Hybrid Power Bank Deployment Model for Energy Supply Coverage Optimization in Industrial Wireless Sensor Network

Energy supply is one of the most critical challenges of wireless sensor networks(WSNs)and industrial wireless sensor networks(IWSNs).While research on coverage optimization problem(COP)centers on the network’s monitoring coverage,this research focuses on the power banks’energy supply coverage.The study of 2-D and 3-D spaces is typical in IWSN,with the realistic environment being more complex with obstacles(i.e.,machines).A 3-D surface is the field of interest(FOI)in this work with the established hybrid power bank deployment model for the energy supply COP optimization of IWSN.The hybrid power bank deployment model is highly adaptive and flexible for new or existing plants already using the IWSN system.The model improves the power supply to a more considerable extent with the least number of power bank deployments.The main innovation in this work is the utilization of a more practical surface model with obstacles and training while improving the convergence speed and quality of the heuristic algorithm.An overall probabilistic coverage rate analysis of every point on the FOI is provided,not limiting the scope to target points or areas.Bresenham’s algorithm is extended from 2-D to 3-D surface to enhance the probabilistic covering model for coverage measurement.A dynamic search strategy(DSS)is proposed to modify the artificial bee colony(ABC)and balance the exploration and exploitation ability for better convergence toward eliminating NP-hard deployment problems.Further,the cellular automata(CA)is utilized to enhance the convergence speed.The case study based on two typical FOI in the IWSN shows that the CA scheme effectively speeds up the optimization process.Comparative experiments are conducted on four benchmark functions to validate the effectiveness of the proposed method.The experimental results show that the proposed algorithm outperforms the ABC and gbest-guided ABC(GABC)algorithms.The results show that the proposed energy coverage optimization method based on the hybrid power bank deployment model generates more accurate results than the results obtained by similar algorithms(i.e.,ABC,GABC).The proposed model is,therefore,effective and efficient for optimization in the IWSN.

Comparison of Earnings Power between State Commercial Banks and Stock Banks

As earnings power is one of the primary capacities for commercial banks, by analyzing several indexes on banks'o peration performance, this article compared the earnings power between the state banks and the stock banks in China. Through the analysis, some problems of domestic banks may be found and pointed out that the commercial bank should stress on the target of profit maximum to avoid the domancial risks. With enough earnings power,the domestic banks can take the challenge with those foreign banks entering domestic money market.

Effect of Switching Devices on Power Quality and Transient Voltage Suppression Using Capacitor Bank Model

The main purpose of the electrical power system is to transport and distribute energy generated by the central power plants in a safe and reliable manner to the customer premises. Most of the electrical equipment is exposed within the open which suggests they can be vulnerable to lightning strikes, road dwindling, windstorms, and a few engineering activities with the potential of causing different degrees of damage to the electrical equipment. One of the ways to guard the equipment is to deploy switching devices. However, the operations of most of these switching devices produce oscillatory transient in the electrical transmission and distribution systems which result in voltage, current, and frequency fluctuations in the load. This paper investigates the effect of switching devices on power quality and proposes a positive sequence voltage power transient suppression technique that can spontaneously improve the distorted voltage at the instant of capacitor switching using the capacitor line model as a case study. MATLAB/Simulink software was utilized for the analysis on an electrical network model with bus voltages of 69 kV/12.47 kV and 480 V. The results showed that, during switching operations, the positive sequence voltage power detector block produces ripple-free accurate results.

3D机器视觉在充电宝包装系统中的应用研究

为了提高包装机械智能化程度和生产效率,设计并实现了一种基于3D机器视觉的充电宝智能装配和包装控制系统。该系统主要包括自动装配、自动贴标、2D机器视觉质检、3D机器视觉包装和立体仓储等功能模块。对系统的硬件和软件进行了论述,重点对3D相机的编程进行了研究和阐述。通过实验证明,所设计系统的功能实现率均在99%以上。基于3D机器视觉的充电宝智能装配和包装控制系统可以提高包装机械的智能化和柔性化水平,在提高生产效率的同时,大大降低企业人力成本。

背壳式充电宝的创新设计研究

目前消费者对移动电子数码产品的充电需求发生了变化,为了解决手机充电的便携性问题,研究创新性地提出了背壳式充电宝的概念,以无线充电的方式,加上背壳组件的相互配合,即可在不同充电环境下完成自由切换。文章通过对背壳式充电宝的外观设计、结构设计、功能设计等角度阐述设计思路,同时运用Solidworks软件展现了手机外壳的形状,采用电磁感应技术实现充电宝的无线充电功能,并从设备的整体设计出发,以配件间的搭配及工作原理来阐释。以期对充电宝设计提供一定的借鉴。

基于PSD特征的FBCCA脑电信号识别方法

当前基于稳态视觉诱发电位(steady-state visual evoked potential,SSVEP)的脑机接口(brain-computer interfaces,BCIs)使用的都是单一识别算法,针对不同时间长度的识别准确率较低。提出了一种基于滤波器组的典型相关分析(filter bank canonical correlation analysis,FBCCA)与功率谱密度(power spectral density,PSD)分析相结合的SSVEP识别算法,可以提高SSVEP识别的普适性与准确率。该方法使用FBCCA寻找高相似度的参考频率信号,再通过多组PSD分析来锁定最终的响应频率,完成频率识别。该方法无需经过训练就能得到较高的识别准确率。实验结果表明:在刺激时长为1 s时,该方法能达到86.61%的准确率,比PSD分析方法提升了5.44%,比典型相关性分析方法(canonical correlation analysis,CCA)提升了10.38%的准确率,比FBCCA提升了8.86%的准确率。

基于DC-BANK系统的变频器抗“晃电”技术研究

"晃电"对煤化工企业的正常运行有重大影响,轻则使部分电动机、变频器和接触器跳闸或停止工作,造成企业生产的中断,重则发生爆炸等设备事故和人身安全事故。因此,针对发生的"晃电"事故,采用DC-BANK不间断电源系统可以保证变频器在电网发生"晃电"的情况下,负载电动机转速及转矩不变,从而避免了因系统电压波动而造成的电动机输出力矩的变化,保证了工艺参数不发生较大变化,达到了抗晃电的目的,本文利用MATLAB仿真证明了直流支撑系统的可行性。

京东京造自有品牌顾客在线评论分析--以京东京造充电宝为例

当前自有品牌已成为提升零售企业核心竞争力的战略选择。目前中国很多零售商尝试开发自有品牌产品。京东依托京造品牌效应,近几年来发展势头强劲。本文主要采用python数据挖掘技术,以京东京造充电宝为例,挖掘在线评论中质量、价格、服务、物流四方面的评论内容并深入进行剖析。结果表明,京东京造充电宝在上述四方面均存在问题,建议京东京造自有品牌应加大研发投入、加强成本管理、完善服务体系、打造智慧物流,也为国内其他电子商务企业开发自有品牌提供借鉴。

移动电源质量状况分析及改进建议

移动电源(包括带有无线充电器的移动电源)作为智能手表、智能手机、平板电脑、笔记本电脑等的“加油站”,为消费者的生产生活提供了极大的便利,但同时也存在一定的安全风险。为此,国家市场监督管理总局发布公告,自2023年8月1日起对锂离子电池和电池组、移动电源实施CCC认证管理。本文对移动电源在强制性认证检测中,GB 4943.1—2022《音视频、信息技术和通信技术设备第1部分:安全要求》标准测试里容易出现不合格的项目进行了分析并给出相关的改进建议,以便大家在日后的生产研发和认证检测过程中能够更为顺利地进行。

无功补偿技术在电力电气自动化中的应用研究

在现代电力系统中,无功电力管理的有效性对于维持电网的稳定性和效率至关重要.通过探讨无功补偿技术在电力电气自动化中的应用,以及这些技术如何优化电能质量,减少能源损耗,并提高系统的经济性和可靠性.首先概述了无功补偿技术的基本类型,包括静态无功发生器(SVG)、电容器组和同步补偿器,强调了它们在适应电网需求和提高传输效率方面的独特优势.随后,深入讨论了无功补偿技术的先进发展,如智能化无功补偿、自适应控制策略,以及新型材料和设备的应用,突出了这些技术在提高电力系统效率和灵活性方面的重大贡献.此外,还探讨了无功补偿技术在智能电网整合、提高电能质量、降低能源损耗和提高系统稳定性方面的实际应用.最后,对无功补偿技术的未来发展进行了展望,指出技术融合和智能化应用将是推动电力电气自动化领域发展的关键因素,预期无功补偿技术将在构建更高效、可靠和可持续的电力系统中发挥更加显著的作用.

抽水蓄能电站库区淹没与库岸稳定分析系统研发及应用

为进一步加快构建新型电力系统,促进抽水蓄能电站数字化转型。笔者通过运用地理信息系统(geographic information system,GIS)技术和数字高程模型(digital elevation model,DEM)建立抽水蓄能电站库区淹没与库岸稳定分析系统,并从系统的技术结构、三维可视化、库区淹没分析、库区浸没分析和库区塌岸分析等方面分析系统模块建设及其功能实现。结果表明,该系统可实现库区淹没范围、库区浸没范围和库区塌岸预测范围边界线的三维模拟分析及实时动态演示,相关的土地利用数据快速整合评估等。该系统可为合理确定抽水蓄能电站水库大坝位置,制定征地拆迁、土地赔偿、移民安置等方案提供科学的决策依据。

一种带自学习功能的DC-BANK系统投切控制策略研究

电网"晃电"易导致变频器低压跳闸,给连续型生产企业造成严重影响。针对传统DC-BANK系统"晃电"检测智能化程序低,固定压差投切方案不能充分减小投切动作对电机正常工作的影响,设计一种含电网电能质量监测、带自学习功能的投切控制策略。仿真结果表明,新型带自学习功能的DC-BANK系统投切控制器不再局限于单纯依靠对母线电压中东的检测,对电压暂降反应更快。基于该控制器对于母线电压跌落的预判和近压投切能减小固定压差投切对于电机系统正常工作的影响,有利于系统的持续稳定工作,适用于对电能质量要求更高的变频器系统抗"晃电"改造。

Efficient Choice of a Multilevel Inverter for Integration on a Hybrid Wind-Solar Power Station

DC/AC converters are very important components that have to be chosen efficiently for each type of power station. In this article, we present in details, a comparison between three different architectures of multilevel inverters, the flying capacitor multilevel inverter (FCMLI), the diode clamped multilevel inverter (DCMLI), and the cascaded H-bridge multilevel inverter (CHMLI). Thus the comparison is focused on the output voltage quality, the complexity of the power circuits, the cost of implementation, and the influence on a power bank inside the renewable power station. We also investigate trough simulation the efficient number of levels and suitable characteristics for the CHMLI that showed the most promising performance. The study uses Matlab Simulink platform as a tool of simulation, and aim to choose the most qualified inverter, for a potential insertion on a hybrid renewable energy platform (wind-solar). In all the simulations we use the same PWM control type (SPWM).

Microcontroller Control of Reactive Power Compensation for Growing Industrial Loads

Many industrial installations in developing countries start-up as small factories, without regard for the need of compensation of reactive power, leading to significant financial losses in the long term. By improving the power factor, the customer can reduce its power demand and potentially increase efficiency of their equipment. A PIC microcontroller is used to switch capacitor banks to compensate for the reactive power. In order to determine the size of the capacitor bank needed, the microcontroller calculates the phase difference between the voltage and the current. The results obtained based on the lagging power factor for three test loads show an improvement in the power factor from 0.52 to 0.96 under different test load conditions.

Particle swarm optimization algorithm for simultaneous optimal placement and sizing of shunt active power conditioner(APC)and shunt capacitor in harmonic distorted distribution system

Due to development of distribution systems and increase in electricity demand,the use of capacitor banks increases.From the other point of view,nonlinear loads generate and inject considerable harmonic currents into power system.Under this condition if capacitor banks are not properly selected and placed in the power system,they could amplify and propagate these harmonics and deteriorate power quality to unacceptable levels.With attention of disadvantages of passive filters,such as occurring resonance,nowadays the usage of this type of harmonic compensator is restricted.On the other side,one of parallel multi-function compensating devices which are recently used in distribution system to mitigate voltage sag and harmonic distortion,performs power factor correction,and improves the overall power quality as active power conditioner(APC).Therefore,the utilization of APC in harmonic distorted system can affect and change the optimal location and size of shunt capacitor bank under harmonic distortion condition.This paper presents an optimization algorithm for improvement of power quality using simultaneous optimal placement and sizing of APC and shunt capacitor banks in radial distribution networks in the presence of voltage and current harmonics.The algorithm is based on particle swarm optimization(PSO).The objective function includes the cost of power losses,energy losses and those of the capacitor banks and APCs.

Optimum Simultaneous Allocation of Renewable Energy DG and Capacitor Banks in Radial Distribution Network

Nowadays the optimal allocation of distributed generation (DG) in the distribution network becomes the popular research area in restructuring of power system. The capacitor banks introduced in the distribution networks for reactive power compensation also have the capacity to minimize the real and reactive power losses occurred in the system. Hence, this research integrates the allocation of renewable energy DG and capacitor banks in the radial distribution network to minimize the real power loss occurred in the system. A two-stage methodology is used for simultaneous allocation of renewable DG and capacitor banks. The optimum location of renewable energy DG and capacitor banks is determined using the distributed generation sitting index (DGSI) ranking method and the optimum sizing of DG and capacitor banks is found out for simultaneous placement using weight improved particle swarm optimization algorithm (WIPSO) and self adaptive differential evolution algorithm (SADE). This two-stage methodology reduces the burden of SADE and WIPSO algorithm, by using the DGSI index in determining the optimal location. Hence the computational time gets reduced which makes them suitable for online applications. By using the above methodology, a comprehensive performance analysis is done on IEEE 33 bus and 69 bus RDNs and the results are discussed in detail.

人民币国际化与央行角色:基于货币政策有效性视角的分析

与现有货币国际化理论预期以及德国和日本的货币国际化实践不同,“政府力量”在人民币国际化过程中发挥着核心作用。结合中国特殊的政治经济背景,形成这一差异现象的原因在于,有管理的汇率制度和基于国内利率层面的金融抑制政策是限制中国央行货币政策有效性提升的两大障碍,推进人民币国际化需要以更加灵活的汇率制度和利率自由化为政策前提,从而能够有效提升中国央行货币政策的有效性。中国央行积极推进人民币国际化遵循着“人民币国际化→国内金融体系市场化改革→货币政策有效提升”的政策逻辑。与此同时,人民币国际化政策并未给国内经济部门带来净损失,从而为中国政府认可并落实推进人民币国际化政策提供了重要条件。

新型电力系统环境下FBMC系统信道估计

移动无线通信在新型电力系统的发电、输电、配电、变电、用电等环节中都有着广泛的应用场景,滤波器组多载波(Filter Bank Multi-carrier,FBMC)技术作为一种新型无线通信方式,相比4G应用的正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术有着频带利用率高、带外功率泄漏低、无须循环前缀等优点,但也存在计算复杂度高、虚部干扰难以消除等缺点,对信道估计环节接收信号的恢复造成影响。为高效解决FBMC系统信道估计问题,结合压缩感知思想,利用稀疏度自适应匹配追踪(Sparse Adaptive Match Pursuit,SAMP)算法与离散傅里叶变换(Discrete Fourier Transform,DFT)算法,设计并完成信号恢复实验以及FBMC系统信道估计仿真实验,随机信号恢复实验验证了SAMP算法的重构性能,在FBMC系统信道估计仿真实验中,将提出的算法与SAMP、子空间追踪(Subspace Pursuit,SP)、正交匹配追踪(Orthogonal Matching Pursuit,OMP)等常见压缩感知算法充分比较,结果证明该算法相比其他传统算法有更低的误码率和更低的均方误差。