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Economic Dispatch
The merit order is a way of ranking available sources of energy, especially electrical generation, based on ascending order of price (which may reflect the order of their short-run marginal costs of production) and sometimes pollution, together with amount of energy that will be generated. In a centralized management, the ranking is so that those with the lowest marginal costs are the first ones to be brought online to meet demand, and the plants with the highest marginal costs are the last to be brought on line. Dispatching generation in this way, known as economic dispatch, minimizes the cost of production of electricity. Sometimes generating units must be started out of merit order, due to transmission congestion, system reliability or other reasons. In environmental dispatch, additional considerations concerning reduction of pollution further complicate the power dispatch problem. The basic constraints of the economic dispatch problem remain in place but the model is optimiz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marginal Cost
In economics, the marginal cost is the change in the total cost that arises when the quantity produced is incremented, the cost of producing additional quantity. In some contexts, it refers to an increment of one unit of output, and in others it refers to the rate of change of total cost as output is increased by an infinitesimal amount. As Figure 1 shows, the marginal cost is measured in dollars per unit, whereas total cost is in dollars, and the marginal cost is the slope of the total cost, the rate at which it increases with output. Marginal cost is different from average cost, which is the total cost divided by the number of units produced. At each level of production and time period being considered, marginal cost includes all costs that vary with the level of production, whereas costs that do not vary with production are fixed. For example, the marginal cost of producing an automobile will include the costs of labor and parts needed for the additional automobile but not the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Policy Act Of 2005
The Energy Policy Act of 2005 () is a federal law signed by President George W. Bush on August 8, 2005, at Sandia National Laboratories in Albuquerque, New Mexico. The act, described by proponents as an attempt to combat growing energy problems, changed US energy policy by providing Energy subsidies#Allocation of subsidies in the United States, tax incentives and loan guarantees for energy production of various types. The most consequential aspect of the law was to greatly increase ethanol production to be blended with gasoline. The law also repealed the Public Utility Holding Company Act of 1935, effective February 2006. Provisions General provisions * the Act increases the amount of biofuel (usually ethanol) that must be mixed with gasoline sold in the United States to by 2006, by 2009 and by 2012; two years later, the Energy Independence and Security Act of 2007 extended the target to by 2022. * Under an amendment in the American Recovery and Reinvestment Act of 2009, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Production
Energy development is the field of activities focused on obtaining sources of energy from natural resources. These activities include production of renewable, nuclear, and fossil fuel derived sources of energy, and for the recovery and reuse of energy that would otherwise be wasted. Energy conservation and efficiency measures reduce the demand for energy development, and can have benefits to society with improvements to environmental issues. Societies use energy for transportation, manufacturing, illumination, heating and air conditioning, and communication, for industrial, commercial, and domestic purposes. Energy resources may be classified as primary resources, where the resource can be used in substantially its original form, or as secondary resources, where the energy source must be converted into a more conveniently usable form. Non-renewable resources are significantly depleted by human use, whereas renewable resources are produced by ongoing processes that can susta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Power
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Standard prefixes apply to watts as with other SI units: thousands, millions and billions of watts are called kilowatts, megawatts and gigawatts respectively. A common misconception is that electric power is bought and sold, but actually electrical energy is bought and sold. For example, electricity is sold to consumers in kilowatt-hours (kilowatts multiplied by hours), because energy is power multiplied by time. Electric power is usually produced by electric generators, but can also be supplied by sources such as electric batteries. It is usually supplied to businesses and homes (as domestic mains electricity) by the electric power industry through an electrical grid. Electric power can be delivered over long distances by transmission lines and used for applications such as motion, light or heat with high efficiency. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Commitment Problem In Electrical Power Production
The unit commitment problem (UC) in electrical power production is a large family of mathematical optimization problems where the production of a set of electrical generators is coordinated in order to achieve some common target, usually either matching the energy demand at minimum cost or maximizing revenue from electricity production. This is necessary because it is difficult to store electrical energy on a scale comparable with normal consumption; hence, each (substantial) variation in the consumption must be matched by a corresponding variation of the production. Coordinating generation units is a difficult task for a number of reasons: * the number of units can be large (hundreds or thousands); * there are several types of units, with significantly different energy production costs and constraints about how power can be produced; * generation is distributed across a vast geographical area (e.g., a country), and therefore the response of the electrical grid, itself a highly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Market
In a broad sense, an electricity market is a system that facilitates the exchange of electricity-related goods and services. During more than a century of evolution of the electric power industry, the economics of the electricity markets had undergone enormous changes for reasons ranging from the technological advances on supply and demand sides to politics and ideology. A restructuring of electric power industry at the turn of the 21st century involved replacing the vertically integrated and tightly regulated "traditional" electricity market with multiple competitive markets for electricity generation, transmission, distribution, and retailing. The traditional and competitive market approaches loosely correspond to two visions of industry: the deregulation was transforming electricity from a public service (like sewerage) into a tradable good (like crude oil). As of 2020s, the traditional markets are still common in some regions, including large parts of the United Stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Networks
A neural network is a network or circuit of biological neurons, or, in a modern sense, an artificial neural network, composed of artificial neurons or nodes. Thus, a neural network is either a biological neural network, made up of biological neurons, or an artificial neural network, used for solving artificial intelligence (AI) problems. The connections of the biological neuron are modeled in artificial neural networks as weights between nodes. A positive weight reflects an excitatory connection, while negative values mean inhibitory connections. All inputs are modified by a weight and summed. This activity is referred to as a linear combination. Finally, an activation function controls the amplitude of the output. For example, an acceptable range of output is usually between 0 and 1, or it could be −1 and 1. These artificial networks may be used for predictive modeling, adaptive control and applications where they can be trained via a dataset. Self-learning resulting from e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bees Algorithm
In computer science and operations research, the bees algorithm is a population-based search algorithm which was developed by Pham, Ghanbarzadeh et al. in 2005.Pham DT, Ghanbarzadeh A, Koc E, Otri S, Rahim S and Zaidi M. The Bees Algorithm. Technical Note, Manufacturing Engineering Centre, Cardiff University, UK, 2005. It mimics the food foraging behaviour of honey bee colonies. In its basic version the algorithm performs a kind of neighbourhood search combined with global search, and can be used for both combinatorial optimization and continuous optimization. The only condition for the application of the bees algorithm is that some measure of distance between the solutions is defined. The effectiveness and specific abilities of the bees algorithm have been proven in a number of studies.Pham, D.T., Castellani, M. (2009)The Bees Algorithm – Modelling Foraging Behaviour to Solve Continuous Optimisation Problems Proc. ImechE, Part C, 223(12), 2919-2938.Nasrinpour, H. R., Massah Bavani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Flow Study
In power engineering, the power-flow study, or load-flow study, is a numerical analysis Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic computation, symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of ... of the flow of electric power in an interconnected system. A power-flow study usually uses simplified notations such as a one-line diagram and per-unit system, and focuses on various aspects of AC power parameters, such as voltages, voltage angles, real power and reactive power. It analyzes the power systems in normal steady-state operation. Power-flow or load-flow studies are important for planning future expansion of power systems as well as in determining the best operation of existing systems. The principal information obtained from the power-flow study is the magnitude and phase angle of the voltage at each busbar, bus, and the real and rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagrange Multiplier
In mathematical optimization, the method of Lagrange multipliers is a strategy for finding the local maxima and minima of a function subject to equality constraints (i.e., subject to the condition that one or more equations have to be satisfied exactly by the chosen values of the variables). It is named after the mathematician Joseph-Louis Lagrange. The basic idea is to convert a constrained problem into a form such that the derivative test of an unconstrained problem can still be applied. The relationship between the gradient of the function and gradients of the constraints rather naturally leads to a reformulation of the original problem, known as the Lagrangian function. The method can be summarized as follows: in order to find the maximum or minimum of a function f(x) subjected to the equality constraint g(x) = 0, form the Lagrangian function :\mathcal(x, \lambda) = f(x) + \lambda g(x) and find the stationary points of \mathcal considered as a function of x and the Lagrange mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slack Bus
In electrical power systems a slack bus (or swing bus), defined as a Vδ bus, is used to balance the active power , P, and reactive power , Q, in a system while performing load flow studies. The slack bus is used to provide for system losses by emitting or absorbing active and/or reactive power to and from the system. Load flow studies For power systems engineers, a load flow study explains the power system conditions at various intervals during operation. It aims to minimize the difference between the calculated and actual quantities. Here, the slack bus can contribute to the minimization by having an unconstrained real and reactive power input. P_i=P_-P_ \Delta P_i=P_i-P_ \Delta Q_i=Q_i-Q_ The use of a slack bus has an inherent disadvantage when dealing with uncertain input variables: the slack bus must absorb all uncertainties arising from the system and thus must have the widest possible nodal power distributions. Even moderate amounts of uncertainty in a large system m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
