Multi-objective reservoir operation using particle swarm optimization with adaptive random inertia weights

Based on conventional particle swarm optimization(PSO),this paper presents an efficient and reliable heuristic approach using PSO with an adaptive random inertia weight(ARIW)strategy,referred to as the ARIW-PSO algorithm,to build a multi-objective optimization model for reservoir operation.Using the triangular probability density function,the inertia weight is randomly generated,and the probability density function is automatically adjusted to make the inertia weight generally greater in the initial stage of evolution,which is suitable for global searches.In the evolution process,the inertia weight gradually decreases,which is beneficial to local searches.The performance of the ARIWPSO algorithm was investigated with some classical test functions,and the results were compared with those of the genetic algorithm(GA),the conventional PSO,and other improved PSO methods.Then,the ARIW-PSO algorithm was applied to multi-objective optimal dispatch of the Panjiakou Reservoir and multi-objective flood control operation of a reservoir group on the Luanhe River in China,including the Panjiakou Reservoir,Daheiting Reservoir,and Taolinkou Reservoir.The validity of the multi-objective optimization model for multi-reservoir systems based on the ARIW-PSO algorithm was verified.

Improved particle swarm optimization algorithm for multi-reservoir system operation

In this paper, a hybrid improved particle swarm optimization （IPSO） algorithm is proposed for the optimization of hydroelectric power scheduling in multi-reservoir systems. The conventional particle swarm optimization （PSO） algorithm is improved in two ways： （1） The linearly decreasing inertia weight coefficient （LDIWC） is replaced by a self-adaptive exponential inertia weight coefficient （SEIWC）, which could make the PSO algorithm more balanceable and more effective in both global and local searches. （2） The crossover and mutation idea inspired by the genetic algorithm （GA） is imported into the particle updating method to enhance the diversity of populations. The potential ability of IPSO in nonlinear numerical function optimization was first tested with three classical benchmark functions. Then, a long-term multi-reservoir system operation model based on IPSO was designed and a case study was carried out in the Minjiang Basin in China, where there is a power system consisting of 26 hydroelectric power plants. The scheduling results of the IPSO algorithm were found to outperform PSO and to be comparable with the results of the dynamic programming successive approximation （DPSA） algorithm.

A New Class of Hybrid Particle Swarm Optimization Algorithm

A new class of hybrid particle swarm optimization （PSO） algorithm is developed for solving the premature convergence caused by some particles in standard PSO fall into stagnation. In this algorithm, the linearly decreasing inertia weight technique （LDIW） and the mutative scale chaos optimization algorithm （MSCOA） are combined with standard PSO, which are used to balance the global and local exploration abilities and enhance the local searching abilities, respectively. In order to evaluate the performance of the new method, three benchmark functions are used. The simulation results confirm the proposed algorithm can greatly enhance the searching ability and effectively improve the premature convergence.

Optimal Power Flow Solution Using Particle Swarm Optimization Technique with Global-Local Best Parameters

This paper proposes an efficient method for optimal power flow solution （OPF） using particle swarm optimization （PSO） technique. The objective of the proposed method is to find the steady state operation point in a power system which minimizes the fuel cost, while maintaining an acceptable system performance in terms of limits on generator power, line flow limits and voltage limits. In order to improvise the performance of the conventional PSO （cPSO）, the fine tuning parameters- the inertia weight and acceleration coefficients are formulated in terms of global-local best values of the objective function. These global-local best inertia weight （GLBestlW） and global-local best acceleration coefficient （GLBestAC） are incorporated into PSO in order to compute the optimal power flow solution. The proposed method has been tested on the standard IEEE 30 bus test system to prove its efficacy. The results are compared with those obtained through cPSO. It is observed that the proposed algorithm is computationally faster, in terms of the number of load flows executed and provides better results than the conventional heuristic techniques.

Enhancement in Channel Equalization Using Particle Swarm Optimization Techniques

This work proposes an improved inertia weight update method and position update method in Particle Swarm Optimization (PSO) to enhance the convergence and mean square error of channel equalizer. The search abilities of PSO are managed by the key parameter Inertia Weight (IW). A higher value leads to global search whereas a smaller value shifts the search to local which makes convergence faster. Different approaches are reported in literature to improve PSO by modifying inertia weight. This work investigates the performance of the existing PSO variants related to time varying inertia weight methods and proposes new strategies to improve the convergence and mean square error of channel equalizer. Also the position update method in PSO is modified to achieve better convergence in channel equalization. The simulation presents the enhanced performance of the proposed techniques in transversal and decision feedback models. The simulation results also analyze the superiority in linear and nonlinear channel conditions.

Algorithms for the Optimization of Well Placements—A Comparative Study

The Artificial Bee Colony (ABC) is one of the numerous stochastic algorithms for optimization that has been written for solving constrained and unconstrained optimization problems. This novel optimization algorithm is very efficient and as promising as it is;it can be favourably compared to other optimization algorithms and in some cases, it has been proven to be better than some known algorithms (like Particle Swarm Optimization (PSO)), especially when used in Well placement optimization problems that can be encountered in the Petroleum industry. In this paper, the ABC algorithm has been modified to improve its speed and convergence in finding the optimum solution to a well placement optimization problem. The effects of variations of the control parameters for both algorithms were studied, as well as the algorithms’ performances in the cases studied. The modified ABC (MABC) algorithm gave better results than the Artificial Bee Colony algorithm. It was noticed that the performance of the ABC algorithm increased with increase in the number of its optimization agents for both algorithms studied. The modified ABC algorithm overcame the challenge posed by the use of uniformly generated random numbers with very rough NPV surface. This new modified ABC algorithm proposed in this work will be a great tool in optimization for the Petroleum industry as it involves Well placements for optimum oil production.

多场景下基于AHP-EWM的人体健康状态评估模型研究

为解决人体健康评估方法个性化监测不足的问题以及在满足不同场景下健康状态精细化评估的需求,需要一种基于多场景的人体健康状态评估方法来实现长期自动化监测。提出一种基于层次分析法(AHP)和熵权法(EWM)组合的多场景人体健康状态评估模型。首先采集人体在运动、休息、工作/学习和娱乐等4种不同场景下的健康监测指标数据,构建相应的评估指标体系。然后分别根据评估指标计算出AHP和EWM权重,再采用量子粒子群优化(QPSO)算法对AHP和EWM中的主客观权重进行分配,以确保评价指标占比的客观性。最后通过模糊综合评价法对人体健康状态进行评估和量化,并利用实际监测数据对方法的可靠性和稳定性进行验证。实验结果表明,在4种场景下所提方法的综合得分分别为63.78、59.83、58.71和59.21,表明在不同场景下该模型都具有较好的准确性和稳定性。根据评估结果,对测试者的身体状态评价结果进行分析,并给出一些健康建议。所提模型可全面了解人体在不同场景下的健康状况,并为人们提供科学的健康指导,从而为健康管理和疾病预防提供科学依据。

基于改进粒子群算法优化的染色木材颜色检测算法研究

为提高染色木材颜色的检测精度和速度,对樟子松木材单板进行染色,选取染色单板的光谱反射率作为输入,以极限学习机模型为基础构建预测模型,对染色单板的色度参数L^(*)、a^(*)、b^(*)进行预测,运用粒子群算法对ELM权值和阈值进行寻优,并引入非线性惯性权重和新的位置与速度更新策略改进粒子群算法,以消除其易陷入局部最优的缺点。此外,以L^(*)、a^(*)、b^(*)平均绝对误差为评价指标,与基础ELM模型及其他模型作对比,发现优化后的模型平均绝对误差为0.16,测色效果相较于基础ELM的0.68、麻雀算法优化的ELM的0.37等具有明显优势,这对于提高木材染色生产效率具有重要意义。

考虑机场、航空公司与空管需求的机场群离场航班时刻优化

随着中国航空流量的不断增加,机场群内航班延误时间长、延误架次多、机场时刻紧张等问题逐渐暴露,这些问题主要是航班时刻设置不合理所导致。为解决这些问题,需要对机场群内航班时刻进行优化。通过从机场、航空公司、空管3个角度综合考虑,分别以延误时间、航空公司航班时刻调整总方差、管制员总调整量作为优化目标,建立了机场群航班时刻优化模型,并使用权重线性递减的粒子群优化算法实现对模型的求解。以京津冀机场群为例进行分析,使用MATLAB对模型进行寻优。结果表明优化后机场群内总延误时间由77580 min减少至46260 min,航空公司航班时刻调整总方差由447.076减少至63.141,管制员总调整量由467次减少至253次,3个目标均得到了优化。可见该模型权衡了机场、航空公司与空管之间的公平性,为机场群航班时刻的优化提供了理论参考。

一种非线性动态权重的粒子群寻优改进算法

在传统的线性递减惯性权重粒子群优化算法(Linearly Decreasing Inertia Weight Particle Swarm Optimization,LDW-PSO)中,惯性权重通过一个固定的线性递减方式进行调整。这种方法在适应具体问题和反映算法当前状态方面存在局限性。为了克服这些限制,在线性递减权重的基础上引入了幂律分布函数,提出了一种新的自适应权重计算方法。该方法使得惯性权重能够根据迭代次数的增加,按照幂律函数的非线性规律逐渐减小,从而在算法的早期阶段增强全局搜索能力,在后期阶段更侧重于局部搜索。通过这种灵活的权重调整,改进方法能够有效提升粒子群优化算法的性能。为了验证所提出方法的有效性,采用4种基准测试函数进行性能分析。实验结果表明,与传统的线性递减权重方法和标准粒子群优化算法相比,改进后的算法展现了更优的搜索能力和更好的收敛性能。

基于离散粒子群算法的管道保温结构优化研究

针对目前管道保温结构优化算法不稳定、结果优化程度不高的问题,建立以经济效益为目标函数,以满足国家散热损失标准等条件为约束函数的离散型数学模型。以BPSO算法为基础改变其位置更新规则,防止种群进化失效;采用自适应权重增加粒子的全局和局部搜索能力;充分利用模拟退火算法的思想避免出现早熟现象。应用改进的算法分别对普通蒸汽管道和核电站的蒸汽管道进行系统仿真实验。结果表明,该算法能够在满足国家散热损失标准等条件下取得最优解,可以为管道保温结构提供合理的优化方案。

PSO算法下GP-周期随机共振的微弱OFDM信号检测

为了解决传统随机共振系统在微弱正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)信号解调应用中存在的人工选择参数困难、解调效果差的问题,提出一种基于粒子群优化(Particle Swarm Optimization,PWO)算法的GP(Gaussian Potential)-周期随机共振系统的微弱OFDM信号检测方法。该方法利用GP-周期随机系统对OFDM信号经正交变换后的两路高频信号分别进行随机共振,同时运用阻尼参数与信号频率之间的关系对两路信号进行降频处理,使得上下两路信号都能够发生随机共振;然后使用PWO算法对随机共振的系统参数进行优化处理,以使得上下两路信号达到最优的共振效果;最后,将上下两路共振之后的信号合成完成OFDM信号解调,得到最终的数字序列。本文探讨了优化前后GP-周期随机共振系统的共振效果,研究了优化前后GP-周期随机共振诱导下的OFDM系统星座图的聚集程度以及误码率情况,对比分析了经典双稳随机共振、经典三稳随机共振和所提模型对OFDM信号检测的影响。仿真结果表明:相比常用的传统随机共振模型,该方法用于OFDM信号检测的星座图中信号点的聚集程度更高,同时OFDM系统误码率在同样的信噪比下降低50%左右。

基于改进粒子群算法的主动配电网无功优化

随着分布式电源在配电网中的广泛应用,部分地区电压越限、有功网损增加的现象时有发生。但传统算法求解无功优化无法适应当代配电网的要求。因此,提出一种改进的粒子群算法应用于主动配电网无功优化。首先,建立有功损耗、电压偏移和、节点最低电压值的多目标函数,通过线性加权求和的方法将多目标函数转换为单目标。然后,提出一种基于种群集中度概念的惯性权重调整,并在算法的学习因子中引入正弦和余弦控制因子,利用改进后的算法进行主动配电网无功优化。最后,在改进的IEEE33节点上进行仿真,验证所提出算法的可行性、有效性。

基于改进粒子群算法的阻尼惯量自适应控制策略

针对传统虚拟同步发电机控制策略存在暂态调节时间长及稳定性差等问题,提出一种基于改进粒子群算法的阻尼惯量自适应控制策略。首先,通过分析系统受扰动后功角特性,提出阻尼惯量自适应控制策略;然后,利用改进粒子群算法选择控制策略初始值,给出关键参数的选取原则及具体范围;最后,通过与现有控制策略进行对比,分析不同惯量及阻尼下对系统影响并验证控制策略的优越性。结果表明,该策略可有效提高系统稳定性及动态响应性能。

基于巴特沃斯幅频特性的自适应粒子群算法

针对传统粒子群算法存在求解精度低和易陷入局部最优等问题,提出一种基于巴特沃斯幅频特性的自适应粒子群算法(Butterworth amplitude-frequency characteristics based adaptive particle swarm optimization algorithm,BAC-PSO).一方面,借助巴特沃斯幅频特性设计一种惯性权重非线性递减策略,均衡算法中粒子的局部与全局搜索能力;另一方面,通过S型函数的粒子群优化策略和Sigmoid函数改进位置更新方法,进一步提升算法的求解精度.以5个经典的测试函数为基准,将BAC-PSO算法与5种经典粒子群算法的性能进行对比,并将其应用到求解压力容器模型的设计问题中.实验结果表明,相较于其他经典粒子群算法,BAC-PSO算法的求解精度更高,收敛速度更快,稳定性更好.

计及不确定性的随机暂态稳定约束最优潮流

为应对电力系统中不确定性对系统安全稳定造成的显著影响,提出一种计及不确定性的随机暂态稳定约束最优潮流方法。首先,采用威布尔和正态分布分别描述风电和负荷两种不确定性变量。其次,设置相应的置信水平,基于机会约束理论建立相应的概率约束,以期望值形式表达目标函数,从而建立计及不确定性的随机暂态稳定约束最优潮流模型。然后,通过半不变量法和Gram-Charlier级数求取电力系统输出变量的累积分布函数,并利用改进量子粒子群算法进行求解。最后,算例分析验证了所提方法的优越性和有效性。

免疫粒子群算法的测试数据生成

为有效改善粒子群算法进化后期收敛速度慢,克服易陷入局部极值的缺陷,提出一种自适应免疫粒子群算法并在面向路径的测试数据生成中得到应用。本文提出自适应的惯性权重的调整方法和学习因子的调节策略,加快算法的搜索速率;引入免疫算法中的免疫算子,提出抗体的浓度调节机制,使得粒子群的多样性更加丰富,提升算法的寻优能力;通过免疫选择操作,避免算法的早熟收敛;以分支函数叠加法构造适应度函数。实验结果表明,该算法避免了粒子群算法早熟收敛现象的发生,有效地提高了测试数据自动生成的效率。

基于遗传粒子群动态聚类算法的物流柔性分拣系统品规分配

目的针对目前烟草物流配送中心条烟分拣量大,不同条烟品规的分配对订单的总处理时间影响较大的问题,研究平衡各个分拣区品规的分配,提高分拣效率。方法建立以各分区品规相似系数和最小为目标函数的数学模型,并采用改进的遗传粒子群动态聚类(GAPSO-K)算法进行求解。首先,结合各品规分拣量对品规相似系数进行改进,并将其作为适应度函数;然后在粒子群算法中对惯性权重因子进行改进,使其值可以进行自适应改变;最后,在粒子群动态聚类算法中引入遗传算法中的交叉变异扩大解的搜索范围,基于Matlab对文中的其他算法进行求解对比,求得结果在EM-plant中进行仿真验证。结果结合某烟草物流配送中心数据仿真验证,利用GAPSO-K算法处理订单的时间为234.5 s,较传统时间大幅度较少,有效提升了柔性物流分拣效率。结论采用该算法可充分发挥2种算法的优良性,具有更好的收敛性及寻优性,为柔性物流品规分配提供了新思路。

基于多目标粒子群优化算法的动力电池仿生冷板结构优化设计

为了提高锂离子电池的冷却效果,提出一种高度对称的仿生网状流道冷板。首先,利用单因子分析法分析了冷板结构参数对其性能的影响,然后,以冷板的平均温度、温度标准差和冷却液压力损失为性能指标,采用多目标粒子群优化(MOPSO)算法对冷板的结构参数进行了优化,得到性能最优时的流道宽度、流道深度和冷板壁厚分别为9.0 mm、1.5 mm和1.4 mm,对应的平均温度、温度标准差和压力损失分别为33.20℃、1.33℃和65.63 Pa,相比于初始结构参数,优化后的平均温度和温度标准差分别下降1.92℃和0.02℃,但压力损失增大27.10 Pa。最后,在电池模组层面验证了优化结果。