ABSTRACT The project is designed to automatically supply continuous power to a load through one of the three sources of supply that are: solar, mains and generator or to combine the sources to supply the load all together at the same time. The three socket outlets represent the three sources. The sockets outlets are connected to three step down transformers which reduce the input 230V or 240V to 12Vac. These 12Vac are rectified and regulated to 5Vdc which act as an input to the microcontroller. Once the microcontroller recognize the present of a given source, a relay module is switch to an ON position. In case all the three sources are available, an android app is used to select the source of choice. When the amount of load demand increases beyond what can be handle by one source, a mobile app is used to bring on board another of the remaining two sources so as to meet the load demand. A filament bulbs were used as a load for demonstration purpose which draws power from solar. When solar fails to supply power, automatically the source will shift to main grid and if main grid fail, the load will automatically be supply by generator. But if solar come back when any one of the two sources is ON, the system will automatically shift to solar. The output of any source is connected to voltage stabilizing circuit which stabilize the voltage to 220Vac by a mean of an auto-transformer which has many taps. When there is any fluctuation in the input voltage, the voltage sensor will activate the relays to switch between the taps of an auto-transformer so as to either reduce or increase the incoming voltage so that the load voltage requirement is met. From the stabilizing circuit, the load is connected through an overload protector circuit which monitor the amount of current drawn by the load. Once the current goes beyond normal value, the last load connected is automatically isolated from the source while leaving the original part of the circuit connected. At the same time a message is sent to the operator by GSM notifying that the circuit is overloaded. The operator can decide to operate the loads by mean of GSM or by sending a text message “normal” to restore the system operation to use an android app.
TABLE OF CONTENTS
DECLARATION ...................................................................................................i
APPROVAL ........................................................................................................ ii
DEDICATION.................................................................................................... iii
ACKNOWLEDGMENT......................................................................................... iv
TABLE OF CONTENTS ........................................................................................ v
LIST OF FIGURES............................................................................................viii
LIST OF TABLES............................................................................................... ix
LIST OF ABBREVIATION OR NOMENCLATURE..................................................... x
ABSTRACT ........................................................................................................ x
CHAPTER ONE.............................................................................................1
INTRODUCTION .........................................................................................1
1.0 INTRODUCTION ..........................................................................................1
1.1 BACKGROUND OF THE STUDY......................................................................1
1.2 STATEMENT OF THE PROBLEM ....................................................................2
1.3 OBJECTIVES OF THE STUDY ........................................................................3
1.3.1 General Objective .....................................................................................3
1.3.2 Specific objectives.....................................................................................3
1.4 RESEARCH QUESTIONS ...............................................................................3
1.5 SIGNIFICANCE OF THE PROJECT..................................................................3
1.6 PROJECT JUSTIFICATION ............................................................................4
1.7 SCOPE OF THE PROJECT..............................................................................4
1.7.1 Time scope...............................................................................................4
1.7.2 Context scope...........................................................................................4
1.7.3 Geographical Scope...................................................................................5
1.8 ASSUMPTIONS AND LIMITATIONS................................................................5
CHAPTER TWO............................................................................................6
LITERATURE REVIEW.................................................................................6
2.0 INTRODUCTION. .........................................................................................6
2.1 CONCEPTS, DEFINITIONS AND DESCRIPTIONS.............................................6
vi
2.1.1 Automatic phase selector...........................................................................6
2.1.2 Voltage Stabilizer ......................................................................................6
2.1.3 Overload protection...................................................................................7
2.2 RELATED LITERATURE OR EXISTING TECHNOLOGY......................................7
2.3 INSTRUMENTATION/ MAJOR COMPONENTS USED. .......................................9
2.3.1 Bluetooth module (hc-05)........................................................................ 16
2.3.2 GSM SIM900A......................................................................................... 16
2.3.3 Microcontroller........................................................................................ 20
2.3.4 Liquid Crystal Display .............................................................................. 21
2.3.5 Step-Down Transformer .......................................................................... 22
2.3.6 Voltage regulator LM7805........................................................................ 23
2.3.7 Bridge Rectifier....................................................................................... 24
2.3.8 Filters..................................................................................................... 25
2.3.9 Relay...................................................................................................... 25
2.3.10 Light Emitting Diodes (LEDs) ................................................................. 26
2.3.11 Diodes (IN4007) ................................................................................... 26
2.3.13 Capacitors ............................................................................................ 27
2.3.14 Acs712 current sensor........................................................................... 18
Working of acs712 current sensor .................................................................... 18
Pin diagram of acs712 Hall Effect current sensor ............................................... 19
2.4 OBSERVATIONS IN THE MOST RECENT PROJECT........................................ 28
2.5 WEAKNESS OF RECENT PROJECTS. ............................................................ 28
2.6 ADVANCEMENT OF THE RECENT PROJECT.................................................. 29
CHAPTER THREE.......................................................................................30
METHODOLOGY ........................................................................................30
3.0 INTRODUCTION ........................................................................................ 30
3.1 Research Design........................................................................................ 30
3.1.1 Data Interpretation and Analysis .............................................................. 31
3.1.2 Development of the Project Design. ......................................................... 31
3.2 Power Supply Circuit .................................................................................. 43
3.2.1 Transformer ........................................................................................... 43
vii
3.2.2 Bridge Rectifier....................................................................................... 43
3.2.3 Filter Capacitor ....................................................................................... 44
3.2.4 Voltage Regulator LM7805/LM7805A........................................................ 44
3.2.5 Resistor.................................................................................................. 44
3.3 Logic design .............................................................................................. 45
CHAPTER FOUR ........................................................................................48
TESTING, RESULTS AND DISCUSSION.....................................................49
4.1 HARDWARE TESTING ................................................................................ 49
4.1.1 Continuity Test ....................................................................................... 49
4.1.2 Power on Test ........................................................................................ 49
4.2 RESULTS................................................................................................... 50
4.2.1 DC power supply..................................................................................... 50
4.2.2 Automatic Phasor Selector Controlled by Automatic Mode.......................... 50
4.2.3 Automatic Phasor Selector Controlled by Android (Bluetooth) Mode ........... 51
4.2.4 Automatic Voltage Stabilizer .................................................................... 51
4.2.5 Automatic Overload Protection Controlled Using Bluetooth ........................ 52
4.2.6 Automatic Overload Protection Controlled Using GSM................................ 52
4.3 Discussion ................................................................................................. 53
CHAPTER FIVE..........................................................................................55
CONCLUSIONS AND RECOMMENDATIONS ..............................................55
5.0 Conclusions ............................................................................................... 55
5.1 RECOMMENDATIONS................................................................................. 55
CHAPTER SIX.................................................................................................. 56
REFERENCES................................................................................................... 56
APPENDICES ................................................................................................... 58
APPENDIX A: SOURCE CODE............................................................................ 58
Appendix B: Gantt chart showing the Project Timeline ....................................... 88
APPENDIX C: PROJECT BUDGET....................................................................... 90