IMPROVING THE EFFICIENCY OF A PHOTOVOLTAIC SYSTEM BY INCORPORATING TRACKING SYSTEM AND MPPT: A REVIEW <s> By the use of a sensing system <s> This paper presents a Sun-tracking design, whereby the movement of a photo-voltaic module was controlled to follow the Sun's radiation using a programmable logic-controller (PLC) unit. All electronic circuits and the necessary software have been designed and developed to perform the technical tasks. A PLC unit was employed to control and monitor the mechanical movement of the PV module and to collect and store data related to the Sun's radiation. It is found that the daily output power of the PV was increased by more than 20% in comparison with that of a fixed module. The PV-tracking system can be employed as a stand-alone device and it could be connected to a personal computer through the RS232 serial port to monitor the whole process on a computer screen. <s> BIB001 </s> IMPROVING THE EFFICIENCY OF A PHOTOVOLTAIC SYSTEM BY INCORPORATING TRACKING SYSTEM AND MPPT: A REVIEW <s> By the use of a sensing system <s> In this paper, a new micro-controller based solar-tracking system is proposed, implemented and tested. Thescheme presented here can be operated as independent of the geographical location of the site of setting up. Thesystem checks the position of the sun and controls the movement of a solar panel so that radiation of the suncomes normally to the surface of the solar panel. The developed-tracking system tracks the sun both in theazimuth as well as in the elevation plane. PC based system monitoring facility is also included in the design. <s> BIB002
The use of a sensing system for the detection of the position of maximum irradiation involves the use of light detecting sensors and a control unit. The light detecting sensor generally used is the light detecting resistor BIB002 BIB001 . Two light detecting resistors are used per axis. Al-Mohamad BIB001 made use of two LDR for sensing along the azimuth axis. A Programmable Logic Controller (PLC) unit was used as the control unit to operate the drive system of the tracker. Bingol, Altintas and Oner BIB002 designed a dual-axis tracker using four LDR and a microcontroller. Though the use of a sensing unit adds to the cost of the tracker, it is more preferred compared with the system involving solar equations. The solar radiation is not constant throughout the year and varies with altitude and location. These variations are not accommodated in the equations.