SOLAR ELECTRIC AMBULANCE VAN TO ASSIST RURAL EMERGENCIES OF BANGLADESH - A Complete Off-Grid Solution A Thesis Submitted to the Department of Electrical and Electronic Engineering of BRAC University By Rahmeen Tarek-12321003 Afra Anjum-12321075 MD. Abrar-Ul-Hoque-12321058 Forkan Abdur Rahim-12121137 Supervised by Dr. A. K. M. Abdul Malek Azad Professor Department of Electrical and Electronic Engineering BRAC University, Dhaka. In partial fulfilment of the requirements for the degree of Bachelor of Science in Electrical and Electronic Engineering Fall 2015 BRAC University, Dhaka i Declaration We thus proclaim that our thesis titled "Solar Electric Ambulance Van to assist rural emergencies in Bangladesh- A complete off-grid solution", submitted to the Department of Electrical and Electronics Engineering of BRAC University in partial fulfilment of the Bachelors of Science in Electrical and Electronics Engineering, is our own work. The work has not been introduced somewhere else for evaluation. The materials gathered from different sources have been recognized here Signature of Supervisor Signature of Author ............................................. ........................................... Dr. AKM Abdul Malek Azad Rahmeen Tarek Signature of co-authors ............................................ Afra Anjum ............................................. MD. Abrar-Ul-Hoque ............................................. Forkan Abdur Rahim ii Acknowledgement We are grateful to our thesis supervisor Dr. A.K.M. Abdul Malek Azad, Professor, Dept. of Electrical and Electronic Engineering (EEE), BRAC University, for guiding us in completion of our thesis. We are grateful to BRAC University for giving us the necessary equipments for completion of this thesis and financing this venture embraced by Control and Applications Research Centre (CARC). Lastly, we want to thank all the project engineers of CARC for their support. iii Abstract Rickshaws are an essential method of transportation in Bangladesh. When it was altered to electrically assisted rickshaw, it attained popularity but was soon discontinued due to overconsumption of power. Therefore, Control and Applications Research Centre (CARC), BRAC University has proposed the concept to give a complete off-grid arrangement by utilizing the PV array, torque sensor pedal, and solar battery charging station and implementing it in a solar electric ambulance van as a significant part of individuals who live in the provincial zones, where the likelihood of reaching the hospital on time is very low due to lack of mode of transportation. The torque sensor pedal lessens the over-utilization of battery-bank. The intelligent control framework reduces the human force and diminishes the over-utilization of engine. PV panel is introduced on top of the van to share a part of the power and a solar battery charging station is installed to make the entire framework totally autonomous of national grid. This paper consists of the design and implementation of the idea proposed by CARC. iv TABLE OF CONTENTS  Acknowledgement............................................................................................................iii  Abstract.............................................................................................................................iv  List of Figures...................................................................................................................ix  List of Abbreviations........................................................................................................xi  List of Tables…………………………………………………………………………....xii CHAPTER 1: Introduction 1.1 Introduction to rickshaw van.............................................................................................1 1.2 Impact of rickshaw vans in the Economy of Bangladesh.................................................2 1.3 Motivation.........................................................................................................................3 1.4 Overview of the content....................................................................................................4 CHAPTER 2: Overview of the Whole System 2.1 Introduction................................................................................................................................5 2.2 Components used 2.2.1 The Batteries....................................................................................................................7 2.2.2 The Motor........................................................................................................................8 2.2.3 The Controller Box..........................................................................................................8 2.2.4 The Throttle.....................................................................................................................9 2.2.5 The Power Key and Charge Indicator..............................................................................9 2.2.6 The Solar Panel..............................................................................................................10 2.2.7 The Charge Controller...................................................................................................10 2.2.8 The Torque Sensor.........................................................................................................11 2.2.9 The Brake System..........................................................................................................12 2.2.10 Light System................................................................................................................12 2.2.11 Helical Spring..............................................................................................................13 2.2.12 Accessories of the Ambulance Van.............................................................................13 2.3 Conclusion...............................................................................................................................14 CHAPTER 3: Chronological Development of Rickshaw 3.1 Introduction..............................................................................................................................15 3.2 Traditional Manual Rickshaw..................................................................................................15 3.3 Electrically Assisted Rickshaw................................................................................................16 3.4 Torque Sensor Hybrid Rickshaw.............................................................................................16 3.5 Hybrid Rickshaw with PV support..........................................................................................17 3.6 Solar Electric Tri-wheeler Van................................................................................................18 3.7 Solar Electric Ambulance Van................................................................................................19 3.8 Comparison of the designed system with the existing one......................................................20 3.9 Conclusion...............................................................................................................................20 v Chapter 4: Design 4.1 Introduction...........................................................................................................................21 4.2 Design...................................................................................................................................21 4.3 Explanation...........................................................................................................................23 4.4 Dimension.............................................................................................................................24 4.5 Features.................................................................................................................................24 4.6 Conclusion............................................................................................................................24 Chapter 5: Torque Sensor and PV Array of the System 5.1 Introduction..........................................................................................................................25 5.2 Introduction to the torque sensor..........................................................................................25 5.3 Features of torque sensor......................................................................................................26 5.4 Specifications........................................................................................................................26 5.5 Advantages of Torque Sensor Circuit...................................................................................26 5.6 Integration of Torque Sensor into the system.......................................................................27 5.7 Power Distribution................................................................................................................27 5.8 Design I of Torque Sensor....................................................................................................28 5.8.1 Circuit Diagram...........................................................................................................28 5.8.2 Explanation..................................................................................................................29 5.8.3 Torque Sensor Simulation Data..................................................................................29 5.9 Design II of Torque Sensor...................................................................................................29 5.9.1 Circuit Diagram...........................................................................................................30 5.9.2 Explanation..................................................................................................................30 5.10 Introduction to PV array.....................................................................................................30 5.10.1 Specifications.............................................................................................................31 5.10.2 Charge Controllers.....................................................................................................31 5.11 Block Diagram of the Whole System.................................................................................32 5.12 Explanation of Control Algorithm......................................................................................32 5.13 Conclusion..........................................................................................................................34 Chapter 6: Overview of the Solar Battery Charging Station 6.1 Introduction to the solar battery charging station.............................................................35 6.2 SOC: State of Charge of the Battery.................................................................................37 6.3 Replacement and Restoration of the Five-Wheeler’s Solar Batteries...............................38 6.4 Conclusion........................................................................................................................39 Chapter 7: Field Test 7.1 Objective..................................................................................................................................40 7.2 Procedure for attaining data.....................................................................................................41 7.3 Test data without any PV array assistance or aid from torque sensor pedal............................41 vi 7.4 Test data with only PV array assistance..................................................................................43 7.5 Test data with only aid from torque sensor pedal....................................................................44 7.6 Test data with both PV array assistance and aid from torque sensor pedal.............................46 7.7 Comparison with the solar electric tri-wheeler van.................................................................48 7.8 Conclusion...............................................................................................................................50 Chapter 8: Improvements on Existing Design 8.1 Introduction.............................................................................................................................51 8.2 Inability to take reverse gear...................................................................................................51 8.3 Inability to take sharp turn......................................................................................................52 8.4 Lack of grip on slippery road..................................................................................................53 8.5 Impact protection....................................................................................................................54 8.6 Inefficient braking system.......................................................................................................54 8.7 Conclusion..............................................................................................................................55 Chapter 9: Conclusion 9.1 Conclusion.............................................................................................................................56 9.2 Work projection.....................................................................................................................56 9.3 Project recognition.................................................................................................................57 REFERENCES......................................................................................................58 vii APPENDIX Appendix A: Wiring Diagram Appendix B: Torque Sensor Diagram Appendix C: Flow Diagram of Chronological Development of Solar Electric Ambulance Van Appendix D: Different views of the vehicle Appendix E: Components of the vehicle Appendix F: Test Data without any PV Array Assistance or Aid from Torque Sensor Pedal viii LIST OF FIGURES Fig 1.1 Traditional Rickshaws [1] Fig 1.2 Traditional Rickshaws [2] Fig 1.3 Local Carts used as ambulance in rural areas Fig 1.4 City Ambulances Fig 2.1 Side View Fig 2.2 Front View Fig 2.3 Inside View Fig 2.4 Batteries Fig 2.5 BLDC MOTORS Fig 2.6 Controller Box Fig 2.7 Identification of the controller cables Fig 2.8 Throttle Fig 2.9 Charge Indicator Fig 2.10 Solar panel Fig 2.11 Charge Controller Fig 2.12 Torque Sensor Fig 2.13 Traditional Hand Clutch Fig 2.14 Rear Wheel Brake Fig 2.15 Back Indicator lights Fig 2.16 Helical Spring Fig 2.17 (a) Tube light, (b) Headlight, (c) Fan, (d) Siren, and (e) First Aid Box Fig 3.1 Traditional Rickshaw Fig 3.2 Electrically Assisted Rickshaw Fig 3.3 Torque sensor based Electric Rickshaw Fig 3.4 Electric Rickshaw with PV panel installed in ‘’flat state’ Fig 3.5 Solar Electric Tri-wheeler Van Fig 3.6 Solar Electric Ambulance Van Fig 3.7 Modified Solar Electric Ambulance Van Fig 3.8 Solar Electric Tri-wheeler Van [12] Fig 4.1 Side view of the Ambulance van Fig 4.2 Rear view of the Ambulance van Fig 4.3 Inside view of the Ambulance van Fig 4.4 Skeletal Diagram of the Ambulance Van Fig 5.1 Torque Sensor with module Fig 5.2 Torque sensor after being integrated Fig 5.3 Block diagram of power distribution and signal flow Fig 5.4 External circuit of Torque Sensor Fig 5.6 Circuit Diagram of Design II Fig 5.7 Charge controllers ix Fig 5.8 Block diagram of integration of torque sensor and PV array into the system Fig 5.9 Flowchart of control algorithm Fig 6.1 Solar panels being charged on the rooftop of BRAC University Fig 6.2 Working procedure of solar battery charging station Fig 6.3 Operation of Solar battery charging station Fig 6.4 SOC of battery [15] Fig 6.5 Conventional trolley used for transport purpose Fig 6.6 Conveyer belt that can be used for roller system purpose [16] Fig 7.1 Data Attaining Procedure Fig 7.2 Voltage and current from first set of batteries Fig 7.3 Voltage and current from second set of batteries Fig 7.4 Power supplied by first set of batteries Fig 7.5 Power supplied by second set of batteries Fig: 7.6 Load power for first set of batteries without PV support and torque sensor Fig 7.7 Load power for second set of batteries without PV support and torque sensor Fig 7.8 Comparison of energy saving from different field tests Fig 7.9 Energy contribution of battery, PV panel and torque sensor Fig 7.11 Projected distance of ambulance van for 50% DOD, in comparison to the ambulance van Fig 8.1 Motor controller Fig 8.2(a) Initial built skeletal diagram (b) Modified design skeletal diagram Fig 8.3 New chassis design Fig 8.4 Grid tyres for optimal grip Fig 8.5 Using foam and Teflon in frame Fig 8.6 Disk brakes Fig 9.1 Extra features to assist future development x