Rail Electrification Systems - Learn EVERYTHING About Them!

foreign explained as our patreon shows today's topic we'll represent an overview of the Railway electrification system we tried not to go too much into technical details but rather to talk about the basic principles and essential concepts related to electrification systems including the reasons why there are so many different types but before proceeding with the topic let us invite you to hit the Subscribe Button as only 11 of the total watch time on our channel in the last 90 days was achieved by subscribers we are asking for that one simple click after all it's free and in addition you can click the Bell to get notification for every next new video and if you are new on the channel well you have a choice of over 70 videos to watch and learn about railways the story of the electrification of Railways starts you guess with the appearance of electric locomotives the first known primitive electrical locomotive powered by galvanic cells was built in 1837 by chemist Robert Davidson at the time The Limited power from batteries prevented its General use the first electric passenger train was presented by Werner Von Simmons at the Berlin industrial Exposition in 1879. the first significant development of Railway electrification was prolonged until the first World War this was because the electric traction had yet to meet the unique requirements of Railway traffic another reason for the slow development of the Railway electrification was insufficiently developed general electrification for households industry Etc also steam traction reached a high level of development and as such it met all needs of Transport demand only after the first world war did the railway electrification start its development bearing in mind that large power plants appeared as well as networks of overhead power lines for the transmission of high power electricity over long distances this also gave a boost to the further development of electric traction Motors as the use of Railways group entused the need for more powerful locomotives it turned out that with sufficiently high traffic density electric traction was actually more profitable than Steam at the most superficial level the electrification system includes the power supply system that powers the electric motor on the train the rail track is used as a return connection needed to complete the electrical circuit and allow current to flow to enable safe and reliable Railway traffic the power supply system must be stable and constant you are probably aware that there are different Railway electrification systems which are primarily characterized by The Continuous Improvement so in some countries the systems that were initially installed remained and in some others which entered the electrification process later they decided to deploy the best system available at the time at the same time some countries chose to have both an initial identification system and to deploy other or newer railway lines let's now put our focus on all those different systems the classification of the electrification systems is made according to several criteria regarding voltages European and international standards recognize six standard systems shown in the table where the division is made according to the nominal voltage and its characteristics now you can see the variety of these systems deployed in Europe with the presence of all six classified systems this is the result of the fact that European Railways developed independently from one another within the borders of national countries and on European level with interoperability principles included which is nowadays one of the keywords of European transport policy makers here you could also notice in the previous table that there is a division according to the type of electricity we have systems based on direct current and based on an alternating current the earliest systems used DC since AC was not yet sufficiently researched but also high voltage insulating material not yet widely available most trams trolley networks and Subway systems use DC voltages between 600 and 750 volts system sweetheart voltage from 1. 5 kilowatts to 3 kilowatts DC are mainly used as a primary train power supply thus 1.

5 kilowatts DC is used in the Netherlands Indonesia Ireland partly in Japan France Australia and some Interurban lines in the United States New Zealand and Singapore three kilowatts DC is used in Belgium Italy Spain Poland Slovakia Slovenia South Africa Chile the northern portion of the Czech Republic but also the former republics of the Soviet Union and the Netherlands only few kilometers between Maastricht and Belgium but even at 3 kilowatts the current needed to power a heavy train can be excessive particularly in Rural and mountainous areas thus electrified Railways adopted alternating current along with the electric power distribution system deployment the deployment of the AC power grid with 50 hertz began at the beginning of the 20th century but the series warned Motors of that time had problems using current with such high frequency that caused overheating and serious effects at motor collectors this was sold by Shifting The Frequency slightly away from exactly one-third the grid frequency I. E 15 kilowatts and 16. 7 Hertz this frequency value was arbitrarily chosen to remain within the tolerance of existing traction Motors the first locomotive powered at 15 Hertz and 16.

7 Hertz was built in 1905 in Switzerland from that moment the electrification of Railways could begin to be applied on a massive scale this current system was adopted in 1909 by Switzerland and Germany in the following year by Sweden in 1914 by Austria and 1922 by Norway by 1928 about 10 000 kilometers of rail tracks worldwide were electrified at 15 kilowatts 16. 7 Hertz the use of AC with a frequency from the national power grid of 50 hertz was first successful in Hungary when a Hungarian engineer Kalman condo managed to design a motor that used 16 kilowatts 50 hertz with a synchronous traction all the kind of solutions showed a way for the future rally operators outside of Hungary lacked interest in the design the first Railway to use 50hz was completed in 1936 when the deutera expand deployed a 20 kilowatts 50 hertz AC system on the rail section between Freiburg and neustad this part of Germany was in the French zone of occupation after 1945. as a result of examining the German system in 1951 the French Railways electrified one line in southern France initially at the same 20 kilowatts but converted to 25 in 1953.

the 25 kilowatts 50 hertz system was then adopted as the standard in France but since a substantial length of lines south of Paris had already been electrified at 1. 5 kilowatts DC French Railways also continued some major new DC electrification projects one of the disadvantages of the 16. 7 Hertz locomotives compared to 50 or 60 hertz is the heavier Transformer required to reduce the voltage to the level used by these engines and their speed control gear the heavier Transformers also lead to heavier axle loads than those of higher frequency this in turn leads to increased track wear and increases the need for more frequent track maintenance the choice of 25 kilowatts 50 hertz was related to the efficiency of power transmission as a function of voltage and cost not based on a neat ratio of the supply voltage a higher voltage for a given power level allows for a lower current and usually better efficiency at higher cost for high voltage equipment it was founded at 25 kilowatts was an optimal point where a higher voltage would still improve efficiency but not significantly about the higher costs incurred by the need for larger insulators and greater clearance from structures this is why most countries which later started electrification programs electrified their Railways at the utility frequency of 50 60 hertz for example despite bordering only 15 kilowatts territory Denmark decided to Electrify their Mainline Railways at 25 kilowatts 50 hertz this variety of systems in Europe has already mentioned along with many other technical aspects caused a lack of interoperability from the 1950s onwards the emerging formation of the European Union and the consequent increase in the amount of cross-border traffic along with the addition of a 25 kilowatts 50 hertz AC system in France in addition to the older 1.

5 kilowatts DC gave rise to the need for multi-voltage locomotives and emus also at the beginning of the 21st century European Railway legislation liberalized cross-border Freight traffic creating a demand for locomotives that could work between EU countries with different electrification systems that created practically a new market for multi-voltage vehicles some locomotives and emus are equipped to operate under four different voltages 25 kilowatts AC 15 kilowatts AC 3000 volts DC and 1500 volts DC modern Electronics makes this possible with relative ease and cross-volted travel is now possible without changing locomotives in addition to this classification there is also a division according to the power supply of moving trains namely there are so-called traction or feeder substations that have the task of converting electric power from the form provided by the electrical power industry for public utility service to an appropriate voltage current type and frequency they Supply continuous conductor running along the rail track that usually takes one of two forms an overhead line or a third rail which further feeds the train to make a complete circuit from the source of energy to the consuming item and back to the source a return conductor is needed to make the system function for this problem a simple solution is found still rails are used as shown in the video the number and location of substations depend on the electrification system for example for a 1. 5 kilowatts DC system substations are located every 10 to 15 kilometers while for a 25 kilowatts 50 hertz system they are located at a distance of 40 to 60 kilometers for the 750 volt system they are placed at a distance of 3 kilometers the reason is that with DC Systems there are significant transmission system losses as the distance between Supply connections increases which is compensated for by installing substations more often the power supply system via the third rail is an option for system sub to 1. 5 kilowatts while all others use overhead lines we can safely see that third rail systems almost exclusively use DC distribution awesome the third rail is more compact than overhead wires and can be used in smaller diameter tunnels which is a crucial factor for Subway systems the third rail can be designed to use top contact side contact or bottom contact with safety Shields Incorporated carried by the rail itself in practice the maximum speed of trains on third rail systems is limited to 160 kilometers per hour because above that speed reliable contact between the train and the rail cannot be maintained at this point corrosion is always a factor to be considered in Electric Supply systems particularly DC Systems the tendency of return currents to wander away from the running rails into the ground can set up electrolysis with water pipes and similar metallics this was well understood in the late 19th century and was one of the reasons why a London Underground Railways adopted a fully insulated DC system with a separate negative return reel as well as a positive rail the so-called four-rail system on the London Underground a top contact third rail is beside the track energized at plus 420 volts DC and a top contact for trail is located centrally between the running rails at minus 210 volts DC which combined to provide a traction voltage of 630 volts DC to enable higher chain speeds reduce the number of required substations reduce the risk that the third rail has on the safety of trespassers and track workers and enable more efficient rail traffic and overhead line was introduced which is the name that Railway Engineers use for the Assembly of masts gantries and wires found along the electrified railways this is also called overhead continuary overhead contact system or overhead Line Equipment but we will stick to the term used by the international Union of railways an overhead line basically has a few standard components to collect the required current from the system trains use a device called a pantograph that presses against the underside of the contact wire which represents the point of contact between the train and the overhead line as the pentograph moves under the contact wire after a certain period of time the carbon inserts on top of the pantograph becomes worn that is why the contact wire is designed and deployed in a zigzag path to avoid varying a Groove in the pantograph to achieve good high-speed current collection keeping the contact wire geometry within defined limits is necessary this is achieved by making the contact wire as stationary as possible so that power can flow uninterrupted to the train and minimizing the wear of the system to achieve this the contact wire is tensioned between support structures so that it can withstand deflection by high winds and extreme temperatures this ensures that current passes to the train in all weather even at high speeds the contact wire is suspended from vertical cables called the droppers supported by a longitudinal cable called The catenary Wire the continuary and contact wire span between support structures masts or steel frames the support structures are typically spaced approximately 50 meters apart depending on the alignment of the Railway line cutenary wires are kept in mechanical tension because the pantograph causes mechanical oscillations in the wire and the wave must travel faster than the train to avoid producing standing waves that would cause wire breakage for medium and high speeds the wires are generally tensioned by weights or occasionally by hydraulic tensioners the task of your headline on the electrified Railway is to supply vehicles with the necessary energy for their movement at all times and under all conditions for that purpose its role is irreplaceable while one electric locomotive that is broken can be replaced by another and the power supply of one substation that is disconnected can be taken over by neighboring once until then the role of the overhead line cannot be taken over by any other element to allow maintenance and repair of faults on the overhead line without turning off the entire system the line is broken into electrically separated portions known as neutral sections the first is a complete switch to neutral section this consists of separate insulated lengths of contact wire in the overlap between two regular sections the insulated neutral sections are connected to the normal contact wires base switches which are operated automatically by passing trains thereby maintaining an unbroken electrical supply the second type of neutral section is the short length of non-conducting material spliced into the contact wire to enable local lengths of wire to be isolated I.