基于启发式线性规划的大规模安全约束调度快速求解方法

提升大规模安全约束经济调度优化模型的求解性能是开展大电网跨省区电力电量全局优化平衡的前提与基础。首先分析问题的物理特性,通过并行计算求解不考虑机组爬坡约束的分时段约束松弛模型。基于对松弛解的分析获得可用于指导安全约束经济调度模型改进的有用信息,以约束剔除和约束增加的方式提出了基于启发式线性规划的大规模安全约束经济调度快速求解方法。将所提算法运用于新英格兰10机扩展系统和中国实际电网,验证了所提算法的正确性和有效性。     

Economic load dispatch with nonsmooth cost functions using evolutionary particle swarm optimization

This paper presents an evolutionary particle swarm optimization (EPSO) method for solving the nonconvex economic load dispatch (ELD) problem. In practice, the nonconvex and the discontinuous cost function should be considered when optimizing ELD problem with constraints such as valve point effects, prohibited operating zones, ramp‐rate limits, and transmission loss of the system. In view of these constraints, the ELD problem is difficult to solve by any mathematical method. In EPSO, the evolutionary programming concept (combination, tournament competition, sorting, and selection) is employed in the classical PSO method in order to find the best individual and best group position based on the survival particle. The effectiveness of the EPSO is tested on 3‐, 6‐, 15‐, and 38‐unit systems. The results obtained by EPSO are also compared with classical PSO and other results reported in the literature. It is concluded that the EPSO method can produce lower generation cost compared to the existing methods. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

采用分布式单纯形法的微电网分散式动态经济调度

对含多种分布式电源的微电网,基于分布式单纯形法,提出了一种求解微电网动态经济调度问题的分散式优化算法。通过对目标函数进行线性化,建立了微电网动态经济调度的线性规划模型。将每个分布式电源均视为独立的智能体,从而将线性规划模型中的成本向量和约束方程系数矩阵按智能体进行分块,进而采用分布式单纯形法求解。每次迭代过程中,智能体通过通信网络传递当前解对应的最优基和成本向量。所提算法不需要中央控制器的参与,智能体间具有一定的信息保密性,且通信次数与通信网络的直径成线性增长的关系。最后,以某实际微电网为测试系统,验证了线性化模型的准确性和算法的有效性。     

基于PSO-BBO混合优化算法的动态经济调度问题

动态经济调度(Dynamic Economic Dispatch,DED)问题是电力系统运行与控制领域比较经典的多变量、非线性、强约束优化问题。为解决该问题,提出了将粒子群优化算法(Particle Swarm Optimization,PSO)和基本生物地理学优化算法(Biogeography-Based Optimization,BBO)相结合的改进生物地理学优化算法,并将该改进方法应用于一天24时段10机39节点标准算例。在考虑网损与不考虑网损两种情况下分别进行仿真分析,并将仿真结果与PSO和基本BBO算法以及参考文献中提出的六种智能算法进行对比,验证了该改进算法的有效性及在寻优能力上的提高。     

Security constrained economic load dispatch using improved particle swarm optimization suitable for utility system

The objective of this paper is to evolve simple and effective methods for the economic load dispatch (ELD) problem with security constraints in thermal units, which are capable of obtaining economic scheduling for utility system. In the proposed improved particle swarm optimization (IPSO) method, a new velocity strategy equation is formulated suitable for a large scale system and the features of constriction factor approach (CFA) are also incorporated into the proposed approach. The CFA generates higher quality solutions than the conventional PSO approach. The proposed approach takes security constraints such as line flow constraints and bus voltage limits into account. In this paper, two different systems IEEE-14 bus and 66-bus Indian utility system have been considered for investigations and the results clearly show that the proposed IPSO method is very competent in solving ELD problem in comparison with other existing methods.     

Analytical solution for combined economic and emissions dispatch

Due to the environmental concerns that evolve from the emissions produced by fossil-fuelled power plants, the economic dispatch that minimises only the total fuel cost can no longer be considered single-handed. This paper proposes an analytical strategy based on mathematical modelling to solve economic, emission, and combined economic and emission dispatch problems by a single equivalent objective function. The proposed strategy has been applied to dissimilar realistic systems at different load conditions and the outcome of one such realistic system is presented here.     

随机风电接入的电力系统动态经济调度多场景协同优化

针对随机风电接入的电力系统动态经济调度问题,采用场景法应对随机风电接入带来的不确定性,并以发电总成本最小为优化目标,结合多学科协同优化算法的核心思想建立基于多场景解耦的电力系统动态经济调度协同优化模型。引入动态松弛算法求解模型的系统级优化问题,有效克服传统多学科协同优化算法的不足;采用网格计算工具并行求解由多场景构建的子学科优化问题,大幅提高求解规模和计算效率。含风电的IEEE 39节点系统仿真结果表明,所提模型是可行有效的,并且优化效果要优于基于GAMS-BARON求解器的传统场景法。     

应用粒子群优化算法求解市场环境下的电力系统动态经济调度问题

在竞争性的电力市场环境下,为了获得最大化的社会利润,提出了基于竞价机制的动态经济调度模型,该模型综合考虑了发电机组的爬坡约束、输电线路的容量约束和污染气体排放量的约束。针对该模型,提出了一种新的求解方法:粒子群优化算法(PSO)。算例的结果表明,PSO算法能够有效地得到一个高性能的优化调度结果     

不同运行调度模式下微网经济运行对比分析

为了对比分析不同运行调度模式对微网经济运行的影响,在考虑微源同时提供有功和无功功率的基础上,提出了计及制热收益的热电联产型微网系统经济运行优化模型.以一个包含风、光、储、微型燃气轮机、燃料电池以及热电负荷的具体微网为例,提出了不同运行调度模式下的经济调度策略,运用改进遗传算法优化了考虑实时电价的并网运行方式下各微源的有功和无功出力,并对比分析了微网与外网交互功率的约束以及不同运行调度模式对经济调度的影响.仿真结果表明微网可与外网自由双向交换功率的模式更具有经济优势,验证了所提模型、策略和算法的有效性.     

Artificial immune system for dynamic economic dispatch

Dynamic economic dispatch determines the optimal scheduling of online generator outputs with predicted load demands over a certain period of time taking into consideration the ramp rate limits of the generators. This paper proposes artificial immune system based on the clonal selection principle for solving dynamic economic dispatch problem. This approach implements adaptive cloning, hyper-mutation, aging operator and tournament selection. Numerical results of a ten-unit system with nonsmooth fuel cost function have been presented to validate the performance of the proposed algorithm. The results obtained from the proposed algorithm are compared with those obtained from particle swarm optimization and evolutionary programming. From numerical results, it is found that the proposed artificial immune system based approach is able to provide better solution than particle swarm optimization and evolutionary programming in terms of minimum cost and computation time.     

电力系统经济负荷分配的量子粒子群算法

本文首次将量子粒子群算法用于电力系统经济负荷分配中。该算法是以粒子群中粒子的收敛特性为基础,依据量子物理理论提出的,改变了传统粒子群算法的搜索策略,可使粒子在整个可行解空间中搜索寻求全局最优解。同时该算法的进化方程中不需要速度向量,而且进化方程的形式更简单,参数较少且容易控制。对两个算例进行仿真测试,证实该算法可有效解决经济负荷分配问题;性能对比显示,该算法求得的解优于已有的改进粒子群算法及其它优化算法所求得的解。本文为量子粒子群算法用于经济负荷分配的实用化研究奠定了必要的理论基础。     

Emission,reserve and economic load dispatch problem with non-smooth and non-convex cost functions using epsilon-multi-objective genetic algorithm variable

This paper addresses a novel method for the multi-objective economic load dispatch (ELD) problem. Power generation, spinning reserve costs and emission are considered in the objective function of the frequency ELD problem. The frequency deviation, minimum frequency limits and other practical constraints are also taken into account in this problem. It is a highly constrained multi-objective optimization problem that involves conflicting objectives with both equality and inequality constraints. In this paper, an elitist evolutionary multi-objective optimization algorithm based on the concept of ε-dominance, called ε-multi-objective genetic algorithm variable (εv-MOGA), is proposed to solve the frequency ELD problem. In this study, the performance of the proposed εv-MOGA algorithm is compared with the performance of other classic and intelligent algorithms. The proposed method is tested on 6, 10, 13 and 40 generating units, and the simulation results of four power systems demonstrate the advantages of the proposed method for reducing the cost function.     

Stochastic economic emission load dispatch through a modified particle swarm optimization algorithm

Conventional economic load dispatch problem uses deterministic models, which are however not able to reflect some real situations in practical applications since certain inaccurate and uncertain factors are normally involved in system operations. Stochastic models are more suited to be used for investigating some of the power dispatch problems. In this paper, both deterministic and stochastic models are first formulated, and then an improved particle swarm optimization (PSO) method is developed to deal with the economic load dispatch while simultaneously considering the environmental impact. Comparative studies are carried out to examine the effectiveness of the proposed approach. First, a comparison is made between the proposed PSO approach and other approaches including weighted aggregation and evolutionary optimization. Then, based on the proposed PSO, the impacts of different problem formulations including stochastic and deterministic models on power dispatch results are investigated and analyzed.     

A novel particle swarm optimization method based on quantum mechanics computation for thermal economic load dispatch problem

This paper presents an efficient strategy to solve the thermal economic load dispatch (ELD) problem by considering several aspects of ELD. ELD performs an important role in the economical operation of power system, which essentially involves nonlinearity according to the characteristics of the generators. The complexity is amplified when the generators' prohibited zones and valve‐point effect are considered, which makes ELD a nonconvex and nonsmooth problem. The strategy employs a mechanism involving a quantum mechanics‐inspired particle swarm optimization (QMPSO). The conventional PSO is modified by integrating quantum mechanical theory which redefines the particles' positions and velocities in a dynamic manner and therefore explores more search space. The QMPSO employs a multipopulation‐based scheme which ensures particle movement and avoids premature convergence at the same time. Moreover, in order to diversify the particles, a dynamic mutation operator is introduced in the proposed method. Such features deliver a fine balance between the local and global searching abilities. Simulations are carried out by considering several cases of thermal units of varying combinations of system configurations such as with and without the valve point, with and without network loss, and for one or several hours of load demand. The results are quite promising and effective compared with several benchmark methods. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Solving economic load dispatch problems in power systems using chaotic and Gaussian particle swarm optimization approaches

The objective of the Economic Dispatch Problems (EDPs) of electric power generation is to schedule the committed generating units outputs so as to meet the required load demand at minimum operating cost while satisfying all units and system equality and inequality constraints. Recently, global optimization approaches inspired by swarm intelligence and evolutionary computation approaches have proven to be a potential alternative for the optimization of difficult EDPs. Particle swarm optimization (PSO) is a population-based stochastic algorithm driven by the simulation of a social psychological metaphor instead of the survival of the fittest individual. Inspired by the swarm intelligence and probabilities theories, this work presents the use of combining of PSO, Gaussian probability distribution functions and/or chaotic sequences. In this context, this paper proposes improved PSO approaches for solving EDPs that takes into account nonlinear generator features such as ramp-rate limits and prohibited operating zones in the power system operation. The PSO and its variants are validated for two test systems consisting of 15 and 20 thermal generation units. The proposed combined method outperforms other modern metaheuristic optimization techniques reported in the recent literature in solving for the two constrained EDPs case studies.     

含抽水蓄能电站的电力系统动态环境经济调度与效益分析

针对抽水蓄能机组在调度中的作用无法合理体现和对其存在错误认知的问题,提出了对抽水蓄能机组进行全面的效益评估,即利用两部制电价合理反映抽水蓄能机组的容量效益和电量效益.在火电价格中引入环境名义补偿价格,建立了能够体现抽水蓄能电站效益的环境经济调度模型,并引入粒子浓度认知的粒子群算法对模型进行求解.通过算例证明了抽水蓄能机组在环境经济调度中能够带来经济效益,有利于提高抽水蓄能电站的利用率.     

考虑可靠性约束的含风电场电力系统动态经济调度

提出一种考虑系统可靠性约束的含风电场电力系统动态经济调度模型,在目标函数中加入了中断负荷费用.针对风速预测和负荷预测的不确定性,引入净负荷的概念,利用七分段高斯分布模拟预测误差的不确定性.在系统可靠性指标的计算过程中,考虑了系统机组的不确定性以及旋转备用.为求解模型,提出了一种改进的粒子群优化算法,引入信息分享和精英学习策略.以IEEE-RTS测试系统为算例,通过仿真分析,验证了所提模型的可行性与有效性.该模型可以在保证系统可靠性水平的基础上优化系统调度.     

基于负荷均衡加载的电力系统分布式经济调度策略

在构建以新能源为主题的新型电力系统背景下,电网面临以电动汽车为代表的电气化交通负荷剧增的巨大挑战。针对上述问题提出一种负荷均衡优化模型,将负荷均衡后的集群电动汽车依次并入电网。然后应用多智能体一致性算法,以发电机组的增量成本和集群电动汽车的增量效益作为一致性变量,设计一种集群电动汽车参与电力系统经济调度的算法,通过分布式优化方式解决经济调度问题。建立4种典型的仿真情景,分别验证集群电动汽车分步参与电力系统分布式优化调度的有效性、对不同通信拓扑和功率受约束情况的适用性以及分布式优化算法在集群电动汽车参与经济调度时“即插即用”的能力。在IEEE 39节点系统上进行算例仿真,验证了策略的有效性。     

A hybrid genetic algorithm and bacterial foraging approach for dynamic economic dispatch problem

Dynamic economic dispatch (DED) is one of the most significant non-linear complicated problems showing non-convex characteristic in power systems. This is due to the effect of valve-points in the generating units’ cost functions, the ramp-rate limits and transmission losses. Hence, proposing an effective solution method for this optimization problem is of great interest. The original bacterial foraging (BF) optimization algorithm suffers from poor convergence characteristics for larger constrained problems. To overcome this drawback, a hybrid genetic algorithm and bacterial foraging (HGABF) approach is presented in this paper to solve the dynamic economic dispatch problem considering valve-point effects, ramp-rate limits and transmission losses. The HGABF approach can be derived by integrating BF algorithm and genetic algorithm (GA), so that the BF’s drawback can be treated before employing it to solve the complex and high dimensioned search space of the DED problem. To illustrate the effectiveness of the HGABF approach, several test systems with different numbers of generating units are used. The results of HGABF approach are compared with those obtained by other published methods employing same test systems. These results show the effectiveness and the superiority of the introduced method over other published methods.     

Handling non-convex heat-power feasible region in combined heat and power economic dispatch

The combined heat and power economic dispatch (CHPED) problem enhances the conversion efficiency from fossil fuels into electricity, eventually reducing the green house gas. However, the optimization formulation for a popular bench-mark example has not properly considered the constraint of heat-power feasible operating region so far. Thus, this study proposes a novel technique to consider the non-convex heat-power feasible region in the CHPED problem more accurately. This study divides the non-convex operating region into two convex operating sub-regions by introducing two binary variables indicating the searching region. In addition, more accurate results and better demand constraints are proposed to more fairly compare the results for this bench-mark problem in the future.