Power quality enhancement in solar power with grid connected system using UPQC

The need to generate pollution free energy has triggered the effect towards the usage of solar energy interconnection with the grid. Consequently, the Photovoltaic (PV) panel interfaced with the grid causes the power quality problems such as a voltage harmonics and voltage distortion etc., Active power filters are the powerful tool for mitigation of harmonics. This work involves the use of single-phase Unified Power Quality Conditioner (UPQC) based on a unit vector template control algorithm for its functions with grid integration of photovoltaic, such as voltage sags/ swell, unit power factor correction, voltage and current harmonic cancelation. The unit vector template control algorithm includes a phase-locked loop (PLL) mechanism that is responsible for avoiding multiple zero crossings during highly distorted grid voltage detection. A unit vector template control with a PLL-based control algorithm is applied to the shunt and series inverters of PV grid connected UPQC. In addition to normalizing voltage and current disturbances, the proposed controller has the functions of phase detection and perfect grid synchronization. It is proposed that the system performance is fully verified by MATLAB simulation with the response of load variation, transient response, THD, voltage swell and sag. The Total Harmonic Distortions (THDs) of proposed grid integration of photovoltaic systems through single-phase unified power quality conditioner (UPQC) obtain the range of IEEE standard.     

Optimal tuning of FOPID controller for higher order process using hybrid approach

Applied Intelligence - This paper proposes an optimal tuning of fractional order proportional integral derivative (FOPID) controller for higher order process using hybrid approach. The proposed...     

FPGA based substantial power evolution controlling strategy for solar and wind forecasting grid connected system

The solar and wind are both the most promising renewable and clean energy sources, the solar stable energy progress and environmental protection have been increasingly noticeable. In this regard, an accurate solar and wind energy prediction is extremely important to avoid large voltage changes to the power grid and to provide a mechanism for the system to optimally manage the generated energy. Wind energy forecasting is widely practiced among modest power systems for high levels of windmills. This paper aims to develop a new hybrid system for wind and solar energy prediction. The proposed hybrid (wind & solar) energy prediction model is based on a Substantial Power Evolution Strategy (SPES) dedicated to short-term forecasting. The proposed forecasting system SPES is implemented using MATLAB. This paper implements the short-term and hybrid power forecasting using Substantial Power Evolution Strategy based on Prediction Intervals (PIs). This feature is one of the major innovations in the proposed hybrid renewable energy forecasting system. The accuracy of the proposed system will be revealed by comparing the results of the corresponding values of the independent forecasting models called persistence models. The designed device presents a real-time application of predicting daily total solar and wind power using any geographic location and environmental conditions using FPGA. Finally, fully developed system packages can be commercialized and/or utilized for further research projects, and researchers can analyze, validate and visualize their models for related fields.     

AI-based solar energy forecasting for smart grid integration

Neural Computing and Applications - Integrating solar energy power into the existing grid system is a challenging task due to the volatile and intermittent nature of this power. Robust energy...     

基于PIC16F877A的太阳能与市电互补照明系统控制器的设计

介绍了一款以单片机PIC16F877A为控制核心的太阳能与市电互补照明系统控制器的设计.通过对蓄电池充电开关、放电开关和市电供电开关的控制,实现了对系统中蓄电池的管理和系统运行控制等功能.对其功能和工作特性进行了测试分析.结果表明,控制器各项功能完成良好,具有较高的实用价值和良好的应用前景.     

UPFC混成控制器设计及其对四川电网稳定性的改善

作为典型的远距离输电系统,四川电网存在严重的暂态稳定问题.为提高其稳定性,首先运用非线性鲁棒控制理论建立了含外部干扰的统一潮流控制器(Unified Power Flow Controller)动态模型.在此模型的基础上,基于脉宽调制(Pulse width modulation)控制技术,提出一类新型混成反馈控制策略,即UPFC串联逆变器的导通角采用非线性H_∞控制策略,其余串、并联控制(调制比和导通角)均采用常规的比例积分(Proportional-Integral)控制.进一步对上述混成控制律中的某些不可测变量进行本地化,保证了控制律的工程实用性.仿真结果表明文中所设计的UPFC控制器较常规PID控制更有效地改善四川电网的动态品质,提高其暂态稳定性.     

小型风光互补型并网发电系统一体化控制器的设计

为了实现小型风光互补性发电系统的并网运行,采用DSP芯片为核心单元,提出了一种一体化控制器的设计方案。本文设计的一体化控制器可以实现最大功率跟踪、蓄电池充放电控制、逆变器输出电压幅值与频率的调节和系统并网控制的功能。从一体化控制器的基本构成入手,分析了控制器实现控制功能的基本过程,根据基本过程设计了各个控制单元的软件程序模块。最后,构建了一个太阳能电池板容量为1000W,风能发电机容量为3000W的风光互补型并网发电系统对一体化控制器的控制性能进行了实验测试。结果表明,一体化控制器整体性能良好,能快速、准确的对系统相关环节施加合理的控制指令,维持系统稳定、安全的运行。     

基于通用内模的变频电网有源电力滤波器自适应重复控制

为了提高变频电网并联型有源电力滤波器(APF)的电流控制性能,针对谐波源的多样性和负载状态的变化,提出了一种通用内模,然后,结合两次坐标变换,通过内模p值的自适应调节,建立了基于通用内模的重复控制器.这种控制器,能够根据电网或负载状态,调整动态响应时间和补偿范围.这样就解决了谐波源或负载的变化引起的补偿效果降低的问题.针对电网频率的大范围变化,又引入了周期自适应参数.为了弥补重复控制动态延迟的缺陷,将并联比例控制器组成复合控制系统,并对该系统的主要特性进行了分析.在飞机变频交流电网并联APF系统中,首先将所提重复控制方法与其他四种方法了进行仿真对比,最后进行了实验验证.仿真和实验结果证明了基于通用内模的复合重复控制策略的有效性和优越性.     

山西电网消纳风电能力的计算分析

山西电网风电并网规模不断增大,电力系统的调峰能力已成为消纳风电的主要因素。结合山西省水电贫乏、火电供热机组增多等特点,并考虑负荷特性、电源特性,分析了山西电网的调峰能力和风电对电网调峰能力的影响,提出了山西电网消纳风电能力的计算方法。在收集各种实际运行数据的基础上,通过计算分析,得到了山西电网消纳风电能力容量范围,并据此提出了电网运行控制措施。通过实践运行,证明此计算分析方法基本正确,达到了提高电网消纳能力的目的。     

An expert system for predicting aeration performance of weirs by using ANFIS

A free overfall jet from a weir plunging into downstream water causes entrainment of the air bubbles if the free overfall jet velocity exceeds a certain critical value and hence aeration occurs. This study investigates the free overfall jets from triangular sharp-crested weirs and effect on their air entrainment rate and the aeration efficiency. An expert system based on adaptive network based fuzzy inference system (ANFIS) was obtained for predicting air entrainment rate and aeration efficiency of weirs. The performance of ANFIS model was compared with multi nonlinear and linear regression models. There were good agreements between the measured values and the values obtained using the ANFIS model.     

An adaptive fusion algorithm based on ANFIS for radar/infrared system

In order to improve tracking ability, an adaptive fusion algorithm based on adaptive neuro-fuzzy inference system (ANFIS) for radar/infrared system is proposed, which combines the merits of fuzzy logic and neural network. Fuzzy adaptive fusion algorithm is a powerful tool to make the actual value of the residual covariance consistent with its theoretical value. To overcome the defect of the dependence on the knowledge of the process and measurement noise statistics of Kalman filter, neural network is introduced, which has the ability to learn from examples and extract the statistical properties of the examples during the training sessions. The fusion system mainly consists of Kalman filters, ANFIS sensor confidence estimators (ASCEs) based on contextual information (CI) theory, knowledge base (KB) and track-to-track fusion algorithms. Experimental data are implemented to train ASCEs to obtain sensor confidence degree. Simulation results show that the algorithm can effectively adjust the system to adapt contextual changes and has strong fusion capability in resisting uncertain information.     

Robust FOPID controller design for fractional‐order delay systems using positive stability region analysis

In this paper, a robust fractional‐order PID (FOPID) controller design method for fractional‐order delay systems is proposed based on positive stability region (PSR) analysis. Firstly, the PSR is presented to improve the existing stability region (SR) in D‐decomposition method. Then, the optimal fractional orders λ and μ of FOPID controller are achieved at the biggest three‐dimensional PSR, which means the best robustness. Given the optimal λ and μ, the other FOPID controller parameters k_p, k_i, k_d can be solved under the control specifications, including gain crossover frequency, phase margin, and an extended flat phase constraint. In addition, the steps of the proposed robust FOPID controller design process are listed at length, and an example is given to illustrate the corresponding steps. At last, the control performances of the obtained robust FOPID controller are compared with some other controllers (PID and FOPI). The simulation results illustrate the superior robustness as well as the transient performance of the proposed control algorithm.     

基于网格的电子投票系统

利用网格、JSP技术设计实现了一个禁止重复投票的电子投票系统.在网格环境中,针对该系统重点讨论了JDBC连接MySql数据库技术、Servlet技术和Cookie技术等,解决了基于MVC模式开发应用系统的一些难题.同时,利用CA认证技术解决了基于网格的电子投票系统的安全性问题.     

进化神经网络PID控制器的研究与应用

提出一种基于进化神经网络的PID控制器设计方法.该控制器主要由3部分组成,第1部分应用神经网络根据控制对象的输入、输出在线调整PID控制器参数.第2部分利用进化算法根据性能指标对神经网络控制器参数进行优化,找出最优的神经网络初始权系数和比例系数.第3部分是传统PID控制器.把该控制器温度控制的仿真对照结果表明,这种控制算法具有结构简单、鲁棒适应性强、进化性能良好的特点.同时还提出一种以快速响应为目标的改进方案.     

基于改进型ANFIS的磁致伸缩液位传感器温度补偿

考虑到磁致伸缩液位传感器在温差变化大的环境中温漂现象严重,且产生温漂的多种因素与温漂的程度呈非线性关系,难以用数学模型表达等问题,建立基于改进型ANFIS的温度补偿系统。该系统采用附加动量算法不断修正ANFIS中的前题参数以避免采用梯度下降算法时易陷入局部极小,训练速度较慢等缺点,提高系统的忽略网络中微小变化的能力。为了验证该温度补偿系统的性能,将其与基于PSO-LSSVM模型和基于BP神经网络的温度补偿系统相比较。分析与实验结果表明,改进型ANFIS模型的温度补偿的最大误差为0.88%,平均误差为0.65%,远小于另外两种补偿方法。使用了改进型ANFIS的温度补偿方法具有较强的泛化能力,能够有效消除温度对磁致伸缩液位传感器的影响。     

基于PIC单片机的太阳能路灯智能控制器

针对太阳能控制系统的特点,探讨了太阳能路灯控制系统各部件的选用,设计了一种基于PIC16F877单片机的智能控制器.提出了可行的太阳能电池最大功率点跟踪方法和合理的蓄电池充放电策略.该控制器具有电路结构简单、可靠性高、实用性强等特点.     

A grid computing based approach for the power system dynamic security assessment

This paper addresses the problem of parallel dynamic security assessment applications from static homogeneous cluster environment to dynamic heterogeneous grid environment. Functional parallelism and data parallelism are supported by each of the message passing interface model and TCP/IP model. To consider the differences in heterogeneous computing resources and complexity of large-scale power system communities, a kernel-based multilevel algorithm is proposed for network partitioning. Since the bottleneck in distributed computation is low speed network communication, a bi-level latency exploitation technique is introduced for numerically solving system differential equations. The proposed grid-based implementation includes the core simulation engine, grid computing middleware, a Python interface and Python front-end utilities. Tests for a 39-bus network, a 4000-bus network and a 10,000-bus network are reported, and the results of these experiments demonstrate that the proposed scheme is able to execute the distributed simulations on computational grid infrastructure and provide efficient parallelism.     

基于太阳能电源的图像采集系统

利用光伏转换与控制技术,将太阳能光伏运用于图像采集上,开发出一套基于太阳能光伏电源的图像采集系统。前级在硬件上采用BUCK型DC-DC电路,软件上提出了固定电压法结合双向扰动观察法的最大功率点跟踪算法,后级图像采集由AVR控制数字摄像头OV7620完成图像采集并传输至上位机。测试结果表明,该系统能够快速、精确、稳定地追踪到太阳能电池板的最大功率点,并且只需稍作修改便可应用于各种需要图像采集的场合。     

Detection of pH neutralization technique in multiple tanks using ANFIS controller

pH neutralization is commonly used in Industry. Limitation of pH has been recognized as an exciting trouble due to the changing in time and non-linear characteristics of the system. because of that, monitoring of pH in neutral region is an essential process. In this paper authors recommend layout method and alertness of Adaptive Neuro-Fuzzy Inference System (ANFIS) using hybrid studying set of rules to enhance the prediction based totally on fractional PI controller. Therefore, this paper deals with multiple tank size and its quantity. Using ANFIS method easy to reduce settling time, disturbance and errors going on in output. This technique produces an efficient output in minimal time. From this result offset and overshoot time is zero, the setting time is below 10 min. This is the best result while comparing other methods.