International Journal of Computer Applications (0975 – 8887) Volume *– No.*, ___________ 2015
Microcontroller based dual axis solar tracking system Badri Narayan Mohapatra
Rashmita Kumari Mohapatra
Research scholar CUTM, INDIA
Asst.Prof.(EXTC), TCET, INDIA
[email protected]
[email protected]
ABSTRACT Energy crisis is the most important issue in today’s world. Finding energy sources to meet the expectations of the world’s growing demand is one of society’s important challenges for the next half-century. The contest in converting sunlight to electricity via photovoltaic solar cells is impressively reducing $/watt of delivered solar electricity. In this context the sun trackers are such devices for efficiency improvement. Solar tracking system is the most suitable technology to improve the quality of the efficiency of the solar cells by tracking the sun. Azimuth-elevation and tilt-roll tracking mechanism are among the most commonly used suntracking methods for aiming the solar collector towards the sun at all times. A microcontroller based design methodology dual axis solar tracker is presented in this paper.
microcontroller utilizes information about latitude , longitude as well as time of date and day to control the actuator and track the movement of sun without sensors.
Keywords Solar panel, solar tracking, microcontroller
1. INTRODUCTION S. Shanmugam et al. had given the tracking of the sun for solar paraboloidal dish concentrators in 2005[1]. Rong-Jong Wai et al. had given grid connected photovoltaic (PV) generation system with an adaptive step-perturbation (ASP) method and an active sun tracking scheme in 2006.[2]. Cemil Sungur had given the electromechanical control system of a photovoltaic (PV) panel tracking the sun on the axis it moved along according to its azimuth angle in 2007.[3]. The elevation angle of the sun be in the same place almost invariant in a month and varies little (latitude ± 10°) in a year. Therefore, a single axis position control scheme may be enough for the collection of solar energy in some applications (Konar and Mandal, 1991. Yeong-Chau, et al., 2001. Wilamowski and Xiangli, 2002).[4],[5]. Therefore, the average solar energy is not always maximized. Solar tracking systems are essential for many applications such as thermal energy storage systems and solar energy based power generation systems in order to benefit the system performance (Saxena,. and Dutta,. 1990; Koyuncu and Balasubramanian, 1991; Harakawa and Tujimoto, 2001). The change in sun’s position is monitored, and the system always keeps that the plane of the panel is normal to the direction of the sun.,[6]. A few design methodology of solar tracking system has been proposed in recent days [7],[8]. The dual axis solar tracker uses an elevation actuator and an azimuth actuator to alter the azimuth of an attached solar panel fig 1. Microcontroller actually control the actuator controller circuit which control the actuators. The
Fig 1: solar panel
2. BRIEF DESCRIPTION OF DUAL AXIS SOLAR TRACKER The rectangular frame make suitable for receiving a solar panel and the central panel made of amorphous or crystalline silicon are well known for generating electricity directly from sunlight.fig 2 the actuator control circuit is for controlling the direction of current as well as movement of the linear actuators . Control circuit consists 8 resistors along with 4 five-volt DC relay and 4 n-channel BJT. RLY1 and RLY4 can be switching by taking voltage from emitter of BJT circuit. PIC1 & PIC2 voltage applied to back of BJT where as (R1 & Ra) and (R3 & Rb) used for biasing of BJT.(RLY1 &RLY4)and(RLY3 & RLY2) are series with each other & it controls the linear actuator. RLY3 and RLY2 can be switching by taking voltage from the emitter of BJT circuit. PIC3 and PIC4 voltage are applied to base of BJT where as (R4 & Rd) and (R2 & Rc) used for biasing of bjt.
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International Journal of Computer Applications (0975 – 8887) Volume *– No.*, ___________ 2015
Fig 2: Schematic diagram of an actuator control circuit in a dual axis solar tracker
Fig 4: Block diagram circuit for dual-axis solar tracker
4. PROCESS FOR SOLAR TRACKING The 18f4620 is nothing but PIC microcontroller. BJT turned on and off is controlled by PIC microcontroller. The corresponding relay is turned on only when BJT was turned on and 12 volt will be applied to linear actuator only due to relay closing. For controlling the current direction relays are used like bridge circuit. Actuator extend or retract can be control by the relays.
Initially user first enter the date and time fig-5 . Microcontroller calculate whether date and time is present in between sunrise and sunset. otherwise microcontroller returns to step. Microcontroller proceeds to step only in the daylight hours and calculate the position of the sun based on longitude and latitude, as well as date and time.
3. MOTION OF THE SUN THROUGHOUT THE YEAR 3.1 Importance of Sun position Fig-3 shows the diagrammatic view where it shows the suns motion in summer, winter & in spring. In a year sun takes different path in the sky. latitude only says the exact path of sun.
Fig 3: Diagrammatic view of motion of the sun throughout the year
3.2 Dual-axis solar tracker It (fig 4) shows the block diagram of dual axis solar tracker. Normally solar panel generate solar power which is used for charging 12 volt battery. PIC microcontroller only get power from the voltage regulator which is drived by battery. LCD is attached with microcontroller and for exchanging information with a user a 4 ×4 matrix keypad is used.
Fig 5: flow chart for positioning the solar panel using dual axis solar tracker microcontroller causes the actuator to align when it determine the sun position also arrange with the straight line with the vertical axis of the solar panel . solar panel directly facing the sun due to actuator movement to solar panel and continues to track the sun. The microcontroller proceed back to step if the sun is not effectively set.
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International Journal of Computer Applications (0975 – 8887) Volume *– No.*, ___________ 2015
5. CONCLUSION The design is going to extract maximum power from the sun by tracking it using a dual axis solar panel. This is possible if solar panel is perpendicular to the intensity of light coming from the sun. The paper puts forward a novel approach in improving the output power as well as protection requirements for the circuit from wind and rain.
[3]
Cemil Sungur “Sun –Tracking System with PLC Control for Photo-Voltaic Panels” International Journal of Green Energy, Vol.4, 2007, Page(s): 635–643.
[4]
B. Koyuncu and K. Balasubramanian (1991), “A microprocessor controlled automatic sun tracker’’, IEEE Transactions on Consumer Electronics, vol. 37, no. 4, pp. 913-917
[5]
Konar, A., Mandal,. A. K. 1991. Microprocessor Based Automatic Sun Tracker. IEE Proc.-A. Vol. 138, 4:237-1.
[6]
Solartracking systems are essential for many applications such as thermal energy storage systems and solar energy based power generation systems in order to improve system performance (Saxena,. and Dutta,. 1990; Koyuncu and Balasubramanian, 1991;Harakawa and Tujimoto, 2001).
6. REFERENCES [1]
S.Shanmugam and W.Christraj, “The Tracking of the Sun for Solar Paraboloidal Dish Concentrators”, ASME Transactions, Vol.127, February 2005, Page(s):156-160.
[2]
Rong-Jong Wai, Wen-Hung Wang, Lin and Jun-You, “Grid- Connected Photovoltaic Generation System with Adaptive Step-Perturbation Method and Active Sun Tracking Scheme”, IEEE Transactions on Industrial Electronics, Nov. 2006, Page(s):224 – 228.
[7] Yeong-Chau K., Tsorng-Juu L., Jiann-Fuh, C. 2001. Novel Maximum-Power-Point-Tracking Controller for Photovoltaic Energy Conversion System. Industrial Electronics, IEEE Trans., Vol. 48, 3 : 594-1. [8]
O. Bingol, A. Altinta, and Y. Oner, “Microcontroller based solartracking system and its implementation,” Journal of Engineering Sciences, vol. 12, pp. 243–248, 2006.
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