DESIGN OF POWER LINE COMMUNICATION

SYSTEM

By

NUHA AHMED MAHDI MOHAMMED

INDEX NO. 124104

SUPERVISOR

PROF. SHARIEF BABIKER

A thesis submitted in partial fulfillment for the degree of B.Sc (HONS) in Electrical and Electronic Engineering (ELECTRONICS AND COMPUTER SYSTEMS ENGINEERING) University of Khartoum Faculty of Engineering OCTOPER 2017

DECLARATION OF ORGINALITY

I declare this report entitled “Design Of Power Line Communication System” is my own work except as cited in references. The report has been not accepted for any degree and it is not being submitted currently in candidature for any degree or other reward.

Signature: ______

Name: ______

Date: ______

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ACKNOWLEDGMENT

I would like to express my sincere gratitude to my supervisor prof. Sharief Fadul Babikir, for the guidance and support he provided throughout the project and related research, for his time, patience and kindness, and for providing me with the opportunity to work with him. It has been a great privilege and honor.

I am deeply grateful to my project partner,Alaa Abd Almoniem for her hard work, continuous support and the unforgettable times we have spent.

I also would like to give my gratitude to engineer Mahmoud Ibrabim for his continuous advice, systematic guidance, encouragement and support

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DEDICATION

To my parents, Colleagues and everyone who believed in me To the Five years of Fulfillment To the experience that can never be replaced

A big thank you.

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ABSTRACT

Power lines were originally designed to transmit power from the suppliers to the customers at low frequency (50 Hz or 60 Hz).

To improve the communication infrastructure, power lines can be utilized as communication channel.

This project aims to design and implement Power Line Communication system that consist of transmitter, receiver, coupling circuit and the Power lines as the communication medium.

Transmitter was designed to modulate data using Frequency Shift Keying (FSK) technique. Receiver on the other side will demodulate the signal using Phase Locked Loop (PLL). transceiver also perform multiple filtering and amplifying operations in order to repair signals that have been attenuated and affected by the noise after the transmission over power lines.

Coupling circuit is the heart of the system it was designed to insert the modulated signal from the transmitter into the power line and to extract it on the other receiver side .and to protect circuit from the high voltage low frequency signal (240v 50 hz).

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المستخلص

تم تصميم خطوط الطاقة أصال لنقل الطاقة من الموردين إلى العمالء في التردد المنخفض )50 هرتز أو 60 هرتز(.

لتحسين البنية التحتية لالتصاالت، يمكن استخدام خطوط الكهرباء كقناة اتصال.

يهدف هذا المشروع إلى تصميم و تنفيذ نظام اتصاالت يستخدم خطوط نقل الكهرباءلنقل بيانات رقمية.يتكون النظام من جهازي اإلرسال واالستقبال ودائرة اقتران وخطوط الطاقة كوسيلة االتصاالت.

تم تصميم المرسل بحيث يقوم بتعديل البيانات الرقمية المراد ارسالها باستخدام تقنية تكييف ازاحة التردد )FSK(. وسيؤدي المستقبل على الجانب اآلخر إلى إزالة تشكيل اإلشارة باستعمال حلقة الطور المقفل )PLL(. ويقوم جهازي اإلرسال واالستقبال أيضا بعمليات ترشيح وتضخيم متعددة من أجل إصالح اإلشارات التي تم توهنها وتأثرها بالضوضاء بعد اإلرسال عبر خطوط الكهرباء.

دائرة االقتران هي قلب النظام تم تصميمها إلدخال إشارة التضمين من المرسل في خط الطاقة واستخراجها في جانب المستقبل، و ايضا لحماية دائرتي االرسال و االستقبال من الجهدالعالي)240 فولت(.

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TABLE OF CONTENTS

DECLARATION OF ORGINALITY ...... ii Acknowledgment ...... iii DEDICATION ...... iv Abstract ...... v vi ...... المستخلص Table of contents ...... vii List of Figures ...... xi List of Tables ...... xii List of abbreviation ...... xiii 1 CHAPTER ONE: INTRODUCTION ...... 1 1.1 overview ...... 1 1.2 Problem statement ...... 1 1.3 Project objectives ...... 1 1.4 Thesis layout ...... 1 2 CHAPTER TWO: LITRETURE REVIEW ...... 3 2.1 PLC history...... 3 2.2 PLC applications: ...... 10 2.2.1 according to the frequency: ...... 10 2.2.2 According to the voltage: ...... 12 2.2.2.1 Low voltage or in-house: ...... 13 2.2.2.1.1 Home automation: ...... 13 2.2.2.1.2 Street lightening monitoring: ...... 13 2.2.2.1.3 Low cost inter-device peer-to-peer networking: ...... 13 2.2.2.2 Medium Voltage and Low Voltage: ...... 13 2.2.2.2.1 Utility: ...... 13 2.2.2.2.2 Broadband data transmission: ...... 14 2.3 PLC Types ...... 14 2.3.1 Ultra-narrow band plc ...... 15

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2.3.2 Narrowband plc...... 16 2.3.3 Broadband plc ...... 18 2.4 Plc standards ...... 19 2.4.1 CENELEC ...... 20 2.4.2 FCC ...... 21 2.4.3 IEEE ...... 21 2.4.4 IEC ...... 22 2.5 PLC protocols and Technologies ...... 23 2.5.1 X-10 ...... 23 2.5.1.1 Protocol description ...... 23 2.5.1.2 Disadvantages ...... 25 2.5.2 CsBus technology ...... 25 2.5.3 LonWorks technology ...... 25 2.6 PLC system components ...... 26 2.6.1 Modem ...... 26 2.6.1.1 Amplitude shift keying ASK ...... 26 2.6.1.2 Phase Shift Keying ...... 27 2.6.1.3 Orthogonal Frequency Division Multiplexing (OFDM) ...... 28 2.6.1.4 Frequency Shift Keying ...... 28 2.6.2 Coupling circuit ...... 29 Capacitive Coupling: ...... 29 Inductive Coupling ...... 29 3 CHAPTER THREE: METHODOLOGY AND DESIGN ...... 30 3.1 Design goals ...... 30 3.2 System components ...... 30 3.2.1 PLC Transmitter ...... 30 3.2.2 PLC receiver ...... 31 3.2.3 Coupling circuit ...... 31 3.2.4 Decoupling circuit ...... 31 3.2.5 Power lines ...... 31 3.3 Tools and instruments ...... 32

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3.3.1 Software tools ...... 32 3.3.1.1 Proteus 8.6 ...... 32 3.3.2 Hardware...... 32 3.3.2.1 Oscilloscope ...... 32 3.3.2.2 Function generator ...... 33 3.3.2.3 Breadboard ...... 34 3.3.2.4 Cpacitors and resistors ...... 34 3.3.2.5 NPN transistors ...... 35 3.3.2.6 Opamps ...... 35 3.3.2.7 VCO (lm566) ...... 35 3.3.2.8 PLL ...... 35 3.3.2.9 Timer 555 ...... 35 3.4 System design steps ...... 36 3.4.1 Step one: Generation of FSK signal ...... 36 3.4.1.1 Design 1: Using Multiplexer ...... 37 3.4.1.2 Design 2: Using 555 timer ...... 37 3.4.1.3 Design three: using Voltage Controlled oscillator (VCO) LM566 ...... 40 3.4.2 Step two: Demodulation ...... 43 3.4.2.1 Using Phase Locked Loop ...... 43 3.4.3 Step three: coupling circuit ...... 46 4 CHAPTER FOUR: RESULT AND DISCUSSION ...... 50 4.1 Overview ...... 50 4.2 Calculations ...... 50 4.2.1 FSK modulation ...... 50 4.2.1.1 Using timer circuit ...... 50 4.2.1.2 Using VCO circuit ...... 52 4.2.2 Demodulation using PLL:...... 54 4.2.3 Coupling circuit ...... 55 4.3 Discussion ...... 56 4.3.1 Transmitter ...... 56 4.3.2 Receiver ...... 59

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4.3.3 Coupling ...... 59 5 CHAPTER FIVE: CONCLUSION AND RECOMINDATIONS ...... 61 5.1 Conclusion ...... 61 5.2 Problems and solutions ...... 61 5.3 Future works ...... 61 References ...... 62

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LIST OF FIGURES

Figure 2.1: PLC system layers ...... 20 Figure 2.2: Representation of the X-10 signal ...... 24 Figure 2.3: tow packet of the X-10 protocol...... 24 Figure 2.4: Amplitude Shift Keying ...... 27 Figure 2.5: Phase Shift Keying ...... 27 Figure 3.1: Blocks of system components...... 31 Figure 3.2: proteus 8.6 ...... 32 Figure 3.3: oscilloscope ...... 33 Figure 3.4: Function generator ...... 33 Figure 3.5: Breadboard ...... 34 Figure 3.6: capacitors ...... 34 Figure 3.7: Resistors ...... 34 Figure 3.8: NPN transistor ...... 35 Figure 3.9: VCO LM566 ...... 35 Figure 3.10: FSK signal and data signal ...... 36 Figure 3.11: Multiplexor circuit ...... 37 Figure 3.12: 555 timer simulation ...... 39 Figure 3.13: Real Circuit ...... 40 Figure 3.14: LM566 circuit simulation...... 42 Figure 3.15: LM566 circuit implementation ...... 43 Figure 3.16: Block diagram of PLL...... 44 Figure 3.17: Phase Locked Loop components...... 44 Figure 3.18: 4046 PLL simulation ...... 44 Figure 3.19: coupling circuit simulation...... 47 Figure 3.20: modulation circuit connected to coupling circuit...... 48 Figure 3.21: demodulation circuit connected to coupling circuit...... 49 Figure 4.1: timer circuit output ...... 51 Figure 4.2: timer circuit output ...... 51 Figure 4.3: timer circuit with prober values ...... 51 Figure 4.4: real circuit result ...... 52 Figure 4.5: FSK modulation output ...... 53 Figure 4.6: VCO final circuit simulation ...... 53 Figure 4.7: transceiver circuit ...... 54 Figure 4.8: overall transceiver circuit results ...... 55 Figure 4.9: coupling circuit result ...... 56 Figure 4.10: Mux bad result ...... 58 Figure 4.11: Mux good result ...... 58

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LIST OF TABLES

Table 3-1: Applications of PLC ...... 12 Table 3-2: PLC Classifications ...... 15 Table 3-3: Frequency band for NB-PLC ...... 17 Table 3-4: Industrial specification of BB-PLC ...... 19 Table 3-5: CENELEC categories ...... 21 Table 5-1: coupling circuit parameters ...... 56

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LIST OF ABBREVIATION

AC Alternating current AM Amplitude Modulation AMI Advanced Metering Infrastructure AMR Automatic Meter Reading AMRA Automatic Meter Reading Association ANSI American National Standards Institute ASK Amplitude Shift Keying AT&T American Telephone and Telegraph BBPLC Broad Band Power Line Communication BPL Broad Band over Power Lies BPSK Binary Phase Shift Keying CSMA/CA Carrier sense multiple access with collision avoidance CTP Carrier Transmission over Power Line DCSK Differential Chaos Shift Keying DPSK Differential Phase Shift Keying DQPSK Differential Quadrature Phase Shift Keying DTOPL Data Transmission Over Power Lines FCC Federal Communication Commission FEC Forward Error Correction FFH Fast Frequency Hopping FSK Frequency Shift Keying GE General Electric HD High Definition HV High Voltage HVAC Heat Ventilation and Air Conditioning IEC International Electrotechnical Commission

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IEEE Institute of Electrical and Electronics Engineers ITU International Telecommunication Union LAN Local Area Network LMT Last Mile Telecommunication LV Low Voltage MAC Medium Access Control MCM Multiple Carrier Modulation MV Medium Voltage NARUC National Association of Regulatory Utility Commissioners NBPLC Narrow Band Power Line Communication OFDM Orthogonal Frequency Division Multiplexing PLCC Power Line Communication Carrier PLL Phase Locked Loop PRIME Power Line Related Intelligent Metering Evolution PSK Phase Shift Keying RCS Ripple Carrier Signaling SDO Standards Developing Organization SFSK Spread Frequency Shift Keying TDMA Time Division Multiple Access UNBPLC Ultra-Narrow Band Power Line Communication UPA Universal Power Line Association VCO Voltage Controlled Oscillator

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CHAPTER ONE INTRODUCTION

1 CHAPTER ONE: INTRODUCTION

1.1 overview the power line carrier communication system uses the existing AC electrical wiring as the network medium to provide high speed network access points almost anywhere there is an AC outlet. 1.2 Problem statement Power lines were originally devised to transmit electric power from a small number of sources (generators) to a large number pf sinks (consumers) in the frequency range of 50-60 Hz. Nowadays with the emergence of modem networking technologies and the need for information spreading, data transmission over power lines has seen a really big growth. The technologies already used for spreading information such as telephone wiring, Ethernet cabling, fiber optic and wireless have each its limitations in costs and reliability.

The advantage of using power lines for data transmission is that every building and home is already equipped with the power line and connected to the power grid.

1.3 Project objectives  Study of the possibility and visibility of using power lines as a solution for sending and receiving data.

 Design power line communication system. 1.4 Thesis layout This thesis is organized into 5 chapters:

Chapter 2 (Literature review): This chapter introduce the history of Power Line Communication and its applications and types. Also it reviews the protocols and technologies used in PLC.

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CHAPTER ONE INTRODUCTION

Chapter 3 (Methodology and Design): This chapter describes the goals of designing such a system, the system components, tools and instruments used and the steps of designing the PLC system.

Chapter 4 (results and discussion): This chapter shows the results of the simulation circuit design and the actual results of the real circuits. Also it discusses the results.

Chapter 5 (Conclusion): This chapter contains the thesis conclusion and expected future works.

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CHAPTER TWO LITRETURE REVIEW

2 CHAPTER TWO: LITRETURE REVIEW

2.1 PLC history The idea of utilizing power lines to carry signals is a very old invention. In 1838, the first remote electricity supply metering was proposed to check the voltage levels of batteries in an unmanned site of the London-Liverpool telegraph system. In 1897, the first PLC patent on power line signaling electricity meter was proposed in Great Britain [1]. In 1905, the remote reading of electricity meters using an additional signaling wire was patented in the USA. In 1913, the first products of electromechanical meter repeaters were launched commercially.

In 1920, the carrier frequency transmission of voice signal over high voltage (HV) power lines was deployed. The carrier transmission over power lines (CTP) was important for the management and monitoring tasks and also at the beginning of electrification the full-coverage of telephone network was not available. The frequencies used for CTP were between 15−500 kHz. Under favorable circumstances, it was possible to bridge the distance of 900 k.m between transmitter and receiver with the transmission power of 10 W (40 dBm). Firstly, only Amplitude Modulation (AM) was applied as it was simple and optimal for voice transmission [1]. Later, the telemetering and the telecontrolling systems were also implemented.

In 1927, the use of thermionic valves for metering was patented. From 1930 onwards, the ripple carrier signaling (RCS) system was applied in the Medium Voltage (MV) and Low Voltage (LV) networks where its main functions were the load distribution. It also made possible the avoidance of extreme load peaks and made the load curve smooth. MV and LV networks have large number of branches, so these were poor medium compared to the HV overhead lines. As RCS worked in the low frequency range (approximately 125−3000 Hz), the transmission power had to be according to the peak load of the network. Hence, the transmission power was large, in practice it is around 0.1−0.5 % of the maximum apparent power. Here, the applied carrier frequencies enabled the information to flow over transformers between MV and LV networks with less attenuation. Also, the data rates were low and the data transmission was unidirectional as it is from the power supply company to the consumers end. To transmit information through electrical

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CHAPTER TWO LITRETURE REVIEW networks, RCS was used with the Amplitude Shift Keying (ASK- a type of amplitude modulation that assigns bit values to discrete amplitude levels) as well as the Frequency Shift Keying (FSK- a type of frequency modulation that assigns bit values to discrete frequency levels) methods [1].

In 1936, the indirectly heated cathode valve was introduced. In 1947, theinvention of transistor reduced the size of all electrical and electronic devices. The invention of integrated circuits in 1958-59 by Robert Noyce from Fairchild Semiconductor and Jack Kilby from Texas Instruments and later the invention of microprocessor in 1971 by Ted Hoff at Intel launched the development of low cost integrated circuits for power line carrier communications. Also by the late 1980s and the early 1990s, sophisticated error control coding techniques and their implementation into low cost microcontrollers within the hardware of PLC modems were proposed.

The development of modulation methods and the use of higher frequencies in the carrier signal enabled higher data transmission rates and decreased the required transmission power. Also bidirectional data transmission was introduced and the benefits of using power lines for data transmission indoors were implemented along with the introduction of Internet. Several technologies concerned with PLC such as X10, MELKO™, LonWorks, CEBus, INSTEON and HomePlug® were used during the last few decades.

The X10 standard was developed by Pico Electronics in 1975. X10 is an international and open industry standard for communication of electronic devices used for home automation. It mainly uses LV power lines for signaling and control. In this system, the digital data is encoded to a 120 kHz carrier and is transmitted as bursts during zero crossings of AC voltage network. Here, every single bit is transmitted at each zero crossing. Hence, data rates of 100 bps and 120 bps can be obtained in 50 Hz and 60 Hz electric networks respectively.

The next generation devices were based on more effective modulation methods and those provided higher data transfer rates and these were designed for load management in medium and low voltage distribution networks. Here, the transmit power was decreased and it supported bi- directional data transfer. The decrease in transmit power was achieved by increasing the carrier signal’s frequency and using more sophisticated electronic devices. In 1984 the Enermet MELKO™ system was published which utilized the Phase Shift Keying (PSK- a type of angle

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CHAPTER TWO LITRETURE REVIEW modulation in which the phase of the carrier is discretely varied) modulation technique and frequency band between 3025−4825 Hz for data transmission. Here, in MV and LV distribution networks the data transmission rate of 50 bps was possible which were between a substation and measurement or control units. As the frequency band was low and the carrier signal could pass 4

through the distribution transformers, bidirectional data transmission was possible by MELKO™. However, its main applications were remote meter reading and load management.

The members of the Electronic Industries Alliance (EIA) realized the necessity of standards that provides more capability than the X10. Hence, in 1992, they released the consumer electronic bus (CEBus) standard which was also known as EIA-600. CEBus provides protocols to communicate through power lines, twisted pairs, coaxial cables, infrared, RF, and fibre optics. It used spread spectrum modulation technique on power lines within the frequency band of 100−400 kHz. CEBus was a packet-oriented, connectionless and peer-to-peer network which was intended to transmit commands and data. It was mainly suitable for indoor applications.

In 1990, the Local Operation Networks (LonWorks) platform was created by Echelon. It is a flexible, robust and expandable standard based on control networking platform. Here, the physical layer (PHY) signaling can be implemented over twisted pair, power line, fibre optics and radio frequency (RF). The LonWorks provides information based control systems in contrast to the previous command based control systems. The LonWorks PLC technology have data transmission rate of either 3.6 or 5.4 kbps depending on the frequency. Some applications of LonWorks technology are lighting control, energy management, security and home automation systems. The Universal Powerline Bus was introduced in 1999 by PCS Powerline Systems. It is a protocol for communication among the devices used for home automation which uses power line wiring for signaling and control.

In 2001, SmartLabs Inc. introduced a home automation networking technology called INSTEON. It was developed for domestic control and sensing applications and was based on the X10 standard. INSTEON technology is a dual band mesh topology which enables devices to be networked together using power lines or radio frequency. Thereby it is less susceptible to the noise interferences compared other single band networks. Here, PLC uses the frequency of 131.65 kHz and binary phase shift keying (BPSK) modulationG.hn/G.9960 which is a home network

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CHAPTER TWO LITRETURE REVIEW technology standard for high-speed networking over power lines, phone lines and coaxial cables with data rates up to 1 Gbit/s.

Further, in 2008, a standard named IEEE 1675 was developed by Institute of Electrical and Electronics Engineers (IEEE) standards association for broadband over power lines. It provided electric utility authorities or companies a standard for safely installing the required hardware for internet access capabilities over power lines. Subsequently, in 2009, the IEEE P1775 standard concerned with electromagnetic compatibility requirements, testing and measurement methods for powerline communication equipment is being completed by IEEE. Afterward, in 2011, the IEEE 1901 standard is published for high speed (up to 500 Mbit/s) communication devices via electric power lines, hence called broadband over power lines (BPL). The standard uses transmission frequencies below 100 MHz and it is usable by all classes of communication devices including internet access services within a building for local area networks, smart energy applications, transportation platforms (vehicle) and other data distribution applications less than 100m between devices. It includes a mandatory coexistence inter system protocol which prevents interference between different BPL implementations operated within close proximity. Moreover, in September 2011, the standards association of the IEEE published a standard named IEEE 2030 which recognizes the interactive nature of the interconnection with the grid and all of its parts and realizes the significance of the integration of power, communications and information technologies into the smart grid (a modernized electrical grid that uses analogue or digital information and communications technology) with interoperability of energy technology and information technology operation with the electric power system, end-use applications and loads [2].Then, in 2013, IEEE standard association published a standard called IEEE 1905 which defines a network enabler for home networking with support of both wireless and wire-line technologies. For IEEE 1905, the consumer certification program named nVoy was announced in June 2013 and consumer level products were expected by year end 2013 but are delayed till 2014. On the other hand, the Automated Meter Reading (AMR) system was firstly tested by AT&T Corporation (American Telephone and Telegraph Corporation) in cooperation with a group of electric utilities in the USA in 1968. It was a successful experiment and after this AT&T offered to provide AMR service which was based on telephone communication link. However, from economical point of view, this project was non profitable. In 1972, the General Electric (GE)’s corporate research center in

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CHAPTER TWO LITRETURE REVIEW association with its meter department started a research and development attempt for a remote meter reading system. Meanwhile, in 1977, at Rockwell International a utility communication division had been introduced to develop distribution carrier communication systems. Later in 1984, General Electric achieved a license from Rockwell International to commercialize their project of distribution line carrier product designs and technology for AMR.

From 1985, the modern era of AMR started as several full-scale projects of AMR were implemented. Very firstly, the introduction of AMR technology was made by Hackensack Water Corporation and Equitable Gas Corporation into their water and gas measurements systems respectively. Following that, in 1986, the radio based AMR system was installed by Minnegasco for 450,000 customers. Further, in 1987, Philadelphia Electric Co. had installed thousands of distribution line carrier AMR units with the meters which were previously not accessible.

The primary implementation of the automation of meter reading was for reducing labor costs and obtaining data that was difficult to obtain. Because of technical advance in solid-state electronics, microprocessor components and communication sphere, a modern AMR system can provide more useful information which are beneficial for distribution authorities and also enables others additional services which is known as Smart Integrated Metering System. However, the basic idea of remote electricity measurement is common for both AMR and Smart Integrated Metering Systems. Originally AMR devices just collected meter readings electronically and matched them with accounts. As technology has advanced, additional data could then be captured, stored and transmitted to the main computer and often the metering devices could be controlled remotely. This can include events alarms such as tamper, leak detection, low battery or reverse flow. Many AMR devices can also capture interval data and log meter events. The logged data can be used to collect or control the time of use or rate of use and that data can be used for energy or water usage profiling, time of use billing, demand forecasting, demand response, rate of flow recording, leak detection, flow monitoring, water and energy conservation enforcement, remote shutoff, etc. Advanced Metering Infrastructure (AMI) represents the networking technology of fixed network meter systems that go beyond AMR into remote utility management. The meters in an AMI system are often referred to as Smart Meters, since they often can use the collected data based on programmed logic.

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CHAPTER TWO LITRETURE REVIEW

In 2003, in Europe, the Northern Europe became the hotspot of Advanced Metering when Sweden announced the decision to acquire monthly readings of all electricity meters by 2009. Soon activities spread to the other Nordic countries like Finland, Denmark and Norway. In 2004, the Essential Service Commission of Victoria, Australia has brought corrections to the electricity customer metering code to implement an order in the installation of interval electronic meters for Victorian electricity customers. According to the paper entitled "Mandatory Rollout of Interval Meters for Electricity Customers" for all small businesses and residences, the meters have to be installed by 2013, starting from the year 2006. It forecasts that, within seven years from the beginning of the replacing, up to one million large and other customers will have upgraded meters. However, by mid July 2013, the first Smart Meter in home displays was being made available to Victorian consumers. At the beginning of 2014, over 2.5 million meters installed at homes and small businesses across the state.

The United States (US) energy policy act of 2005 asked the electric utility regulators to consider time-based rate schedule and enable the electric consumer to manage the energy use and cost through advance metering and communication technology. Besides, in November 2005, the Meridian Energy in New Zealand introduced the usage of smart meters in the Central Hawkes Bay area for over 1000 households. The communication link was based on radio andmobile technologies. It was expected to install over 6,300 smart meters by late 2006 as part of the initiated experiment. In Italy, the world's largest smart meter deployment was undertaken by Enel SpA for more than 30 million customers. Between 2000 and 2005, Enel SpA deployed smart meters to its entire customer base. These meters are fully electronic and smart, with integrated bi-directional communications, advanced power measurement and management capabilities with solid-state design.

The Commonwealth issued a joint communiqué at the council of Australian Governments meeting in Canberra in February 2006, committing all governments to the progressive rollout of smart metering technology from 2007. In September 2006, the Netherlands government conducted a cost benefit analysis of AMR for their country and proposed that all residential customers will get a smart meter by the year 2013, starting from 2008. Since then, two utilities named Continuon and Oxxio have been undertaking some pilot projects for the implementation of AMR. The smart meter’s register electricity and communicate through PLC.

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CHAPTER TWO LITRETURE REVIEW

In February 2007, the Automatic Meter Reading Association (AMRA) endorses the National Association of Regulatory Utility Commissioners (NARUC) resolution to eliminate regulatory barriers to the broad implementation of Advanced Metering Infrastructure (AMI). The resolution passed acknowledged the role of AMI in dynamic cost savings in revenue protection, outage management and its benefits to the consumers. In June 2007, the Norwegian energy authority declared that it would recommend new legislation for requiring smart meters to take effect in 2013. Also in 2007, the Republic of Ireland pledged to introduce smart meters in every home within a five-year period. In December 2007, the smart metering was included in the national meter substitution plan of Spain for end users with an aim of remote energy management with a deadline for the completion of the plan by 31st December, 2018. The Ontario Energy Board in Ontario, Canada set a target of deploying smart meters to 800,000 homes and small businesses by the end of 2007, which was surpassed, and throughout the province by the end of 2010In July 2008, from government of Australia the Advanced Metering Infrastructure was mandated and being planned in Victoria for deployment of 2.6 million meters over a four-year period. Also in 2008, Austin Energy of Texas, United States began deploying approximately 260,000 residential smart meters. According to the report from VaasaETT of October 2008, an energy think tank in Helsinki, Finland found that smart meters are saving energy by around 10%. At the end of 2008, the installed base of smart meters in Europe was about 39 million units, according to the analyst firm Berg Insight.

In 2009, Florida Power and Light in United States began installing smart meters in the Miami-Dade area for residential customers and it’s expected to be completed by 2013. In October 2009, the U.S. Department of Energy awarded $200 million grant for the deployment of CenterPoint Energy's smart meter network in Texas. In December 2009, the United Kingdom's Department of Energy announced its intention to have smart meters in all homes by 2020. Here, the principal media of communication in the Home Area Network is ZigBee Smart Energy. ZigBee is a specification for a suite of high level communication protocols used to create personal area networks built from small, low power digital radios.

In January 2010, it was estimated to install 170,000 domestic smart meters in United Kingdom and in October 2010, First Utility became the first energy supplier to offer smart meters to all new and existing customers across the U.K. A smart metering pilot project named Linky was

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CHAPTER TWO LITRETURE REVIEW conducted by Electricité Réseau Distribution, France involving 300,000 clients supplied by 7,000 low-voltage transformers. The experimentation phase started in March 2010. A key determining factor will be the interoperability of the equipment of various suppliers. The general deployment phase will start in 2016 and continue through 2020.

In January 2011, the American Council for an Energy-Efficient Economy reviewed more than 36 different residential smart metering and feedback systems internationally. Their conclusion was “To realize potential feedback induced savings, advanced meters must be used in conjunction with in home displays and well-designed programs that successfully inform, engage, empower and motivate people." In United States, Texas based CPS Energy has launched a pilot program with 40,000 smart meters deployed in the summer of 2011. CPS plans to complete the installation of smart meters (electricity and gas) for all customers by the end of 2016.

The United Kingdom rollout is considered to be the largest program involving more than 27 million homes to replace meters for both gas and electricity. The rollout officially started in 2012 but some energy suppliers started installing smart meters in people's homes before this. Besides, in spring 2012, Baltimore Gas and Electric of Maryland, United States began installing or upgrading approximately two million electric and gas meters in every home and small business in their service area. This process will take about three years to complete. These smart meters help customers to manage their energy budgeting, tracking and save money. By July 2013, the first Smart Meter in home displays was made available to Victorian consumers of Australia. At the beginning of 2014 Smart Meter in home displays were spreading rapidly. By the end of 2014, in United Kingdom the full rollout with the data communications for domestic customers are almost completed. Most households will have smart meters installed by their energy providing company/authority between 2015 and 2020, although some energy companies are starting to install smart meters already.

2.2 PLC applications: 2.2.1 according to the frequency: In accordance with the application, the axis is divided into three portions. Any portion is suitable for some specific applications. The broadband PLC uses the frequency band between

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CHAPTER TWO LITRETURE REVIEW

1MHz and 300MHz. It is suitable for high data rate transmission, more than 10Mbps. The NBPLC’s portion uses the CENELEC bands for low data rate transmission, less than 50kbps. Over the frequencies from 145.3kHz to 500kHz, the NBPLC’s technologies are used to perform high data rate transmission between 50 kbps and 1 Mbps. Thereby, the applications of the power line communications technology are related to the frequency band used. The applications of BBPLC cannot be deployed over NBPLC frequencies. The deployment of the technology over each range of frequencies is supported by many companies and organizations. Table (2-1) gives some specifications on the application of the power line communications technology. It shows the frequency band, some modulation schemes proposed by the SDOs for both NBPLC and BBPLC. The complexity of the forward error correction (FEC), the access method and some companies and organizations supporting the standards are also mentioned. The NBPLC frequency bands are used for metering, lighting, energy and grid management.

The BBPLC frequency band is used for applications such as last mile telecom, voice over IP and high definition television. Companies such as Gorlitz and alliances such as G3-PLC, PRIME are specialized in meter manufacturing. The KNX organization is the standard for home and building control.

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CHAPTER TWO LITRETURE REVIEW

Table 2-1: Applications of PLC

UNBPLC NBPLC BBPLC

Frequency 3~148.5 KHz 145.3~478.125 KHz 1~300 MHz

FSK, BPSK, FFH (Fast DBPSK, DQPSK, MCM/COFDM Bit Frequency Hopping), OFDM, MCM loading Modulation and SFSK (dual ch/spread (Multiple carrier Coding FSK), DCSK diff chrip modulation) shift keying

FEC Low complexity and Strong, hirgh Medium Maximum reliability reliability design throughput

Access CSMA/CA, TDMA CSMA/CA, TDMA CSMA/CA, TDMA

Transport layer IPv6, IPv4, Ethernet IPv6, IPv4, Ethernet IPv6, IPv4, Ethernet

Applications Automatic meter AMR, Airfield lighting, Last Mile Telecom Power line area network Energy (LMT), Internet, management, Smart VoIP, IH networking, Grid application and High definition TV metering, ARM (HD TV)

2.2.2 According to the voltage: The applications are very wide and we can divide them into two categories: The Medium Voltage or access technology mainly used by the utility authority, the Low Voltage or in home

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CHAPTER TWO LITRETURE REVIEW which cover the area of sending data over power lines within the consumer’s side and extends to all the electrical outlets within the home.

2.2.2.1 Low voltage or in-house: 2.2.2.1.1 Home automation: Many years ago control of appliances in the home used to call for the establishment of new cable wiring in the home. With the DTOPL technology automation of a building can be done using power lines only. Hence we can control home appliances, light switches, wall outlets, thermostats, Heat Ventilation and Air Conditioning systems (HVAC), sensors, alarm and security. One of our project goals is to implement the home automation.

2.2.2.1.2 Street lightening monitoring: The use of DTOPL to monitor street lights leads to big savings in the electricity bill of the government by introducing selective dimming or selective turn-off features. This application can increase energy savings by 25%.

2.2.2.1.3 Low cost inter-device peer-to-peer networking: Power lines may be used to create a network that links devices together on the power grid. Since such a network makes use of the existing infrastructure, installation time and cost are virtually non-existent. Also since every outlet or junction box becomes a point where a device may be connected, the device can be moved around numerous times. An example of such a network can be to replace the RS232 wiring required to set audio and video inputs on various systems in a house or a building.

2.2.2.2 Medium Voltage and Low Voltage: 2.2.2.2.1 Utility:

 Automatic Meter Reading is a technology that uses the power line to send information to the utility directly. Meters can be linked to concentrators to allow suppliers to have remote access to each individual meter, to read or write information such as rates, pre-paid amounts, current and cumulative counts, tampering detection, etc. Meters and/or concentrators can also be used along

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with AC Remote LCD devices to replicate and distribute their information to one or more points located anywhere on the electrical network.

 Load shedding: this is done when we need to reduce power given to loads when we have peak demands hours. As an example incandescent lights, with the help of a load control circuit will receive less power when the utility notices that the demand for electricity is at its peak in certain periods.

2.2.2.2.2 Broadband data transmission: This developing technology which is at its testing level (Italy, USA) nowadays enables broadband internet to be provided to your home using the electrical grid. This feature is behind the scope of our project however we will give a brief overview of what this technology is about:

An example of a company developing this technology is ABB Medium Voltage Power Solution. This system certified for use up to 24 KV provides data transfer rates of up to 10 Mbps and hence challenging the xDSL and the broadband cable technology. The main problem in this technology is the connection between the MV and the LV grid which is done using optical fibers, copper pairs or wireless[3].[4].

2.3 PLC Types Power Line Communication (PLC) which uses power cable as communication media has received attention as a candidate communication technology for smart power system. PLC is not a new technology. Utility companies have used PLC for metering and control of applications for several decades. PLC which has been used for this purpose has few bps of data rate and used a narrow band frequency. PLC is only a wire technology which can compete with wireless technologies economically because cost for cable deployment is not necessary. Also PLC can support ubiquitous solution with distributed power grid. PLC can be classified in three types through the use of frequency band. Table 2.1 shows summary of these three types of PLC.

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CHAPTER TWO LITRETURE REVIEW

Table 2-2: PLC Classifications

Classification Frequency band Data rate Applications

Ultra-Narrowband ~3 KHz Hundreds bps Control, AMR PLC

(UNB-PLC)

Narrowband PLC 3~500 KHz 10s ~ 500 kbps Control, Smart metering (NB-PLC)

Broadband PLC 1.8~250 MHz Over 1 Mbps Data, Multimedia Communication.

2.3.1 Ultra-narrow band plc Ultra-Narrowband Power Line Communication (UNB-PLC) is operated at a frequency band of below 3kHz. The data rate of UNB-PLC is very low (hundreds bps), however, the communication range is over 150 km. UNB-PLC has been used for automation for distributed facilities and Automatic Meter Reading (AMR) solution for several decades. Though it has many advantages such as maturity of technology, cost and communication range, the usage of UNB- PLC has been restricted field due to a low data rate. UNB-PLC can be a good candidate technology for WAN just considering its operating range. UNBPLC may not be considered for communication Infrastructure of Micro Grid because Micro Grid covers only a small area.

The earliest PLC systems are ripple control systems, first introduced in the 1930s, and still used in parts of Europe and New Zealand to provide basic low bandwidth direct load control and other telemetry. These use basic modulation schemes on a lower frequency carrier to convey information.

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Another approach used since the 1970s leverages the fundamental alternating current (AC) frequency (50-60 Hz) as a carrier to transmit information on the power line. As a result, these systems avoid many of the noise and attenuation issues of other PLC technologies (which impose other carrier frequencies) and can be transmitted across long distances and through transformers without repeaters. The leading example of this is Two-Way Automatic Communications System (TWACS – today known as Aclara PLC). These systems also deliver 10 to 100 bits per second data rates.

Low-speed PLC systems have been widely deployed for remote meter reading and direct load control applications.

2.3.2 Narrowband plc Narrowband Power Line Communication (NB-PLC) uses 3 ~ 500Khz frequency band and supports several hundred bps of data rate. Industry and academia have paid attention to the technology of NB-PLC recently. PLC has a harsh channel circumstance like that of a wireless communication and it also has a problem of electromagnetic compatibility (EMC). Using a wide frequency band can increase the data rate of PLC which is called Broadband PLC but many concerns like interference, attenuation and frequency regulation should be considered to support a robust communication services. Using narrow frequency band can release the mentioned problems although NB-PLC has a low data rate. For this reason, NB-PLC has got more attention comparing with PLC using wide frequency band nowadays. The frequency band for NB-PLC is shown in Table 2-2. These rates are appropriate for telemetry and control applications. In North America, Japan and China, the frequency range of up to 500 kHz are viable under local regulations for N- PLC and offers a reasonably wide communications bandwidth (up to above 300Kbps) and a broader range of applications can be considered. There are many different implementations, with varying data rates, modulation schemes, and degrees of adherence.

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Table 2-3: Frequency band for NB-PLC

Region Institution Frequency

CENELEC A: 3~95 KHz

(European Committee for B: 95~125 KHz Electro-technical Europe Standardization) C: 125~140 KHz

D: 140~148.5 KHz

FCC 10~490 KHz

USA (Federal Communications Commission)

ARRIB 10~450 KHz

Japan (association of Radio Industries and Business)

PRIME (Powerline Related Intelligent Metering Evolution), an OFDB based NB-PLC specification which started from 2007 uses CENELEC A frequency band and supports 125 kbps of data rate. G3-PLC which was released at 2009 is also an OFDM based NB-PLC specification with frequency band from 10 to 490KHz. The maximum data rate of G3-PLC is 46 kbps. Though both specification uses OFDM with DPSK modulation, the PRIME is originally designed for Metering through LV (Low Voltage) power grid and G3-PLC is designed for smart grid considering MV (Medium voltage) power grid and transformer which has a high noise and attenuation. Therefore, G3-PLC has a lower data rate compared with PRIME, however, G3-PLC has a higher robustness. Standardization for NBPLC has been started from 2010. IEEE1901.2 and ITU-T G.hnem have been designed for applications for smart grid. Both standards support

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CHAPTER TWO LITRETURE REVIEW communication through LV power cable, MV power cable and transformers with up to 500 kbps data rate. NB-PLC with LV and MV power cable may be great candidates for communication technology for the NAN in Micro Grid.

2.3.3 Broadband plc Broadband Power Line Communication (BB-PLC) is a technology for high speed data communication with a frequency range of 1.8 MHz ~ 250 MHz. In the early 2000, several industrial specifications of BB-PLC especially for home network & video transmission have been released. These industrial specifications are explained at Table 2-3.

BPL technologies generally operate at carrier frequencies well above the CENELEC bands and therefore experience inconsistent and extremely challenging spectrum characteristics. Not only has reliable communications been hard to achieve, but these systems have also caused significant electromagnetic interference problems.

All three BB-PLC specifications use CSMA/CA MAC (Medium Access Control) scheme and support around 200Mbps physical throughput. All these specifications have been designed for HAN. These three industrial specifications have many similar aspects, however, they do not support interoperability. Recently released BB-PLC specification HomePlug AV2 supports up to 1Gbps transmission rate with MIMO. In 2010 IEEE1901 standard for BB-PLC has been released. IEEE1901 supports two modes of BB-PLC. One is OFDM based PHY/MAC scheme which is compatible with HomePlug AV specification and the other is wavelet OFDM based PHY/MAC scheme compatible with HD-PLC specification. IEEE1901 standard also can get up to 200 Mbps physical throughput. ITU-T also released ITU-T G.hn standard for home networking. ITU-T G.hn is standard for all wired communication technologies for homes such as Power line (PLC), Phone line and coaxial cable with up to 1 Gbps bit rate. BB-PLC can support high data rate for data communication but transmission range is limited (around 100m). Therefore, BB-PLC can be a great technology for HAN however to use for NAN, the help of other facilities like a repeater may be necessary.[5]

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CHAPTER TWO LITRETURE REVIEW

Table 2-4: Industrial specification of BB-PLC

Alliance Frequency Throughput Modulation Chip set Band Maker

HomePlug 1.8 ~ 30 200 Mbps OFDM Intellon MHz (Qualcomm) (Homeplug Power Line Alliance)

UPA 3~33 MHz 200 Mbps OFDM DS2 (Marvell) (Universal Powerline Association)

HD-PLC 2~28 MHz 210 Mbps Wavelet Panasonic OFDM (High Definition Powerline Communication)

2.4 Plc standards When using the powerline as a channel certain standards and regulations must be followed in order to avoid interference between the frequencies transmitted with any other frequencies already existing. Hence the bandwidth in the DTOPL environment is not limited by physical capabilities of the line. Rather, regulatory authorities in the developed countries limit the available bandwidth in order to prevent radio interference, other devices interference or military bandwidth interference. The standards in power line communications (PLC) calibrate

parameters such as frequencies allocation, signal level, security, topology of the

network and many others parameters. In power line communications

(PLC), the SDOs focus on the physical (PHY) and on the data link (DLL) layers as shown on Fig (2.1). The other layers are reserved for the application.

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CHAPTER TWO LITRETURE REVIEW

Figure 2.1: PLC system layers

Here we will discuss the limiting standards CENELEC, FCC, IEEE and IEC governing data transmission over power lines.

2.4.1 CENELEC For Western Europe CENELEC’s standard EN50065 [6] “Low voltage mains signaling” gives regulations on key parameters such as frequency range, signal power and so on. The standard allows signals to operate in the frequency band 3- 148.5kHz, avoiding interference with ripple control systems at the lower boundary, and interference with long wave (LW) and medium wave (MW) radio broadcasts by posting the upper boundary. CENELEC then divide this band into further categories:

• A-band (3 kHz - 95 kHz)

• B-band (95 kHz - 125 kHz)

• C-band (125 kHz - 140 kHz)

• D-band (140 kHz - 148.5 kHz)

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CHAPTER TWO LITRETURE REVIEW

We can see frequency ranges and maximum transmission levels for power line communication according to CENELEC 50065-1 standard

Table 2-5: CENELEC categories

Band Frequency range Maximum Usage areas transmission level

A 3khz -95 khz 134db (μV) Available for electric distribution companies use only

B 95khz - 116db (μV) - Available for consumers with no 125khz 134db (μV) restriction

C 125khz - 116db (μV) - Available for consumes only with media 140khz 134db (μV) access protocol

D 140khz - 116db (μV) - Available for consumers with no 148.5khz 134db (μV) restriction

2.4.2 FCC For North America the Federal Communications Commission (FCC) regulates transmitted power and bandwidth. The frequency range in this standard is from 100 to 450 KHz which is higher than the CENELEC. Moreover, Part 15 of the American FCC’s rule allows transmission over power lines outside the AM frequency band (535 to 1705 KHz).

2.4.3 IEEE The Institute of Electrical and Electronics Engineers [8] have published a set of recommendations and standards pertaining to the power line communication available at the reference: http:://standards.ieee.org/catalog/olis/psystcomm.html.

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CHAPTER TWO LITRETURE REVIEW

2.4.4 IEC The International Electrotechnical Commission (IEC) [9] has standardized the distribution line communications through technical committee #57 working group 9. In this standard, IEC TC57/WG9 uses frequencies below 150 KHz.

IEC 61334, known as Distribution automation using distribution line carrier systems, is a standard for low-speed reliable power line communications by electricity meters, water meters and SCADA. It is actually a series of standards describing the researched physical environment of power lines, a well-adapted physical layer, a workable low-power media access layer, and a management interface.

G3-PLC, Powerline, intelligent metering evolution (PRIME), the American national standards institute (ANSI), KNX and HOMEPLUG are some groups and alliances that develop and deploy standards and technologies in power line communications sector.

The HomePlug Alliance is an association of companies within the electric utility industry in the United States. The companies include Cogency, Panasonic, Radio Shack Corp. and Sharp.

Twenty participating member companies accompany this group and some of the big players include Motorola, Philips Electronics, Sony Corp. and France Telecom. The HomePlug Alliance developed the HomePlug standard and they meet the current FCC Part 15 requirements for current carrier systems. The aim of the HomePlug standard is to provide interoperability between consumer devices by setting a MAC protocol as well as the physical signaling techniques to be used a form of orthogonal frequency division multiplexing (OFDM) modulation using up to 76 carriers in the band 4.5 MHz to 21 MHz. The throughput rate of a typical HomePlug standard is 14 Mbps with extrapolated rates going up to 20 Mbps. G3-PLC, PRIME, ANSI and KNX propose technologies using the CENELEC’s frequency bands. G3-PLC works on the range between 35kHz–90 kHz while PRIME alliance uses the frequency band 42 kHz–90 kHz. ANSI proposes technologies for the frequencies from 86 kHz–131 kHz and KNX works with the band of frequencies between 125 kHz to 140 kHz. HomePlug is present over the whole PLC’s frequency band.[3][6]

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CHAPTER TWO LITRETURE REVIEW

2.5 PLC protocols and Technologies The technologies and standards used presently in the Power Line Communications are investigated in depth. These include LonWorks, X-10, OFDM, Passport CEBus and the HomePlug standard. Then focus was on the technologies that are being deployed based on the standards. The advantages and benefits of using Power Line as the medium of data transmission at homes was also considered. The quality of service, data transmission rates, the limitations, the drawbacks and other important factors were taken into account. The description of technologies follows.

2.5.1 X-10 It is the most ancient communication protocol used in home networking since 1978 developed by X-10 US Corporation. It is used to allow compatible devices to communicate with each other over 110V AC wiring.

2.5.1.1 Protocol description X-10 simply provides the technical specifications of how a device should place a signal onto the power line. The X-10 technology transmits binary data using the amplitude modulation technique. In order to differentiate the data symbols the carrier uses the zero voltage crossing point of the 60 Hz on the negative or positive cycle.

Hence for synchronization, the presence of a 120 kHz signal burst at the zero crossing indicates the transmission of a binary one, whilst the absence of the 120 kHz signal indicates a binary zero.

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CHAPTER TWO LITRETURE REVIEW

X-10 Figure 2.2: Representation of the X-10 signal contains a detailed addressing scheme to prevent device clash. Devices contain two addresses - a house (dwelling) address, and then an individual device address. A typical X-10 transmission would include a start code, house address, device address, and then function code (such as ON, OFF, etc.). The X-10 system is limited in that it does not easily provide for two-way communications, and is very slow, although adequate for simple home automation tasks. Every bit requires a full 60 Hertz cycle and thus the X-10 transmission rate is limited to only 60 bps. Usually a complete X-10 command consists of two packets with a 3-cycle gap between each packet. Each packet contains two identical messages of 11 bits (or 11 cycles) each. A complete X-10 command consumes 47 cycles that yield a transmission time of about 0.8.

Figure 2.3: tow packet of the X-10 protocol.

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CHAPTER TWO LITRETURE REVIEW

2.5.1.2 Disadvantages The X-10 technology would not fit our project design for the main fact that it has limited potential in speed and intelligence terms. Its low data rate and undeveloped functionality permit to use the X-10 technology in limited applications. In addition to its unreliability of amplitude modulation and error correction, X-10 operates on 110V AC, which is a major drawback for its use.

2.5.2 CsBus technology CEBus, or Consumer Electronics Bus, a standard proposed by the Electronic Industries Association, is based on the concept of Local Area Networks (LAN’s), for the home. CEBus based products consist mainly of two components: a transceiver which implements spread spectrum technology along with a controller to run the protocol. The given protocol standards are for radio frequency, twisted pair, power line communication and a number of other home networking methods. The CEBus DTOPL standard specifies that a binary digit is represented by how long a frequency burst is applied to the channel. For example, a binary ‘1’ is represented by a 100 microsecond burst, whilst a binary ‘0’ is represented by a 200 microsecond burst. Consequently, the CEBus transmission rate varies with how many ‘0’ characters, and how many ‘1’ characters are transmitted. The CEBus standard specifies a language of object oriented controls including commands for volume up/down, temperature up one degree, etc. Due to the high noise level of power line channels, data should be transmitted via short frames, which is assured by the use of the spread spectrum technology. CEBus protocol uses a Carrier Sense Multiple Access/Collision Detection and Resolution (CSMA/CDCR) protocol to avoid data collisions. CEBus is a commercially owned protocol, and thus attracts registration fees.

2.5.3 LonWorks technology This technology has been developed by Echelon Corporation [4]. It is essentially structured as an automatic control system that consists of sensors, actuators, application programs, communication networks, human-machine interface and network management tools. LonWorks (Local Operation Networks) technology is an important new solution for control networks

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CHAPTER TWO LITRETURE REVIEW developed by Echelon ® Corporation. A control network is any group of devices working in a peer-to-peer fashion to monitor the different components cited above. In some ways, a LONWORKS control network resembles LAN. It can control and link factory conveyor belts, product inventory, and distribution systems for optimum efficiency and flexibility. Smart office buildings can turn lights on and off, open and lock doors, start and stop elevators, and connect all functions to a central security system. In the same manner, homeowners can program a vast array of products and conveniences, from sprinkler systems to VCRs, with a touch tone phone from any remote location. The LonTalk communications protocol is a layered, packet-based, serial peer-to- peer communications protocol. This protocol is designed for the requirements of control systems, rather than data processing systems. Also, this protocol is media-independent, which allows the system to communicate over any physical transport media. LonTalk has been approved as an open industry standard by the American National Standards Institute (ANSI)-EIA 709.1.[7][6]

2.6 PLC system components Plc system main components can be classified as:

 Plc modem

 Coupling circuit

 Power supply

 Controller

2.6.1 Modem Modulation is process for moving a signal in a transmission medium via a high frequency periodic signal. High frequency signal called carrier frequency [1]. Data signal can change of carrier frequency’s amplitude, frequency or phase values. Here we are going to discuss only digital modulation techniques:

2.6.1.1 Amplitude shift keying ASK At amplitude shift keying, every bits changes the carrier signal’s amplitude. If the data bit is logic “1” then output is equal to carrier signal otherwise output is zero. ASK is so sensitive for

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CHAPTER TWO LITRETURE REVIEW noise and propagation conditions. ASK is inexpensive and simple modulation type than other modulation types. This modulation is shown in figure (2.4).

Figure 2.4: Amplitude Shift Keying

2.6.1.2 Phase Shift Keying At phase shift keying, the data bits change the carrier signal’s phase. Generally, PSK uses two different angles for communication. For instance, if the data signal’s bit digital “0” output sinusoidal wave’s phase angle 0º and for digital “1” phase angle 180º. So two different angles can transmit 1 bit and four or more angle can transmit 2 or more bit at 1-cycle. Quadrature Phase-Shift Keying (QPSK) uses four phase and QPSK is the most known PSK type. Bluetooth, wireless modems, satellite TV receivers and RFID cards uses advanced PSK types. This modulation is shown in Figure (2.5).

Figure 2.5: Phase Shift Keying

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CHAPTER TWO LITRETURE REVIEW

2.6.1.3 Orthogonal Frequency Division Multiplexing (OFDM) modulation techniques transmit data via a series of parallel subcarriers set at different frequencies. In theory they allow high-bandwidth levels, but in practice a great deal of bandwidth is lost under noisy conditions over low-voltage networks. On top of that, OFDM can prove costly to implement and draws significant power to operate.

2.6.1.4 Frequency Shift Keying At frequency shift keying, the data signal’s every bit changes the carrier signal’s frequency. FSK has many application areas in our daily-life (e.g. radio, modem, fax). FSK is very immune to noise. Because noise can change the signals amplitude but it can’t change the signals frequency easily. Particularly resilient to narrowband interference, Spread-Frequency Shift Keying (S-FSK) modulation as described by IEC 61334 transmits data through discrete frequency changes in the carrier wave. Though it supports lower data rates than OFDM, these rates are still more than sufficient for smart metering applications. This modulation technique is capable of robust communication, as well as being cheaper to implement and drawing limited power.

On this basis it seems that S-FSK, with its lack of complexity, greater commercial viability, and reliable track record in the field, is destined to see greater first-phase PLC deployment than the alternative modulation options. In this project FSK is used in transmitter side.

Therefore, at the receiver, we have to recover the FSK signal to digital signal, that means the frequency should be converted back to voltage. We use phase locked loop (PLL) as FSK demodulator. PLL is a kind of automatic tracking system, which is able to detect the input signal frequency and phase. PLL is widely used in wireless applications, such as AM demodulator, FM demodulator, frequency selector and so on. In the digital communications, various types of digital PLLs are developed. Digital PLL is very useful in carrier synchronization, bit synchronization and digital demodulation. In figure, when the input signal frequency changes, the output signal of the phase detector will change and so as well as the output voltage. We can use this characteristic to design the

FSK demodulator. Let the FSK signal frequencies as f1 and f2, then these signals are inputted to the

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CHAPTER TWO LITRETURE REVIEW

input terminal of figure. When the input signal frequency is f1, the output voltage will be V1. When the input signal frequency is f2, the output voltage is V2. At this moment, we have converted the frequency to voltage. If we add a comparator at the output terminal of PLL, the reference voltage will lie between

V1 and V2, then at the output terminal of comparator, we are able to obtain the digital signal, which is the demodulated FSK signal.[8]

2.6.2 Coupling circuit The biggest technical challenge in a power line carrier is to couple the low voltage and high frequency carrier set to the high voltage and low frequency power line. The carrier signal is injected on the power line through the coupling network.

There are two methods of connecting the power line communication module into the network:

Capacitive Coupling: A capacitor is responsible for the actual coupling and the signal is modulated onto the network’s voltage waveform.

Inductive Coupling: An inductor is used to couple the signal onto the network’s current waveform. Inductive coupling some time is rather noisy, however, the advantage is, no physical connection to the network has to be made. Thus make it safer to install as compare to capacitive coupling.

When designing the coupling circuit, two major types of components as described in the table below should be considered. Another important feature to take notes is the protective coupler circuitry.[9] [10]

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CHAPTER THREE METHODOLOGY AND DESIGN

3 CHAPTER THREE: METHODOLOGY AND DESIGN

This chapter present design and development process to come up with our plc final system.

3.1 Design goals We aimed to design a system that transmit digital data from the sender to the receiver using power lines as communication channel. The transmission system has to convert the information data in a suitable form before it is injected in the communication channel. There are several multiplex and modulation schemes which are investigated to be applied in the PLC transmission systems. The frequency of the carrier signal should be much higher than the frequency of the 220 V signal (50Hz) to avoid the interference between these two signals. PLC circuit must be insulated from power line, which is very important for human health and for the operation of the circuit. For this purpose, a coupling circuit must be designed to inject the modulated signal into the power line and block the AC mains signal preventing it from reaching the input of modem communication system.

On the other side, the modulated signal must be extracted from the power line using the coupling circuit. The receiver must recover the digital data from the modulated signal through applying one of the demodulation techniques.

Transceiver system must include filters to avoid the noise and attenuation caused by using power lines as communication channel.

3.2 System components 3.2.1 PLC Transmitter Our transmitter consists of a chip that modulate the digital signal using FSK modulation technique. Generating FSK signal can be done by different types of chips after investigation and number of experiments (555 timer, multiplexer, XR-2200, LM566) LM566 VCO was used .

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CHAPTER THREE METHODOLOGY AND DESIGN transmitter. Also contains filters and amplifiers to amplify the small modulated signal that produced by the chip.

3.2.2 PLC receiver The circuit consist of many filters to block the noise and amplifiers to amplify the modulated signal after propagating through the power line.

3.2.3 Coupling circuit We use a simple coupling circuit. That consist of a coupling capacitor and transformer.

3.2.4 Decoupling circuit It is the same as the coupling circuit but at the receiver.

3.2.5 Power lines The communication channel that we used to transmit the data.

Figure 3.1: Blocks of system components

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CHAPTER THREE METHODOLOGY AND DESIGN

3.3 Tools and instruments 3.3.1 Software tools 3.3.1.1 Proteus 8.6 Was used to simulate the actual circuit.

Figure 3.2: proteus 8.6

3.3.2 Hardware 3.3.2.1 Oscilloscope We used it to monitor the output from the modulation and demodulation circuits.

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CHAPTER THREE METHODOLOGY AND DESIGN

Figure 3.3: oscilloscope

3.3.2.2 Function generator In one of our experiments we use function generator to produce two signals with different two frequencies.

Figure 3.4: Function generator

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CHAPTER THREE METHODOLOGY AND DESIGN

3.3.2.3 Breadboard a construction base for prototyping of electronic circuits.

Figure 3.5: Breadboard

3.3.2.4 Cpacitors and resistors

Figure 3.6: capacitors Figure 3.7: Resistors

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CHAPTER THREE METHODOLOGY AND DESIGN

3.3.2.5 NPN transistors

3.3.2.6 Opamps Figure 3.8: NPN transistor

3.3.2.7 VCO (lm566) Voltage controlled oscillator used to modulate the digital data using FSK modulation technique.

Figure 3.9: VCO LM566

3.3.2.8 PLL 3.3.2.9 Timer 555

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CHAPTER THREE METHODOLOGY AND DESIGN

3.4 System design steps 3.4.1 Step one: Generation of FSK signal Signal has to be modulated before transmission, and one of the methods is the frequency- shift keying (FSK) modulation. FSK technique is to modulate the data signal to two different frequencies to achieve effective transmission. At the receiver, the data signal will be recovered based on the two different frequencies of the received signal.

Figure 3.10 shows the relationship between the FSK signal and the data signal.

Figure 3.10: FSK signal and data signal

The technique of FSK is widely used in commercial and industrial wire transmission and wireless transmission.

For wire transmission such as telephone, the frequencies are as follow:

Space = 1370 Hz, Mark = 870 Hz Or Space = 2225 Hz, Mark = 2025 Hz

We obtained the FSK signal by using three methods. The first and the simplest way is to use multiplexer. The second method by using 555 timer. Finally, we have used LM565 voltage controlled oscillator to get the required signal with the specified frequency.[11]

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CHAPTER THREE METHODOLOGY AND DESIGN

3.4.1.1 Design 1: Using Multiplexer Two function generators are used. They produce two signals with different frequencies (mark and space frequencies). Each generator is connected to one of the multiplexer inputs. The digital data is connected as selecting signal.

This experiment was done in proteus simulation. Figure 3.11 illustrate the simulation components. Which consist of a multiplexor and two function generators.

Figure 3.11: Multiplexor circuit

3.4.1.2 Design 2: Using 555 timer The output frequency of the signal was based on the input digital signal given to the base of the transistor. When the given input was high that is of logic 1 the PNP transistor was Q is off and IC 555 timer works in the normal mode of operation giving out the series of square wave pulses thus there will be no change in the frequency of the output signal. Here the resistors Ra, Rb

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CHAPTER THREE METHODOLOGY AND DESIGN and Capacitor C was selected in such a way to obtain output frequency. The output frequency when the input was high was given by the equation:

Equation 1 1.45 푓 = 푅푎 + 2푅푏

When the input binary data if logic 0, the PNP transistor is on and its connects the resistance Rc across resistance Ra. The resistors Rc is selected in such a way that the value of 1space frequency. Here the value of Rc added in addition to the Ra, Rb and C to contribute the working of the NE555.This makes the charging and discharging quicker resulting in high frequency waves as output. The Ra, Rb, Rc and C values was selected in such a way to obtain output of space frequency. This was given by the equation:

Equation 2 1.45 푓 = ((푅푎||푅푐) + 2푅푏)퐶

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CHAPTER THREE METHODOLOGY AND DESIGN

Figure (3.12) shows the simulation of the circuit using proteus 8.6.

Figure 3.12: 555 timer simulation

After simulation step actual circuit implementation was done as shown in figure (3.13).

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CHAPTER THREE METHODOLOGY AND DESIGN

Figure 3.13: Real Circuit

3.4.1.3 Design three: using Voltage Controlled oscillator (VCO) LM566 The two frequencies can be produced by using a Voltage Controlled Oscillator (VCO). The output signal frequencies are varied by the difference levels of the input pulse to produce two different frequencies. Each output signal frequency corresponds to an input voltage level (i.e. "0" or "1").

The oscillation frequency of LM566 is:

Equation 3

2 푉퐶퐶 − 푉퐼푁 푓0 = ( ) 푅10퐶5 푉퐶퐶

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CHAPTER THREE METHODOLOGY AND DESIGN

Where Vcc is the power supply voltage input at pin 8 of LM566. Vin is the input voltage of LM566 at pin 5.

The simulation for our circuit is illustrated at figure (3.14). First we have to convert the voltage level of data signal to appropriate voltage level that will be the LM566 input. According to the input voltage level the VCO will produce the frequency.

In this circuit, Q2 will operate as NOT gate. When the input signal of the base of Q2 is high, then Q2 will switch on. At this moment, the output signal of the collector will be low (around 0.2 V), so Q1 will switch off. When input signal of the base of Q2 is low (0 V), Q2 will switch off. At this moment, the output signal of the collector of Q2 is high (5 V), so, Q1 will switch on. When Q1 switch off, the input voltage of VCO is:

Equation 4

푅2 푉1 = ( )푉퐶퐶 푅2 − 푅3

The VCO output signal frequency is f1. When Q1 switch on, the input voltage of VCO is (Assume the resistance of Q1 is only a few ohm)

Equation 5

푅1//푅2 푉2 = ( )푉퐶퐶 (푅1//푅2) + 푅3

At this moment, the output signal frequency of VCO is f2. So, we just need to adjust R1 and R2, then the output signal frequencies of VCO will become f1 and f2 which are 1370 Hz and 870 Hz, respectively. In figure (3.14), the two amplifier, R1, R4, R5, R6, R8, R10, C1, C3, C5 and C6 comprise a 4th order low-pass filter. The objective is to remove the unwanted signal from the LM566 VCO output (TP2), so that we can obtain the sinusoidal waveform signal.[11]

Figure (3.14) shows the simulation of the modulation circuit using LM566 FSK generator. Figure (3.15) shows the actual circuit implementation.

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CHAPTER THREE METHODOLOGY AND DESIGN

The mapping of the resistors from the equations to the simulation:

 R1 from equations: R12 in the simulation.

 R2 from equations: R11 in the simulation.

 R3 from equations: R1 in the simulation.

Figure 3.14: LM566 circuit simulation.

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CHAPTER THREE METHODOLOGY AND DESIGN

Figure 3.15: LM566 circuit implementation

3.4.2 Step two: Demodulation 3.4.2.1 Using Phase Locked Loop Generally, phase locked loop (PLL) can be divided into 3 main parts, which are the phase detector (PD), loop filter (LF) and voltage controlled oscillator (VCO). The block diagram of PLL is shown in figure 3.16.

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CHAPTER THREE METHODOLOGY AND DESIGN

Phase Loop filter Amp. Detector

Figure 3.16: Block diagram of PLL.

VCO

Figure 3.17: Phase Locked Loop components

In figure 3.17, when the input signal frequency changes, the output signal of the phase detector will change and so as well as the output voltage.

when the input signal frequency changes, the output signal of the phase detector will change and so as well as the output voltage. We can use this characteristic to design the FSK demodulator. Let the FSK signal frequencies as f1 and f2, then these signals are inputted to the input terminal of figure 3.16. When the input signal frequency is f1, the output voltage will be V1. When the input signal frequency is f2, the output voltage is V2. At this moment, we have converted the frequency to voltage. If we add a comparator at the output terminal of PLL, the reference

Figure 3.18: 4046 PLL simulation

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CHAPTER THREE METHODOLOGY AND DESIGN voltage will lie between V1 and V2, then at the output terminal of comparator, we are able to obtain the digital signal, which is the demodulated FSK signal.[12]

Pin 1 is connected to negative voltage supply, -5 V. Pins 2 and 3 are connected to the input signals, but normally pin 3 will connect to ground. If pins 4 and 5 are connected to frequency multiplier, then various multiplications of frequencies can be obtained. In this experiment, we need not use the frequency multiplier; therefore, these two pins are shorted. Pin 6 is the reference voltage output. The internal resistor (Rx) of pin 7 and the external capacitor (C3) comprise a loop filter. Pin 8 is connected to timing resistor (VR1). Pin 9 is connected to timing capacitor (C2). Pin 10 the positive voltage supply +5 V of LM565.

In the design of the PLL three concepts must be taken into consideration:

1) The Free-Running Frequency of LM565:

When LM565 without any input signal, the output signal of VCO is called free-running frequency. The C2 is timing capacitor and the variable resistor VR1 is timing resistor. The

free-running frequency (fo) of VCO of the LM565 is determined by C2 and VR1. The expression is:

Equation 6 1.2 푓표 = 4푉푅1퐶2

2) The locked Range of LM565:

When the PLL is in locked condition, if the frequency of the input signal (fi) deviates from fo, then the PLL will remain in the locked condition. When fi reaches a certain frequency, which the PLL is not able to lock, then the difference between fi and fo is called the locked range. The locked range of LM565 can be expressed as:

Equation 7

8푓표 8푓표 푓퐿 = = 푉퐶 푉퐶퐶 − 푉퐸퐸

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CHAPTER THREE METHODOLOGY AND DESIGN

3) The Capture Range of LM565

The initial mode of PLL is in unlocked condition, then the frequency of the input signal (fi) will come near to fo. When fi reaches a certain frequency, the PLL will be in locked condition. At this moment, the difference between fi and fo is called the capture range. The captured range of LM565 can be expressed as:

Equation 8

1 2휋 × 푓퐿 푓퐶 = √ 8 2 3.6 × 10 × 퐶2

[12]

3.4.3 Step three: coupling circuit The coupler is the heart of the PLC system. The connection between the power line and the modulation and demodulation circuits is done using line trap and line coupler.

In our coupling circuit a double LC bandpass filter is used to provide efficient rejection 50Hz signal (high pass) and anti-aliasing (low pass) for digital filter without any adjustment or tunable from the components. A unidirectional transient suppressor (SA5.0A, D1) is connected to protect from overvoltage. It also protects the transmitter from negative transient voltage which also might damage the circuit output amplifier

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CHAPTER THREE METHODOLOGY AND DESIGN

Figure 3.19: coupling circuit simulation.

Principle of superposition can be used in coupling circuit analysis. Assuming the 240Vrms, 50Hz AC sine wave as a signal source a. Thevenin Equivalent Output circuit can be calculated as follows:

Equation 9

푍2 푉퐶푂 = 푉퐼푁( ) 푍1 − 푍2

Where: 푍1 = 푋퐶1 + 푋퐿1 and 푍2 = 푋퐶3||푋퐿2

휔 = 2휋푓 = 2 × 3.1416 × 50 = 314.16

1 1 푋 = = = 67725.51 퐶1 휔×퐶1 314.159×47×10−9

푋퐶1 = 푋퐶3 = 67725.51

−6 푋퐿1 = 휔 × 퐿1 = 2 × 3.1416 × 50 × 47 × 10 = 0.014756

푍1 = −푗67725.51 + 푗0.014765 = −푗67725.49

−푗67725.51×푗0.014765 (67725.51∠−90)(0.014765∠90) 푍 = = 2 −푗67725.51+푗0.014765 −푗67725.495

9999.967∠0 999.967∠0 = = −푗67725.495 67725.495∠−90

= 0.014765∠90 = 푗0.014765

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CHAPTER THREE METHODOLOGY AND DESIGN

0.014765∠90 푉 = 240∠90 ( ) 푂퐶 −푗67725.49+푗0.14765

0.014765∠90 = 240∠90 ( ) 67725.49∠−90

= 240∠90 (2.18 × 10−7∠180)

= 52 × 10−6∠270

This ratio will effectively eliminate the 230VRMS signal to 52 uV with attenuation of 133.28dB.

Connection of the coupling circuit to the transmitter circuit and receiver circuit is shown in figure (3-19), figure (3-20) respectively.

Figure 3.20: modulation circuit connected to coupling circuit.

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CHAPTER THREE METHODOLOGY AND DESIGN

Figure 3.21: demodulation circuit connected to coupling circuit.

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CHAPTER FOUR RESULTS AND DISCUSSION

4 CHAPTER FOUR: RESULT AND DISCUSSION 4.1 Overview This chapter is continuity to the methodology and design chapter, which describes the implementation steps, testing, measuring and results.

Some calculations are made to obtain the required values of the components in the modulation, demodulation, filters and coupling circuits.

Results are displayed in form of tables and figures. 4.2 Calculations 4.2.1 FSK modulation 4.2.1.1 Using timer circuit Using equations (1) and (2) to obtain the required frequencies:

Mark frequency=870

1.45 푓 = 푅푎 + 2푅푏

푅푎 = 52푘

푅푏 = 58푘

Space frequency=1370

1.45 푓 = ((푅푎||푅푐) + 2푅푏)퐶

푅푐 = 50푘

퐶 = 10푛푓

Figures (4.1) and figure (4.2) show the last 555 circuit components values and the simulation result.

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CHAPTER FOUR RESULTS AND DISCUSSION

Figure 4.3: timer circuit with prober values

Figure 4.2: timer circuit output Figure 4.1: timer circuit output

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CHAPTER FOUR RESULTS AND DISCUSSION

Figure 4.4: real circuit result

4.2.1.2 Using VCO circuit The components values were measured to obtain frequency of 870 Hz and 1370 Hz. Using formulas (3), (4) and (5) in chapter 3.

2 푉퐶퐶 − 푉퐼푁 푓0 = ( ) 푅10퐶5 푉퐶퐶

To obtain the value of VR2:

After substitute:

fo = 1370, VCC = 12, R10 = 5.6 k, C5 = 0.1 u

We find that VIN = 7.3968 = V1.

After using equation:

푉푅2 푉1 = ( )푉퐶퐶 푉푅2 − 푅6

VR2 = 3.105 kΩ

To obtain the value of VR1:

fo = 870, VCC = 12, R10 = 5.6 k, C5 = 0.1 u, VR2 = 3.105,

we find that VIN = 9.0768 = V2

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CHAPTER FOUR RESULTS AND DISCUSSION

after using equation:

푉푅1//푉푅2 푉2 = ( )푉퐶퐶 (푉푅1//푉푅2) + 푅6

VR1 = 3.33 kΩ

Figure (4.6) shows the final modulation circuit simulation with the calculated values. Figure (4.5) shows the output from the modulation circuit with LM566 chip.

Figure 4.6: VCO final circuit simulation

Figure 4.5: FSK modulation output

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CHAPTER FOUR RESULTS AND DISCUSSION

4.2.2 Demodulation using PLL: For 4046 chip there are different equations to find the values of capture range and locked range[13].

Equation 10 1 푓푚푖푛 = 푅2 × (퐶15 + 32푝퐹)

Equation 11 1 푓푚푎푥 = 푓푚푖푛 + 푅1 × (퐶15 + 32푝퐹)

Where R2 the resistor connected to pin 12 in the 4046 chip, R1 the resistor connected to the 11th pin in the 4046 chip.

th To obtain the capture range of 0Hz to 5kHz the value of R2 must equal infinity, so the 12 pin is an open circuit. R1 supposed to be 300kΩ, then C15 after calculations will equal 360 pF.

Figure 4.7: transceiver circuit

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CHAPTER FOUR RESULTS AND DISCUSSION

Figure (4.6) shows the overall circuit simulation: transmitter and receiver circuits. Figure (4.7) shows the transmitted data and result of the modulated signal and the signal after the demodulation.

Figure 4.8: overall transceiver circuit results

4.2.3 Coupling circuit Figure 4.8 is the simulation result for the coupling circuit

Parameter values was calculated to give the wanted results.

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CHAPTER FOUR RESULTS AND DISCUSSION

Table 4-1: coupling circuit parameters

Parameter Value

L1 47u

L2 47u

C1 10n

C2 1u

C3 47u

C4 47n

Figure 4.9: coupling circuit result

4.3 Discussion 4.3.1 Transmitter In the first design step which was generating FSK signal three designs were tested.

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CHAPTER FOUR RESULTS AND DISCUSSION

Multiplexer design Was The simplest one but it's simulation results was not always satisfying as shown in figure (4.9). FSK signal was not always obtained, only in certain values of data frequency. To obtain good results space and mark frequencies must not be separated by a large range of frequency from the frequency of the transmitted data.

Thus this choice was eliminated.

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CHAPTER FOUR RESULTS AND DISCUSSION

Figure 4.10: Mux bad result

Figure 4.11: Mux good result

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CHAPTER FOUR RESULTS AND DISCUSSION

Another two designs were tested and gave good results at required modulation frequencies for any data frequency as shown in figures (4.1) (4.4)

As seen in the result of the 555 timer real circuit the output signal was not accurate because components values were not accurate.

A design using monolithic function generator XR2206 would be a good solution with simple circuit but the chip has no simulation model in proteus and not available in market here in Sudan.

The VCO design was our last Chosen design because there is no need for function generator (smaller circuit).

In the LM566 circuit the output frequencies are less than the calculated frequencies by approximately 200 Hz. For high frequencies it make no differences.

From the frequency equation in chapter 3, the output frequency is affected by the values of

VR1 and VR2 for each values of R10 and C5. In high frequencies the values of R10 and C5 must be calculated to obtain the required frequency values.

4.3.2 Receiver Capture range was chosen to be from zero to 5kHz to ensure that our transmitted data will pass through the 4046 demodulator. As we know that the coupling circuit will block the 50 or 60 Hz power signal.

The components that are connected to 4046 chip must be calculated carefully within the specified range to ensure that the demodulation would be perfectly done.

A delay between the digital transmitted data and the demodulated signal because of the filters and components that the signal pass through. In real implementation of the circuit the delay will increase according to the effect of power lines and the trap circuits.

4.3.3 Coupling The designed circuit blocks the 240v 50hz signal from modem circuit as shown in figure (4.8) and permit the modulated signal to be injected into the power line. usually coupling circuit

59

CHAPTER FOUR RESULTS AND DISCUSSION is more complicated here we used the simplest circuit that can protect our circuit and make the propagation of the signal through power line possible.

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CHAPTER FIVE CONCLUSION AND RECOMMENDATIONS

5 CHAPTER FIVE: CONCLUSION AND RECOMINDATIONS

5.1 Conclusion The power lines are not designed to be used as communication medium it’s too noisy so recovering data will be difficult, also it is not safe can damage our electronic circuit.

Modulation techniques was investigated to select proper one that make it easier for the data to be recovered taking into consideration complexity and cost.

FSK was the modulation technique used at last because it’s simple, easy to implement and the fact that there are two frequencies one representing 0 logic and the other 1 logic make it easier to recover the digital data even if one of the frequencies have been attenuated. Modulator and demodulator circuits was designed using VCO 566 and PLL 4046 chips respectively.

Concept of inserting the data into the power line and keeping our circuit from danger was investigated. Design for the coupling circuit was implemented and tested in simulation. design consist of low pass filter to block electricity signal 50hz and isolation transformer. 5.2 Problems and solutions  Components are not always available for students (Xr2206 was first selected chip for modulation not available in Sudan thus new design was implemented))  No simulation model for PLL 565 chip. It was replaced by new design with 4046 chip.  Plc does not have universal standards and regulations, what made study of the technology harder.  We were not able to Simulate the full system (modem with the coupling circuit) using proutues ) each one was simulated separately. . 5.3 Future works Full PLC system design would be implemented so it could be used in reality to transmit data in many applications such as home automation, automatic meter reading and broadband over power lines.

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REFERENCES

[1] T. M. Haq, “Application of Power Line Carrier (PLC) in Automated Meter Reading (AMR) and Evaluating Non-Technical Loss (NTL),” Int. J. Eng. Res. Technol., vol. 2, no. 8, pp. 766–774, 2013.

[2] K. Achievements, “Energy Integration in South Asia Region Progress , Key Achievements and Way forward,” 2017.

[3] A. A. Aderemi, A. A. Adeyemi, and A. I. Yury, “Power Line Communication Technologies: Modeling and Simulation of PRIME Physical Layer,” World Congr. Eng. Comput. Sci., vol. II, 2012.

[4] T. F. Bissyandé and G. van Stam, “e-Infrastructure and e-Services for Developing Countries: 5th International Conference, AFRICOMM 2013, Blantyre, Malawi, November 25-27, 2013, Revised Selected Papers,” Lect. Notes Inst. Comput. Sci. Soc. Telecommun. Eng. LNICST, vol. 135 LNICST, pp. 12–21, 2014.

[5] R. D. Caytiles and S. Lee, “A survey of recent power line communication technologies for smart micro grid,” Int. J. Softw. Eng. its Appl., vol. 9, no. 12, pp. 251–258, 2015.

[6] F. Report, “EECE 501 Final Year Project,” pp. 1–97.

[7] K. H. Zuberi, “Powerline Carrier (PLC) Communication Systems,” Stock. IMIT, no. September, pp. 4565–4570, 2003.

[8] M. Control, “Research and Implementation of the Low Voltage Power Line Communication System Based on OFDM Rong Hua , Fuxiang Yi,” no. Amcce, pp. 445–450, 2015.

[9] T. M. Haq, “Study of Application of Power Line Carrier ( PLC ) in Automated Meter Reading ( AMR ) and Evaluating Non-Technical Loss,” 2015.

[10] K. Dostert, “Powerline Communications,” Dep. Inf. Technol. Lund Univ., pp. 1– 103, 2001.

[11] G. Faculty, M. K. A. Foul, and E. Objectives, “FSK Modulator,” pp. 1–10.

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[12] G. Faculty, M. K. A. Foul, and E. Objectives, “FSK Demodulator,” pp. 1–10.

[13] D. Maksimovic, “1 Phase-Locked Loop Concepts,” Lect. Notes, pp. 1–10, 1997.

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