分布式可再生能源发电并网的无功优化研究

提出了基于杂交粒子群优化算法的分布式可再生能源并网的无功优化算法,从网损和静态电压稳定裕度两个角度出发,构建了含分布式发电系统的配电网无功优化的数学模型.在美国PG&E 69节点配电系统上进行效验.结果表明,该算法收敛性好、精度高;分布式电源并网后能有效降低系统的有功网损,提高电压稳定性,对分布式电源并网运行具有一定的...     

基于遗传算法的超级电容RTG能量管理研究

为提高超级电容混合动力轮胎式集装箱门式起重机(Rubber Typed Gantry, RTG)系统的能量利用率和燃油的经济性,需要对混合动力能量系统进行有效的管理。提出了一种考虑系统能耗和非再生能量因素情况下,能分别确定混合动力系统中柴油发电机组最优输出功率和超级电容器组的最优输出功率的优化方法。建立了柴油发动机组和超级电容器组的数学模型。根据混合动力RTG关键特性参数和负载需求值,得出了负载需求曲线图。考虑发电机组燃油消耗的能量、来自电容器组的能量贡献和产生的非再生能量,构造了整体能耗的成本函数。并引入遗传算法(Genetic Algorithm, GA)进行求解,最后进行仿真和对比分析。结果表明,与传统的基于规则的控制策略相比,遗传算法优化后的能量管理系统,其能量消耗减少了35.9%。     

Self-balancing dynamic scheduling of electrical energy for energy-intensive enterprises

Balancing production and consumption with self-generation capacity in energy-intensive enterprises has huge economic and environmental benefits. However, balancing production and consumption with self-generation capacity is a challenging task since the energy production and consumption must be balanced in real time with the criteria specified by power grid. In this article, a mathematical model for minimising the production cost with exactly realisable energy delivery schedule is formulated. And a dynamic programming (DP)-based self-balancing dynamic scheduling algorithm is developed to obtain the complete solution set for such a multiple optimal solutions problem. For each stage, a set of conditions are established to determine whether a feasible control trajectory exists. The state space under these conditions is partitioned into subsets and each subset is viewed as an aggregate state, the cost-to-go function is then expressed as a function of initial and terminal generation levels of each stage and is proved to be a staircase function with finite steps. This avoids the calculation of the cost-to-go of every state to resolve the issue of dimensionality in DP algorithm. In the backward sweep process of the algorithm, an optimal policy is determined to maximise the realisability of energy delivery schedule across the entire time horizon. And then in the forward sweep process, the feasible region of the optimal policy with the initial and terminal state at each stage is identified. Different feasible control trajectories can be identified based on the region; therefore, optimising for the feasible control trajectory is performed based on the region with economic and reliability objectives taken into account.     

基于序列二次规划法的分布式电源优化配置研究

针对分布式电源配置对配电网的影响,提出一种带二阶项配网潮流约束的方法解决分布式电源优化配置问题,以实现分布式电源价值的最大化。从降损角度出发建立优化配置的数学模型,并用序列二次规划求解优化问题。在充分发挥序列二次规划法收敛性好的基础上,提高计算精度,并适用于各种复杂的配电网络。以IEEE33节点系统为例,验证所提方法在分布式电源优化配置问题求解中具有很强的全局搜索能力,可以有效、准确地实现分布式电源的最优配置,计算过程简单可靠,具有实用价值。     

混杂系统优化控制的动态规划方法研究

研究了末态自由、时间一定的混杂系统的最优控制问题. 提出了基于可达网络的混杂系统优化控制的动态规划方法. 这种方法能够给出问题的全局最优解, 并有效地降低系统的计算量.     

浅谈分布式光伏发电

分布式光伏发电作为新型能源,在未来发展具有很广阔的前景。文章结合目前分布式光伏发电实际发展情况,介绍了光伏发电原理、光伏电源对配电网的影响及系统保护配置等,并具体介绍了分布式发电并网调度管理的运行步骤。     

基于异步动态事件触发通信策略的综合能源系统分布式协同优化运行方法

研究综合能源系统的协同能源管理问题,并提出了一种基于异步动态事件触发通信策略的分布式梯度算法来解决该问题.通过引入外部辅助变量并设计有效的触发机制,该方法可以使得每个参与者仅在必要时刻以离散且异步的方式与邻居产生通信交互,实现了连续通信的离散替代化.同时,该方法并不要求全局同步时钟,具有更强的灵活性.此外,本文也在理论上证明了算法的全局收敛性.最后,仿真结果验证了所提方法的有效性.     

A decoupled controller for fuel cell hybrid electric power split

The power management of a hybrid system composed of a fuel cell, a battery and a DC/DC power converter is developed. A decoupled control strategy is proposed, aimed at balancing the power flow between the stack and the battery and avoiding electrochemical damage due to low oxygen concentration in the fuel cell cathode. The controller is composed of two components. The first controller regulates the compressor, and as consequence the oxygen supplied to the cathode, via a classic proportional–integral controller. The second controller optimally manages the current demanded by the fuel cell and battery via linear-quadratic control strategy acting on the converter. The closed-loop performance has been tested both in simulation and in real-time simulation using a microprocessor for the controller.     

基于混合遗传算法的矿井排水系统优化

针对井下排水系统水泵开机的不确定性和不规律性造成耗电量过大的问题,提出一种以排水系统最小能耗为目标函数的优化调度模型,利用混合遗传算法寻找最优解。仿真结果表明,该方法能够有效避免遗传算法容易出现的早熟现象,提高局部寻优能力,具有较强的适用性。排水系统的平均节能效率达到6.5%以上。     

操作系统电源管理研究进展

系统级动态电源管理技术的关键问题是在系统性能与能耗之间进行权衡. 在硬件提供支持的基础上,操作系统电源管理的优势在于操作系统作为系统资源管理者,根据工作负载和硬件资源电源状态的特征,在满足系统性能约束条件下作出电源管理决策和控制,降低系统能耗. 从优化控制策略和操作系统资源管理的角度,综述操作系统电源管理研究现状及其关键技术. 对两类动态电源管理策略进行详细分析,讨论了从资源管理角度进行操作系统电源管理的研究思路和问题,对当前面临的主要问题和发展趋势进行了总结和展望.     

Improving Resource Management in Distributed Systems using Language-Level Structuring Concepts

Currently, a shift of paradigm from sequential to distributed computing can be observed. Tremendous efforts are needed to cope with the challenging demands that are inherent to this transition. The two most important issues concern programming support for developing large-scale distributed applications and the efficient execution of such applications on top of a distributed hardware configuration. This paper presents a new language and object-based approach called MoDiS to cope with these demands. Distributed systems are developed and transformed into executables following a systematic, top-down driven method. Language-level is intended to mean that a high-level programming language is used to develop operating system services as well as user-level applications. The language-level concepts employed are based on objects and support advanced structuring features. Structural dependencies between objects are implicitly determined at the application level and exploited by the distributed resource management system to transform applications into efficient executables.     

基于改进量子差分进化的含分布式电源的配电网无功优化

差分进化算法（DE）已被证明为解决无功优化问题的有效方法.随着越来越多的分布式电源并网,对配电网潮流、电压均有一定改变,同时也影响了DE的鲁棒性和性能.本文在研究DE基础上,针对其收敛过早、局部搜索能力较差的缺陷,分析了量子计算思想和人工蜂群算法的优势,提出改进量子差分进化混合算法（IQDE）.通过量子编码思想提高了种群个体的多样性,人工蜂群算法的观察蜂加速进化操作和侦查蜂随机搜索操作分别提高了算法的局部搜索和全局搜索性能.建立以有功网损最小为目标的数学模型,将IQDE算法和DE算法分别用于14节点和30节点标准数据集进行大量仿真实验.实验结果表明,IQDE算法用更少的收敛时间、更小的种群规模便可以获得与DE算法相同甚至更佳的优化效果,并且可以很好的应用于解决难分布式电源的配电网无功优化问题.     

基于分布式中间件的电力监控系统设计与实现

基于对象的分布式计算技术是当今计算机软件开发的所采用的一种重要技术.与传统开发技术相比,分布式对象技术具有更好的开放性和扩展性.基于对象的中间件是分布式对象技术的良好应用.结合能量管理系统的需要,在分布式对象互操作思想的基础上,对电力监控系统中所采用的分布式中间件技术进行了设计与分析,对电力监控系统中的中间件技术的组织模式、系统流程及实现模式进行了设计,应用cORBA中间件技术对其进行了实现,并在某智能配电自动化有限公司得到了相应的应用.     

Question-asking strategies for Horn clause systems

An expert system applies the deduction rules in its knowledge base to a set of initial data to reach a conclusion. When the initial data are insufficient, the expert system may ask the user for additional information. This paper analyzes effectiveness and efficiency of question-asking strategies in expert systems with Horn clause knowledge bases. An effective strategy reaches a conclusion after asking as few questions as possible. An efficient strategy can be computed quickly. We prove that effective strategies are, unfortunately, not efficient. However, we present a somewhat less effective but very efficient strategy. It employs an algorithm which simultaneously performs deduction and question selection in log-linear time.Supported in part by NSF grant DMS-8513970.