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1.
In the competitive electricity market it becomes very much important to give special consideration for development of renewable energy sources (RESs) due to environmental and other social problems related with conventional generations. So this paper presents an optimal model of congestion management with special emphasis for promotion of RES in competitive electricity market. This paper presents a generalized optimal model of congestion management for deregulated power sector that dispatches the pool in combination with privately negotiated bilateral and multilateral contracts while maximizing social benefit. This model determines the locational marginal pricing (LMP) based on marginal cost theory. It also determines the size of non-firm transactions as well as pool demand and generations. Both firms as well as non-firm transactions are considered in this model. The proposed model has been applied to IEEE-30 bus test system with addition of some RES for analysis of the proposed model. The RES supplies its power to load either through the firm transaction or through power pool. The power from RES is not subjected to any curtailment in proposed model of congestion management. 相似文献
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This paper examines a California-based microgrid's decision to invest in a distributed generation (DG) unit fuelled by natural gas. While the long-term natural gas generation cost is stochastic, we initially assume that the microgrid may purchase electricity at a fixed retail rate from its utility. Using the real options approach, we find a natural gas generation cost threshold that triggers DG investment. Furthermore, the consideration of operational flexibility by the microgrid increases DG investment, while the option to disconnect from the utility is not attractive. By allowing the electricity price to be stochastic, we next determine an investment threshold boundary and find that high electricity price volatility relative to that of natural gas generation cost delays investment while simultaneously increasing the value of the investment. We conclude by using this result to find the implicit option value of the DG unit when two sources of uncertainty exist. 相似文献
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Before new renewable generators can be connected to the electricity network, it is necessary to carefully evaluate the impact they will have. Firm connection agreements are based on snapshot assessments of the worst-case situation of maximum generation and minimum demand, which restrict renewable capacities despite infrequent occurrence. This work describes how time series of several renewable generation technologies together with demand can be applied to examine the opportunities and challenges offered by non-firm generation connections. It applies optimal power flow to extract maximum energy from available renewable resources while using curtailment of generation to maintain the network within thermal and voltage limits. By way of a case study of potential wind, wave and tidal current development in the Orkney Islands, Scotland, the analysis provides estimates for the degree of curtailment and consequent economic impact a renewable generator operating under non-firm connection may experience. The methods described provide a first-level analysis that could facilitate appraisal of non-firm connections at the planning stage by estimating the consequences of concurrent generation and demand as well as the frequency and duration of necessary curtailments. 相似文献
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Increasing connections for distributed generation (DG), and in particular, for wind generation, are being sought in power systems across the world. These increased applications present a significant challenge to the existing connection policies of distribution network operators. In particular, nonfirm access to the network has been proposed as a method to increase the penetration of DG. The impact of the connection policies arising from nonfirm access are investigated in detail here. The Irish system is used as a case study, and with reference to the available energy resource and network parameters, the costs and benefits of DG are determined under a number of planning policies. The costs and benefits assessed include connection and cycling costs along with emissions, capacity value, and fuel bill saving. It is shown that a significant increase in the net benefits of DG is gained if the appropriate connection policy is utilized from the outset, and conversely, significant costs are incurred if ad hoc policies are employed. Furthermore, it is shown that nonfirm access has the scope to facilitate a significant extra amount of DG capacity 相似文献
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In 2006, there is 8.5% distributed generation (DG) in Turkey which are generation units connected to the low and medium voltage distribution network. Out of this, 56% is industrial combined heat and power production (CHP) and 20% are renewables (RES-E), mainly runoff small scale hydro. Various technical and economical barriers have kept the DG share relatively low. This paper assesses how Turkey could increase the DG share. The methodology employed in this paper consist of a survey of the literature and legislation, combined with interviews with regulators, transmission and distribution system operators. Scenarios for DG are developed, barriers to increase the DG share are identified, DG and central generation (CG) are compared economically and regulatory measures are identified. The addition of long-run marginal transmission costs to the investment cost of new power generation units could close the long-run marginal cost difference between DG and CG. However, the share of DG is likely to stay low unless regulatory measures are taken. Moreover, a specific policy and regulation on DG is needed, the distribution grid needs strengthening, local dispatch centres need to become active and RES-E limits are needed for Turkey. 相似文献
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A first-order cost analysis of Photovoltaics power generation and DG power generation for urban emergency load is presented. Six years field data of two DG sets installed at IIT, Delhi for emergency load have been thoroughly analysed to find out the requirements for such power generation model.The unit cost of emergency load energy is calculated using different parameters. These are the interest rate of commercial loan at present value of Indian market, IREDA loan facility to promote PV, the depreciation cost, operation and maintenance cost of PV and DG sets, and fuel cost of DG set. It is found that the unit cost of PV electricity is cheaper or comparable with that from DG power at present market price. 相似文献
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Recently, microgrids have attracted considerable attention as a high-quality and reliable source of electricity. In this work energy management in microgrids is addressed in light of economic and environmental restrictions through (a) development of an operational strategy for energy management in microgrids and (b) determination of type and capacity of distributed generation (DG) sources as well as the capacity of storage devices (SD) based on optimization. Net present value is used as an economic indicator for justification of investment in microgrids. The proposed NPV-based objective function accounts for the expenses including the initial investment costs, operational strategy costs, purchase of electricity from the utility, maintenance and operational costs, as well as revenues including those associated with reduction in non-delivered energy, the credit for reduction in levels of environmental pollution, and sales of electricity back to the utility. The optimal solution maximizing the objective function is obtained using a hybrid optimization method which combines the quadratic programming (QP) and the particle swarm optimization (PSO) algorithms to determine the optimum capacity of the sources as well as the appropriate operational strategy for the microgrid. The fuzzy set theory is employed to account for the uncertainties associated with electrical power price. Application of the proposed method under different operational scenarios serves to demonstrate the efficiency of the proposed scheme. 相似文献
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There is renewed interest in distributed generation (DG). This paper reviews the different technological options available for DG, their current status and evaluates them based on the cost of generation and future potential in India. The non-renewable options considered are internal combustion engines fuelled by diesel, natural gas and microturbines and fuel cells fired by natural gas. The renewable technologies considered are wind, solar photovoltaic, biomass gasification and bagasse cogeneration. The cost of generation is dependent on the load factor and the discount rate. Gas engines and Bagasse based cogeneration are found to be the most cost effective DG options while wind and biomass gasifier fired engines are viable under certain conditions. PEM Fuel cells and micro turbines based on natural gas need a few demonstrations projects and cost reductions before becoming viable. A strategy involving pilot projects, tracking of costs and dissemination of information is likely to result in DG meeting 10% of India's power needs by 2012. 相似文献
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Droop control is a key strategy for operating islanded microgrid systems. The droop settings of the different distributed generation (DG) units in an islanded microgrid determine the operational characteristics of the island. This paper presents an algorithm for choosing the optimal droop parameters for islanded microgrids with wind generation in order to minimize the overall island generation costs in the absence of a microgrid central controller (MGCC). A detailed microgrid model is adopted to reflect the special features and operational characteristics of droop controlled islanded microgrid systems. The proposed problem formulation considers the power flow constraints, voltage and frequency regulation constraints, line capacity constraints and unit capacity constraints. Numerical case studies have been carried out to show the effectiveness of the proposed algorithm as compared to conventional droop parameter selection criteria typically adopted in the literature. 相似文献
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Mansoureh Zangiabadi Rene FeuilletHamid Lesani Nouredine Hadj-SaidJan T. Kvaløy 《Energy》2011,36(3):1703-1712
In this paper, the performance of customer-owned distributed generation (DG) units is quantified from different perspectives through an uncertainty study. A Monte Carlo-based method is applied to assess the stochastic operation of the customer-owned DG units in the power distribution system. Several cases are studied to analyze the impact on system performance of using such generators, with the emphasis on benefits. The results of the studied cases show that proper operation of customer-owned DG units placed close to significant consumption centers offers several benefits which lead to significant energy savings and improvement in the performance indices while maintaining the cost-effectiveness. Furthermore, based on the energy demand, different electricity price scenarios considering a cost sensitivity analysis are performed to indicate how the variations in electricity price influence each scenario’s feasibility. It is concluded that implementation of a proper energy purchase policy, and allocating the benefits of DG units to the owners, improves the economic performance of their investments and encourages customer DG developers to connect DG to the distribution network. 相似文献
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为实现分布式光伏系统综合发电收益最优,首先建立了光伏DG系统综合收益模型,并结合工程实践,归纳出组成光伏DG系统的四种典型拓扑结构,通过分析拓扑结构中各节点特点,提出直流系统电压等级、系统容量配比、系统集成简化、系统功率平衡四种影响分布式光伏综合发电收益的关键指标;其次分析各关键指标的经济变量,得出光伏DG系统总体优化成本变量曲线。研究结果表明,随装机容量的增加,系统总体成本相应增加,度电收益基本稳定;综合收益模型优化后成本降低,度电收益提高。研究结果为降低工程造价和单位度电成本提供借鉴。 相似文献
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规模化的分布式电源接入配电网后造成了电压高间歇性波动,影响了无功补偿设备的调节效果。提出基于相似搜索与多开端重组的多目标无功优化算法,考虑了非平滑补偿设备的日投切次数限制,加入变化的次数成本约束,调节尺度为1 h;DG和SVG的实时平滑调节设备,调节尺度为5 min,进行超短期预测反馈调节,优化目标为电压偏差、网损和调控成本综合最优。求解算法采用改进的多目标粒子群算法,运用相似搜索技术,调用适用性最高的历史无功方案作为方案粒子加快算法的初期收敛速度;引用Pareto熵协调多目标间的适应度,同时依托Pareto解集存优能力,在算法收敛后期设计了多开端重组方法,进一步提高优化效果。经实际算例验证了该方法的有效性。 相似文献
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为响应“碳达峰、碳中和”的号召,兼顾分布式能源(DG)参与下配电网运行的经济性和环保性,该文构建一种含DG的配电网双层优化模型。该模型以DG投资运行成本及环境效益为上层目标对DG进行优化配置,并以网损和电压偏移度成本为下层目标对配电网进行无功优化。针对模型特点,提出改进麻雀算法进行模型求解,增加Tent混沌映射初始化种群,引入萤火虫扰动机制改进操作算子并优化越界处理机制维持种群多样性。仿真结果表明,该模型能有效提高配电网运行的经济环保性,并验证了改进麻雀算法在求解复杂非线性非凸含离散变量的复杂组合优化问题上的优势。 相似文献
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虚拟电厂(Virtual power plant, VPP)能有效减小新能源对电网的冲击,提高供电可靠性。本文在分析了VPP各分布式电源(Distributed generator, DG)发电成本的基础上,构建了计及环境效益的含风力发电、光伏发电、小水电和微型燃气轮机发电的VPP经济性优化调度模型,设计了基于小水电季节特性的VPP运行策略。以各时段内VPP实际出力跟踪计划出力、同时VPP发电成本和环境成本最小为目标,通过粒子群算法计算得到VPP各DG的出力。讨论了丰水期、平水期和枯水期VPP完成计划出力时微型燃气轮机出力系数,比较了丰水期、平水期和枯水期VPP发电成本和环境成本,并基于火力发电的环境成本计算了丰水期、平水期和枯水期VPP环境效益。实验结果验证了所建模型和运行策略的合理性,并表明VPP能有效平抑新能源出力偏差,降低DG发电总成本。 相似文献
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Promotion strategy of clean technologies in distributed generation expansion planning 总被引:1,自引:0,他引:1
Distributed generation expansion planning (DGEP) has been frequently reported in the literature around the world. In this scope, renewable technologies which are considered as a kind of distributed generations are developing due to their environmental benefits. However, only a few renewable energies have proven to be competitive so far, while their economic viability is also limited to certain regions of the world. In this paper, an encouraging mechanism is proposed in favor of clean technologies in the planning process. This mechanism is defined based on a grant function of emission not polluted which is paid to DG owners to promote renewable and clean technologies. In the planning process, a multi-objective optimization algorithm is applied to produce a Pareto set of optimal planning schemes by taking into account different objective functions (cost and grant functions). The best planning scheme among the Pareto set is chosen based on a composite utility which are obtained through a Monte Carlo simulation of uncertain situations. Distributed generation technologies which are considered in this paper are conventional and renewable technologies, namely photovoltaic (PV), wind turbine (WT), fuel cell (FC), micro turbine (MT), gas turbine (GT), and reciprocal engine (RE). To assess the ability of the proposed method, a typical distribution system is used for expansion planning under two environmental scenarios. 相似文献
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This paper attempts to present the state of art of research work carried out on the optimal planning of distributed generation (DG) systems under different aspects. There are number of important issues to be considered while carrying out studies related to the planning and operational aspects of DG. The planning of the electric system with the presence of DG requires the definition of several factors, such as: the best technology to be used, the number and the capacity of the units, the best location, the type of network connection, etc. The impact of DG in system operating characteristics, such as electric losses, voltage profile, stability and reliability needs to be appropriately evaluated. For that reason, the use of an optimization method capable of indicating the best solution for a given distribution network can be very useful for the system planning engineer, when dealing with the increase of DG penetration that is happening nowadays. The selection of the best places for installation and the preferable size of the DG units in large distribution systems is a complex combinatorial optimization problem.This paper aims at providing a review of the relevant aspects related to DG and its impact that DG might have on the operation of distributed networks. This paper covers the review of basics of DG, DG definition, current status of DG technologies, potential advantages and disadvantages, review for optimal placement of DG systems, optimizations techniques/methodologies used in optimal planning of DG in distribution systems. An attempt has been made to judge that which methodologies/techniques are suitable for optimal placement of DG systems based on the available literature and detail comparison(s) of each one. 相似文献