基于系统可靠性的主动配电网置信容量评估

评估主动配电网的置信容量,可以充分利用新能源,为主动配电网的优化配置提供有效参考。以新增电源的有效载荷能力表征主动配电网的置信容量,建立基于等可靠性指标的评估模型。在蒙特卡..

考虑分布式再生能源和储能的主动配电网可靠性评估

随着主动配电网技术的逐步发展和应用,针对主动配电网的各项评估技术也需要进一步研究。由于主动配电网在网络结构、潮流流向等方面与传统配电网有很大区别,因此针对主动配电网的评估方法也与传统配电网不同,提出了一种考虑分布式再生能源和储能的主动配电网可靠性评估方法。首先运用蒙特卡洛模拟法进行系统状态选择,再基于不同网络类型,采用改进的前推回代潮流计算方法进行潮流计算与潮流平衡调整,进而计算各项评估指标,获取综合评估值。通过对9个方案进行可靠性评估,验证了所提方法的有效性

基于并行小种群差分进化算法的水火电力系统短期优化调度

为解决水火电力系统短期发电优化调度中存在的问题,提出基于MPI平台的并行小种群差分进化算法。该算法将进化种群分为若干个小种群(单个种群规模为3~10个),每个进化种群由不同的CPU进程独立执行差分进化算法,并在种群间引入集合、分散操作以协调各小种群的寻优过程;为降低小种群初始化和进化过程中多样性的损失,引入正交化初始化方法和种群重构技术;最后以典型案例验证了算法的有效性。结果表明,该方法在求解精度、收敛速度和求解耗时上均较有竞争力。国家自然科学基金项目(61403321);;广东省自然科学基金项目(2014A030310003

Effects of Lanthanum on Redox Systems in Plasma Membranes of Casuarina equisetifolia Seedlings Under Acid Rain Stress

The effects of La3 + on the growth and the ATPases activities of plasma membrane (PM) vesicles isolated from Casuarina equisetifolia seedlings under artificial acid rain (pH 4. 5) stress were studied. The results show that the height , length of roots , fresh weight and PM H+2ATPase activites of Casuarina equisetifolia seedlings increase by the treatments of soaking seeds in LaCl3 solutions with lower concentrations , and those can reach their peak values by treating with 200 mg ·L - 1 La3 + . However , in comparison with the CK, those are inhibited by the higher La3 + concentrations ; PM Ca2 +2AT2 Pase activity is inhibited with the treatments of La3 + . The results also reveal that the H+2ATPase activity and the growth of cell enlarge have a remarkable positive correlation , and La3 + activating H+2ATPase can facilitate plant growth. La3 + al2 so can alleviate cytosolic acidification of plant under acid rain stress and indirectly maintain the stability of intracellular environment . In order to resistant to acid rain and accelerate the growth of Casuarina equisetifolia , the suitable range of La3 + concentrations to soak seeds for 8 h is 50～200 mg·L - 1

主动配电网规划方案经济性综合评估方法探析

在同一配电网的网络结构下,利用风光储容量不同和接入的节点不同形成多个主动配电网规划方案,这些方案之间的经济性差异明显,然而低分布式能源占比的传统配电网经济性评估方法难以对高分布式能源占比的主动配电网的经济性进行评估。现从主动配电网的特性出发,建立了包括总净值、分布式电源、综合资源利用率、线损率、电网资产利用率等经济性的综合评价指标体系,给出了各个指标的数学模型和综合得分值的获取方法,以此来判断不同方案的经济性优劣

A modified chaotic differential evolution algorithm for short-term optimal hydrothermal scheduling

The short-term optimal hydrothermal scheduling (STOHS) plays one of the most important roles in power systems operation. The STOHS problem involves the solution of difficult constrained optimization problems that require good computational techniques. This paper proposes a modified chaotic differential evolution (MCDE) approach for the solution of this difficult optimization problem. A repair strategy and a novel selection operation are simultaneously introduced into the MCDE approach for handling constraints of the problem. The repair strategy preserves the feasibility of solutions generated and avoids the use of penalty factors as much as possible. The introduced selection operation makes a not clearly distinction between feasible solutions and infeasible ones at early stage of the algorithm and makes a clearly distinction at the later stage. Additionally, an adaptive regeneration operation is proposed to enhance population diversity and to avoid local optimums. Moreover, a chaotic local search technique is introduced also to accelerate the searching process of the algorithm. The proposed MCDE approach is applied to three well-known hydrothermal test systems in order to verify its feasibility and efficiency. The obtained results are compared with those obtained by other population-based heuristic approaches reported in literature. It is observed from the comparisons that the proposed MCDE approach performs effectively and can yield competitive solutions. ? 2014 Elsevier Ltd. All rights reserved

Short-term hydrothermal scheduling considering valve point effect using acceleration-based PSO algorithm

Short-term hydrothermal scheduling (STHS) is one of the important optimization problems in power systems. A mathematical model considering various constraints is established to minimize the total thermal fuel cost in the STHS problem. To solve this problem, an acceleration-based particle swarm optimization (APSO) approach is proposed. In the proposed approach, an adaptive mutation operation is introduced to enhance the swarm diversity; a differential evolutionary (DE) algorithm is employed as an acceleration operation to speed the convergence rate; a novel inertia weight design mechanism is developed to balance global exploration and local search of the APSO algorithm; a repair strategy on equality constraints of the problem is proposed to avoid penalty function approach as much as possible. Three hydrothermal test cases in literature are considered to compare the results obtained by the proposed approach with other population-based algorithms. Two other particle swarm optimization (PSO) versions are also implemented on the same cases to compare the detailed statistic properties of them with the proposed one

Anti-collision Algorithm Based on EPC Class-1 Gen-2 Standard and Its Improvement

针对RFID读写器识别多标签过程中出现的冲突问题,研究并实现了EPC Class-1 Gen-2标准中的防冲突算法,即时隙随机算法(SR算法),同时针对SR算法的不足提出改进算法。改进算法采用不避让冲突时隙的处理方式,降低了由时隙的随机选取所导致的标签间冲突的概率。实验结果证明,改进后的算法在通信次数和吞吐率方面均优于原算法,有效提高标签识别效率

考虑电网络影响的水火电力系统短期优化调度

为提高发电计划实际执行的可行性,提出考虑电网络影响的水火电力系统短期优化调度方案,即在传统水火电优化调度中引入输电网络潮流约束,构建水火电力系统短期优化调度数学模型。该模型以火电站的总煤耗量最小为优化目标,考虑水火电的发电特性、梯级水电复杂关系、系统运行约束、输电网络约束及传输功率限制。同时为模型求解引入迁徙操作和惯性权重非线性递减策略的改进粒子群算法,并设计了五种约束处理规则以应对复杂的约束条件。最后以典型水火电系统和IEEE-9节点的电网络拓扑为例对所构建的模型和算法进行验证。结果表明,所构建的优化模型和设计的求解方法能满足复杂运行约束的短期调度方案。国家自然科学基金项目(61403321);;四川省电力公司科技项目(川电发展[2016]13号文