Comprehensive Utilization And Optimal Control Of Photovoltaic/Thermal

The thesis is focused on studying a kind of photovoltaic thermal platform(PV/T)with the purpose of achieving the comprehensive utilization of photovoltaic thermal and its optimal control.The major method adopted is to convert the solar collector to be a solar panels.Utilizing flowing water to reduce the comparative high temperature of the solar panels,it can help to improve the efficiency of solar photovoltaic panels and prevent the photovoltaic panels from aging so as to prolong the lifespan of photovoltaic panels;On the other hand,the waste heat which are generated by the photovoltaic panels can be collected and used for heating the domestic water,finally,combining with the heat pump,it can provide domestic hot water and realize the comprehensive utilization of photovoltaic thermal.In addition,the thesis also takes the dynamic optimization control of this system into account in the process of collecting heat,in order to carry out the optimal control with the purpose of optimizing the solar efficiency.First of all,in order to study the comprehensive utilization of photovoltaic thermal,we build a photovoltaic thermal platform which are mainly a combination of solar collector,water pumps and heat pump.Aiming at studying the comprehensive utilization of photovoltaic thermal properties,we considered about various parameters that might interfere the operation of photovoltaic thermal system in the process of setting up the platform.What's more,the photovoltaic thermal monitoring system based on LabVIEW is accomplished by using corresponding hardware collecting platform and Lab VIEW software program.In the thesis,the photovoltaic thermal monitoring system is the vital foundation for studying the comprehensive utilization of photovoltaic thermal.Through the monitoring system,various relevant parameters such as light,temperature,frequency and other parameters that may affect the system can be detected.The content of the thesis is focused on the basis of monitoring system measurement.By a large number of data measurement and finding out the relation among all kinds of parameter,then using regression analysis to find out the inner relation of the variables,after dealing the photovoltaic thermal system with modularity,the thesis try to find appropriate variables and making modeling,then setting up a objective function aims at making the system obtain optimized solar powers,finally,using MATLAB software to compile a optimized procedure to reach the goal of optimal control.In this paper,three optimization algorithms are discussed and compared:golden section method,the parabolic interpolation method and the fininbnd function which are based on the above two methods.Finally,the thesis adopt the fminbnd function to realize the algorithm of optimal control.By embedding the MATLAB program into the LabVIEW program,the hybrid program realize the dynamically optimal control of Photovoltaic thermal.Finally,by observing the range of objective function,we can roughly estimate that the economic efficiency brought by the comprehensive utilization of photovoltaic thermal and its optimal control is considerable.