300W DC to DC Converter for Use in AC Inverters · PDF file300W DC to DC Converter for Use in...
Transcript of 300W DC to DC Converter for Use in AC Inverters · PDF file300W DC to DC Converter for Use in...
300W DC to DC Converter for Use
in AC Inverters
A Major Qualifying Project Report:
Submitted to
WORCESTER POLYTECHNIC INSTITUTE
As a requirement for the
Degree of Bachelor of Science by:
_________________________
Seth Crocker
_________________________
Nathan Roux
Submitted on 08/01/2011
Approved By:
_________________________
Prof. Stephen J. Bitar
i
Abstract
The purpose of this project was to create a high voltage DC-DC converter for use in inverter
applications. Extensive background research was conducted to evaluate existing inverter device
functionality. Multiple prototypes were constructed to characterize losses and investigate ways to
maximize efficiency. Testing of the final prototype included load testing, thermal characterization,
efficiency evaluation, and noise level capture, with mixed results. Further work is required to provide
closed loop control, safety shut off and low battery warnings.
ii
Acknowledgements
We would like to thank the following people and parties for helping us with our project.
Our thanks first go out to the company Waste to Watts who came up with the problem of which
hopefully our project will be the solution. We wish the best of luck to them in their business, and hope
that it takes root and they make a great difference in the lives of the people in countries who are not
fortunate to have such a stable power infrastructure as we do here in the states.
Secondly we would like to thank our project advisor Professor Stephen Bitar, for overseeing our
project from the initial research to this paper. His time and effort as well as his advice and guidance
undoubtedly were the driving force behind our project.
Lastly we would like to thank the ECE department and WPI as a whole for our education and
help with understanding our material without which we would not possess the tools required for the
completion of this project.
iii
Table of Contents Abstract ...................................................................................................................................................... i
Acknowledgements ................................................................................................................................... ii
Table of Figures ......................................................................................................................................... v
Table of Tables ......................................................................................................................................... vi
Table of Equations ................................................................................................................................... vi
1 Introduction to Waste to Watts ........................................................................................................ 1
1.1 Our interaction with Waste to Watts........................................................................................ 1
2 Introduction ...................................................................................................................................... 2
2.1 Introduction to DC-DC Converters ............................................................................................ 2
2.2 Types of DC-DC Converters ....................................................................................................... 2
2.3 Research Space/ Goals .............................................................................................................. 8
2.4 Purpose of Circuit ...................................................................................................................... 8
2.5 Prior Art ..................................................................................................................................... 8
2.6 Real World Parts ..................................................................................................................... 13
2.7 Safety Standards ..................................................................................................................... 13
3 The DC-DC Converter Type We Chose ............................................................................................ 17
3.1 Advantages and Disadvantages with Our Possible Choices .................................................... 17
3.2 Our final decision .................................................................................................................... 18
4 System Level Design ........................................................................................................................ 19
4.1 How it works (Block Diagram Level/ qualitative explanation) ................................................ 19
4.2 Control Chips compatible with our design .............................................................................. 21
4.3 Detailed Front End and Transformer Bias Design ................................................................... 23
4.4 Detailed Switch Control Design ............................................................................................... 24
4.5 Transformer and Output Filtering Design ............................................................................... 25
5 Simulations ...................................................................................................................................... 26
5.1 Spice Models ........................................................................................................................... 26
5.2 Basic Realistic Transformer Model.......................................................................................... 26
5.3 DC-DC Boost Converter Model ............................................................................................... 27
5.4 Two-Stage DC-DC Converter ................................................................................................... 29
iv
5.5 V2.2 Prototype primary side ................................................................................................... 30
6 Testing/results ................................................................................................................................ 33
6.1 Potential Components ............................................................................................................ 33
6.2 V0 ............................................................................................................................................ 34
6.3 V2 ............................................................................................................................................ 38
6.4 V2.1 ......................................................................................................................................... 42
6.5 V2.2 ......................................................................................................................................... 45
6.6 Coil testing .............................................................................................................................. 48
7 Future Work/Improvements ........................................................................................................... 51
7.1 Safety ...................................................................................................................................... 51
7.2 Efficiency ................................................................................................................................. 51
7.3 Additional Functionality .......................................................................................................... 52
7.4 Conclusion ............................................................................................................................... 53
8 Conclusion ....................................................................................................................................... 54
9 Appendix A ...................................................................................................................................... 55
10 Appendix B: Waste to Watts ....................................................................................................... 57
10.1 Company Overview* ............................................................................................................... 57
10.2 Business Description and Vision ............................................................................................. 58
10.3 Product Description- Enzi ........................................................................................................ 59
11 References .................................................................................................................................. 61
v
Table of Figures
Figure 1: Basic boost converter schematic diagram ..................................................................................... 2
Figure 2: Buck boost converter schematic diagram...................................................................................... 4
Figure 3: uk converter schematic diagram ................................................................................................. 5
Figure 4: SEPIC