Path-set based optimal planning of new urban distribution networks

This paper presents a method for optimal planning of new urban distribution networks based upon the selection of the best subset of paths providing back feed from the entire path set generated for the available cable routes. The optimal solution is the path subset providing minimum total annual cost including capital recovery, loss and undelivered energy costs while satisfying all technical constraints. The impacts of distributed generator units, if available, can be also taken into account in the optimization flow. The reliability requirements are additionally assured by introducing SAIFI and SAIDI constraints. The method allows for common trenches for cables and different sizes of feeders depending on their loads. The planner is allowed to choose the concept of back feed, through only feeders interconnecting source nodes, ring feeders or by the best combination of these two structures. During the optimization process the optimal distribution system trees are generated providing minimum loss operation. The search for the optimal network is conducted using the simulated annealing algorithm.     

基于权值D-S证据理论的车辆路径优化

最优路径规划是车载导航系统的一个重要功能,针对目前路径规划易陷于进行简单的加权求和,结果不够理想的缺陷,提出将道路属性数据进行量化,应用D-S证据理论将道路属性进行融合,所得的数据作为道路权值。并利用蚁群算法应用于该问题计算,实验结果表明,改进后的算法合理、有效。     

基于随机期望值规划的输电网规划方法

电力市场环境下输电网规划面临大量的不确定因素的影响,运用不确定规划理论建立了输电网随机期望值规划模型,采用随机数来描述新增发电机节点出力,新增节点负荷变化值,新增线路造价的不确定性因素,利用Monte-Carlo仿真和改进小生境遗传算法求解模型,修改的18和46节点系统验证了所提模型和方法有效.     

DG integrated multistage distribution system expansion planning

In this paper, a framework is presented to solve the problem of multistage distribution system expansion planning in which installation and/or reinforcement of substations, feeders and distributed generation units are taken into consideration as possible solutions for system capacity expansion. The proposed formulation considers investment, operation, and outage costs of the system. The expansion methodology is based on pseudo-dynamic procedure. A combined genetic algorithm (GA) and optimal power flow (OPF) is developed as an optimization tool to solve the problem. The performance of the proposed approach is assessed and illustrated by numerical studies on a typical distribution system.     

Practical method for generation expansion planning based on dynamic programming

This paper presents an efficient method which provides the optimal generation mix and the optimal generation construction process. The approximation method in which the dynamic programming technique and gradient method are combined is applied to determine the optimal generation mix with hydropower generation technologies. The successive approximations dynamic programming (SADP) technique, which is very suitable for high-dimensional multistage decision process problems, is used for obtaining the optimal generation construction process. The effectiveness and feasibility of the developed technique are demonstrated on a practical power system model which has five types of generation technologies including a hydropower generation technology.     

基于改进蚁群算法的输电网络扩展规划

输电网络扩展规划问题是一个复杂的组合优化问题。蚁群算法是用于解决组合优化问题的一种高效的随机化内启发式全局搜索技术。文中结合单阶段输电网络扩展规划问题的特点，应用改进的蚁群算法来解决输电网络扩展规划问题，建立了相应的数学模型，并给出求解算法。2个算例系统的计算结果表明了这种方法可有效减小搜索空间，并具有计算速度快和收敛性好等优点。     

基于云理论的输电投资项目实物期权评价研究

由于受到电力市场环境下多方面不确定性因素的影响,难以准确计算投资输电项目的现金流和内部收益率等关键决策指标,增加了电网投资项目的投资风险和决策难度.基于云理论描述了电网投资项目的现金流的模糊特性,较以往单纯依靠模糊数的方法更加符合决策者的思维判断模式,并充分体现了电网投资建设中不确定因素和模糊集隶属度的随机性.结合实物期权理论,构造了不确定环境下输电项目投资评价的新的方法框架,提出了基于云理论的输电项目实物期权投资决策模型,并以实例证明了该方法的有效性和可行性.     

基于系统动力学的配电网规划评价

电网规划评价方法大都侧重于电网的静态分析,对电网发展的趋势及动态特性并未进行分析,使得评价结果有一定的局限性.鉴于系统动力学在缺少数据的情况下仍具有较强的定量分析能力,应用系统动力学中因果反馈的原理,提出一种基于系统动力学的配电网动态分析评估体系与模型,通过选取适当的技术经济指标进行动态模拟,分析得到电网规划方案的评价结论.该模型通过对评价对象的仿真建模,可以全面、动态地考虑与评价对象相关的各种影响因素.将所建立的动态评估模型应用于上海某10kV区域配电网规划方案的评价,结果显示,各种相关的影响因素在系统动力学模型中可以得到充分的考虑,从而能有效、方便地对配电网进行动态的规划评价,使评价结果更客观和具应用价值.     

Multiobjective electric distribution system expansion planning using hybrid energy hub concept

This paper presents a novel approach for optimal electric distribution system expansion planning (OEDSEP) using a hybrid energy hub concept. The proposed method uses an energy hub model to explore the impacts of energy carrier systems on OEDSEP procedure. This algorithm decomposes the OEDSEP problem into three subproblems to achieve an optimal expansion planning of a system in which the investment and operational costs are minimized, while the reliability of the system is maximized. The algorithm was successfully tested in the present research for an urban distribution system.     

Generation expansion planning in electricity markets: A novel framework based on dynamic stochastic MPEC

This paper presents a novel framework for generation expansion planning (GEP) of restructured power systems under uncertainty in a multi-period horizon, which includes generation investment from a price maker perspective. The investment problem is modeled as a bi-level optimization problem. The first level problem includes decisions related to investment in order to maximize total profit in the planning horizon. The second level problem consists of maximizing social welfare where the power market is cleared. Rival uncertainties on offering and investment are modeled using sets of scenarios. The bi-level optimization problem is then converted to a dynamic stochastic MPEC and represented as a mixed integer linear program (MILP) after linearization. The proposed framework is examined on a typical six-bus power network, MAZANDARAN regional electric company (MREC) transmission network as an area of IRAN interconnected power system and IEEE RTS 24-bus network. Simulation results confirm that the proposed framework can be a useful tool for analyzing the behavior of investments in electricity markets.     

基于凸优化理论的多传感器故障诊断技术

针对DS证据理论基本概率赋值函数难以获取、证据问要求相互独立等缺点,提出了利用凸优化理论来建立满足需要的多传感器故障诊断模型。本文首先分析了传感器故障诊断报告的形式,构造了多传感器故障融合的代价函数。通过分解代价函数,将多传感器故障诊断问题转换为凸优化问题。同时利用对数罚函数内点算法求解凸优化模型,该算法结构简单,计算量小,易于实现。理论分析和仿真结果表明,基于凸优化模型的多传感器故障诊断方法较之传统的DS证据方法具有更好的识别能力、更强的鲁棒性和更广的适用范围。     

基于伪动态的混沌人工鱼群算法在多阶段输电网络规划中的应用

与传统输电网络规划不同,多阶段输电网络规划需要考虑时段因素,在何阶段搭建何种路线使全局规划方案最优。多阶段规划的难点是阶段之间的过渡,后面阶段的决策要根据前面阶段的决策来定,对于大规模输电网规划经典的动态规划方法无法解决。利用伪动态规划的思想处理多阶段问题,这样减少了算法的迭代次数和运算时间。将混沌优化算法和人工鱼群算法相结合,摆脱了混沌搜索的盲目性和人工鱼搜索的局限性,使该混合算法效率高、收敛速度快。对巴西南部46节点系统的计算结果表明,该混合算法具有可行性和高效性。     

Loop frame of reference based three-phase power flow for unbalanced radial distribution systems

This paper introduces a novel three-phase power flow approach for unbalanced radial distribution systems. The proposed approach is developed based on the loop frame of reference, rather than the traditional bus frame of reference. On the basis of the loop frame of reference, a simple direct iterative method in impedance form is applied. Basic graph theory and injection current technique are also applied in the proposed approach. The clear theoretical foundation and the simple topology of the radial distribution network make the proposed method efficient and reliable. To demonstrate the better convergence performance and the efficiency of the proposed approach, four three-phase IEEE test feeders are used for comparisons. The test results show that the proposed method has robust convergence characteristics and high performance, especially for large-scale radial distribution systems.     

基于米氏散射理论的粒度测试算法研究

在光散射法测量微粒体系粒度分布技术中,反演算法的选择及其正确使用是很关键的。介绍了基于米氏散射理论的粒度测试,对其求解方法进行了详细分析,力图通过算法的改进提高激光粒度仪的粒度测试精度。综合采用了直接法NNPT和迭代法LMS的优点,在稳定性和准确性方面得到了一定程度的改进,并对算法进行了验证。     

基于小波变换和贝叶斯理论的图像分割算法

基于非下采样小波变换和贝叶斯分类理论的图像分割算法,在处理可见光图像时,容易受到噪声的干扰,而且,原算法在计算最大局部最小点时易产生偏差,从而影响分割效果。因此,本文首先使用滤波器滤除噪声,然后对原来的最大局部最小点的计算方法进行了等价变换,并调整了分割阈值以纠正由于对图像进行小波变换造成的灰度偏移,最后利用数学形态学运算对分割后的图像进行处理以消除孤立点,仿真结果表明改进算法分割效果较好。     

基于集对分析的中压配电网网架优化规划

分析了配电网规划中存在的各种不确定性因素,引入集对分析概念,指出该理论在解决配电网规划的各种不确定性因素时所具有的优势.论述了利用模糊集对分析理论建立中压配电网规划模型的原理和步骤,并通过Prufer数编码、伪随机初始化方式、适应度函数的选择、传统遗传操作算子的改进以及约束条件的处理等方面,运用遗传算法对模型进行求解.通过两组算例对得到的基于模糊集对分析的中压配电网规划模型的实现算法进行验证,计算结果表明本模型对中压配电网网架的规划非常有效.     

基于多目标模型的城市中压配电网络规划

实际的城市中压配电网络规划是一个需要同时考虑经济性和可靠性的多目标组合优化问题。现有的研究虽有所提及,但仍未很好解决此类问题。首先设计了计及配电网各设备的年投资与运行总费用的经济性指标和将可靠性效益转化为用户缺电成本的可靠性指标,并采用模糊技术对这2个指标进行模糊化以使其具有同等地位,在此基础上建立了城市中压配电网络规划的多目标模型。设计了新型多目标遗传算法,在选择运算中考虑了多目标优化问题的特点,即提出混合使用了并列选择法、保留最佳个体和共享函数法的选择算子,变异运算采用了TS变异操作。通过算例分析验证了所建模型和所提方法的可行性。     

Optimal planning of rural medium voltage distribution networks

A model is suggested for selection of main initial parameters and timing of the reconstructions of rural distribution networks in long-term planning to meet the increasing load demands with minimum total present worth cost. The model incorporates capital and exploitation costs as well as the costs due to undelivered energy and load curtailments. The optimal investment policy is determined using a constrained dynamic programming technique which indicates the best choice among possible options while taking into account all relevant technical criteria and common-sense rules.     

基于正态分布理论的电能质量指标95概率大值算法研究

电能质量指标95概率大值是电能质量领域基础数据之一,是执行电能质量统计、分析和评估的重要依据。目前多采用排序算法来计算电能质量指标95概率大值,但实践中发现该算法在大数据量下性能迅速下降,无法满足实际应用需要。基于正态分布及标准化变换理论提出一种95概率大值新算法,对算法原理、流程进行了详细说明,并针对新老算法进行比对性试验。试验证明新算法在准确度上满足要求,且具有更高的计算效率,因此具有良好的应用前景。     

基于D-S证据理论的配电网单相故障选线方法研究

为充分利用单相接地故障的互补信息提高选线保护的可靠性,提出一种中性点非有效接地电网信息融合选线方法。该方法采用D-S证据理论,针对故障选线问题的具体特点,合理构造了选线识别框架和信度分配函数,将故障选线问题转化为证据理论模型,给出证据组合的选线判定原则,制定了基于信息融合的综合选线策略。应用该方法在模拟系统上进行实验,验证了方法的有效性。结果表明采用融合选线策略极大地提高了故障选线的可靠性。