Optimal design of the solar tracker used for a photovoltaic string

Abstract

This paper approaches the optimal design of the mono-axial tracking system used for a string of photovoltaic (PV) modules. The tracking mechanism is designed in a CAD (Computer Aided Design) environment (SolidWorks), the solid model being then transferred in the dynamic analysis and optimization environment (adams/View). The control system is designed with adams/Controls and matlab/Simulink, in mechatronic concept, by integrating the mechanical device and the control system at the virtual prototype level. The control method is based on a single-open-loop model with PID (Proportional-Integral-Derivative) controller, having as input the daily angle of the PV string. The output from the control system (i.e., the input in the mechanical device model) is the motor torque developed by the rotary actuator that drives the system. The tracking program has been developed by using an empirical model of the solar irradiation, obtaining the optimal angular field for the daily motion, the number of motion steps, and the actuating time. The optimization purpose is to minimize the tracking error, the design objective's value being the root mean square during simulation. The specific parameters of the PID controller are used as design variables in the optimization process. The investigation strategy is based on a design of experiments technique, obtaining the appropriate regression function. Finally, the physical prototype is developed and tested in real environment, the experimental results being used to validate the virtual prototyping-based simulation.

Changes of Photovoltaic Performance as a Function of Positioning Relative to the Focus Points of a Concentrator PV Module: Case Study

“…Several sources suggest that dual-axis tracking solutions are more efficient and can also be cost-effective if bigger systems are implemented. Nevertheless, the implementation of solar tracking devices is only justified if the amount of electrical energy produced compensates for the costs of the equipment, the maintenance and the energy consumed by the moving parts [23,38,[40][41][42].…”

A Real-Time Optimization Approach to the Efficiency of a Photovoltaic System by a Hybrid Tracking Technique using LabVIEW

“…The correction of the error related to the change of the position and the distance of the sun with respect to the photovoltaic module making it possible to keep the latter always perpendicular to the solar irradiations, obliges the use of a correction system with two axes, the first concerns the variation day-night, the second concerns the variation of the seasons (the point of sunrise compared to the zenith) (Alexandru and Tatu, 2013;Radu and Mihai, 2014).…”

A remotely accessible solar tracker system design

“…20 In a different study Alexandru and Tatu developed an optimal design including monoaxial tracking system used for a string of PV modules. 21 In a recent study, Ioniţ a and Alexandru aimed to develop an optimization on pseudo-azimuthal tracker which is not only optimal in the sense of mechanical part but also in the sense of control part of the system. 22 In another study, Gama et al proposed and described a novel single axis sun tracking system that had a moveable absorber which could be adjusted in order to minimize the optical losses caused by the cosine effect in parabolic trough concentrators.…”