UNIVERSITY OF NAIROBI USE OF GIS TO DEPICT POWER INTERRUPTIONS CASE STUDY: NAIROBI COUNTY AKOTH RUZUNA F19/3911/2009 A project report submitted to the Department of Geospatial and Space Technology in partial fulfillment of the requirements for the award of the degree of: Bachelor of Science in Geospatial Engineering APRIL 2014 0 Abstract This project tries to improve and add to the communication problem between the Kenya Power and Lighting Company and its consumers by providing an alternative method of relaying power disruption information. This is an alternative method to the traditional newspaper notices which do not clearly make consumers understand why only some parts of the same locality fail to have power. The project result is a web mapping application which displays the areas experiencing power outages at a particular time. The system can be installed by the Kenya Power and Lighting Company for easy updating of the power coverage and for checking the efficiency of the power network in the area of study. The web mapping application can be managed by personnel, equipped with the identity of the network that log on to it and update as required. It also allows the persons viewing the page to share it with others in other social networks. The system also allows for digital archiving previous power disruptions from which areas frequently affected can be determined. The web application is developed using Java script and Extensible Markup Language (XML), the server based program is written in HTML and the databases are My Structured Query Language (MySQL). The computer application is developed using Java and also contains a MySQL database. The Web page is designed using HTML and is connected to Google Maps using Google Maps Application Programming Interface (API). 1 Acknowledgements I would like to acknowledge and thank my supervisor Mr. D.N. Siriba for his support and guidance throughout the duration of the project study. I would also like to thank the Chief Manager of Operations and Management department at the Kenya Power and Lighting Company for his hospitality, generosity and readiness to assist whenever needed. My special thanks to Mr. M. Omondi of the same department who not only availed the data but also helped translate it. I would like to thank my family, my siblings Edgar and Eader, and most importantly my mother, Ms. Amina Baraka for the sacrifices she has made to educate me. I would like to thank my friend and classmate Justus Muhando for helping me design the web page. Finally I would like to thank my friends and classmates Justus Muhando and Rose Njambi for their moral support and help as I did my project. 2 DEDICATION I dedicate this report to my mother, Ms. Amina Baraka, Brother, Edgar and sister, Eader. 3 TABLE OF CONTENTS ABSTRACT………………………………………………………………………..……..i ACKNOWLEDGEMENTS……………………………………………………………...ii DEDICATION……………………………………………………………………………iii TABLE OF CONTENTS..........................................................................................iv LIST OF ABBREVIATIONS AND SYNONYMS……………………………………...v CHAPTER 1: INTRODUCTION………………………………………………………..1 1.1 1.2 1.3 1.4 Background…………………………………………………………….……3 Problem statement…………………………………………………………..4 Objectives………………………………………………………………….....5 Organization of the report……………………………………………….…..5 CHAPTER 2: LITERATURE REVIEW………………………………………….……..6 2.1 Causes of power interruptions…………………………………………….….6 2.2 Definitions………………………………………………………………….…...6 2.2.1 Electricity generation ………………………………………….……...6 2.2.2 Electricity distribution network ……………………………….………6 2.2.3 Electricity power transmission ……………………………….………7 2.2.4 Electricity distribution……………………………………………….…7 2.3 Historical development in transmission and distribution of electricity….....8 2.4 Electricity generation and transmission……………………………….….….8 2.4.1 Electric power grid……………………………………………….…….9 2.4.2 Substations……………………………………………………….……9 2.4.3 Power Grid in Nairobi…………………………………………………9 2.5 Power Interruptions…………………………………………………………...12 CHAPTER 3: METHODOLOGY……………………………………………………...14 3.1 The study area……………………………………………………………….…14 4 3.2 Data sources and tools ……………………………………………………..14 3.2.1 Data sources…………………………………………………………14 3.2.2 Tools…………………………………………………………………..14 3.3 Overview of methodology…………………………………………………..15 3.4 User needs assessment……………………………………………………15 3.5 Data preparation…………………………………………………………….16 3.5.1 Description of the data……………………………………………...17 3.5.2 Manipulation of the data……………………………………………18 3.6 Data capture and editing…………………………………………………...19 3.6.1 Editing………………………………………………………………..19 3.6.2 Creation of Geodatabase…………………………………………...21 3.6.3 Creation of the web page…………………………………………..25 CHAPTER 4: RESULTS AND ANALYSIS……………………………………….27 4.1 Results………………………………………………………………………27 4.2 Analysis of results………………………………………………………….30 CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS………………….35 5.1 Conclusions …………………………………………………………………35 5.2 Recommendations………………………………………………………….35 REFERENCES……………………………………………………………………….37 5 LIST FIGURES Figure 1: Diagram showing flow of power from the main station…………………….7 Figure 2: Diagram of transmission network…………………………………………….11 Figure 3: Map of Distribution network…………………………………………………..12 Figure 4: flow chart showing organization of project…………………………………..15 Figure 5: Map of the Grid Network………………………………………………………16 Figure 6: Flow chart showing voltage step down…………………………………………17 Figure 7: Reduced network………………………………………………………………18 Figure 8: A screen shot of geodatabase formation……………………………………22 Figure 9: Relationship creation………………………………………………………….23 Figure 10: Relationships created………………………………………………………..23 Figure 11: Query statements……………………………………………………………..24 Figure 12: Homepage…………………………………………………………………….25 Figure 13: HTML code…………………………………………………………………….25 Figure 14: JavaScript……………………………………………………………………..26 Figure 15: Icons……………………………………………………………………………27 Figure 16: Screen shot of station selection…………………………………………….28 Figure 17: Check box……………………………………………………………………..29 Figure 18: Querying……………………………………………………………………….29 Figure 19: map of power interruptions………………………………………………….32 Figure 20: Screenshot of power disruptions map……………………………………..33 Figure 21: Page sharing………………………………………………………………….34 6 LIST OF TABLES Table 1: Attribute table for the feeders………………………………………………….20 Table 2: Attribute table for the primary substations……………………………………20 Table 3: A section of the attribute table for distribution lines…………………………21 Table 4: Field (state)………………………………………………………………………24 Table5: Access table status of power off……………………………………………….30 Table 6: ArcGIS status of power off……………………………………………………..31 7 LIST OF ABBREVIATIONS AND ACRONYMS GIS- Geography Information Systems HTML- Hyper text Markup Language KPLC- Kenya Power and Lighting Company KV- Kilo Volts LV- Low Voltage MySQL- My Structured Query Language SQL- Structured Query Language 8 CHAPTER 1: INTRODUCTION BACKGROUND Every year the Kenya Power and Lighting Company invests a lot of time, money and other resources maintaining and improving electricity network and its customer service modalities. It is not possible, however to have a completely efficient network, thus power outages are bound to happen. Given the harsh reality that there can be no way around power interruptions, we are faced with the challenge of developing mechanisms that can aid in smooth operations of our daily activities even when experiencing these outages. We live in an information society where people tend to embrace the best means possible of obtaining information that they need in their daily living with ease. People want to accomplish tasks from the comfort of their couches. Business people can communicate much easily by coming up with systems that reach their consumers wherever they are. In Kenya today, a lot of projects are under way in a bid to achieve the vision 2030. It is essential therefore that communication about any situation that can stall any project be communicated earlier enough such as information on planned power interruptions. This enables efficient planning in all areas of development. It is relevant to devise a means of getting such information to the people as it comes up. Power interruptions are spatial in nature since they occur in specified geographical locations at a particular time. It is thus possible to integrate tools of GIS and the knowledge from the discipline to depict information on power disruptions for use by the relevant stake holders. Electricity supply in Kenya has solely been the responsibility of the Kenya Power and Lighting Company. The company organizes and carries out matters affecting power supply on its own terms. There are instances where power interruption notices are given out with an allowance of only one day. Some consumers may not be comfortable with this idea but are not left with much choice. This not only makes it difficult for the consumers but also affects the company itself in terms of efficiency. Power provision can be explored using GIS to ease interaction between supplier (KPLC) and consumers. KPLC is allowed by the laws of Kenya under rule 27 of the electric rules(Constitution of Kenya Cap 314) to disrupt power supply to various regions of the 9 country from time to time to enable them carry out certain important duties which could be as simple as maintenance. Given that KPLC serves the whole country, it is tasked with the responsibility of ensuring that it can service every region as effectively and efficiently as possible irrespective of geographical or any other challenges that it encounters. Currently, the only means of communication to the consumers about power interruptions is through the print media. This is done by putting out public notices on newspapers with the obvious assumption that everyone eventually gets to be able to not only access the information but also do so in good time. GIS can be used to show areas that are scheduled to experience power outage. This will enable a lot of consumers to access the information as soon as it is made available. Web GIS can be applied to achieve this. Electricity supply covers the whole country through a distribution network. There are major stations with the highest voltages located at different points in the country. From these there are subsequent step down stations that eventually service households. The power lines to all areas form the distribution network and each power line is formally referred to as a feeder. Feeders are of different voltages depending on how large the region is that it serves. Most feeders are 66kv. These feeders are named or rather coded to provide the linkage between them and the areas they cover. Up until know the KPLC has been able to use GIS to digitize the network GIS can be used to relate the power network to all areas that receive electric power supply from KPLC. The relationship between the various power lines and power stations can be shown as illustrated in Figure 1 above. Power is generated in small voltages but is stepped up at the main station to very high voltages. These voltages are subsequently carried by power lines t smaller substations. Other power lines pick up transmission to much smaller stations until they get to the consumers. Figure 1 shows this flow of power. In this case, Nairobi region is used as a case study. GIS is used to analyze the power grid in the area and to establish how to link the various parts of the network to the areas that they supply power to. This can go a long way in enhancing maintenance protocols and customer services at the company as well as keeping consumers informed. 10 STATEMENT OF THE PROBLEM In Kenya, news about scheduled power interruptions is communicated to the consumers in advance through notices in the newspapers. KPLC uploads these notices on to their website so that people can access them. The obvious assumption is that everyone eventually accesses the information in time. However, it is arguable that not every consumer buys newspapers daily and therefore will definitely get the information. Moreover, even for those who do, the information may not be timely. Some areas tend to bear the brunt of these power outages more than others. The Kenya Power and Lighting Company aims at efficient and timely communication with consumers on their activities especially when it comes to power interruptions. Most consumers are often caught off their guard when power is disabled in their areas because they did not access the notices or by the time the notices came out they had already made plans that are then bound to be affected. It is also possible that most consumers don’t check for these notices even when they do have access to these notices. On the other hand, it is indeed a fact that power interruptions cannot be avoided. It’s like the weather, we cannot control it but we want to be ready anyway. The question therefore is whether enough has been done to overcome the challenges brought about by the frequent power interruptions and if whatever we have is adequate in dealing with the challenges. Newspaper notices have worked over the years and still are but we can device other modes of relaying this information to compliment them and ease communication between supplier and consumers. This project seeks to use GIS to show the relationship between the power grid network and the regions they supply power to while at the same time indicating power outages in an area in advance. Given the society today is in the information age most people obtain information they need mostly from the Internet. Today, it is possible to locate one position online at any point in time from the maps available. Social networks such as Facebook, Twitter, and My space among others ensure that there is always a large magnitude of audience in the Internet. This audience cuts across any divide. Using its website, Facebook and Twitter accounts and other accounts in its domain, KPLC can share the web page on power interruptions with its consumers in the shortest time possible and reach a much larger number of people at the same time. In Kenya it is estimated that at least 93% of 11 the population are mobile phone subscribers (e-library 2012). Between the years 2011 and 2012 alone there was a 95% increase in Internet users in the country and the number has increased drastically according to the Communications Commission of Kenya. Kenya also has a 36.6% Internet penetration (Humanipo) which is higher than the world’s average of 26.6%. This implies that use of Internet to communicate information on power outages is bound to be more effective especially in Kenya. In one twitter account alone, KPLC has close to 10000 followers and even more Facebook friends. This would enable them to share information on power disruptions as soon as they make the changes with more consumers in the shortest time possible. Against this backdrop it is possible to come up with a web based page that depicts scheduled power interruptions at any point in time using GIS. When the print media avails the notices on power interruptions, it merely gives the names of the places affected. This is done by listing. This does not give an idea of the extent of the outage on a particular day. If this could however be depicted on a map then it would be much easier to see the extent of the areas affected by power outages and possibly raise questions why a very large area is without electricity in one day. There is also the fact that the electricity network organization is arguably complicated in its structuring. Electricity network in an area is called its power grid. The power grid of a region consists of the transmission and distribution networks. Inside KPLC as a company, the departments responsible for distribution and transmission are separate. The distribution and transmission networks are not linked. The department that gives out the names of areas that are scheduled to experience power interruptions is also separate. Using GIS to create a linkage between these networks overlay it accurately on the map of Nairobi and develop a web page for the same will enable the personnel in charge to be able to tell just from the display on their screens whether the disruptions are on the transmission end or the distribution end. This will also enable to check the efficient flow of the electricity network and help device alternative routes for power lines. In mapping all areas that are beneficiaries of the Kenya power and lighting company, deducing geographically areas covered by the same power lines and incorporating the time aspect, it is possible to have these scheduled power interruptions known to the 12 consumers early enough. This way, things like planning for events can be done appropriately. OBJECTIVES Main Objective 1. To come up with a web based map of Nairobi that shows areas experiencing power interruptions at a particular time. Other objectives 1. Link between the transmission and distribution networks 2. To provide an alternative means of informing people about scheduled power disruptions. ORGANIZATION OF THE REPORT This project is organized in five chapters. Chapter 1 contains the background information related to power interruptions and electricity distribution, the problem statement, the objectives of the study, and the organization of the report. Chapter two contains the literature review which outlines the definitions, history, scope and relevance of the study. It gives the advancements in electricity so far. In the third chapter there is the methodology which gives a step by step account of tasks undertaken to achieve the results. This entails data collection, creation of the database, creation of relationships, showing on a map, model building and finally linking online. Chapter four presents the results and the analysis of the results and chapter five gives conclusions and recommendations in view of the obtained results. CHAPTER 2: LITERATURE REVIEW 13 2.1 Causes of Power interruptions There are various reasons why power interruptions may occur. These could be planned or unplanned. In the case of planned power interruptions, they are usually necessary to allow for important maintenance tasks to be undertaken on the network. Unplanned power interruptions occur for diverse reasons, most of which are inevitable situations for example, high winds, storms and lightning strikes, debris or vegetation hitting power lines, animal life such as birds or possums, vandalism, pole top fires, overloads, equipment failure, wiring or appliance faults on property, a fire or an accident(vehicle or machinery) among others. This project focuses on planned power interruptions. Power may be interrupted so as to undertake any of the following: i. Undertake upgrades or planned maintenance to the electricity network ii. Upgrade supply to existing or connect new customers iii. Replace one’s metering equipment or service line. iv. Safely complete vegetation maintenance. 2.2 Definition Electricity generation is the process of generating electric power from other sources of primary energy. The basic method of electricity generation is by the movement of a loop of wire between magnetic poles (Michael Faraday, 1820s to 1830s). This is the first process of electricity delivery to consumers. The electric power industry is responsible for electricity transmission, distribution, storage and recovery of power. Electricity is often generated at a power station by electromechanical generators driven by heat engines. Power transformers are used to transmit electricity from the Central power stations at high voltages with low loss. Electricity distribution network is a regional grid that branches from a national grid to deliver power to industrial commercial and domestic users. Electricity generation is often done with electronic generators but can also be supplied by chemical sources such as batteries or by other means from a wide variety of energy sources. Electric power is generally supplied to businesses and homes by the electric power industry. Electricity is usually sold by the Kilowatt hour which is the product of power in kilowatts 14 multiplied by the running time in hours. Electric utilities measure power using electricity meters which keep a running total of the electric energy delivered to a customer. Electricity power transmission is the bulk transfer of electrical energy from generating power plants to electrical power substations located near demand centers. The interconnection between transmission lines forms what is referred to as the transmission network. Electricity distribution on the other hand is the local wiring between the high voltage substations and the customers. It is the final stage of delivery of electricity to the end users. The distribution network system carries electricity from the transmission system and delivers it to the consumers. The combination of the electricity transmission and distribution networks is called the power grid (National grid). Electricity distribution network often include medium voltage power lines, substations and pole mounted transformers. power station transmiss ion substation transmiss ion substation primary substation secondar y substation CUSTOM ER CUSTOM ER primary substation secondar y substation CUSTOM ER CUSTOM ER secondar y substation CUSTOM ER CUSTOM ER primary substation secondar y substation CUSTOM ER CUSTOM ER secondar y substation CUSTOM ER CUSTOM ER primary substation secondar y substation CUSTOM ER CUSTOM ER secondar y substation CUSTOM ER CUSTOM ER secondar y substation CUSTOM ER CUSTOM ER Figure 1: Flow of power 15 2.3 HISTORICAL DEVELOPMENT IN TRANSMISSION AND DISTRIBUTION OF ELECTRICITY Initially, direct current (DC), were largely employed in the distribution process. At this point in time, there was no way of changing DC voltages thus the loads, generation and transmission was mostly done at the same voltages. This meant that low voltages were used and this in turn required less insulation for safe distribution especially within buildings. However, this resulted to great losses along the cables and to minimize these losses thick cables and local generators were used. The generating plants had to be at least within 2.4 km of the furthest customer to avoid expensive conductors. Eventually, alternating current (AC) was introduced and it soon became the major mode of transmission of power. In this scenario, power transformers that were installed at power stations were used to raise the voltage from the generators, and the transformers at local substations could be used to reduce voltage to supply loads. Increasing the voltage, reduced the current in the transmission and distribution lines and hence the size of the conductors and distribution losses (Hughes et al, 1993). Consequently, it became economical to distribute power over long distances. 2.4 ELECTRICITY GENERATION AND TRANSMISSION Electric power is normally generated at 11-25kv at a power station. It is the stepped up to 400kv, 220kv or 132kv for transmission over long distances. This transmission network is the connected to load centers (cities) through a sub transmission network of lines at voltages of 33kv to 230kv. The lines end at substations where they are subsequently stepped down to 25kv or less for distribution to customers. Most transmission lines use high voltage to reduce power loss over long distances. Power is either transmitted through overhead power lines or by underground transmission. The latter has high costs and more operational limitations but is sometimes preferred in urban and other sensitive areas. Overhead transmission voltage levels are considered to be 110kv and above. Lower voltages of 66kv or 33kv are often used at sub transmission levels. Voltages less than 33kv are used in distribution 16 (Oestergaard et al, 2001). Underground cables take up lesser right of way compared to overhead power lines and have less visibility and are rarely affected by bad weather. 2.4.1 Electric power grid A transmission grid is a network of power stations, transmission lines and substations. A power station is an industrial facility responsible for the generation of electric power. Substations are parts of an electrical grid that transform voltage from high to low or vice versa among other electrical functions. Several substations may exist between the consumers and the generating station. A substation may be owned and operated by an electrical utility or by a large industrial or commercial customer. A substation can include a transformer to change voltage levels between high transmission voltages and lower distribution voltages. 2.4.2 Substations These generally have protection, control, switching equipments and transformers. They may be on the surface, in fenced enclosures, underground or located in special purpose buildings. Substations may be described by their voltage class, applications within the power system, method used to insulate the connections or by the style or materials of the structures used. A transmission substation may have important distribution functions. A transmission substation connects two or more transmission lines. The most basic scenario is where all transmission lines have the same voltage in which case the substation consists of high voltage switches that allow lines to be connected or isolated for fault clearance and/or maintenance. Transmission substations can cover large areas of several acreages with multiple voltage levels. Examples of substations within Nairobi include, Juja, Ruaraka, Dandora and Embakasi substations. A distribution substation transfers power from the transmission system to the distribution system of an area. It decreases voltage to a level that is appropriate for local distribution. The input for a distribution substation is most likely to be two transmission lines or sub transmission lines. Input voltage is usually 220kv or 132kv as is the situation in Nairobi. The output is a number of feeders which are of 66kv in Nairobi 17 region. The feeders run along the streets mostly overhead (or sometimes underground especially within the central business district). They also power the distribution transformers near the customer premises. Distribution substations also isolate faults in either transmission or distribution systems. 2.4.3 Power Grid in Nairobi The national grid in Kenya is generally operated as an integral network linked by a 220kv and 132kv transmission network and there exists limited lengths of 66kv transmission lines in use which are mostly referred to as the feeders. Nairobi region as indicated in Figure 2 is covered by at least 16(set to rise) major transmission lines that originate from various power stations located within and outside Nairobi i.e Kamburu, Kiambere, Juja, Dandora, Kindaruma and Nairobi North substations. These transmission lines run at a voltage of either 220kv or 132kv and supply to the four major transmission substations: Juja, Dandora, Embakasi and Ruaraka. Sub transmission lines running at a voltage of 66kv each pick up transmission from the substations to primary substations which are relatively closer to the consumer locations and are more in number compared to the transmission substations. There are at least 35 primary substations spread all over the region and examples include Parklands, Ridgeways, Kitsuru, Karen, Westlands etc. Primary substations step down the voltages to distribution voltage (11kv). Distribution lines originate from these stations and supply power to various secondary transmission substations from which switches and service lines distribute to individual customers. 18 Figure 2: Diagram of Transmission network. 19 Figure 3 Map of distribution network 2.5 Power Interruptions Power interruption is a short term or long term loss of power supply to an area. It occurs for various reasons. These reasons can be planned or unplanned. Whichever the case, restoration of power should be swift and fast. Planned power interruptions are necessary to allow for essential maintenance to be done and sometimes to upgrade the network. Often, customers are informed in advance by way of newspapers, radio or text alerts. Unplanned power interruptions occur due to situations that are difficult to contain, for example, adverse weather conditions like storms, fires or car accidents. Accidental power failures usually occur because certain features of the network have been tampered with by the bad weather or accidents. These include faults at power stations, damage to electric transmission lines, substations, parts of the distribution system, a short circuit or overloading of the electric mains. Power outage can be said to be either brownout, transient or a blackout. A brownout is also referred to as sag. It is 20 the temporary drop in the voltage in an electrical supply. It causes lights to dim and results to poor equipment performance. A blackout is the total loss of power supply to an area and is severe. A transient is loss of power for just a few seconds or minutes due to a temporary fault on a power line. Under certain conditions, a network component may shut down and cause current fluctuations in neighboring segments of the network resulting to cascading power failure of a large section of the network and this could be a whole building or sometimes an entire city or even the whole electrical grid. This in most cases is unavoidable (Dobson et al, 2009). This project aims at showing how this does happen. There is also what is referred to as rolling blackout (planned power interruptions). It is intentionally engineered power shut down where delivery of electricity is stopped for non-overlapping periods of time over different parts of the distribution region. They are, in most instances safety precaution measures taken by the electrical company to avoid total power blackout in the system. Rolling blackouts can be restricted to just a small locality but can also cover an entire region. They are necessitated by insufficient generation capacity or inadequate transmission infrastructure to deliver power. 21 CHAPTER 3: METHODOLOGY 3.1 The Study Area The study area of this project is the Nairobi area which t lies within latitudes 1°10' S and 1°25' S and longitudes 36°40′E and 37°10E and occupies 696 square kilometers and is both the political and administrative headquarters of Kenya. It is entirely urban and bordered by Kiambu to the North, Thika to the West, Kajiado to the West and Machakos to the South. The study area is extended past the Nairobi County but within the proposed Nairobi Metropolitan area of Northern Kajiado. 3.2 Data sources and tools 3.2.1 Data sources The Grid A digitized network of the power grid in the study area was obtained from the Kenya Power and Lighting Company. Shapefiles containing information on transmission and distribution properties of the network were also obtained and these provided the basis for the creation of the database. 3.2.2 Tools a) .Hardware: A computer with 500GB memory, 2GB of RAM, 2.13GHz speed. A flash disk of capacity 2GB A printer. b).Software: ArcGIS 10.1 Microsoft Office Access 2007 22 The softwares above were chosen for their various capabilities. ArcGIS for its wide variety of mapping functions including its online connection and Microsoft office access because of provision to create tabular relationships and query statements. 3.3 Overview of Methodology This project was carried out in three phases. These are data collection, processing and presentation of the results. Data was obtained from the department of operations and management at the Kenya Power and Lighting Company. The data obtained was processed using GIS software and Microsoft office applications. The current chapter details the steps taken to achieve the objectives. This entails data identification, manipulation and capturing. Data collection Data processing Data preparation Creation of table relationships Web design Results Figure 4: Organization of project 3.4 User needs Assessment Every company strives towards efficiency in the delivery of its services. The KPLC is one such company. Currently, notices about scheduled power interruptions are relayed through newspapers. The departments that deal with Information on scheduled power interruptions and power distribution and transmission Network, work separately. A webpage showing areas experiencing power interruptions will not only ease the 23 diffusion of this information but will also enable the creation of a single database for both departments. The users will benefit from the system in that the grid is linked to the region that is served by the company, therefore, the personnel in charge just logs onto the system and disable power at a station, a line or a transformer and all the areas attached to the same will be affected accordingly. For the consumers, it will be possible for them to view this change as soon as it is made. 3.5 Data preparation The data that was obtained for this project were shapefiles that contained information on the various parts of the electric grid in the region. These shape files were saved in a folder and loaded onto ArcGIS 10.1. The Figure 5 below shows the form of the data as it was. Figure 5: A map of the grid network 24 3.5.1 Description of the data There are four major transmission stations. These are Juja, Ruaraka, Embakasi and Dandora. These stations are supplied by transmission lines that carry 220kv of electricity from the generating power stations. From the transmission substations, sub transmission lines called feeders take up transmission at stepped down voltages of 66kv and supplies this to primary substations distributed throughout the area. Distribution begins at these primary substations where power is further stepped down to 11kv and carried by distribution lines to secondary transmission stations commonly referred to as transformers. From the transformers power is distributed to consumers by service lines at much smaller voltages. The flow chart (Figure 6) below summarizes the transmission and distribution network. Transmission lines Transmission substation Feeders 66Kv Primary substation 66Kv 66Kv 11Kv Distribution lines Secondary transmission stations Service lines Figure 6: Flow chart showing voltage step down. 25 3.5.2 Manipulation of the data The network was reduced to a workable size for the project. This was done by following one line from the main source up to the distribution end. Consequently, a small part of the network was extracted and used for analysis as shown in Figure 7. Figure 7: Reduced network 26 3.6 Data capture and editing 3.6.1 Editing Attributes of the layers were edited so as to link the distribution network to the transmission network (The network was such that the shapefiles of the transmission and distribution were independent of each other). This was done considering the origin and destination of the transmission lines, feeders and distribution lines. Attention was also given to the unique identifiers of the stations and every line in the extracted network. It was also of essence to note all the lines that supply power to given station and how many that stem from that very station. This was done for all the stations in the network. Ideally transmission lines (220Kv) supply power to the transmission substations, but there are instances in the network that they supply from other transmission substations to others. This also applied to some feeders (66Kv) where instead of some of them taking up power from transmission substations they instead originated from primary substations and supplied power to other primary substations. In such instances the some records were transferred to one attribute table to another to conform to the intended flow. Transmission substations and primary substations had names which were unique to them. In the case of transmission lines fields added to provide them with unique identities. All feeders(66Kv) supplying power to one station say, Steel Billets (see Table 1, 2 and 3) which is a primary substation, were given the same identifier in relation to Steel Billets. A field was included in the attribute table for primary substations called, Name 10 in which the unique identifiers for all feeders (66Kv), supplying to Steel Billets was recorded. In the attribute table for feeders (66Kv) the field that was used to identify all those taking power to Steel Billets for instance was named Feeder 05. This identification was done for all stations. The edited shapefiles were then saved as a project on their own. 27 Table 1: Attribute table for the feeders. The field named Feeder o5 shows that the feeders were given a common name if they supply power to one station. Feeder 6, 7 and 8 are therefore all steel billets 66Kv meaning they take power to Steel Billets primary substation. Table 2: Attribute table for the primary substations. The field named `Name 10’ was used to connect the station Steel Billets with the feeders 6, 7 and 8 as they contained similar records. 28 Table 3: Attribute table for distribution lines (section). The highlighted field was used to connect the distribution lines from Steel Billets with the station Steel Billets. 3.6.2 Creation of Geodatabase A folder was created for the geodatabase named power. A personal geodatabase was then created in ArcGIS and all the shape files exported to it (see figure 8) 29 Figure 8: A screen shot of geodatabase formation. Microsoft office access was then used to create database relationships between the attribute tables of the shapefiles. This was done by establishing unique identifiers for each line and station and connecting them by origin and destinations. These unique identifiers are the primary keys which are used as foreign keys in the rest of the tables (see Figure 9 and 10). 30 Figure 9: Relationship creation. Primary Key Foreign Key Figure 10: Relationships created. A field called state was added to each table that would be used to determine and show that areas affected by that particular line or station was either on or off. The records in the field give the two possibilities which are either on or off. In ArcGIS a series of ones and zeroes were used. Ones to show that power is on and zero to show that power is off as illustrated in Table 4. 31 Table 4: Field(state). State The ticks in the boxes imply that those feeders are switched on. The next step was to write query statements for every table. An example is given in Figure 11. Figure 11: Query statements. A graphic user interface for directly accessing the database and changing the state was then created (see Figure 12) 32 Figure 12: Homepage. 3.6.3 Creation of the web page. A code was written in HTML and another in Javascript. The database created was then linked to it. The Web page’s domain name was made www.simoa.me.ke/power.html Figure 13: HTML code 33 Figure 14: Java Script 34 CHAPTER 4: RESULTS AND ANALYSIS 4.1 Results a). Performance of the Application This system is designed with a homepage. The homepage is equipped with icons for the various parts of the transmission and distribution network. These include, in descending order, the transmission lines, the transmission substations, the feeders, primary substations and the distribution lines. Each of these has its own icon (see Figure 15). Figure 15: Icons Icons When the user launches the application, the screen with the list of buttons described above appears. The user can access any of them by simply clicking on it. If a certain primary substation is supposed to be switched on for example, then the user will click on the primary substations button. When the user clicks on this button, another window appears on the screen (Figure 16). This window consists of three other buttons, a drop box and a state box. The user will use the drop box to scroll to the station of interest. 35 Figure 16: selecting a station. A user will click on it and the status box will immediately indicate whether that station is on or off at the time. In this case it is assumed that it was off so then the user activates the state by clicking the state button and a tick appears to show that it is now on (Figure 17). When this happens, the user ought to click the save record button to save the change made and then proceed to click the run query button which ultimately effects the changes throughout the system. This implies that every other power line or station that has its origin emanating from this one station is automatically switched on. 36 Figure 17: Check box Before the query is effected , a small window appears that checks if one is sure to proceed and if so then click yes and the process is complete (see Figure 18). Figure 18: Querying Run Query button 37 b). Analysis The queries basically change zeroes to ones and vice versa. When a station is off then the field called state contains zeroes only and the converse is true. In ArcGIS therefore, when power is off the field, state is queried to show only those areas with zeroes only and vice versa. In the figure below which is a table from access shows that all the primary stations are switched off since all the boxes in the status field are unchecked. Table 5: Power off The table above corresponds to the attribute table in Table 6 whose status field indicates zeroes for power being off. 38 Table 6: Power off in ArcGIS Figure 19, below shows how the map appears when the one primary station, say, Steel Billets, is the only station that is switched off. All secondary stations whose power origin is Steel Billets are affected and thus disappear from the map face. In the same manner, if a transmission station was to be switched off, the all primary stations, distribution lines and secondary stations that originate from it will disappear from the map face. In the web page however, the code was written such that those areas experiencing power outage are the ones that appear on the map face. 39 Figure 19: Map of power interruption Consequently this relationship was joined to the online database and thus these changes could be made online using html and Javascript. Figure 20 is a screen shot of the resultant web page. It indicates the layers for the various days affected and the map of Nairobi as the base layer as opposed to the current situation where the information is uploaded in form of pdf. Figure 21 a sharing button for Facebook has been included so that the administrator of this page can share it with all Facebook friends. 40 Figure 20: Power interruptions map 41 Figure 21: Map with a share button share button 42 CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS 5.1 Conclusions. The aim of this project was to come up with a system that enables KPLC notify consumers on scheduled power interruptions using GIS. The result would be a map face showing areas experiencing power interruptions. This was done by establishing connectors between different parts of the network in such a manner that these parts would be interdependent. The interdependency enabled the writing of query statements that would determine what appears on the map face-areas experiencing power outage. The transmission and distribution network are independent of each other. The aim of this project was to link the two networks to provide smooth and efficient flow of power in any part of the network. This was done by creating a geodatabase that links all the attributes of both networks I organized manner. This makes it easy to tell whether a problem is being experienced on the transmission end or the distribution end. Also, the geodatabase makes it easy to in co-operate other aspects of power distribution and transmission in one database. This project also aimed at giving the consumers and the KPLC a visual outlook of the extent of power disruptions on a particular day instead of the usual place names alone. With this given as a web page, sharing of this information is much easier and less costly. Depicting of power interruptions on a map was also possible. With the achievement of the objectives, it can be concluded that it is possible to communicate information on scheduled power interruptions to consumers more graphically by using mapping tools (GIS). In order to achieve this, the network must be clearly organized hence the development of the geodatabase. The designed web page will also enables storage of past power outage incidences and planned future outages. 5.2 Recommendations The following recommendations arise from the study: The system should be adopted to supplement the current notices in the newspapers so that even without access to newspapers one can still check online for information on scheduled power disruptions in the area of interest. 43 To reach out to as many consumers as possible KPLC can share the page through as many social networks as possible. From this project a real time application showing power availability in an area at a particular time can be developed. Using such database as created in this project, other aspects of power transmission and distribution other than power interruptions can be included such as public safety in relation to power, organize priority services etc. 44 REFERENCES Power Generation and Transmission, EnerNoc (2013-2014) at http://www.enernoc.com/our-resources Burke, J., Power Distribution Engineering, Marcel Dekker In., 1994. Kenya Power(2014), Power Interruptions(2014) at http://www.kplc.co.ke/index.php?id=44 Electric power transmission facts, pg 4, at http://www.aep.com/about transmission/docs/transmission facts.pdf National council on Electricity policy, Electricity Transmission: a primer.pdf Hughes Thomas P., Networks of power Electrification in Western Society 1880-1930, the John Hopkins University Press, Baltimore. HumanIPO (2011/2012) Kenya Records 95.63% Increase in Internet Use, (2011/2012) at http://www.humanipo.com/news Gabriel Demombynes, Aaron Thegeya, (2012) e-library, Kenya’s Mobile Revolution and the Promise of Mobile savings: Policy Research Working Papers, at interruptions (2014) at http://elibrary.worldbank.org/doi/book/101596/1813-9450-5988 Western Power, Common Causes of Power http://www.westernpower.com.au/customerservice/restoration Dobson et al (2007). Complex Systems analysis of Series of Blackouts: Cascading failure, Critical Points, and Self-organization. Chaos 17 2007. Wikipedia, Power outage at http://en.m.wikipedia.org/wiki/power_outage Kenya Law (2007), Energy Act Cap 314 Part 3-Electrical Energy (2007) at http://www.kenyalaw.org:8181/kenyaex/actview.xql?actud=CAP30314/part_||| Jacob Oestergaad et al, 2001 Energy Losses of Super Conducting Power Transmission Cables in the Grid 45 Margaret Wahito (July 2012) 3 in 4 Kenyans have a Mobile Phone at www.capitalfm.co.ke/business 46
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