The Preview of Development of Street Lighting in Tallinn

Transcription

1 8 th International Symposium Topical Problems in the Field of Electrical and Power Engineering Pärnu, Estonia, January 11-16, 29 The Preview of Development of Street Lighting in Tallinn Irena Milaševski, Raivo Teemets Tallinn University of Technology Abstract One of the earliest use of electricity was to illuminate streets. The basic purpose is to promote safety and convenience on the streets at night through adequate visibility, and to promote commercial enterprises. Statistics shows that good street-lighting installations bring about significant reductions in traffic accidents. It also acts as a strong deterrent to crime, and promotes more business in commercial areas. The purpose of this article is to discover how street-lighting system has changed and developed in the city of Tallinn. Keywords street-lighting, luminaire, street lighting network, control switchboard, electricity transmition lines,, monitoring and control on distance Introduction We have 365 days a year, and approximately 876 hours, we live in darkness 477 hours per year. Lighting has the ability to redefine the urban nightscape through dedicated visual features and effects. Hence it is a vital ingredient in humanizing the city and improving the quality of urban life. City beautification creates an environment that makes people feel safe and restores the pride and sense of identity as members of a community. Originally developed for purely functional reasons, urban lighting has evolved into a far-reaching, multifaceted entity. safety: on foot, on bicycles, in cars, buses and trams, good lighting is essential for safe movement at night; security: a well-lit urban environment is a big deterrent to criminals and vandals, making us feel more secure and more willing to go out and enjoy the night; orientation: light offers visual guidance, making the city layout easy to read promotion: be it subtle or brash, lighting is a highly effective from of advertising that attracts tourists and businesses; identity: custom-designed lighting schemes bring out the unique identity of a town or city and the districts within it; ambience: lighting alters peoples perception of urban surroundings by creating a fresh new atmosphere warm and cozy in quiet areas or bright and lively in the party districts spectacle: thanks to it flexibility and dynamism, light can turn the urban environment into a spectacular event that entertains, enlivens and captivates. Lighting directions of Tallinn city distributed on the basis of the three main objectives set by lighting task. The first goal of the lighting is functionality. Light, in particular, to ensure that aesthetic pleasure is the close links to the other lighting directions, which are is identity Tallinn strengthening and preservation of cultural heritage. Environmental friendliness, with a higher quality of light is the third purpose of lighting directions. Exploring the development of the development of street lighting should not forget not only about saving energy but also better quality and more attractive. 1 History of Street Lighting Before incandescent lamps, gas lighting was employed in cities. The earliest lamps required that a lamplighter tour the town at dusk, lighting each of the lamps, but later designs employed ignition devices that would automatically strike the flame when the gas supply was activated. The earliest of such street lamps were built in the Arab Empire, especially in Cordoba, Spain. The first electric street lighting employed arc lamps, initially the Electric candle, Jablotchkoff candle or Yablochkov candle developed by the Russian Pavel Yablochkov in This was a carbon arc lamp employing alternating current, which ensured that both electrodes were consumed at equal rates. Yablochkov candles were first used to light the Grand Magasins du Louvre, Paris where 8 were deployed. Today, street lighting commonly uses high-intensity discharge lamps, often HPS high pressure sodium lamps. Such lamps provide the greatest amount of photopic illumination for the least consumption of electricity. However when scotopic/photopic light calculations are used, it can been seen how inappropriate HPS lamps are for night lighting. White light sources have been shown to double driver peripheral vision and increase driver brake reaction time at least 25%. When S/P light calculations are used, HPS lamp performance needs to be reduced by a minimum value of 75%. This is now a standard design criteria for Australian roads. 17

2 1.1 The Development of Street Lighting Network in Estonia The streets of Tallinn started regularly to be lit since In 1865 the streets of Tallinn established the first gas lights that were lit every evening and every morning were extinguished by a special person who was responsible for this. The first electric street lights were installed in Tallinn on the Baltic station in A broader transition to electric lighting began in 1915, by the end of the year 1365 gas lamps were replaced with 186 electric lamps. From this time began the rapid development of street lighting, and by 1939 in the streets of Tallinn were 1464 electric lights and 549 gas lamp which had to be turned on and off every night and morning one after another. Its electric network should be built for street lighting. Street electrical network consists of power and controls panels, electric lines,, cross-arms, brackets, grounding and sources of light. In Tallinn by 1963 lines of street networks reached 347 kilometers and a network of street lighting included 8496 lamps. Estonia's new independence period 1991st in Tallinn (together with the cities Saua and Maardu) were street lamps and 1187 kilometers electrical lines from which 688 kilometers (about 58%) were bare wire. Over the past decade the city of Tallinn has gained a qualitatively new level of exterior lighting, and continues the quantitative development Fig. 1. Change a number of street lamp in the period 2-29 Qualitative improvement in the capital of newly independent Estonia began lighting in 1994 when the municipality installed 122 high-pressure sodium lamps (25 W) instead of mercury lamps (4 W) to the Street of Freedom Square in Tallinn and Pärnu road. Compared to the 2 Tallinn has increased 1.7 times a number of sources of lighting and in the 29 it reached 5218 (see Fig.1) Prior to 1997 the increase lighting was immaterial. In 1999 and 2 about 1 lamps were added in the street. Beginning from lamps were added. The peak of development was reached in 26 with 367 sources of lighting. The number on new lighting started to go down after 26. (see Fig. 2). The development of street lighting is displayed in our everyday image of the city. If in early 2, 83,8 km belonging to the city streets were unlit, then by 26 the number of unlit streets reduced to 22,5 km. Nowadays the number of unlit streets became smaller in some times. Instead of poorly-lit lamps up to date ones were installed highlights, many parks were lit as well as "tracks of health". If such development continues, we can hope that Tallinn will soon be called the lighted city. Review of the level of street lighting in Tallinn is shown in Table Fig. 2. Street Lighting growth in period 2-29 To increase stability, improving lighting performance and to ensure the safety much has been done in recent decades. Primary: 1. Most old sources of light, lamps were replaced with modern, economic lamps. The turning year here was 21, when KH Energia-Konsult replaced approximately 26% of city lights for economical lamp. By the end of 29, there are 5218 lamps and from them only 1373 which were produced before 1994; 2. Out of 6 kilometers of aerial non-insulated wire lines wire in 29, remained only 157 km. 3. All 61 switchboards street lighting are modern and all of them are equipped with remote control and monitoring 4. A lot of switchboards of street lighting were installed in the walls of building situated in the old part of Tallinn and they are safe when they are touch. 2 Technical Condition of the Street Lighting Network Network of street lighting is better characterizesed by the time of construction (installation) because quality of build is being developed and up to date materials are used for construction. Switch-distribution boards All distribution boards which were in function up to 1997 were changed. For the first two years these new junction boxes used were produced by ABB firm. Later started to use boxes which were made by KH Energia-Konsult respectively concrete specification of street lighting. Update overview switchboards of electrical networks, see Table

3 Table 1. The Street Lighting Network level in Tallinn at 1. November 29 Lamps, Name Unit Amount From them, which were produced before 1994 The length of transmission line which were set up aerial lines with noninsulated wire pce km aerial cable lines 63 underground cables 96 The hole number of which belongs to the municipality steel pce concrete wooden special ordered 116 Switch distribution boards with system of management and control pce 61 In 2, AS KH Energia-Konsult added switching and lighting control by security system with electronic blocks, which enabled security devices and withdraw the daily organization of the street lighting to a new level to the 4 switchboards boxes and in the 21 the rest of distribution boxes got the same devices. Table 2. Distribution of switching-distribution boards of street lighting network by age The year of Amount, Installation pce All 61 In the meantime, distributors need to renew part of the renovation and upgrading for the following reasons: In connection with the replacement of bare conductors aerial cable lines, 15 sheets of street lighting are in need of alteration. For safety in accordance with the requirements for upgrading routes releaser-switches should be installed in a visible place (it is necessary to install a total of about 8 safety switches, which in turn leads to alterations of installing equipment in parts); The control units which were installed to switchingdistribution boxes in 2 and 21 became obsolete due to the amortization. Due to the fact that fields of electronics an information technology development with an enormous speed, it is necessary to replace the existing control units for a new and improved ones. AS KH Energia-Konsult, which is Tallinn s lighting service provider up to 214 since 25. In the second half of the reconstruction developing new software and controls, and the replacing blocks for the new and modern, has been realized in 26 and 27. Electricity transmission lines Aerial lines with non-insulated wire conductors. After 199 non- insulated wire conductors lines was not used in Tallinn. Thus, the reliability of the electrical characteristics of (the risk for residence) these wires needs replacement by aerial cable lines (Tallinn, Estonian Energia Jaotusvõrk replaced all the common non-insulated wires by aerial cable lines in the years ); Aerial cable lines. The first aerial cable line in Tallinn were built in Today, Tallinn street light network has aerial cable lines as long as 63 kilometers, representing about 37% of the overall length of street lighting network cable lines. 2 / 3 of aerial lines with non- insulated wire were replaced with aerial cable lines. All aerial cables are in a good technical condition, and electrical repair or maintenance, in addition to the regular does not require any additional costs for the period under review. Reconstructed lines should be considered the fact that the new installed aerial cables are existing old posts. Underground cables. Underground cable is more preferable for two reasons: It is invisible and remains visually does not pollute It is though to be safe and reliable. Nowadays a total length of underground cable is 96 kilometers. It is more than 53% of the overall length of street lighting network cable lines. Supports for luminaries In Tallinn the total number of luminaries is 5218 most of them are on the, but the total number of is This is because on several are installed from two to eight luminaries. The following belong to the city and to the Municipal Economy only 25392, the rest belong to Eesti Energia or to the system of public transport. The in the street lighting network are divided in three mostly used types (see Table 3) 172

4 Table 3. Poles types used in the street lighting system in Tallinn Pole type Wooden Concrete Steel Quantity, pce Quantity, % 15,9 35,5 48,6 The condition of the steel which were installed from 1994 can be named as a good one. These steel which were installed before 1994 the big part of them is named as steel with metal cover in the lower part of pole or cast iron should be changed because they got amortized and cracked. The number of concrete in the last ten years has not almost changed. New concrete were installed only in individual cases and in replacing old. The overall situation with concrete among all is the worst. The main reason is their age and, consequently, reinforced concrete and high corrode of metal fitting, which has been intensified by the use of chloride in the streets. The most dangerous thing in the city lighting at the present moment is reinforced concrete which are in a very poor condition. We should not forget that one of the fragile concrete may lead others to draw the line and make them fall it could be dangerous for people and vehicles. Some such accidents have already occurred in recent years. Therefore, the exchange of depreciated concrete in the near future is one of the important components in the network of street lighting. Only of wooden which belongs to the city are used in the street lighting network. Condition of these is satisfactory. 3 Vandalism in the Street Lighting Network The number of cases of vandalism in street lighting network from 2 is shown on fig a 21.a 22.a 23.a 24.a 25.a 26.a 27.a 28.a 29.a fig. 3. The number of cases of vandalism(from 2) As can be seen in the fig. 6 the number of vandalism act in Tallinn is less from 21. All things considered, thanks to security system which was installed in all panels the acts of vandalism are becoming less and less. Breaking panels resulted in switching off street lighting which was a good cause for robbery and mugging. The security system works immediately and the signal goes to the controller. Sound signal can be heard in the place of vandalism. This system enables not to switch off lightning on health paths which can be found in the forest. The average number of vandalism acts in year in different parts is shown in fig. 4, 4, 35, 3, 25, 2, 15, 1, 5, - Haabersti Kristiine Mustamäe Pirita Fig.4.The average number of vandalism acts in year in different parts of Tallinn The Street Lighting System controlling, monitoring and management Street lighting networks differ from others electrical energy consumers, because almost all lamps need to be controlled. In the evening they should be turned on and turned off in the morning. In the first decade when the street lighting appeared special people turned it on and off. When electric street lighting started to be used, people tried to find more easy possibilities of doing it. In the first part of the 2 th century a new method which meant turn on and turn off was used in certain time. In the second half of the 2 th century, street light switching went by a signal, which came from photo sensor. This sensor measures the condition of lighting on the streets. They were put on every group of lamps. For controlling switching on and off the lines of management were introduced. As in this time non-insulated wires were used on some main roads a big and massive network of electrical wires on could be seen. But the main informant about problems in the street lighting was a resident living in town, it tooks him some days. Also night trips were tried for controlling street light. The used photo elements were not perfect, a lot of factors influenced their parameters. For example, the luminaire which was situated on the house near the photo element. For this reason the lighting did not work regularly. There was no information about switching off and about breaking. The whole monitoring ad controlling system is based on GSM data. By this data the central computer controls the work of street lighting in the real time according to the program of turning on and off. A All 61 switching boxes turn on and off during 6 minutes due to the program given. 173

5 The lighting of pedestrian roads in Tallinn are connected with the security signalization. It means that if the breaking or opening of a box of control happens the signal of alarm immediately goes to the control panel in KH Energia-Konsult, also this signal come to trusted people, who organize work and maintenance of street lighting system. Now all switching boxes are connected into one system of controlling and monitoring RVS (fig. 5). Fig. 5. The components of RVS system and communication between RVS and switching panels What is the RVS system? RVS is the system which gives opportunity from the controlling center to involve a great number of panels, to make a lot of switching off, some measures, to keep and store many parameters of system. The functional system is quickly being enlarged. The system consists of: Hard soft (for controller, monitoring, administration); Server and data; Module system of management. Data exchange with server goes with help of the internet and ISDN and GSM. It is possible to use wireless Bluetooth PDA- tester in order to control and to test outdoor. Summary Street lighting, by nature, was one of the most public aspects of the technological revolution. Sometimes with a splash, at other times nearly invisibly. The development of street lighting last 4 years could be followed on some figures. In 1963 there were 8496 sources of light in Tallinn, only 71 were sodium. In 1978 first sodium lamps were installed which produced a better lighting in the street. In 1991 the city already had lamps. In this time, technology seems to promise the chance to relight cities in ways that better complement the environment. Therefore, in 1994 morally old lamps were changed into new high-pressure sodium lamps. During the last years thanks to the maintenance KH Energia-Konsult street lighting is being developed rather quickly. Nowadays there are 5218 in Tallinn, most of them modern and changed. Installing of the system of monitoring and control strongly influences the management and monitoring. The system enables to send signals on 61 panels about 3 parameters and to find out damages in the system in 4 minutes. If the door of the panel is open, alarm signal appears immediately. In 26 the acts of vandalism were 17 times less than in 2. The number of broken panels decreased 3 times. Nowadays the number of acts of vandalism a little bit increased. No one can name the reasons why it happen, may be one of them is the economic situation it the country which effects on people behavior negatively. The development of street lighting should not stop on achieved because the street lighting is an essential public service that provides a safer environment to its users. References 1. Wikipedia webpage: 2. Tallinna tänavavalgustus möödunud sajanditel..robert Nerman, Postimees Tallinna Välisvalgustuskava aastateks Information about data and numbers AS KH Energia-Konsult, in the end of November