非线性解析模糊控制及在水电机组控制中的应用

在解析模糊控制器的基础上,引入非线性函数建立了一种新的模糊控制器,讨论了所论模糊控制器的规则和参数在线调整方法.建立了所论模糊控制器的控制参数与常规PID控制器参数间的关系.最后给出了其在水电机组控制系统中的应用.仿真研究表明:所论模糊控制器可以显著提高水轮机调速系统的动态性能.     

Synthesis and Surface Activities of Novel Monofluoroalkyl Phosphate Surfactants

Two novel environmentally friendly fluorinated surfactants, disodium monofluoroalkyl phosphates were synthesized using phosphorus pentoxide, i.e. H(CF₂)₆CH₂OPO(ONa)₂ and H(CF₂)₆CH₂OCH₂CH₂OPO(ONa)₂. The novel synthesized fluorinated surfactants have a high thermal stability on the basis of Thermogravimetric Analysis. Their surface properties were also examined with the aim to have similar surface tensions of dilute aqueous solutions when compared with the conventional fluorocarbon surfactants, ammonium perfluorooctanoate. The two synthesized monofluoroalkyl phosphates can respectively reduce the surface tension of water to 23.73 mN/m at 78.3 mmol/L and 21.38 mN/m at 20.93 mmol/L. In addition, the Krafft points are both below 0 °C.     

三氟氯乙烯-醋酸乙烯酯-叔碳酸乙烯酯含氟乳液的合成

以三氟氯乙烯、醋酸乙烯酯、叔碳酸乙烯酯为主要原料,制备固相质量分数约为33%,乳胶粒子粒径为151～205 nm的一系列稳定的三元含氟共聚物乳液,并对聚合物结构进行红外光谱表征,通过透射电镜观察乳胶粒子的形态,讨论乳化剂全氟辛酸铵用量、引发剂过硫酸钾用量及反应温度对共聚胶乳粒径的影响和单体配比对乳液最低成膜温度和聚合物玻璃化温度的影响。结果表明,随着全氟辛酸铵用量和过硫酸钾用量增大和反应温度升高,乳液中乳胶粒子的粒径变小;随着过硫酸钾、全氟辛酸铵用量增加,乳胶粒子数量逐渐增加;随着叔碳酸乙烯酯用量的增加,乳液最低成膜温度和聚合物玻璃化温度都变小。     

高强度织构对2524铝合金疲劳性能的影响

对分别含有高强度高斯织构和高强度立方织构状态的2种2524-T4铝合金板材的疲劳裂纹扩展速率和短裂纹扩展行为进行研究,用扫描电镜(SEM)观察疲劳试样断口形貌和疲劳短裂纹的扩展路径,研究织构类型对合金疲劳性能的影响。结果表明:高斯取向晶粒能够提高材料疲劳裂纹扩展的门槛值及增强疲劳裂纹的扩展抗力,使材料在更高的应力强度因子下发生失稳扩展;而高强度立方织构对疲劳性能的影响相对较小。在近门槛区,高斯晶粒通过裂纹偏转的形式有效阻碍短裂纹扩展,在稳态扩展区,高斯晶粒能明显降低疲劳裂纹的扩展速率,高斯织构还能延长合金疲劳裂纹稳态的扩展区,提高合金的疲劳损伤容限。因此,高强度高斯织构的2524-T4铝合金板材比立方织构的合金具有更好的疲劳性能。     

An intelligent discontinuous control strategy for hydroelectricgenerating unit

An intelligent discontinuous control strategy for water turbine regulation is presented in this paper. Taking reliability and the static and dynamic performance of the system as the ultimate goal, it combines the classical fuzzy control theory and tri-state valve technology to form a discontinuous controller. This results in a simplified water turbine governor, both in software and hardware. The proposed control strategy greatly improves system performance and reduces the cost by totally eliminating the electro-hydraulic transducer. Simulation results show it has a satisfactory performance     

沙坪水电站正常高水位的确定

沙坪水电站正常高水位的确定主要考虑天然落差的利用、库区淹没、综合利用等因素，并按全面的经济评价判据来确定。表2个。     

Control/maintenance strategy fault tolerant mode and reliabilityanalysis for hydro power stations

Reliability analysis for hydro power stations for (N+M) and 2N fault tolerant modes (FTM) and their comparison from the standpoint of control and maintenance have been carried out in this paper. It shows that the (N+M) FTM is superior to 2N FTM in reliability and economics in most cases. So, (N+M) FTM is recommended for large power stations, especially for multi-unit plants. A simple method to choose the number of standby controllers is developed by optimizing the (N+M) FTM. The ideas and results proposed in this paper can be used not only for governing systems in hydro power stations but also for other industrial systems     

Variable structure and time-varying parameter control forhydroelectric generating unit

A variable-structure control strategy relative to the variable plant structure and output variation is developed, and a nonlinear compensation approach is proposed and analyzed. Moreover, for a certain plant structure with variable parameters a time-varying parameter control approach is developed, and its stability is analyzed and proved. Simulation results show the effectiveness of the proposed control strategy applied to an hydroelectric generating unit     

国外研究堆发展趋向

本文首先讨论了“倒中子陷阱原理”和辐射孔道反应堆设计与最优化的主要物理特性,并简介了格雷诺贝尔研究堆的设计实例。新颖的“紧凑堆芯”将用于西德慕尼黑研究堆 FRM 的改建中。