1 
Linear Stirling Generator 
Feasibility Study for Distributed Power Generation 
UNIVERSITY OF MORATUWA. SRI LANKA 
MOMTUWA 
Supervised by 
Dr. A.M.I Munindradasa 
Dr. Rohan Munasinghc 
Project Work by 
K I M (iunawardana 
MEng / PG Dip Electronics & Telecommunication 
Department of Electronics and Telecommunication 
University of Moratuwa 
l niversit) t>\ M o r a t u w a 
I 
91263 
9 1 2 6 3 
ACKNOWLEDGEMENT 
Success of this project work should be a tribute to late Dr.Amith Munindradasa for 
introducing this challenging project which he himself was greatly enthusiastic about. 
Without his unshaken courage and par excellent engineering intuition it would have been 
very difficult to carry forward this project. With unexpected demise of Dr. Munindradasa 
support and guidance given by Dr. Rohan Munasinghe should be signified with the 
highest gratitude. 
Further I would like to express my sincere thanks to all my teachers of the Department of 
Electronic and Electrical Engineering at the University of Moratuwa for their fullest 
support and corporation extended. 
I thank Mr. Janaka Mangala of Mechanical Engineering Department University of 
Moratuwa for supporting me by allowing me to make use the wire cut EDM machine to 
turn out several components. 
I cannot forget the pain taken by Mr. Zhyad who helped me with the lathe machine work 
at odd hours of the day and tolerating several design changes that was inevitable for this 
research project. 
1 thank my CEO and my company Lanka Transformers Ltd for extending their 
corporation by allowing me to carry out experimental work within company premises 
utilising its resources. 
Contents 
C O N T E N T S 1 
1 I N T R O D U C T I O N T O S T I R L I N G E N G I N E 3 
1.1 Background of Stirling engines 3 
1.2 Importance of Stirling Engine 3 
1.3 Free piston Type 3 
2 R E S E A R C H O B J E C T I V E 6 
2.1 Novel Findings 6 
3 T H E O R E T I C A L C A L C U L A T I O N S , D E S I G N A N D S I M U L A T I O N O F L I N E A R 
S T I R L I N G G E N E R A T O R 7 
3.1 Calculations of the Stirling Engine 7 
3.2 Generator Design 11 
3.3 Modeling the Stirling Cycle and Striling Generator 14 
3.4 Simulation of the Stirling Engine on MATLAB Simulink 17 
3 4 . 1 M o d e l i n g St ir l ing G e n e r a t o r 18 
3.5 Simulation of the Stirling Generator on MATLAB Simulink 20 
4 M E T H O D O L O G Y 22 
4.1 Initial Experiments that were made to test the components and their practical limitations 22 
4.2 Design of the Electronic driver system on OrCAD 24 
4.3 Programming the Micro Controller 27 
4.4 Flextu re bearing for linear motion tuning 30 
5 E X P E R I M E N T A L R E S U L T S 31 
5.1 Magnetisation of the Generator 31 
5.1 .1 R u n n i n g the L inear m o t o r 3 3 
5 . 1 . 2 E f f i c i e n c y C a l c u l a t i o n L inear m o t o r G e n e r a t o r 3 6 
6 DISCUSSION 38 
6.1 Future Work 39 
6.2 Conclusion 39 
7 REFERENCES 40 
8 APPENDIX 42 
8.1 Stirling Cycle and Elementary Components of Stirling Engine 42 
8.2 PIC Microcontroller 47 
8.2.1 Anatomy of the micro controller Program 50 
8.2.2 Assembler Program for the H bridge Driver 52 
• 
2