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A new scheme for real time operation of a microgrid comprising of thermal generators has been introduced. This scheme builds on the fact that economic dispatch can be converted from an optimization problem that is activated only in discrete instants of time into a feedback control problem that continuously adjusts the generators' set points. However, set point adjustment using control-based Economic...
The use of renewable energy sources, such as wind power, is of major importance in future power grids for economic and environmental reasons, while the intermittent and stochastic nature of such energy brings challenges to system dispatch. Application of the virtual power plant (VPP) concept is one of the promising ways to improve utilization of renewable power. Among the many issues of practically...
This paper proposes a group of Evolutionary Algorithms: Black Hole (BH) algorithm, Biogeography Based Optimization (BBO) algorithm and Differential Evolution (DE) algorithms to solve the economic dispatch problem incorporating the wind energy (EDIW) uncertainty. The proposed methods have a simple procedure to find a near optimal solution for the non-smooth and non-convex problems. There are many constraints...
There is a global trend of deploying distributed grid scale storages in power systems for specific applications like, renewable integration, peak load management, congestion management, etc. Due to high capital investment, return on investment (ROI) for grid scale storage for any specific application is not lucrative enough for investors. However, if these storages are used across multiple applications,...
In this work, we model a low-power microgrid based on the distribution grid of the University of Nariño, Colombia. The model includes photovoltaic, wind, microturbines, and fuel cell generators to satisfy the demanded power in the campus, according to measured demand profiles in the low voltage side. The design and simulation are performed in SimPowerSystems simplifying the low-level controllers to...
This paper considers the non-convex Economic Dispatch Problem (EDP) with power losses, prohibited operating zones, and generation cost functions modeling both valve-point loading effects and multiple fuel options. This constrained problem is stated as an unconstrained problem by using the augmented Lagrange formulation, while introducing Lagrange multipliers and penalty parameters. Then, a genetic...
In a deregulated power system, energy prices throughout the network will be characterised and depending on the existence of transmission constraints. As power flow violates transmission constraints, redispatching generating units is required and this will cause the price at every node to vary. This manuscript introduces a scheme for economic redispatch model based on DC optimal power flow taking into...
Under high penetration of wind and solar, the power system is facing the challenge to maintain the balance between generation and load due to the insufficient ramping capability. To resolve this challenge, a new market mechanism was proposed by many ISOs to add the flexible ramping constraints or flexible ramping product to maintain the ramping flexibility in addressing net load uncertainty and variability...
In this paper, a model is presented to solve the problem of combined heat and power (CHP) dispatch. The system under consideration consists of both thermal generators and wind turbines. The wind power is a random variable following the Beta distribution, which is mainly used for the short-term forecasting. In the proposed model, the probability of wind power is included in the constraint set. A computer...
Day-Ahead Unit Commitment is a typical business process of regional transmission organizations (RTO) and some vertically integrated utilities to ensure enough generation capacity is committed day-ahead to meet the load for the next day. In many cases, transmission constraints are required to be taken into consideration under the framework of security-constrained unit commitment (SCUC). Transmission...
Wind energy is beneficial both economically and environmentally, while its utilization levels are still far from satisfactory and has plenty of room to be improved. One way to achieve this is to make use of the heat storage in some of the thermal generators to obtain fast ramping capabilities, so that they can catch up with the fluctuating and intermittent wind energy. Output characteristics of such...
This paper presents a multi-objective Simulated Annealing Optimization to solve a Dynamic Generation Dispatch problem. In this work, the problem is formulated as a multi-objective one with two competing functions, namely economic cost and emission functions, subject to different constraints. The inequality constraints considered are the generating unit capacity limits while the equality constraint...
Power system operators schedule additional capacity above or below the amount required to meet the expected demand at any time interval to ensure reliable operation. This excess capacity is known as operating reserve. This reserve helps protect against the inherent variability and uncertainty found in the system. As more variable generation resources are connected to the system, the amount of variability...
Economic dispatch is one of the optimization problems in the power system operation and planning in which the total cost of generation is minimized while supplying the demand and losses. The ED problem have cost functions which are non-smooth curves with equality and inequality constraints. Conventional methods have drawbacks of high convergence time and inherent sub optimality. So the researchers...
This paper presents a two-layered framework for managing multi-interval economic dispatch with both transmission and ramping constraints in electric energy systems with a large penetration of variable resources. The proposed model is aimed at ensuring that there is sufficient flexibility in the dispatch to manage large net load ramp events while observing the transmission constraints in the power...
This work proposes a new meta-heuristic called Grey Wolf Optimizer (GWO) which inspired by grey wolves (Canis lupus). The GWO algorithm mimics the leadership hierarchy and hunting mechanism of grey wolves in nature. Four types of grey wolves such as alpha, beta, delta, and omega are employed for simulating the leadership hierarchy. In addition, the three main steps of hunting, searching for prey,...
This paper aimed at exploring the performance of Particle Swarm Optimisation with Exponentially Varying Inertia Weight Factor (PSO-EVIWF) for solving Multi-Area Economic Dispatch (MAED) problem with tie line constraints considering valve-point loading in each area. The effectiveness of the proposed algorithm has been verified on 4 interconnected areas with 16 generators standard test system. The paper...
Microgrid combines with Distributed Energy Resources (DERs), energy storage, and controllable loads. It is connected to the maingrid through the point of common coupling (PCC). Economic dispatch using reduced gradient method is implemented for the optimization of energy in the microgrid using MATLAB. The optimization is obtained by minimizing the cost function of the system while meeting the load...
Due to the fluctuation and intermittency of wind power, it is necessary for power systems to provide flexible power to ensure the power balance of supply and demand. Meanwhile, as the increasing installed capacity of wind power, more flexible power is required, and the amount would be significant and the balancing cost would be more expensive. In this paper, the balancing cost is calculated from the...
It is known that in some cases, switching some transmission lines of an electric power system off may improve the optimal economic dispatch cost. This modification of the economic dispatch problem is known as optimal transmission line switching. Unfortunately, the modified problem involves binary decision variables which make the problem difficult to solve for large-scale power systems. This paper...
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