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Adaptive Impedance Matching Circuit for Narrowband Power Line Communication

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Adaptive Impedance Matching Circuit for Narrowband Power Line Communication Department of Electrical and Computer Engineering Adaptive Impedance Matching Circuit for Narrowband Power Line Communication Chin Pin Rui This thesis is presented for the Degree of Master of Philosophy (Electrical and Computer Engineering) of Curtin University October 2013 To the best of my knowledge and belief this thesis contains no material previously published by any other person except where due acknowledgment has been made. This thesis contains no material which has been accepted for the award of any other degree or diploma in any university. ______________________________________ ______________________ Author Date i Adaptive Impedance Matching Circuit for Narrowband Power Line Communication by Chin Pin Rui Submitted to the Department of Electrical and Computer Engineering in October, 2013 in partial fulfilment of the requirements for the degree of Master of Philosophy (Electrical and Computer Engineering) ABSTRACT Power line communication is used in various electrical systems, from high-voltage network to the low-voltage network to transfer information. It is a wired communication that is comparable with the wireless communications because information is modulated with carrier wave before being injected into the communication channels. However, the noise level and impedance mismatch are the main concerns in this technology, particularly in the low voltage network or in residential area. Even though the noise level and the impedance mismatch of a power line communication system can be controlled using a band-pass filter and an impedance matching circuit respectively, the impedances of power line in residential area are time and location dependent, and therefore it is rather difficult to design a circuit that allows maximum power transfer in the system all the time. In this thesis, two new adaptive impedance matching circuits are proposed for narrowband power line communication. These new methodologies are derived based on a RLC and a LCRC circuits. Both concepts are designed to achieve a simpler configuration and a higher matching resolution. It is concluded that the RLC band-pass filter impedance matching network is suitable for the implementation of a narrowband power line communication network that consists of pure resistive impedance. Meanwhile the LCRC impedance matching network is designed to match the signal source impedance to both the resistive and reactive load impedances, thus it is more practical to be used in a residential house. ii ACKNOWLEDGEMENTS Firstly, I would like to express my gratitude to my supervisors, Prof. Nader Nassif Barsoum and Dr. Wong Kiing Ing for their valuable advice and guidance throughout my research. Their continuous feedbacks and encouragements have been a great contribution to the success of this thesis. Although Prof. Nader left Curtin Sarawak during the period of my master degree study, but he never give up on me. He continues his supervision of me through email communication. From the School of Engineering and Science, I would like to acknowledge my friend, who is also the Laboratory Technical Officer Mr. Daniel Wong Sing Tze and my student, Mr. Wong Tze Jia for assisting me in the experimental analysis of my research. At the same time I would like to acknowledge my colleague, who is also my buddy, Mr. Arthur Wong for assisting me in the theoretical and mathematical analysis of my thesis. In addition to that, I would like to thank my friends, Mr. Peter Wong Jian Sheng and Mr. Alexander Lau for proofreading my thesis. And of course I would like to thank all the lecturers and staffs in the school for their feedbacks, supports and assistance that had contributed greatly to the completion of my thesis. I also want to grab this opportunity to express my thanks to the great people around me, especially Uncle Chan Kwok Mow, Aunty Sin Sai Liong, Pastor Lim Thien Leong, the Curtin Ministry, Young Adult Ministry and the people from Piasau Baptist Church for their continuous encouragement and support throughout the years. I wish to thank my family for their love and support towards me. They are my greatest strength and motivation during my thesis-writing. Last but not least, I want to thank God for His unconditional love and blessing to me and the people around me! iii Copyright Acknowledgement Imagery downloaded from the internet has been used in this chapter for testing purposes in accordance with Section 40 of the Australian Copyright Act of 1968, which allows fair dealing of artistic work for purpose of research or study. The following persons are herewith acknowledged as the respective copyright holders: Test image in Figure 2.1 is © Khairanirani. Test image in Figure 2.2 is © Software Design and Embedded System Tools. Test image in Figure 2.3 is © Don Shaver. Test image in Figure 2.4 is © Hendrik C Ferreira et al. Test image in Figure 2.5 is © Bogdan Baraboi. Test image in Figure 2.6 is © Farrokh Najmabadi. Test image in Figure 2.9 is © IulianRosu. Test image in Figure 4.2 is © Yuhao Sun. Test image in Figure 4.3 is © Hank Zumbahlen. iv Content Abstract ............................................................................................................................ ii Acknowledgements .......................................................................................................... iii CHAPTER 1 Introduction .................................................................................................. 1 1.1 Aim and Approach .............................................................................................. 3 1.2 Significance and Contribution ............................................................................. 4 1.2.1 New Algorithm of Adaptive Impedance Matching Method ........................ 4 1.2.2 Simplification of the Existing Formula ........................................................ 5 1.3 Thesis Outline ...................................................................................................... 6 CHAPTER 2 Background .................................................................................................. 7 2.1 Power Line Communication ................................................................................ 7 2.1.1 Narrowband Power Line Communication ................................................. 12 2.2 Problem Statement of Power Line Communication .......................................... 13 2.2.1 High Noise Level ....................................................................................... 13 2.2.2 Impedance Mismatch ................................................................................. 14 2.3 Solutions to the Problem Statement .................................................................. 15 2.3.1 Band-pass Filter ......................................................................................... 15 2.3.2 Impedance Matching .................................................................................. 17 2.4 Impedance Measurement Method ..................................................................... 19 CHAPTER 3 RLC Adaptive Impedance Matching Circuit ............................................. 21 3.1 Circuit Model .................................................................................................... 21 3.2 Digital Capacitor ............................................................................................... 22 3.3 Impedance Matching Algorithm ....................................................................... 23 3.4 Experiments ....................................................................................................... 26 3.4.1 Simulation Result ....................................................................................... 26 3.4.2 Measured Result ......................................................................................... 30 3.5 Summary ........................................................................................................... 34 CHAPTER 4 LCRC Adaptive Impedance Matching Circuit ........................................... 35 4.1 Circuit Model .................................................................................................... 35 4.2 Active Inductor .................................................................................................. 36 v 4.3 Impedance Matching Algorithm ....................................................................... 39 4.3.1 Mathematical Derivation to find R, C1 and C2 ........................................... 40 4.3.2 Mathematical Derivation to form relationship between R and L ............... 41 4.3.3 Mathematical Derivation to form relationship between C and L ............... 47 4.3.4 Effect of R and C on the filter response ..................................................... 48 4.3.5 Derivation of load impedance related to input parameters ........................ 55 4.3.6 Proposed algorithm of impedance matching .............................................. 58 4.4 Experiment ........................................................................................................ 59 4.4.1 Simulation Result ....................................................................................... 60 4.4.2 Measured Result ......................................................................................... 69 4.5 Summary ........................................................................................................... 73 CHAPTER 5 Conclusion ................................................................................................
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