The Kalman-Yakubovich Lemma for non-stationary systems and its applications

An existence problem for non-stationary Lyapunov functions is considered. This problem is connected according to a certain rule with the linear Hamiltonian system that is called adjoint. We apply this method to obtain conditions of absolute stability and adaptive stabilization for non-linear non-stationary systems.     

Joint Optimization of Resource Allocation and User QoS Satisfaction Control for Efficient Grid Resource Management and Scheduling

This paper exploits the interlayer coupling of a cross-layer design concept in Grid computing environment. An algorithm for joint optimization of resource allocation and user quality-of-service (QoS) satisfaction control that combines both application-centric and system-centric scheduling benefits is proposed. The algorithm aims to maximize the global utility as well as the QoS is guaranteed. We formulate the problem into a constrained optimization problem. The simulations demonstrate the advantage of the proposed scheduling algorithm by comparing with application-centric and system-centric scheduling algorithm, respectively.      

多选择背包问题的知识进化算法

针对多选择背包问题,设计了求解该问题的知识进化算法方案,编写了仿真实验的程序,并采用其他文献的算例进行了仿真实验。结果表明该算法的有效性和优越性。本文为求解多选择背包问题提供了一种新的可行方法,同时也拓展了知识进化算法的应用领域。     

Shunt capacitor sizing for radial distribution feeders withdistorted substation voltages

An algorithm for optimizing shunt capacitor sizes on radial distribution lines with nonsinusoidal substation voltages such that the RMS voltages and their corresponding total harmonic distortion lie within prescribed values is presented. The problem is formulated as a combinatorial optimization problem with inequality constraints. A simple heuristic numerical algorithm that is based on the method of local variations is proposed to determine an optimal solution. An example shows that optimal capacitor sizes found by neglecting the harmonic components may result in unacceptable voltage distortion levels     

二次系统跨安全区数据传输方法及其在负荷预测中的应用

介绍了连云港地区电力二次系统跨安全区数据传输存在的问题,提出通过建立跨区数据传输与共享系统解决该类问题。分析了当前电力二次安全防护系统的结构和物理隔离装置数据传输的特点,以及如何设计封装各类通信协议进行数据交换和传输,并给出了在连云港地区负荷预测系统构建过程中应用跨区数据传输与共享的实例。     

CIM环境下PPCES的研究与实现

针对ＣＩＭ环境下单件小批量生产计划的“大设备平衡”这一核心问题,研究并实现了一种基于ＣＰＭ与专家经验相结合的ＰＰＣＥＳ专家系统。首先研究了求解这一问题的数学模型,约束条件和目标函数,设计了求解问题的专家系统解决方案,并与ＭＰＲⅡ实现了信息集成,最后给出了ＰＰＣＥＳ在典型单件小批制造业哈尔滨电机厂ＨＥＣ－ＣＩＭＳ工程中运行实例,结果表明本系统能方便、灵活地处理生产计划的“大设备平衡”这一核心问题,有     

遗传算法在复杂系统可靠度最优分配中的应用

复杂系统可靠度最优分配问题是一个具有多局部极值的非线性的优化问题,使用遗传算法求解该问题搜索到其他算法未能得到全局或次优最优解,在遗传算法的应用中,使用基于排名的选择策略和最成保存策略,改善了遗传算法的收敛性能。     

机组组合问题的仿射可调整鲁棒优化模型与算法

为了有效应对电力系统调度决策中的不确定因素,尤其是大规模间歇式能源并网所带来的不确定性,提出基于仿射可调整鲁棒优化理论的不确定机组组合求解方法。建立了不确定机组组合问题的仿射可调整鲁棒优化模型,利用线性决策规则建立决策变量与不确定参数之间的仿射关系,从而将两阶段问题转化为单个阶段优化问题,在此基础上,采用对偶理论将模型转化为可以直接求解的标准混合整数规划模型。通过标准算例测试,验证了该方法的有效性。     

系统分解协调算法的抽水蓄能电站优化调度

建立了包含抽水蓄能电站的电网统一调度优化模型,即以调度周期内火电燃料成本为最小目标函数,满足系统及各机组约束条件。利用系统分解协调思想,开发了一个结合拉格朗日松弛方法和粒子群优化算法的混合算法,将原优化问题分解为两层优化问题。上层拉格朗日算子优化利用次梯度算法求解,下层各子问题利用粒子群优化算法求解,经过迭代寻优得到最优对偶解后,利用一个启发式算法求得满足系统约束及各机组运行约束的原问题的可行解。最后通过算例验证了模型的合理性及算法的有效性。     

Telephone cable: overview and dielectric challenges

An overview of the common types of telephone wire and cable used in the United States and of related industry specifications is provided. Common insulating materials and selected electrical and physical parameters are discussed, along with several dielectric-related problems facing the industry. One is to reduce the migration of oil from cable filling gels into the insulation, where it adversely affects the electrical and physical properties. A second problem is how to reduce the overall fire hazard contributed by wire and cable installed in a building. A third problem is to develop twisted-pair copper cables that can handle increasingly higher data rates     

Application of robust and adaptive pole placement

The previous investigation showed the usefulness of a two-degree-of-freedom configuration. Such a controller can also be designed using pole placement. An adaptive controller based on this concept is developed and applied to the problem with good results. Particular features, such as selection of model structure, design parameters and excitation, are also discussed.     

New approximate optimization method for distribution systemplanning

An algorithm to obtain an approximate optimal solution to the problem of large-scale radial distribution system planning is proposed. The distribution planning problem is formulated as a MIP (mixed integer programming) problem. The set of constraints is reduced to a set of continuous variable linear equations by using the fact that the basis of the simplex tableau consists of the power flow variables of radial branch. This linear problem is solved by pivot operations which correspond to a branch-exchange of the radial network. Numerical examples are presented to demonstrate the validity and effectiveness of the algorithm     

PLC热备系统及其应用

通过分析AB公司PLC热备系统的硬件结构和工作原理 ,解释热备系统发生切换时出现输出跳变和存在数据不完整现象的原因 ,给出利用高速串行链路进行热备编程而解决这一问题的方法 ,并介绍了应用于大型高炉鼓风机监控中的实例     

格林函数法在电磁层析成像技术中的应用

EMT的逆问题求解很困难但也是必要的,采用格林函数法可以得到表示EMT多层媒质传感系统逆问题的积分式。合理忽略某些媒质层,可以得到简化了的逆问题的积分表达式,从而可构造图像重建算法,并得到了较好的重建结果。     

改进二进制粒子群优化算法在配电网络重构中的应用

配电网络重构是一个非常复杂的大规模组合优化问题。网络重构中,能否得到有效解,即保证辐射状网络,是一个很关键的问题。对电网拓扑进行简化,配合破圈法更新粒子,得到100％的有效解,大大提高了计算速度。提出一种应用于配电网络重构的改进二进制粒子群优化算法,并结合禁忌搜索算法,使PSO算法跳出局部最优化陷阱,改善了算法的搜索效果,加快了寻优速度。最后对IEEE 69节点系统进行计算,并与相关文献结果进行对比,表明本文改进算法具有快速、高效的全局寻优能力。     

Binary-Representation-Based Genetic Algorithm for Aircraft Arrival Sequencing and Scheduling

Arrival sequencing and scheduling (ASS) at airports is an NP-hard problem. Much effort has been made to use permutation-representation-based genetic algorithms (GAs) to tackle this problem, whereas this paper attempts to design an efficient GA based on a binary representation of arriving queues. Rather than using the order and/or arriving time of each aircraft in the queue to construct chromosomes for GAs, this paper uses the neighboring relationship between each pair of aircraft, and the resulted chromosome is a 0-1-valued matrix. A big advantage of this binary representation is a highly efficient uniform crossover operator, which is normally not applicable to those permutation representations. The strategy of receding horizon control (RHC) is also integrated into the new GA to attack the dynamic ASS problem. An extensive comparative simulation study shows that the binary-representation-based GA outperforms the permutation-representation-based GA.     

Starting processes in the frequency-regulated asynchronous drive during optimal control

The problem of the definition of optimal control of an induction motor in dynamic regimes is considered. The method of genetic algorithms is proposed for the solution of the problem. An example of application of this method for organizing the starting process of an induction motor with a squirrel cage is examined.     

PG9171E型燃气轮机启动失败后相关事故的分析和预防

对PG9171E型燃气轮机一次启动失败跳闸后仍有燃油燃烧的问题进行分析,并提出了一些相应的处理方案和预防措施。     

Understanding and measuring iridescence (spectral banding) ofanodized luminaire surfaces

Iridescence is a problem of increasing concern since the introduction of narrowband lamps and anodized luminaire surfaces. It appears as induced coloration of luminaire surfaces, much like rainbow patterns associated with thin oil or soap films on water. The causes of the effect are discussed, and an interim color measurement method based on standard CIE (1986) and ASTM (1987) practices for the measurement of color in terms of the human visual system is proposed. An analysis of the nature of the effect is provided so that the problem at hand can be better managed and understood