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.

Dynamic Multi-objective Optimization of Chemical Processes Using Modified BareBones MOPSO Algorithm

Dynamic multi-objective optimization is a complex and difficult research topic of process systems engineering. In this paper,a modified multi-objective bare-bones particle swarm optimization( MOBBPSO) algorithm is proposed that takes advantage of a few parameters of bare-bones algorithm. To avoid premature convergence,Gaussian mutation is introduced; and an adaptive sampling distribution strategy is also used to improve the exploratory capability. Moreover, a circular crowded sorting approach is adopted to improve the uniformity of the population distribution.Finally, by combining the algorithm with control vector parameterization,an approach is proposed to solve the dynamic optimization problems of chemical processes. It is proved that the new algorithm performs better compared with other classic multiobjective optimization algorithms through the results of solving three dynamic optimization problems.

Research on Optimization of Freight Train ATO Based on Elite Competition Multi-Objective Particle Swarm Optimization

In view of the complex problems that freight train ATO (automatic train operation) needs to comprehensively consider punctuality, energy saving and safety, a dynamics model of the freight train operation process is established based on the safety and the freight train dynamics model in the process of its operation. The algorithm of combining elite competition strategy with multi-objective particle swarm optimization technology is introduced, and the winning particles are obtained through the competition between two elite particles to guide the update of other particles, so as to balance the convergence and distribution of multi-objective particle swarm optimization. The performance comparison experimental results verify the superiority of the proposed algorithm. The simulation experiments of the actual line verify the feasibility of the model and the effectiveness of the proposed algorithm.

Interactive Multi-objective Optimization Design for the Pylon Structure of an Airplane

The pylon structure of an airplane is very complex, and its high-fidelity analysis is quite time-consuming. If posterior preference optimization algorithm is used to solve this problem, the huge time consumption will be unacceptable in engineering practice due to the large amount of evaluation needed for the algorithm. So, a new interactive optimization algorithm-interactive multi-objective particle swarm optimization （IMOPSO） is presented. IMOPSO is efficient, simple and operable. The decision-maker can expediently determine the accurate preference in IMOPSO. IMOPSO is used to perform the pylon structure optimization design of an airplane, and a satisfactory design is achieved after only 12 generations of IMOPSO evolutions. Compared with original design, the maximum displacement of the satisfactory design is reduced, and the mass of the satisfactory design is decreased for 22%.

Particle Swarm Optimization Algorithm Based on Chaotic Sequences and Dynamic Self-Adaptive Strategy

To deal with the problems of premature convergence and tending to jump into the local optimum in the traditional particle swarm optimization, a novel improved particle swarm optimization algorithm was proposed. The self-adaptive inertia weight factor was used to accelerate the converging speed, and chaotic sequences were used to tune the acceleration coefficients for the balance between exploration and exploitation. The performance of the proposed algorithm was tested on four classical multi-objective optimization functions by comparing with the non-dominated sorting genetic algorithm and multi-objective particle swarm optimization algorithm. The results verified the effectiveness of the algorithm, which improved the premature convergence problem with faster convergence rate and strong ability to jump out of local optimum.

Dynamic Self-Adaptive Double Population Particle Swarm Optimization Algorithm Based on Lorenz Equation

In order to improve some shortcomings of the standard particle swarm optimization algorithm, such as premature convergence and slow local search speed, a double population particle swarm optimization algorithm based on Lorenz equation and dynamic self-adaptive strategy is proposed. Chaotic sequences produced by Lorenz equation are used to tune the acceleration coefficients for the balance between exploration and exploitation, the dynamic self-adaptive inertia weight factor is used to accelerate the converging speed, and the double population purposes to enhance convergence accuracy. The experiment was carried out with four multi-objective test functions compared with two classical multi-objective algorithms, non-dominated sorting genetic algorithm and multi-objective particle swarm optimization algorithm. The results show that the proposed algorithm has excellent performance with faster convergence rate and strong ability to jump out of local optimum, could use to solve many optimization problems.

Design Optimization of Permanent Magnet Eddy Current Coupler Based on an Intelligence Algorithm

The permanent magnet eddy current coupler(PMEC)solves the problem of flexible connection and speed regulation between the motor and the load and is widely used in electrical transmission systems.It provides torque to the load and generates heat and losses,reducing its energy transfer efficiency.This issue has become an obstacle for PMEC to develop toward a higher power.This paper aims to improve the overall performance of PMEC through multi-objective optimization methods.Firstly,a PMEC modeling method based on the Levenberg-Marquardt back propagation(LMBP)neural network is proposed,aiming at the characteristics of the complex input-output relationship and the strong nonlinearity of PMEC.Then,a novel competition mechanism-based multi-objective particle swarm optimization algorithm(NCMOPSO)is proposed to find the optimal structural parameters of PMEC.Chaotic search and mutation strategies are used to improve the original algorithm,which improves the shortcomings of multi-objective particle swarm optimization(MOPSO),which is too fast to converge into a global optimum,and balances the convergence and diversity of the algorithm.In order to verify the superiority and applicability of the proposed algorithm,it is compared with several popular multi-objective optimization algorithms.Applying them to the optimization model of PMEC,the results show that the proposed algorithm has better comprehensive performance.Finally,a finite element simulation model is established using the optimal structural parameters obtained by the proposed algorithm to verify the optimization results.Compared with the prototype,the optimized PMEC has reduced eddy current losses by 1.7812 kW,increased output torque by 658.5 N·m,and decreased costs by 13%,improving energy transfer efficiency.

Dynamic Allocation of Manufacturing Tasks and Resources in Shared Manufacturing

Shared manufacturing is recognized as a new point-to-point manufac-turing mode in the digital era.Shared manufacturing is referred to as a new man-ufacturing mode to realize the dynamic allocation of manufacturing tasks and resources.Compared with the traditional mode,shared manufacturing offers more abundant manufacturing resources and flexible configuration options.This paper proposes a model based on the description of the dynamic allocation of tasks and resources in the shared manufacturing environment,and the characteristics of shared manufacturing resource allocation.The execution of manufacturing tasks,in which candidate manufacturing resources enter or exit at various time nodes,enables the dynamic allocation of manufacturing tasks and resources.Then non-dominated sorting genetic algorithm(NSGA-II)and multi-objective particle swarm optimization(MOPSO)algorithms are designed to solve the model.The optimal parameter settings for the NSGA-II and MOPSO algorithms have been obtained according to the experiments with various population sizes and iteration numbers.In addition,the proposed model’s efficiency,which considers the entries and exits of manufacturing resources in the shared manufacturing environment,is further demonstrated by the overlap between the outputs of the NSGA-II and MOPSO algorithms for optimal resource allocation.

基于风光互补发电系统的压缩空气混合储能系统容量优化

压缩空气储能系统可以有效减少因风能和太阳能随机性造成的弃风弃光现象,但其动态响应时间长,且存储规模配置不合理会影响其发展。为此首先提出液流电池与压缩空气储能组成混合储能系统解决并网型风光互补发电系统输出波动不稳定的问题;其次基于典型小时负荷、风力机发电功率和光伏发电功率,针对不同场景,以系统最大收益为目标函数,利用猫群算法优化压缩空气储能系统的容量配置;最后分析压缩空气储能系统的额定容量与额定功率对系统最大收益的影响,验证算法可靠性。结果表明,基于风力机与光伏系统的装机功率分别为20 MW和3.42 MW的场景,压缩空气储能系统容量配置为4 MW和46.5 MW∙h时,其经济性最佳,每周可节约购电成本183688.24元,周最大收益为30543.86元。

基于多目标沙猫群算法的含风光储配电网无功优化

针对现有智能优化算法在求解配电网无功优化时存在的收敛速度慢、易陷入局部最优解等问题,提出一种基于多目标沙猫群算法(MOSCSO)的含风光储配电网无功优化方法.MOSCSO融合了多目标算法中外部储存集的更新和选择机制,具有较好的全局寻优能力,而沙猫群算法(SCSO)特有的搜索和攻击的种群更新方式保证了其具有较快收敛速度和较好寻优能力.建立储能设施(ESS)作为控制变量的IEEE 33节点系统数学模型,应用MOSCSO进行仿真验证.结果表明,本文所提方法在平衡风光发电系统的同时能够降低网损和提高电网稳定性,通过与传统算法比较,验证了MOSCSO在无功优化模型上的有效性和稳定性.

基于SCSO-SVM算法的光伏组件故障识别

光伏阵列通常被安装在恶劣的室外环境中,因此在运行过程中易发生故障。为了准确识别光伏阵列的故障类型,提出沙猫群优化支持向量机(sand cat swarm optimization support vector machine,SCSO-SVM)用于光伏组件故障识别,且对比支持向量机(support vector machine,SVM)、粒子群优化支持向量机(particle swarm optimized support vector machine,PSO-SVM)、遗传优化支持向量机(genetic optimized support vector machine,GA-SVM)、麻雀优化支持向量机(sparrow optimized support vector machine,SSA-SVM)、灰狼优化支持向量机(gray wolf optimized support vector machine,GWO-SVM)和鲸鱼优化支持向量机(whale optimized support vector machine,WOA-SVM)算法。首先,六种SVM混合算法都克服了SVM诊断结果易受参数初始值影响的缺点,识别精度相较传统SVM算法都有所提升,但是识别时间都增加。其次,7种算法中SCSO-SVM识别效果最好,克服了SVM易受参数初始值的影响,相较SVM识别精度提高了约9.4594%;是因为更能有效找到SVM惩罚因子和核函数参数。然后,对于同一种算法而言,算法的识别精度是随输入特征减少而降低的,是因为输入特征越少,越不能有效表征光伏组件在不同故障类型下的输出属性。但算法的识别时间却不是随输入特征减少而减短。所以选取合适的输入特征才能兼顾算法的故障识别准确率和效率。最后,发现七种算法的识别效果依赖于数据集的影响。原因可能是各个算法参数选择过多导致泛化性有差异,且依赖参数初始值选择。

改进猫群算法在车辆配送路径优化中的应用研究

为解决在生鲜农产品的车辆配送过程中存在的成本高、碳排放高的问题,以顾客满意度最高和总配送成本最低为目标,构建低碳冷链生鲜农产品的车辆配送路径优化模型。首先,通过多种方法对猫群算法进行优化;然后,用优化的猫群算法对模型进行求解。通过仿真实验对车辆配送路径优化前后效果进行分析,验证了所构建模型的可行性。结果表明,所构建的模型能有效地解决车辆配送的路径优化问题;与传统车辆配送的路径规划方法相比,采用所构建的车辆路径优化模型,车辆配送总路径和碳排放量都有一定程度的改善;车辆总配送路径长度缩短了489.77km、车辆碳排放量降低了21.4%。该方法能有效降低车辆配送过程的总成本和碳排放量,可在一定程度上提高车辆的利用效率和物流企业的市场竞争力。

一种冲击噪声下的多目标跟踪算法

针对现有的子空间类多目标跟踪算法无法对相干目标进行有效跟踪,传统的动态跟踪方法在冲击噪声环境下失效的问题,提出了一种冲击噪声下的多目标跟踪算法。构造了一种新的零记忆非线性处理方法实现去冲击,推导得到了基于协方差矩阵更新的极大似然多目标跟踪方程,并设计了一种量子猫群算法,对其进行快速准确求解,实现了在恶劣噪声环境下的鲁棒多目标跟踪。仿真结果表明,所设计的算法突破了已有跟踪方法的性能和应用局限。本文分析结果可用于指导被动雷达和感知系统的跟踪模块设计。

基于沙猫群优化算法的拱坝热学参数反演分析

在混凝土温度场计算中,热学参数对计算结果的准确性有着很大影响。为了得到更加符合现场实际情况的热学参数值,提出了一种基于沙猫群优化算法的拱坝热学参数反演方法。通过12种不同的测试函数,验证了沙猫群优化算法的性能相比于其他3种传统优化算法有着一定的优势。同时,考虑到环境温度变化和多级冷却通水的影响,应用沙猫群优化算法对白鹤滩拱坝混凝土浇筑仓热学参数进行了反演。通过反演结果证明了沙猫群优化算法应用到工程实践中的合理性和可靠性,可以满足实际工程的精度需求。

Milling Parameters Optimization of Al-Li Alloy Thin-Wall Workpieces Using Response Surface Methodology and Particle Swarm Optimization

To improve the milling surface quality of the Al-Li alloy thin-wall workpieces and reduce the cutting energy consumption.Experimental research on the milling processing of AA2195 Al-Li alloy thin-wall workpieces based on Response Surface Methodology was carried out.The single factor and interaction of milling parameters on surface roughness and specific cutting energy were analyzed,and the multi-objective optimization model was constructed.The Multiobjective Particle Swarm Optimization algorithm introducing the Chaos Local Search algorithm and the adaptive inertial weight was applied to determine the optimal combination of milling parameters.It was observed that surface roughness was mainly influenced by feed per tooth,and specific cutting energy was negatively correlated with feed per tooth,radial cutting depth and axial cutting depth,while cutting speed has a non-significant influence on specific cutting energy.The optimal combination of milling parameters with different priorities was obtained.The experimental results showed that the maximum relative error of measured and predicted values was 8.05%,and the model had high reliability,which ensured the low surface roughness and cutting energy consumption.It was of great guiding significance for the success of Al-Li alloy thin-wall milling with a high precision and energy efficiency.

Optimal Allocation of Comprehensive Resources for Large-Scale Access of Electric Kiln to the Distribution Network

With the significant progress of the“coal to electricity”project,the electric kiln equipment began to be connected to the distribution network on a large scale,which caused power quality problems such as low voltage,high harmonic distortion rate,and high reactive power loss.This paper proposes a two-stage power grid comprehensive resource optimization configuration model.A multi-objective optimization solution based on the joint simulation platform of Matlab and OpenDSS is developed.The solution aims to control harmonics and optimize reactive power.In the first stage,a multi-objective optimization model is established to minimize the active network loss,voltage deviation,and equipment cost under the constraint conditions of voltage margin,power factor,and reactive power compensation capacity.Furthermore,the first stage uses a particle swarm optimization(PSO)algorithm to optimize the location and capacity of both series and parallel compensation devices in the distribution network.In the second stage,the optimal configuration model of the active power filter assumes the cost of the APF as the objective function and takes the harmonic voltage content rate,the total voltage distortion rate,and the allowable harmonic current as the constraint conditions.The proposed solution eliminates the harmonics by uniformly configuring active filters in the distribution network and centrally control harmonics at the system level.Finally,taking the IEEE33 distribution network as the object and considering the change of electric furnace permeability in the range of 20%–50%,the simulation results show that the proposed algorithm effectively reduces the distribution network’s loss,its harmonic content and significantly improve its voltage.

Performance Evaluation and Comparison of Multi - Objective Optimization Algorithms for the Analytical Design of Switched Reluctance Machines

This paper systematically evaluates and compares three well-engineered and popular multi-objective optimization algorithms for the design of switched reluctance machines.The multi-physics and multi-objective nature of electric machine design problems are discussed,followed by benchmark studies comparing generic algorithms(GA),differential evolution(DE)algorithms and particle swarm optimizations(PSO)on a 6/4 switched reluctance machine design with seven independent variables and a strong nonlinear multi-objective Pareto front.To better quantify the quality of the Pareto fronts,five primary quality indicators are employed to serve as the algorithm testing metrics.The results show that the three algorithms have similar performances when the optimization employs only a small number of candidate designs or ultimately,a significant amount of candidate designs.However,DE tends to perform better in terms of convergence speed and the quality of Pareto front when a relatively modest amount of candidates are considered.

基于ISCSO-LSTM模型的刀具磨损预测

为进一步提高刀具磨损量预测模型的准确度,实现对刀具加工过程的在线监控。提出一种基于改进的沙猫算法(improved sand cat swarm optimization,ISCSO)和长短期记忆神经网络(long short-term memory,LSTM)的刀具磨损量预测模型。利用刀具的加速度振动信号为输入样本,应用长短期记忆神经网络对铣刀磨损值进行预测。针对沙猫算法收敛精度低等问题,引入混沌映射、非线性收敛因子和对立点检测机制,利用改进的沙猫算法优化长短期记忆神经网络的参数。实验结果表明ISCSO-LSTM模型的刀具磨损预测精度明显高于LSTM模型。

改进沙猫群优化算法优化堆叠降噪自动编码器的发动机故障诊断

车辆发动机振动信号受到噪声干扰,影响故障诊断精度,而堆叠降噪自动编码器(SDAE)可以有效抑制噪声干扰,但SDAE模型超参数对诊断性能影响较大,不合理的模型超参数容易引起SDAE诊断性能不佳。因此,文中采用一种新型沙猫群优化算法(SCSO)对SDAE参数进行优化选取。考虑到沙猫群优化算法(SCSO)中沙猫群种群缺乏变异机制的缺陷,在其探索阶段和开发阶段分别引入柯西变异机制和高斯变异机制,得到了改进沙猫群优化算法(ISCSO),并提出了SCSO优化SDAE的发动机故障诊断方法。发动机故障诊断实例结果表明:与其余5种方法相比,所提方法的平均诊断精度提高了1.47%~6.5%,平均耗时缩短了5.29~19.44 s。

基于复合基尼指数和最大相关峭度特征模态分解的轴承故障诊断算法

最大相关峭度特征模态分解可以有效去除冗余信息,实现故障特征增强,但是其效果受分解模态数量、初始化滤波器个数和滤波器长度的影响。针对此问题,文章提出了一种基于复合基尼指数(Compound Gini Index,CGI)与最大相关峭度特征模态分解(Maximum Correlated Kurtosis Feature Mode Decomposition,MCKFMD)的轴承故障诊断方法。首先,将时域平方基尼指数和频域平方基尼指数结合,构建了一种能够同时量化时域和频域周期性脉冲丰富度的新稀疏测度指标,命名为复合基尼指数,并对其性能特性进行评估验证;其次,使用CGI作为沙丘猫群优化算法(Sand Cat Swarm Optimization,SCSO)寻优的适应度函数,快速准确地得到MCKFMD的最优参数组合,实现故障信号的自适应分解;最后,利用CGI选取最优模态,并进行希尔伯特包络解调,实现故障特征提取。通过仿真信号和试验信号验证了所提方法的有效性。对比性研究表明,与参数优化VMD和固定参数MCKFMD相比,文章所提方法在提取周期性故障特征方面更为有效。