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In this paper, an H(∞) robust controller has been designed for an identified model of MONTAZER GHAEM power plant gas turbine (GE9001E). In design phase, a linear model (ARX model) which is obtained using real data has been applied. Since the turbine has been used in a combined cycle power plant, its speed and also the exhaust gas temperature should be adjusted simultaneously by controlling fuel signals and compressor inlet guide vane (IGV) position. Considering the limitations on the system inputs, the aim of the control is to maintain the turbine speed and the exhaust gas temperature within desired interval under uncertainties and load demand disturbances. Simulation results of applying the proposed robust controller on the nonlinear model of the system (NARX model), fairly fulfilled the predefined aims. Simulations also show the improvement in the performance compared to MPC and PID controllers for the same conditions. 相似文献
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以液压型风力发电机组为研究对象,针对其液压调速系统恒转速输出问题,建立了定量泵-变量马达液压调速系统数学模型,得到了系统泄漏、系统压力瞬态调整和模型参数误差对机组恒转速输出的补偿控制数学模型。以数学模型为基础,给出了液压型风力发电机组恒转速输出补偿控制方法。以30kV·A液压型风力发电机组实验台为仿真和实验基础,对提出的控制方法展开研究。仿真和实验结果表明,液压型风力发电机组恒转速输出补偿控制方法具有较好的控制效果,可实现机组的恒转速输出的高精度控制。 相似文献
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在无载液压缸动态特性良好的基础上,将其与伺服电机控制的计量泵并联连接,设计一种复合型动态流量计,可实现对连续偏置的动态流量精确测量。计量泵调节无载液压缸的活塞位置的同时测量偏置稳态流量,无载液压缸测量高频的动态流量,解决了无载液压缸的行程受限问题。结合复合型动态流量计的结构特性,提出了一种新的泵控缸动平衡控制方案来调节液压缸的活塞位置,提高了活塞的控制和响应速度;同时针对流量测量中的流体泄漏建立流量泄漏补偿模型,使动态流量的测量更精确。搭建实验系统,利用LabVIEW编写实验程序,结合涡轮流量计进行稳态流量测量校准。实验结果表明:复合型流量计方案可行,在稳态流量的测量中可以实现高精度的测量,在动态流量测量中,动态性能良好。 相似文献
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《Measurement》2014
The leakage is a common fault in the hydraulic system of the large forging hydraulic press. The large forging hydraulic press is usually used in the high temperature situations. Hence once leakage happens, the fire hazard can be caused and the huge economic losses can be taken place. Therefore, detecting and positioning leakage is also of great importance for the fault diagnosis of hydraulic system. A new method of fault diagnosis is proposed based on extracting leakage information in this paper. Firstly, the double inverse limit space is established. Secondly, the leakage information will be mapped into the double inverse limit space via the homeomorphism mapping. The leakage is detected with equicontinuity. The leakage positioning can be realized according to the topological transitivity in the double inverse limit space. Finally, the method of fault diagnosis is feasible according to the simulation results. Hence the fault diagnosis of hydraulic system in large forging hydraulic press is realized by adopting the method proposed in this paper. The leakage can be forecasted in real-time. 相似文献
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以液压型风力发电机组为研究对象,输出高质量电能为研究目标,针对机组存在的转速和转矩解耦问题展开研究。建立定量泵-变量马达液压传动系统数学模型。从液压传动系统出发,探究影响机组电能输出质量的关键因素,分析该多输入-多输出系统存在的耦合问题,并采用前馈解耦补偿控制方法解耦。分析变量马达和比例节流阀对液压系统输出转速与转矩的控制规律,得到基于高电能质量控制的转速和转矩解耦控制器。以30kVA液压型风力发电机组半物理仿真实验台为基础,针对提出的控制方法展开研究。仿真和实验结果表明:液压型风力发电机组输出的转速和转矩实现了解耦控制,有效地实现了液压传动系统的稳速控制和传输功率波动的平滑控制。研究结果为液压型风力发电机组高质量电能输出控制和电网友好性能提高奠定了基础。 相似文献
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Liu Jiazeng Gao Jianmin Gao Tieyu 《Journal of Mechanical Science and Technology》2012,26(4):1291-1298
An experimental study of heat transfer characteristics of steam in a square channel (simulating a gas turbine blade cooling
passage) with two opposite surfaces roughened by 60 deg parallel ribs was performed. The ranges of key governing parameters
were: Reynolds numbers (Re) based on the channel hydraulic diameter (30000–140000), entry gauge pressure (0.2Mpa–0.5Mpa),
heat flux of heat transfer surface area (5kWm−2–20kWm−2), and steam superheat (13°C–51°C). The test channel length was 1000mm, while the rib spacing (p/e) was 10, and the ratio
of rib height (e) to hydraulic diameter (D) was 0.048. The test channel was heated by passing current through stainless steel
walls instrumented with thermocouples. The local heat transfer coefficients on the ribbed wall from the channel entrance to
the fully developed regions were measured. The semi-empirical correlation was fitted out by using the average Nusselt numbers
in the fully developed region to cover the range of Reynolds number. The correlation can be used in the design of new generation
of gas turbine blade cooled by steam. 相似文献
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为满足对大口径管道破损泄漏事故进行快速安全维抢修作业的需要,研制开发了大口径油气管道快速夹紧装置。该装置采用液压系统作动力,能够将大口径油气管道维抢修卡具快速的安装到油气管道泄漏位置,达到快速封堵,隔离危险源的目的,并减少经济损失及环境污染。 相似文献
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以液压型风力发电机组为研究对象,分析机组在低电压工况下的运行特性。结合低电压穿越要求,完善并分析液压型风力发电机组工作原理。建立电压跌落时风力机、定量泵-变量马达液压调速系统以及发电机的暂态数学模型。以数学模型为基础搭建MATLAB/Simulink仿真平台,并在不同跌落深度下分别对三相电压等幅跌落、两相对地短路故障和单相对地短路故障进行低电压运行特性仿真分析。研究结果揭示了不同故障下机组低电压运行的特性规律,其中电流过载与电磁转矩产生脉振是机组低电压运行的重要表征现象。研究工作将为该机型低电压穿越控制提供一定的理论基础和技术手段。 相似文献
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该文在前期液压变桨执行机构系统设计的研究基础上,利用Matlab/Simulink中SimHydraulics建立了完整的风力机液压变桨执行机构物理仿真模型,同时给出了传递函数数学建模结果,并对两种建模方法得到的液压变桨执行机构模型的稳定性作了比较分析,最后通过SimHydraulics所建液压变桨执行机构模型与风力机整机模型联合仿真,完成了风力机的变桨功率控制仿真实验.仿真结果表明,相比传递函数、状态方程、功率键合图等数学建模方法,SimHydraulics物理建模方法所建模型精确性更高,基于该模型的风力机功率控制、稳定性、可靠性等相关分析研究的准确性和可靠性也较高. 相似文献
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为提高液压型风力发电机组的电网适应性和低电压穿越能力,针对机组低电压穿越过程中的能量调控问题,提出一种基于分层控制思想的低电压穿越控制方法,即设计出基于风力机调桨控制的顶层控制、基于变量马达摆角控制的中层控制和基于节流阀开度控制的底层控制。为实现机组在控制过程中多变量的协调控制,以风力机弃风最小、惯性储能最大和节流阀能耗最小为优化目标,采用二次规划算法对多目标控制律进行规划,得到了最优控制律。通过AMESim和MATLAB/Simulink软件对多目标控制策略进行仿真分析,利用液压型风力发电机组半物理试验平台对控制律进行了验证。结果表明,所提出的控制方法可以有效降低机组在低电压穿越过程中的剩余能量,降低对发电机的冲击,提高机组的适应性。 相似文献
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Junsik Lee Jin Sub Kim Hyungsoo Lim Je Sung Bang JeongMin Seo Jeong Lak Sohn Jungho Lee 《Journal of Mechanical Science and Technology》2017,31(11):5113-5121
Effusion cooling can be one of the attractive methods of cooling in a current high-efficiency gas turbine which has a very hot gas temperature above 1600 °C. For higher effectiveness of the air cooling for a gas turbine vane and blade, the air-cooled flow through effusionholes should not overshoot into the mainstream flow but still remain within the mainstream boundary layer. The present study is intended to examine flow structure of a microscale effusion cooling for gas turbine applications through flow visualization which is highly effective to obtain better understanding of the flow physics. The air flow through effusion-holes can be visualized with an oil atomized droplets, a laser-sheet and a high-speed CCD imaging system. The qualitatively visualized results show their flow patterns and characteristics with different effusion hole size and blowing ratio for effusion cooling. A series of vortical structure can be observed within the boundary layer along the microscale effusion flat plate which provided that the effusion cooling can be a plausible candidate up to the effusion-hole size of 0.7 mm. 相似文献