MICROCONTROLLER BASED HYBRID SOLAR TRACKING SYSTEM

Transcription

1 MICROCONTROLLER BASED HYBRID SOLAR TRACKING SYSTEM Hepsiba D 1, L D Vijay Anand 2 1 Department of Electrical Technology, Karunya University 2 Department of Electrical Technology, Karunya University Abstract - In recent years, Solar panel has been used increasingly to convert solar energy to electrical energy. In order to maximize the electrical energy, the solar panels have to be positioned perpendicular to the sun to convert solar energy to electrical energy. This solar tracking system consists of Light Dependent Resistor (LDRs), microcontroller, gear motor system and a solar panel. The tracking is done based on two parameters: maximum intensity of sunlight and maximum power generated with the help of data obtained from the sensors, using ATMEGA2560 microcontroller. Key Words - LDR, Solar Panel, Current Sensor, ATMEGA2560 I. INTRODUCTION The regeneration energy also called green energy, has gained much attention in the recent days. The green energy can be recycled, such as solar energy, water power, wind power, biomass energy, temperature difference of sea, sea waves, morning and evening tides, etc. Among them, solar energy is the most powerful resource that can be used to generate power. So far the efficiency of generating power from solar energy is relatively low; therefore it is very important to increase its efficiency to generate power. Renewable energy is a kind of energy that comes from resources which are continuously replenished such as sunlight, wind, rain, tides, wave sand geothermal heat. The solar energy can be directly converted into electrical energy by means of photovoltaic energy, i.e. conversion of light into electricity. Generation of electromotive force due to absorption ionizing radiation is known as photovoltaic effect. To convert sunlight to electricity the solar cells are used as energy conversion devices. Photovoltaic energy conversion is one of the most popular non conventional energy sources. The photovoltaic cell gives an existing potential for capturing solar energy that will provide clean, versatile, renewable energy. This simple device has no moving parts, negligible maintenance cost, produces no pollution and has a life time equal to that of a conventional fossil fuel. In this paper, a solar tracking system is setup to track the direction of the sun for production of electric power. Power is calculated according to the output from the panel and the current sensor. II. SYSTEM OVERVIEW The solar panel with the LDR on both sides is used to capture the sunlight [1]. As the output of the LDR is resistance, it is converted into voltage using the voltage divider. This voltage is given as input to the microcontroller, which is converted into current inside the controller using programming. The voltage from the panel is multiplied with the obtained current to calculate the power. The solar panel is tilted to the position which has the maximum voltage and power. DOI : /IJRTER P9AM 325

2 Figure-1 Block diagram of solar tracking system The hardware set up is shown in Figure 2. The solar panel is placed on a stand and two LDRs are placed on two sides of the solar panel [2]. The output of the LDR which is in the form of resistance is converted into voltage using a voltage divider. Depending on the highest voltage from the voltage divider, the microcontroller gives command to the motor to rotate in Clockwise or Anticlockwise direction [5]. Power is calculated according to the output from the panel and the current sensor. The power obtained is given to the ATMEGA2560. Depending on the values of intensity and power, the panel tilts accordingly to receive more of solar energy. Thus the position of the sun is tracked. Figure-2 Hardware All Rights Reserved 326

3 III. MATERIALS A. LDR LDR is a resistor whose resistance decreases with increasing incident light intensity, or in other words, it exhibits photoconductivity. Two LDRs of the same resistance values are used. A sensor holder is designed to place the sensor in order to make it more sensitive. The sensors are placed in the two opposite ends of the panel. The resistance changes depending upon the intensity of light. B. CURRENT SENSOR The voltage from the solar panel is given as the input to the current sensor. The supply voltage for the current sensor is 0-14V. The output voltage from the Vout pin is given to the ATMEGA2560 for calculating power. The current sensor can sense up to 0-2A. C. L298 DUAL FULL BRIDGE DRIVER CIRCUIT It is a high voltage, high current dual full-bridge driver designed to accept standard TTL logic levels and drive inductive loads such as relays, solenoids, DC and stepper motors. Two enable inputs are provided to enable or disable the device independently of the input signals. [6] D. ATMEGA2560 MICROCONTROLLER The microcontroller used is high-performance, low-power Atmel 8-bit AVR RISC-based microcontroller which has high performance and works with low power consumption. The operating voltage of the device is between volts. IV. CURRENT SENSOR CALIBRATION The power tracking system is developed using a current sensor. The output of the current sensor is voltage. This voltage is given as input to the microcontroller, which is converted into current inside the controller using programming. The voltage from the panel is multiplied with the obtained current to calculate the power. The calibration of the current sensor is done, in order to fix the supply voltage which is to be given to the current sensor so that the output voltage remains below 5v. The calibrated values are tabulated below: Vout (Volts) Table-1 Calibration of current sensor CURRENT RESISTANCE (amps) (Ω) All Rights Reserved 327

4 A graph is plotted between the obtained voltage and current keeping voltage in the x-axis and current in the y-axis. Figure-3 Current sensor VI graph V. TEST RESULTS The solar panel has been tested under sunlight for various timings such as: 10:00 am, 11:00 am, 12:00 pm, pm, 03:00 pm and 04:00 pm. Table 2 shows the resistance, current, voltage, power values tested at pm. The voltage and current readings are obtained by changing the resistance. The PV graph shown in figure-4 is plotted for the various timings as mentioned above [3]. Table -2 Solar panel tested readings (12 Noon) VOLTAGE RESISTANCE (kω) CURRENT (amp) (volt) POWER (watts) All Rights Reserved 328

5 Figure-4 PV graph for various timings The objective of testing the panel for various timings and plotting the PV graph is to analyze the time at which the peak value of the power is obtained. Using the power and voltage values tabulated in the above table the PV graph is plotted [4]. Voltage is taken in x-axis and power is taken in y-axis respectively. The testing which is done concludes that the peak value of the power is obtained at 12:00 pm. VII. CONCLUSION The hybrid solar tracking system is designed and implemented using ATMEGA2560 microcontroller. This system can track the sun light automatically. Thus, the efficiency of solar energy generation can be increased. The solar panel has achieved the capability of tracking the sun rays for maximum intensity as well as maximum power using microcontroller programming and the motor was made to run with a motor driver circuit as intermediary. The hybrid solar power tracking system is highly beneficial to the solar power generation. REFERENCES 1. Bhupendra Gupta, Neha Sonkar, Brahman Singh Bhalavi, Pankaj J Edla, Design, Construction and Effective Analysis of Hybrid Solar Tracking System for Amorphous and Crystalline Solar cells, American journal of Engineering Research, Vol. 2, Issue-10,pp Ashraf Balabel, Ahmad A Mahfouz, Farhan A Salem, Design and Performance of Solar Tracking Photo-Voltaic System, International Journal of Control, Automation and Systems, Vol 1 No.2, pp 49-55, Reshmi Banerjee, Solar Tracking System, International Journal of Scientific and Research Publications, Volume 5, Issue 3, March Narendrasinh.J.Parmar, Ankit.N.Parmar, Vinod.S.Gautam, Passive Solar Tracking System, International Journal of Emerging Technology and Advanced Engineering, Vol 5, Issue 1, January Mostefa Ghassoul, Design of an Automatic Solar Tracking System to Maximize Energy Extraction, Vol 3, Issue 5, May All Rights Reserved 329