遮光法槽式聚光系统追光传感模块设计

使用几何光学分析法对槽式聚光系统的太阳入射光与聚光器法线夹角最大允许值进了讨论,并给出了最大值的计算公式。讨论了遮光法追光传感模块的工作原理,推导出了遮光板高度的计算公式。通过电路设计把光敏电阻阻值转换成电压信号,经过AD转换后,使用单片机进行数据处理。讨论了的东西光敏电阻转换后的ADC值与判决阈值ADC_th对比产生的4种不同结果与太阳位置的判断方法,并编写单片机程序实现了该算法。经测试表明,制作的追光模块能够控制槽式聚光系统正确追光。     

Numerical investigation of thermal performance of heat loss of parabolic trough receiver

Based on the analysis of computation methods and heat transfer processes of the parabolic trough receiver running in steady state, a two-dimensional empirical model was developed to investigate the thermal performance of heat loss of parabolic trough receivers under steady state equilibrium. A numerical simulation was conducted for the parabolic trough receiver involved in a literature. Comparisons between numerical and experimental results show that the empirical model is accurate enough and can be used to...     

Evaluation of solar aided biomass power generation systems with parabolic trough field

Solar and biomass are both renewable energy resources.Using biomass as fuel is becoming more and more attractive after governments increase the tariff for the electricity from the renewable sources.However the costs of power from a biomass power generation plant depend greatly on the availability and quality of the biomass resource.The commercialization of solar alone thermal power generation is hindered by its high initial investment and low thermal efficiency.In this paper,a concept of integrating solar i...     

Modelling and dynamic simulation of a parabolic trough power plant

Investigational dynamic simulations of an existing 50 MW_el parabolic trough solar thermal power plant in Spain are carried out during clear days and slightly cloudy periods. This work is the first research, which presents a detail dynamic model of a parabolic trough power plant. Besides the thermal energy storage system and solar field, the developed model describes the heat transfer fluid and steam/water paths in detail. Advanced control circuits, including drum level, economiser water bypass, attemperator and steam bypass controllers are also included. The parabolic trough power plant is modelled using Advanced Process Simulation Software (APROS). The comparison between the simulation results and measured data is documented, showing a reliable prediction of the real behaviour of the investigated solar power plant. The validated model offers a possibility for accurate simulation of further operation processes of the real plant.     

基于AVR单片机的槽式太阳能集热器追光控制系统设计

使用AVR单片机和光敏电阻设计了一种应用于槽式太阳能聚光器的追光控制系统。把4个光敏电阻放置在遮光板的两边,遮光板形成的阴影使得光敏电阻阻值随着太阳入射角而变化。设计电路把光敏电阻的阻值转换成电压,输入到AVR单片机内部的ADC进行数据采集。单片机对数据进行处理后,判断出太阳的位置,控制直流电机驱动聚光槽转动追光。经实验证明,该设计能够满足槽式聚光系统的追光要求。     

Cascade control of a distributed collector solar field

This paper reports experimental results on the cascade control of a distributed collector solar field. The control problem consists of keeping constant the field outlet oil temperature by acting on the circulating oil flow used for heat transfer. In the inner loop an adaptive model based predictive controller exploiting the information conveyed by accessible disturbances (radiation changes and inlet oil temperature) is used, while in the outer loop a PID is employed. The need for adaptive control arises from the time varying behaviour of the plant. Due to the generality of the methods employed, the experience reported is relevant to a wide class of industrial processes.     

太阳能热发电蓄热系统的混杂建模与仿真

蓄热系统是太阳能热发电站中保证电站可靠性和经济性的重要组成部分,其工作状况直接影响到太阳能热发电站的正常运行。本文针对单罐式蓄热系统,分析了系统在蓄热和放热模式下的动态数学模型,在此基础上,提出了蓄热系统的混杂动态系统模型。该模型将蓄热和放热模式统一在一个框架下,能够对蓄热系统的各种操作模式及其循环交替过程进行动态模拟。混杂模型采用MATLAB软件进行仿真,仿真结果:表明了模型的有效性。     

Robust model predictive control for a nanofluid based solar thermal power plant

Among the several technologies for solar energy recovery, parabolic solar collectors have emerged as one of the most promising due to their performance, which can be enhanced if nanofluids are employed as heat transfer fluids instead of the traditional alternatives. The inherent time-dependent behavior of solar radiation profiles forces the solar thermal plants to be operated aided with controllers able to reject these strong disturbances. While traditional controllers can be employed for this aim, more advanced techniques such as Model Predictive Control are suggested since this optimal-control based method can be tuned to minimize operating costs, among some other features. The main objective of this work is to implement an MPC controller to a nanofluid-based solar thermal power plant in order to evaluate its performance to reject disturbances on the solar radiation profile in an efficient manner. An off-line nonlinear programming optimization was deployed so we could compare the response of the on-line MPC implementation on a strict enough basis. Furthermore, the performance of MPC controllers is affected by how well does the modeling of the system is able to stick to reality, thus, it is important to test if the controller is robust enough to deal with uncertainty that might be introduced as modeling errors. Results indicate that MPC controllers are suitable for their implementation on these kinds of power plants since they steer the system to achieve desired conditions by smoothly manipulating the decision variable, even in the scenarios where a substantial cascade-effect modeling error was imposed in the parameters of the nanofluid.     

Feedback linearization control for a distributed solar collector field

This article describes the application of a feedback linearization technique for control of a distributed solar collector field using the energy from solar radiation to heat a fluid. The control target is to track an outlet temperature reference by manipulating the fluid flow rate through the solar field, while attenuating the effect of disturbances (mainly radiation and inlet temperature). The proposed control scheme is very easy to implement, as it uses a numerical approximation of the transport delay and a modification of the classical control scheme to improve startup in such a way that results compared with other control structures under similar conditions are improved while preserving short commissioning times. Experiments in the real plant are also described, demonstrating how operation can be started up efficiently.     

槽式太阳能热发电跟踪控制系统的研究

太阳能取之不尽、用之不竭,槽式太阳热发电是目前国际上发电规模最大,且已实现商业化的、较为理想的太阳热发电技术;研究设计了一种新型的对太阳实现自动跟踪控制系统,该系统采用四象限探测器作为太阳传感器的核心部件,以单片机作为跟踪控制系统的主控制器,通过数据采集、计算和比较,并且利用时钟芯片对系统进行反馈修正,驱动步进电机,实现了对太阳的自动跟踪,并完成对该跟踪系统的自动控制;该方法成本低廉,运行可靠准确,将有利于提高太阳能槽式聚光发电系统的效率,并为下一步工程化奠定理论试验基础。     

太阳能电池板发电效率的实验研究

为了更好的利用太阳能资源,针对南京地区太阳能发电的应用问题,设计并实验分析了太阳能电池板在不同波长光照下发电效率的规律,并进行了不同照射角度下发电效率的实验研究.文中设计了太阳能电池板发电效率的测试方案,采用滤光片分别进行了四种波长太阳光线的获取;针对太阳能电池板的组合排列,分别设计了五种组合方式,并对每一种组合方式进行了实验研究.实验结果表明,在南京地区的天气中,中午12到14点太阳能发电效率最高;在波长方面,大于600nm的光线的发电效率最大;在实用性方面,四个太阳能电池板并联方式提供的电流最强,四个串联方式提供的电压能量最大.研究结果能为更好地利用太阳资源能提供良好的借鉴.     

太阳能补给下无线传感器网络分簇路由算法*

分析太阳光照特点,设计了太阳能补给模型,并在此模型下提出了一种自适应的分簇路由算法ACSP,定义了网络有三种状态:耗能期、储能期、稳定期,并适应各个时期设计不同的簇首选择和路由选择机制。理论和实验表明,ACSP可自适应网络中能量变化,充分利用补给能量,并且具有较好的能耗均衡性。     

Interactive smart battery storage for a PV and wind hybrid energy management control based on conservative power theory

This paper presents interactive smart battery-based storage (BBS) for wind generator (WG) and photovoltaic (PV) systems. The BBS is composed of an asymmetric cascaded H-bridge multilevel inverter (ACMI) with staircase modulation. The structure is parallel to the WG and PV systems, allowing the ACMI to have a reduction in power losses compared to the usual solution for storage connected at the DC-link of the converter for WG or PV systems. Moreover, the BBS is embedded with a decision algorithm running real-time energy costs, plus a battery state-of-charge manager and power quality capabilities, making the described system in this paper very interactive, smart and multifunctional. The paper describes how BBS interacts with the WG and PV and how its performance is improved. Experimental results are presented showing the efficacy of this BBS for renewable energy applications.     

基于TL431的太阳能LED路灯控制器设计

设计了一种采用低成本TL431等电子器件的新型控制器,具有过充电、过放电保护、LED准恒流控制等功能,并可根据亮度自动启动和关闭LED路灯。实验表明:该控制器不仅能够满足LED路灯的控制要求,而且运行可靠、成本低廉、维修方便,具有极高的推广价值。     

Comparable investigation of backtracking search algorithm in automatic generation control for two area reheat interconnected thermal power system

This paper concentrates on the validation of metaheuristic algorithms like backtracking search optimization algorithm (BSA) and fruit fly optimization algorithm (FFA) for tuning a optimal PID controller for automatic generation control. For this purpose, a two area reheat interconnected thermal system with nonlinearities like generator rate constant (GRC), deadband and time delay are considered. The proposed work is implemented using MATLAB Simulink for various load conditions with objective functions for metaheuristic algorithms capturing signals from various positions of proposed model. The results obtained using two algorithms are compared and explored.     

异步电机功率因数自动控制的研究

本文给出了一种异步电机功率因数自动控制的实施方案,并在不同负载下进行了实验,实验结果表明,该方法在轻空载时具有明显的节能效果。     

基于GSM技术的太阳能集热监控系统设计

太阳能集热系统具有出色的节能减排效果,逐步应用于学校、宾馆以及厂矿企业等热水需求较大的场合.文中介绍基于FX(2N)的太阳能集热监控系统总体方案、硬件及软件设计,着重介绍GSM技术在太阳能集热系统远程监控中的应用,太阳能集热系统发生故障时,向管理人员发送报警短信,同时,管理人员可通过手机短信对太阳能集热系统进行远程控制及参数查询.     

A new algorithm based on spline in tension approximation for 1D quasi-linear parabolic equations on a variable mesh

In this paper, we propose a new two-level implicit method of order two in time and four in space directions, based on spline in tension approximation for the numerical solution of one space dimensional quasi-linear parabolic partial differential equation on a uniform mesh. We have discussed the derivation of the proposed method in detail and have also discussed the stability analysis for a model problem. We have extended the method to non-uniform mesh. Numerical results are given to illustrate the usefulness of the proposed methods.     

一种基于功率控制的无线传感器网络MAC协议

提出了一种基于功率控制的无线传感器网络MAC协议,根据节点接收阈值,计算出节点发送最优功率,在根本上减小发送功率从而节省节点能量。为了减少节点间的碰撞,引入了自适应调整竞争窗口和快速退避机制,减少节点空闲时间,从而进一步减少节点耗能。仿真结果显示在能量和吞吐量上都有显著提高。     

基于模型预测控制的数据中心节能调度算法

如今日益增长的数据中心能耗,特别是冷却系统能耗已日益受到重视,降低系统能耗能够减少数据中心碳排放.提出了一种基于模型预测控制（model prediction control,简称MPC）的节能调度策略,该策略可以有效地减小数据中心冷却能耗.该方法采用动态电压频率调节技术来调整计算节点频率,从而减少节点间的热循环;所有节点的峰值温度可被保持在温度阈值下,在任务的执行中稳态误差较小.该方法可以通过动态频率调节来抑制由于负载类型变化造成的模型不确定性带来的内部扰动,分析结果表明,基于模型预测的温控算法系统开销较小,具有良好的可扩展性.基于该算法设计的控制器能够有效地降低输入温度,提高数据中心能耗效率.通过在实际数据中心内运行的模拟网上书店,该方法与安全最小热传递算法和传统反馈温控算法这两种经典方法相比,无论是在正常条件下还是在扰动存在的情况下都能取得较好的温度抑制效果,系统性能如吞吐率也达到最大.在相同的负载条件下,该方法能够获得最小的输入峰值温度和最小的冷却能耗.