Abstract :
In remote areas the sun is a cheap source of electricity because instead of hydraulic generators it uses solar cells to produce electricity. While the output of solar cells depends on the intensity of sunlight and the angle of incidence. It means to get maximum efficiency; the solar panels1 must remain in front of sun during the whole day. But due to rotation of earth those panels can’t maintain their position always in front of sun. This problem results in decrease of their efficiency. Thus to get a constant output, an automated system is required which should be capable to constantly rotate the solar panel.
The
Automatic Sun Tracking System (ASTS) was made as a prototype to solve the
problem, mentioned above. It is completely automatic and keeps the panel in front of sun until that is
visible. The unique feature of this system is that instead of taking the earth as
its reference, it takes the sun as a guiding source. Its active sensors
constantly monitor the sunlight and rotate the panel towards the direction where the intensity of
sunlight is maximum. In case the sun gets invisible e.g. in cloudy weather, then without
tracking the sun the ASTS keeps rotating the solar panel in opposite direction
to the rotation of earth. But its speed of rotation is same as that of earth’s rotation2.
Due to this property when after some time e.g. half an hour when the sun again
gets visible, the solar panel is exactly in front of sun. Moreover the system
can manage the errors and also provides the error messages on the LCD display. In manual mode,
through the software (GUI) at computer, the solar panel can be rotated at any
desired angle.
ASTS can be used for Parabolic Trough tracker, Dishes
tracker, PV (Photovoltaic generator) tracker, Heliostat, Solar Furnace and so
on. Even though the theory of the controller system is similar to all the
applications, there are some differences: the precision requirement for dishes
tracker is more strict than PV tracker, while the Heliostat and solar furnace
need the strictest precision requirement, and more difficult to apply solar
sensor to make a closed-loop control system. So, when design these systems,
selection of motor type, controller type and tracking mode should be different.
Download :