基于统一潮流控制器的柔性交流输电系统的控制

本文提出一种具有统一潮流控制器的柔性交流输电系统的控制方法。控制系统由静态控制和暂态控制组成，其中静态控制用于系统正常工作状态的潮流调节，动态控制是根据暂态能量最小方法设计的，用于增加系统受扰后的振荡阻尼，以提高系统暂态稳定性，数字仿真的结果数量，这种控制系统和控制方法是可行的，而且有效的。     

Development of a Fuzzy Rule-Based Multi-Objective Hybrid Controller for Static Synchronous Compensator

Static synchronous compensator (Statcom) is a powerful new device for power systems, which can be used for various purposes. The multi-objective demands are quite different in nature, e.g. continuous linear control for voltage maintaining, and discrete bang-bang control for oscillation damping. Unfortunately, they often conflict with each other. In this respect, a supplementary damping control together with an independent voltage control is normally used. However, inevitable small disturbance and uncertainties will cause problems in the coordination of the two functions. To overcome such difficulties, a fuzzy rule-based hybrid controller is proposed in this paper, which incorporates conventional linear voltage control along with the fuzzy rule-based supplementary power damping control to form a unified global controller for Statcom. Because only simple fuzzy rules and a few input signals are involved, it is very easy to implement in a practical power system. The simulation performed on a Single- Machine-Infinite-Bus (SMIB) power system and an actual large power system demonstrates the effectiveness of the proposed approach.     

一种评价多个直流换流站系统次同步扭振相互作用的新指标

系统中的汽轮发电机组可以通过网络同时与多个直流换流站发生作用，因此其次同步振荡问题更为复杂。为了研究由多个直流换流站引起的次同步振荡问题，该文将描述发电机组与单个换流站之间扭转作用的机组作用系数(UIF)推广到含有多个直流换流站的系统，提出了综合机组作用系数(CUIF）这一指标，即采用系统中所有直流换流站的机组作用系数之和来量化其与发电机之间的扭振相互作用。并通过系统电气阻尼频率特性的仿真计算证明了综合机组作用系数在各种系统结构下的有效性。     

Estimation of valve stiction in control loops using separable least-squares and global search algorithms

This contribution presents a new procedure for quantifying valve stiction in control loops based on global optimisation. Measurements of the controlled variable (PV) and controller output (OP) are used to estimate the parameters of a Hammerstein system, consisting of a connection of a two-parameter stiction model and a linear low-order process model. As the objective function is non-smooth, gradient-free optimisation algorithms, i.e., pattern search (PS) methods or genetic algorithms (GA), are used for fixing the global minimum of the parameters of the stiction model, subordinated with a least-squares estimator for identifying the linear model parameters. Some approaches for selecting the model structure of the linear model part are discussed. Results show that this novel optimisation-based technique recovers accurate and reliable estimates of the stiction model parameters, dead-band plus stick band (S) and slip jump (J), from normal (closed-loop) operating data for self-regulating and integrating processes. The robustness of the proposed approach was proven considering a range of test conditions including different process types, controller settings and measurement noise. Numerous simulation and industrial case studies are described to demonstrate the applicability of the presented techniques for different loops and for different amounts of stiction.     

升压直流电能收集充电器

该电能收集充电器采用基于ARM？CortexTM—M3的LM3S1138微控制器,它为嵌入武微控制器应用方案带来了高性能的32位运算能力。该系统主要由硬件来实现,通过boost电路实现直流电压之间的转换和提升并完成直流电源变换器的功能。LM3S1138内置的10位A／D转换器能够实现精确采样以监测电压的微小变化,并通过LCD液晶显示屏显示,其界面友好,性能优良。应用软件则主要完成系统监测和控制。它全部采用C语言编程,实现基本监测、控制和输出功能,并可收集微弱输入电压或通常电压对不同的电池充电,同时还具有超时报警等功能。该系统资源丰富,还可方便地扩展其附加功能。     

具有连续变量和正负系数的差分方程的振动性及强迫振动性

本文给出了一类具有连续变量和正负系数的线性差分方程振动及强迫振动的充分条件，所得结果是新的。     

Linearized oscillations of first-order nonlinear neutral delay difference equations

In this paper, we establish an equivalence of oscillation for the first-order nonlinear neutral delay difference equation

and its corresponding linear equation

under weaker conditions on f_i.     

振动技术在注射成型中的应用

介绍了振动技术在汪射成型中的应用,描述了模腔内振动剪切流动作用机理。实验研究表明,通过振动的作秀能提高注射制品的拉伸强度,利用螺杆振动技术而制备的ＰＰ,ＨＤＰＥ和ＰＳ注射制品的拉伸强度分别提高１８．３％２２％和１６％。     

Improvement of combustion efficiency and reduction of NO x emission by external oscillation of reactants in an oil burner

The important requirement for the development of burners is the achievement of low emissions, particularly NO _x , while maintaining high combustion efficiency. In this work, an externally oscillated oil burner was developed which provides both high-efficiency combustion and low NO _x emission simultaneously. To investigate combustion characteristics and NO _x emission, parametric studies were carried out about oscillation frequency, forcing amplitude, and air velocity. Optimum combustion was achieved at frequency of 1,900 Hz, amplitude of 3 V _pp , and air velocity of 6.8 m/s. The NO _x and CO emissions were reduced by 47% and 22%, respectively. In particular, the mechanism responsible for the inherently low NO _x emission levels from an externally oscillated oil burner has been shown to be a short residence time at high temperature caused by rapid mixing with cooler residual gases.     

压电驱动微泵泵膜振动有限元分析

以压电驱动微泵泵膜为研究对象,分析了压电复合泵膜膜片的弹性曲面微分方程,建立了泵膜膜片有限元数值模拟的模型,对泵模膜态进行了计算和分析,模拟并分析了驱动电压、泵膜压电层半径与泵膜单晶硅层半径之比、单晶硅层厚度、压电层厚度对泵膜位移的影响。所作研究为压电驱动微泵的优化设计提供了理论依据。