基于故障风险指标排序的安全约束最优潮流

安全约束最优潮流(SCOPF)是一种常用的电力系统运行调度方法,但由于需要考虑大量的预想事故,问题的求解十分困难。如何加快SCOPF的求解速度是现阶段研究的热点问题。在传统的基于故障严重度排序的安全约束最优潮流基础上进行改进,采用改进过载风险指标代替传统的严重度指标,并考虑电力网络实时的天气状况,提出了一种新型的基于故障过载风险指标排序的安全约束最优潮流算法。算例分析表明,该算法所采用的故障集更小,具有迭代速度快、安全性高和经济性好的特点,可为调度员的运行决策提供重要参考。     

Optimal Automatic Generation Control of Asynchronous Power Systems Using Output Feedback Control Strategy with Dynamic Participation of Wind Turbines

Abstract—This article presents the design of optimal output feedback automatic generation control regulators for an interconnected power system with dynamic participation of doubly fed induction generator based wind turbines. The power systems consist of plants with hydro-thermal turbines and are interconnected via parallel AC/DC links. Efforts have been made to propose optimal automatic generation control regulators based on feedback of output state variables, which are easily accessible and available for the measurement. The designed optimal output feedback automatic generation control regulators are implemented, and the system dynamic responses for various system states are obtained considering 1% load perturbation in one of the areas. The dynamic performance is compared with that obtained with optimal automatic generation control regulators designed using full state vector feedback. The pattern of closed-loop eigenvalues is also determined to test the system stability.     

Optimal Placement of Phasor Measurement Units with Linear and Non-linear Models

Abstract—This article presents a non-linear programming-based model for the optimal placement of phasor measurement units. The optimal phasor measurement units placement is formulated to minimize the number of phasor measurement units required for full system observability and to maximize the measurement redundancy at all buses in a power system. A sequential quadratic programming algorithm is used for the solution of the proposed model. The existence of power flow and injection measurements, the limited phasor measurement units channel capacity, the lack of communication facilities in substations, and the single phasor measurement units loss are also incorporated into the initial proposed formulation. The non-linear programming model is applied to IEEE 14- and 118-bus test systems in MATLAB. The accuracy and the effectiveness of the proposed method is verified by comparing the simulation results to those obtained by a binary integer programming model also implemented in MATLAB. The comparative study shows that the proposed non-linear programming model yields the same number of phasor measurement units as the binary integer programming model. A remarkable advantage of the non-linear programming against binary integer linear programming is its capability to give more than one optimal solution, each one having the same minimum number of phasor measurement units (same minimum objective value), but at different locations.     

Hybrid Fuzzy-particle Swarm Optimization-simplex (F-PSO-S) Algorithm for Optimum Design of PM Drive Couplings

This paper aimed at exploring the use of the proposed hybrid Fuzzy-Particle Swarm Optimization-Simplex (F-PSO-S) algorithm to optimize the structural design of PM couplings subject to several key design constraints. The new proposed hybrid optimization algorithm is constructed based on combining three well-known techniques: fuzzy logic (FL), particle swarm optimization (PSO), and simplex method (SM). FL is used to aggregate different scaling and/or conflicting objectives in one objective function using fuzzy combination operators. On the other hand, the PSO has obvious capabilities in global search whereas the SM has exceptional advantages in local search. As a hybrid algorithm, the F-PSO-S has the outstanding feature of combining the ability of global searching and local canvassing for different scales and/or conflicting objective functions. The proposed algorithm has been applied to permanent magnet (PM) drive couplings. A standard coupling design is used as a good initial point for the conventional SM and to define the performance constraints for the proposed optimization technique. New coupling designs are developed and optimized to show the superior capabilities of the F-PSO-S algorithm as a global optimization technique. The sensitivity analysis is also performed to identify the effects of different design parameters on the coupling performance.     

基于多状态建模的独立型微网优化配置

针对风速、光照强度和负荷不确定性对独立型微网优化配置的影响,应用三者的概率密度函数对每个月份构造典型日,利用多状态系统理论对典型日各个时刻风光出力和负荷进行了多状态建模。以经济性和环保性为目标,建立了基于多状态建模的独立型微网多目标优化配置模型,并采用改进的非劣排序遗传算法(NAGA-Ⅱ)对模型进行了求解。最后,针对某一算例分别使用所提出的优化配置方法和已有的基于确定历史场景的优化配置方法进行了仿真计算,通过对仿真结果在若干随机场景下的比较分析,验证了所提优化配置模型和方法的合理性和有效性。     

综合考虑投资成本和经济收益的快速切回机组布点方案

随着大型火电机组快速切回(FCB)技术的成熟,将FCB机组作为大停电后黑启动电源的设想成为可能。规划FCB机组的布点位置,应兼顾工程实际。文中首先采用图论方法推导了最优布点方案的性质,证明已知活跃顶点个数的最优布点方案具有继承性。继而提出采用递推法对FCB机组布点方案进行寻优。然后,建立了FCB机组布点方案的经济效益指标,基于递推法计算结果,依据该指标筛选出同时满足安全性和经济性要求的FCB机组最优布点方案。算例分析结果表明,递推法较常规方法计算效率高、鲁棒性强。并且,结合经济性指标,得到的结果方案可作为实际系统黑启动电源规划的决策依据。     

基于电压控制分区的发电机无功备用优化方法

发电机无功备用对电力系统电压稳定和电压控制具有重要意义。提出了基于电压控制分区的区域发电机无功备用定义,该定义综合衡量了区域发电机无功备用对静态电压稳定和准稳态电压控制的价值以及无功备用的可供给性。分析了控制变量的特性和选取方式,建立了用于优化区域无功备用和区域电压水平的二次规划模型,提出了逐次分区优化求解算法。通过3节点系统算例验证了无功备用定义和控制变量选取方式的合理性。通过IEEE 118系统算例验证了优化方法的正确性和可行性,优化方案显著提高了区域无功备用量和电压稳定裕度,改善了电压水平。区域无功备用优化方法将高维的无功备用优化原问题简化为少量的低维区域优化子问题,具有较高的容错性和计算效率,可用于较大规模系统的发电机无功备用评估和优化。     

计及相关性的电—气互联系统概率最优潮流

为了缓解环境污染,"减煤增气"已成为能源结构调整的大趋势,"能源互联网"的提出加强了天然气网络与电力系统的紧密耦合。传统以电力系统为对象的最优潮流忽略了天然气网络的运行约束对电力系统造成的影响,可能导致优化结果过于乐观。因此提出了一种电—气互联系统的联合最优潮流,以互联系统的总运行成本为优化目标,考虑电力网与天然气网的运行约束。并且针对新能源接入背景下的不确定性,考虑输入变量之间的相关性,采用基于Nataf变换的点估计法进行概率最优潮流计算。对修改的IEEE 39节点系统与比利时20节点天然气网络进行算例分析,验证了所提模型的可行性以及有效性,并在此基础上分析了不同的波动水平及相关性对系统运行特性的影响。     

考虑用户定量需求的优质电力园区DVR优化配置

优质电力园区是针对区域性高品质供电问题的一种有效解决方案,其中定制电力设备配置方案的确定是园区规划建设的重要内容。针对园区中动态电压恢复器(dynamic voltage restorer,DVR)的配置问题,提出一种考虑用户短时电压质量定量需求的DVR优化配置策略。基于过程抗扰时间和物理参数变化曲线,将用户对过程运行状态需求映射为短时电压质量需求,实现用户需求量化;以DVR投资最少为目标,满足用户需求为约束,建立DVR优化配置模型,用Tabu搜索算法求解,得到优化配置方案。对典型园区的仿真结果表明,该方法所得配置方案经济、可行,能在满足用户短时电压质量定量需求的同时,保证DVR投资最少。     

现代有轨电车正线道岔控制系统方案研究

针对现代有轨电车信号控制系统,分析了系统需要解决的关键问题。重点对信号系统中涉及安全的正线道岔控制子系统,分析了系统的功能、组成和结构,对系统中转辙机控制、车地通信和列车定位等关键集成技术进行了分析对比,提出了一种兼顾效率与安全考虑的进路控制方法和一套基于完全国产化技术的系统方案。