controlled by the micro grid aggregator which is treated as a nonprofit agent. In these studies, the objective was either to minimize the operating costs of the entire micro grid or to maintain a balance between the demand and local generation.
To the best of our knowledge, the variability and uncertainty impacts of excessive renewable energy generation on the unit commitment decisions and real-time dispatch of a micro grid with controllable DGs in the presence of ESS, demand response (DR) and interruption loads have not been investigated before. Thus, this paper examines probabilistic coordination of DERs on micro grid operation considering the associated uncertainties and hourly interruptible loads for a variety of customers. The work presented in this paper can be summarized as follows:
(1) A comprehensive stochastic mathematical model has been developed to enable operation interactions of DERs under uncertainty in an islanded micro grid in order to mitigate the variability and intermittency associated with large-scale integration of renewable energy generation.
(2) The coordinated influence of DERs on micro grids’ operation has been examined with respect to their independent presence and with consideration of the stochastic operational framework.
(3) The hourly interruption costfor a variety of customers has been incorporated as a means to determine the optimal probabilistic load interruption, if required. The effects of probabilistic coordination of DERs on load
So, the above issues can be applied to distributed power systems similarly, and the recent research focuses are summarized as follows:
For the purpose of this discussion, the specifics of the electrical energy system in the United States are not important, rather an introduction to the basic elements of the system, who they serve, how they relate the larger whole and how they are regulated will suffice. On a most basic level the electrical grid, or system, in the United States is comprised of three basic components; the generation of electrical energy, transmission of this energy, and the distribution of this energy to end consumers.
The United States has an extremely well developed and maintained power grid which in its current state is configured primarily for non-renewable power generation. As the cost of green power comes down there will be an increasing amount of green power generation on the grid. This new, cleaner source of energy unfortunately has disadvantages that more traditional methods of power generation don’t suffer from, namely consistently. Photo-voltaic cells will only work when the sun is shining and wind turbines only spin when wind is present. I will be examining the readiness for renewable power of the power grid within the United States as well as investigating improvements that would allow for a larger national power generation percentage of renewable
Moreover, DER may have negative impacts for traditional utilities that are unable to adapt to these new energy systems, which may even develop over time into a utility “death spiral” concern. The confluence of technological developments in renewable energy production and distributed computing power has caused a shift in the industry from more one-way, command & control systems to more reliable, customer driven, and energy-efficient systems.
This condition imposes unique challenges on the planning and operation of a hydro-wind integrated power system in a reliable manner [8]. Previous studies on wind penetration issues and solutions found that the limiting factors of wind integration include penetration level, forecasting reliability, geographic diversity, hydro generation flexibility and control of the overall system [6]. Control is a key enabling factor for the deployment of renewable energy systems [9]. Control techniques such as linear and dynamic programming, genetic algorithms, and neural networks, proposed by past research, for the control and economic dispatch of renewable energy systems, have not been acknowledged to be error free [3]. Two major flaws identified in existing techniques include the lack of ease-of-use, and adaptability to new situations and evolving regulations [3]. These flaws pose major operational challenges to utilities and thus, make control technologies optimization an imperative research endeavor.
During the time of the project, Energy costs are steadily rising and were predicted to continue this trend going into the future. At the same time, utility companies were beginning to implement Smart Grid technologies to increase the efficiency of energy distribution. One resulting program to emerge from these new technologies was Demand and Response contracting. (Emblemsvåg and Bras, 2000). This program allowed customers to obtain a discount on their utility costs in return for reducing their energy usage during specified times. If a company is able to understand their processes well enough to change and meet the energy levels
According to the case study written by Jurek, Bras, Guldberg, D’Arcy, Oh, and Biller, energy costs were steadily rising and were predicted to continue this trend going into the future. At the same time, utility companies were beginning to implement Smart Grid technologies to increase the efficiency of energy distribution. One resulting program to emerge from these new technologies was Demand and Response contracting. (Jurek, Bras, Guldberg, D’Arcy, Oh, Biller 2000). This program allowed customers to obtain a discount on their
The aim of this paper is to replace traditional components like diesel generators which are used to generate power in a microgrid with renewable energy sources for an Air-force field deployable hospital (AFFDH). In this paper we assume that Air-force field deployable hospital consumes approximately 70KVA of peak power. ETAP software is used to operate for island and grid connected mode and also load flow and short circuit analysis are performed on the system for variety of load and fault scenarios.
Microgeneration addresses some of the fundamental problems with the centralised system that we presently use to generate power, and some commentators (Greenpeace, 2006; Greenpeace, 2005) have claimed that distributed generation should be the basis of any low-carbon economy. This view was shared by many environmental activists and government bodies however uptake has not matched the initial enthusiasm.
A microgrid is an interconnection of distributed generations (DGs), either a set of dispatchable generating sources such as, gas turbines and fuel cells or non-dispatchable generators such as, wind turbines and photovoltaic sources, integrated with electrical and thermal energy storage devices to meet the customers’ local energy needs, operating as a single system and small-scale, on low-voltage distribution systems providing both power and heat. To ensure that the microgrid is operated as a single aggregated system and meets power quality, reliability and security standards, power electronic interfaces and controls need to be applied [1-2].
in [3], developed performance characterizations in terms of the outage events and the associated outage probabilities.
systems. In particular, my research interests are shaped by the emerging trend towards new power grids and energy structures. In the past several years, centralized power systems are replaced by distributed power grids and the penetration level of renewable energy keep increasing in the traditional market. My research will mainly focus on the challenges to which electricity operators would face, especially in case of the uncertainty of
Abstract: This paper presents stochastic synchronization of distributed energy resources (DERs) operation in an islanded micro grid in light of uncertainties. In doing so, a comprehensive stochastic mathematical model is developed which incorporates a set of valid probable scenarios for the uncertainties of load and irregularity in wind and solar generation sources. The uncertainty is addressed through a combination of a stochastic optimization model and additional reserve requirements. The model also includes hourly interruption costs for a variety of customer types as a means of determining the optimal stochastic interruptible load whose reliability-based value is very low to enable it to be shed if necessary. A study is carried out using a benchmark micro grid; numerical results demonstrate that coordinated operation of DERs brings prominent benefits in terms of expected operation costs and system security. This stochastic
In order to identify one major issue in smart grids design, we propose a thought experiment:
The smart grid uses technology to self locate faults so their rectification is fast and sound. This self healing property of smart grid makes it more reliable than the conventional grid. Main technology used here is state estimation. Multiple routes are used in a smart grid which were used in the old grid as well. But mostly they were radial in nature so that any failure can cause total failure of the system and the current would be shunted to other elements.