共查询到20条相似文献,搜索用时 93 毫秒
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将基于矢量距理论的免疫算法应用于最优潮流计算,并在计算中引进自适应交叉和变异算子,根据抗体个体的适应度大小来动态调整交叉率和变异率,很大程度上保护了每代中的较优个体。根据最优潮流中控制变量的特点,运用浮点数编码方法,无需解码,计算简单;通过用IEEE 30节点标准测试系统计算多次,燃料耗费显著改善,表明了所用方法的可行性和有效性。 相似文献
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遗传算法是近年来被广泛应用于无功优化的一种新型的优化算法。结合配电网的特征,对遗传算法的选择操作、交叉和变异算子、终止判据等核心操作进行改进,提出一种适合于配电网无功优化的改进遗传算法。计算实例表明,其优化效果优于传统遗传算法。 相似文献
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水文变异综合诊断方法及其应用研究 总被引:22,自引:2,他引:22
提出了一种水文时间变异综合诊断方法。首先采用Hurst系数等方法对序列进行初步检验,判断序列是否存在变异;然后用多种检验方法对序列进行详细诊断,得到多种检验结果;最后对检验结果评分,计算综合权重,找出权重最大的点,并结合实际水文调查分析对该点进行确认,从而得到最可能变异点。该方法已应用于潮白河45a径流量变异分析中,解决了单一检验方法检验结果不合理、多种检验方法检验结果不一致的问题。 相似文献
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在建立无功,电压实时优化控制模型的基础上。提出了一种基于改进粒子群算法的地区电网无功,电压实时优化控制实现方法。该方法采用增量启动策略决定控制设备参与优化的程度;通过综合考虑负荷大小、限振系数与动作比例等因素模糊推理出表征动作代价的模糊控制成本。更加合理地限制和分配控制设备的动作次数:将粒子群算法与无功,电压控制特点相结合以改善初始粒子质量、缩小寻优空间并引入交叉算子提高算法的计算速度和效率。以某一实际地区电网为例进行无功,电压实时优化仿真计算,结果表明,所提算法和控制策略是可行和有效的。 相似文献
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本文提出一种快速确定气体横掠换热管束质量流速的计算方法,该质量流速将热交换器传热和阻力限制“耦合”在一起加以考虑,具有接近真值,迭代次数少,收敛快等优点,是该类热交换器设计气体流速的一种较佳确定方法。 相似文献
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摘要:电能质量综合评估是电能质量定价的主要依据之一。本文采用理想区间模型对电能质量进行综合评估。首先,分别采用线性目标规划模型和变异系数法确定主观与客观权重,根据博弈论集化的思想求取各指标的综合权重;其次,基于理想区间模型计算样本指标值与理想区间的贴近度,从而对电能质量进行综合评估;最后,运用算例验证该方法的可行性和合理性。该方法不仅能整体评估电能质量,且可细化同一等级内质量差异。 相似文献
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水体环境质量评价的物元识别模型 总被引:2,自引:0,他引:2
将物元分析理论与优化技术结合起来,提出了一种水体环境质量评价的物元识别模型.实例计算表明,该模型用于水体环境质量评价具有计算简便等优点,且计算结果与其它评价方法基本一致,为水体环境质量评价提供了一个新途径 相似文献
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强制进化随机游走算法优化换热网络时具有程序简单、全局搜索能力强等特点,但在优化过程中不同的进化阶段对进化概率需求不同,算法中设置单一的进化概率难以满足实际进化需求。因此,提出一种进化概率差异化策略,该策略的核心思想是智能识别流股的换热程度,动态调整进化概率,对存在公用工程的流股强制参与进化,使算法在前期具有较强的结构搜索能力;完全换热的流股通过降低进化概率,提升算法全局的精细搜索能力。采用15SP和39SP算例进行验证,所获年综合费用分别为1 494 690和1 894 477$/a,验证了该策略能够提升算法的优化效率与质量。 相似文献
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Wireless monitoring algorithm for wind turbine blades using Piezo‐electric energy harvesters 下载免费PDF全文
Wind turbine blade failure can be catastrophic and lead to unexpected power interruptions. In this paper, a Structural Health Monitoring (SHM) algorithm is presented for wireless monitoring of wind turbine blades. The SHM algorithm utilizes accumulated strain energy data, such as would be acquired by piezoelectric materials. The SHM algorithm compares the accumulated strain energy at the same position on the three blades. This exploits the inherent triple redundancy of the blades and avoids the need for a structural model of the blade. The performance of the algorithm is evaluated using probabilistic metrics such as detection probability (True Positive) and false alarm rate (False Positive). The decision time is chosen to be sufficiently long that a particular damage level can be detected even in the presence of system sensor noise and wind variations. Finally, the proposed algorithm is evaluated with a case study of a utility‐scale turbine. The noise level is based on measurements acquired from strain sensors mounted on the blades of a Clipper Liberty C96 turbine. Strain energy changes associated with damage from matrix cracking and delamination are simulated with a finite element model. The case study demonstrates that the proposed algorithm can detect damage with a high probability based on a decision time period of approximately 50–200 days. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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CHEN Wei-qiang 《电网与水力发电进展》2007,(7)
针对配电网系统的单相高阻接地故障,提出了一种基于概率分析的故障检测与定位方法。该方法适用于零序不接地或经消弧线圈接地系统,利用数据采集系统采集到的零序电压和各线路零序电流的变化,进行各线路故障概率计算,在最大故障概率条件下进行故障定位。算法简洁有效,现场实测数据证明了该算法的正确性和实用性。 相似文献
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《Energy》2005,30(5):693-708
Hourly wind speed time series data of two meteorological stations in Malaysia have been used for stochastic generation of wind speed data using the transition matrix approach of the Markov chain process. The transition probability matrices have been formed using two different approaches: the first approach involves the use of the first order transition probability matrix of a Markov chain, and the second involves the use of a second order transition probability matrix that uses the current and preceding values to describe the next wind speed value. The algorithm to generate the wind speed time series from the transition probability matrices is described. Uniform random number generators have been used for transition between successive time states and within state wind speed values. The ability of each approach to retain the statistical properties of the generated speed is compared with the observed ones. The main statistical properties used for this purpose are mean, standard deviation, median, percentiles, Weibull distribution parameters, autocorrelations and spectral density of wind speed values. The comparison of the observed wind speed and the synthetically generated ones shows that the statistical characteristics are satisfactorily preserved. 相似文献
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Tian W.D. Sutanto D. Lee Y.B. Outhred H.R. 《Energy Conversion, IEEE Transaction on》1989,4(4):567-574
The authors describe a novel cumulant method of probabilistic power system simulation using the Laguerre polynomial expansion. In this method, Laguerre polynomials are used for obtaining the equivalent load duration probability density function from cumulants representing the load and generator outage probability density functions. A recursive algorithm is used for calculating moments and cumulants which enables practically any number of cumulants to be used in the simulation. The results of testing the method on the IEEE Reliability Test System are presented. The accuracy and computational efficiency of the method are compared with those of the conventional cumulant method based on the Hermite polynomial expansion 相似文献
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针对传统小波神经网络在电力系统短期负荷预测中存在预测结果的精确度依赖初始网络参数的问题,提出了一种基于改进遗传算法优化的小波神经网络短期负荷预测模型。为了保证神经网络在训练过程中,各个层的权值和阈值按最优方向变化,将遗传算法引入小波神经网络,利用遗传算法寻优能力指导权值和阈值进行优化。将概率分布策略用于遗传算法的种群交叉和变异过程,解决遗传算法在中后期搜索精度差,收敛速度慢等问题。应用结果表明,与基本的小波神经网络的预测模型相比,在只考虑短期负荷历史数据的情况下,通过均方根误差计算比较,基于改进遗传算法优化的小波神经网络短期负荷预测模型具有更高的预测精度。 相似文献
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《International Journal of Thermal Sciences》2007,46(7):649-661
A stochastic particle swarm optimizer (SPSO) algorithm, which can guarantee the convergence of the global optimization solution with probability one, is adopted to estimate the parameters of radiation system. To illustrate the performance of this algorithm, three cases are investigated, in which the source term, the extinction coefficient, the scattering coefficient, and the non-uniform absorption coefficients in a one-dimensional slab are retrieved. The directional radiative intensity, reflectance and transmittance, radiative flux simulated by discrete ordinate method (DOM) are served as input for the inverse analysis, respectively. By SPSO algorithm presented, all these radiative parameters could be estimated accurately, even with noisy data. In conclusion, the SPSO algorithm is proved to be fast and robust, which has the potential to be implemented in various fields of inverse radiation problem. 相似文献
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