Innovative Solar Energy Solutions with MPPT

CAREER EPISODE 1: The Development of a Solar Maximum Power Tracker

A. INTRODUCTION

CE 1.1

I have provided a description of the project titled “Solar Maximum Power Point Tracker”, which I carried out during the final year while pursuing a bachelor’s degree in Electronics engineering from Karachi Institute of Economics and Technology. I started my work in the stated task on …. and completed it on …….

B. BACKGROUND

CE 1.2

The need and demand of energy has never been so high in our entire existence in the world. With fossil fuel energy being depleted day by day and taking the harm they do to environment into consideration, it is safe to say that they aren’t the ideal choice to carry on as source of energy for the future. In scenario like this, solar energy has proven itself to be very useful. Being a renewable energy, solar energy system harvests the solar energy which instead would have been waste for us. While solar energy system has been the new way to go, it would be very useful to us if we could extract the most out of it through the energy extracting mechanism we design.

To carry out this task, I put forward this project as an idea that can be taken into consideration while designing a solar charging system with high efficiency. I utilized voltage and current sensing mechanism to measure the highest power the solar panel can supply in any particular direction. It is an Arduino based system that uses Arduino Nano which is based on atmega328 microcontroller. With use of servo motor and reliable programming, I have designed a system that measures the power from panel in any direction till it achieves a point with highest power.

CE 1.3

I focused on these objectives while executing the specified work:

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  To modify the existing system with more efficient one.
  
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  To charge the battery using solar panel with maximum efficiency
  
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  To demonstrate a practical renewable energy system with optimal use of resource.
  

CE 1.4

I utilized my knowledge of electronic components and circuits and programming that I learned in my engineering education in this project. I performed circuit design, programming, circuit assembly in the entire duration of my involvement in this project. I studied several journals and papers on the renewable solar energy sources for the deeper insight of the technology that I was dealing with. I held team meetings and consulted with my project guide for suggestion which I implied in this project as it made me easier to achieve the objective that project was meant to achieve. I submitted the project report to the required authority of the institution after the completion of the project.

CE 1.5

The project was conducted under the authority and supervision from the members of the institution. Following is the chart that shows the organizational hierarchy, under which the project has been conducted,

CE 1.6

The list of duties that were executed to achieve the project’s objectives is mentioned below in brief points:

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  To review the literature on this matter for the possible way that can be taken to provide the solution.
  
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  To finalize a components and circuits to be used in the system.
  
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  To determine the working condition and parameters of surrounding that system will be operated on.
  
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  To design the circuit of the system using Proteus.
  
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  To program and burn it in microcontroller to make it perform specific tasks for the system.
  
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  To design the PCB board of the system and assemble the circuit by connecting finalized components.
  
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  To install the system in the real environment and run demo operation to record results to verify the achievements of the objectives.
  

C. PERSONAL ENGINEERING ACTIVITY

CE 1.7

I designed the system using Arduino Nano microcontroller board based on atmega328 microcontroller. The basic design of the project is based on use of Perturb and Observe model to obtain a point of maximum power in the solar panel. The energy generated through a solar panel is the function of light and temperature. The idea associated with model is that I program the system to measure the voltage of solar panel at few points to obtain a point, where the intensity of light is highest and reaches all over the panel equally. For charging of the battery from solar panel, I used a buck converter with bootstrap circuit. I designed two sensors to detect maximum current and voltage at one point. I programmed the microcontroller to compare the voltage levels at two points. I used a servo motor to move the panel to the point of maximum power.

CE 1.8

I used my knowledge of electronics engineering in this project. Within the duration of my involvement in this project, I programmed microcontroller, designed dedicated circuits to perform the task required specifically for this project, designed circuits and assembled the circuits to bring the whole system into reality. I used proteus and Arduino IDE to design and simulate circuit and program microcontroller respectively. I studied several journals and papers published in this matter to gain a deeper insight of the project. I consulted with my project guide and supervisor on this matter to take advice from them in tasks to perform for betterment of the project. I reviewed 1801-2013 – IEEE standard. I depended upon 31.180 standards which is an ISO standard for the assembly of printed circuit boards. I reviewed ISO 9488:1999 standard for reliability in solar panels.

CE 1.9

CE 1.9.1

I designed the project to use servo motors, few sensors and LCD display to perform the task it is supposed to perform. The servo motor rotates the panel bit by bit where the sensors measure the reading of current and voltage. The system compares the power at a point to the power from the previous point. When a point where there is maximum power is reached, the motor stops the panel and locks the point with maximum power to charge the battery. I used a LCD display to show the value of voltage and current at a particular point. For the voltage and current sensors I designed circuits using reference value of voltage from the panel to be 5V.

CE 1.9.2

As the system is focused on charging the battery, I supplied the power supply of the microcontroller through the battery. On the other hand, I used 7805 voltage regulator IC to power sensors, motor and the LCD display. I used diodes and capacitors to generate 5V from the battery. Figure below shows the design of the circuit I used,

CE 1.9.3

The sensors I used in the system are designed keeping in mind that ADC of the Arduino was to be used, which means that it could take up to 5V. So voltage sensor circuit had to be scaled down to 5V to be readable by microcontroller. To perform this action I used zenner diode and a capacitor for the purpose of filtration.

CE 1.9.4

For current sensing, I used a shunt resistor. While the shunt resistor taken was of 0.1 ohm, so the maximum voltage drop across it would be,

To use the full potential of the ADC of microcontroller, I used an op-amp which was LM-358 Op-amp. I set the op-amp to inverting configuration to protect the microcontroller from negative voltage drops across the shunt. I used following mathematical equation to find the appropriate op-amp with required gain.

CE 1.9.5

I designed the system used Proteus by finding the components in the library of proteus and connecting each component. I set the parameter of the components and ran a simulation of the circuits for the verification of the working of the components. I went back and forth with the design and simulation to find the circuit that worked with the purpose of the system. I connected the Power and ground pin to the Vcc and GND pin of the microcontroller and the controller pin of the motor to the data pin 9 of the microcontroller. I connected voltage sensor’s and current sensor’s output pins with the microcontroller’s A0 and A1 pins. I established the connection of the data pins D4-D7 of the LCD display to the data pins of the Arduino ranging from D2-D5. I supplied the Vcc and ground of the Display to the 5v and ground of the Arduino. I used a 10k pot to optimize the contrast of the display.

CE 1.9.6

I programmed the microcontroller to perform operations to achieve the task of the project. I used Arduino IDE and the instruction set provided by C language to write specific codes. The major task for microcontroller was to compare the power from the current and voltage sensor to the previous point and locate the point of maximum power by moving the panel using the servo motor. As the method implied in the project is Perturb and Observe, I followed following flowchart to write the code of the project to the microcontroller.

CE 1.9.7

After the programming of the microcontroller I burned the program into the microcontroller using Arduino IDE software. I turned the power of the system ON and installed the panel in open sky. I set the placement of the panel such that the way of rotation of panel happens through east to west. The panel moved through east to west bit by bit to till it found the maximum intensity of light. I found that battery charged faster than the usual time noted during the time of its use without MPPT.

CE 1.10 TECHNICAL PROBLEMS AND SOLUTIONS

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  During the demo operation of the circuit I found that there was no reading from the voltage sensor through the LCD display installed in the system. I checked the components using a multimeter for discontinuity in the circuit and found that the zenner diode in the voltage sensor was defective. I changed the zenner diode to a new one and the system worked flawless after that.
  
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  As the day passed to end, the power from the panel eventually was found to be lesser than the earlier point of time. To address this conflict I set the instruction code on the microcontroller to check and compare the voltage values too because of which the system became more efficient and reliable.
  

CE 1.11 CREATIVE WORK

I used a LM358 operational amplifier to make the maximum use of the ADC port of the microcontroller. Initially, the shunt offered only 0.5V of voltage and since ADC of microcontroller supports 5V, I used the op-amp to amplify the voltage to use the ADC pin of microcontroller more efficiently.

CE 1.12

It would have been impossible to conduct this project without coordination and support from the all members of the team and the project I guide. I held team meetings and discussed about ways about how this project could be made better. I recorded the steps taken and the work done in the entire duration of the project to keep the work well managed and organized. I studied journals and papers on this matter for knowledge of the ways that can be taken into consideration while work was done. I received support and motivation from project guide and supervisor who provided me with suggestions that I implied to make project better. I also received support from faculty members, library staffs and laboratory staffs in the entire involvement in this project.

D. SUMMARY

CE 1.13

I performed different task in the duration of the project to bring the project to the reality from the scratch. I made the design of the circuit, programming of the microcontroller, design and assembly of the PCB board in the project. Within my work in the project I learned the working pattern and the way how an idea can be turned into reality. I was able to ascertain the importance of programming and dedicated circuits for a system by the end of this project.

CE 1.14

It was proposed to design a system that could achieve an efficient model of system that could charge the battery faster and with maximum efficiency. With use of servo motor, solar panel, voltage and current sensor and a microcontroller, I completed this task through this system that is discussed here. With power matching and impedance matching the project utilizes the most of the energy that a panel can harvest, hence, assuring the achievement of objective.

CE 1.15

I learned and reviewed about this topic through various literature published in the past. I acquired the knowledge of programming a microcontroller and designing the circuit from books that I studied in my educational career. I learned the way of tackling the problems and errors that show up in nay task that one ventures.