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对水轮机调节系统建立数学模型,利用美国Mathworks公司的MATLAB软件,对通常的水轮机调速器水电站试验项目(空载频率波动、空载扰动、甩负荷)进行初步的仿真。 相似文献
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为编制有关技术标准和推广采用调压阀代替调压井工程措施,开展了水轮机调节系统通用仿真程序的开发:研发了描述水轮机的非线性特性的数据文件;考虑了水击模型对水轮机调节系统过渡过程的影响;计算分析时认真考虑了水轮机调速器主配压阀非线性特性的影响;特别给出了一有压隧洞向三台水轮发电机供水时的水压力数学模型。通过计算证明:水轮发电机组自动启动、空载扰动自动调节、带负荷自动调节、甩负荷自动调节工况下,只要能满足水轮机发电机组稳定运行要求,就可以采用调压阀替代调压井。 相似文献
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魏守平 《水电自动化与大坝监测》2010,34(1):5-12
介绍了水轮机调节系统机组甩100%额定负荷特性和接力器不动时间的仿真结果,给出了机组甩100%额定负荷的动态仿真曲线.仿真结果有助于加深对水轮机调节系统基本原理的理解,也有助于了解被控制系统(调节对象)参数和水轮机控制系统(调速器)参数对水轮机调节系统机组甩100%额定负荷和接力器不动时间特性的影响. 相似文献
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为了更加全面地了解和掌握水轮机调速系统的组成结构和不同工况下的特性,在大量研究理想条件下水轮机调节系统建模与仿真结果的基础上,对水轮机调节系统进行线性和非线性建模,并运用matlab/simulink对水轮机调节系统的线性和非线性动态特性进行仿真研究,从而得到了线性条件下空载频率波动和功率扰动波动响应曲线以及非线性环节的系统响应,并对这2种条件下的转速和接力器行程曲线进行了对比分析。分析结果表明,在小波动情况下适合运用线性模型,在大波动情况下适合运用非线性模型,而且这2种情况下得到的结果相差无几,均能反映同一系统的动态过程。该结论将有助于水轮机调节系统在不同工况下的控制。 相似文献
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水轮机调节系统的MATLAB仿真模型 总被引:6,自引:5,他引:1
魏守平 《水电自动化与大坝监测》2009,33(4):7-11
介绍了水轮机调节系统建模及其分析方法.仿真模型是基于MATLAB Simulink建立的,能实现水轮机调节系统空载运行、甩100%额定负荷、接力器不动时间、孤立电网运行和一次调频等动态过程的仿真.仿真结果有助于加深对水轮机调节系统基本原理的理解,也有助于了解被控制系统参数(调节对象)和水轮机控制系统(调速器)参数对水轮机调节系统动态特性的影响. 相似文献
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基于模糊神经网络的水轮发电机组甩负荷过程调速器开度模式控制方法,能够快速稳定甩负荷过程中水轮发电机组的运行频率,保障电力系统平稳运行。构建水轮发电机组调速器数学模型,以模型中3个关键调节系数为目标输出,发电机组转速的误差变化率与误差为目标输入,设计5层模糊神经网络模型与控制规则;通过该模型依据此控制规则,模糊推理与模糊化目标输入,并持续迭代学习训练后,输出3个关键调节系数,向PID控制器内输入此类系数;由PID控制器以此输入为依据,控制水轮发电机组甩负荷过程调速器的开度模式,获得稳定频率输出。结果显示,该方法可通过对实验水轮发电机组甩不同额度负荷过程中调速器开度模式的控制,有效调整并稳定不同甩负荷过程中机组的运行频率,且控制中的控制精度较高,调整用时与超调量均较低,综合控制效果理想。 相似文献
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在水电站设计中,以新型调压阀及其控制系统替代传统调压井具有显著经济效益。基于自行研制的带调压阀的水轮机调速器实时仿真系统和包含水轮机、发电机、引水系统、水轮机调速器等环节在内的水轮机调节系统过渡过程计算软件,采用水轮机流量、力矩特性矩阵法表征水轮机动态特性,建立了刚性水击条件下一洞多机输水系统的数学模型;对带有主配压阀非线性特性的PID调速器,建立了带调压阀的转桨式水轮机调节系统数学模型。研究表明:通过计算只要保证水轮发电机组启动、空载扰动、带负荷、甩负荷自动调节工况下,水轮机调节系统过渡过程满足稳定运行要求,水电站就可以采用调压阀而不设调压井。最后,计算了某具有长引水系统的转浆式水轮机过渡过程,该电站水流惯性时间常数高达27 s,装有2台转桨水轮机、1台定桨式水轮机。计算结果表明,以调压阀代替调压井后,该水轮机调节系统稳定,满足调节保证要求。 相似文献
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根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。 相似文献
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The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects. 相似文献
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In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment. 相似文献
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V. K. Konovalov O. V. Yashkin V. V. Ermakov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(2):105-109
A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed
in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash
and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers
of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional
components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect
dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system,
configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants
of dry ash utilization and the advantages of producing of size-separated particles are considered.
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Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008). 相似文献
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Peter B. Bayley 《河流研究与利用》1991,6(2):75-86
The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed. 相似文献
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简述天湖水电站投运以来各种故障的表现形式,分析其原因,提出了相应的处理方法及措施,并对合理利用国内外设备提出建议。 相似文献