This paper introduces a hierarchical control strategy for energy management in a hybrid AC/DC microgrid, emphasizing the influence of electric vehicle (EV) charging patterns. The power flow and standard operating cond...
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Driven by ambitious renewable portfolio standards, large-scale inclusion of variable energy resources (such as wind and solar) are expected to introduce unprecedented levels of uncertainty into power systems operation...
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Driven by ambitious renewable portfolio standards, large-scale inclusion of variable energy resources (such as wind and solar) are expected to introduce unprecedented levels of uncertainty into power systems operations. The current practice of operations planning with deterministic optimization models may be ill-suited for a future with abundant uncertainty. To overcome the potential reliability and economic challenges, we present a stochastic hierarchical planning (SHP) framework for power systems coordinated by a centralized planner. This framework captures operations at day-ahead, short-term and hour-ahead timescales, along with the interactions between the stochastic processes and decisions. In contrast to earlier studies where stochastic optimization of individual problems (e.g., unit commitment, economic dispatch) have been studied, this paper studies an integrated framework of planning under uncertainty , where stochastic optimization models are stitched together in a hierarchical setting, which parallels the deterministic hierarchical planning approach that is widely adopted in the power industry. Our experiments, based on the NREL-118 dataset, reveal that under high renewable integration, significant operational improvements can be expected by transitioning to the SHP paradigm. In particular, the computational results show that significant improvements can be achieved in several metrics, including system reliability, environmental sustainability, and system economics, solely by making a strategic choice to adopt the new SHP paradigm. (c) 2022 Elsevier B.V. All rights reserved.
This paper proposes a novelmodeling framework and decomposition-based solution strategy combining stochastic programming (SP) and robust optimization (RO) to dealwith multiplex uncertainties in coordinated mid- and lo...
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This paper proposes a novelmodeling framework and decomposition-based solution strategy combining stochastic programming (SP) and robust optimization (RO) to dealwith multiplex uncertainties in coordinated mid- and long-term power system planning. The problem is formulated as a multi-year generation and transmission planning problem from an independent system operator (ISO)'s perspective to minimize both expansion and operational costs under binary and continuous uncertainties, i.e., system component contingency and load/generation variation. N-k contingencies are captured in RO using the reformulated contingency criteria, while the load/generation uncertainty is considered in SP embedded with RO using operating scenarios generated from the historical data with spatiotemporal correlations. The original hybrid model is highly intractable, but the intractability can be relieved by the proposed decomposition strategy based on the column-and-constraint generation and L-shaped algorithms. We apply our model to perform long-term system planning under extremely high renewable penetration and investigate the case of 100% renewables in long-term planning. Numerical experiments on multi-scale test systems verify the efficacy of the proposed approach.
Regarding the railway infrastructures, planning for track maintenance is a challenging task given the coordination required between train traffic and maintenance operations. In this paper, using stochastic mathematica...
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Regarding the railway infrastructures, planning for track maintenance is a challenging task given the coordination required between train traffic and maintenance operations. In this paper, using stochastic mathematical programming, we have investigated the simultaneous scheduling of trains and operations for a single-track line to minimise both the travel time of trains and maintenance duration. The uncertainty in the blockage duration of the track is considered in the model to reduce the impact of unexpected delays in maintenance operations. The proposed model also considers the practical aspects, which have been less addressed in previous studies regarding track maintenance. We reformulated the stochastic problem as its deterministic equivalent to facilitate solutions for realistic sizes. The computational result obtained for a real-world track shows that the model can efficiently find simultaneous scheduling of trains and operations and suggest optimal blockage duration at different confidence levels. The impact of timetable comparison on the blockage duration for a heavily utilised line has also been evaluated.
Since modern cyber-physical power systems are vulnerable to coordinated wide-area cyber attacks, it is necessary to mitigate the potential risk as much as possible. At the planning stage, the defender can utilize soft...
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Since modern cyber-physical power systems are vulnerable to coordinated wide-area cyber attacks, it is necessary to mitigate the potential risk as much as possible. At the planning stage, the defender can utilize software diversity, which is a common phenomenon that the cyber software of different substations comes from different competing vendors. Therefore, different kinds of software may not be exposed to the same zero-day security loophole, preventing the attacker from taking charge of multiple substations at the same time. In this paper, the optimal scheme of software deployment considering long-term risk mitigation is studied. Firstly, the framework of diversity-based cyber defense against malicious attacks is formulated. Secondly, the risk index based on representative attack patterns is constructed, which is the objective to be minimized. Thirdly, considering that the deployment scheme is long-term stable while the operating mode varies with time, we construct a multiobjective nonlinear stochastic programming to mitigate the average risk of operating modes. Then the optimization problem is solved by the multiobjective genetic algorithm. Lastly, results of the IEEE 39-node CPPS and and the Virtual European Grid demonstrate that the proposed method can considerably reduce the attack risk.
This paper focuses on a real-time response system supported by AI developed to improve national emergency readiness and disaster response. The proposed system includes decision support for disaster response through re...
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To effectively decrease emissions and pollution emitted by equipment in container ports, many ports began to update equipment using diesel fuels to achieve the aim of green ports. This paper studies an internal truck ...
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To effectively decrease emissions and pollution emitted by equipment in container ports, many ports began to update equipment using diesel fuels to achieve the aim of green ports. This paper studies an internal truck renewal problem in container ports and proposes a two-stage stochastic programming model to optimally determine internal truck composition optimization adjustment including three renewal modes, i.e. purchasing, retrofitting, and chartering. An exact solution procedure based on Benders decomposition accelerating by Pareto-optimal cuts is developed for the proposed model. Given the problem background of Shanghai Yangshan Deep Water Port, comprehensive computational experiments are carried out to verify the effectiveness of the proposed mathematical model and the performance of the solution approach. According to the numerical experiments, some suggestions for the management of renewing internal trucks in green ports are summarized at the end of the paper.
Making rapid decisions in intervention resource planning is crucial for mitigating morbidity, mortality, and costs to the societies during epidemic outbreaks. This study presents a data-driven optimization approach fo...
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Making rapid decisions in intervention resource planning is crucial for mitigating morbidity, mortality, and costs to the societies during epidemic outbreaks. This study presents a data-driven optimization approach for multiperiod resources planning, based on a sequential decision framework, considering up-to-date information and uncertainty in the spread of epidemics. In this method, a new (SEIHRD)-H-3-R-2 spread model is constructed to generate the most potential scenarios of an epidemic, based on all the historical information, and risk-averse stochastic programming was proposed to arrive at an optimal resource planning solution. The data-based numerical experiments demonstrate that our approach could control the epidemic by reducing the infected cases and deaths with similar or fewer resources than in the reality. In addition, we also find that the risk-averse design of the objective was able to take a steadier approach to resource planning helped avoid large fluctuations in resource allocations compared to a risk-neutral design. The other insight obtained from these experiments was that a moderate decision interval along with a planning horizon, which is slightly larger than the decision interval, would be a good choice for the sequential planning problem.
This article presents a framework to determine driving style and design a driver steering model considering driver characteristics. First, principal component analysis (PCA) and K-means clustering are utilized to clas...
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This article presents a framework to determine driving style and design a driver steering model considering driver characteristics. First, principal component analysis (PCA) and K-means clustering are utilized to classify 30 participants into cautious, moderate, and aggressive drivers. Subsequently, a generic steering model is established based on the model predictive control method. Thereafter, the maximum lateral acceleration is extracted as a crucial indicator to represent driver characteristics, and it is calibrated through probabilistic models using the dataset, which consists of the classified drivers. Besides, point estimation model and interval estimation model are leveraged to determine driving style and adjust constraints in the stochastic programming-based steering model. Finally, simulation experiments present the variations of actual output trajectories between the aggressive drivers and the cautious drivers.
The electricity market is an economic environment of the power system in order to buy and sell energy in the presence of different players. One of the most effective part of electricity market is retail electricity ma...
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The electricity market is an economic environment of the power system in order to buy and sell energy in the presence of different players. One of the most effective part of electricity market is retail electricity market. Electricity price in the retail electricity market has a different rate for various types of customers. So, various retail prices are generally settled for different customers in the retail market. In power market, retailers purchase large volume of energy from power producers and sell it to customers. This paper from the retailer prospective while to encourage the customer to participate in priced-based demand response (DR) programs, proposes the nonlinear model by considering uncertainties in pool market and demand elasticity to decrease the energy procurement in hours with high pool *** the formulation of suggested stochastic model. Risk measurement of the proposed model is obtained by Value at Risk and Conditional Value at Risk. By applying the proposed model, electricity retailer will be capable to choose different risk-based strategies. The proposed model will lead to optimal management and decision-making of the retailer in purchasing from bilateral contracts and the pool market. Therefore, based on the suggested economic approach, the proposed model by considering the DR program reduces energy consumption during peak hours, which facilitates the supply of electricity to customers during these hours. Finally the case study is implemented in GAMS software and solved Via MINOS solver to observe the effectiveness and validation of the suggested model.
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