Maximum Power Point Tracking Using Disturbance Observer-Based Sliding Mode Control for Estimation of Solar Array Voltage

Abstract

The output power of solar panel in photovoltaic systems is affected by changes in environmental and load conditions. Most currently developed MPPT control algorithms require measurements of panel output voltage, output current, and converter output voltage. In this paper, a new scheme that can cater to uncertainties in the environmental and load condition, is developed using a disturbance observer-based sliding mode control (DOSMC). The proposed DOSMC scheme obviates the need of using a panel output voltage sensor. The proposed scheme does not use a discontinuous control, thereby overcoming the problems of chatter normally associated with the conventional sliding mode control (SMC). The stability is proven in the sense of ultimate boundedness. The proposed scheme is validated by extensive simulation and laboratory experimentation under various scenarios of irradiation, temperature, and load conditions and compared with two existing popular schemes.     

EIP移动接入平台设计与实现*

介绍了企业信息门户(Enterprise Information Portal, EIP)短消息形式无线接入平台的设计。提出的符合计算机部件结构规范的软、硬件层次设计方案,实现了移动通信终端与EIP Web服务器之间信息交互的有效渠道,具有实际的应用前景。     

SBR系统中的模糊神经网络控制器设计

将模糊控制与神经网络相结合,设计4层模糊神经网络控制器,分析其结构及算法。利用神经网络的自学习能力,在线动态调整模糊变量的隶属函数,优化控制规则,并对曝气池中溶解氧浓度与活性污泥浓度进行控制。通过Matlab对溶解氧的控制进行数字仿真实验,结果表明,具有学习能力的模糊神经网络控制可在污水处理系统的应用中获得更优的性能。     

改进的水处理预估模型的研究和应用

针对水处理中溶解氧的传质过程存在严重的滞后问题．提出了基于单神经元PID控制的水处理预估模型。由于在标准状况下溶解氧的传质过程近似为一阶纯滞后过程,采用了Smith预估器作为补偿环节。将基于有监督Delta学习规则的单神经元PID作为控制器,在线不断调整PID参数,通过仿真研究该模型具有很好的控制效果。最后在西门子PLC下实现此模型的工程应用。     

三级过滤对复合型微污染地下水净化效能研究

目的研究接触氧化法的工艺过程与运行参数,以使复合型微污染地下水达到饮用水标准．方法用地下水配加MnSO4·5H2O,FeSO4·7H2O,NH4Cl和腐植酸、尿素、淀粉,模拟复合型微污染地下水,采用锰砂-陶粒-锰砂三级接触氧化过滤法处理,滤层总厚度1．5m,滤速1m／h．结果经过三级曝气、过滤后,出水主要指标达到饮用水标准．Fen氧化还原电位低,只采用跌水曝气DO值已满足要求,平均去除率为95．36％．CODMn质量浓度相对较低,在只跌水曝气时已达标,平均去除率为44．21％,增大曝气量后出水质量浓度更低,平均去除率为53．69％．采用简单的跌水曝气方式时,出水锰和氨氮质量浓度均较高,经增加曝气强度后,出水氨氮、锰逐渐开始达标,达标后平均去除率分别为97．22％和96．50％．结论三级曝气、过滤接触氧化法处理复合型微污染地下水能取得良好的净化效果,其中DO对锰和氨氮有较大影响．     

改变缺氧池容积强化A^2/O工艺脱氮除磷效率

采用实验室规模连续流厌氧-缺氧-好氧(A/A/O)工艺处理人工模拟生活污水,考察了不同碳氮比(C/N)和溶解氧(DO)工况下改变缺氧池容积对A^2/O工艺脱氮除磷效果的影响。结果表明,在低C/N和好氧阶段DO含量较低时,增大缺氧池容积有利于提高TN的去除率和除磷效率,在COD/ρ(TN)(ρ(TN)≈40 mg/L)约为7,DO的质量浓度在0.9~1.2 mg/L的条件下,缺氧池容积增加1倍,TN去除率可达71.1%,PO4^3--P去除率可达94.0%;在高C/N和好氧阶段DO含量较高时,增大缺氧池容积在提高TN去除率和改善出水水质方面效果不显著。     

一种水质监测单片机系统的软硬件开发

介绍了一种由C51单片机控制的水质在线测量系统，对该系统的控制器硬件结构进行了说明，介绍了软件的总体结构和设计方法，并分析了系统液晶显示的模块化设计。通过与传统水质测量方法的比较，说明了该系统的优越性及应用价值。     

基于模糊控制的污水处理实验研究

分析了污水处理中溶解氧控制和化学需氧控制的重要性及复杂性.针对溶解氧量和化学需氧量这两个参数的变化无确定的规律可循的特点,提出用模糊控制的方法控制污水处理中的溶解氧量和化学需氧量.对溶解氧量和化学需氧量分别设计了双输入的模糊控制器,并且设计了以单片机为核心的模糊控制系统.实验结果表明,该控制系统能够保证污水处理后达标排放.     

Effect of dissolved oxygen concentration on nitrogen removal and electricity generation in self pH-buffer microbial fuel cell

A double-chamber self pH-buffer microbial fuel cell (MFC) was used to investigate the effect of dissolved oxygen (DO) concentration on cathodic nitrification coupled with anodic denitrification MFC. It was found that nitrogen and COD removal, electricity generation were positively correlated with DO concentration in the cathode chamber. When total inorganic nitrogen of influent was 202.51 ± 7.82 mg/L at DO 6.8 mg/L, the maximum voltage output was 282 mV and the maximum power density was 149.76 mW/m². After 82 h operation, the highest removal rate of total inorganic nitrogen was 91.71 ± 0.38%. Electrochemical impedance spectroscopy (EIS) test showed that the internal resistance of the reactor with different DO concentration was related to the diffusion internal resistance. The data of bacterial analysis in the cathode chamber revealed that there were not only ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB), but also a large number of exoelectrogens. Compared with the traditional biological denitrification and related MFC denitrification research, this method does not need pH-buffer solution and external circulation device through the anion exchange membrane (AEM). It can generate electricity and remove nitrogen simultaneously, and the oxygen utilization rate in the cathode can also be enhanced.     

污水处理过程的自适应控制

把自适应控制方法应用到污水生化处理过程中,主要是对溶解氧浓度的控制。使用双线性模型来简化溶解氧动态,对于一些不可以直接测量得到的重要过程参数,采用递推最小二乘算法来估计得到,并设置一步预测输出为期望的输出,从而得到对溶解氧浓度的最小方差自校正控制方案。仿真结果说明了空气流量和氧气吸收率(OUR)对溶解氧浓度的影响。