注入模式下DSG系统反馈线性化串级控制器设计

本文是注入模式下DSG槽式太阳能热发电系统蒸汽温度控制器的研究,在已有太阳能集热器动态方程基础上,先建立太阳能阵列动态方程,然后介绍反馈线性化控制算法,并以PI控制为辅设计反馈线性化串级控制器,再在和利时公司DCS软硬件平台上编程实现并仿真运行,最后对仿真曲线分析得出结论:反馈线性化串级控制器可控制注入模式运行的DSG槽式系统太阳能阵列与太阳能集热器出口蒸汽温度,满足稳定与准确性目标。     

Energy-based control of a distributed solar collector field

Model-based control of the outlet temperature of a distributed solar collector field is studied. An energy-based controller is derived using internal energy as a controlled variable. The controller relies on a distributed parameter nonlinear plant model and includes feedforward from the solar irradiation and inlet temperature. Convergence of the closed loop is proved, and the method is experimentally verified to perform well on a pilot-scale solar power plant.     

一种太阳能集热系统集热量实时预测的混合建模方法

太阳能集热器的集热量受光照度、环境温度、风速等多种因素的影响,其预测模型很难从预测精度和实时性上同时满足用户需求。本文提出一种实时预测太阳能集热系统集热量的混合建模方法。该方法首先从能量守恒出发,根据热管式太阳能集热系统传热机理推导出集热量的理论模型,并把理论模型中的散热系数、透射率、吸收率等经验参数以及采光面积、散热面积等几何参数集总为模型的未知参数,进而提出混合模型的结构。然后,利用TRNSYS仿真软件搭建太阳能集热器模拟仿真系统,对仿真系统不同的运行工况进行仿真实验,获取用于辨识混合模型未知参数的稳态数据。最后,选用粒子群优化算法（PSO）作为模型参数的辨识方法,利用所获得的稳态数据辨识模型的未知参数。模型预测值与仿真实验结果的比较表明,预测模型简单而精确,能够在各种工况下实时地、高精度地预测太阳能集热器的集热量,其平均相对误差可达到2.02%。该模型在太阳能热泵、太阳能热水器等系统的优化控制领域得以广泛应用。     

Optimum design of solar water heating systems

This paper presents an approach to the design of solar water heating systems for optimum performance in different locations. The results of a previously developed queueing model for solar water heating systems evaluation are used to determine the optimum size of the system design parameter. The approach concerns itself in selecting the optimum volume of the system water tank, and its collector area in different locations.     

分体式太阳能热水器控制系统的优化设计

主要完成了分体式太阳能热水器控制系统的软硬件研发及其控制的优化;以ATmega16为控制系统核心,采用DS18B20对集热器进行精确温度控制,以温控模式取代前期光控和低温保护的组合模式,提高了循环效率,简化了控制系统;为保证光热系统的安全可靠,对集热系统进行了高低温保护,并且还对水箱进行智能上水和温度调节控制;同时使用水流传感器检测用户用水信号实现对用水循环泵的控制以提供合适的供水压力;该控制系统通过了调试,实现了预期的设想,具有可行性和实用性。     

Optimal control of a solar collector loop using a distributed-lumped model

This paper considers the optimal control of a solar collector loop described by a bilinear distributed parameter model for the collector fluid temperature and a bilinear lumped parameter model for the storage fluid temperature. The objective is to control the collector fluid velocity so as to maximize the net energy collected over a fixed time period. Necessary conditions for optimality, given by a set of equations whose solution yields the optimal control, are derived. It is shown that the optimal control is an open-loop, bang-bang control which depends on two terms: a measurable quantity which depends on the state of the collector fluid, and a quantity which depends on a future knowledge of the weather data. It is also shown that for the case in which only two switches occur during the period of operation, the optimal control depends only on the temperature difference across the collector. Thus, one can construct a feedback on/off controller for the system provided that it is known a priori that only two switches will occur during the time interval under consideration.     

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.     

两维程控太阳跟踪器控制系统的研制

通过对太阳运行轨迹理论的分析和研究,确定了太阳跟踪器的运动数学模型,并就其不同的天文算法公式进行了比较和选择,以保证系统的跟踪精度。在此基础上针对太阳跟踪器的控制原理,提出了系统的技术方案,详细阐述了控制系统的软件平台和硬件电路的设计。试验结果表明:两维程控太阳跟踪器的性能指标完全满足应用要求,运行稳定可靠,能适应各种复杂环境条件,这将在气象观测、高精度太阳跟踪测量以及太阳能源利用等领域有重要和广泛的应用。     

Time scaling internal state predictive control of a solar plant

The control of a distributed collector solar field is addressed in this work, exploiting the plant's transport characteristic. The plant is modeled by a hyperbolic type partial differential equation (PDE) where the transport speed is the manipulated flow, i.e. the controller output. The model has an external distributed source, which is the solar radiation captured along the collector, approximated to depend only of time. From the solution of the PDE, a linear discrete state space model is obtained by using time-scaling and the redefinition of the control input. This method allows overcoming the dependency of the time constants with the operating point. A model-based predictive adaptive controller is derived with the internal temperature distribution estimated with a state observer. Experimental results at the solar power plant are presented, illustrating the advantages of the approach under consideration.     

Experimental investigation on a parabolic trough solar collector for thermal power generation

Developing solar thermal power technology in an effective manner is a great challenge in China.In this paper an experiment platform of a parabolic trough solar collector system(PTCS) was developed for thermal power generation,and the performance of the PTCS was experimentally investigated with synthetic oil as the circulate heat transfer fluid(HTF).The solar collector's efficiency with the variation of the solar flux and the flow rate of the HTF was identified.The collector efficiency of the PTCS can be in ...     

基于RS485总线的锂电负极材料石墨化炉数据采集器

重点介绍了一种应用于锂电负极材料石墨化炉多路温度实时采集器的硬件和软件设计。此采集器以Freescale MC9S08DZ60单片机为核心,完成多路数据采集,软硬件结合进行数据处理,带有RS485总线接口,采用Modbus/RTU协议与上位机进行通信。运行结果表明所设计的温度采集器能够满足生产需要,且结构简单,易于和其他设备接口,具有很好的实用价值。     

竖井变形自动综合测量仪

介绍了竖井变形自动综合测量仪的设计原理和技术方案,给出了数据采集器硬件电路设计及其框图、计算机程序设计流程图。     

基于3G的能耗数据采集器设计

针对大型公共建筑实时监控能耗的需求,借助3G网络传输的优势,提出了一种基于3G的能耗数据采集器的设计方案。该方案使用STM32为主控制器,根据Modbus通信规约通过RS485方式实现对智能电表的能耗数据采集,再将数据通过3G无线网络远传至服务器。重点设计了采集器的硬件电路,数据采集与传输驱动程序。经实验室测试,该采集器能实时、准确地采集数据并传送至服务器,性能稳定可靠,能够满足能耗监测系统的需求。     

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。     

太阳能跟踪控制器硬件设计

为了实现对太阳能全面而且有效率的使用,常用的方法是跟踪太阳的方位角,从而增加太阳能吸收的输出功率。这篇文章描述了太阳能跟踪控制器的控制思想,以及系统硬件组成控制算法。通过这种简易跟踪控制器的设计以及双轴太阳能跟踪控制器的可靠控制,可以实现太阳能利用率的提高。而且,通过手电筒模拟太阳光源,可以证明的是这个系统可以可靠的工作。整个系统主要由硬件和软件组成,硬件部分包括：单片机89C54RD＋外围电路,8位模数转换电路,光电检测电路,EEPROM电路,LED信号显示电路,供电电路,串行通讯电路等。此外,软件中单片机的控制和主监控程序是基于KeiluVision2．0平台编写的。最后,两个电动的舵机拖动双轴机械装置对太阳光源进行方位角和高度角两个方向的跟踪。     

太阳集热器闭式循环系统流量控制

首先介绍太阳集热器热性能测试系统对流量控制的基本要求,然后给出一种闭式循环系统中小流量的控制方法,解决闭式循环系统中流动介质温度大幅度升高时产生汽泡的问题,提出一种精确测量流量的办法。实践表明,这种流量控制系统具有响应速度快、超调量小、稳态精度高的特点。     

Repetitive control of tubular heat exchangers

Effective operation of heat exchangers involves optimum control of the fluid outlet temperature. Several ideas have been proposed in the literature to cope with intrinsic resonance dynamics aimed at widening the bandwidth of the closed-loop system to achieve fast, well-damped responses in controlling the outlet fluid temperature by means of the steam temperature. This is also the main purpose of this article, in which the use of a repetitive control scheme is proposed to take resonance dynamics into account when residence time is variable, as in this case the control variable is the fluid flow rate and not the steam temperature. The scheme is based on a model of the tubular heat exchanger dynamics in which the explicit terms of resonance are cancelled out by the controller. Simulation results are provided both for a typical tubular heat exchanger and for a special sort of heat exchanger, the distributed collector field of a solar power plant.     

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.     

Adaptive UKF-based model predictive control of a Fresnel collector field

One of the ways to improve the efficiency of solar energy plants is by using advanced control and optimization algorithms. In particular, model predictive control strategies have been applied successfully in their control.The control objective of this kind of plant is to regulate the solar field outlet temperature around a desired set-point. Due to the highly nonlinear dynamics of these plants, a simple linear controller with fixed parameters is not able to cope with the changing dynamics and the multiple disturbance sources affecting the field.In this paper, an adaptative model predictive control strategy is designed for a Fresnel collector field belonging to the solar cooling plant installed at the Escuela Superior de Ingenieros in Sevilla. The controller changes the linear model used to predict the future evolution of the system with respect to the operating point.Since only the inlet and outlet temperatures of the heat transfer fluid are measurable, the intermediate temperatures have to be estimated. An unscented Kalman filter is used as a state estimator. It estimates metal-fluid temperature profiles and effective solar radiation.Simulation results are provided comparing the proposed strategy with a PID + feedforward series controller showing better performance. The controller is also compared to a gain scheduling generalized predictive controller (GS-GPC) which has previously been tested at the actual plant with a very good performance. The proposed strategy outperforms these two strategies.Furthermore, two real tests are presented. These tests show that the proposed controller achieves adequate set-point tracking in spite of strong disturbances.