Journal articles: 'Grid generation; Grid solving; Optimisation'

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Koivisto, Matti, Juan Gea‐Bermúdez, and Poul Sørensen. "North Sea offshore grid development: combined optimisation of grid and generation investments towards 2050." IET Renewable Power Generation 14, no. 8 (February 26, 2020): 1259–67. http://dx.doi.org/10.1049/iet-rpg.2019.0693.

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Zhou, Yuancheng, and Markus Hegland. "The application of sparse grid quadrature in solving stochastic optimisation problems." ANZIAM Journal 60 (June 19, 2019): 16. http://dx.doi.org/10.21914/anziamj.v60i0.14060.

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Martynenko, S. I. "Remarks on Generation of the Orthogonal Structured Grids." Herald of the Bauman Moscow State Technical University. Series Natural Sciences, no. 82 (2019): 16–26. http://dx.doi.org/10.18698/1812-3368-2019-1-16-26.

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Grid generation techniques have contributed significantly toward the application of mathematical modeling in large-scale engineering problems. The structured grids have the advantage that very robust and parallel computational algorithms have been proposed for solving (initial-)boundary value problems. Orthogonal grids make it possible to simplify an approximation of the differential equations and to increase computation accuracy. Opportunity of the orthogonal structured grid generation for solving two- and three-dimensional (initial-)boundary value problems is analyzed in the article in assumption that isolines or isosurfaces of d (=2,3) functions form this grid. Condition of the isolines/isosurfaces orthogonality is used for formulation of the boundary value problems, the solutions of which will be form the orthogonal grid. A differential substitution is proposed to formulate the boundary value problems directly from the orthogonality condition of the grid. The substitution leads to the general partial differrential equations with undetermined coefficients. In the two-dimensional case, it is shown that the orthogonal grid generation is equivalent to the solution of partial differential equations of either elliptic or hyperbolic type. In three-dimensional domains, an orthogonal grid can be generated only in special cases. The obtained results are useful for mathematical modeling of the complex physicochemical processes in the technical devices

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Qiu, Lu, and Yan Song Li. "Micro-Grid System Integrated with GSHP." Advanced Materials Research 1092-1093 (March 2015): 288–91. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.288.

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In the past few decades, power system has developed into a large-scale network system of centralized electricity generation and long-distance transmission. But in recent years, electrical load has increasing, while the grid has not developed simultaneously, it makes transmission capacity of long-distance transmission lines increase, so as the decline of stability and security of power grid. In order to achieve the goal of not only increasing utilization of renewable energy, but also solving the drawbacks of large-scale power systems, implementing distributed power generation is an effective way. Despite the advantages of distributed generation, there are many problems in itself, for example, the high cost of distributed generation stand-alone access and control difficulties. In addition, distributed generation is a non-controllable source for large grid. Then in the beginning of this century, scholars have proposed the concept of micro-grid.

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Parashar, Sonam, Anil Swarnkar, Khaleequr Rehman Niazi, and Nikhil Gupta. "Modified elephant herding optimisation for economic generation co-ordination of DERs and BESS in grid connected micro-grid." Journal of Engineering 2017, no. 13 (January 1, 2017): 1969–73. http://dx.doi.org/10.1049/joe.2017.0673.

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Du, Lingyu, Qiuhe Ma, Jin Ben, Rui Wang, and Jiahao Li. "Duality and Dimensionality Reduction Discrete Line Generation Algorithm for a Triangular Grid." ISPRS International Journal of Geo-Information 7, no. 10 (September 27, 2018): 391. http://dx.doi.org/10.3390/ijgi7100391.

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Vectors are a key type of geospatial data, and their discretization, which involves solving the problem of generating a discrete line, is particularly important. In this study, we propose a method for constructing a discrete line mathematical model for a triangular grid based on a “weak duality” hexagonal grid, to overcome the drawbacks of existing discrete line generation algorithms for a triangular grid. First, a weak duality relationship between triangular and hexagonal grids is explored. Second, an equivalent triangular grid model is established based on the hexagonal grid, using this weak duality relationship. Third, the two-dimensional discrete line model is solved by transforming it into a one-dimensional optimal wandering path model. Finally, we design and implement the dimensionality reduction generation algorithm for a discrete line in a triangular grid. The results of our comparative experiment indicate that the proposed algorithm has a computation speed that is approximately 10 times that of similar existing algorithms; in addition, it has better fitting effectiveness. Our proposed algorithm has broad applications, and it can be used for real-time grid transformation of vector data, discrete global grid system (DGGS), and other similar applications.

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Xu, Jian Yuan, Jia Jue Li, Jie Jun Zhang, and Yu Zhu. "Power Reserve Classification and Control for Peaking Balance with Intermittent Generation Grid." Applied Mechanics and Materials 521 (February 2014): 252–55. http://dx.doi.org/10.4028/www.scientific.net/amm.521.252.

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The problem of intermittent generation peaking is highly concerned by the grid operator. To build control model for solving unbalance of peaking is great necessary. In this paper, we propose reserve classification control model which contain constant reserve control model with real-time reserve control model to guide the peaking balance of the grid with intermittent generation. The proposed model associate time-period constant reserve control model with real-time reserve control model to calculate, and use the peaking margin as intermediate variable. Therefore, the model solutions which are the capacity of reserve classification are obtained. The grid operators use the solution to achieve the peaking balance control. The proposed model was examined by real grid operation case, and the results of the case demonstrate the validity of the proposed model.

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Oldham, D., J. H. Davies, and T. N. Phillips. "Generic polyhedron grid generation for solving partial differential equations on spherical surfaces." Computers & Geosciences 39 (February 2012): 11–17. http://dx.doi.org/10.1016/j.cageo.2011.06.004.

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Heitkoetter, Wilko, Wided Medjroubi, Thomas Vogt, and Carsten Agert. "Comparison of Open Source Power Grid Models—Combining a Mathematical, Visual and Electrical Analysis in an Open Source Tool." Energies 12, no. 24 (December 11, 2019): 4728. http://dx.doi.org/10.3390/en12244728.

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Power grid models are important in relation to several topics and applications, especially the modelling, optimisation and extension of electrical grids. The significance of grid models is heightened by the increase in renewable energy generation and the challenges associated with its integration into the power grid. However, despite their crucial importance, grid models have generally not been made publicly available for scientific studies or technical analyses. Little information has been published about either the details and methods used in the derivation of these models, or their input and output data. Recently, several projects were initiated in an effort to address this by developing open source grid models and associated data. These projects used different approaches and methods, but most are based on the OpenStreetMap database. The goal of this paper is to compare the different available grid models on the basis of the structure and derivation methods used. Therefore, a novel combination of a graph-theoretical, Geographic Information System (GIS)-based and power-related comparison level is introduced using the open source tool AutoGridComp, which was developed by the authors. The grid models considered in this study are the Scientific Grid Model (SciGRID), GridKit and open street map Transmission Grid Model (osmTGmod) models for Germany.

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Azman, Azarina, Shafrida Sahrani, Kismet Hong Ping, and Dayang Azra Awang Mat. "A New Approach for Solving Inverse Scattering Problems with Overset Grid Generation Method." TELKOMNIKA (Telecommunication Computing Electronics and Control) 15, no. 2 (March 1, 2017): 820. http://dx.doi.org/10.12928/telkomnika.v15i1.6127.

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Azman, Azarina, Shafrida Sahrani, Kismet Hong Ping, and Dayang Azra Awang Mat. "A New Approach for Solving Inverse Scattering Problems with Overset Grid Generation Method." TELKOMNIKA (Telecommunication Computing Electronics and Control) 15, no. 2 (March 1, 2017): 820. http://dx.doi.org/10.12928/telkomnika.v15i2.6127.

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Wang, Liqun, Songming Hou, and Liwei Shi. "A Numerical Method for Solving Elliptic Interface Problems Using Petrov-Galerkin Formulation with Adaptive Refinement." Mathematical Problems in Engineering 2018 (September 10, 2018): 1–12. http://dx.doi.org/10.1155/2018/3721258.

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Elliptic interface problems have wide applications in engineering and science. Non-body-fitted grid has the advantage of saving the cost of mesh generation. In this paper, we propose a Petrov-Galerkin formulation using non-body-fitted grid for solving elliptic interface problems. In this method, adaptive mesh refinement is employed for cells with large errors. The new mesh still has all triangles being right triangles of the same shape. Numerical experiments show side-by-side comparison that to obtain the same accuracy, our new method has much less overall CPU time compared with the previous method even with some cost on mesh generation.

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De Din, Edoardo, Marco Pau, Ferdinanda Ponci, and Antonello Monti. "A Coordinated Voltage Control for Overvoltage Mitigation in LV Distribution Grids." Energies 13, no. 8 (April 17, 2020): 2007. http://dx.doi.org/10.3390/en13082007.

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The design of intelligent strategies for grid management is a cost-effective solution to increase the hosting capacity of distribution grids without investing in the reinforcement of the grid assets. This paper presents a distributed voltage control algorithm to coordinate Energy Storage Systems (ESSs) and Distributed Generation (DG) in a scenario of high renewable penetration. The proposed control algorithm relies on a dual decomposition approach and aims at mitigating possible voltage rise events occurring in the Low Voltage (LV) grid by solving an optimization problem of power minimization. Instead of using local control strategies, in the proposed solution, the voltage control burden is distributed among all the available resources in the grid, which cooperate to resolve the existing voltage violations. The performance of the developed voltage control has been tested under realistic distribution grid scenarios, using stochastic load profiles together with photovoltaic generation profiles obtained in the presence of both clear sky and cloudy sky conditions. The algorithm is also compared to a strategy that considers only DG management, highlighting the benefits associated to the proposed coordination of DG and Energy Storage Systems (ESSs).

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Cerchio, Marco, Francesco Gullí, Maurizio Repetto, and Antonino Sanfilippo. "Hybrid Energy Network Management: Simulation and Optimisation of Large Scale PV Coupled with Hydrogen Generation." Electronics 9, no. 10 (October 20, 2020): 1734. http://dx.doi.org/10.3390/electronics9101734.

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The power production of electrical Renewable Energy Sources (RES), mainly PV and wind energy, is affected by their primary source of energy: solar radiation value or wind strength. Electrical networks with a large share of these sources must manage temporal imbalances of supply and demand. Hybrid Energy Networks (HEN) can mitigate the effects of this unbalancing by providing a connection between the electricity grid and and other energy vectors such as heat, gas or hydrogen. These couplings can activate synergies among networks that, all together, increase the share of renewable sources helping a decarbonisation of the energy sector. As the energy system becomes more and more complex, the need for simulation and optimisation tools increases. Mathematical optimisation can be used to look for a management strategy maximising a specific target, for instance economical, i.e. the minimum management cost, or environmental as the best exploitation or RES. The present work presents a Mixed Integer Linear Programming (MILP) optimisation procedure that looks for the minimum running cost of a system made up by a large-scale PV plant where hydrogen production, storage and conversion to electricity is present. In addition, a connection to a natural gas grid where hydrogen can be sold is considered. Different running strategies are studied and analysed as functions of electricity prices and other forms of electrical energy exploitation.

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Sapetina, Anna, Ivan Ulyanichev, and Boris Glinskiy. "The grid codes generation for solving problems of the cosmic plasma hydrodynamics on supercomputers." Journal of Physics: Conference Series 1336 (November 2019): 012012. http://dx.doi.org/10.1088/1742-6596/1336/1/012012.

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Nadhirah Sam’on, Izni, Zuhaila Mat Yasin, and Zuhaina Zakaria. "Ant Lion Optimizer for Solving Unit Commitment Problem in Smart Grid System." Indonesian Journal of Electrical Engineering and Computer Science 8, no. 1 (October 1, 2017): 129. http://dx.doi.org/10.11591/ijeecs.v8.i1.pp129-136.

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<p>This paper proposed the integration of solar energy resources into the conventional unit commitment. The growing concern about the depletion of fossil fuels increased the awareness on the importance of renewable energy resources, as an alternative energy resources in unit commitment operation. However, the present renewable energy resources is intermitted due to unpredicted photovoltaic output. Therefore, Ant Lion Optimizer (ALO) is proposed to solve unit commitment problem in smart grid system with consideration of uncertainties .ALO is inspired by the hunting appliance of ant lions in natural surroundings. A 10-unit system with the constraints, such as power balance, spinning reserve, generation limit, minimum up and down time constraints are considered to prove the effectiveness of the proposed method. The performance of proposed algorithm are compared with the performance of Dynamic Programming (DP). The results show that the integration of solar energy resources in unit<em> commitment scheduling can improve the total operating cost significantly. </em></p>

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Dkhili, Nouha, Julien Eynard, Stéphane Thil, and Stéphane Grieu. "Resilient Predictive Control Coupled with a Worst-Case Scenario Approach for a Distributed-Generation-Rich Power Distribution Grid." Clean Technologies 3, no. 3 (August 30, 2021): 629–55. http://dx.doi.org/10.3390/cleantechnol3030038.

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In a context of accelerating deployment of distributed generation in power distribution grid, this work proposes an answer to an important and urgent need for better management tools in order to ‘intelligently’ operate these grids and maintain quality of service. To this aim, a model-based predictive control (MPC) strategy is proposed, allowing efficient re-routing of power flows using flexible assets, while respecting operational constraints as well as the voltage constraints prescribed by ENEDIS, the French distribution grid operator. The flexible assets used in the case study—a low-voltage power distribution grid in southern France—are a biogas plant and a water tower. Non-parametric machine-learning-based models, i.e., Gaussian process regression (GPR) models, are developed for intraday forecasting of global horizontal irradiance (GHI), grid load, and water demand, to better anticipate emerging constraints. The forecasts’ quality decreases as the forecast horizon grows longer, but quickly stabilizes around a constant error value. Then, the impact of forecasting errors on the performance of the control strategy is evaluated, revealing a resilient behaviour where little degradation is observed in terms of performance and computation cost. To enhance the strategy’s resilience and minimise voltage overflow, a worst-case scenario approach is proposed for the next time step and its contribution is examined. This is the main contribution of the paper. The purpose of the min–max problem added upstream of the main optimisation problem is to both anticipate and minimise the voltage overshooting resulting from forecasting errors. In this min–max problem, the feasible space defined by the confidence intervals of the forecasts is searched, in order to determine the worst-case scenario in terms of constraint violation, over the next time step. Then, such information is incorporated into the decision-making process of the main optimisation problem. Results show that these incidents are indeed reduced thanks to the min–max problem, both in terms of frequency of their occurrence and the total surface area of overshooting.

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Patil, Rakesh, Jarod Kelly, Zoran Filipi, and Hosam Fathy. "A Framework for the Integrated Optimization of Charging and Power Management in Plug-in Hybrid Electric Vehicles." Vehicular Technology, IEEE Transactions on 62, no. 6 (July 2013): 2402–12. http://dx.doi.org/10.1109/tvt.2013.2243850.

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This paper develops a dynamic programming (DP)-based framework for simultaneously optimizing the charging and power management of a plug-in hybrid electric vehicle (PHEV). These two optimal control problems relate to activities of the PHEV on the electric grid (i.e., charging) and on the road (i.e., power management). The proposed framework solves these two problems simultaneously to avoid loss of optimality resulting from solving them separately. The framework furnishes optimal trajectories of PHEV states and control inputs over a 24-h period. We demonstrate the framework for 24-h scenarios with two driving trips and different power grid generation mixes. The results show that addressing the aforementioned optimization problems simultaneously can elucidate valuable insights. For example, for the chosen daily driving scenario, grid generation mixes, and optimization objective, it is shown that it is not always optimal to completely charge a battery before each driving trip. In addition, reduction in CO2resulting from the synergistic interaction of PHEVs with an electric grid containing a significant amount of wind power is studied. The main contribution of this paper to the literature is a framework that makes it possible to evaluate tradeoffs between charging and on-road power management decisions.

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Manisha, N. A., Sachin Bhati, Prerna Gaur, and Diwaker Pathak. "Novel fuzzy-assisted nonlinear optimal power generation method for grid-connected SPV system with TLBO optimisation." International Journal of Renewable Energy Technology 12, no. 2 (2021): 144. http://dx.doi.org/10.1504/ijret.2021.10038105.

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Manisha, N. A., Sachin Bhati, Prerna Gaur, and Diwaker Pathak. "Novel fuzzy-assisted nonlinear optimal power generation method for grid-connected SPV system with TLBO optimisation." International Journal of Renewable Energy Technology 12, no. 2 (2021): 144. http://dx.doi.org/10.1504/ijret.2021.115262.

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Schellenberg, Christoph, Laurentiu Dimache, and John Lohan. "Grid-edge technology - Exploring the flexibility potential of a heat pump and thermal energy storage system." E3S Web of Conferences 111 (2019): 06002. http://dx.doi.org/10.1051/e3sconf/201911106002.

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Grid-edge technologies (GET) enable and amplify the impact of three emerging energy system trends: electrification, decentralisation, and digitalisation. Smart grid integrated heat pumps with thermal energy storage enable both the electrification of heating and decentralised demand response. Such power-to-heat technologies simultaneously decarbonise heating and facilitate the grid integration of more variable renewable electricity in a cost-effective manner. This may help to explore and exploit untapped wind generation potential. This study explores the flexibility potential of a domestic scale heat pump with thermal energy storage in a typical Irish home in December. The system is simulated to investigate demand-side flexibility and sensitivity to both heat pump and thermal storage capacities for three days with wind energy shares of 7%, 25%, and 60%. Using real-time electricity prices and optimising for operational cost, the implicit demand flexibility potential is quantified with different combinations of heat pump power and storage capacity. The results suggest that 33-100% of critical loads can be shifted dynamically to low-cost periods. Optimised system design depends on local climate, heat demand profile, optimisation horizon, and the type of heat pump. Optimisation with genetic algorithm yielded near-global optimal results approximately 40 times faster than with exhaustive enumeration.

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Wu, Zhaochun, Jianping Luo, and Jingmei Feng. "A novel algorithm for solving the classical Stefan problem." Thermal Science 15, suppl. 1 (2011): 39–44. http://dx.doi.org/10.2298/tsci11s1039w.

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A novel algorithm for solving the classic Stefan problem is proposed in the paper. Instead of front tracking, we preset the moving interface locations and use these location coordinates as the grid points to find out the arrival time of moving interface respectively. Through this approach, the difficulty in mesh generation can be avoided completely. The simulation shows the numerical result is well coincident with the exact solution, implying the new approach performs well in solving this problem.

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Chen, Zi Ying, Jia Lin Hu, Jia Yao Li, and Wei Xun Long. "Overview and Prospects of Black Start." Applied Mechanics and Materials 533 (February 2014): 401–8. http://dx.doi.org/10.4028/www.scientific.net/amm.533.401.

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With the rapid development of power grid, black start has been an indispensable part of power grid construction, and the gradually mature microgrid technology will play an important role in solving power system problems. Otherwise, plug-in electric vehicle will become an important load in future power grid. The black start concept, research status, black start scheme development and its verification are stated in detail; distributed generation and microgrid are introduced; the strategy about taking microgrid as black start power sources is proposed; and key technical problems existing on the combination of black start, microgrid and plug-in electric vehicle are explored according to the microgrid control and operation characteristics. On the basis of summarizing black start and microgrid research development and achievements in the globe, this paper discusses prospects of black start and provides new views and suggestions for its further research.

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Engwirda, Darren. "JIGSAW-GEO (1.0): locally orthogonal staggered unstructured grid generation for general circulation modelling on the sphere." Geoscientific Model Development 10, no. 6 (June 6, 2017): 2117–40. http://dx.doi.org/10.5194/gmd-10-2117-2017.

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Abstract. An algorithm for the generation of non-uniform, locally orthogonal staggered unstructured spheroidal grids is described. This technique is designed to generate very high-quality staggered Voronoi–Delaunay meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather prediction. Using a recently developed Frontal-Delaunay refinement technique, a method for the construction of high-quality unstructured spheroidal Delaunay triangulations is introduced. A locally orthogonal polygonal grid, derived from the associated Voronoi diagram, is computed as the staggered dual. It is shown that use of the Frontal-Delaunay refinement technique allows for the generation of very high-quality unstructured triangulations, satisfying a priori bounds on element size and shape. Grid quality is further improved through the application of hill-climbing-type optimisation techniques. Overall, the algorithm is shown to produce grids with very high element quality and smooth grading characteristics, while imposing relatively low computational expense. A selection of uniform and non-uniform spheroidal grids appropriate for high-resolution, multi-scale general circulation modelling are presented. These grids are shown to satisfy the geometric constraints associated with contemporary unstructured C-grid-type finite-volume models, including the Model for Prediction Across Scales (MPAS-O). The use of user-defined mesh-spacing functions to generate smoothly graded, non-uniform grids for multi-resolution-type studies is discussed in detail.

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Mekhamer, Said, Almoataz Abdelaziz, and Mostafa Algabalawy. "Design of hybrid power generation systems connected to utility grid and natural gas distribution network." Engineering review 38, no. 2 (2018): 204–14. http://dx.doi.org/10.30765/er.38.2.8.

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Hybrid power generation system (HPGS) is an active research area, which is in need of a continuous improvement. It represents the best solution for the most complex problems facing the world in the last decades. These problems are known as the shortage of energy, or lack of electricity, which logically are the results of the continuous increasing demand. Therefore, the researchers do their best to overcome all expected roadblocks facing the development, where the most applicable solutions to solve these problems are introduced. In this paper, the HPGS includes; wind turbine (WT), photovoltaic (PV), storage battery (SB), gas turbine (GT), and utility grid (UG). The GT of this system is fueled directly from the natural gas distribution network considering all operational conditions of it, which may be affected by fueling the natural gas for the GT. So, the natural gas distribution network is becoming an important component of the HPGS, and it is included in the HPGS for the first time. Multi meta-heuristic optimization techniques are applied to obtain the components sizing of this system, where cuckoo search algorithm (CSA), firefly algorithm (FA), and flower pollination algorithm (FPA) have been applied. Therefore, this paper introduces a new contribution not only to the new configuration of the HPGS, but also in applying the new optimization techniques as solving tools. The output results are compared to show the effectiveness and the superiority of the applied techniques as well as extract a recommendation for the best solving technique.

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Ouramdane, Oussama, Elhoussin Elbouchikhi, Yassine Amirat, and Ehsan Sedgh Gooya. "Optimal Sizing and Energy Management of Microgrids with Vehicle-to-Grid Technology: A Critical Review and Future Trends." Energies 14, no. 14 (July 10, 2021): 4166. http://dx.doi.org/10.3390/en14144166.

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The topic of microgrids (MGs) is a fast-growing and very promising field of research in terms of energy production quality, pollution reduction and sustainable development. Moreover, MGs are, above all, designed to considerably improve the autonomy, sustainability, and reliability of future electrical distribution grid. At the same time, aspects of MGs energy management, taking into consideration distribution generation systems, energy storage devices, electric vehicles, and consumption components have been widely investigated. Besides, grid architectures including DC, AC, or hybrid power generation systems, energy dispatching problems modelling, operating modes (islanded or grid connected), MGs sizing, simulations and problems solving optimization approaches, and other aspects, have been raised as topics of great interest for both electrical and computer sciences research communities. Furthermore, the United Nations Framework Convention on Climate Change and government policies and incentives have paved the way to massive electric vehicle (EV) deployment. Hence, several research studies have been conducted to investigate the integration of EVs in national power grid and future MGs. Specifically, EV charging stations’ bi-directional power flow control and energy management have been considerably explored. These issues index challenging research topics, which are in most cases still under progress. This paper gives an overview of MGs technology advancement in recent decades, taking into consideration distributed energy generation (DER), energy storage systems (ESS), EVs, and loads. It reviews the main MGs architecture, operating modes, sizing and energy management systems (EMS) and EVs integration.

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Wang, Ying, Zhile Yang, Yuanjun Guo, Bowen Zhou, and Xiaodong Zhu. "A Novel Binary Competitive Swarm Optimizer for Power System Unit Commitment." Applied Sciences 9, no. 9 (April 29, 2019): 1776. http://dx.doi.org/10.3390/app9091776.

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The unit commitment (UC) problem is a critical task in power system operation process. The units realize reasonable start-up and shut-down scheduling and would bring considerable economic savings to the grid operators. However, unit commitment is a high-dimensional mixed-integer optimisation problem, which has long been intractable for current solvers. Competitive swarm optimizer is a recent proposed meta-heuristic algorithm specialized in solving the high-dimensional problem. In this paper, a novel binary competitive swarm optimizer (BCSO) is proposed for solving the UC problem associated with lambda iteration method. To verify the effectiveness of the proposed algorithm, comprehensive numerical studies on different sizes units ranging from 10 to 100 are proposed, and the algorithm is compared with other counterparts. Results clearly show that BCSO outperforms all the other counterparts and is therefore completely capable of solving the UC problem.

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Dyer, Jamie, Christopher Zarzar, Philip Amburn, Robert Dumais, John Raby, and Jeffrey A. Smith. "Defining the Influence of Horizontal Grid Spacing on Ensemble Uncertainty within a Regional Modeling Framework." Weather and Forecasting 31, no. 6 (December 1, 2016): 1997–2017. http://dx.doi.org/10.1175/waf-d-16-0030.1.

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Abstract Numerical weather prediction (NWP) models are limited with respect to initial and boundary condition data and possess an incomplete description of underlying physical processes. To account for this, modelers have adopted the method of ensemble prediction to quantify the uncertainty within a model framework; however, the generation of ensemble members requires considerably more computational time and/or resources than a single deterministic simulation, especially at convection-allowing horizontal grid spacings. One approach to solving this issue is the development of both a large and small horizontal grid spacing model framework over the same domain for ensemble and deterministic simulations, respectively. This approach assumes that model grid spacing has no influence on model uncertainty; therefore, the objective of this paper is to quantify the influence of horizontal grid spacing on the statistical spread of NWP model ensembles over a regional domain. A series of 24-h simulations using the Weather Research and Forecast (WRF) Model are generated over a static domain with horizontal grid spacings of 35, 25, 15, and 9 km, using both a stochastic kinetic energy backscatter scheme and a multiphysics ensemble approach. Results indicate that horizontal grid spacing does influence the magnitude of uncertainty within an ensemble, although the exact magnitude and type of statistical relationship (direct versus inverse) varies by case. As such, at shorter lead times (<12 h) the dominant atmospheric process associated with each event and the type of ensemble being used outweigh the individual impacts of horizontal grid spacing on ensemble spread.

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Tang, Fei, Junjie Pang, Kefei Cheng, and Qianhong Gong. "Multiauthority Traceable Ring Signature Scheme for Smart Grid Based on Blockchain." Wireless Communications and Mobile Computing 2021 (April 9, 2021): 1–9. http://dx.doi.org/10.1155/2021/5566430.

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As the next-generation power grid system, the smart grid can realize the balance of supply and demand and help in communication security and privacy protection. However, real-time power consumption data collection might expose the users’ privacy information, such as their living habits and economic conditions. In addition, during the process of data transmission, it may lead to data inconsistency between the user side and the storage side. Blockchain provides tamper-resistant and traceable characteristics for solving these problems, and ring signature schemes provide an anonymous authentication mechanism. Therefore, in this work, we consider the applications of ring signature scheme in smart grid based on blockchain. We introduce the notion of multi-authority traceable ring signature (MA-TRS) scheme for distributed setting. In our scheme, there is an auditing node that can distinguish the identity of the real signer from the ring without any secret information. Last but not least, we prove that the proposed scheme is unforgeable, anonymous, and traceable.

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Dragomir, Florin, and Otilia Elena Dragomir. "Improvement of Energy Consume from Hybrid Systems Integrating Renewable Energy Sources." Advanced Materials Research 512-515 (May 2012): 1147–50. http://dx.doi.org/10.4028/www.scientific.net/amr.512-515.1147.

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This article proposes a solution for smart grid technologies using renewable energy and has as main result the optimisation of energy generation and consum in a power system with distributed power generation from renewable resources, by designing and implementation an system platform for monitoring and transmission the message (phone via SMS) by consumers. This application make available to consumers real-time information about energy, giving them the opportunity to make smart choices, allowing them to reduce their monthly bills and carbon emissions, reducing also the demand during peak periods and allows a more efficient use of renewable energy resources.

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Pan, Hao, Ming Ding, Rui Bi, and Lei Sun. "Research on Cooperative Planning of Distributed Generation Access to AC/DC Distribution (Micro) Grids Based on Analytical Target Cascading." Energies 12, no. 10 (May 15, 2019): 1847. http://dx.doi.org/10.3390/en12101847.

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With the wide application of distributed generation (DG) and the rapid development of alternating current/direct current (AC/DC) hybrid microgrids, the optimal planning of distributed generation connecting to AC/DC distribution networks/microgrids has become an urgent problem to resolve. This paper presents a collaborative planning method for distributed generation access to AC/DC distribution (micro) grids. Based on the grid structure of the AC/DC distribution network, the typical interconnection structure of the AC/DC hybrid microgrid and AC/DC distribution network is designed. The optimal allocation models of distributed power supply for the AC/DC distribution network and microgrid are established based on analytical target cascading. The power interaction between the distribution network and microgrid is used to establish a coupling relationship, and the augmented Lagrangian penalty function is used to solve the collaborative programming problem. The results of distributed power supply allocation are obtained, solving the problem so that distribution generation with different capacity levels is connected to the power grid system in a single form.

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Mburu, Zack M., Sabyasachi Mondal, Precious Sibanda, and Ram Prakash Sharma. "The Overlapping Grid Spectral Collocation Method for Solving Entropy Generation in Casson Nanofluid Flow Past a Stretching Plate." Journal of Nanofluids 10, no. 1 (March 1, 2021): 45–57. http://dx.doi.org/10.1166/jon.2021.1766.

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The current study investigates the intrinsic irreversibility phenomenon of a mixed convection and electrically conducting couple stress Casson fluid motion over a thermally stretching sheet. We have considered the combined effect of applied magnetic field, Brownian motion, thermal radiation, permeability, Casson parameter, and the stretching parameter on the entropy generation rate of the model. The first and second laws of thermodynamics have been applied to examine the flow problem. The obtained dimensionless structure of highly nonlinear ordinary differential equations is then solved numerically applying the overlapping grid spectral collocation method. This method has high accuracy and converges fast. The approximate solutions for velocity, temperature and concentration are used to evaluate the rate of entropy generation and some physical parameters of the flow. For engineering interest, we have obtained tabular results for the skin friction coefficient, Nusselt number, and the Sherwood number for pertinent parameters. We found that entropy generation rate is minimized when there is an increase in the applied magnetic field, thermophoresis parameter, Casson parameter, Brownian motion, and the energy variance parameter. Further, the entropy generation rate is increased by enhancing the stretching parameter, permeability parameter, the Biot number, and thermal radiation parameter.

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Li, Hong, Yang Liu, and Jianfeng Yang. "A Novel FCS-MPC Method of Multi-Level APF Is Proposed to Improve the Power Quality in Renewable Energy Generation Connected to the Grid." Sustainability 13, no. 8 (April 7, 2021): 4094. http://dx.doi.org/10.3390/su13084094.

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When photovoltaic, wind, energy storage batteries, and other new forms of energy are connected to the grid, power electronic converters are needed, and there are a lot of nonlinear devices in the grid. The characteristics of sustainable energy generation determine the variability and intermittency, which will produce harmonic components. Active power filters (APF) are commonly used in industry for harmonic compensation, so it is of great significance to control APF quickly and effectively. The multi-objective, single-factor, multistep finite control set model predictive control (FCS-MPC) of an APF proposed in this paper is suitable for a multi-objective, multi-level converter control. This method is applied to the three-level APF structure, which changes the traditional three-level FCS-MPC control method. The traditional three-level FCS-MPC includes four control objectives, stable control of the DC-side voltage, power grid harmonic currents generated under non-linear loads, and balance of the capacitor voltage on the DC side when switching frequency. This method uses the redundant switching state of the three-level structure to achieve the voltage balance of the two capacitors on the DC side, which reduces the difficulty of target optimisation caused by the selection of weight factors. Based on the multi-step prediction, power feedback control is added on the DC side to increase the DC side’s reaction speed, eliminate the influence of uncertainty, and realise better dynamic performance. According to the simulation results, we can observe that the proposed method has good followability, can compensate for the harmonics of the power grid, reduces the harmonic content to less than 5%, and can balance the DC-side capacitor voltage.

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Hoe, Ong Kam, Agileswari K. Ramasamy, Lee Jun Yin, Renuga Verayiah, Marayati Binti Marsadek, and Muhammad Abdillah. "Hybrid Control of Grid-Feeding and Fuzzy Logic Fault Detection in Solving Voltage Dynamic Problem within the Malaysian Distribution Network." Energies 14, no. 12 (June 15, 2021): 3545. http://dx.doi.org/10.3390/en14123545.

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The stochastic behavior of PV together with high PV penetration have given rise to power quality concerns involving voltage dynamic issues such as undervoltage, overvoltage, sag and swell. To ensure the grid’s stability, various methods have been practiced such as a proper sizing of the grid lines and the installation of power quality compensation equipment. However, these measures often require high costs and high control complexity due to additional equipment being involved such as multiple transformers and inverters. Moreover, the current available reactive power compensation equipment has a lesser impact on distribution level networks. Therefore, this work proposes a hybrid control of grid-feeding mode and energy storage with Direct Current (DC) fault detection scheme utilizing fuzzy control to mitigate high PV penetration problems, PV intermittency and faults via active power compensation to maintain the system’s voltage within its nominal range. This hybrid control works on two mode of operations: strategic power dispatch by the grid-feeding mode to solve under and overvoltage caused by inconsistent PV generation. Meanwhile, the utilization of fuzzy control aims to solve PV intermittency and line faults. The novel hybrid control has proven its capability to solve voltage dynamic problems caused by high PV penetration, intermittency and faults in the network within a shorter timeframe.

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Luo, Ya Di, Jing Li, Pei Yu Jia, Jie Xu, Sen Li, and Jia Tong Du. "The Parallel Solving and Program Implementation Method of Large-Scale Power Flow Correction Equations." Applied Mechanics and Materials 556-562 (May 2014): 3809–13. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.3809.

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This paper present a parallel solving method of large-scale power flow correction equations and the program implementation based on the shared memory programming model OpenMP, which Improve the utilization rate the computer CPU resources and the computing speed. The method uses factor tables for solving the power flow equations. Combined the sparsity of correction equations coefficient matrix, the rows which can be do normalized simultaneously are grouped for doing the normalization and elimination operations in parallel. Meanwhile, use the row grouping information which is obtained during the factor table generation process to do parallel previous generation computing. Finally, the simulation for the actual power grid verified the validity and rationality of the method.

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Ju, Liwei, Zhongfu Tan, Huanhuan Li, Xiaobao Yu, and Huijuan Zhang. "Multiobjective Synergistic Scheduling Optimization Model for Wind Power and Plug-In Hybrid Electric Vehicles under Different Grid-Connected Modes." Mathematical Problems in Engineering 2014 (2014): 1–15. http://dx.doi.org/10.1155/2014/179583.

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In order to promote grid’s wind power absorptive capacity and to overcome the adverse impacts of wind power on the stable operation of power system, this paper establishes benefit contrastive analysis models of wind power and plug-in hybrid electric vehicles (PHEVs) under the optimization goal of minimum coal consumption and pollutant emission considering multigrid connected modes. Then, a two-step adaptive solving algorithm is put forward to get the optimal system operation scheme with the highest membership degree based on the improvedεconstraints method and fuzzy decision theory. Thirdly, the IEEE36 nodes 10-unit system is used as the simulation system. Finally, the sensitive analysis for PHEV’s grid connected number is made. The result shows the proposed algorithm is feasible and effective to solve the model. PHEV’s grid connection could achieve load shifting effect and promote wind power grid connection. Especially, the optimization goals reach the optimum in fully optimal charging mode. As PHEV’s number increases, both abandoned wind and thermal power generation cost would decrease and the peak and valley difference of load curve would gradually be reduced.

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Zhang, Bai Hua, Hai Feng Guo, Yong Xing Li, Man Chen, Yong Qi Li, and Jin Song Zhou. "Optimization of Smoothing Control in Hybrid Wind and Battery Energy Storage System." Advanced Materials Research 852 (January 2014): 703–7. http://dx.doi.org/10.4028/www.scientific.net/amr.852.703.

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In recent years, renewable energy technologies like wind power generation are developing very fast. However, due to the randomness and intermittency of wind, the integration of large-scale wind farm into grid will have negative impact on many aspects of the grid. An effective way to solve these problems is to install battery energy storage system (BESS) in a wind farm. In order to smooth the output power of wind farm, this paper established a mathematical model for solving optimization problems of hybrid wind and BESS system, solved it with modern interior point algorithm. Charge-discharge process of BESS is optimized using the result of wind power prediction. Sensitivity of constraints in the model is also analyzed and optimal design of output power and capacity of BESS can be obtained as a by-product.

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Kaltenbacher, Manfred, and Sebastian Floss. "Nonconforming Finite Elements Based on Nitsche-Type Mortaring for Inhomogeneous Wave Equation." Journal of Theoretical and Computational Acoustics 26, no. 03 (September 2018): 1850028. http://dx.doi.org/10.1142/s2591728518500287.

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We propose the nonconforming Finite Element (FE) method based on Nitsche-type mortaring for efficiently solving the inhomogeneous wave equation, where due to the change of material properties the wavelength in the subdomains strongly differs. Therewith, we gain the flexibility to choose for each subdomain an optimal grid. The proposed method fulfills the physical conditions along the nonconforming interfaces, namely the continuity of the acoustic pressure and the normal component of the acoustic particle velocity. We apply the nonconforming grid method to the computation of transmission loss (TL) of an expansion chamber utilizing micro-perforated panels (MPPs), which are modeled by a homogenization approach via a complex fluid. The results clearly demonstrate the superiority of the nonconforming FE method over the standard FE method concerning pre-processing, mesh generation flexibility and computational time.

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Dkhili, Nouha, David Salas, Julien Eynard, Stéphane Thil, and Stéphane Grieu. "Innovative Application of Model-Based Predictive Control for Low-Voltage Power Distribution Grids with Significant Distributed Generation." Energies 14, no. 6 (March 23, 2021): 1773. http://dx.doi.org/10.3390/en14061773.

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In past decades, the deployment of renewable-energy-based power generators, namely solar photovoltaic (PV) power generators, has been projected to cause a number of new difficulties in planning, monitoring, and control of power distribution grids. In this paper, a control scheme for flexible asset management is proposed with the aim of closing the gap between power supply and demand in a suburban low-voltage power distribution grid with significant penetration of solar PV power generation while respecting the different systems’ operational constraints, in addition to the voltage constraints prescribed by the French distribution grid operator (ENEDIS). The premise of the proposed strategy is the use of a model-based predictive control (MPC) scheme. The flexible assets used in the case study are a biogas plant and a water tower. The mixed-integer nonlinear programming (MINLP) setting due to the water tower ON/OFF controller greatly increases the computational complexity of the optimisation problem. Thus, one of the contributions of the paper is a new formulation that solves the MINLP problem as a smooth continuous one without having recourse to relaxation. To determine the most adequate size for the proposed scheme’s sliding window, a sensitivity analysis is carried out. Then, results given by the scheme using the previously determined window size are analysed and compared to two reference strategies based on a relaxed problem formulation: a single optimisation yielding a weekly operation planning and a MPC scheme. The proposed problem formulation proves effective in terms of performance and maintenance of acceptable computational complexity. For the chosen sliding window, the control scheme drives the power supply/demand gap down from the initial one up to 38%.

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Alexandrov, V., A. Buyanov, L. Markova, and M. Sivers. "Researching Digital Methods of Generation Signals of Hydroacoustic Phased Antenna Grids." Proceedings of Telecommunication Universities 7, no. 1 (March 31, 2021): 42–53. http://dx.doi.org/10.31854/1813-324x-2021-7-1-42-53.

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Solving tasks of creation, correction and parametric control of signals excitation hydroacoustic phased antenna grids is actual problem of creating multichannel generated devices, based on switch-mode amplifiers with pulse-width modulation. In this article were reviewed correction methods output signals of hydroacoustic transmission paths, periodic pulse sequence creation and parametric voltage level control of excitation channels of phased antenna grid with abrupt decrease impedance of hydroacoustic converters. Was shown the perspective implementation digital technologies for improvement parameters modes of hydrolocation with deterministic library of signals. Presented digital control methods of output signals in hydroacoustic transmission paths are characterized by scientific novelty and originality of the proposed technical decisions.

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Utomo, Oscar, Muditha Abeysekera, and Carlos E. Ugalde-Loo. "Optimal Operation of a Hydrogen Storage and Fuel Cell Coupled Integrated Energy System." Sustainability 13, no. 6 (March 22, 2021): 3525. http://dx.doi.org/10.3390/su13063525.

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Integrated energy systems have become an area of interest as with growing energy demand globally, means of producing sustainable energy from flexible sources is key to meet future energy demands while keeping carbon emissions low. Hydrogen is a potential solution for providing flexibility in the future energy mix as it does not emit harmful gases when used as an energy source. In this paper, an integrated energy system including hydrogen as an energy vector and hydrogen storage is studied. The system is used to assess the behaviour of a hydrogen production and storage system under different renewable energy generation profiles. Two case studies are considered: a high renewable energy generation scenario and a low renewable energy generation scenario. These provide an understanding of how different levels of renewable penetration may affect the operation of an electrolyser and a fuel cell against an electricity import/export pricing regime. The mathematical model of the system under study is represented using the energy hub approach, with system optimisation through linear programming conducted via MATLAB to minimise the total operational cost. The work undertaken showcases the unique interactions the fuel cell has with the hydrogen storage system in terms of minimising grid electricity import and exporting stored hydrogen as electricity back to the grid when export prices are competitive.

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Hussan, Md Reyaz, Adil Sarwar, Marif Daula Siddique, Saad Mekhilef, Shafiq Ahmad, Mohamed Sharaf, Mazen Zaindin, and Muhammad Firdausi. "A Novel Switched-Capacitor Multilevel Inverter Topology for Energy Storage and Smart Grid Applications." Electronics 9, no. 10 (October 16, 2020): 1703. http://dx.doi.org/10.3390/electronics9101703.

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The recent advancement in the application of the internet of things in the smart grid has led to an industrial revolution in the power industry. The Industry 4.0 revolution has already set in, allowing computers to interact for an efficient and intelligent approach in solving smart grid issues. multilevel inverters (MLIs) are an integral part of the smart grid system for integrating the distributed generation sources and storage energy systems into the smart grid. It attracted attention in industrial applications as they can handle high power and high voltage with an inherent feature of superior output voltage waveform quality. Moreover, its variant, the switched-capacitor MLI (SCMLI), has the added benefit of lesser DC supply requirement. In this paper, a switched-capacitor multilevel inverter topology has been proposed, which can operate in symmetric and asymmetric mode. The proposed SCMLI generate thirteen and thirty-one level output voltages for symmetric and asymmetric selection of DC voltage sources, respectively. The proposed SCMLI has a smaller number of switching devices for a given output voltage level as compared to other recently proposed topologies. A thorough comparison is presented with the recently proposed topologies on several parameters, including cost function. To validate the proposed topology, symmetric and asymmetric cases were simulated using Matlab® 2018a and the results were verified using an experimental hardware setup.

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Bagade, Pramodkumar M., Yogesh G. Bhumkar, and Tapan K. Sengupta. "An improved orthogonal grid generation method for solving flows past highly cambered aerofoils with and without roughness elements." Computers & Fluids 103 (November 2014): 275–89. http://dx.doi.org/10.1016/j.compfluid.2014.07.031.

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Mohebbi, Farzad, Ben Evans, and Mathieu Sellier. "On the Kutta Condition in Compressible Flow over Isolated Airfoils." Fluids 4, no. 2 (June 1, 2019): 102. http://dx.doi.org/10.3390/fluids4020102.

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This paper presents a novel and accurate method to implement the Kutta condition in solving subsonic (subcritical) inviscid isentropic compressible flow over isolated airfoils using the stream function equation. The proposed method relies on body-fitted grid generation and solving the stream function equation for compressible flows in computational domain using finite-difference method. An expression is derived for implementing the Kutta condition for the airfoils with both finite angles and cusped trailing edges. A comparison of the results obtained from the proposed numerical method and the results from experimental and other numerical methods reveals that they are in excellent agreement, which confirms the accuracy and correctness of the proposed method.

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Kurtinaitis, A., A. Dementjev, and F. Ivanauskas. "Modeling of Pulse Propagation Factor Changes in Type II Second Harmonic Generation." Nonlinear Analysis: Modelling and Control 6, no. 2 (December 5, 2001): 51–69. http://dx.doi.org/10.15388/na.2001.6.1.15215.

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We describe the simulations of the second harmonic generation of ultrashort laser pulses by numerically solving a system of wave propagation equations. The equations are solved by using a split-step method in twodimensional cyllindrically symmetric space and time coordinates. The diffraction part of a solution uses the Hopscotch type finite-difference scheme on a regular grid. The transport part is solved by using the cubic spline approximation. The obtained numerical results satisfactorily respect energy conservation constraints. The algorithm and program developed make it possible to optimize the process of the second harmonics generation and to identify the conditions where sufficiently high degree of the pulse compression with a relatively low degradation of their quality is achieved.

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Oodo, Stephen, and Felix S. Owolabi. "Application of a Genetic Algorithm for Improving Voltage Profile with Distributed Generation." European Journal of Engineering Research and Science 4, no. 1 (January 24, 2019): 64–68. http://dx.doi.org/10.24018/ejers.2019.4.1.1063.

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The purpose of a power grid is to transfer electrical energy from the production to the consumption, while maintaining an acceptable reliability and voltage quality for all customers. This research paper present the integration of generation based on Biogas power renewable energy source to the Distribution network and how it stabilizes the network by normalizing the fluctuating voltage at the distribution end of power system. A Genetic Algorithm model was performed and evaluation of the impact of the DG by stimulating the developed model in the system. A mathematical formulation and optimization algorithm was performed using the MATLAB/Simulink program. The results obtained were correction of the faulty buses voltages and stable power supply which is 25% better than the conventional one. It was concluded that the implementation of the optimisation technique has improved the energy efficiency of the distribution network.

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Hong, June S., and Mihui Kim. "Game-Theory-Based Approach for Energy Routing in a Smart Grid Network." Journal of Computer Networks and Communications 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/4761720.

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Small power plants and buildings with renewable power generation capability have recently been added to traditional central power plants. Through these facilities, prosumers appear to have a concurrent role in both energy production and consumption. Based on bidirectional power transfers by large numbers of prosumers, a smart microgrid has become an important factor in efficiently controlling the microgrids used in power markets and in conducting effective power trades among grids. In this paper, we present an approach utilizing the game theory for effective and efficient energy routing, which is a novel and challenging procedure for a smart microgrid network. First, we propose strategies for choosing the desired transaction price for both electricity surpluses and shortages to maximize profits through energy transactions. An optimization scheme is utilized to search for an energy route with minimum cost using the solving method used in a traditional transportation problem by treating the sale and purchase quantities as transportation supply and demand, respectively. To evaluate the effect of the proposed decision strategies, we simulated our mechanism, and the results proved that our mechanism yields results pursued by each strategy. Our proposed strategies will contribute to spreading a smart microgrid for enhancing the utilization of microgrids.

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Molina, Alexander, Oscar Danilo Montoya, and Walter Gil-González. "Exact minimization of the energy losses and the CO2 emissions in isolated DC distribution networks using PV sources." DYNA 88, no. 217 (May 20, 2021): 178–84. http://dx.doi.org/10.15446/dyna.v88n217.93099.

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This paper addresses the optimal location and sizing of photovoltaic (PV) sources in isolated direct current (DC) electrical networks, considering time-varying load and renewable generation curves. The mathematical formulation of this problem corresponds to mixed-integer nonlinear programming (MINLP), which is reformulated via mixed-integer convex optimization: This ensures the global optimum solving the resulting optimization model via branch & bound and interior-point methods. The main idea of including PV sources in the DC grid is to minimize the daily energy losses and greenhouse emissions produced by diesel generators in isolated areas. The GAMS package is employed to solve the MINLP model, using mixed and integer variables; also, the CVX and MOSEK solvers are used to obtain solutions from the proposed mixed-integer convex model in the MATLAB. Numerical results demonstrate important reductions in the daily energy losses and the harmful gas emissions when PV sources are optimally integrated into DC grid.

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Abdulgalil, Mohammed Atta, Muhammad Khalid, and Fahad Alismail. "Optimal Sizing of Battery Energy Storage for a Grid-Connected Microgrid Subjected to Wind Uncertainties." Energies 12, no. 12 (June 23, 2019): 2412. http://dx.doi.org/10.3390/en12122412.

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In this paper, based on stochastic optimization methods, a technique for optimal sizing of battery energy storage systems (BESSs) under wind uncertainties is provided. Due to considerably greater penetration of renewable energy sources, BESSs are becoming vital elements in microgrids. Integrating renewable energy sources in a power system together with a BESS enhances the efficiency of the power system by enhancing its accessibility and decreasing its operating and maintenance costs. Furthermore, the microgrid-connected BESS should be optimally sized to provide the required energy and minimize total investment and operation expenses. A constrained optimization problem is solved using an optimization technique to optimize a storage system. This problem of optimization may be deterministic or probabilistic. In case of optimizing the size of a BESS connected to a system containing renewable energy sources, solving a probabilistic optimization problem is more effective because it is not possible to accurately determine the forecast of their output power. In this paper, using the stochastic programming technique to discover the optimum size of a BESS to connect to a grid-connected microgrid comprising wind power generation, a probabilistic optimization problem is solved. A comparison is then produced to demonstrate that solving the problem using stochastic programming provides better outcomes and to demonstrate that the reliability of the microgrid improves after it is connected to a storage system. The simulation findings demonstrate the efficacy of the optimum sizing methodology proposed.

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Niemann, S., B. Kolesnikov, H. Lohse-Busch, C. Hühne, O. M. Querin, V. V. Toropov, and D. Liu. "The use of topology optimisation in the conceptual design of next generation lattice composite aircraft fuselage structures." Aeronautical Journal 117, no. 1197 (November 2013): 1139–54. http://dx.doi.org/10.1017/s0001924000008745.

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Abstract Conventional commercial aircraft fuselages use all-aluminium semi-monocoque structures where the skin carries the external loads, the internal fuselage pressurisation and is strengthen using frames and stringers. Environmental and economic issues force aircraft designers to minimise weight and costs to keep air transport competitive and safe. But as metal designs have reached a high degree of perfection, extraordinary weight and cost savings are unlikely in the future. Carbon composite materials combined with lattice structures and the use of topology optimisation have the potential to offer such weight reductions. The EU FP7 project Advanced Lattice Structures for Composite Airframes (ALaSCA) was started to investigate this. This article present some of this research which has now led to the development of a new airframe concept which consists of: a load carrying inner skin; transverse frames; CFRP-metal hybrid stiffeners helically arranged in a grid configuration; insulating foam and an additional aerodynamic outer skin.

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Journal articles on the topic 'Grid generation; Grid solving; Optimisation'

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