9 research outputs found

    Wind Integrated Thermal Unit Commitment Solution Using Grey Wolf Optimizer

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    The augment of ecological shield and the progressive exhaustion of traditional fossil energy sources have increased the interests in integrating renewable energy sources into existing power system. Wind power is becoming worldwide a significant component of the power generation portfolio. Profuse literature have been reported for the thermal Unit Commitment (UC) solution. In this work, the UC problem has been formulated by integrating wind power generators along with thermal power system. The Wind Generator Integrated UC (WGIUC) problem is more complex in nature, that necessitates a promising optimization tool. Hence, the modern bio-inspired algorithm namely, Grey Wolf Optimization (GWO) algorithm has been chosen as the main optimization tool and real coded scheme has been incorporated to handle the operational constraints. The standard test systems are used to validate the potential of the GWO algorithm. Moreover, the ramp rate limits are also included in the mathematical WGIUC formulation. The simulation results prove that the intended algorithm has the capability of obtaining economical resolutions with good solution quality

    A Memetic Evolutionary Multi-Objective Optimization Method for Environmental Power Unit Commitment

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    International audienceA multi-objective power unit commitment problem is framed to consider simultaneously the objectives of minimizing the operation cost and minimizing the emissions from the generation units. To find the solution of the optimal schedule of the generation units, a memetic evolutionary algorithm is proposed, which combines the non-dominated sorting genetic algorithm-II (NSGA-II) and a local search algorithm. The power dispatch sub-problem is solved by the weighed-sum lambda-iteration approach. The proposed method has been tested on systems composed by 10 and 100 generation units for a 24 hour demand horizon. The Pareto-optimal front obtained contains solutions of different trade off with respect to the two objectives of cost and emission, which are superior to those contained in the Pareto-front obtained by the pure NSGA-II. The solutions of minimum cost are shown to compare well with recent published results obtained by single-objective cost optimization algorithms

    A Biased Random Key Genetic Algorithm Approach for Unit Commitment Problem

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    A Biased Random Key Genetic Algorithm (BRKGA) is proposed to find solutions for the unit commitment problem. In this problem, one wishes to schedule energy production on a given set of thermal generation units in order to meet energy demands at minimum cost, while satisfying a set of technological and spinning reserve constraints. In the BRKGA, solutions are encoded by using random keys, which are represented as vectors of real numbers in the interval [0, 1]. The GA proposed is a variant of the random key genetic algorithm, since bias is introduced in the parent selection procedure, as well as in the crossover strategy. Tests have been performed on benchmark large-scale power systems of up to 100 units for a 24 hours period. The results obtained have shown the proposed methodology to be an effective and efficient tool for finding solutions to large-scale unit commitment problems. Furthermore, from the comparisons made it can be concluded that the results produced improve upon some of the best known solutions

    Operational flexibility for increasing renewable energy penetration level by modified enhanced priority list method

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    The increasing concerns on climate change and the need for a more sustainable grid, recently has seen a fast expansion of renewable energy sources (RES). This leads to complexities in system balancing between the load and the integrated RES generation, as a result of increased levels of system variability and uncertainty. The concept of flexibility describes the capability of the power system to maintain a balance between generation and the load under uncertainty. Therefore, system operators need to develop flexibility measuring technique to manage the sudden intermittency of net-load. Current flexibility metrics are not exhaustive enough to capture the different aspects of the flexibility requirement assessment of the power systems. Furthermore, one of their demerits is that the start-up cost is not considered together with the other technical parameters. Hence, this thesis proposes a method that improves the assessment accuracy of individual thermal units and overall generation system. Additionally, a new flexibility metric for effective planning of system operations is proposed. The proposed metric considers technoeconomic flexibility indicators possessed by generation units. A new ranking for Flexibility Ranked Enhanced Priority List (FREPL) method for increasing share of renewable energy is proposed as well. The assessment is conducted using technical and economic flexibility indicators characteristics of the generating units. An analytical hierarchy process is utilized to assign weights to these indicators in order to measure their relative significance. Next, a normalization process is executed and then followed by a linear aggregation to produce the proposed flexibility metric. Flexibility and cost ranking are coupled in order to improve the FREPL. The proposed technique has been tested using both IEEE RTS-96 test system and IEEE 10-units generating system. The developed method is integrated with the conventional unit commitment problem in order to assist the system operators for optimal use of the generation portfolios of their power system networks. The results demonstrate that the developed metric is robust and superior to the existing metrics, while the proposed Enhanced Priority List characterizes the system’s planned resources that could be operated in a sufficiently flexible manner. The net-load profile has been enhanced and the penetration level of wind power has been upgraded from 28.9% up to 37.2% while the penetration level of solar power has been upgraded from 14.5% up to 15.1%

    Concurrent design of facility layout and flow-based department formation

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    The design of facility layout takes into account a number of issues including the formation of departments, the layout of these, the determination of the material handling methods to be used, etc. To achieve an efficient layout, these issues should be examined simultaneously. However, in practice, these problems are generally formulated and solved sequentially due to the complicated nature of the integrated problem. Specifically, there is close interaction between the formation of departments and layout of these departments. These problems are treated as separate problems that are solved sequentially. This procedure is mainly due to the complexity of each problem and the interrelationships between them. In this research, we take a first step toward integrating the flow-based department formation and departmental layout into comprehensive mathematical models and develop appropriate solution procedures. It is expected that these mathematical models and the solution procedures developed will generate more efficient manufacturing system designs, insights into the nature of the concurrent facility layout problem, and new research directions

    The Effect of Magnetic Field on HTS Leads What Happens when thePower Fails at RAL?

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