分布式可再生能源的广泛接入对配电网的规划与运行产生重大影响,如何准确评估配电网的最大并网能力是一个配电网规划中的重要问题。该问题的最大挑战是在评估模型中如何刻画分布式电源出力的不确定性,并进行有效求解。为此,提出了一种基于机会约束的配电网分布式电源容量评估方法。该方法考虑了分布式电源出力及负荷预测的不确定性,将约束构建为线性机会约束形式。通过假设预测误差服从各个变量的边际分布相互独立、均值为0的概率分布,进一步将该机会约束模型转化为可被有效求解的混合二阶锥规划模型。最后,基于IEEE 33节点配电网络的算例给出了所提出方法的评估结果。基于文中提出的分布式电源容量评估方法在给定约束越限概率下可得到较大容量的接入方案。

基于电压源型换流器的多端直流输电电网是解决可再生能源并网和消纳的有效途径,因此研究交直流混合电网的潮流算法很有必要。提出了一种基于扩展节点法的交直流混合电网统一潮流算法。首先建立了电压源型换流站的稳态模型和控制策略及基于扩展节点法的交流和直流电网的网络模型。然后推导了基于牛顿法的统一潮流算法,将交直流混合电网的节点注入电流、支路电流和节点电压作为未知变量同时求解。通过IEEE 30节点交直流混合电网算例验证了所提算法的有效性。

A non-revisited NSGA-II algorithm, which integrates BSP (binary space partitioning)-based non-revisiting mechanism and the non-dominated sorting genetic algorithm-II (NSGA-II) based on the ideology of multi-objective Pareto optimization, is constructed and is then used to solve the problem of distribution networks multi-objective reconfiguration with the consideration of loss minimization and the improvement of reliability. The proposed algorithm achieves a strictly non-revisited research, which avoids the recalculation of power flow and reliability of revisited schemes and saves the computing resources. The test results of IEEE 16-bus and IEEE 33-bus sample systems indicate that the proposed method can obtain the optimal solution in every target direction as well as an optimal Pareto frontier aggregates including a lot of non-dominated solutions in less iterations. According to incidence relations between network losses and reliability goals, along with the topology construction analysis of corresponding reconfiguration schemes, conclusions can be drawn that network losses are in apparent consistency with reliability goals in global scope of solution space, and whether out of the consideration of network loss optimization or reliability optimization, the topology of networks should be close to breadth-first tree rather than depth-first tree.

根据光伏电池的内部结构建立其等效电路图,在MATLAB/Simulink的环境下建立光伏电池的仿真模型,并对不同温度和光照强度下光佚电池的输出特性进行了仿真.同时,对光伏电池在不同条件下的输出特性进行了分析.基于光伏电池仿真模型的基础上利用模糊控制的方法对于光伏系统最大功率点跟踪进行了仿真研究,仿真结果验证了模糊控制在处理光伏系统这种非线性系统时有很强的优势.

In order to improve the conversion efficiency of the photovoltaic power generation system,a detailed analysis of the buck,boost,buck-converter circuit circuit structure and working principle.Created in MATLAB/Simulink environment by three equivalent circuit diagram of the circuit,the three circuit simulation model,calculated through simulation output to compare their level of conversion efficiency,and ultimately determine one as a photovoltaic power generation system the DCDC converter circuit.

<正>一份规划的出台让江西近日成了媒体关注的热点区域。11月7日,《江西省光伏产业"十二五"发展规划》出台,江西省提出到2015年全省光伏产业收入达2500亿元,并把光伏发电成本控制在每千瓦时1元以内。若这一目标实现,将增大推广光伏发电的可行性。同样吸引媒体眼球的还有正在召开的多哈气候大会。不少业内专家在谈到清洁能源应对气候变化的贡献

During the rebuilding of Jiangxi power grid after ice trouble,the structure of power grid changes continuously.This kind of great change of power grid challenges the reliability of protection.In this paper,the robustness of the relay protection setting in Jiangxi power grid is discussed.Furthermore,measures are presented to improve the reliability of protection devices.

This paper presents a new single terminal method of traveling wave fault location using wavelet transform for transmission line The proposed method ean effectively extract the characteristic of traveling wave, eliminate the effects of the traveling wave dispersion on the fault location accuracy, and make the definition of arrival time and the choice of propagation velocity more reasonable A large amount of fault location results show that the new method is more accurate and reliable, and can meet the accurate fault location requirement when single terminal methods of traveling wave can be used in some position