南方电网抽水蓄能电站自动发电控制功能研究与应用

抽水蓄能电站自动发电控制功能是电站的核心控制功能,抽水蓄能电站工况复杂,具备水泵、调相等特殊工况,其自动发电控制逻辑较常规电站复杂。本文以南方电网所辖的各抽水蓄能电站为例,详细介绍了南方电网抽水蓄能电站自动发电控制功能的主要控制算法,包括发电工况成组控制、抽水工况成组启动控制算法等,为抽水蓄能电站自动发电控制功能设计提供参考。     

多元共聚自交联丙烯酸酯乳液的合成与应用研究

在丙烯酸酯乳液共聚反应中,引入二种以上活性基团,合成的自交联型乳液胶可用于聚酰亚胶与铜箔的粘接。本文对乳液的合成条件,使用工艺进行了探索,对共聚反应用的丙烯酸酯等软硬单体用量的比例、交联单体加入量进行了研究,由此得到的新型丙烯酸酯胶无需二次复配即可直接使用,用于柔性印刷电路（FIPC）基材压制时,可赋于基材以优良的使用性能。     

The splitting tendency of uniaxially-oriented PET tapes investigated with nano-indentation,nano-scratch,differential scanning calorimetry,and X-ray

Earlier, various additives werescreened to improve the weavability of poly(ethylene terephthalate) (PET) tape. For predicting the weavability, three tests had been used: tensile impact strength, fibrillar versus puckered fracture and an axial folding test. This paper shows the possibility of using a simple nano-indentation method to decide on the splintering tendency of uniaxially-oriented PET tapes, as a predictor for weavability. A plasticity index derived from the nano-indentation correlated with PET tapes that were, or were not, weavable. Nano-scratches applied parallel and perpendicular to the tape also showed differences that could be correlated to the splitting tendency. While investigating these tests methods, it was observed that pure uniaxially- oriented PET tape heat set at 140°C had a non-splintering character even without additives, while polymeric additives were needed to resist splintering for the tape heat set at 240°C. Calorimetry showed no difference in heat-of-fusion implying identical crystallinity in the tapes heat set at 140°C and 240°C. However, X-ray studies revealed that the crystallites in the tape heat set at 140°C were smaller/and or imperfect, and hence there were more lateral tie-molecules that provided it the splitting resistance. Pure PET tape if heat set below 150°C may be a workable solution for weaving, thereby dispensing with the need for toughening additives.     

基于ACPI的风力发电系统MPPT控制方法

针对直驱永磁同步风力发电系统存在非线性、参数不确定性以及转矩扰动等问题,研究了一种基于自耦PI控制理论的最大功率跟踪控制方法。该方法以转速跟踪为目标,将发电机内部动态与外部输入转矩的不确定性定义为一个总和扰动,从而将非线性不确定系统映射为未知线性系统,并构建了一个在总和扰动反相激励下的受控误差系统。据此设计了基于误差速度因子的自耦PI控制器模型,理论分析了自耦PI闭环控制系统的鲁棒稳定性和抗扰鲁棒性。仿真结果表明了该控制方法能稳定保持最大功率系数,在风力发电系统的最大功率跟踪领域具有良好的应用前景。     

基于改进果蝇算法优化的微电网逆变器恒功率控制算法

针对微电网逆变器恒功率控制器PI参数优化的问题,提出了基于种群分区的多策略自适应果蝇(ppmaFOA)优化的PI参数在线优化算法。根据适应度值进行排序将果蝇种群分为三个区,因每个区果蝇性能的差异提出多策略更新模式：I区局部精细搜索保证种群不退化,II区根据算法所处环境自适应调节算法的多样性和收敛性,III区引导果蝇加速收敛,提高了算法的开发和探索能力。采用5种对比算法,利用微电网恒功率控制系统进行实验,验证了所提算法的性能和经ppmaFOA算法优化后逆变器的响应速度更快、误差更小、输出更稳定。     

电网电压不平衡条件下MMC控制策略的仿真比较研究

当电网电压不平衡时,交流侧的电流会出现不对称,有功功率和无功功率在模块化多电平变流器(MMC)外部出现二次波动,严重影响系统的稳定性和电源质量。因此,在电网电压不平衡条件下控制MMC是非常必要的。针对电网电压不平衡状态下的MMC交流侧三相电流不对称、有功功率二次脉动、无功功率二次脉动问题,对这3种控制目标下的参考电流分别进行了求解,并制定了传统PI控制、滑模控制、无源控制等控制策略。最后,在MATLAB/Simulink平台上仿真并比较3种控制策略的优缺点。     

Compatibilizing effect of poly(styrene)‐block‐poly(isoprene) copolymers in heterogeneous poly(styrene)/natural rubber blends

Compatibility of poly(styrene) (PS)/natural rubber (NR) blend is improved by the addition of diblock copolymer of poly(styrene) and cis‐poly(isoprene) (PS‐b‐PI). The compatibilizing effect has been investigated as a function of block copolymer molecular weight, composition and concentration. The effect of homopolymer molecular weight, processing conditions and mode of addition on the morphology of the dispersed phase have also been investigated by means of optical microscopy and scanning electron microscopy. A sharp decrease in phase dimensions is observed with the addition of a few percent of block copolymers. The effect levels off at higher concentrations. The leveling off could be an indication of interfacial saturation. For concentrations below the critical value, the particle size reduction is linear with copolymer volume fraction and agrees well with the prediction of Noolandi and Hong. The addition of the block copolymer improves the mechanical properties of the blend. An attempt is made to correlate the mechanical properties with the morphology of the blends. © 2001 Society of Chemical Industry     

PTEN and Other PtdIns(3,4,5)P3 Lipid Phosphatases in Breast Cancer

The phosphoinositide 3-kinase (PI3K)/AKT signalling pathway is hyperactivated in ~70% of breast cancers. Class I PI3K generates PtdIns(3,4,5)P₃ at the plasma membrane in response to growth factor stimulation, leading to AKT activation to drive cell proliferation, survival and migration. PTEN negatively regulates PI3K/AKT signalling by dephosphorylating PtdIns(3,4,5)P₃ to form PtdIns(4,5)P₂. PtdIns(3,4,5)P₃ can also be hydrolysed by the inositol polyphosphate 5-phosphatases (5-phosphatases) to produce PtdIns(3,4)P₂. Interestingly, while PTEN is a bona fide tumour suppressor and is frequently mutated/lost in breast cancer, 5-phosphatases such as PIPP, SHIP2 and SYNJ2, have demonstrated more diverse roles in regulating mammary tumourigenesis. Reduced PIPP expression is associated with triple negative breast cancers and reduced relapse-free and overall survival. Although PIPP depletion enhances AKT phosphorylation and supports tumour growth, this also inhibits cell migration and metastasis in vivo, in a breast cancer oncogene-driven murine model. Paradoxically, SHIP2 and SYNJ2 are increased in primary breast tumours, which correlates with invasive disease and reduced survival. SHIP2 or SYNJ2 overexpression promotes breast tumourigenesis via AKT-dependent and independent mechanisms. This review will discuss how PTEN, PIPP, SHIP2 and SYNJ2 distinctly regulate multiple functional targets, and the mechanisms by which dysregulation of these distinct phosphoinositide phosphatases differentially affect breast cancer progression.     

基于二自由度PI控制器的吹塑机张力控制系统

吹塑机的张力控制系统是一个大时滞线性系统,实现其控制难度较大。针对张力控制系统的一阶积分时滞模型,提出一种改进的基于多主导极点配置方法的二自由度PI控制算法,假设存在正的、稳定的多主导极点,过程控制系统无振荡,并且非主导的极点和零点对控制过程无影响,为了提高伺服性能和降低超调量,在结构中设计了设定点滤波器。仿真案例实验结果表明,该方法在吹塑机张力控制中具有良好的追踪性能和扰动抑制性能。