the ER is exquisitely sensitive to changing environments principally via the ER quality control machinery. When perturbed, ER-stress triggers a tightly regulated and highly conserved, signal transduction pathway known as the unfolded protein response (UPR) that prevents the dangerous accumulation of unfolded/misfolded proteins. In situations where excessive UPR activity surpasses threshold levels, cells deteriorate and eventually trigger programmed cell death (PCD) as a way for the organism to cope with dysfunctional or toxic signals. The programmed cell death that results from excessive ER stress in mammalian systems contributes to several important diseases including hypoxia, neurodegeneration, and diabetes. Importantly, hallmark features and markers of cell death that are associated with ER stress in mammals are also found in plants. In particular, there is a common, conserved set of chaperones that modulate ER cell death signaling. Here we review the elements of plant cell death responses to ER stress and note that an increasing number of plant-pathogen interactions are being identified in which the host ER is targeted by plant pathogens to establish compatibility.