Control of a Solar Energy Systems

8th IFAC Symposium on Advanced Control of Chemical ProcessesThe International Federation of Automatic Control Singapore, July 10-13This work deals with the main control problems found in solar power systems and the solutions proposed in literature. The paper first describes the main solar power technologies, its development status and then describes the main challenges encountered when controlling solar power systems. While in other power generating processes, the main source of energy can be manipulated, in solar energy systems, the main source of power which is solar radiation cannot be manipulated and furthermore it changes in a seasonal and on a daily base acting as a disturbance when considering it from a control point of view. Solar plants have all the characteristics needed for using industrial electronics and advanced control strategies able to cope with changing dynamics, nonlinearities and uncertainties.Ministerio de Ciencia e Innovación PI2008-05818Ministerio de Ciencia e Innovación DPI2010-21589-C05-01/04Junta de Andalucía P07-TEP-0272

Modelling Free Response of a Solar Plant for Predictive Control

IFAC System Identification, Kitakyushu, Fukuoka,Japan,1997This paper deals with the identification of a nonlinear plant by means of a neural network (NN) modelling approximation. The problem of neural identification is tackled using a static NN in a NARX configuration. A method is proposed to obtain the number of past values needed to feed the network. The on-line adaptation of the model and other issues are discussed. In order to show the benefits that can be achieved with the proposed methods, the NN model is used within a Model Predictive Control (MPC) framework. The MPC scheme uses the prediction of the output of the system calculated as the sum of the free response (obtained using the nonlinear NN model) and the forced response (obtained linearizing around the current operating point) to optimize a performance index. The control scheme has been applied and tested in a solar power plant

Control of Solar Power Systems: a survey

9th International Symposium on Dynamics and Controlof Process Systems (DYCOPS 2010)Leuven, Belgium, July 5-7, 20109This paper deals with the main control problems found in solar power systems and the solutions proposed in literature. The paper first describes the main solar power technologies, its development status and then describes the main challenges encountered when controlling solar power systems.Ministerio de Ciencia y Tecnología DPI2008-05818Ministerio de Ciencia y Tecnología DPI2007-66718-C04-04Junta de Andalucía P07-TEP-0272

Adaptive control of a solar furnace for material testing

IFAC Adaptive Systems in Control and Signal Processing. Glasgow. Scotland. UK. 26/08/1998This paper presents an adaptive control system for controlling the temperature of a solar furnace, which is a high solar concentrating facility made up of heliostats tracking the sun and reflecting solar radiation onto a static parabolic concentrating system at the focal spot of which a high percentage of the solar energy collected by the collector system is concentrated in a small area. A large attenuator (shutter) placed between the collector system and the concentrator serves to control the amount of solar energy used for heating the samples placed at the focal spot. The paper shows the results obtained in the application of adaptive PI controllers to a solar furnace, incorporating feedforward action, anti-windup and slew rate constraint handling mechanisms

A Robust Adaptive Dead-Time Compensator with Application to A Solar Collector Field

This paper describes an easy-to-use PI controller with dead-time compensation that presents robust behaviour and can be applied to plants with variable dead-time. The formulation is based on an adaptive Smith predictor structure plus the addition of a filter acting on the error between the output and its prediction in order to improve robustness. The implementation of the control law is straightforward, and the filter needs no adjustment, since it is directly related to the plant dead-time. An application to an experimentally validated nonlinear model of a solar plant shows that this controller can improve the performance of classical PID controllers without the need of complex calculations.Ministerio de Ciencia y Tecnología TAP95-37

Control de plantas solares con generación automática de consignas

En este trabajo se muestran los resultados de operación de un campo de colectores solares del tipo cilindro parabólico de forma automática con una estructura de control por adelanto en paralelo con un controlador tipo I-PD que incorpora como principal novedad un sistema de generación automática de consignas. El objetivo de control para este sistema es mantener la temperatura del fluido a la salida del campo a un valor establecido, compensando las perturbaciones a las que está sometida la planta con dinámica fuertemente no lineal.Ministerio de Ciencia y Tecnología DPI2001-2380-C02Ministerio de Ciencia y Tecnología DPI2002-04375-C0

Estructura de regulación con generación automática de consignas y control por adelanto para un campo de colectores solares

En este artículo se muestran los resultados de operación de un Campo de Colectores Solares del tipo Cilindro Parabólico de forma automática por una estructura de control por adelanto en paralelo con un controlador tipo I-PD con generación automática de consignas. El objetivo de control para este sistema es mantener la temperatura de salida del fluido que circula por las tuberías del campo a un valor establecido, a pesar de las perturbaciones a las que está sometida la planta. Dichas perturbaciones se producen en la temperatura del fluido que entra al campo, procedente de un tanque de almacenamiento térmico, en la temperatura ambiente o en la radiación solar. Esta última constituye la fuente primaria de energía del sistema. Las dificultades para operar la planta son debidas a las perturbaciones citadas anteriormente y que no son manipulables, a las no linealidades y a su dinámica compleja. Para ello se ha diseñado una estructura de control que mantiene la temperatura de salida de los lazos a un nivel que se determina automáticamente mediante un generador de consignas que tiene en cuenta las condiciones en las que se encuentra la planta (radiación, temperatura a la entrada y temperatura ambiente) y ciertos parámetros necesarios para la operación segura de la planta. La variable manipulada es la velocidad a la que una bomba de alimentación envía al campo solar el aceite procedente del tanque de almacenamiento. La energía térmica almacenada se utiliza para producir agua desalinizada o energía eléctrica.Ministerio de Ciencia y Tecnología DPI2001- 2380-C02Ministerio de Ciencia y Tecnología DPI2002-04375-C0