The development of the smart grid promotes the rapid development of distributed generation (DG), while the intermittent nature of DG and the growing demand for electricity make it difficult for the grid to maintain th...
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ISBN:
(纸本)9781665434515
The development of the smart grid promotes the rapid development of distributed generation (DG), while the intermittent nature of DG and the growing demand for electricity make it difficult for the grid to maintain the reliability and stability of the grid. Moreover, the time interval between peak demand of electricity usually differs from the peak supply provided by DG, which creates a mismatch between supply and demand. An energy storage system (ESS) can be an effective solution to improve the self-consumption of electricity generated by DG. In this paper, an optimization strategy of household energy management based on DG and ESS is proposed, which makes full use of the rechargeable characteristics of ESS and EV to improve the economy and flexibility of the system in the case of uncertain output prediction of DG. The objective is to minimize the cost of electricity consumption and user comfort. The actual situation of the users is taken into account, as well as the integration of renewable energy, energy storage, demand response, and other new technologies in the smart grid. Finally, the effectiveness of the proposed model and algorithm is verified by multi-scenario analysis.
The increasing share of generation based on renewable energy sources and the resulting demand for transport capacities make grid expansion necessary. In order to conduct structural measures on the transmission grid, i...
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ISBN:
(纸本)9781665443890
The increasing share of generation based on renewable energy sources and the resulting demand for transport capacities make grid expansion necessary. In order to conduct structural measures on the transmission grid, in many cases, the corresponding transmission lines need to be shut down. Measures include grid expansion and maintenance, with the completion of expansion measures changing the topology of the grid and allowing additional operational degrees of freedom. This contribution presents a novel approach based on mixed-integer linear programming to scheduling grid expansion and maintenance measures while optimizing grid operation. The method is applied to a synthetic 120-bus test system and the results show that suitable schedules can be obtained.
This paper considers a distributed production network scheduling that involves heterogeneous factories with the parallel machine. Although, each factory has its own local customers as a production agent, for better lo...
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This paper considers a distributed production network scheduling that involves heterogeneous factories with the parallel machine. Although, each factory has its own local customers as a production agent, for better load balancing of machines in the production network, the jobs can transfer among factories. In order to make the problem more realistic, in addition to considering the ability of factories in processing of jobs, the capacity constraints of factories are also included in the scheduling. The aim of this paper is to maximize the profits of jobs such that each job is assigned to precisely one factory subject to their deadlines. To solve this problem, based on the decomposition algorithm, for the first time, an efficient decomposition-based branch and cut algorithm is designed. In this regard, first, the problem is formulated as a mixed-integerlinear program (MILP), then using the Benders decomposition structure and after reformulating as an assignment subproblem and single factory scheduling subproblems, a branch and cut algorithm is proposed. Finally, the obtained results of the proposed algorithm, the original MILP, and non-cooperative local scheduling, all solved by CPLEX, are compared.
LNG (Liquefied Natural Gas) provides a viable option to comply with emission control measures as an alternative marine fuel. Supply chain optimization is critical for LNG bunkering development in the mar-itime context...
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LNG (Liquefied Natural Gas) provides a viable option to comply with emission control measures as an alternative marine fuel. Supply chain optimization is critical for LNG bunkering development in the mar-itime context as it requires high capital-expenditure. This study proposes a model for optimizing the ship-to-ship LNG bunkering supply chain. The related problem is defined as a Multiple Period Maritime Fleet Size and Routing Problem. The proposed mathematical model has been solved for various demand scenarios obtained by multiple regression and forecasting as a case study of ship-to-ship LNG bunker deliveries in Turkey. The model presents an optimal solution as a tactical and strategic decision-making tool, finds the number and size of the LNG bunker barges and the optimum allocation of the barges and the distribution network within a ship-to-ship bunkering framework. Moreover, it provides a commercial framework for shipowners and suppliers by determining the breakeven point for investment decisions.(c) 2022 Elsevier Ltd. All rights reserved.
A challenge in planning the operations of multisite production networks is the need to simultaneously balance production across sites while satisfying customers demand and keeping customer service levels high and over...
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A challenge in planning the operations of multisite production networks is the need to simultaneously balance production across sites while satisfying customers demand and keeping customer service levels high and overall costs low. Accordingly, we present a planning approach for the simultaneous optimization of production and distribution operations. Specifically, we consider a regional Argon supply chain, comprised of multiple production sites and customers, in which liquid Argon is distributed through tanker trucks under cryogenic conditions. The proposed approach first generates detailed routes and then uses these routes in an integrated model to fully optimize production and distribution. Using a series of case studies, based on industrially inspired data, we show that the proposed approach leads to high quality results for regional networks of real-world sizes.(c) 2022 Elsevier Ltd. All rights reserved.
Even though many studies have been deployed to determine the optimal planning and operation of microgrids, limited research was discussed to determine the optimal microgrids' geographical boundaries. This paper pr...
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Even though many studies have been deployed to determine the optimal planning and operation of microgrids, limited research was discussed to determine the optimal microgrids' geographical boundaries. This paper proposes a zonal-based optimal microgrid identification model aiming at identifying the optimal microgrids topology in the current distribution systems through zoning the network into several clusters. In addition, the proposed model was developed as a mixed-integer linear programming (MILP) problem that identifies the optimal capacity and location of installing distributed energy resources (DERs), including but not limited to renewable energy resources and Battery Energy Storage Systems (BESS), within the determined microgrid's boundaries. Moreover, it investigates the impact of incorporating the BESS in boosting the DERs' penetration on the optimal centralized microgrid. Numerical simulations on the IEEE-33 bus test system demonstrate the features and effectiveness of the proposed model on identifying the optimal microgrid geographical boundaries on current distribution grids as well as its capability on defining the optimal sizes and locations of installing DERs within the microgrid's zonal area.
In this paper, we address the pickup and delivery problem with time windows (PDP-TW) and heterogenous vehicles for minimisation of total tardiness by learning heuristics from a given set of solutions. In order to extr...
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In this paper, we address the pickup and delivery problem with time windows (PDP-TW) and heterogenous vehicles for minimisation of total tardiness by learning heuristics from a given set of solutions. In order to extract scalable heuristics from optimal or best feasible solutions, we propose a machine-learning (ML)-based approach called ENSIGHT (Evolutionary Neural network with Scalable Information for Generation of Heuristics for Transportation). ENSIGHT consists of three phases: solution generation, interpretation of solutions, and improvement of heuristics by an evolutionary neural network (ENN). First, a set of optimal or best feasible solutions for the training set of problem instances is acquired by using the proposed mathematical model. Second, as for the process interpreting those solutions, an approach for transforming them into training data by way of scalable input attributes as well as output discretisation is followed. Third, the ENN improves the learned heuristics by an evolutionary parameter optimisation process for minimization of total tardiness. To verify the performance of the proposed ENSIGHT, we conducted experiments and the results of which showed that it outperforms other ML techniques and the current dispatching rules (DRs). Moreover, the approach was demonstrated to be effective in learning scalable heuristics based on combined scalable inputs and discretisation as well as an evolutionary improvement process.
Discrete sizing and topology optimization of truss structures subject to stress and displacement constraints has been formulated as a mixed-integer linear programming (MILP) problem. The computation time to solve a MI...
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Discrete sizing and topology optimization of truss structures subject to stress and displacement constraints has been formulated as a mixed-integer linear programming (MILP) problem. The computation time to solve a MILP problem to global optimality via a branch-and-cut solver highly depends on the problem size, the choice of design variables, and the quality of optimization constraint formulations. This paper presents a new formulation for discrete sizing and topology optimization of truss structures, which is benchmarked against two well-known existing formulations. Benchmarking is carried out through case studies to evaluate the influence of the number of structural members, candidate cross sections, load cases, and design constraints (e.g., stress and displacement limits) on computational performance. Results show that one of the existing formulations performs significantly worse than all other formulations. In most cases, the new formulation proposed in this work performs best to obtain near-optimal solutions and verify global optimality in the shortest computation time.
This paper develops an optimization framework for scheduling charging and dispatch of regenerative braking energy (RBE) generated by an electric train system fed by a reversible substation. The mixed-integerlinear pr...
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ISBN:
(纸本)9781728186481
This paper develops an optimization framework for scheduling charging and dispatch of regenerative braking energy (RBE) generated by an electric train system fed by a reversible substation. The mixed-integer linear programming model presented seeks to maximize the RBE retained in the system within its physical constraints, demonstrating the potential for the storage of RBE for use in grid services and resilience applications such as outage response and security-constrained dispatch. Daily and yearly time series analyses are used to showcase energy cost reductions of up to 20% per year, and decreased reliance on power from the grid, leading to reduced lifecycle operation emissions. The model is calibrated on real LMP data from the New England Independent System Operator. Furthermore, the proposed modeling approach is able to capture energy consumption differences associated with selected operational and design parameters, and thus is applicable for policy or project-level analyses to motivate transit electrification decisions.
In this paper, we consider the problem of maximizing user coverage for 5G/6G wireless communication networks subject to facility location and radial distance constraints. For this purpose, we propose two novel mixed-i...
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ISBN:
(纸本)9781665442251
In this paper, we consider the problem of maximizing user coverage for 5G/6G wireless communication networks subject to facility location and radial distance constraints. For this purpose, we propose two novel mixed-integer linear programming models which are constructed based on a classical combinatorial optimization problem referred to as the p-Median problem in the literature. In the classical p-Median problem, one seeks to find a subset of p facilities in order to assign users to them while minimizing the total distance costs between users and facilities. The novelty of our proposed models is the consideration of non-overlapping radial distance constraints between antennas (facilities). In particular, our first model maximizes the total number of users. Whilst the second one includes in the objective function the maximization of users and the minimization of the number of antennas to be activated. So far we solve instances with up to 100 antennas and 1000 users with the Gurobi solver. Our preliminary numerical results indicate that the first model is harder to solve to global optimality than the second one. The numerical results obtained also show that the increase in the number of radius allowed provides more flexibility and accuracy to the model, although at a higher computational cost. Finally, we highlight that the proposed models can be used for future developments of 5G/6G networks in order to improve coverage.
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