电力系统动态环境经济调度问题的建模与求解

为了在电力系统优化调度中同时兼顾整个时段的经济和环境效益,该文建立了考虑阀点效应和系统网损的电力系统动态环境经济调度模型,提出了一种改进的多目标教与学优化算法对模型进行求解。算法引入了反向学习策略、外部最优解集策略、基于个体稀疏度的教师选取策略、模糊满意度和动态班级策略,通过动态启发式随机约束处理与罚函数相结合的方法对违背约束的个体进行修正与惩罚。最后,用10机算例对文中提出的模型和算法进行了仿真测试,并与其他算法进行了对比。仿真结果表明文中算法的有效性和优越性。     

求解电力系统多目标环境经济调度的帕累托最优MFO算法

本文提出了一种利用MFO算法解决电力系统环境经济调度的新方法,该算法利用飞蛾扑火原理对设定目标进行螺旋式搜索,并在目标位置进行重复检索。MFO算法对于大规模非线性规划问题具有较强的适应性和有效性。在求解环境经济调度问题中,结合实际发电系统运行过程中应满足的功率平衡约束和容量约束等,以总燃料成本和污染排放最低为目标建立多目标规划数学模型。运用帕累托最优前沿求取帕累托非劣性最优解,得到帕累托最优配置方案,在可行域中搜索出全局最优解。在MATLAB仿真平台对含40台发电机组系统进行仿真计算,结果表明本文提出算法在求解电力系统环境经济调度中具有较高的收敛性和较强的适应性。     

采用基于分解的多目标进化算法的电力环境经济调度

为了准确、快速地求解电力系统环境经济调度(environmental economic dispatching,EED)问题,将基于分解的多目标进化算法(multi-objective evolutionary algorithm based on decomposition,MOEA/D)应用于电力调度领域,提出了基于MOEA/D的多目标环境经济调度算法。该算法首先采用Tchebycheff法将整个EED Pareto最优前沿的逼近问题分解为一定数量的单目标优化子问题,然后利用差分进化同时求解这些子问题,并在算法中加入约束处理及归一化操作,以获得最优的带约束EED问题的调度方案。最后,应用模糊集理论为决策者提供最优折中解。对IEEE 30节点测试系统进行仿真计算,并与其它智能优化算法的调度方案对比。结果表明,该算法有效可行,且具有很好的收敛速度和求解精度。     

采用多目标纵横交叉算法的电力系统动态环境经济调度

针对带非线性约束的电力系统动态环境经济调度问题,提出一种多目标纵横交叉算法。对动态调度中燃料费用和污染排放两个相互约束、冲突的目标同时进行优化。求解过程中,结合非约束支配策略,提出一种双交叉机制,增强粒子穿越非可行区域的能力,使得生成的帕累托最优解落在可行区域内。通过边缘探索,增强算法的全局搜索能力。同时,采用外部存档集合储存非劣解,并通过拥挤度对比,保持非劣解的多样性。最后,采用模糊决策理论获得最优折中解。对10机电力系统的仿真结果验证了所提方法的有效性与优越性。     

水火电力系统多目标环境经济调度模型及其求解算法研究

通过综合考虑发电费用最小及污染气体排放量最小这两个调度目标建立了水火电力系统多目标环境经济调度模型,并提出一种混合多目标差分进化算法对模型进行求解。该算法针对多目标优化问题的特点对差分进化算法的算子进行了修正,并基于混沌序列提出一种参数自适应调整策略以克服算法参数率定的难题。设计了一种二次变异算子来防止算法陷入局部最优。针对不同类型约束特性提出一种约束处理方法。实例计算结果及对比分析验证了所提方法的可行性和有效性,为实现水火电力系统实现经济与减排双目标均衡优化提供了一条崭新途径。     

基于飞蛾扑火算法的电力系统负荷经济调度研究

电力系统负荷经济调度是电力系统经济运行中的关键一环,在综合考虑诸多电力系统实际运行约束的基础上,建立一个相对完善的负荷经济调度模型。为提高优化解的精度和准确性,引入飞蛾扑火算法进行模型求解,并提出采用平衡机组法与传统罚函数法相结合的方式来处理模型中的功率平衡约束。采用IEEE 6机组、15机组和40机组系统进行仿真测试。仿真结果表明,所提方法可很好地解决电力系统负荷经济调度问题,并具有良好的鲁棒性,经济效益显著。     

水火电力系统多目标环境经济调度模型及其求解算法研究

通过综合考虑发电费用最小及污染气体排放量最小这两个调度目标建立了水火电力系统多目标环境经济调度模型,并提出一种混合多目标差分进化算法对模型进行求解.该算法针对多目标优化问题的特点对差分进化算法的算子进行了修正,并基于混沌序列提出一种参数自适应调整策略以克服算法参数率定的难题.设计了一种二次变异算子来防止算法陷入局部最优.针对不同类型约束特性提出一种约束处理方法.实例计算结果及对比分析验证了所提方法的可行性和有效性,为实现水火电力系统实现经济与减排双目标均衡优化提供了一条崭新途径.     

基于近端策略优化算法的新能源电力系统安全约束经济调度方法

针对高比例新能源接入导致电力系统安全约束经济调度难以高效求解的问题,该文提出了一种基于近端策略优化算法的安全约束经济调度方法。首先,建立了新能源电力系统安全约束经济调度模型。在深度强化学习框架下,定义了该模型的马尔科夫奖励过程。设计了近端策略优化算法的奖励函数机制,引导智能体高效生成满足交流潮流以及N-1安全约束的调度计划。然后,设计了调度模型与近端策略优化算法的融合机制,建立了调度训练样本的生成与提取方法以及价值网络和策略网络的训练机制。最后,采用IEEE 30节点和IEEE 118节点2个标准测试系统,验证了本文提出方法的有效性和适应性。     

基于改进多目标引力搜索算法的电力系统环境经济调度

建立了综合考虑系统运行成本和污染物排放成本的电力系统环境经济调度模型,并提出了一种改进多目标引力搜索算法(IGSA)对该模型进行求解。该算法将NSGA-II中的非劣解排序和拥挤距离的思想引入基本引力搜索算法用于处理个体偏序关系。其次针对基本引力搜索算法收敛速度慢的问题,在更新个体位置过程中受粒子群优化算法的启发对引力搜索算法的位置更新公式进行了改进;同时为了引导群体向Pareto最优解集区域靠近并保证算法解集均匀分布,采用精英保留策略;最后采用模糊集理论产生最佳折中解,为决策人员提供调度方案。算例分析验证了所提算法的可行性和有效性,为实现电力系统经济性与环保性的均衡优化提供了一条新的方法。     

基于局部随机搜索粒子群优化算法的电站短期发电优化调度

为提高粒子群优化(PSO)算法搜索精度、加快后期收敛速度,提出一种新的PSO算法,即局部随机搜索PSO算法。该算法用于求解电力系统的短期发电优化调度问题时,不仅要求满足电站实际运行中的系统负荷平衡约束,而且要考虑机组爬坡约束、出力限制区约束等非线性约束。给出了局部随机搜索PSO算法的步骤及短期发电优化调度问题求解方法。通过应用所提出的算法和其他文献提出的PSO算法、改进快速进化规划(IFEP)算法对15机系统的优化调度计算相比,证明所提出的算法最优解的发电费用最低,分别减少了3.8%和1%。     

Low-carbon emission/economic power dispatch using the multi-objective bacterial colony chemotaxis optimization algorithm considering carbon capture power plant

To study the constrained emission/economic dispatch problem involving competing objectives in electric power systems with carbon capture system (CCS) technology, this paper proposes a multi-objective optimization approach based on bacterial colony chemotaxis (MOBCC) algorithm. In this algorithm, a Lamarckian constraint handling method based approach is improved to update the bacterial colony and the external archive. Finally, the optimization tests of the proposed algorithm are carried out in the IEEE 30-bus test system. Results demonstrate this approach has the advantage of dealing with highly non-linear and multi-objective functions of carbon capture thermal generator’s emission/economic dispatch problem.     

A security constrained environmental/economic power dispatch technique using F-MSG algorithm for a power system area including limited energy supply thermal units

A security constrained non-convex environmental/economic power dispatch problem for a lossy electric power system area including limited energy supply thermal units is formulated. An iterative solution method based on modified subgradient algorithm operating on feasible values (F-MSG) and a common pseudo scaling factor for limited energy supply thermal units are used to solve it. In the proposed solution method, the F-MSG algorithm is used to solve the dispatch problem of each subinterval, while the common pseudo scaling factor is employed to adjust the amount of fuel spent by the limited energy supply thermal units during the considered operation period. We assume that limited energy supply thermal units are fueled under take-or-pay (T-O-P) agreement.The proposed dispatch technique is demonstrated on IEEE 30-bus power system with six thermal generating units having non-convex cost rate functions. Two of the generating units are selected as gas-fired limited energy supply thermal units. Pareto optimal solutions for the power system, where the constraint on the amount of fuel consumed by the limited energy supply thermal units is not considered, are calculated first. Later on, the same Pareto optimal solutions for the power system, where the fuel constraint is considered, are recalculated, and the obtained savings in the sum of optimal total fuel cost and total emission cost are presented. The dispatch problem of the first subinterval of the test system was solved previously by means of differential evolution (DE), and a hybrid method based on combination of DE and biogeography based optimization (BBO) for the best cost and the best emission cases in the literature. The results produced by these methods are compared with those of produced by the proposed method in terms of their total cost rate, emission rate and solution time values. It is demonstrated that the proposed method outperforms against the evolutionary methods mentioned in the above in terms of solution time values especially when the exact model of the test system is considered.     

Differential evolution algorithm for emission constrained economic power dispatch problem

In this paper, a differential evolution (DE) algorithm is developed to solve emission constrained economic power dispatch (ECEPD) problem. Traditionally electric power systems are operated in such a way that the total fuel cost is minimized regardless of emissions produced. With increased requirements for environmental protection, alternative strategies are required. The proposed algorithm attempts to reduce the production of atmospheric emissions such as sulfur oxides and nitrogen oxides, caused by the operation of fossil-fueled thermal generation. Such reduction is achieved by including emissions as a constraint in the objective of the overall dispatching problem. A simple constraint approach to handle the system constraints is proposed. The performance of the proposed algorithm is tested on standard IEEE 30-bus system and is compared with conventional methods. The results obtained demonstrate the effectiveness of the proposed algorithm for solving the emission constrained economic power dispatch problem.     

基于粒子群算法的电力系统经济负荷分配研究

电力系统经济负荷分配,是指在满足电力系统或发电机组运行约束条件的基础上,在各台机组间合理地分配负荷以达到最小化发电成本的目的,是经济调度中非常重要的问题。粒子群算法是一种源于对鸟群捕食的行为研究的进化计算技术,具有全局优化能力强、收敛性好和编程实现简单等优点。将粒子群算法应用于电力系统经济负荷分配问题的研究中,通过对实际算例进行仿真测试,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传统优化算法所求得的解。     

An Improved Particle Swarm Optimization for the Combined Heat and Power Dynamic Economic Dispatch Problem

—This study presents a novel improved particle swarm optimization algorithm to solve the combined heat and power dynamic economic dispatch problem. This problem is formulated as a challenging non-convex and non-linear optimization problem considering practical characteristics, such as valve-point effects, transmission losses, ramp-rate limits, mutual dependency of power and heat, spinning reserve requirements, and transmission security constraints. The proposed method combines classical particle swarm optimization with a chaotic mechanism, time-variant acceleration coefficients, and a self-adaptive mutation scheme to prevent premature convergence and improve solution quality. Moreover, multiple efficient constraint handling strategies are employed to deal with complex constraints. The effectiveness of the proposed improved particle swarm optimization for solving the combined heat and power dynamic economic dispatch problem is validated on three different test systems, and the results are compared with those of other variants of particle swarm optimization as well as other methods reported in the literature. The numerical results demonstrate the superiority of improved particle swarm optimization in solving the combined heat and power dynamic economic dispatch problem while strictly satisfying all the constraints.     

Environmental/economic power dispatch using a fuzzified multi-objective particle swarm optimization algorithm

The environmental issues that arise from the pollutant emissions produced by fossil-fueled electric power plants have become a matter of concern more recently. The conventional economic power dispatch cannot meet the environmental protection requirements, since it only considers minimizing the total fuel cost. The multi-objective generation dispatch in electric power systems treats economic and emission impact as competing objectives, which requires some reasonable tradeoff among objectives to reach an optimal solution. In this paper, a fuzzified multi-objective particle swarm optimization (FMOPSO) algorithm is proposed and implemented to dispatch the electric power considering both economic and environmental issues. The effectiveness of the proposed approach is demonstrated by comparing its performance with other approaches including weighted aggregation (WA) and evolutionary multi-objective optimization algorithms. All the simulations are conducted based on a typical test power system.     

Dynamic optical economic dispatch under system availability constraints

In this paper we have developed a dynamic optimal economic dispatch policy based on a stochastic availability model of large-scale power systems and a piece-wise constant incremental fuel cost model. Using these models the optimal economic dispatch under given system availability constraint is formulated as a dynamic nonlinear optimization problem. The random variations of demands, available generation capacities and available tie line capacities are considered as constraints in the problem. In order to solve the optimization problem an efficient algorithm based on the rule of merit-order loading has been developed. The algorithm allows large dimensionality of the system and randomness of the system parameters. The algorithm can also be easily implemented on a dispatch computer. In order to illustrate the effect of the proposed method on system generation economy and availability, an example is presented giving detailed numerical results which are very encouraging. As far as the authors know, such an economic dispatch problem which maintains the system availability index at the highest possible level (under the given system environment) has never been considered in the literature before.     

电力系统动态经济调度优化问题的膜计算方法

将膜计算方法用于求解电力系统动态经济调度优化问题。首先利用二次罚函数将多约束经济调度问题转化为无约束优化问题,对于膜计算的3个基本要素——膜内对象、膜结构和进化规则,该方法以各发电机组24时段的出力值作为膜内对象;采用具有嵌套结构的类细胞膜型膜结构,包含并行基本膜和拟高尔基体膜;在基本膜内执行交叉规则、变异规则、修正规则和保留规则,拟高尔基体被激活后执行移位规则、提取规则和目标导向规则。通过膜内对象不断进化择优,从而实现对动态经济调度问题的求解。基于IEEE 39和IEEE 118节点测试系统的算例,表明该文所提方法能够有效求解电力系统动态经济调度优化问题,与遗传算法和粒子群算法相比,该方法的计算结果和稳定性均更优,具有很好的应用前景。     

基于通用分布的含风电电力系统随机动态经济调度

随着风电大规模并网,其不确定性给电力系统经济调度带来了新的挑战。文中利用通用分布模型拟合不同风电功率预测水平下的实际风电功率分布,并以此建立了考虑风电低估、高估成本的日前动态经济调度的随机优化模型。通过对目标函数和约束条件的转化与分析,将随机优化模型转化为一个非线性凸优化问题。结合二次规划算法和内点法,提出了一种两阶段优化算法用以求解对应的经济调度问题。最后,在含风电场的IEEE 30节点系统上,验证了所提基于通用分布的随机动态经济调度方法的有效性。     

计及风电时间相关性的鲁棒机组组合

鲁棒优化是解决大规模新能源接入后电力系统调度的重要手段。相比于基于场景的随机规划、带有风险约束的机组组合等,鲁棒机组组合的结果往往偏于保守。鲁棒优化的保守性直接受到不确定集合的影响。研究了风电预测误差时间相关特点,提出了基于自相关性的时间相关性约束。并利用不确定集合的离散性特点,将该约束近似简化为可以用于实际鲁棒优化问题的线性约束。在列与限制生成(CCG)算法的基础上,改进了Bender’s分解后子问题的求解算法,提出了一种适合离散型不确定集合的鲁棒优化求解方法。最后,以真实风电数据进行了大量的仿真实验。结果表明,提出的算法能够在不影响机组组合可靠性的前提下,降低鲁棒优化保守性。