共查询到20条相似文献,搜索用时 11 毫秒
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In this paper, a three phase probabilistic load flow for transmission system based on point estimation method along with three phase unbalanced induction generator model for the wind farm has been proposed. The proposed method is tested on a IEEE-118 bus three phase system and accuracy of the results have been validated by comparing the results with those obtained by Monte Carlo simulation studies. The effect of variation of standard deviation of the connected loads on the system and effect on the voltage profile has also been studied. 相似文献
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无功优化是一个多变量、多约束、高维数的非线性规划问题,其离散变量与连续变量并存的特性使得传统优化算法难以对其进行求解。根据无功优化问题的特性,提出了一种适用于无功优化问题求解的引力搜索算法,该算法是受牛顿引力定律和粒子间相互作用的启发而提出来的一种新的优化算法,其理论基础深厚,物理意义明确,便于理解,简单易行。算例结果表明,引力搜索算法可以有效求解电力系统无功优化问题,且收敛速度快,数值稳定性好。 相似文献
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Wind speed as well as the power output of wind turbine generators (WTGs) have high correlations and may not be normally distributed. In this paper, the method of Zhao’s point estimate method (PEM) combined with Nataf transformation was applied into correlated probabilistic load flow (PLF) calculation. This method can deal with correlated input random variables (RVs) with normal or non-normal probability distributions. Instead of joint probability density functions (PDFs) of multivariate RVs, this method only requires data of the marginal distribution function of each input RV and their correlation coefficients. The effectiveness of the proposed method is demonstrated by the numerical tests on IEEE 14-bus and the IEEE 118-bus systems. Besides, relative average errors compared with correlated Monte Carlo Simulation (CMCS) are analyzed. 相似文献
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Abstract—This article presents a hybrid algorithm based on the particle swarm optimization and gravitational search algorithms for solving optimal power flow in power systems. The proposed optimization technique takes advantages of both particle swarm optimization and gravitational search algorithms by combining the ability for social thinking in particle swarm optimization with the local search capability of the gravitational search algorithm. Performance of this approach for the optimal power flow problem is studied and evaluated on standard IEEE 30-bus and IEEE 118-bus test systems with different objectives that reflect fuel cost minimization, voltage profile improvement, voltage stability enhancement, power loss reduction, and fuel cost minimization with consideration of the valve point effect of generation units. Simulation results show that the hybrid particle swarm optimization–gravitational search algorithm provides an effective and robust high-quality solution of the optimal power flow problem. 相似文献
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Wind power is a promising source of electric power generation since it has tremendous environmental and social benefits. The generation scheduling (GS) problem encounters several uncertainties in terms of the system's parameters such as load, reserve and available wind power generation. The modeling of those uncertainties is an important issue in power system scheduling. A fuzzy based modeling approach can be used to develop the generation schedule under an uncertain environment.In this paper, the type-2 fuzzy membership function (MF) is implemented to model the linguistic uncertainty of type-1 MF of available wind power generation which stems from opinions of different experts. The proposed approach is applied to two test systems (six and twenty-six conventional generating units both with two wind farms) and the results of generation scheduling using both fuzzy modeling type-1, and type-2 are presented. These results demonstrate that the advantage of using the type-2 fuzzy to model the linguistic uncertainty of the type-1 MF. This paper demonstrates how unit scheduling in an uncertain environment of type-1 fuzzy MF modeling can be performed just by using a single type-2 fuzzy MF when all type-1 MF were in the footprint of uncertainty (FOU) of type-2 MF. 相似文献
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Portfolio theory has found its model in numerous engineering applications for optimizing the electrical generation mix of an electricity area. However, to have better performance of this theory, this paper presents a new heuristic method as known modified artificial bee colony (MABC) to portfolio optimization problem. Moreover, we consider both dis-patchable and non-dis-patchable constrains variables and energy sources. Note that the proposed MABC method uses a Chaotic Local Search (CLS) to enhance the self searching ability of the original ABC algorithm. Resulting, in this paper a portfolio theory-based MABC model that explicitly distinguishes between electricity generation (energy), installed capacity (power) and actual instantaneous power delivery is proposed. Therefore, in this model, the uncertainties of wind power and ramp-up/down constrains of traditional power plants are correctly considered in the investment cost. The numerical results show the great potential of proposed model with lowest risk on generation cost. Also, they are show that MABC approach is successful in portfolio optimization. 相似文献
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首先建立采用迭代费用惩罚系数的单目标水火电系统环境经济优化调度模型;其次为解决梯级水电站由于时间耦合性和空间相关性而带来的同时处理发电流量约束、库容约束和动态水量平衡约束的难题,给出约束条件的启发式处理方法,使得在满足上述复杂约束的同时,更利于最优解的搜寻。对总装机容量为2 975 MW的水火电系统(包含一个含4水电机组的梯级水电站和3个火电机组)进行仿真计算,结果不仅表明了该启发式约束条件处理方法的可行性和有效性,而且对比进化算法和差分进化算法所得结果,每天的燃料费用分别降低了4 303.96$和1 311.96$,污染气体排放量分别减少8 231.37 lb和1 522.37 lb。 相似文献
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基于配电网的特点,建立了以网损最小为目标的配电网无功优化模型。通过万有引力搜索算法,给出配电网无功优化的步骤,确定并联电容器的无功补偿容量。算例分析表明该无功优化模型可靠有效,可以有效减少系统网损,提高节点电压水平。 相似文献
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风电场风速和发电功率预测研究 总被引:140,自引:11,他引:129
风速预测对风电场和电力系统的运行都具有重要意义。对风速进行比较准确的预测,可以有效地减轻或避免风电场对电力系统的不利影响,同时提高风电场在电力市场中的竞争能力。基于时间序列法和神经网络法,该文对风速预测进行了研究,提出了预测风速的时序神经网络法。该方法用时间序列法建模,得到风速特性的基本参数,并用这些参数选择神经网络的输入变量;为了提高预测精度,提出了滚动式权值调整手段。该方法有效地提高了风速预测的精度。 相似文献
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本将GSA应用于求解电力系统的无功优化问题,发现其寻优速度快,数值稳定性好,可以灵活处理离散变量和连续变量算例仿真结果表明,GSA在求解RPO问题时寻优速度和数值稳定性均优于PSO。 相似文献
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A. ?ima Uyar Belgin Türkay 《International Journal of Electrical Power & Energy Systems》2011,33(6):1236-1242
This paper proposes a new way of applying a differential evolution algorithm to short-term electrical power generation scheduling. Traditionally, the problem is divided into two subproblems. An evolutionary algorithm, which works with binary decision variables, is applied to the first subproblem to find a low cost scheduling of power generators, satisfying some operational constraints. Then, the lambda-iteration method, is used to calculate the power generated by the online generators. In this study, the problem is treated as a whole for the first time in literature and an application of a real-valued differential evolution algorithm is proposed. This approach eliminates the use of an iterative local search technique such as lambda-iteration in all solution evaluations. Through comparisons with results from literature, it is shown that the proposed method achieves a similar solution quality to existing methods, without needing the time consuming lambda-iteration step. Finally, the new approach is applied to real-world data from the Turkish interconnected power network. 相似文献
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超短期发电计划优化在电力系统调度运行中发挥着越来越重要的作用,但由于其是一个非线性整数约束优化问题,数学模型复杂,很难从理论上找到全局最优解。针对电力系统发电计划优化问题,引入免疫遗传算法,很好地解决了遗传算法局部收敛的问题,实现了群体收敛性和个体多样性间的动态平衡调整,能快速准确求解,及时调整超短期发电计划方案,从而达到安全经济环保调度,优化资源配置的效果。 相似文献
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火电一抽水蓄能联合运营能够显著改善系统经济性和环保性。根据实际应用中系统对于调度方案经济性和环保性的需求差异,构建了基于权重系数的火电一抽水蓄能运营系统组合模型,分析引入抽水蓄能机组对系统发电成本和排放量的影响。模型以包括燃料成本、启动成本和排放成本在内的总成本最小为目标函数,并在目标函数中设定了可调的成本权重系数。其次,提出了一种混沌算法改进的引力搜索算法,利用混沌算法进行局部搜索优化,求解火电一抽水蓄能联合运营模型。算例分析验证了模型的合理性和算法的有效性,研究结果表明,抽水蓄能机组的引入能够有效改善电能生产的经济效益和环保效益。 相似文献
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分布式电源接入配电网将直接改变潮流分布,而网络重构通过改变开关的开合状态以提高供电的可靠性和经济性。以降低网损和缺供电量为目标,以可调度DG的有功输出和开关状态为优化变量,建立多目标协调优化的配电网络重构的数学模型。将引力搜索算法、Pareto最优解理论和模糊决策理论相结合,提出了求解上述模型的多目标混合优化方法,以实现配电网结构和DG出力的协同优化。通过对IEEE33节点测试系统的仿真结果,表明所提出方法能够实现DG出力和网络重构的综合优化和多目标优化,并且在全局寻优能力和收敛速度上表现出色。 相似文献
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采用多局部搜索策略的无功优化多模因算法 总被引:1,自引:1,他引:1
引入局部搜索策略可提高无功优化进化算法的收敛性能,但目前引入的局部搜索策略都比较单一,不能取得很好的收敛效果。因此该文提出一种基于多局部搜索策略的无功优化多模因算法。该算法根据现有的多种局部搜索策略,提出包含修正型、定向型和随机型3类模因的无功优化模因池。在IEEE 30节点标准系统上的仿真表明,新算法可发挥各类局部搜索策略的特点,具有良好的收敛特性。此外,该文还比较不同作用比例的多模因算法,分析作用比例与算法效率的关系,为局部搜索策略在无功优化中的进一步应用提供参考。 相似文献
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Cascaded H-bridge multilevel inverter (CHB-MLI)-based shunt active power filter (SAPF) is one of the finest solutions for power quality improvement in case of medium-voltage distribution sector. Performance of SAPF degrades due to the presence of DC offset and harmonics in the grid voltage since this will result phase angle and frequency error. Therefore, modified single-phase synchronous reference frame theory comprising of advanced PLL is presented in this article. The advanced PLL can track frequency and phase angle accurately even though source voltage is having DCor harmonic content. A detailed mathematical modeling and stability analysis of this PLL is presented using Routh-Hurwitz criteria. A novel systematic design procedure using gravitational search algorithm (GSA) and an Eigen value analysis is proposed for calculating optimal PLL parameters. Closed-loop SAPF control stability is tested using root-locus analysis. An extensive experimental analysis of the proposed control applied to CHB-MLI-based SAPF has been performed under distorted source voltage and non-linear loading conditions to show the effectiveness of the proposed control over recently published work. Source current maintains its sinusoidal shape, properly synchronized with grid voltage and having distortion limit in compliance with IEEE-519 standard irrespective of source voltage conditions during the operation of SAPF. 相似文献
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