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101.
简介了全分布式控制网络构成的水电厂微机监测系统的结构、功能和故障诊断系统。它不仅能实时监测机组运行参数,且可对事故做出快速反应,大大提高了水电厂安全运行水平。由于网络采用总线拓扑结构和真正的全分布方式,因而在老电厂的技术改造中,不仅运行可靠、抗干扰能力强,且布置安装简便,投资省。 相似文献
102.
优化运行理论在泵站综合自动化系统中的应用 总被引:5,自引:1,他引:5
利用改进的神经元网络构建了泵站流量以及效率预测模型,并利用改进的遗传算法构建了泵站优化模型。将这两个模型应用到泵站综合自动化系统中,可以完成对泵站流量及效率的准确预测,并在此基础上实现泵站的优化运行。讨论了泵站优化运行理论在泵站综合自动化系统中应用的步骤和方法。 相似文献
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因现有润滑方程中的流量因子系数值有限,不能满足摩擦学研究的需要。本文利用BP神经网络,使用L—M规则,对润滑方程中流量因子系数进行了预测。训练时,以微凸体的纵横比v为输入样本,输出样本为压力流量因子的两个系数。结果表明:训练良好的BP网络输出数据与实测数据吻合较好,并具有收敛速度快等特点。 相似文献
106.
为了有效提高配电网络的收敛速度,避免不成熟收敛,在传统遗传算法的基础上,提出了一种快速环路分解遗传算法。提出用支路的开关状态(0或1)作为控制参数,避免繁琐的编码方法,缩短了染色体的长度,同时对交叉位置的选取和变异提出了独特的方案,并用于网络重构中,极大地提高了计算效率。 相似文献
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A model for optimal operation of water supply/irrigation systems of various water quality sources, with treatment plants, multiple water quality conservative factors, and dilution junctions is presented. The objective function includes water cost at the sources, water conveyance costs which account for the hydraulics of the network indirectly, water treatment cost, and yield reduction costs of irrigated crops due to irrigation with poor quality water. The model can be used for systems with supply by canals as well as pipes, which serve both drinking water demands of urban/rural consumers and field irrigation requirements. The general nonlinear optimization problem has been simplified by decomposing it to a problem with linear constraints and nonlinear objective function. This problem is solved using the projected gradient method. The method is demonstrated for a regional water supply system in southern Israel that contains 39 pipes, 37 nodes, 11 sources, 10 agricultural consumers, and 4 domestic consumers. The optimal operation solution is described by discharge and salinity values for all pipes of the network. Sensitivity of the optimal solution to changes in the parameters is examined. The solution was found to be sensitive to the upper limit on drinking water quality, with total cost being reduced by 5% as the upper limit increases from 260 to 600 mg Cl l–1. The effect of income from unit crop yield is more pronounced. An increase of income by a factor of 20 results in an increase of the total cost by a factor of 3, thus encouraging more use of fresh water as long as the marginal cost of water supply is smaller than the marginal decrease in yield loss. The effect of conveyance cost becomes more pronounced as its cost increases. An increase by a factor of 100 results in an increase of the total cost by about 14%. The network studied has a long pipe that connects two distinct parts of the network and permits the supply of fresh water from one part to the other. Increasing the maximum permitted discharge in this pipe from 0 to 200 m3 h–1 reduces the total cost by 11%. Increasing the maximum discharge at one of the sources from 90 to 300 m3 h–1 reduces the total cost by about 8%. 相似文献
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N. Zapata E. Playán A. Martínez-Cob I. Sánchez J.M. Faci S. Lecina 《Agricultural Water Management》2007
In this paper, a contribution to the design of collective pressurised irrigation networks in solid-set sprinkler-irrigated windy areas is presented. The methodology is based on guaranteeing minimum on-farm performance, using a historical hourly wind speed database and a ballistic solid-set irrigation simulation model. The proposed method was applied to the Montesnegros Irrigation District (central Ebro basin, Spain). The district irrigates an area of 3493 ha using an on-demand schedule. The average wind speed in the area is 2.8 m s−1. An analysis of district water records showed that farmers often reduce water demand when the wind speed is high, but their irrigation decision making is limited by the capacity of the irrigation network and by the unpredictable character of local winds. Simulations were performed for 11 irrigation seasons, 2 triangular sprinkler spacings (18 m × 18 m and 18 m × 15 m), and 2 sprinkler models. The percentage of monthly suitable time for irrigation was determined for four management strategies. The first one was based on a wind speed threshold (3 m s−1), while the other three were based on three levels (standard, relaxed and restrictive) of two irrigation performance parameters: the Christiansen Uniformity Coefficient (CU) and the Wind Drift and Evaporation Losses (WDEL). The standard strategy classified the time as suitable for irrigation when CU ≥ 84% and WDEL ≤ 20%. The thresholds limits of the irrigation parameters for the relaxed strategy were CU ≥ 80% and WDEL ≤ 25%. Finally, the restrictive strategy used thresholds of CU ≥ 90% and WDEL ≤ 15%. The suitable time for the first strategy (56%) was always lower than for the standard and the relaxed strategies (with respective average values of 75 and 86%), and higher than for the restrictive strategy (30%). In order to design the collective network, the hydrant operating time was equalled to the suitable time for irrigation. The differences in the cost of the collective network plus the on-farm equipment were particularly relevant between the restrictive strategy and the other three. Differences in suitable operating time were clear between sprinkler spacings, and less evident between sprinkler models. The application of the proposed methodology may be limited by the availability of historical wind speed records and CU estimates for different combinations of sprinkler models, sprinkler spacings and wind speed. 相似文献